NAU8810
Differential/Mono Audio Codec with 2-wire Interface Control Interface
emPowerAudio™
1.
GENERAL DESCRIPTION
The NAU8810 a cost effective low power wideband Monophonic audio CODEC. It is suitable for a wide range of
audio applications, including voice telephony. Supported functions include a 5-band Graphic Equalizer, Automatic
Level Control (ALC) with noise gate, PGA, standard I2S or PCM audio interface, optional PCM time slot
assignment, and a full fractional-N on-chip PLL. This device includes one differential microphone input, and
multiple variable gain control stages in the audio paths. Both a Mono headset/line-level output and a high power
differential BTL speaker driver output are provided.
The analog input path includes a PGA enabling dynamic range optimization of a wide range of input sources with
programmable gain from -12dB to +35.25dB. In addition to a digital high pass filter to remove DC offset voltages,
the ADC also features programmable voice band digital filtering. Audio data is communicated via the audio
interface that supports multiple I2S and PCM data formats. The DAC converter path includes filtering, and mixing,
programmable-gain amplifiers, and soft muting. The 2-Wire digital control interface has an independent supply
voltage to enable easy integration into multiple supply voltage systems. The NAU88U10 operates at supply
voltages from 2.5V to 3.6V, and the digital core can operate at a voltage as low as 1.71V to conserve power.
The NAU8810 is specified for operation from -40C to +85C, and is available with automotive AEC-Q100
qualification. Please refer to ordering information for AEC-Q100 compliance part number.
2.
FEATURES
24-bit signal processing linear Audio CODEC
Audio DAC: 93dB SNR and -84dB THD
Audio ADC: 91dB SNR and -79dB THD
Support variable sample rates from 8 - 48kHz
Analog I/O
Integrated programmable Microphone Amplifier
Integrated BTL Speaker Driver 1 W (8Ω / 5V)
Earphone / Speaker / Line-Output Mixing / Routing
Integrated Headset Driver 40mW (16Ω / 3.3V)
Low Noise bias supply voltage for microphone
On-chip full fractional-N PLL
Interfaces
I2S digital interface PCM time slot assignment
2-Wire serial control Interface (I2C style; /Write capable)
emPowerAudio™
Datasheet Revision 2.8
Page 1 of 102
March 1, 2017
NAU8810
Low Power, Low Voltage
Analog Supply: 2.5V to 3.6V
Digital Supply: 1.71V to 3.6V
Nominal Operating Voltage: 3.3V
Additional features
5-band Graphic Equalizer
Programmable ALC
ADC Notch Filter
Programmable High Pass Filter
Digital ADC/DAC Passthrough
Mono data output on both channels
Automotive AEC-Q100 grade 3 & TS16949 qualification, tested to a higher reliability standard
Temperature: –40C to +85C
Applications
All types of wired/wireless telephony
Security Systems
Mobile Telephone Hands-free Kits
Residential & Consumer Intercoms
MICMIC+
Microphone
Interface
Input
Mixers &
Gain
Stage
ADC
ADC Filter
Volume
Control
HPF
Notch
Filter
MOUT
DAC Filter
Volume
Control
Limiter
DAC
Output
Mixers
SPKOUT+
-1
MICBIAS
Microphone
Bias
Digital Audio Interface
I2S
PCM
Audio I/O
emPowerAudio™
Datasheet Revision 2.8
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SPKOUT-
Control IF
2-wire
Digital I/O
March 1, 2017
NAU8810
MIC+
MIC-
VREF
VDDSPK
SPKOUT -
20
19
18
17
16
PIN CONFIGURATION
3
13
MOUT
VDDD
4
12
SDIO
VSSD
5
11
SCLK
Metal
Paddle
(VSSA)
10
VSSA
MCLK
SPKOUT+
9
14
BCLK
2
8
VDDA
FS
VSSSPK
7
15
DACIN
1
6
MICBIAS
ADCOUT
3.
Figure 1: 20-Pin QFN Package
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NAU8810
4.
PIN DESCRIPTION
Pin Name
24-Pin
MICBIAS
1
VDDA
VSSA
Functionality
A/D
Pin Type
Microphone Bias
A
O
2
Analog Supply
A
I
3
Analog Ground
A
O
VDDD
4
Digital Supply
D
I
VSSD
5
Digital Ground
D
O
ADCOUT
6
Digital Audio Data Output
D
O
DACIN
7
Digital Audio Data Input
D
I
FS
8
Frame Sync
D
I/O
BCLK
9
Bit Clock
D
I/O
MCLK
10
Master Clock
D
I
SCLK
11
2-Wire Serial Clock
D
I
SDIO
12
2-Wire I/O
D
O
MOUT
13
MONO Output
A
O
SPKOUT+
14
Speaker Positive Output
A
O
VSSSPK
15
Speaker Ground
A
O
SPKOUT-
16
Speaker Negative Output
A
O
VDDSPK
17
Speaker Supply
A
I
VREF
18
Decoupling internal analog mid supply reference
A
O
MIC-
19
Microphone
Negative Input
voltage
A
I
MIC+
20
Microphone Positive Input
A
I
Table 1: Pin Description
Notes
1.
The 20-QFN package includes a bulk ground connection pad on the underside of the chip. This bulk ground
should be thermally tied to the PCB, and electrically tied to the analog ground.
2.
Unused analog input pins should be left as no-connection.
3.
Any unused digital input pin must be tied high or low as appropriate.
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MICBIASEN[4]
(0x2F)
DIGITAL AUDIO INTERFACE
VDDA
R
R
VDDA
MICROPHONE
BIAS
PMICBSTGAIN[6:4]
(0x2F) = 000
ALC
NOTCH
FILTER
DAC
PLL
(Sidetone) BYPASS
LIMITER
MCLK
CONTROL
INTERFACE
VSSA
VREF
MICBIAS
PMICPGA
ADC
VDDSPK
PