NAU8822AYG

NAU8822A NAU8822A 24-bit Stereo Audio CODEC with Speaker Driver GENERAL DESCRIPTION The NAU8822A is a low power, high quality CODEC for portable and general purpose audio applications. In addition to precision 24-bit stereo ADCs and DACs device integrates a broad range of additional functions to simplify implementation of complete audio system solutions. The NAU8822A includes drivers for speaker, headphone, and differential or stereo line outputs, and integrates preamps for stereo differential microphones, significantly reducing external component requirements. Also, a fractional PLL is available to accurately generate any audio sample rate for the CODEC using any commonly available system clock from 8MHz through 33MHz. Advanced on-chip digital signal processing includes a 5-band equalizer, a 3-D audio enhancer, a mixed-signal automatic level control for the microphone or line input through the ADC, and a digital limiter/dynamic-rangecompressor (DRC) function for the playback path. Additional digital filtering options are available in the ADC path, to simplify implementation of specific application requirements such as “wind noise reduction” and speech band enhancement. The digital audio input/output interface can operate as either a master or a slave. The NAU8822A operates with analog supply voltages from 2.5V to 3.6V, while the digital core can operate at 1.7V to conserve power. The loudspeaker BTL output pair and two auxiliary line outputs can operate using a 5V supply to increase output power capability, enabling the NAU8822A to drive 1 Watt into an external speaker. Internal register controls enable flexible power saving modes by powering down sub-sections of the chip under software control. The NAU8822A is specified for operation from -40°C to +85°C. Automotive grade AEC-Q100 qualification & TS16949 compliant device is available upon request. FEATURES         DAC: 94dB SNR and -84dB THD (“A” weighted) ADC: 90dB SNR and -80dB THD (“A” weighted) Integrated BTL speaker driver: 1W into 8Ω Integrated head-phone driver: 40mW into 16Ω Integrated programmable microphone amplifier Integrated line input and line output On-chip PLL Integrated DSP with specific functions: • 5-band equalizer • 3-D audio enhancement • Input automatic level control (ALC/AGC)/limiter • Output dynamic-range-compressor/limiter • Notch filter and high pass filter Oct 20, 2021      Standard audio interfaces: PCM and I2S Serial control interfaces with read/write capability Real-time readback of signal level and DSP status Supports any sample rate from 8kHz to 48kHz Industrial temperature range: –40°C to +85°C APPLICATIONS         Page 1 of 92 Personal Media Players Smartphones Personal Navigation Devices Portable Game Players Camcorders Digital Still Cameras Portable TVs Stereo Bluetooth Headsets Rev 3.2 NAU8822A Headphones/ Line drivers LAUXIN AUXOUT2 RAUXIN ADC Filter LLIN LADC RLIN LMICN LMICP Stereo Microphone Interface Input Mixer DAC Filter Volume Control High Pass & Notch Filters RADC AUXOUT1 LDAC Volume Control LHP Limiter RDAC Output Mixer RHP 5-band EQ BTL Speaker 3D RMICN LSPKOUT RMICP RSPKOUT Digital Audio Interface Microphone Bias I2S Serial Control Interface PCM GPIO PLL LMICP 1 24 24 VSSSPK LMICN 2 23 23 RSPKOUT LLIN/GPIO2 3 22 22 AUXOUT2 RMICP 4 21 21 AUXOUT1 20 20 RAUXIN NAU8822AYG Oct 20, 2021 RHP VSSA VREF VDDSPK LSPKOUT 27 27 26 26 25 25 30 30 28 28 LHP 31 31 29 29 MICBIAS VDDA 32 32 Pinout NAU8822AYG 32-lead QFN RoHS 15 16 CSB/GPIO1 SCLK 14 VDDB SDIO 13 17 17 12 8 VSSD BCLK VDDC MODE 11 18 18 MCLK 7 9 LAUXIN FS 10 RLIN/GPIO3 19 19 DACIN 5 6 ADCOUT RMICN Part Number Dimension Package Package Material NAU8822AYG 5 x 5 mm 32-QFN Pb-Free Page 2 of 92 Rev 3.2 NAU8822A Pin Descriptions Pin # Name Type 1 2 3 LMICP LMICN LLIN/GPIO2 4 5 6 RMICP RMICN RLIN/GPIO3 Analog Input Analog Input Analog Input / Digital I/O Analog Input Analog Input Analog Input / Digital I/O 7 8 9 10 11 12 13 14 15 FS BCLK ADCOUT DACIN MCLK VSSD VDDC VDDB CSB/GPIO1 Digital I/O Digital I/O Digital Output Digital Input Digital Input Supply Supply Supply Digital I/O 16 17 18 19 20 21 22 23 24 SCLK SDIO MODE LAUXIN RAUXIN AUXOUT1 AUXOUT2 RSPKOUT VSSSPK Digital Input Digital I/O Digital Input Analog Input Analog Input Analog Output Analog Output Analog Output Supply 25 26 LSPKOUT VDDSPK Analog Output Supply 27 28 29 30 31 32 VREF VSSA RHP LHP VDDA MICBIAS Reference Supply Analog Output Analog Output Supply Analog Output Oct 20, 2021 Functionality Left MICP Input (common mode) Left MICN Input Left Line Input / alternate Left MICP Input / GPIO2 Right MICP Input (common mode) Right MICN Input Right Line Input/ alternate Right MICP Input / Digital Output In 4-wire mode: Must be used for GPIO3 Digital Audio DAC and ADC Frame Sync Digital Audio Bit Clock Digital Audio ADC Data Output Digital Audio DAC Data Input Master Clock Input Digital Ground Digital Core Supply Digital Buffer (Input/Output) Supply 3-Wire MPU Chip Select or GPIO1 multifunction input/output 3-Wire MPU Clock Input / 2-Wire MPU Clock Input 3-Wire MPU Data Input / 2-Wire MPU Data I/O Control Interface Mode Selection Pin Left Auxiliary Input Right Auxiliary Input Headphone Ground / Mono Mixed Output / Line Output Headphone Ground / Line Output BTL Speaker Positive Output or Right high current output Speaker Ground (ground pin for RSPKOUT, LSPKOUT, AUXOUT2 and AUXTOUT1 output drivers) BTL Speaker Negative Output or Left high current output Speaker Supply (power supply pin for RSPKOUT, LSPKOUT, AUXOUT2 and AUXTOUT1 output drivers) Decoupling for Midrail Reference Voltage Analog Ground Headphone Positive Output / Line Output Right Headphone Negative Output / Line Output Left Analog Power Supply Microphone Bias Page 3 of 92 Rev 3.2 Oct 20, 2021 Page 4 of 92 MICBIAS VREF RAUXIN RLIN RMICP RMICN LLIN LMICP LMICN LAUXIN 32 27 20 6 4 5 3 1 2 19 PLL MICROPHONE BIAS R R VDDA + - + Σ LADC MIX/BOOST 12 VSSD 7 9 BCLK FS ADCOUT 8 31 VDDA 28 VSSA DACIN 10 RADC Notch Filter ALC HPF RADC AUDIO INTERFACE (PCM/IIS) RADC MIX/BOOST Σ ALC Control 13 14 - VDDC VDDB 11 16 17 18 CSB/ MODE GPIO1 15 CONTROL INTERFACE (2-, 3- and 4-wire) RDAC Limiter LDAC MCLK SCLK SDIO RINMIX 24 VSSSPK 5 Band EQ 3D LINMIX 26 VDDSPK RMIX Σ RMAIN MIXER LMAIN MIXER Σ LMIX LDAC LINMIX RMIX LMIX RDAC LDAC RINMIX Σ Σ Σ RSPK SUBMIXER AUX2 MIXER AUX1 MIXER -6dB Normal -1.0X +1.5X -1.0X +1.5X -1.0X +1.5X -1.0X +1.5X 23 25 29 30 22 21 RSPKOUT LSPKOUT RHP LHP AUXOUT2 AUXOUT1 NAU8822A Figure 1: NAU8822ABlock Diagram Rev 3.2 NAU8822A Electrical Characteristics Conditions: VDDC = 1.8V, VDDA = VDDB = VDDSPK = 3.3V, MCLK = 12.88MHz, TA = +25°C, 1kHz signal, fs = 48kHz, 24-bit audio data, 64X oversampling rate, unless otherwise stated. Parameter Analog to Digital Converter (ADC) Full scale input signal 1 Symbol Comments/Conditions PGABST = 0dB PGAGAIN = 0dB Signal-to-noise ratio SNR Gain = 0dB, A-weighted Total harmonic distortion 2 THD+N Input = -3dB FS input Channel separation 1kHz input signal Digital to Analog Converter (DAC) driving RHP / LHP with 10kΩ / 50pF load Full-scale output Gain paths all at 0dB gain Min Typ VINFS Signal-to-noise ratio SNR A-weighted Total harmonic distortion 2 THD+N RL = 10kΩ; full-scale signal Channel separation 1kHz input signal Output Mixers Maximum PGA gain into mixer Minimum PGA gain into mixer PGA gain step into mixer Guaranteed monotonic Speaker Output (RSPKOUT / LSPKOUT with 8Ω bridge-tied-load) Full scale output 4 SPKBST = 1 tbd 1.0 0 90 -80 103 Max tbd VDDA / 3.3 88 94 -84 96 Units Vrms dBV dB dB dB Vrms dB dB dB tbd +6 -15 3 dB dB dB VCCSPK / 3.3 Vrms (VCCSPK / 3.3) * 1.5 Vrms Po= 200mW, VDDSPK=3.3V Po= 320mW, VDDSPK = 3.3V Po= 860mW, VDDSPK = 5V Po= 1000mW, VDDSPK = 5V VDDSPK = 3.3V *63 dB -64 dB -60 dB -36 dB 91 dB VDDSPK=5V 90 dB VDDSPK = 3.3V 81 dB VDDSPK = 5V (boost) 72 dB Analog Outputs (RHP / LHP; RSPKOUT / LSPKOUT) Maximum programmable gain Minimum programmable gain Programmable gain step size Guaranteed monotonic Mute attenuation 1kHz full scale signal +6 -57 1 85 dB dB dB dB SPKBST = 0 Total harmonic distortion 2 Signal-to-noise ratio Power supply rejection ratio (50Hz - 22kHz) Oct 20, 2021 THD+N SNR PSRR Page 5 of 92 Rev 3.2 NAU8822A Electrical Characteristics, cont’d. Conditions: VDDC = 1.8V, VDDA = VDDB = VDDSPK = 3.3V, MCLK = 12.288MHz, TA = +25°C, 1kHz signal, fs = 48kHz, 24-bit audio data, unless otherwise stated. Parameter Symbol Headphone Output (RHP / LHP with 32Ω load) 0dB full scale output voltage Signal-to-noise ratio SNR Total harmonic distortion 2 THD+N AUXOUT1 / AUXOUT2 with 10kΩ / 50pF load Full scale output Signal-to-noise ratio Total harmonic distortion 2 Channel separation Power supply rejection ratio (50Hz - 22kHz) Comments/Conditions Min Typ Max AVDD / 3.3 92 80 Vrms dB dB 85 dB AUX1BST = 0 AUX2BST = 0 VDDSPK / 3.3 Vrms AUX1BST = 1 AUX2BST = 1 (VDDSPK / 3.3) * 1.5 Vrms 87 -83 99 53 dB dB dB dB 56 dB A-weighted RL = 16Ω, Po = 20mW, VDDA = 3.3V RL = 32Ω, Po = 20mW, VDDA = 3.3V SNR THD+N 1kHz signal PSRR VDDSPK = 5V (boost) Microphone Inputs (LMICP, LMICN, RMICP, RMICN, LLIN, RLIN) and Programmable Gain Amplifier (PGA) Full scale input signal 1 PGABST = 0dB 1.0 PGAGAIN = 0dB 0 Programmable gain -12 35.25 Programmable gain step size Guaranteed Monotonic 0.75 Mute Attenuation 120 Input resistance Inverting Input PGA Gain = 35.25dB 1.6 PGA Gain = 0dB 47 PGA Gain = -12dB 75 94 Non-inverting Input Input capacitance 10 PGA equivalent input noise 0 to 20kHz, Gain set to 120 35.25dB Input Boost Mixer Gain boost Boost disabled 0 Boost enabled 20 Gain range LLIN / RLIN or -12 6 LAUXIN / RAUXIN to boost/mixer Gain step size to boost/mixer 3 Auxiliary Analog Inputs (LAUXIN, RAUXIN) Full scale input signal 1 Gain = 0dB 1.0 0 Input resistance Aux direct-to-out path, only Input gain = +6.0dB 20 Input gain = 0.0dB 40 Input gain = -12dB 159 Input capacitance 10 Oct 20, 2021 Units Page 6 of 92 Vrms dBV dB dB dB kΩ kΩ kΩ kΩ pF µV dB dB dB dB Vrms dBV Rev 3.2 kΩ kΩ kΩ pF NAU8822A Electrical Characteristics, cont’d. Conditions: VDDC = 1.8V, VDDA = VDDB = VDDSPK = 3.3V, MCLK = 12.88MHz, TA = +25°C, 1kHz signal, fs = 48kHz, 24-bit audio data, unless otherwise stated. Parameter Symbol Comments/Conditions Automatic Level Control (ALC) & Limiter: ADC path only Target record level Programmable gain Gain hold time 3 tHOLD Doubles every gain step, with 16 steps total Gain ramp-up (decay) 3 tDCY ALC Mode ALC = 0 Limiter Mode ALC = 1 Gain ramp-down (attack) 3 tATK ALC Mode ALC = 0 Limiter Mode ALC = 1 Mute Attenuation Microphone Bias Bias voltage VMICBIAS See Figure 3 Bias current source Output noise voltage Digital Input/Output Input HIGH level IMICBIAS Vn 1kHz to 20kHz VIL Min Typ Max Units -22.5 -1.5 -12 35.25 0 / 2.67 / 5.33 / … / 43691 dBFS dB ms 4 / 8 / 16 / … / 4096 ms 1 / 2 / 4 / … / 1024 ms 1 / 2 / 4 / … / 1024 ms 0.25 / 0.5 / 1 / … / 128 ms 120 dB 0.50, 0.60,0.65, 0.70, 0.75, 0.85, or 0.90 3 14 VDDA VDDA mA nV/√Hz 0.7 * VDDC Input LOW level VIH Output HIGH level VOH ILoad = 1mA Output LOW level VOL ILoad = -1mA V 0.3 * VDDC Input capacitance 0.9 * VDDC V V 0.1 * VDDC 10 V pF Notes 1. Full Scale is relative to the magnitude of VDDA and can be calculated as FS = VDDA/3.3. 2. Distortion is measured in the standard way as the combined quantity of distortion products plus noise. The signal level for distortion measurements is at 3dB below full scale, unless otherwise noted. 3. Time values scale proportionally with MCLK. Complete descriptions and definitions for these values are contained in the detailed descriptions of the ALC functionality. 4. With default register settings, SPKVDD should be 1.5xVDDA (but not exceeding maximum recommended operating voltage)to optimize available dynamic range in the AUXOUT1 and AUXOUT2 line output stages. OutputDC bias level is optimized for SPKVDD = 5.0Vdc (boost mode) and VDDA = 3.3Vdc. 5. Unused analog input pins should be left as no-connection. 6. Unused digital input pins should be tied to ground. Oct 20, 2021 Page 7 of 92 Rev 3.2 NAU8822A Absolute Maximum Ratings Condition Min Max Units VDDB, VDDC, VDDA supply voltages -0.3 +3.61 V VDDSPK supply voltage (default register configuration) -0.3 +5.80 V VDDSPK supply voltage (optional low voltage configuration) -0.3 +3.61 V Core Digital Input Voltage range VSSD – 0.3 VDDC + 0.30 V Buffer Digital Input Voltage range VSSD – 0.3 VDDB + 0.30 V Analog Input Voltage range VSSA – 0.3 VDDA + 0.30 V Industrial operating temperature -40 +85 °C Storage temperature range -65 +150 °C CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely influence product reliability and result in failures not covered by warranty. Operating Conditions Condition Symbol Min Digital supply range (Core) VDDC Digital supply range (Buffer) Analog supply range Typical Max Units 1.65 3.60 V VDDB 1.65 3.60 V VDDA 2.50 3.60 V Speaker supply (SPKBST=0) VDDSPK 2.50 5.50 V Speaker supply (SPKBST=1) VDDSPK 2.50 5.50 V Ground VSSD VSSA VSSSPK 0 V 1. VDDA must be ≥ VDDC. 2. VDDB must be ≥ VDDC. Oct 20, 2021 Page 8 of 92 Rev 3.2 NAU8822A Table of Contents 1 2 3 GENERAL DESCRIPTION ............................................................................................................................. 11 POWER SUPPLY............................................................................................................................................. 13 INPUT PATH DETAILED DESCRIPTIONS.................................................................................................. 14 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 4 Programmable Gain Amplifier (PGA) ......................................................................................................... 14 Positive Microphone Input (MICP) .............................................................................................................. 15 Negative Microphone Input (MICN) ............................................................................................................ 16 Microphone biasing .................................................................................................................................... 17 Line/Aux Input Impedance and Variable Gain Stage Topology .................................................................. 17 Left and Right Line Inputs (LLIN and RLIN) ............................................................................................... 19 Auxiliary inputs (LAUXIN, RAUXIN) ........................................................................................................... 19 ADC Mix/Boost Stage................................................................................................................................. 19 Input Limiter / Automatic Level Control (ALC) ............................................................................................ 20 ALCPeak Limiter Function.......................................................................................................................... 21 Noise Gate (Normal Mode Only) ................................................................................................................ 22 ALC Example with ALC Min/Max Limits and Noise Gate Operation........................................................... 24 Limiter Mode .............................................................................................................................................. 25 ADC DIGITAL BLOCK .................................................................................................................................. 26 4.1 4.2 4.3 4.4 5 Sampling / Oversampling Rate, Polarity Control, Digital Passthrough ....................................................... 26 ADC Digital Volume Control and Update Bit Functionality ......................................................................... 27 ADC Programmable HighPass Filter .......................................................................................................... 27 Programmable Notch Filter ........................................................................................................................ 27 DAC DIGITAL BLOCK .................................................................................................................................. 29 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 6 DAC Soft Mute ........................................................................................................................................... 29 DAC AutoMute ........................................................................................................................................... 29 DAC Sampling / Oversampling Rate, Polarity Control, Digital Passthrough ............................................... 29 DAC Digital Volume Control and Update Bit Functionality ......................................................................... 30 DACAutomaticOutputPeak Limiter / Volume Boost .................................................................................... 30 5-Band Equalizer ........................................................................................................................................ 31 3D Stereo Enhancement ............................................................................................................................ 32 Companding ............................................................................................................................................... 32 µ-law .......................................................................................................................................................... 32 A-law .......................................................................................................................................................... 32 8-bit Word Length ....................................................................................................................................... 33 ANALOG OUTPUTS....................................................................................................................................... 33 6.1 6.2 6.3 6.4 6.5 6.6 7 Main Mixers (LMAIN MIX and RMAIN MIX) ............................................................................................... 33 Auxiliary Mixers (AUX1 MIXER and AUX2 MIXER).................................................................................... 34 Right Speaker Submixer ............................................................................................................................ 34 Headphone Outputs (LHP and RHP) ......................................................................................................... 34 Speaker Outputs ........................................................................................................................................ 35 Auxiliary Outputs ........................................................................................................................................ 36 MISCELLANEOUS FUNCTIONS .................................................................................................................. 36 7.1 7.2 7.3 8 Slow Timer Clock ....................................................................................................................................... 36 General Purpose Inputs and Outputs (GPIO1, GPIO2, GPIO3) and Jack Detection ................................. 37 Automated Features Linked to Jack Detection ........................................................................................... 37 CLOCK SELECTION AND GENERATION .................................................................................................. 38 8.1 Phase Locked Loop (PLL) General Description ......................................................................................... 39 Oct 20, 2021 Page 9 of 92 Rev 3.2 NAU8822A 8.2 9 CSB/GPIO1 as PLL output ......................................................................................................................... 40 CONTROL INTERFACES .............................................................................................................................. 41 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 9.10 9.11 10 DIGITAL AUDIO INTERFACES ................................................................................................................... 46 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 11 Right-Justified Audio Data .......................................................................................................................... 46 Left-Justified Audio Data ............................................................................................................................ 46 I2S Audio Data ............................................................................................................................................ 47 PCMA Audio Data ...................................................................................................................................... 47 PCMB Audio Data ...................................................................................................................................... 48 PCM Time Slot Audio Data ........................................................................................................................ 48 Control Interface Timing ............................................................................................................................. 50 Audio Interface Timing: .............................................................................................................................. 52 APPLICATION INFORMATION ................................................................................................................... 53 11.1 11.2 11.3 11.4 12 13 Selection of Control Mode .......................................................................................................................... 41 2-Wire-Serial Control Mode (I2C Style Interface) ........................................................................................ 41 2-Wire Protocol Convention ....................................................................................................................... 41 2-Wire Write Operation............................................................................................................................... 42 2-Wire Read Operation .............................................................................................................................. 42 SPI Control Interface Modes ...................................................................................................................... 43 SPI 3-Wire Write Operation ........................................................................................................................ 43 SPI 4-Wire 24-bit Write and 32-bit Read Operation................................................................................... 44 SPI 4-Wire Write Operation ...................................................................................................................... 44 SPI 4-Wire Read Operation........................................................................................................................ 45 Software Reset........................................................................................................................................... 45 Typical Application Schematic .................................................................................................................... 53 Recommended power up and power down sequences .............................................................................. 54 Power Consumption ................................................................................................................................... 56 Supply Currents of Specific Blocks............................................................................................................. 57 APPENDIX A: DIGITAL FILTER CHARACTERISTICS ............................................................................ 59 APPENDIX B: COMPANDING TABLES ..................................................................................................... 64 13.1 13.2 µ-Law / A-Law Codes for Zero and Full Scale ............................................................................................ 64 µ-Law / A-Law Output Codes (Digital mW)................................................................................................. 64 14 PPENDIX C: CONTROL AND STATUS REGISTERS ............................................................................. 65 15 APPENDIX D: REGISTER OVERVIEW ..................................................................................................... 86 16 PACKAGE DIMENSIONS .............................................................................................................................. 89 17 ORDERING INFORMATION ......................................................................................................................... 90 18 REVISION HISTORY...................................................................................................................................... 91 IMPORTANT NOTICE ............................................................................................................................................ 92 Oct 20, 2021 Page 10 of 92 Rev 3.2 NAU8822A 1 General Description The NAU8822A delivers reduced out-of-band noise energy, improved ALC and DSP signal processing, read-out capability of real-time signal level, readout of DSP status, and added controls for industry leading pop/click noise management. Additionally, handling of settings for 5-volt and 3-volt operation are simplified, and all registers unique to Nuvoton are moved to higher addresses. This makes the part a direct hardware and software drop-in replacement for common industry parts. The NAU8822A is a stereo part with identical left and right channels that share common support elements. Additionally, the right channel auxiliary output path includes a dedicated submixer that supports mixing the right auxiliary input directly into the right speaker output driver. This enables the right speaker channel to output audio that is not present on any other output. 1.1.1 Analog Inputs All inputs, except for the wide range programmable amplifier (PGA), have available analog input gain conditioning of -15dB through +6dB in 3dB steps. All inputs also have individual muting functions with excellent channel isolation and off-isolation from all outputs. All inputs are suitable for full quality, high bandwidth signals. Each of the left-right stereo channels includes a low noise differential PGA amplifier, programmable for high-gain input. This may be used for a microphone level through line level source. Gain may be set from +35.25db through 12dB at the analog difference-amplifier type programmable amplifier input stage. A separate additional 20dB analog gain is available on this input path, between the PGA output and ADC mixer input. The output of the ADC mixer may be routed to the ADC and/or analog bypass to the analog output sections. Each channel also has a line level input. This input may be routed to the input PGA, and/or directly to the ADC input mixer. Each channel has a separate additional auxiliary input. This is a line level input which may be routed the ADC input mixer and/or directly to the analog output mixers. 1.1.2 Analog Outputs There are six high current analog audio outputs. These are very flexible outputs that can be used individually or in stereo pairs for a wide range of end uses. However, these outputs are optimized for specific functions and are described in this section using the functional names that are applicable to those optimized functions. Each output receives its signal source from built-in analog output mixers. These mixers enable a wide range of signal combinations, including muting of all sources. Additionally, each output has a programmable gain function, output mute function, and output disable function. The RHP and LHP headphone outputs are optimized for driving a stereo pair of headphones, and are powered from the main analog voltage supply rail, VDDA. These outputs may be coupled using traditional DC blocking series capacitors. Alternatively, these may be configured in a no-capacitor DC coupled design using a virtual ground at ½ VDDA provided by an AUXOUT analog output operating in the non-boost output mode. The AUXOUT1 and AUXOUT2 analog outputs are powered from the VDDSPK supply rail and VSSSPK ground return path. The supply rail may be the same as VDDA, or may be a separate voltage up to 5.5Vdc. This higher voltage enables these outputs to have an increased output voltage range and greater output power capability. The RSPKOUT and LSPKOUT loudspeaker outputs are powered from the VDDSPK power supply rail and VSSGND ground return path. LSPKOUT receives its audio signal via an additional submixer. This submixer supports combining a traditional alert sound (from the RAUXIN input) with the right channel headphone output mixer signal. This submixer also provides the signal invert function that is necessary for the normal BTL (Bridge Tied Load) configuration used to drive a high power external loudspeaker. Alternatively, each loudspeaker output may be used individually as a separate high current analog output driver. A programmable low-noise MICBIAS microphone bias supply output is included. This is suitable for both conventional electret (ECM) type microphone, and to power the newer MEMS all-silicon type microphones. Oct 20, 2021 Page 11 of 92 Rev 3.2 NAU8822A 1.1.3 ADC, DAC, and Digital Signal Processing Each left and right channel has an independent high quality ADC and DAC associated with it. These are high performance, 24-bit delta-sigma converters that are suitable for a very wide range of applications. The ADC and DAC functions are each individually supported by powerful analog mixing and routing. The ADC output may be routed to the digital output path and/or to the input of the DAC in a digital pass-through mode. The ADC and DAC blocks are also supported by advanced digital signal processing subsystems that enable a very wide range of programmable signal conditioning and signal optimizing functions. All digital processing is with 24-bit precision, as to minimize processing artifacts and maximize the audio dynamic range supported by the NAU8822A. The ADCs are supported by a wide range, mixed-mode Automatic Level Control (ALC), a high pass filter, and a notch filter. All of these features are optional and highly programmable. The high pass filter function is intended for DCblocking or low frequency noise reduction, such as to reduce unwanted ambient noise or “wind noise” on a microphone input. The notch filter may be programmed to greatly reduce a specific frequency band or frequency, such as a 50Hz, 60Hz, or 217Hz unwanted noise. The DACs are supported by a programmable limiter/DRC (Dynamic Range Compressor). This is useful to optimize the output level for various applications and for use with small loudspeakers. This is an optional feature that may be programmed to limit the maximum output level and/or boost an output level that is too small. Digital signal processing is also provided for a 3D Audio Enhancement function, and for a 5-Band Equalizer. These features are optional, and are programmable over wide ranges. This pair ofdigital processing features may be applied jointly to either the ADC audio path or to the DAC audio path, but not to both paths simultaneously. 1.1.4 Realtime Signal Level Readout and DSP Status In addition to general read-back ability of all its registers, the NAU8822A includes powerful capacities to readback signal related DSP information not possible with almost any other CODEC. In conjunction with the ALC, the software by means of the readback function can determine the realtime signal level at the inputs, as well as the realtime actual gain setting being used by the ALC. Additionally, other signal related information can also be determined, such as the Noise Gate on/off status and Automute/Softmute function status. These greatly enhance both the ability to optimize software and to enhance dynamic end product functionality. 1.1.5 Digital Interfaces Command and control of the device is accomplished using a 2-wire/3-wire/4-wire serial control interface. This is a simple, but highly flexible interface that is compatible with many commonly used command and control serial data protocols and host drivers. Digital audio input/output data streams are transferred to and from the device separately from command and control. The digital audio data interface supports either I2S or PCM audio data protocols, and is compatible with commonly used industry standard devices that follow either of these two serial data formats. 1.1.6 Clock Requirements The clocking signals required for the audio signal processing, audio data I/O, and control logic may be provided externally, or by optional operation of a built-in PLL (Phase Locked Loop). The PLL is provided as a low cost, zero external component count optional method to generate required clocks in almost any system. The PLL is a fractional-N divider type design, which enables generating accurate desired audio sample rates derived from a very wide range of commonly available system clocks. The frequency of the system clock provided as the PLL reference frequency may be any stable frequency in the range between 8MHz and 33MHz. Because the fractional-N multiplication factor is a very high precision 24-bit value, any desired sample rate supported by the NAU8822A can be generated with very high accuracy, typically limited by the accuracy of the external reference frequency. Reference clocks and sample rates outside of these ranges are also possible, but may involve performance tradeoffs and increased design verification. Oct 20, 2021 Page 12 of 92 Rev 3.2 NAU8822A 2 Power Supply This device has been designed to operate reliably using a wide range of power supply conditions and power-on/poweroff sequences. There are no special requirements for the sequence or rate at which the various power supply pins change. Any supply can rise or fall at any time without harm to the device. However, pops and clicks may result from some sequences. Optimum handling of hardware and software power-on and power-off sequencing is described in more detail in the Applications section of this document. 2.1.1 Power-On Reset The NAU8822A does not have an external reset pin. The device reset function is automatically generated internally when power supplies are too low for reliable operation. The internal reset is generated any time that either VDDA or VDDC is lower than is required for reliable maintenance of internal logic conditions. The reset threshold voltage for VDDA and VDDC is approximately 0.5Vdc. If both VDDA and VDDC are being reduced at the same time, the threshold voltage may be slightly lower. Note that these are much lower voltages than are required for normal operation of the chip. These values are mentioned here as general guidance as to overall system design. If either VDDA or VDDC is below its respective threshold voltage, an internal reset condition is asserted. During this time, all registers and controls are set to the hardware determined initial conditions. Software access during this time will be ignored, and any expected actions from software activity will be invalid. When both VDDA and VDDC reach a value above their respective thresholds, an internal reset pulse is generated which extends the reset condition for an additional time. The duration of this extended reset time is approximately 50 microseconds, but not longer than 100 microseconds. The reset condition remains asserted during this time. If either VDDA or VDDC at any time becomes lower than its respective threshold voltage, a new reset condition will result. The reset condition will continue until both VDDA and VDDC again higher than their respective thresholds. After VDDA and VDDC are again both greater than their respective threshold voltage, a new reset pulse will be generated, which again will extend the reset condition for not longer than an additional 100 microseconds. 2.1.2 Power Related Software Considerations There is no direct way for software to determine that the device is actively held in a reset condition. If there is a possibility that software could be accessing the device sooner than 100 microseconds after the VDDA and VDDC supplies are valid, the reset condition can be determined indirectly. This is accomplished by writing a value to any register other than register 0x00, with that value being different than the power-on reset initial values. The optimum choice of register for this purpose may be dependent on the system design, and it is recommended the system engineer choose the register and register test bit for this purpose. After writing the value, software will then read back the same register. When the register test bit reads back as the new value, instead of the power-on reset initial value, software can reliably determine that the reset condition has ended. Although it is not required, it is strongly recommended that a Software Reset command should be issued after poweron and after the power-on reset condition is ended. This will help insure reliable operation under every power sequencing condition that could occur. If there is any possibility that VDDA or VDDC could be unreliable during system operation, software may be designed to monitor whether a power-on reset condition has happened. This can be accomplished by writing a test bit to a register that is different from the power-on initial conditions. This test bit should be a bit that is never used for any other reason, and does not affect desired operation in any way. Then, software at any time can read this bit to determine if a power-on reset condition has occurred. If this bit ever reads back other than the test value, then software can reliably know that a power-on reset event has occurred. Software can subsequently re-initialize the device and the system as required by the system design. 2.1.3 Software Reset All chip registers can be reset to power-on default conditions by writing any value to register 0, using any of the control modes. Writing valid data to any other register disables the reset, but all registers need to have the correct operating data written. See the applications section on powering NAU8822A up for information on avoiding pops and clicks after a software reset. Oct 20, 2021 Page 13 of 92 Rev 3.2 NAU8822A 3 Input Path Detailed Descriptions The NAU8822Aprovides multiple inputs to acquire and process audio signals from microphones or other sources with high fidelity and flexibility. There are left and right input paths, each with three input pins, which can be used to capture signals from single-ended, differential or dual-differential microphones. These input channels each include a programmable gain amplifier (PGA). The outputs of the PGAs, plus two additional auxiliary inputs, are then connected to the input boost/mix stages for maximum flexibility handling various signal sources. All inputs are maintained at a DC bias at approximately ½ of the AVDD supply voltage. Connections to these inputs should be AC-coupled by means of DC blocking capacitors suitable for the device application. Differential microphone input (MICN & MICP pins) and Programmable Gain Amplifier The NAU8822A features a low-noise, high common mode rejection ratio (CMRR), differential microphone input pair, MICP and MICN, which are connected to a PGA gain stage. The differential input structure is essential in noisy digital systems where amplification of low-amplitude analog signals is necessary such as in portable digital media devices and cell phones. Differential inputs very useful to reduce ground noise in systems in which there are ground voltage differences between different chips and other components. When properly implemented, the differential input architecture offers an improved power-supply rejection ratio (PSRR) and higher ground noise immunity. 3.1 Programmable Gain Amplifier (PGA) Each PGA supports three possible inputs, MICP, MICN, and LIN. These are the microphone differential pair and a separate line level input. The PGA has a gain range of -12dB through +35.25dB in evenly spaced decibel increments of 0.75dB. Operation of the PGA is subject to control by the following registers: R2 Power management controls for the left and right PGA R2 Power management controls for ADC Mix/Boost (must be “on” for any PGA path to function) R7 Zero crossing timeout control R32 Automatic Level Control (ALC) for the left and right PGA R44 Input selection options for the left and right PGA R45 Volume (gain), mute, update bit, and zero crossing control for the left PGA R46 Volume (gain), mute, update bit, and zero crossing control for the right PGA Important: The R45 and R46 update bits are write-only bits. The primary intended purpose of the update bit is to enable simultaneous changes to both the left and right PGA volume values, even though these values must be written sequentially. When there is a write operation to either R45 or R46 volume settings, but the update bit is not set (value = 0), the new volume setting is stored as pending for the future, but does not go into effect. When there is a write operation to either R45 or R46 and the update bit is set (value = 1), then the new value in the register being written is immediately put into effect, and any pending value in the other PGA volume register is put into effect at the same time. Note: If the ALC automatic level control is enabled, the function of the ALC is to automatically adjust the R45 or R46 volume setting. If ALC is enabled for the left or right, or both channels, then software should avoid changing the volume setting for the affected channel or channels. The reason for this is to avoid unexpected volume changes caused by competition between the ALC and the direct software control of the volume setting. Zero-Crossing controls are implemented to suppress clicking sounds that may occur when volume setting changes take place while an audio input signal is active. When the zero crossing function is enabled (logic = 1), any volume change for the affected channel will not take place until the audio input signal passes through the zero point in its peak-to-peak swing. This prevents any instantaneous voltage change to the audio signal caused by volume setting changes. If the zero crossing function is disabled (logic = 0), volume changes take place instantly on condition of the Update Bit, but without regard to the instantaneous voltage level of the affected audio input signal. The R7 zero crossing timeout control is an additional feature to limit the amount of time that a volume change to the PGA is delayed pending a zero crossing event. If the input signal is such that there are no zero crossing events, and the timeout control is enabled (level = 1), any new volume setting to either PGA will automatically be put into effect after between 2.5 and 3.5 periods of the Slow Timer Clock (see description under “Miscellaneous Functions”). Oct 20, 2021 Page 14 of 92 Rev 3.2 NAU8822A 3.1.1 Zero Crossing Example This drawing shows in a graphical form the problem and benefits of using the zero crossing feature. There is a major audible improvement as a result of using the zero crossing feature. PGA Output with Zero Cross Enabled PGA Output with Zero Cross Disabled PGA Input Gain Change Figure 2: Zero Crossing Gain Update Operation PGA Gain R45, R46 Input Selection R44 MICN R R MICP To ADC Mix/Boost R VREF -12 dB to +35.25 dB LIN R VREF Figure 3: PGA Input Structure Simplified Schematic 3.2 Positive Microphone Input (MICP) The positive (non-inverting) microphone input (MICP) can be used separately, or as part of a differential input configuration. This input pin connects to the positive (non-inverting) terminal of the PGA amplifier under control of register R44. When the R44 associated control bit is set (logic = 1), a switch connects MICP to the PGA input. When the associated control bit is not set (logic = 0), the MICP pin is connected to a resistor of approximately 30kΩ which is tied to VREF. The purpose of the tie to VREF is to reduce any pop or click sound by keeping the DC level of the MICP pin close to VREF at all times. Note: If the MICP signal is not used differentially with MICN, the PGA gain values will be valid only if the MICN pin is terminated to a low impedance signal point. This termination should normally be an AC coupled path to signal ground. This input impedance is constant regardless of the gain value. The nominal input impedance for this input is given by the following table. Impedance for specific gain values not listed in this table can be estimated through interpolation between listed values. Oct 20, 2021 Page 15 of 92 Rev 3.2 NAU8822A Nominal Input Impedance LMICP & RMICP to non-inverting PGA input or LLIN & RLIN to non-inverting PGA input Gain (dB) -12 -9 -6 -3 0 3 6 9 12 18 30 35.25 Impedance (kΩ) 94 94 94 94 94 94 94 94 94 94 94 94 Table 1: Microphone and Line Non-Inverting Input Impedances 3.3 Negative Microphone Input (MICN) The negative(inverting) microphone input (MICN) can be used separately, or as part of a differential input configuration. This input pin connects to the negative (inverting) terminal of the PGA amplifier under control of register R44. When the R44 associated control bit is set (logic = 1), a switch connects MICP to the PGA input. When the associated control bit is not set (logic = 0), the MICN pin is connected to a resistor of approximately 30kΩ which is tied to VREF. The purpose of the tie to VREF is to reduce any pop or click sound by keeping the DC level of the MICN pin close to VREF at all times. It is important for a system designer to know that the MICN input impedance varies as a function of the selected PGA gain. This is normal and expected for a difference amplifier type topology. The nominal resistive impedance values for this input over the possible gain range are given by the following table. Impedance for specific gain values not listed in this table can be estimated through interpolation between listed values. Nominal Input Impedance LMICN or RMICN to inverting PGA input Gain (dB) -12 -9 -6 -3 0 3 6 9 12 18 30 35.25 Impedance (kΩ) 75 69 63 55 47 39 31 25 19 11 2.9 1.6 Table 2: Microphone Inverting Input Impedances System designers should also note that at the highest gain values, the input impedance is relatively low. For most inputs, the best strategy if higher gain values are needed is to use the input PGA in combination with the +20dB gain boost available on the PGA Mix/Boost stage that immediately follows the PGA output. A good guideline is to use the PGA gain for up to around 20dB of gain. If more gain than this is required and the lower input impedance of the PGA at high gains is a problem, a combination of the PGA and boost stage should be used. In this type of Oct 20, 2021 Page 16 of 92 Rev 3.2 NAU8822A combined gain configuration, it is preferred to have at least 6dB gain at the PGA input stage to benefit from the PGA low noise characteristics. 3.4 Microphone biasing The MICBIAS pin provides a low-noise microphone DC bias voltage as may be required for operation of an external microphone. This built-in feature can typically provide up to 3mA of microphone bias current. This DC bias voltage is suitable for powering either traditional ECM (electret) type microphones, or for MEMS types microphones with an independent power supply pin. Seven different bias voltages are available for optimum system performance, depending on the specific application. The microphone bias pin normally requires an external filtering capacitor as shown on the schematic in the Application section. The microphone bias function is controlled by the following registers: R1 Power control for MICBIAS feature (enabled when bit 4 = 1) R58 Optional low-noise mode and different bias voltage levels (enabled when bit 0 = 1) R44 Primary MICBIAS voltage selection The low-noise feature results in greatly reduced noise in the external MICBIAS voltage by placing a resistor of approximately 200-ohms in series with the output pin. This creates a low pass filter in conjunction with the external MICBIAS filter capacitor, but without any additional external components. The low noise feature is enabled when the mode control bit 0 in register R58 is set (level = 1) VREF Register 40, bit 0 MICBIASM Register 1, bit 4 MICBIASEN Register 44, Bits 7-8 00 Register 58, Bit 0 0 01 0 0.65 * VDDA 10 0 0.75 * VDDA 11 0 0.50 * VDDA 00 1 0.85 * VDDA 01 1 0.60 * VDDA 10 1 0.70 * VDDA 11 1 0.50 * VDDA MICBIAS R R Register 44, bits 7-8 MICBIASV Microphone Bias Voltage 0.90 * VDDA Figure 4: Microphone Bias Generator 3.5 Line/Aux Input Impedance and Variable Gain Stage Topology Except for the input PGAs, other variable gain stages are implemented similarly to the simplified schematic shown here. The gain value changes affect input impedance in the ranges detailed in the description of each type of input path. If a path is in the “not selected” condition, then the input impedance will be in a high impedance condition. If an external input pin is not used anywhere in the system, it will be coupled to a DC tie-off of approximately 30kΩ coupled to VREF. The unused input/output tie-off function is explained in more detail in the Application Information section of this document. Oct 20, 2021 Page 17 of 92 Rev 3.2 NAU8822A Gain Value Adjustment “Not Selected” Switch R Input R To Next Stage VREF -15 dB to +6.0 dB Figure 5: Variable Gain Stage Simplified Schematic The input impedance presented to these inputs depends on the input routing choices and gain values. If an input is routed to more than one internal input node, then the effective input impedance will be the parallel combination of the impedance of the multiple nodes that are used. The impedance looking into the PGA non-inverting input is constant as listed in the section discussing the microphone input PGAs. The nominal resistive input impedances looking into the ADC Mix/Boost input inputs are listed in the following table: Inputs LAUXIN & RAUXIN to L/RADC MIX/BOOST amp or LLIN & RLIN to L/RADC MIX/BOOST amp Gain (dB) Not Selected -12 -9 -6 -3 0 3 6 Impedance (kΩ) High-Z 159 113 80 57 40 28 20 Table 3: MIX/BOOST Amp Impedances The nominal resistive input impedances presented to signal pins that are directly routed to an output mixer are listed in the following table. If an input is connected to other active nodes, then this value is in parallel with the resistive input impedance of any such other node. Inputs LAUXIN & RAUXIN to bypass amp Or RAUXIN to RSPK SUBMIXER amp Gain (dB) -15 -12 -9 -6 -3 0 3 6 Impedance (kΩ) 225 159 113 80 57 40 28 20 Table 4:Bypass Amp and RSPK SUBMIXER Input Impedances Oct 20, 2021 Page 18 of 92 Rev 3.2 NAU8822A 3.6 Left and Right Line Inputs (LLIN and RLIN) A third possible input to the left or right PGA is an optionalassociated LIN left or right line level input. These inputs may be routed to the PGA non-inverting input, and/or connect directly to the ADC Mixer/Boost stage. If routed to the PGA, this signal is processed as an alternate pin for the MICPsignal. LIN may be received differentially in relation to the MICN pin and has available the same gain range as for MICP. As in the operational case of using theMICP input, the MICN input must have a low impedance path to signal ground, so that the gain values chosen in the PGA are valid. Note: It not recommended that both the LIN line input path to the PGA and the MICP path to the PGA be enabled at the same time. This will cause the differential gain to be unbalanced, and result in poor common mode rejection. Also, this will result in the LIN and MICP signals being connected together through internal chip resistors. The line input pins, may alternatively be configured to operate as a GPIO (General Purpose Input/Output) logic input pin. This intended purpose is static logic voltage level sensing to determine if a headset is present or not as part of a physical detection of a possible external headset. Only one GPIO pin at any one time can be assigned for this purpose. Registers that affect operation of the LLIN and RLIN inputs are: R2 ADC Mix/Boost power control (must be “on” for any LIN path to function) R9 GPIO selection for headset detect function R44 PGA input selection control bits If selected, all other PGA control registers (see PGA description) R47 Left line input ADC Mix/Boost volume and mute (bits 4, 5, and 6) R48 Right line input ADC Mix/Boost volume and mute (bits 4, 5, and 6) 3.7 Auxiliary inputs (LAUXIN, RAUXIN) The left and right channels each have an additional input that is separate from the programmable amplifier stage. These are the left and right auxiliary inputs, LAUXIN and RAUXIN. These inputs may be routed to either or both the associated ADC Mix/Boost stage, or the associated LCH MIX or RCH MIX output mixer. The RAUXIN input may additionally be routed to the Right Speaker Submixer in the analog output section. This path enables a sound to be output from the LSPKOUT speaker output, but without being audible anywhere else in the system. One purpose of this path is to support a traditional “beep” sound, such as from a microprocessor toggle bit. This is a historical application scenario which is now uncommon. The auxiliary inputs are affected by the following registers: ADC Mix/Boost if used (see ADC Mix/Boost section) LCH MIXER or RCH MIXER if used (see output mixer section) BEEP MIXER if used (see Beep Mixer section) Note: no power control registers affect only the auxiliary inputs The input impedance presented to these inputs depends on the input routing choices and gain values. If an input is routed to more than one internal input node, then the effective input impedance will be the parallel combination of the impedance of the multiple nodes that are used. The input impedances presented to these inputs are the same as those listed for the LLIN and RLIN inputs. 3.8 ADC Mix/Boost Stage The left and right channels each have an independent ADC Mix/Boost stage. Most analog input signals must pass through the ADC Mix/Boost stage before use anywhere else in this device. The only analog inputs that can completely bypass the ADC Mix/Boost stage are the LAUXIN and RAUXIN auxiliary inputs. The ADC mixer stage has three inputs, AUX, LIN, and PGA. The AUX input is for the associated auxiliary input, and the LIN is for the associated line input. The PGA input is an internal connection to the associated programmable gain amplifier servicing the microphone and line inputs. Oct 20, 2021 Page 19 of 92 Rev 3.2 NAU8822A All three inputs to the ADC Mix/Boost stage can be independently muted, and all three inputs have independent gain controls. The AUX and LIN inputs have an available gain range of -12dB through +6dB in 3dB steps. The PGA input path has a choice of 0dB or 20dB of gain in addition to the gain in the PGA. Registers that affect the ADC Mix/Boot stage are: R2 Power control for left and right channels R45 mute function for left channel PGA (bit 6 = 0 = muted condition) R46 mute function for right channel PGA (bit 6 = 0 = muted condition) R47 gain and mute control for left channel AUX and LIN R48 gain and mute control for right channel AUX and LIN 3.9 Input Limiter / Automatic Level Control (ALC) The input section of the NAU8822A is supported by additional combined digital and analog functionality which implement an Automatic Level Control (ALC) function. This can be very useful to automatically manage the analog input gain to optimize the signal level at the output of the programmable amplifier. The ALC can automatically amplify input signals that are too small, or decrease the amplitude if the signals are too loud. This system also helps to prevent clipping (overdrive) at the input of the ADC while maximizing the full dynamic range of the ADC. The ALC may be operated in the normal mode just described, on in a special limiter mode of operation. The limiter mode is a faster mode of operation, the primary purpose of which is to limit too-loud signals. The limiter mode of operation is described after this section which provides details on the normal mode of operation. The functional block architecture for the ALC is shown below. The ALC monitors the output of the ADC, measured after the digital decimator. The ADC output is fed into a peak detector, which updates the measured peak value whenever the absolute value of the input signal is higher than the current measured peak. The measured peak gradually decays to zero unless a new peak is detected, allowing for an accurate measurement of the signal envelope. The peak value is used by a logic algorithm to determine whether the PGA input gain should be increased, decreased, or remain the same. Rate Convert/ Decimator PGA ADC Filter Digital Decimator ALC Figure 6: ALC Block Diagram 3.9.1 Normal Mode Example Operation Immediately following is a simple example of the ALC operation. In the steady state at the beginning of the example time sequence, the PGA gain is at a steady value which results in the desired output level from the ADC. When the input signal suddenly becomes louder, the ALC reduces volume at a register determined rate and step size. This continues until the output level of the ADC is again at the desired target level. When the input signal suddenly becomes quiet, the ALC increases volume at a register determined rate and step size. When the output level from the ADC again reaches the target level, and now the input remains at a constant level, the ALC remains in a steady state. Oct 20, 2021 Page 20 of 92 Rev 3.2 NAU8822A PGA Input PGA Output PGA Gain Figure 7: ALC Normal Mode Operation 3.9.2 ALC Parameter Definitions Automatic level and volume control features are complex and have difficult to understand traditional names for many features and controls. This section defines some terms so that the explanations of this subsystem are more clear. ALC Maximum Gain: Register 32 (ALCMXGAIN) This sets the maximum allowed gain in the PGA during normal mode ALC operation. In the Limiter mode of ALC operation, the ALCMXGAIN value is not used. In the Limiter mode, the maximum gain allowed for the PGA is set equal to the pre-existing PGA gain value that was in effect at the moment in time that the Limiter mode is enabled. ALC Minimum Gain: Register 32 (ALCMNGAIN) This sets the minimum allowed gain in the PGA during all modes of ALC operation. This is useful to keep the AGC operating range close to the desired range for a given application scenario. ALC Target Value: Register 33 (ALCSL) Determines the value used by the ALC logic decisions comparing this fixed value with the output of the ADC. This value is expressed as a fraction of Full Scale (FS) output from the ADC. Depending on the logic conditions, the output value used in the comparison may be either the instantaneous value of the ADC, or otherwise a time weighted average of the ADC peak output level. ALC Attack Time: Register 34 (ALCATK)Attack time refers to how quickly a system responds to an increasing volume level that is greater than some defined threshold. Typically, attack time is much faster than decay time. In the NAU8822A, when the absolute value of the ADC output exceeds the ALC Target Value, the PGA gain will be reduced at a step size and rate determined by this parameter. When the peak ADC output is at least 1.5dB lower than the ALC Target Value, the stepped gain reduction will halt. ALC Decay Time: Register 34 (ALCDCY) Decay time refers to how quickly a system responds to a decreasing volume level. Typically, decay time is much slower than attack time. When the ADC output level is below the ALC Target value by at least 1.5dB, the PGA gain will increase at a rate determined by this parameter. The decay time constant is determined by the setting in register 34, bits 4 to 7 (ALCDCY), which sets the delay between increases in gain. In Limiter mode, the time constants are faster than in ALC mode. (See Detailed Register Map.) ALC Hold Time Register 33 (ALCHLD) Hold time refers to a duration of time when no action is taken. This is typically to avoid undesirable sounds that can happen when an ALC responds too quickly to a changing input signal. The use and amount of hold time is very application specific. In the NAU8822A, the hold time value is the duration of time that the ADC output peak value must be less than the target value before there is an actual gain increase. 3.10 ALCPeak Limiter Function Oct 20, 2021 Page 21 of 92 Rev 3.2 NAU8822A To reduce clipping and other bad audio effects, all ALC modes include a peak limiter function. This implements an emergency PGA gain reduction when the ADC output level exceeds a built-in maximum value. When the ADC output exceeds 87.5% of full scale, the ALC block ramps down the PGA gain at the maximum ALC Attack Time rate, regardless of the mode and attack rate settings, until the ADC output level has been reduced below the emergency limit threshold. This limits ADC clipping if there is a sudden increase in the input signal level. 3.10.1 ALC Normal Mode Example Using ALC Hold Time Feature Input signals with different characteristics (e.g., voice vs. music) may require different settings for this parameter for optimum performance. Increasing the ALC hold time prevents the ALC from reacting too quickly to brief periods of silence such as those that may appear in music recordings; having a shorter hold time, may be useful in voice applications where a faster reaction time helps to adjust the volume setting for speakers with different volumes. The waveform below shows the operation of the ALCHLD parameter. 16ms delay for ALCHT = 0100 PGA Input PGA Output PGA Gain Hold Delay Change Figure 8: ALC Hold Delay Change 3.11 Noise Gate (Normal Mode Only) A noise gate threshold prevents ALC amplification of noise when there is no input signal, or no signal above an expected background noise level. The noise gate is enabled by setting register 35, bit 3 (NGEN), HIGH, and the threshold level is set in register 35, bits 0 to 2 (NGTH). This does not remove noise from the signal; when there is no signal or a very quiet signal (pause) composed mostly of noise, the ALC holds the gain constant instead of amplifying the signal towards the target threshold. The NAU8822A accomplishes this by comparing the input signal level against the noise gate threshold. The noise gate only operates in conjunction with the ALC and only in Normal mode. The noise gate is asserted when: Equation 1: (Signal at ADC – PGA gain – MIC Boost gain) < NGTH (Noise Gate Threshold Level) Oct 20, 2021 Page 22 of 92 Rev 3.2 NAU8822A PGA Input PGA Output PGA Gain Figure 9: ALC Operation Without Noise Gate PGA Input Noise Gate Threshold PGA Output PGA Gain Figure 10: Noise Gate Operation Oct 20, 2021 Page 23 of 92 Rev 3.2 NAU8822A 3.12 ALC Example with ALC Min/Max Limits and Noise Gate Operation Output Level The drawing below shows the effects of ALC operation over the full scale signal range. The drawing is color coded to be more clear as follows: Blue Original Input signal (linear line from zero to maximum) Green PGA gain value over time (inverse to signal in target range) Red Output signal (held to a constant value in target range) Input < noise ALC operation range gate threshold Target ALCSL -6dB Gain (Attenuation) Clipped at ALCMNGAIN -12dB +33dB 0dB PGA Gain -12dB -39dB -6dB +6dB -39dB Input Level Register Bits Name Value 32 7-8 ALCSEL 11 32 3-5 ALCMAXGAIN 111 32 0-2 ALCMINGAIN 33 0-3 ALCLVL 35 3 NGEN 1 Noise gate enabled 35 0-2 NGTH 000 Noise gate @ -39dB 000 1011 Description ALC enabled both channels Max ALC gain @ 35.25dB Min ALC gain @ -12dB Target ALC gain @ -6dBFS Figure 11: ALC Response Envelope 3.12.1 ALC Register Map Overview ALC can be enabled for either or both the left and right ADC channels. All ALC functions and mode settings are common to the left and right channels. When either the right or left PGA is disabled, the respective PGA will remain at the most recent gain value as set by the ALC. Registers that control the ALC features and functions are: R32 R33 R34 R35 R70 R70 R71 R76 R77 Enable left/right ALC functions; set maximum gain, minimum gain ALC hold time, ALC target signal level ALC limiter mode selection, attack parameters, decay parameters Enable noise gate, noise gate parameters Selection of signal level averaging options and ALC table options Realtime readout of left channel gain value in use by ALC (same as left in stereo operation) Realtime readout of right channel gain value in use by ALC (same as right in stereo operation) Realtime readout of input signal level from averagingpeak-to-peak input signal detector Realtime readout of input signal level from averaging input signal peak detector The following table shows some of the ALC parameter values and their ranges. The complete list of settings and values is included in the Detailed Register Map. Oct 20, 2021 Page 24 of 92 Rev 3.2 NAU8822A Registe r Parameter Bits Name ALCMING AIN ALCMAXG AIN Default Programmable Range Setting Value 000 -12dB 111 35.25dB Minimum Gain of PGA 32 0-2 Maximum Gain of PGA 32 3-5 ALC Function 32 7-8 ALCEN 00 Disable d ALC Target Level 33 0-3 ALCLVL 1011 -6dBFS ALC Hold Time 33 4-7 ALCHLD 0000 0ms ALC Attack time 34 0-3 ALCATK 0010 500μs ALC Decay Time 34 4-7 ALCDCY 0011 4ms Limiter Function 34 8 ALCMODE 0 Disable d Range: -12dB to +30dB @ 6dB increments Range: -6.75dB to +35.25dB @ 6dB increments 00 = Disable 01 = Enable right channel 10 = Enable left channel 11 = Enable both channels Range: -22.5dB to -1.5dBFS @ 1.5dB increments Range: 0ms to 1024ms at 1010 and above (timesare for 0.75dB steps, and double with every step) ALCM=0 - Range: 125μs to 128ms ALCM=1 - Range: 31μs to 32ms (timesare for 0.75dB steps, and double with every step) ALCM = 0 - Range: 500μs to 512ms ALCM = 1 - Range: 125μs to 128ms (timesare for 0.75dB steps, and double with every step) 0 = ALC mode 1 = Limiter mode Table 5: Registers associated with ALC and Limiter Control 3.13 Limiter Mode When register 34, bit 8, is HIGH and ALC is enabled in register 32, bits 7-8 (ALCEN), the ALC block operates in limiter mode. In this mode, the PGA gain is constrained to be less than or equal to the PGA gain setting when the limiter mode is enabled. In addition, attack and decay times are faster in limiter mode than in normal mode as indicated by the different lookup tables for these parameters for limiter mode. The following waveform illustrates the behavior of the ALC in limiter mode in response to changes in various ALC parameters. PGA Input PGA Output PGA Gain Limiter Enabled Figure 12: ALC Limiter Mode Operation Oct 20, 2021 Page 25 of 92 Rev 3.2 NAU8822A 4 ADC Digital Block ADC Digital Filters ΣΔ ADC Digital Filter Gain 5-Band Equalizer High Pass Filter Notch Filter Digital Audio Interface The ADC digital block performs 24-bit analog-to-digital conversion and signal processing, making available a high quality audio sample stream the audio path digital interface.This block consists of a sigma-delta modulator, digital decimator/ filter, 5-band graphic equalizer, 3D effects, high pass filter, and a notch filter. The equalizer and 3D audio function block is a single resource that may be used by either the ADC or DAC, but not both at the same time. The ADC coding scheme is in twos complement format and the full-scale input level is proportional to VDDA. With a 3.3V supply voltage, the full-scale level is 1.0VRMS. Registers that affect the ADC operation are: R2 Power management enable/disable left/right ADC R5 Digital passthrough of ADC output data into DAC input R7 Sample rate indication bits (affect filter frequency scaling) R14 Oversampling, polarity inversion, and filter controls for left/right ADC R14 ADC high pass filter Audio Mode or Application Mode selection R15 Left channel ADC digital volume control and update bit function R16 Right channel ADC digital volume control and update bit function 4.1 Sampling / Oversampling Rate, Polarity Control, Digital Passthrough The audio sample rate of the ADC is determined entirely by the IMCLK internal Master Clock frequency, which is 128 times the base audio sample rate. A technique known as oversampling is used to improve noise and distortion performance of the ADC, but this does not affect the final audio sample rate. The default oversampling rate of the ADC is 64X (64 times the audio sample rate), but this can be changed to 128X for greatly improved audio performance. The higher rate increases power consumption by only approximately three milliwatts per channel, so for most applications, the improved quality is a good choice. There is almost zero increased power to also run the DACs at 128X oversampling, and the best overall quality will be achieved when both the DACs and ADCs are operated at the same oversampling rate. The polarity of either ADC output signal can be changed independently on either ADC logic output as a feature sometimes useful in management of the audio phase. This feature can help minimize any audio processing that may be otherwise required as the data are passed to other stages in the system. Digital audio passthrough allows the output of the ADCs to be directly sent to the DACs as the input signal to the DAC for DAC output. In this mode of operation, the output data from the ADCs are still available on the ADCOUT logic pin. However, any external input signal for the DAC will be ignored. The passthrough function is useful for many test and application purposes, and the DAC output may be utilized in any way that is normally supported for the DAC analog output signals. Oct 20, 2021 Page 26 of 92 Rev 3.2 NAU8822A 4.2 ADC Digital Volume Control and Update Bit Functionality The effective output audio volume of each ADC can be changed using the digital volume control feature. This processes the output of the ADC to scale the output by the amount indicated in the volume register setting. Included is a “digital mute” value which will completely mute the signal output of the ADC. The digital volume setting can range from 0dB through -127dB in 0.5dB steps. Important: The R15 and R16 update bits are write-only bits. The primary intended purpose of the update bit is to enable simultaneous changes to both the left and right ADC volume values, even though these values must be written sequentially. When there is a write operation to either R15 or R16 volume settings, but the update bit is not set (value = 0), the new volume setting is stored as pending for the future, but does not go into effect. When there is a write operation to either R15 or R16 and the update bit is set (value = 1), then the new value in the register being written is immediately put into effect, and any pending value in the other ADC volume register is put into effect at the same time. 4.3 ADC Programmable HighPass Filter Each ADC is optionally supported by a high pass filter in the digital output path. Filter operation and settings are always the same for both left and right channels. The high pass filter has two different operating modes. In the audio mode, the filter is a simple first order DC blocking filter, with a cut-off frequency of 3.7Hz. In the application specific mode, the filter is a second order audio frequency filter, with a programmable cut-off frequency. The cutoff frequency of the high pass filter is scaled depending on the sampling frequency indicated to the system by the setting in Register 7. Registers that affect operation of the programmable high pass filter are: R7 Sample rate indication to the system (affects filter coefficient internal scaling) R14 High-pass enable/disable, operating mode, and cut-off frequency The following table provides the exact cutoff frequencies with different sample rates as indicated to the system by means of Register 7. The table shows the assumed actual numerical sample rates as determined by the system clocks. Detailed response curves are provided in the Appendix section of this document. Register 14, bits 4 to 6 (HPF) 000 001 010 011 100 101 110 111 R7(SMPLR) = 101or 100 Sample Rate in kHz (FS) R7(SMPLR) = 011 or 010 R7(SMPLR) = 001 or 000 8 11.025 12 16 22.05 24 32 44.1 48 82 102 131 163 204 261 327 408 113 141 180 225 281 360 450 563 122 153 156 245 306 392 490 612 82 102 131 163 204 261 327 408 113 141 180 225 281 360 450 563 122 153 156 245 306 392 490 612 82 102 131 163 204 261 327 408 113 141 180 225 281 360 450 563 122 153 156 245 306 392 490 612 Table 6: High Pass Filter Cut-off Frequencies in Hz (with HPFAM register 14, bit 7 = 1) 4.4 Programmable Notch Filter Each ADC is optionally supported by a notch filter in the digital output path. Filter operation and settings are always the same for both left and right channels. A notch filter is useful to a very narrow band of audio frequencies in a stop band around a given center frequency. The notch filter is enabled by setting register 27, bit 7 (NFCEN), to 1. The center frequency is programmed by setting registers 27, 28, 29, and 30, bits 0 to 6 (NFA0[13:7], NFA0[6:0], NFA1[13:7], NFA1[6:0]), with two’s compliment coefficient values calculated using table __. Registers that affect operation of the notch filter are: Oct 20, 2021 Page 27 of 92 Rev 3.2 NAU8822A R27 R27 R28 R29 R30 Notch filter enable/disable Notch filter a0 coefficient high order bits and update bit Notch filter a0 coefficient low order bits and update bit Notch filter a1 coefficient high order bits and update bit Notch filter a1 coefficient low order bits and update bit Important: The register update bits are write-only bits. The update bit function is important so that all filter coefficients actively being used are changed simultaneously, even though these register values must be written sequentially. When there is a write operation to any of the filter coefficient settings, but the update bit is not set (value = 0), the value is stored as pending for the future, but does not go into effect. When there is a write operation to any coefficient register, and the update bit is set (value = 1), then the new value in the register being written is immediately put into effect, and any pending coefficient value is put into effect at the same time. Coefficient values are in the form of 2’s-complement integer values, and must be calculated based upon the desired filter properties. The mathematical operations for calculating these coefficients aredetailed in the following table. A0  2 π fb   1 − tan   2 fs     2 π fb   1 + tan   2 fs    A1 Notation Register Value (DEC) NFCA0 = -A0 x 213 − (1 + A0 )  2 π fc   x cos    fs   fc = center frequency (Hz) fb = -3dB bandwidth (Hz) fs = sample frequency (Hz) NFCA1 = -A1 x 212 Note: Values are rounded to the nearest whole number and converted to 2’s complement Table 7: Equations to calculate notch filter coefficients Oct 20, 2021 Page 28 of 92 Rev 3.2 NAU8822A 5 DAC Digital Block DAC Digital Filters Digital Audio Interface Digital Gain 5-Band Equalizer 3D Digital Peak Limiter ΣΔ DAC Digital Filter The DAC digital block uses 24-bit signal processing to generate analog audio with a 16-bit digital sample stream input. This block consists of a sigma-delta modulator, digital decimator/filter, and optional 5-band graphic equalizer/3D effects block, and a dynamic range compressor/limiter. The DAC coding scheme is in twos complement format and the full-scale output level is proportional to VDDA. With a 3.3V supply voltage, the full-scale output level is 1.0VRMS. Registers that affect the DAC operation are: R3 Power management enable/disable left/right DAC R5 Digital passthrough of ADC output data into DAC input R7 Sample rate indication bits (affect filter frequency scaling) R10 Softmute, Automute, oversampling options, polarity controls for left/right DAC R11 Left channel DAC digital volume value; update bit feature R12 Right channel DAC digital volume value; update bit feature 5.1 DAC Soft Mute Both DACs are initialized with the SoftMute function disabled, which is a shared single control bit. Softmute automatically ramps the DAC digital volume down to zero volume when enabled, and automatically ramps the DAC digital volume up to the register specified volume level for each DAC when disabled. This feature provides a tool that is useful for using the DACs without introducing pop and click sounds. 5.2 DAC AutoMute The analog output of both DACs can be automatically muted in a no signal condition. Both DACs share a single control bit for this function. When automute is enabled, the analog output of the DAC will be muted any time there are 1024 consecutive audio sample values with a zero value. If at any time there is a non-zero sample value, the DAC will be un-muted, and the 1024 count will be reinitialized to zero. 5.3 DAC Sampling / Oversampling Rate, Polarity Control, Digital Passthrough The sampling rate of the DAC is determined entirely by the frequency of its input clock and the oversampling rate setting. The oversampling rate of the DAC can be changed to 128X for improved audio performance at slightly higher power consumption. Because the additional supply current is only 1mA, in most applications the 128X oversampling is preferred for maximum audio performance. The polarity of either DAC output signal can be changed independently on either DAC analog output as a feature sometimes useful in management of the audio phase. This feature can help minimize any audio processing that may be otherwise required as the data are passed to other stages in the system. Digital audio passthrough allows the output of the ADCs to be directly sent to the DACs as the input signal to the DAC for DAC output. In this mode of operation, the external digital audio signal for the DAC will be ignored. The Oct 20, 2021 Page 29 of 92 Rev 3.2 NAU8822A passthrough function is useful for many test and application purposes, and the DAC output may be utilized in any way that is normally supported for the DAC analog output signals. 5.4 DAC Digital Volume Control and Update Bit Functionality The effective output audio volume of each DAC can be changed using the digital volume control feature. This processes the output of the DAC to scale the output by the amount indicated in the volume register setting. Included is a “digital mute” value which will completely mute the signal output of the DAC. The digital volume setting can range from 0dB through -127dB in 0.5dB steps. Important: The R11 and R12 update bits are write-only bits. The primary intended purpose of the update bit is to enable simultaneous changes to both the left and right DAC volume values, even though these values must be written sequentially. When there is a write operation to either R11 or R12 volume settings, but the update bit is not set (value = 0), the new volume setting is stored as pending for the future, but does not go into effect. When there is a write operation to either R11 or R12 and the update bit is set (value = 1), then the new value in the register being written is immediately put into effect, and any pending value in the other DAC volume register is put into effect at the same time. 5.5 DACAutomaticOutputPeak Limiter / Volume Boost Both DACs are supported by a digital output volume limiter/boost feature which can be useful to keep output levels within a desired range without any host/processor intervention. Settings are shared by both DAC channels. Registers that manage the peak limiter and volume boost functionality are: R24 Limiter enable/disable, limiter attack rate, boost decay rate R25 Limiter upper limit, limiter boost value The operation of the peak limiter is shown in the following figure. The upper signal graphs show the time varying level of the input and output signals, and the lower graph shows the gain characteristic of the limiter. When the signal level exceeds the limiter threshold value by 0.5dB or greater, the DAC digital signal level will be attenuated at a rate set by the limiter attack rate value. When the input signal level is less than the boost lower limit by 0.5dB or greater, the DAC digital volume will be increased at a rate set by the boost decay rate value. The default boost gain value is limited not to exceed 0dB (zero attenuation). DAC Input Signal Envelope DAC Output Signal Envelope Threshold -1dB 0dB -0.5dB -1dB Digital Gain Figure 13: DAC Digital Limiter Control The limiter may optionally be set to automatically boost the DAC digital signal level when the signal is more than 0.5dB below the limiter threshold. This can be useful in applications in which it is desirable to compress the signal dynamic range. This is accomplished by setting the limiter boost register bits to a value greater than zero. If the limiter is disabled, this boost value will be applied to the DAC digital output signal separate from other gain affecting values. Oct 20, 2021 Page 30 of 92 Rev 3.2 NAU8822A 5.6 5-Band Equalizer The NAU8822A includes a 5-band graphic equalizer with low distortion, low noise, and wide dynamic range. The equalizer is applied to both left and right channels. The equalizer is grouped with the 3D Stereo Enhancement signal processing function. Both functions may be assigned to support either the ADC path, or the DAC path, but not both paths simultaneously. Registers that affect operation of the 5-Band Equalizer are: R18 R18 R19 R20 R21 R22 Assign equalizer to DAC path or to ADC path (default = ADC path) Band 1 gain control and cut-off frequency Band 2 gain control, center cut-off frequency, and bandwidth Band 3 gain control, center cut-off frequency, and bandwidth Band 4 gain control, center cut-off frequency, and bandwidth Band 5 gain control and cut-off frequency Each of the five equalizer bands is independently adjustable for maximum system flexibility, and each offers up to 12dB of boost and 12dB of cut with 1dB resolution. The high and the low bands are shelving filters (high-pass and low-pass, respectively), and the middle three bands are peaking filters. Details of the register value settings are described below. Response curve examples are provided in the Appendix of this document. Register Value 00 01 10 11 1 (HighPass) Register 18 Bits 5 & 6 EQ1CF 80Hz 105Hz 135Hz 175Hz 2 (BandPass) Register 19 Bits 5 & 6 EQ2CF 230Hz 300Hz 385Hz 500Hz Equalizer Band 3 (BandPass) Register 20 Bits 5 & 6 EQ3CF 650Hz 850Hz 1.1kHz 1.4kHz 4 (BandPass) Register 21 Bits 5 & 6 EQ4CF 1.8kHz 2.4kHz 3.2kHz 4.1kHz 5 (LowPass) Register 22 Bits 5 & 6 EQ5CF 5.3kHz 6.9kHz 9.0kHz 11.7kHz Table 8: Equalizer Center/Cutoff Frequencies Register Value Binary Hex 00000 00h 00001 01h 00010 02h ---01100 0Ch 01101 17h ---11000 18h 11001 to 11111 19h to 1Fh Gain Registers +12db +11dB +10dB Increments 1dB per step 0dB -11dB Increments 1dB per step -12dB Reserved Bits 0 to 4 in registers 18 (EQ1GC) 19 (EQ2GC) 20 (EQ3GC) 21 (EQ4GC) 22 (EQ5GC) Table 9: Equalizer Gains Oct 20, 2021 Page 31 of 92 Rev 3.2 NAU8822A 5.7 3D Stereo Enhancement NAU8822A includes digital circuitry to provide flexible 3D enhancement to increase the perceived separation between the right and left channels, and has multiple options for optimum acoustic performance. The equalizer is grouped with the 3D Stereo Enhancement signal processing function. Both functions may be assigned to support either the ADC path, or the DAC path, but not both paths simultaneously. Registers that affect operation of 3D Stereo Enhancement are: R18 Assign equalizer to DAC path or to ADC path (default = ADC path) R41 3D Audio depth enhancement setting The amount of 3D enhancement applied can be programmed from the default 0% (no 3D effect) to 100% in register 41, bits 0 to 3 (DEPTH3D), as shown in Table __. Note: 3D enhancement uses increased gain to achieve its effect, so that the source signal may need to be attenuated by up to 6dB to avoid clipping. Register 41 Bits 0 to 3 3DDEPTH 3D Effect 0000 0001 0010 0% 6.7%dB 13.4%dB --- Increments 6.67% for each binary step in the input word 1110 1111 93.3% 100% Table 10: 3D Enhancement Depth 5.8 Companding Companding is used in digital communication systems to optimize signal-to-noise ratios with reduced data bit rates, using non-linear algorithms. NAU8822A supports the two main telecommunications companding standards on both the transmit and the receive sides: A-law and µ-law. The A-law algorithm is primarily used in European communication systems and the µ-law algorithm is primarily used by North America, Japan, and Australia. . Companding converts 13 bits (µ-law) or 12 bits (A-law) to 8 bits using non-linear quantization. The companded signal is an 8bit word containing sign (1-bit), exponent (3-bits) and mantissa (4-bits) Following are the data compression equations set in the ITU-T G.711 standard and implemented in the NAU8822A: 5.9 µ-law F(x) = ln( 1 + µ|x|) / ln( 1 + µ) -1 ≤ x ≤ 1 with µ=255 for the U.S. and Japan 5.10 A-law F(x) = A|x| / ( 1 + lnA) for x ≤ 1/A F(x) = ( 1 + lnA|x|) / (1 + lnA) for 1/A ≤ x ≤ 1 with A=87.6 for Europe The register affecting companding operation is: R5 Enable 8-bit mode, enable DAC companding, enable ADC companding Oct 20, 2021 Page 32 of 92 Rev 3.2 NAU8822A The companded signal is an 8-bit word consisting of a sign bit, three bits for the exponent, and four bits for the mantissa. When companding is enabled, the PCM interface must be set to an 8-bit word length. When in 8-bit mode, the Register 4 word length control (WLEN) is ignored. Companding Mode No Companding (default) ADC A-law μ-law DAC A-law μ-law Bit 4 0 Register 5 Bit3 Bit 2 0 0 1 1 1 1 Bit 1 0 1 0 1 0 Table 11: Companding Control 5.11 8-bit Word Length Writing a 1 to register 5, bit 5 (CMB8), will cause the PCM interface to use 8-bit word length for data transfer, overriding the word length configuration setting in WLEN (register 4, bits 5 and 6.). 6 Analog Outputs The NAU8822A features six different analog outputs. These are highly flexible and may be used individually or in pairs for many purposes. However, they are grouped in pairs and named for their most commonly used stereo application end uses. The following sections detail key features and functions of each type of output. Included is a description of the associated output mixers. These mixers are separate internal functional blocks that are important toward understanding all aspects of the analog output section. Important: For analog outputs depopping purpose, when powering up speakers, headphone, AUXOUTs, certain delays are generated after enabling sequence. However, the delays are created by MCLK and sample rate register. For correct operation, sending I2S signal no earlier than 250ms after speaker or headphone enabled and MCLK appearing. 6.1 Main Mixers (LMAIN MIX and RMAIN MIX) Each left and right channel is supported by an independent main mixer. This mixer combines signals from a various available signal sources internal to the device. Each mixer may also be selectively enabled/disabled as part of the power management features. The outputs of these mixers are the only signal source for the headphone outputs, and the primary signal source for the loudspeaker outputs. Each mixer can accept either or both the left and right digital to analog (DAC) outputs. Normally, the left and right DAC is mixed into the associated left and right main output mix. This additional capability to mix opposite DAC channels enables switching the left and right DAC outputs to the opposite channel, or mixing together the left and right DAC signals – all without any processor or host intervention and processing overhead. Each mixer also can also combine signals directly from the respective left or right AUX input, and from the output of the respective ADC Mix/Boost stage output. Each of these paths may be muted, or have an applied selectable gain between -15dB and +6dB in 3dB steps. Registers that affect operation of the Main Mixers are: R3 R49 R50 R51 Power control for the left and right main mixer left and right DAC cross-mixing source selection options left DAC to left main mixer source selection option right DAC to right main mixer source selection option Oct 20, 2021 Page 33 of 92 Rev 3.2 NAU8822A R50 left AUX and ADC Mix/Boost source select, and gain settings R51 right AUX and ADC Mix/Boost source select, and gain settings 6.2 Auxiliary Mixers (AUX1 MIXER and AUX2 MIXER) Each auxiliary analog output channel is supported by an independent mixer dedicated to the auxiliary output function. This mixer combines signals from a various available signal sources internal to the device. Each mixer may also be selectively enabled/disabled as part of the power management features. Unlike the main mixers, the auxiliary mixers are not identical and combine different signal sets internal to the device. These mixers in conjunction with the auxiliary outputs greatly increase the overall capabilities and flexibility of the NAU8822A. The AUX1 mixer combines together any or all of the following: Left Main Mixer output Right Main Mixer output Left DAC output Right DAC output Right ADC Mix/Boost stage output The AUX2 mixer combines together any or all of the following: Left Main Mixer output Left DAC output Left ADC Mix/Boost stage output Inverted output from AUX1 mixer stage Registers that affect operation of the Auxiliary Mixers are: R1 Power control for the left and right auxiliary mixer R56 Signal source selection for the AUX2 mixer R57 Signal source selection for the AUX1 mixer 6.3 Right Speaker Submixer The right speaker submixer serves two important functions. One is to optionally invert the output from the Right Main Mixer as an optional signal source for the right channel loudspeaker output driver. This inversion is normal and necessary in typical applications using the loudspeaker drivers. The other function of the right speaker submixer is to mix the RAUXIN input signal directly into the right channel speaker output driver. This enables the RAUXIN signal to be output on the right loudspeaker channel, but not be mixed to any other output. The traditional purpose of this path is to support an old-style beep sound, such as traditionally generated by a microprocessor output toggle bit. On the NAU8822A, this traditional function is supported by a full quality signal path that may be used for any purpose. The volume for this path has a selectable gain from -15dB through +6dB in 3dB step increments. There is no separate power management control feature for the Right Speaker Submixer. The register that affects the Right Speaker Submixer is: R43 Input mute controls, volume for RAUXIN path 6.4 Headphone Outputs (LHP and RHP) These are high quality, high current output drivers intended for driving low impedance loads such as headphones, but also suitable for a wide range of audio output applications. The only signal source for each of these outputs is from the associated left and right Main Mixer. Power for this section is provided from the VDDA pin. Each driver may be selectively enabled/disabled as part of the power management features. Each output can be individually muted, or controlled over a gain range of -57dB through +6dB in 3dB steps. Gain changes for the two headphone outputs can be coordinated through use of an update bit feature as part of the register controls. Additionally, clicks that could result from gain changes can be suppressed using an optional zero crossing feature. Oct 20, 2021 Page 34 of 92 Rev 3.2 NAU8822A Registers that affect the headphone outputs are: R2 Power management control for the left and right headphone amplifier R52 Volume, mute, update, and zero crossing controls for left headphone driver R53 Volume, mute, update, and zero crossing controls for right headphone driver Important: The R52 and R53 update bits are write-only bits. The primary intended purpose of the update bit is to enable simultaneous changes to both the left and right headphone output volume values, even though these two register values must be written sequentially. When there is a write operation to either R52 or R53 volume settings, but the update bit is not set (value = 0), the new volume setting is stored as pending for the future, but does not go into effect. When there is a write operation to either R52 or R53 and the update bit is set (value = 1), then the new value in the register being written is immediately put into effect, and any pending value in the other headphone output volume register is put into effect at the same time. Zero-Crossing controls are implemented to suppress clicking sounds that may occur when volume setting changes take place while an audio input signal is active. When the zero crossing function is enabled (logic = 1), any volume change for the affected channel will not take place until the audio input signal passes through the zero point in its peak-to-peak swing. This prevents any instantaneous voltage change to the audio signal caused by volume setting changes. If the zero crossing function is disabled (logic = 0), volume changes take place instantly on condition of the Update Bit, but without regard to the instantaneous voltage level of the affected audio input signal. 6.5 Speaker Outputs These are high current outputs suitable for driving low impedance loads, such as an 8-ohm loudspeaker. Both outputs may be used separately for a wide range of applications, however, the intended application is to use both outputs together in a BTL (Bridge-Tied-Load, and also, Balanced-Transformer-Less) configuration. In most applications, this configuration requires an additional signal inversion, which is a feature supported in the right speaker submixer block. This inversion is normal and necessary when the two speaker outputs are used together in a BTL (Bridge-Tied-Load, and also, Balanced-Transformer-Less) configuration. In this physical configuration, the RSPKOUT signal is connected to one pole of the loudspeaker, and the LSPKOUT signal is connected to the other pole of the loudspeaker. Mathematically, this creates within the loudspeaker a signal equal to (Left-Right). The desired mathematical operation for a stereo signal is to drive the speaker with (Left+Right). This is accomplished by implementing an additional inversion to the right channel signal. For most applications, best performance will be achieved when care is taken to insure that all gain and filter settings in both the left and right channel paths to the loudspeaker drivers are identical. Power for the loudspeaker outputs is supplied via the VDDSPK pin, and ground is independently provided as the VSSPK pin. This power option enables an operating voltage as high as 5Vdc and helps in a system design to prevent high current outputs from creating noise on other supply voltage rails or system grounds. VSSPK must be connected at some point in the system to VSSA, but provision of the VSSPK as a separate high current ground pin facilitates managing the flow of current to prevent “ground bounce” and other ground noise related problems. Each loudspeaker output may be selectively enabled/disabled as part of the power management features. Registers that affect the loudspeaker outputs are: R3 Power management control of LSPKOUT and RSPKOUT driver outputs R47/R48 Driver distortion mode control R49 Disable boost control for speaker outputs for VDDSPK 3.3V or lower R54 Volume (gain), mute, update bit, and zero crossing control for left speaker driver R55 Volume (gain), mute, update bit, and zero crossing control for right speaker driver Important: The R49 boost control option is set in the power-on reset condition for high voltage operation of VDDSPK. If VDDSPK is greater than 3.6Vdc, the R49 boost control bits should be remain at the power-on default settings. This insures reliable operation of the part, proper DC biasing, and optimum scaling of the signal to enable the output to achieve full scale output when VDDSPK is greater than VDDA. In the boost mode, the gain of the output stage is increased by a factor of 1.5 times the normal gain value. Important: The R54 and R55 update bits are write-only bits. The primary intended purpose of the update bit is to enable simultaneous changes to both the left and right headphone output volume values, even though these two register values must be written sequentially. When there is a write operation to either R54 or R55 volume settings, but the Oct 20, 2021 Page 35 of 92 Rev 3.2 NAU8822A update bit is not set (value = 0), the new volume setting is stored as pending for the future, but does not go into effect. When there is a write operation to either R54 or R55 and the update bit is set (value = 1), then the new value in the register being written is immediately put into effect, and any pending value in the other headphone output volume register is put into effect at the same time. Zero-Crossing controls are implemented to suppress clicking sounds that may occur when volume setting changes take place while an audio input signal is active. When the zero crossing function is enabled (logic = 1), any volume change for the affected channel will not take place until the audio input signal passes through the zero point in its peak-to-peak swing. This prevents any instantaneous voltage change to the audio signal caused by volume setting changes. If the zero crossing function is disabled (logic = 0), volume changes take place instantly on condition of the Update Bit, but without regard to the instantaneous voltage level of the affected audio input signal. The loudspeaker drivers may optionally be operated in an ultralow distortion mode. This mode may require additional external passive components to insure stable operation in some system configurations. No external components are required in normal mode speaker driver operation. Distortion performance in normal operation is excellent, and already suitable for almost every application. 6.6 Auxiliary Outputs These are high current outputs suitable for driving low impedance loads such as headphones or line level loads. Power for these outputs is supplied via the VDDSPK pin, and ground is also independently provided as the VSSPK pin. This power option enables an operating voltage as high as 5Vdc and helps in a system design to prevent high current outputs from creating noise on other supply voltage rails or system grounds. VSSPK must be connected at some point in the system to VSSA, but provision of the VSSPK as a separate high current ground pinfacilitates managing the flow of current to prevent “ground bounce” and other ground noise related problems. Each auxiliary output driver may be selectively enabled/disabled as part of the power management features.Registers that affect the auxiliary outputs are: R3 Power management control of AUXOUT1 and AUXOUT2 outputs R49 Disable boost control for AUXOUT1 and AUXOUT2 for VDDSPK 3.3Vdc or lower R56 Mute, gain control, and input selection controls for AUXOUT2 R57 Mute, gain control, and input selection controls for AUXOUT1 Important: The R49 boost control option is set in the power-on reset condition for high voltage operation of VDDSPK. If VDDSPK is greater than 3.6Vdc, the R49 boost control bits should be remain at the power-on default settings. This insures reliable operation of the part, proper DC biasing, and optimum scaling of the signal to enable the output to achieve full scale output when VDDSPK is greater than VDDA. In the boost mode, the gain of the output stage is increased by a factor of 1.5 times the normal gain value. An optional alternative function for these outputs is to provide a virtual ground for an external headphone device. This is for eliminating output capacitors for the headphone amplifier circuit in applications where this type of design is appropriate. In this type of application, the AUXOUT output is typically operated in the muted condition. In the muted condition, and with the output configured in the non-boost mode (also requiring that VDDSPK < 3.61Vdc), the AUXOUT output DC level will remain at the internal VREF level. This the same internal DC level as used by the headphone outputs. Because these DC levels are nominally the same, DC current flowing through the headphone in this mode of operation is minimized. Depending on the application, one or both of the auxiliary outputs may be used in this fashion. 7 7.1 Miscellaneous Functions Slow Timer Clock An internal Slow Timer Clock is supplied to automatically control features that happen over a relatively periods of time, or time-spans. This enables the NAU8822A to implement long time-span features without any host/processor management or intervention. Oct 20, 2021 Page 36 of 92 Rev 3.2 NAU8822A Two features are supported by the Slow Timer Clock. These arean optional automatic time out for the zero-crossing holdoff of PGA volume changes, and timing for debouncing of the mechanical jack detection feature. If either feature is required, the Slow Timer Clock must be enabled. The Slow Timer Clock is initialized in the disabled state. The Slow Timer Clock is controlled by only the following register: R7 Sample rate indication select, and Slow Timer Clock enable The Slow Timer Clock rate is derived from MCLK using an integer divider that is compensated for the sample rate as indicated by the R7 sample rate register. If the sample rate register value precisely matches the actual sample rate, then the internal Slow Timer Clock rate will be a constant value of 128ms. If the actual sample rate is, for example, 44.1kHz and the sample rate selected in R7 is 48kHz, the rate of the Slow Timer Clock will be approximately 10% slower in direct proportion of the actual vs. indicated sample rate. This scale of difference should not be important in relation to the dedicated end uses of the Slow Timer Clock. 7.2 General Purpose Inputs and Outputs (GPIO1, GPIO2, GPIO3) and Jack Detection Three pins are provided in the NAU8822A that may be used for limited logic input/output functions. GPIO1 has multiple possible functions, and may be either a logic input or logic output. GPIO2 and GPIO3 may be either line level analog inputs, or logic inputs dedicated to the purpose of jack detection. GPIO2 and GPIO3 do not have any logic output capability or function. Only one GPIO can be selected for jack detection. If a GPIO is selected for the jack detection feature, the Slow Timer Clock must be enabled. The jack detection function is automatically “debounced” such that momentary changes to the logic value of this input pin are ignored. The Slow Timer Clock is necessary for the debouncing feature. Registers that control the GPIO functionality are: R8 GPIO functional selection options R9 Jack Detection feature input selection and functional options If a GPIO is selected for the jack detection function, the required Slow Timer Clock determines the duration of the time windows for the input logic debouncing function. Because the logic level changes happen asynchronously to the Slow Timer Clock, there is inherently some variability in the timing for the jack detection function. A continuous and persistent logic change on the GPIO pin used for jack detection will result in a valid internal output signal within 2.5 to 3.5 periods of the Slow Timer Clock. Any logic change of shorter duration will be ignored. The threshold voltage for a jack detection logic-low level is no higher than 1.0Vdc. The threshold voltage for a jack detection logic-high level is no lower than 1.7Vdc. These levels will be reduced as the VDDC core logic voltage pin is reduced below 1.9Vdc. If the RLIN or LLIN input pin is used for the GPIO function, the analog signal path should be configured to be disconnected from its respective PGA input. This will not cause harm to the device, but could cause unwanted noise introduced through the PGA path. 7.3 Automated Features Linked to Jack Detection Some functionality can be automatically controlled by the jack detection logic. This feature can be used to enable the internal analog amplifier bias voltage generator, and/or enable analog output drivers automatically as a result of detecting a logic change at a GPIO pin assigned to the purpose of jack detection. This eliminates any requirement for the host/processor to perform these functions. The internal analog amplifier bias generator creates the VREF voltage reference and bias voltage used by the analog amplifiers. The ability to control it is a power management feature. This is implemented as a logical “OR” function of either the debounced internal jack detection signal, or the ABIASEN control bit in Register 1. The bias generator will be powered if either of these control signals is enabled (value = 1). Power management control of four different outputs is also optionally and selectively subject to control linked with the jack detection signal. The four outputs that can be controlled this way are the headphone driver signal pair, loudspeaker driver signal pair, AUXOUT1, and AUXOUT2. Register settings determine which outputs may be Oct 20, 2021 Page 37 of 92 Rev 3.2 NAU8822A enabled, and whether they are enabled by a logic 1 or logic 0 value. Output control is a logical “AND” operation of the jack detection controls, and of the register control bits that normally control the outputs. Both controls must be in the “ON” condition for a given output to be enabled. Registers that affect these functions are: R9 GPIO pin selection for jack detect function, jack detection enable, VREF jack enable R13 bit mapped selection of which outputs are to be enabled when jack detect is in a logic 1 state R13 bit mapped selection of which outputs are to be enabled when jack detect is in a logic 0 state 8 Clock Selection and Generation The NAU8822A has two basic clock modes that support the ADC and DAC data converters. It can accept external clocks in the slave mode, or in the master mode, it can generate the required clocks from an external reference frequency using an internal PLL (Phase Locked Loop). The internal PLL is a fractional type scaling PLL, and therefore, a very wide range of external reference frequencies can be used to create accurate audio sample rates. Separate from this ADC and DAC clock subsystem, audio data are clocked to and from the NAU8822A by means of the control logic described in the Digital Audio Interfaces section. The audio bit rate and audio sample rate for this data flow are managed by the Frame Sync (FS) and Bit Clock (BCLK) pins in the Digital Audio Interface. It is important to understand that the sampling rate for the ADC and DAC data converters is not determined by the Digital Audio Interface, and instead, this rates derived exclusively from the Internal Master Clock (IMCLK). Itis therefore a requirement that the Digital Audio Interface and data converters be operated synchronously, and that the FS, BCLK, and IMCLK signals are all derived from a common reference frequency. If these three clocks signals are not synchronous, audio quality will be reduced. The IMCLK is always exactly 256 times the sampling rate of the data converters. Also note that IMCLK should not exceed 12.288MHz under any condition. IMCLK is output from the Master Clock Prescaler. The prescaler reduces by an integer division factor the input frequency input clock. The source of this input frequency clock is either the external MCLK pin, or the output from the internal PLL Block. Registers that are used to manage and control the clock subsystem are: R1 Power management, enable control for PLL (default = disabled) R6 Master/slave mode, clock scaling, clock selection R7 Sample rate indication (scales DSP coefficients and timing – does NOT affect actual sample rate R8 MUX control and division factor for PLL output on GPIO1 R36 PLL Prescaler, Integer portion of PLL frequency multiplier R37 Highest order bits of 24-bit fraction of PLL frequency multiplier R38 Middle order bits of 24-bit fraction of PLL frequency multiplier R39 Lowest order bits of 24-bit fraction of PLL frequency multiplier In Master Mode, the IMCLK signal is used to generate FS and BCLK signals that are driven onto the FS and BCLK pins and input to the Digital Audio Interface. FS is always IMCLK/256 and the duty cycle of FS is automatically adjusted to be correct for the mode selected in the Digital Audio Interface. The frequency of BCLK may optionally be divided to optimize the bit clock rate for the application scenario. In Slave Mode, there is no connection between IMCLK and the FS and BCLK pins. In this mode, FS and BLCK are strictly input pins, and it is the responsibility of the system designer to insure that FS, BCLK, and IMCLK are synchronous and scaled appropriately for the application. Oct 20, 2021 Page 38 of 92 Rev 3.2 NAU8822A DAC ADC PLL Prescaler R36[4] Master Clock Prescaler R6[7,6,5] MCLK 0 f1 1 PLL f2 f2=R(f1) fPLL f/4 0 f/N 1 IMCLK = 256fS f/2 Master Clock Select PLL BLOCK R6[8] BCLK Output Scaler f/N f/256 R6[4,3,2] CSB / GPIO1 f/N GPIO1 MUX Control R8[2,1,0] PLL to GPIO1 Output Scaler Master / Slave Select R8[5,4] R6[0] 1 0 FS Digital Audio Interface BCLK Figure 14: PLL and Clock Select Circuit 8.1 Phase Locked Loop (PLL) General Description The PLL may be optionally used to multiply an external input clock reference frequency by a high resolution fractional number. To enable the use of the widest possible range of external reference clocks, the PLL block includes an optional divide-by-two prescaler for the input clock, a fixed divide-by-four scaler on the PLL output, and an additional programmable integer divider that is the Master Clock Prescaler. The high resolution fraction for the PLL is the ratio of the desired PLL oscillator frequency (f2), and the reference frequency at the PLL input (f1). This can be represented as R = f2/f1, with R in the form of a decimal number: xy.abcdefgh. To program the NAU8822A, this value is separated into an integer portion (“xy”), and a fractional portion, “abcdefgh”. The fractional portion of the multiplier is a value that when represented as a 24-bit binary number (stored in three 9-bit registers on the NAU8822A), very closely matches the exact desired multiplier factor. To keep the PLL within its optimal operating range, the integer portion of the decimal number (“xy”), must be any of the following decimal values: 6, 7, 8, 9, 10, 11, or 12. The input and output dividers outside of the PLL are often helpful to scale frequencies as needed to keep the “xy” value within the required range. Also, the optimum PLL oscillator frequency is in the range between 90MHz and 100MHz, and thus, it is best to keep f2 within this range. In summary, for any given design, choose:           IMCLK = desired Master Clock = (256)*(desired codec sample rate) f2 = (4)*(P)(IMCLK) or (2)*(P)(IMCLK) when PLL49MOUT bit R72[2] = 1 where P is the Master Clock Prescale integer value; optimal f2: 90MHz< f2 0.546*fs dB 0.546 fs -60 dB Group Delay 28.25 1/fs 3.7 Hz ADCHighPass Filter -3dB HighPass Filter Corner Frequency -0.5dB 10.4 Hz -0.1dB 21.6 Hz DAC Filter Passband +/- 0.035dB 0 -6dB 0.454 0.5 Passband Ripple Stopband Attenuation fs +/-0.035 Stopband 0.546 f > 0.546*fs dB fs -55 Group Delay fs dB 28 1/fs Table 20: Digital Filter Characteristics TERMINOLOGY 1. Stop Band Attenuation (dB) – the degree to which the frequency spectrum is attenuated (outside audio band) 2. Pass-band Ripple – any variation of the frequency response in the pass-band region 3. Note that this delay applies only to the filters and does not include other latencies, such as from the serial data interface Oct 20, 2021 Page 59 of 92 Rev 3.2 NAU8822A Figure 37: DAC Filter Frequency Response Figure 39: ADC Filter Frequency Response Figure 38: DAC Filter Ripple Figure 40: ADC Filter Ripple Oct 20, 2021 Page 60 of 92 Rev 3.2 NAU8822A 0 -2 d B r -4 -6 10 20 30 Hz Figure 41: ADC Highpass Filter Response, Audio Mode 0 -20 d B -40 r -60 -80 100 300 500 700 900 Hz Figure 42: ADC Highpass Filter Response, HPF enabled, FS = 48kHz 0 -20 d B -40 r -60 -80 100 300 500 700 900 Hz Figure 43: ADC Highpass Filter Response, HPF enabled, FS = 24kHz 0 -20 d B -40 r -60 -80 100 300 500 700 900 Hz Figure 44: ADC Highpass Filter Response, HPF enabled, FS = 12kHz Oct 20, 2021 Page 61 of 92 Rev 3.2 NAU8822A +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k 10k 20k Hz Figure 45: EQ Band 1 Gains for Lowest Cut-Off Frequency +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k 10k 20k Hz Figure 46: EQ Band 2 Peak Filter Gains for Lowest Cut-Off Frequency with EQ2BW = 0 +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k 10k 20k 10k 20k Hz Figure 47: EQ Band 2, EQ2BW = 0 versus EQ2BW = 1 +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k Hz Figure 48: EQ Band 3 Peak Filter Gains for Lowest Cut-Off Frequency with EQ3BW = 0 Oct 20, 2021 Page 62 of 92 Rev 3.2 NAU8822A +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k 10k 20k Hz Figure 49: EQ Band 3, EQ3BW = 0 versus EQ3BW = 1 +15 T +10 +5 d B r 0 -5 -10 -15 Figure 50: EQ Band 4 Peak Filter Gains for Lowest Cut-Off Frequencies with EQ4BW = 0 +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k 10k 20k 10k 20k Hz Figure 51: EQ Band 4, EQ4BW = 0 versus EQ4BW =1 +15 +10 +5 d B r 0 -5 -10 -15 20 50 100 200 500 1k 2k 5k Hz Figure 52: EQ Band 5 Gains for Lowest Cut-Off Frequency Oct 20, 2021 Page 63 of 92 Rev 3.2 NAU8822A 13 Appendix B: Companding Tables 13.1 µ-Law / A-Law Codes for Zero and Full Scale µ-Law Level A-Law Sign bit (D7) Chord bits (D6,D5,D4) Step bits (D3,D2,D1,D0) Sign bit (D7) Chord bits (D6,D5,D4) Step bits (D3,D2,D1,D0) + Full Scale 1 000 0000 1 010 1010 + Zero 1 111 1111 1 101 0101 - Zero 0 111 1111 0 101 0101 - Full Scale 0 000 0000 0 010 1010 Table 21: Companding Codes for Zero and Full-Scale 13.2 µ-Law / A-Law Output Codes (Digital mW) µ-Law Sample A-Law Sign bit (D7) Chord bits (D6,D5,D4) Step bits (D3,D2,D1,D0) Sign bit (D7) Chord bits (D6,D5,D4) Step bits (D3,D2,D1,D0) 1 0 001 1110 0 011 0100 2 0 000 1011 0 010 0001 3 0 000 1011 0 010 0001 4 0 001 1110 0 011 0100 5 1 001 1110 1 011 0100 6 1 000 1011 1 010 0001 7 1 000 1011 1 010 0001 8 1 001 1110 1 011 0100 Table 22: Companding Output Codes Oct 20, 2021 Page 64 of 92 Rev 3.2 NAU8822A 14 ppendix C: Control and Status Registers Register Function Name Dec Hex 0 00 SOFTWARE RESET AUX1MXEN AUX2MXEN PLLEN POWER 01 MANAGEME NT 1 MICBIASEN ABIASEN IOBUFEN REFIMP DEFAULT RHPEN LHPEN SLEEP RBSTEN 2 POWER 02 MANAGEME NT 2 LBSTEN RPGAEN LPGAEN RADCEN LADCEN DEFAULT 3 Description 8 7 6 5 4 3 2 1 0 DCBUFEN 1 Bit AUXOUT1EN POWER 03 MANAGEME NT 3 AUXOUT2EN Oct 20, 2021 Software Reset (Write any value once to reset all the registers.) Internal Tie-off Buffer In 1.5X Boost Mode Condition Enable Control 0 = Disable (DEFAULT) 1 = Enable AUX1 Mixer Enable Control 0 = Disable (DEFAULT) 1 = Enable AUX2 Mixer Enable Control 0 = Disable (DEFAULT) 1 = Enable Internal PLL Enable Control 0 = Disable (DEFAULT) 1 = Enable Microphone Bias Buffer Amplifier Output Enable Control (Pin#32) 0 = Disable (DEFAULT - MICBIAS pin in High-Z condition) 1 = Enable Internal Analog Bias Buffer Enable Control 0 = Disable (DEFAULT) 1 = Enable Internal Tie-off Buffer In Non-boost 1.0X Mode Condition Enable Control 0 = Disable (DEFAULT) 1 = Enable VREF Impedance Select (Reference used to establish VREF for internal bias buffers) 00 = off (DEFAULT - Input to internal bias buffer in High-Z floating condition) 01 = 80kΩ nominal impedance at VREF pin 10 = 300kΩ nominal impedance at VREF pin 11 = 3kΩ nominal impedance at VREF pin 0 0 0 0 0 0 0 0 0 0x000 Right Headphone Driver Enable Control (RHP analog output - Pin#29) 0 = Disable (DEFAULT - RHP pin in High-Z condition) 1 = Enable Left Headphone Driver Enable Control (LHP analog output - Pin#30) 0 = Disable (DEFAULT - LHP pin in High-Z condition) 1 = Enable Sleep Enable Control 0 = Disable (DEFAULT - Normal mode) 1 = Enable (Low-power sleep mode) Right Channel Input ADC Mix/Boost Stage Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Channel Input ADC Mix/Boost Stage Enable Control 0 = Disable (DEFAULT) 1 = Enable Right Channel input PGA Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Channel input PGA Enable Control 0 = Disable (DEFAULT) 1 = Enable Right Channel ADC Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Channel ADC Enable Control 0 = Disable (DEFAULT) 1 = Enable 0 0 0 0 0 0 0 0 0 0x000 AUXOUT1 Analog Output Enable Control (Pin#21) 0 = Disable (DEFAULT) 1 = Enable AUXOUT2 Analog Output Enable Control (Pin#22) Page 65 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex Bit Description 8 7 6 5 4 3 2 1 0 LSPKEN RSPKEN RESERVED RMIXEN LMIXEN RDACEN LDACEN DEFAULT BCLKP 0 = Disable (DEFAULT) 1 = Enable Left Speaker Output Driver Enable Control (Pin#25) 0 = Disable (DEFAULT) 1 = Enable Right Speaker Output Driver Enable Control (Pin#23) 0 = Disable (DEFAULT) 1 = Enable RESERVED Right Channel Output Main Mixer Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Channel Output Main Mixer Enable Control 0 = Disable (DEFAULT) 1 = Enable Right Channel DAC Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Channel DAC Enable Control 0 = Disable (DEFAULT) 1 = Enable 0 0 0 0 0 0 0 0 0 0x000 BCLK Phase Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted I2S Audio Data Interface Left/Right Phase Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted LRP WLEN 4 04 AUDIO INTERFACE AIFMT DACPHS ADCPHS MONO DEFAULT RESERVED CMB8 5 05 COMPANDI NG DACCM ADCCM Oct 20, 2021 PCMA & PCMB Left/Right Word Ordering Select 0 = MSB is valid on 2nd rising edge of BCLK after rising edge of FS 1 = MSB is valid on 1st rising edge of BCLK after rising edge of FS Word Length Of Audio Data Stream Select 00 = 16-bit word length 01 = 20-bit word length 10 = 24-bit word length (DEFAULT) 11 = 32-bit word length Audio Interface Data Format Select 00 = Right justified 01 = Left justified 10 = Standard I2S format (DEFAULT) 11 = PCMA or PCMB audio data format option DAC Audio Data Left-right Ordering Select 0 = Left DAC data in left phase of LRP (DEFAULT) 1 = Left DAC data in right phase of LRP (left-right reversed) ADC Audio Data Left-right Ordering Select 0 = Left ADC data is output in left phase of LRP (DEFAULT) 1 = Left ADC data is output in right phase of LRP (left-right reversed) Mono Operation Enable Control 0 = Mono mode with audio data in left phase of LRP (DEFAULT) 1 = Normal stereo mode of operation 0 0 1 0 1 0 0 0 0 0x050 RESERVED 8-bit Word Enable For Companding Mode Of Operation Enable Control 0 = Normal operation ((DEFAULT - No companding) 1 = 8-bit operation for companding mode DAC Companding Mode Select 00 = Off ((DEFAULT - Normal linear operation) 01 = RESERVED 10 = μ-law companding 11 = A-law companding ADC companding Mode Select 00 = Off ((DEFAULT - Normal linear operation) 01 = RESERVED 10 = μ-law companding 11 = A-law companding Page 66 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex DEFAULT CLKM MCLKSEL 06 CLOCK CONTROL 1 BCLKSEL RESERVED CLKIOEN DEFAULT 4WSPIEN RESERVED 7 07 CLOCK CONTROL 2 SMPLR SCLKEN DEFAULT 8 08 Description 8 7 6 5 4 3 2 1 0 ADDAP 6 Bit 0 0 0 0 0 0 0 0 0 0x000 Master Clock Source Select 0 = MCLK (Pin#11 used as master clock) 1 = Internal PLL oscillator output used as master clock (DEFAULT) Scaling Divider For Internal MCLK From Master Clock Source 000 = divide by 1 001 = divide by 1.5 010 = divide by 2 (DEFAULT) 011 = divide by 3 100 = divide by 4 101 = divide by 6 110 = divide by 8 111 = divide by 12 Scaling Divider For BCLK From MCLK Output (BCLK Pin#8, When chip is in master mode.) 000 = divide by 1 (DEFAULT) 001 = divide by 2 010 = divide by 4 011 = divide by 8 100 = divide by 16 101 = divide by 32 110 = RESERVED 111 = RESERVED RESERVED FS and BCLK Input / Output Enable Control 0 = FS and BCLK are inputs (DEFAULT - Slave mode) 1 = FS and BCLK are outputs (Master mode) 1 0 1 0 0 0 0 0 0 0x140 4-wire Control Interface Enable Control 0 = Disable (DEFAULT) 1 = Enable RESERVED Audio Data Sample Rate Indication Select (Sets up scaling for internal filter coefficients, but does not affect in any way the actual device sample rate. Should be set to value most closely matching the actual sample rate determined by 256FS internal node.) 000 = 48KHz (DEFAULT) 001 = 32KHz 010 = 24KHz 011 = 16KHz 100 = 12KHz 101 = 8KHz 110 = RESERVED 111 = RESERVED Slow Timer Clock Enable Control (Starts internal timer clock derived by dividing master clock.) 0 = Disable (DEFAULT) 1 = Enable 0 0 0 0 0 0 0 0 0 0x000 RESERVED RESERVED GPIO1PLL Scaling Divider For GPIO Clock From PLL Clock 00 = Divide by 1 (DEFAULT) 01 = Divide by 2 10 = Divide by 3 11 = Divide by 4 GPIO1PL GPIO1 Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted GPIO GPIO1SEL Oct 20, 2021 ADC Output Data Stream Directly Routed To DAC Input Data Path Enable Control 0 = Disable (DEFAULT) 1 = Enable CSB/GPIO1 Function Select 000 = Input subject to MODE Pin#18 input logic level (DEFAULT) 001 = RESERVED 010 = Temperature OK status output (Logic 0 = thermal shutdown) 011 = DAC automute condition (Logic 1 = one or both DACs automuted) Page 67 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex Bit Description 8 7 6 5 4 3 2 1 0 100 = Output divided PLL clock 101 = PLL locked condition (Logic 1 = PLL locked) 110 = Output set to logic 1 condition 111 = Output set to logic 0 condition DEFAULT JCKMIDEN JCKDEN 9 09 JACK DETECT 1 JCKDIO RESERVED DEFAULT RESERVED SOFTMT RESERVED DACOS 10 0A DAC CONTROL AUTOMT RDACPL LDACPL DEFAULT LDACVU 11 0B LEFT DAC VOLUME LDACGAIN DEFAULT RDACVU 12 RIGHT DAC 0C VOLUME RDACGAIN DEFAULT Oct 20, 2021 0 0 0 0 0 0 0 0 0 0x000 Internal Bias Amplifiers By Jack Detection Enable Control (Automatically enable internal bias amplifiers based on jack detection state sensed through GPIO pin associated to jack detection function.) Bit 7 = 1 (Enable bias amplifiers on jack at logic 0 level) Bit 8 = 1 (Enable bias amplifiers on jack at logic 1 level) Jack Detection Feature Enable Control 0 = Disable (DEFAULT) 1 = Enable Jack Detection Pin Select 00 = GPIO1 is used for jack detection feature (DEFAULT) 01 = GPIO2 is used for jack detection feature 10 = GPIO3 is used for jack detection feature 11 = RESERVED RESERVED 0 0 0 0 0 0 0 0 0 0x000 RESERVED DAC Softmute Enable Control 0 = Disable (DEFAULT) 1 = Enable RESERVED DAC Oversampling Rate Select 0 = 64x oversampling (DEFAULT) 1 = 128x oversampling DAC Automute Function Enable Control 0 = Disable (DEFAULT) 1 = Enable DAC Right Channel Output Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted DAC Left Channel Output Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted 0 0 0 0 0 0 0 0 0 0x000 DAC Left Digital Volume Update Bit (Write-only bit for synchronized L/R DAC changes) If logic = 0 on R11 write, new R11 value stored in temporary register If logic = 1 on R11 write, new R11 and pending R12 values become active DAC Left Digital Volume Control (Step size is 0.5dB.) 0000 0000 = Digital mute condition 0000 0001 = -127.0dB 0000 0010 = -126.5dB ▼ 1111 1110 = -0.5dB 1111 1111 = 0.0dB (DEFAULT) 0 1 1 1 1 1 1 1 1 0x0FF DAC Right Digital Volume Update Bit (Write-only bit for synchronized L/R DAC changes) If logic = 0 on R12 write, new R12 value stored in temporary register If logic = 1 on R12 write, new R12 and pending R11 values become active DAC Right Digital Volume Control (Step size is 0.5dB.) 0000 0000 = Digital mute condition 0000 0001 = -127.0dB 0000 0010 = -126.5dB ▼ 1111 1110 = -0.5dB 1111 1111 = 0.0dB (DEFAULT) 0 1 1 1 1 1 1 1 1 0x0FF Page 68 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex JCKDOEN1 0D JACK DETECT 2 JCKDOEN0 DEFAULT HPFEN HPFAM HPF 14 0E ADC CONTROL ADCOS RESERVED RADCPL LADCPL DEFAULT LADCVU 15 0F LEFT ADC VOLUME LADCGAIN DEFAULT RADCVU 16 10 Description 8 7 6 5 4 3 2 1 0 RESERVED 13 Bit RIGHT ADC VOLUME RADCGAIN DEFAULT 17 11 RESERVED RESERVED 18 12 EQ1 LOW CUTOFF EQM Oct 20, 2021 RESERVED Output Drivers By Jack Detection Enable Control (Automatically enable outputs drivers based on the designated jack detection input as logic = 1 condition with the jack detection feature enabled.) Bit 4 = 1 (Enable left and right headphone output drivers) Bit 5 = 1 (Enable left and right speaker output drivers) Bit 6 = 1 (Enable AUXOUT2 output driver) Bit 7 = 1 (Enable AUXOUT1 output driver) Output Drivers By Jack Detection Enable Control (Automatically enable outputs drivers based on the designated jack detection input as logic = 0 condition with the jack detection feature enabled.) Bit 0 = 1 (Enable left and right headphone output drivers) Bit 1 = 1 (Enable left and right speaker output drivers) Bit 2 = 1 (Enable AUXOUT2 output driver) Bit 3 = 1 (Enable AUXOUT1 output driver) 0 0 0 0 0 0 0 0 0 0x000 High Pass Filter For ADC Output Data Stream Enable Control 0 = Disable 1 = Enable (DEFAULT) High Pass Filter Mode Select 0 = Normal audio mode, 1st order 3.7Hz high pass filter for DC blocking (DEFAULT) 1 = Application specific mode, variable 2nd order high pass filter Application Specific Mode Cutoff Frequency Select ADC Oversampling Rate Select 0 = 64x oversampling rate (DEFAULT) 1 = 128x oversampling rate RESERVED ADC Right Channel Output Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted ADC Left Channel Output Polarity 0 = Non-inverted (DEFAULT) 1 = Inverted 1 0 0 0 0 0 0 0 0 0x100 ADC Left Digital Volume Update Bit (Write-only bit for synchronized L/R ADC changes) If logic = 0 on R15 write, new R15 value stored in temporary register If logic = 1 on R15 write, new R15 and pending R16 values become active ADC Left Digital Volume Control (Step size is 0.5dB.) 0000 0000 = Digital mute condition 0000 0001 = -127.0dB 0000 0010 = -126.5dB ▼ 1111 1110 = -0.5dB 1111 1111 = 0.0dB (DEFAULT) 0 1 1 1 1 1 1 1 1 0x0FF ADC Right Digital Volume Update Bit (Write-only bit for synchronized L/R DAC changes) If logic = 0 on R16 write, new R16 value stored in temporary register If logic = 1 on R16 write, new R16 and pending R15 values become active ADC Right Digital Volume Control (Step size is 0.5dB.) 0000 0000 = Digital mute condition 0000 0001 = -127.0dB 0000 0010 = -126.5dB ▼ 1111 1110 = -0.5dB 1111 1111 = 0.0dB (DEFAULT) 0 1 1 1 1 1 1 1 1 0x0FF RESERVED Equalizer & 3D Audio Processing Block Assignment Select 0 = Block operates on digital stream of ADC 1 = Block operates on digital stream of DAC (DEFAULT) Page 69 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex EQ1CF EQ1GC DEFAULT EQ2BW RESERVED EQ2CF 13 EQ2 - PEAK 1 EQ2GC DEFAULT EQ3BW RESERVED EQ3CF 20 14 EQ3 - PEAK 2 EQ3GC DEFAULT 21 15 Description 8 7 6 5 4 3 2 1 0 RESERVED 19 Bit EQ4 - PEAK 3 EQ4BW RESERVED Oct 20, 2021 RESERVED Equalizer Band 1 Low Pass -3dB Cut-off Frequency Select 00 = 80Hz 01 = 105Hz (DEFAULT) 10 = 135Hz 11 = 175Hz EQ Band 1 Digital Gain Control (Step size is 1dB.) 00000 = +12dB 00001 = +11dB ▼ 01100 = 0dB (DEFAULT) ▼ 11000 = -12dB 11001 = RESERVED ▼ 11110 = RESERVED 11111 = RESERVED 1 0 0 1 0 1 1 0 0 0x12C Equalizer Band 2 Bandwidth Select 0 = Narrow band characteristic (DEFAULT) 1 = Wide band characteristic RESERVED Equalizer Band 2 Center Frequency Select 00 = 230Hz 01 = 300Hz (DEFAULT) 10 = 385Hz 11 = 500Hz EQ Band 2 Digital Gain Control (Step size is 1dB.) 00000 = +12dB 00001 = +11dB ▼ 01100 = 0dB (DEFAULT) ▼ 11000 = -12dB 11001 = RESERVED ▼ 11110 = RESERVED 11111 = RESERVED 0 0 0 1 0 1 1 0 0 0x02C Equalizer Band 3 Bandwidth Select 0 = Narrow band characteristic (DEFAULT) 1 = Wide band characteristic RESERVED Equalizer Band 3 Center Frequency Select 00 = 650Hz 01 = 850Hz (DEFAULT) 10 = 1.1KHz 11 = 1.4KHz EQ Band 3 Digital Gain Control (Step size is 1dB.) 00000 = +12dB 00001 = +11dB ▼ 01100 = 0dB (DEFAULT) ▼ 11000 = -12dB 11001 = RESERVED ▼ 11110 = RESERVED 11111 = RESERVED 0 0 0 1 0 1 1 0 0 0x02C Equalizer Band 4 Bandwidth Select 0 = Narrow band characteristic (DEFAULT) 1 = Wide band characteristic RESERVED Page 70 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex EQ4GC DEFAULT RESERVED EQ5CF 16 EQ5 - HIGH CUTOFF EQ5GC DEFAULT 23 17 RESERVED RESERVED DACLIMEN DACLIMDCY 24 18 Description 8 7 6 5 4 3 2 1 0 EQ4CF 22 Bit DAC LIMITER 1 DACLIMATK Oct 20, 2021 Equalizer Band 4 Center Frequency Select 00 = 1.8KHz 01 = 2.4KHz (DEFAULT) 10 = 3.2KHz 11 = 4.1KHz EQ Band 4 Digital Gain Control (Step size is 1dB.) 00000 = +12dB 00001 = +11dB ▼ 01100 = 0dB (DEFAULT) ▼ 11000 = -12dB 11001 = RESERVED ▼ 11110 = RESERVED 11111 = RESERVED 0 0 0 1 0 1 1 0 0 0x02C RESERVED Equalizer Band 5 High Pass -3dB Cut-off Frequency Select 00 = 5.3KHz 01 = 6.9KHz (DEFAULT) 10 = 9.0KHz 11 = 11.7KHz EQ Band 5 Digital Gain Control (Step size is 1dB.) 00000 = +12dB 00001 = +11dB ▼ 01100 = 0dB (DEFAULT) ▼ 11000 = -12dB 11001 = RESERVED ▼ 11110 = RESERVED 11111 = RESERVED 0 0 0 1 0 1 1 0 0 0x02C RESERVED DAC Digital Limiter Enable Control 0 = Disable (DEFAULT) 1 = Enable DAC Limiter Decay Time (Proportional to actual DAC sample rate. Values given here are for 44.1kHz sample rate.) (Step size is double.) 0000 = 0.544ms 0001 = 1.09ms 0010 = 2.18ms 0011 = 4.36ms (DEFAULT) 0100 = 8.72ms 0101 = 17.4ms 0110 = 34.8ms 0111 = 69.6ms 1000 = 139ms 1001 = 278ms 1010 = 566ms 1011 = 1130ms 1100 = 1130ms ▼ 1111 = 1130ms DAC Limiter Attack Time (Proportional to actual DAC sample rate. Values given here are for 44.1kHz sample rate.) (Step size is double.) 0000 = 68.0us (microseconds) 0001 = 136us 0010 = 272us (DEFAULT) 0011 = 544us 0100 = 1.09ms (milliseconds) 0101 = 2.18ms 0110 = 4.36ms Page 71 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex Bit Description 8 7 6 5 4 3 2 1 0 0111 = 8.72ms 1000 = 17.4ms 1001 = 34.8ms 1010 = 69.6ms 1011 = 139ms 1100 = 139ms ▼ 1111 = 139ms DEFAULT RESERVED DACLIMTHL 25 19 DAC LIMITER 2 DACLIMBST DEFAULT 26 1A RESERVED RESERVED NFCU1 27 1B NOTCH FILTER 1 NFCEN NFCA0 DEFAULT NFCU2 28 1C NOTCH FILTER 2 RESERVED NFCA0 DEFAULT NFCU3 29 1D NOTCH FILTER 3 RESERVED DAC Limiter Threshold Related To Full Scale Output Level (0dB = full scale) 000 = -1dB (DEFAULT) 001 = -2dB 010 = -3dB 011 = -4dB 100 = -5dB 101 = -6dB 110 = -6dB 111 = -6dB DAC Limiter Maximum Automatic Gain Boost In Limiter Mode (If R24 limiter mode is disabled, specified gain value will be applied in addition to other gain values in the signal path.) (Step size is 1dB.) 0000 = 0dB (DEFAULT) 0001 = +1dB ▼ 1100 = +12dB 1101 = RESERVED 1110 = RESERVED 1111 = RESERVED 0 0 0 0 0 0 0 0 0 0x000 RESERVED Write-only Update Bit For Simultaneous Change Of All Notch Filter Parameters (Logic 0 on R27 register write causes new value to be pending an update bit event on R27, R28, R29 or R30. Logic 1 on R27 register write operation causes new R27 value and any pending value in R28, R29, or R30 to go into effect.) Notch Filter Enable Control 0 = Disable (DEFAULT) 1 = Enable Notch Filter A0 Coefficient MSB [13:7] 0 0 0 0 0 0 0 0 0 0x000 Write-only Update Bit For Simultaneous Change Of All Notch Filter Parameters (Logic 0 on R28 register write causes new value to be pending an update bit event on R27, R28, R29 or R30. Logic 1 on R28 register write operation causes new R28 value and any pending value in R27, R29, or R30 to go into effect.) RESERVED Notch Filter A0 Coefficient LSB [6:0] 0 0 0 0 0 0 0 0 0 0x000 Write-only Update Bit For Simultaneous Change Of All Notch Filter Parameters (Logic 0 on R29 register write causes new value to be pending an update bit event on R27, R28, R29 or R30. Logic 1 on R29 register write operation causes new R29 value and any pending value in R27, R28, or R30 to go into effect.) RESERVED NFCA1 DEFAULT Oct 20, 2021 0 0 0 1 1 0 0 1 0 0x032 Notch Filter A1 Coefficient MSB [13:7] 0 0 0 0 0 0 0 0 0 0x000 Page 72 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex 1E NOTCH FILTER 4 RESERVED NFCA1 DEFAULT 31 1F RESERVED RESERVED ALCEN RESERVED ALCMXGAIN 32 20 ALC CONTROL 1 ALCMNGAIN DEFAULT RESERVED ALCHT 33 21 ALC CONTROL 2 ALCSL DEFAULT 34 22 Description 8 7 6 5 4 3 2 1 0 NFCU4 30 Bit ALC CONTROL 3 Oct 20, 2021 ALCM Write-only Update Bit For Simultaneous Change Of All Notch Filter Parameters (Logic 0 on R30 register write causes new value to be pending an update bit event on R27, R28, R29 or R30. Logic 1 on R30 register write operation causes new R30 value and any pending value in R27, R28, or R29 to go into effect.) RESERVED Notch Filter A1 Coefficient LSB [6:0] 0 0 0 0 0 0 0 0 0 0x000 RESERVED Automatic Level Control Function Enable Control 00 = Disable left & right channel ALCs (DEFAULT) 01 = Enable right channel ALC only 10 = Enable left channel ALC only 11 = Enable left & right channel ALCs RESERVED Set Maximum Gain Limit For PGA Volume Changes Under ALC Control (Step size is 6dB.) 111 = +35.25dB (DEFAULT) 110 = +29.25dB 101 = +23.25dB 100 = +17.25dB 011 = +11.25dB 010 = +5.25dB 001 = -0.75dB 000 = -6.75dB Set Minimum Gain Limit For PGA Volume Changes Under ALC Control (Step size is 6dB.) 000 = -12dB (DEFAULT) 001 = -6dB 010 = 0dB 011 = +6dB 100 = +12dB 101 = +18dB 110 = +24dB 111 = +30dB 0 0 0 1 1 1 0 0 0 0x038 RESERVED Hold time Before ALC Automated Gain Increase (Step size is double.) 0000 = 0ms (DEFAULT) 0001 = 2ms 0010 = 4ms ▼ 1001 = 512ms 1010 = 1000ms 1011 = 1000ms ▼ 1111 = 1000ms ALC Target Level At ADC Output (Step size is 1.5dB.) 1111 = -1.5dB FS (Full scale) 1110 = -1.5dB FS 1101 = -3.0dB FS 1100 = -4.5dB FS 1011 = -6.0dB FS (DEFAULT) 0001 = -21.0dB FS 0000 = -22.5dB FS (Lowest possible target signal level) 0 0 0 0 0 1 0 1 1 0x00B ALC Mode Control 0 = Normal ALC operation (DEFAULT) 1 = Limiter Mode operation Page 73 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex ALCDCY ALC Decay Time (Total response time can be estimated by the total number of steps necessary to compensate for a given magnitude change in the signal. Duration per step of gain change is for 0.75dB of PGA gain. For example, a 6dB decrease in the signal would require eight ALC steps to compensate.) (Step size is double.) Normal Mode Limiter Mode 0000 = 500us 0000 = 125us 0001 = 1ms 0001 = 250us 0010 = 2ms 0010 = 500us 0011 = 4ms 0011 = 1ms (DEFAULT) 1000 = 128ms 1000 = 32ms 1001 = 256ms 1001 = 64ms 1010 = 512ms 1010 = 128ms ▼ ▼ 1111 = 512ms 1111 = 128ms ALCATK ALC Attack Time (Total response time can be estimated by the total number of steps necessary to compensate for a given magnitude change in the signal. Duration per step of gain change is for 0.75dB of PGA gain. For example, a 6dB decrease in the signal would require eight ALC steps to compensate.) (Step size is double.) Normal Mode Limiter Mode 0000 = 125us 0000 = 31us 0001 = 250us 0001 = 62us 0010 = 500us 0010 = 125us (DEFAULT) 1000 = 32ms 1000 = 8ms 1001 = 64ms 1001 = 16ms 1010 = 128ms 1010 = 32ms ▼ ▼ 1111 = 128ms 1111 = 32ms RESERVED ALCNEN 23 NOISE GATE ALCNTH DEFAULT RESERVED PLLMCLK 36 24 PLL N PLLN DEFAULT 37 25 Description 8 7 6 5 4 3 2 1 0 DEFAULT 35 Bit PLL K 1 RESERVED ALC Noise Gate Function Enable Control 0 = Disable (DEFAULT) 1 = Enable ALC Noise Gate Threshold Level (Step size is 6dB.) 000 = -39dB (DEFAULT) 001 = -45dB 010 = -51dB 011 = -57dB 100 = -63dB 101 = -69dB 110 = -75dB 111 = -81dB 0 0 0 0 0 0 0 0 0 0x000 RESERVED Pre-scale Divider For PLL Clock Input From MCLK 0 = MCLK divide by 1 (DEFAULT) 1 = MCLK divide by 2 Integer Portion Of PLL Input/Output Frequency Ratio Divider (Decimal value should be constrained to 6, 7, 8, 9, 10, 11, or 12. Default decimal value is 8.) (See text for details.) 0 0 0 0 0 1 0 0 0 0x008 RESERVED RESERVED PLLK[23:18] High Order Bits Of Fractional Portion Of PLL Input/Output Frequency Ratio Divider (See text for details.) DEFAULT Oct 20, 2021 0 0 0 1 1 0 0 1 0 0x032 0 0 0 0 0 1 1 0 0 0x00C Page 74 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex 26 PLL K 2 DEFAULT PLLK{8:0] 39 27 PLL K 3 DEFAULT 40 41 28 29 RESERVED 3D CONTROL 43 2A RESERVED 2B 0 1 1 1 0 1 0 0 1 0x0E9 RESERVED 3DDEPTH 3D Stereo Enhancement Effect Depth Select (Step size is 6.67%.) 0000 = 0.0% effect – Disable (DEFAULT) 0001 = 6.67% effect 0010 = 13.3% effect 1110 = 93.3% effect 1111 = 100% effect (MAX) 0 0 0 0 0 0 0 0 0 0x000 RESERVED RESERVED RESERVED RESERVED RMIXMUT RMIX Speaker Signal Gain Stage Output In Right Speaker Submixer Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable RSUBBYP Right Speaker Submixer Bypass Control 0 = Right speaker amplifier directly connected to RMIX speaker signal gain stage (DEFAULT) 1 = Right speaker amplifier connected to submixer output (inverts RMIX for BTL) RIGHT SPEAKER SUBMIXER DEFAULT RAUXIN Input To Right Speaker Submixer Input Gain Control (Step size is 3dB.) 000 = -15dB (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB RAUXIN Input To Right Speaker Submixer Input Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable 0 0 0 0 0 0 0 0 0 0x000 MICBIASV Microphone Bias Voltage Select (Values change slightly with R40 MISBIAS mode selection control. Open circuit voltage on MICBIAS Pin#32 is shown as follows as a fraction of the VDDA Pin#31 supply voltage.) Normal Mode Low Noise Mode 00 = 0.9x (DEFAULT) 00 = 0.85x 01 = 0.65x 01 = 0.60x 10 = 0.75x 10 = 0.70x 11 = 0.50x 11 = 0.50x RLINRPGA Right Line Input To Right PGA Positive Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable INPUT CONTROL RMICNRPGA Oct 20, 2021 Low Order Bits Of Fractional Portion Of PLL Input/Output Frequency Ratio Divider (See text for details.) RESERVED RAUXSMUT 2C 0 1 0 0 1 0 0 1 1 0x093 RESERVED RAUXRSUBG 44 Middle Order Bits Of Fractional Portion Of PLL Input/Output Frequency Ratio Divider (See text for details.) RESERVED DEFAULT 42 Description 8 7 6 5 4 3 2 1 0 PLLK[17:9] 38 Bit Right Microphone Negative Input To Right PGA Negative Input Path Enable Control 0 = Disable 1 = Enable (DEFAULT) Page 75 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex RESERVED LLINLPGA Left Line Input To Left PGA Positive Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LMICNLPGA Left Microphone Negative Input To Left PGA Negative Input Path Enable Control 0 = Disable 1 = Enable (DEFAULT) LMICPLPGA Left Microphone Positive Input To Left PGA Positive Input Path Enable Control 0 = Disable 1 = Enable (DEFAULT) LPGAU LPGAMT Left Channel PGA Mute Enable Control 0 = PGA not muted, normal operation (DEFAULT) 1 = PGA in muted condition not connected to LADC Mix/Boost stage LEFT INPUT PGA GAIN Left Channel Input PGA Volume Control (Setting becomes active when zero-crossing and/or update bit features enabled.) (Step size is 0.75dB.) 00 0000 = -12dB 00 0001 = -11.25dB ▼ 00 1111 = -0.75dB 01 0000 = 0dB (DEFAULT) 01 0001 = 0.75dB ▼ 11 1110 = +34.50dB 11 1111 = +35.25dB 0 0 0 0 1 0 0 0 0 0x010 RPGAU PGA Volume Update Bit (Write-only bit for synchronized L/R PGA changes) If logic = 0 on R46 write, new R46 value stored in temporary register If logic = 1 on R46 write, new R46 and pending R45 values become active RPGAZC Right Channel Input Zero-crossing Detection Enable Control 0 = Gain changes to PGA register happen immediately (DEFAULT) 1 = Gain changes to PGA happen pending zero-crossing logic RPGAMT Right Channel PGA Mute Enable Control 0 = PGA not muted, normal operation (DEFAULT) 1 = PGA in muted condition not connected to RADC Mix/Boost stage RIGHT INPUT PGA GAIN RPGAGAIN DEFAULT Oct 20, 2021 PGA Volume Update Bit (Write-only bit for synchronized L/R PGA changes) If logic = 0 on R45 write, new R45 value stored in temporary register If logic = 1 on R45 write, new R45 and pending R46 values become active Left Channel Input Zero-crossing Detection Enable Control 0 = Gain changes to PGA register happen immediately (DEFAULT) 1 = Gain changes to PGA happen pending zero-crossing logic DEFAULT 2E 0 0 0 1 1 0 0 1 1 0x033 LPGAZC LPGAGAIN 46 Right Microphone Positive Input To Right PGA Positive Input Path Enable Control 0 = Disable 1 = Enable (DEFAULT) RESERVED DEFAULT 2D Description 8 7 6 5 4 3 2 1 0 RMICPRPGA 45 Bit Right Channel Input PGA Volume Control (Setting becomes active when zero-crossing and/or update bit features enabled.) (Step size is 0.75dB.) 00 0000 = -12dB 00 0001 = -11.25dB ▼ 00 1111 = -0.75dB 01 0000 = 0dB (DEFAULT) 01 0001 = 0.75dB ▼ 11 1110 = +34.50dB 11 1111 = +35.25dB 0 0 0 0 1 0 0 0 0 0x010 Page 76 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex RESERVED LPGABSTGAI N 2F LEFT ADC BOOST RESERVED LAUXBSTGAI N DEFAULT RPGABST RESERVED RPGABSTGAI N 48 30 RIGHT ADC BOOST RESERVED RAUXBSTGAI N DEFAULT RESERVED LDACRMX 49 31 Description 8 7 6 5 4 3 2 1 0 LPGABST 47 Bit OUTPUT CONTROL RDACLMX AUX1BST Oct 20, 2021 LPGA Output To LADC Mix/Boost Stage Input +20dB Boost Enable Control 0 = Disable 1 = Enable (DEFAULT) RESERVED Left Line Input To LADC Mix/Boost Stage Input Gain Control (Step size is 3dB.) 000 = Path disconnected (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB RESERVED LAUXIN Input To LADC Mix/Boost Stage Input Gain Control (Step size is 3dB.) 000 = Path disconnected (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB 1 0 0 0 0 0 0 0 0 0x100 RPGA Output To RADC Mix/Boost Stage Input +20dB Boost Enable Control 0 = Disable 1 = Enable (DEFAULT) RESERVED Right Line Input To RADC Mix/Boost Stage Input Gain Control (Step size is 3dB.) 000 = Path disconnected (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB RESERVED RAUXIN Input To RADC Mix/Boost Stage Input Gain Control (Step size is 3dB.) 000 = Path disconnected (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB 1 0 0 0 0 0 0 0 0 0x100 RESERVED Left DAC Output To RMAIN MIXER Input Cross-coupling Path Enable Control 0 = Disable (DEFAULT) 1 = Enable Right DAC Output To LMAIN MIXER Input Cross-coupling Path Enable Control 0 = Disable (DEFAULT) 1 = Enable AUXOUT1 Gain +1.5X Boost Enable Control 0 = Disable (DEFAULT - Preferred setting for 3.6V and lower operation) 1 = Enable (Required setting for greater than 3.6V operation) Page 77 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex AUX2BST AUXOUT1 Gain +1.5X Boost Enable Control 0 = Disable (DEFAULT - Preferred setting for 3.6V and lower operation) 1 = Enable (Required setting for greater than 3.6V operation) SPKBST LSPKOUT & RSPKOUT Amplifier Gain +1.5X Boost Enable Control 0 = Disable (DEFAULT - Preferred setting for 3.6V and lower operation) 1 = Enable (Required setting for greater than 3.6V operation) AOUTIMP DEFAULT LAUXMXGAIN LAUXLMX 32 LEFT MIXER LBYPMXGAIN LBYPLMX LDACLMX DEFAULT RAUXMXGAIN 51 33 Description 8 7 6 5 4 3 2 1 0 TSEN 50 Bit RIGHT MIXER RAUXRMX Oct 20, 2021 Thermal Shutdown Enable Control (To protects chip from thermal destruction on overload.) 0 = Disable 1 = Enable (DEFAULT) Output Tie-off Impedance Select (Unused and disabled outputs tie to internal voltage reference to reduce pops and clicks.) 0 = Tie-off impedance value of 1KΩ (DEFAULT) 1 = Tie-off impedance value of 30KΩ 0 0 0 0 0 0 0 1 0 0x002 LAUXIN Input To LMAIN MIXER Input Gain Control (Step size is 3dB.) 000 = -15dB (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB LAUXIN Input To LMAIN MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LADC Mix/Boost Stage Output To LMAIN MIXER Input Bypass Gain Control (Step size is 3dB.) 000 = -15dB (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB LADC Mix/Boost Stage Output To LMAIN MIXER Input Bypass Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LDAC Output To LMAIN MIXER Path Enable Control 0 = Disable 1 = Enable (DEFAULT) 0 0 0 0 0 0 0 0 1 0x001 RAUXIN Input To RMAIN MIXER Input Gain Control (Step size is 3dB.) 000 = -15dB (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB RAUXIN Input To RMAIN MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable Page 78 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex RBYPMXGAIN RADC Mix/Boost Stage Output To RMAIN MIXER Input Gain Control (Step size is 3dB.) 000 = -15dB (DEFAULT) 001 = -12dB 010 = -9dB 011 = -6dB 100 = -3dB 101 = 0dB 110 = +3dB 111 = +6dB RBYPRMX RADC Mix/Boost Stage Output To RMAIN MIXER Input Bypass Path Enable Control 0 = Disable (DEFAULT) 1 = Enable RDACRMX RDAC Output To RMAIN MIXER Path Enable Control 0 = Disable 1 = Enable (DEFAULT) LHPVU LHPZC LHPMUTE 34 LHP VOLUME LHPGAIN DEFAULT RHPVU RHPZC RHPMUTE 53 35 Description 8 7 6 5 4 3 2 1 0 DEFAULT 52 Bit RHP VOLUME RHPGAIN DEFAULT Oct 20, 2021 0 0 0 0 0 0 0 0 1 0x001 Left Headphone Output Volume Update Bit (Write-only bit for synchronized changes of left and right headphone output settings.) If logic = 0 on R52 write, new R52 value stored in temporary register If logic = 1 on R52 write, new R52 and pending R53 values become active Left headphone Output Zero-crossing Detection Enable Control 0 = Gain changes to left headphone happen immediately (DEFAULT) 1 = Gain changes to left headphone pending zero-crossing logic Left headphone Output Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Headphone Output Volume Control (Setting becomes active when zero-crossing and/or update bit features enabled.) (Step size is 1dB.) 00 0000 = -57dB 00 0001 = -56dB ▼ 11 1000 = -1dB 11 1001 = 0dB (DEFAULT) 11 1010 = 1dB ▼ 11 1110 = +5dB 11 1111 = +6dB 0 0 0 1 1 1 0 0 1 0x039 Right Headphone Output Volume Update Bit (Write-only bit for synchronized changes of left and right headphone output settings.) If logic = 0 on R53 write, new R53 value stored in temporary register If logic = 1 on R53 write, new R53 and pending R52 values become active Right headphone Output Zero-crossing Detection Enable Control 0 = Gain changes to right headphone happen immediately (DEFAULT) 1 = Gain changes to right headphone pending zero-crossing logic Right headphone Output Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable Right Headphone Output Volume Control (Setting becomes active when zero-crossing and/or update bit features enabled.) (Step size is 1dB.) 00 0000 = -57dB 00 0001 = -56dB ▼ 11 1000 = -1dB 11 1001 = 0dB (DEFAULT) 11 1010 = 1dB ▼ 11 1110 = +5dB 11 1111 = +6dB 0 0 0 1 1 1 0 0 1 0x039 Page 79 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex LSPKZC LSPKMUTE 36 LSPKOUT VOLUME LSPKGAIN DEFAULT RSPKVU RSPKZC RSPKMUTE 55 37 RSPKOUT VOLUME RSPKGAIN DEFAULT RESERVED AUXOUT2MT RESERVED AUX1MIX2 56 Description 8 7 6 5 4 3 2 1 0 LSPKVU 54 Bit 38 AUX2 MIXER LADCAUX2 LMIXAUX2 LDACAUX2 DEFAULT Oct 20, 2021 Left Speaker Output Volume Update Bit (Write-only bit for synchronized changes of left and right speaker output settings.) If logic = 0 on R54 write, new R54 value stored in temporary register If logic = 1 on R54 write, new R54 and pending R55 values become active Left Speaker Output Zero-crossing Detection Enable Control 0 = Gain changes to left speaker happen immediately (DEFAULT) 1 = Gain changes to left speaker pending zero-crossing logic Left Speaker Output Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable Left Speaker Output Volume Control (Setting becomes active when zero-crossing and/or update bit features enabled.) (Step size is 1dB.) 00 0000 = -57dB 00 0001 = -56dB ▼ 11 1000 = -1dB 11 1001 = 0dB (DEFAULT) 11 1010 = 1dB ▼ 11 1110 = +5dB 11 1111 = +6dB 0 0 0 1 1 1 0 0 1 0x039 Right Speaker Output Volume Update Bit (Write-only bit for synchronized changes of left and right speaker output settings.) If logic = 0 on R55 write, new R55 value stored in temporary register If logic = 1 on R55 write, new R55 and pending R54 values become active Right Speaker Output Zero-crossing Detection Enable Control 0 = Gain changes to right speaker happen immediately (DEFAULT) 1 = Gain changes to right speaker pending zero-crossing logic Right Speaker Output Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable Right Speaker Output Volume Control (Setting becomes active when zero-crossing and/or update bit features enabled.) (Step size is 1dB.) 00 0000 = -57dB 00 0001 = -56dB ▼ 11 1000 = -1dB 11 1001 = 0dB (DEFAULT) 11 1010 = 1dB ▼ 11 1110 = +5dB 11 1111 = +6dB 0 0 0 1 1 1 0 0 1 0x039 RESERVED AUXOUT2 Output Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable RESERVED AUX1 Mixer Output To AUX2 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LADC Mix/Boost Stage Output To AUX2 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LMAIN MIXER Output To AUX2 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LDAC Output To AUX2 MIXER Input Path Enable Control 0 = Disable 1 = Enable (DEFAULT) 0 0 0 0 0 0 0 0 1 0x001 Page 80 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex AUXOUT1MT AUX1HALF LMIXAUX1 39 AUX1 MIXER LDACAUX1 RADCAUX1 RMIXAUX1 RDACAUX1 DEFAULT LPDAC LPIPBST LPADC 58 POWER 3A MANAGEME NT 4 LPSPKD MICBIASM REGVOLT IBADJ DEFAULT 59 3B LEFT TIME SLOT LTSLOT[8:0] DEFAULT PCMTSEN 60 3C Description 8 7 6 5 4 3 2 1 0 RESERVED 57 Bit MISC TRI PCM8BIT Oct 20, 2021 RESERVED AUXOUT1 Output Mute Enable Control 0 = Disable (DEFAULT) 1 = Enable AUXOUT1 -6dB Attenuation Enable Control 0 = Disable (DEFAULT) 1 = Enable LMAIN MIXER Output To AUX1 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable LDAC Output To AUX1 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable RADC Mix/Boost Stage Output To AUX1 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable RMAIN MIXER Output To AUX1 MIXER Input Path Enable Control 0 = Disable (DEFAULT) 1 = Enable RDAC Output To AUX1 MIXER Input Path Enable Control 0 = Disable 1 = Enable (DEFAULT) 0 0 0 0 0 0 0 0 1 0x001 Low Power DAC Operating Mode Enable Control (Reduce supply current by 50%.) 0 = Disable (DEFAULT) 1 = Enable Low Power ADC Mix/Boost Stage Amplifier Operating Mode Enable Control (Reduce supply current by 50%.) 0 = Disable (DEFAULT) 1 = Enable Low Power ADC Operating Mode Enable Control (Reduce supply current by 50%.) 0 = Disable (DEFAULT) 1 = Enable Low Power Speaker Amplifier Operating Mode Enable Control (Reduce supply current by 50%.) 0 = Disable (DEFAULT) 1 = Enable Low Noise Microphone Bias Operating Mode Enable Control 0 = Disable (DEFAULT - Low-Z MICBIAS output impedance) 1 = Enable (200Ohms MICBIAS output impedance) Regulator Voltage Control Power Reduction Select 00 = 1.80VDC operation (DEFAULT) 01 = 1.61VDC operation 10 = 1.40VDC operation 11 = 1.218VDC operation Master Bias Current Power Reduction Select 00 = Normal operation (DEFAULT) 01 = 25% reduced bias current 10 = 14% reduced bias current 11 = 25% reduced bias current 0 0 0 0 0 0 0 0 0 0x000 Left channel PCM Time Slot Start Count (LSB portion of total number of bit times to wait from frame sync before clocking audio channel data. LSB portion is combined with MSB from R60 to get total number of bit times to wait.) 0 0 0 0 0 0 0 0 0 0x000 PCM Mode Time Slot Function Enable Control 0 = Disable (DEFAULT) 1 = Enable Tri-state ADCOUT After Second Half Of LSB Enable Control 0 = Disable (DEFAULT) 1 = Enable PCM 8-bit Word Length Enable Control 0 = Disable (DEFAULT) Page 81 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex Bit Description 8 7 6 5 4 3 2 1 0 1 = Enable ADCOUT Output Driver Enable Control 0 = Disable (High-Z state) 1 = Enable (DEFAULT) ADCOUT Passive Resistor Pull-up Or Pull-down Enable Control 0 = Disable (DEFAULT) 1 = Enable ADCOUT Passive Resistor Pull-up Or Pull-down Select (If PUDPE = 1) 0 = Passive pull-down (DEFAULT) 1 = Passive pull-up PUDEN PUDPE PUDPS RESERVED RESERVED Right Channel PCM Time Slot Start Count (MSB portion of total number of bit times to wait from frame sync before clocking audio channel data. MSB is combined with LSB portion from R61 to get total number of bit times to wait.) Left Channel PCM Time Slot Start Count (MSB portion of total number of bit times to wait from frame sync before clocking audio channel data. MSB is combined with LSB portion from R59 to get total number of bit times to wait.) RTSLOT[9] LTSLOT[9] DEFAULT 61 0 0 0 1 0 0 0 0 0 0x020 Right Channel PCM Time Slot Start Count (LSB portion of total number of bit times to wait from frame sync before clocking audio channel data. LSB portion is combined with MSB from R60 to get total number of bit times to wait.) RIGHT TIME RTSLOT[8:0] 3D SLOT DEFAULT 0 0 0 1 0 0 0 0 0 0x020 RESERVED 62 3E DEVICE REVISION NUMBER 3F DEVICE ID# DEVICE ID# MOD DITHER 65 41 DAC DITHER ANALOG DITHER DEFAULT RESERVED HVOPU 69 45 5VOLT BIASING RESERVED HVOP DEFAULT 70 ALC ENHANCEM 46 ENT 1 0 0 x x x x x x x 0x07F (RevA SILICON) 0 0 0 0 1 1 0 1 0 Device ID (0x01A) (Equivalent to control bus address = read-only value) DAC Modulator Dither Select (To eliminate all non-random noise.) 0 0000 = Dither off 1 0010 = Nominal optimal dither (DEFAULT) 1 1111 = Maximum dither DAC Analog Output Dither Select (To eliminate all non-random noise.) 0000 = Dither off 0100 = Nominal optimal dither (DEFAULT) 1111 = Maximum dither 1 0 0 0 1 0 1 0 0 0x124 RESERVED Update Bit For HV Override Feature RESERVED Override To Automatic 3V/5V Bias Select 0 = Set internal output biasing to be optimal for 3.6VDC or lower operation 1 = Set internal output biasing to be optimal for higher than 3.6VDC operation (DEFAULT) 0 0 0 0 0 0 0 0 0 0x001 ALCTBLSEL ALC Target Level Table Select 0 = Target level table spanning -1.5dB through -22.5dB FS (DEFAULT) 1 = Optional ALC target level table spanning -6.0dB through -28.5dB FS ALCPKSEL ALC Threshold Logic Value Select 0 = Use rectified peak detector output value (DEFAULT) 1 = Use peak-to-peak detector output value ALCNGSEL Noise Gate Threshold Logic Value Select 0 = Use rectified peak detector output value (DEFAULT) 1 = Use peak-to-peak detector output value ALCGAINL DEFAULT Oct 20, 2021 Device Revision Number (For readback over control interface = read-only value) REV DEFAULT 63 RESERVED Real-time ALC Gain Value Used By Left Channel PGA 0 0 0 0 1 0 0 0 0 0x010 Page 82 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex 71 ALC 47 ENHANCEM ENT 2 48 PKLIMENA ALC Fast Peak Limiter Enable Control 0 = Enable (DEFAULT) 1 = Disable RESERVED RESERVED ALCGAINR Real-time ALC Gain Value Used By Right Channel PGA RESERVED 49 MISC CONTROLS RESERVED 4WSPIENA SPI 4-wire Force Mode Enable Control 0 = Disable (DEFAULT) 1 = Enable (Force SPI 4-wire mode regardless of state of MODE #Pin18) FSERRVAL Short Frame Sync Detection Period Value Select 00 = Trigger if frame time less than 252 MCLK edges (DEFAULT) 01 = Trigger if frame time less than 253 MCLK edges 10 = Trigger if frame time less than 254 MCLK edges 11 = Trigger if frame time less than 255 MCLK edges FSERFLSH DSP State Flush On Short Frame Sync Event 0 = Ignore short frame sync events (DEFAULT) 1 = Set DSP state to initial conditions on short frame sync event NOTCHDLY DACINMUTE PLLLOCKBP DACOSR256 DEFAULT MANINENA MANRAUX MANRLIN 74 4A INPUT TIE-OFF DIRECT MANUAL CONTROL MANRMICN MANRMICP MANLAUX MANLLIN Oct 20, 2021 0 0 0 0 1 0 0 0 0 0x010 RESERVED FSERRENA 73 Description 8 7 6 5 4 3 2 1 0 DEFAULT 72 Bit Short Frame Cycle Detection Logic Enable control 0 = Disable (DEFAULT) 1 = Enable Notch Filter Output Delay Control 0 = Delay using notch filter output 512 sample times after notch enabled (DEFAULT) 1 = Use notch filter output immediately after notch filter enabled DAC Limiter Output Mute Enable Control (when softmute is enabled.) 0 = DAC limiter output may be exactly zero during softmute (DEFAULT) 1 = DAC limiter output muted to exactly zero during softmute PLL VCO output Enable control (When PLL is not in phase locked condition.) 0 = Disable (DEFAULT) 1 = Enable DAC 256x Oversampling Rate Force Control (Best at lower sample rates) 0 = Use oversampling rate determined by Register 0x0A[3] (DEFAULT) 1 = Force 256x oversampling rate regardless of Register 0x0A[3] 0 0 0 0 0 0 0 0 0 0x000 Direct Control Over Input Tie-off Resistor Switch Manual Force General Enable Control 0 = Ignore Register 0x4A bits to control input tie-off resistor switch (DEFAULT) 1 = Use Register 0x4A bits to override automatic tie-off resistor switch RAUXIN Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for RAUXIN input is forced open (DEFAULT) 1 = Tie-off resistor switch for RAUXIN input is forced closed RLIN Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for RLIN input is forced open (DEFAULT) 1 = Tie-off resistor switch for RLIN input is forced closed RMICN Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for RMICN input is forced open (DEFAULT) 1 = Tie-off resistor switch for RMICN input is forced closed RMICP Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for RMICP input is forced open (DEFAULT) 1 = Tie-off resistor switch for RMICP input is forced closed LAUXIN Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for LAUXIN input is forced open (DEFAULT) 1 = Tie-off resistor switch for LAUXIN input is forced closed LLIN Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for LLIN input is forced open (DEFAULT) 1 = Tie-off resistor switch for LLIN input is forced closed Page 83 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex Bit Description 8 7 6 5 4 3 2 1 0 MANLMICN MANLMICP DEFAULT LMICN Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for LMICN input is forced open (DEFAULT) 1 = Tie-off resistor switch for LMICN input is forced closed LMICP Input Tie-off Resistor Switch Manual Force Enable Control (If MANUINEN = 1) 0 = Tie-off resistor switch for LMICP input is forced open (DEFAULT) 1 = Tie-off resistor switch for LMICP input is forced closed 0 0 0 0 0 0 0 0 0 0x000 76 4C AGC PEAK-TOPEAK READOUT P2PVAL (Read-only register which outputs the instantaneous value contained in the peak-to-peak amplitude register used by the ALC for signal level dependent logic. Value is highest of left or right input when both inputs are under ALC control.) 77 4D AGCPEAK DETECTOR READOUT PEAKVAL (Read-only register which outputs the instantaneous value contained in the peak detector amplitude register used by the ALC for signal level dependent logic. Value is highest of left or right input when both inputs are under ALC control.) 78 AUTOMUTE CONTROL 4E AND STATUS READOUT RESERVED RESERVED AMUTCTRL Observation Point Used By DAC Output Automute Feature Select 0 = Automute operates on data at the input to the DAC digital attenuator (DEFAULT) 1 = Automute operates on data at the DACIN input pin HVDET Status Bit Of High Voltage Detection Circuit Monitoring VDDSPK Voltage (Read-only) 0 = Voltage on VDDSPK pin measured at approximately 4.0VDC or less (DEFAULT) 1 = Voltage on VDDSPK pin measured at approximately 4.0VDC or greater NSGATE Status bit Of Noise Gate Function Logic Control (Read-only) 0 = Signal is greater than the noise gate threshold and ALC gain can change (DEFAULT) 1 = Signal is less than the noise gate threshold and ALC gain is held constant ANAMUTE Status Bit Of Analog Mute Function Of DAC Channels 0 = Non-automute condition (DEFAULT) 1 = Automute condition DIGMUTEL Status Bit Of Digital Mute Function Of left Channel DAC 0 = Digital gain value is greater than zero (DEFAULT) 1 = Digital gain is zero either by direct setting or operation of softmute function DIGMUTER DEFAULT 79 OUTPUT TIE-OFF 4F DIRECT MANUAL CONTROLS MANOUTEN Output Tie-off Resistor Switch Manual Force General Enable Control 0 = Ignore Register 0x4F bits to control input tie-off resistor/buffer switch (DEFAULT) 1 = Use Register 0x4F bits to override automatic tie-off resistor/buffer switch SHRTBUFH Bypass Switch Around 1.5x Boost Output Tie-off Buffer Amplifier Manual Force Enable Control (If MANUOUTEN = 1) 0 = Normal automatic operation of bypass switch (DEFAULT) 1 = Bypass switch in closed position when output buffer amplifier is disabled SHRTBUFL SHRTLSPK SHRTRSPK Oct 20, 2021 Status Bit Of Digital Mute Function Of Right Channel DAC 0 = Digital gain value is greater than zero (DEFAULT) 1 = Digital gain is zero either by direct setting or operation of softmute function 0 0 0 0 0 0 0 0 0 0x000 Bypass Switch Around 1.0x Non-boost Output Tie-off Buffer Amplifier Manual Force Enable Control (If MANUOUTEN = 1) 0 = Normal automatic operation of bypass switch (DEFAULT) 1 = Bypass switch in closed position when output buffer amplifier is disabled Left Speaker Output Tie-off Resistor Switch Manual Force Enable Control (If MANUOUTEN = 1) 0 = Tie-off resistor switch for LSPKOUT speaker output is forced open (DEFAULT) 1 = Tie-off resistor switch for LSPKOUT speaker output is forced closed Right Speaker Output Tie-off Resistor Switch Manual Force Enable Control (If MANUOUTEN = 1) Page 84 of 92 Rev 3.2 NAU8822A Register Function Name Dec Hex SHRTAUX2 SHRTLHP SHRTRHP DEFAULT IBTHALFI RESERVED IBT500UP IBT250DN 81 MANINBBP MANINPAD MANVREFH MANVREFM MANVREFL DEFAULT Oct 20, 2021 Description 8 7 6 5 4 3 2 1 0 SHRTAUX1 POWER REDUCTION AND OUTPUT 51 TIE-OFF DIRECT MANUAL CONTROL Bit 0 = Tie-off resistor switch for RSPKOUT speaker output is forced open (DEFAULT) 1 = Tie-off resistor switch for RSPKOUT speaker output is forced closed AUXOUT1 Output Tie-off Resistor Switch Manual Force Enable Control (If MANUOUTEN = 1) 0 = Tie-off resistor switch for AUXOUT1 output is forced open (DEFAULT) 1 = Tie-off resistor switch for AUXOUT1 output is forced closed AUXOUT2 Output Tie-off Resistor Switch Manual Force Enable Control (If MANUOUTEN = 1) 0 = Tie-off resistor switch for AUXOUT2 output is forced open (DEFAULT) 1 = Tie-off resistor switch for AUXOUT2 output is forced closed Left Headphone Output Tie-off Resistor Switch Manual Force Enable Control (If MANUOUTEN = 1) 0 = Tie-off resistor switch for LHP output is forced open (DEFAULT) 1 = Tie-off resistor switch for LHP output is forced closed Right Headphone Output Tie-off Resistor Switch Manual Force Enable Control (If MANUOUTEN = 1) 0 = Tie-off resistor switch for RHP output is forced open (DEFAULT) 1 = Tie-off resistor switch for RHP output is forced closed 0 0 0 0 0 0 0 0 0 0x000 ADC MIX/BOOST Stage Half Bias Current Enable Control (Reduce supply current by 50%.) 0 = Disable (DEFAULT) 1 = Enable RESERVED ADC MIX/BOOST Stage Increase Bias Current Enable Control (Increase supply current by 500uA.) 0 = Disable (DEFAULT) 1 = Enable ADC MIX/BOOST Stage Decrease Bias Current Enable Control (Decrease supply current by 250uA.) 0 = Disable (DEFAULT) 1 = Enable Bypass Switch Around Input Tie-off Buffer Amplifier Manual Force Enable Control 0 = Normal automatic operation of bypass switch (DEFAULT) 1 = Bypass switch in closed position when input buffer amplifier is disabled Switch To Ground Tie-off Buffer Amplifier Manual Force Enable Control 0 = Normal automatic operation of switch to ground (DEFAULT) 1 = Switch to ground in closed position when input buffer amplifier is disabled Switch For VREF 600k-Ohm Resistor To Ground Manual Force Enable Control 0 = Switch to ground controlled by REG0x01 (DEFAULT) 1 = Switch to ground in the closed position Switch For VREF 160k-Ohm Resistor To Ground Manual Force Enable Control 0 = Switch to ground controlled by REG0x01 (DEFAULT) 1 = Switch to ground in the closed position Switch For VREF 6k-Ohm Resistor To Ground Manual Force Enable Control 0 = Switch to ground controlled by REG0x01 (DEFAULT) 1 = Switch to ground in the closed position 0 0 0 0 0 0 0 0 0 0x000 Page 85 of 92 Rev 3.2 NAU8822A 15 Appendix D: Register Overview DEC HEX NAME 0 00 1 01 2 02 3 03 SOFTWARE RESET POWER MANAGEMENT 1 POWER MANAGEMENT 2 POWER MANAGEMENT 3 Bit 8 Bit 7 Bit 6 Bit5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RESET (SOFTWARE) DCBUFEN Default 000 AUX1MXEN AUX2MXEN PLLEN MICBIASEN ABIASEN IOBUFEN REFIMP 000 RHPEN NHPEN SLEEP RBSTEN LBSTEN RPGAEN LPGAEN RADCEN LADCEN 000 AUXOUT1E N AUXOUT2E N LSPKEN RSPKEN RESERVED RMIXEN LMIXEN RDACEN LDACEN 000 BCLKP LRP DACPHS ADCPHS MONO 050 0 0 ADDAP 000 CLKIOEN 140 SCLKEN 000 GENERAL AUDIO CONTROLS 4 04 AUDIO INTERFACE 5 05 COMPANDING CLOCK CONTROL 1 CLOCK CONTROL 2 6 06 7 07 8 08 GPIO 9 09 JACK DETECT 1 10 0A DAC CONTROL 11 12 LEFT DAC 0B VOLUME RIGHT DAC 0C VOLUME CLKM 0 0 0 0 0 SOFTMT JCKMIDEN 0 11 0 GPIO1PLL JCKDEN GPIO1PL JCKDIO 0 0 SMPLR 0 GPIO1SEL 000 0 0 0 0 000 DACOS AUTOMT RDACPL LDACPL 000 0FF RDACVU RDACGAIN 0FF 0 10 BCLKSEL 0 LDACGAIN HPFEN 17 ADCCM LDACVU 0E ADC CONTROL 16 DACCM MCLKSEL 0D JACK DETECT 2 0F AIFMT CMB8 0 14 15 0 4WSPIEN 13 LEFT ADC VOLUME RIGHT ADC VOLUME WLEN JCKDOEN1 HPFAM JCKDOEN0 HPF ADCOS LADCVU RADCVU 0 RADCPL 000 LADCPL 100 LADCGAIN 0FF RADCGAIN 0FF RESERVED 006 EQUALIZER 18 12 EQ1-LOW CUTOFF 19 13 20 14 21 EQM 0 EQ1CF EQ1GC 12C EQ2-PEAK 1 EQ2BW 0 EQ2CF EQ2GC 02C EQ3-PEAK 2 EQ3BW 0 EQ3CF EQ3GC 02C 15 EQ4-PEAK3 EQ4BW 0 EQ4CF EQ4GC 02C 22 16 EQ5-HIGH CUTOFF 0 0 EQ5CF EQ5GC 02C 23 17 RESERVED 000 DAC LIMITER 24 18 DAC LIMITER 1 DACLIMEN 25 19 DAC LIMITER 2 0 26 1A DACLIMDCY 0 DACLIMTHL DACLIMATK 032 DACLIMBST 000 RESERVED 000 NOTCH FILTER 27 1B NOTCH FILTER 1 NFCU1 NFCEN NFCA0[13:7] 000 28 1C NOTCH FILTER 2 NFCU2 29 1D NOTCH FILTER 3 NFCU3 0 NFCA0[6:0] 000 0 NFCA1[13:7] 000 30 1E NOTCH FILTER 4 NFCU4 0 NFCA1[6:0] 000 31 1F RESERVED 000 ALC AND NOISE GATE CONTROL 32 20 ALC CONTROL 1 33 21 ALC CONTROL 2 0 ALCHT ALCSL 00B 34 22 ALC CONTROL 3 ALCM ALCDCY ALCATK 032 Oct 20, 2021 ALCEN 0 ALCMXGAIN Page 86 of 92 ALCMNGAIN 038 Rev 3.2 NAU8822A DEC HEX NAME 35 23 Bit 8 Bit 7 Bit 6 Bit5 0 0 0 0 0 NOISE GATE Bit 4 0 Bit 3 Bit 2 Bit 1 ALCNEN Bit 0 ALCNTH Default 000 PHASE LOCKED LOOP 36 24 PLL N 0 0 0 PLLMCLK PLLN 008 37 25 PLL K 1 0 0 0 38 26 PLL K 2 PLLK[17:9] 093 39 27 PLL K 3 PLLK[8:0] 0E9 40 28 PLLK[23:18] 00C RESERVED 000 MISCELLANEOUS 41 29 3D CONTROL 42 2A 43 RIGHT SPEAKER 2B SUBMIX 2C INPUT CONTROL 45 2D 47 LEFT INPUT PGA GAIN RIGHT INPUT PGA 2E GAIN 2F 0 0 0 0 3DDEPTH 000 RESERVED 44 46 0 LEFT ADC BOOST RIGHT ADC BOOST OUTPUT CONTROL 0 0 MICBIASV 000 0 RMIXMUT RSUBBYP RLINRPGA RMICNRPG A RMICPRPG A RAUXRSUBG 0 LLINLPGA RAUXSMUT 000 LMICPLPG LMICNLPGA A 033 LPGAU LPGAZC LPGAMT LPGAGAIN 010 RPGAU RPGAZC RPGAMT RPGAGAIN 010 LPGABST 0 RPGABST 0 0 0 LPGABSTGAIN 0 30 49 31 50 32 LEFT MIXER 51 33 RIGHT MIXER 52 34 LHP VOLUME LHPVU LHPZC LHPMUTE LHPGAIN 039 53 35 RHP VOLUME RHPVU RHPZC RHPMUTE RHPGAIN 039 LSPKVU LSPKZC LSPKMUTE LSPKGAIN 039 LDACRMX LAUXMXGAIN RAUXMXGAIN RDACLMX 0 100 48 LSPKOUT VOLUME RSPKOUT VOLUME RPGABSTGAIN LAUXBSTGAIN AUX1BST RAUXBSTGAIN AUX2BST SPKBST 100 TSEN AOUTIMP 002 001 LAUXLMX LBYPMXGAIN LBYPLMX LDACLMX RAUXRMX RBYPMXGAIN RBYPRMX RDACRMX 001 54 36 55 37 RSPKVU RSPKZC RSPKMUTE 56 38 AUX2 MIXER 0 0 AUXOUT2MT 0 0 AUX1MIX>2 LADCAUX2 LMIXAUX2 LDACAUX2 001 57 39 AUX1 MIXER 0 0 AUXOUT1MT AUX1HALF LMIXAUX1 LDACAUX1 RADCAUX1 RMIXAUX1 RDACAUX1 001 LPADC LPSPKD MICBIASM RSPKGAIN 039 BEGIN NAU88C22 PROPRIETARY REGISTER SPACE 58 3A POWER MANAGEMENT 4 LPDAC LPIPBST REGVOLT IBADJ 000 PCM TIME SLOT AND ADCOUT IMPEDANCE OPTION CONTROL 59 3B LEFT TIME SLOT 60 3C MISC 61 3D RIGHT TIME SLOT LTSLOT[8:0] PCMTSEN TRI PCM8BIT PUDEN PUDPE 000 PUDPS RESERVED RTSLOT[9] LTSLOT[9] RTSLOT[8:0] 020 020 SILICON REVISION AND DEVICE ID 62 3E DEVICE REVISION RESERVED # 63 3F DEVICE ID 65 41 DAC DITHER 70 46 71 47 72 48 73 49 74 76 77 REV = 0X07F FOR REV-A 07F ID 01A MODE DITHER ANALOG DITHER ALC ALCTBLSEL ALCPKSEL ALCNGSEL ENHANCEMENTS ALC PKLIMENA RESERVED ENHANCEMENTS 110 ALCGAINL 010 ALCGAINR 010 RESERVED MISC CONTROLS TIE-OFF 4A OVERRIDES P2P DETECTOR 4C READ PEAK DETECTOR 4D READ Oct 20, 2021 4WSPIENA MANINENA FSERRVAL MANRAUX MANRLIN 000 FSERFLSH FSERRENA NOTCHDLY DACINMUTE PLLLOKBP DACOS256 000 MANRMICN MANRMICP MANLAUX MANLMICN MANLMICP 000 MANLLIN P2PVAL 000 PEAKVAL 000 Page 87 of 92 Rev 3.2 NAU8822A DEC HEX NAME 78 79 81 CONTROL AND 4E STATUS OUTPUT TIE-OFF 4F CTRL POWER/TIE-OFF 51 CTRL Oct 20, 2021 Bit 8 Bit 7 Bit 6 Bit5 RESERVED RESERVED RESERVED AMUTCTRL MANOUTEN SHRTBUFH SHRTBUFL SHRTLSPK SHRTRSPK IBTHALFI RESERVED IBT500UP IBT250DN Bit 4 HVDET MANINBBP Page 88 of 92 Bit 3 Bit 2 Bit 1 Bit 0 Default NSGATE ANAMUTE DIGMUTEL DIGMUTER 000 SHRTAUX1 SHRTAUX2 SHRTLHP SHRTRHP 000 MANINPAD MANVREFH MANVREFM MANVREFL Rev 3.2 000 NAU8822A 16 Package Dimensions 32-lead plastic QFN 32L; 5X5mm2, 0.8mm thickness, 0.5mm lead pitch Oct 20, 2021 Page 89 of 92 Rev 3.2 NAU8822A 17 Ordering Information Part Number Dimension Package Package Material NAU8822AYG 5x5 mm QFN-32 Green NAU8822A _ _ Package Material: G = Pb-free Package Package Type: Y Oct 20, 2021 = 32-Pin QFN Package Page 90 of 92 Rev 3.2 NAU8822A 18 Revision history VERSION DATE 1.0 July 29, 2009 2.0 January 25, 2011 2.1 November 08, 2011 PAGE DESCRIPTION Initial Release 88 Corrected location of low power mic bias bit from R40 to R58 PLL registers programming sequence is required to keep the IMCLK not greater than 12.288MHz. QFN32 Package diagram updated 17 39,41 2.2 November 20, 2014 52 Corrected Tsdio setup time 2.3 June 10, 2015 88 Updated package dimensions 2.4 March 2016 34 Add Important Notice 2.5 July 2016 41 Revise f1 equation from * to / 2.6 Mach, 2017 91 Added the automotive ordering part number 2.7 July 2018 55 Low pass filters added in control pins 2.8 Nov 2, 2020 38-41 2.9 Mar 23, 2021 35-36 3.0 May 5, 2021 91 3.1 May 17, 2021 43 86 3.2 Oct 20, 2021 39 65-88 PLL IMCLK Description Update Output Control register Update Speaker Outputs Description Update Auxiliary Outputs Description Update Table 13 Mode pin=0 for SPI 4 Wire removal, and 9.1 last paragraph removal Section 9.6 Appendix D Removed 96KHz/192KHz Setting Updated Register Table Format Table 23: Revision History Oct 20, 2021 Page 91 of 92 Rev 3.2 NAU8822A s Important Notice Nuvoton Products are neither intended nor warranted for usage in systems or equipment, any malfunction or failure of which may cause loss of human life, bodily injury or severe property damage. Such applications are deemed, “Insecure Usage”. Insecure usage includes, but is not limited to: equipment for surgical implementation, atomic energy control instruments, airplane or spaceship instruments, the control or operation of dynamic, brake or safety systems designed for vehicular use, traffic signal instruments, all types of safety devices, and other applications intended to support or sustain life. All Insecure Usage shall be made at customer’s risk, and in the event that third parties lay claims to Nuvoton as a result of customer’s Insecure Usage, customer shall indemnify the damages and liabilities thus incurred by Nuvoton. Oct 20, 2021 Page 92 of 92 Rev 3.2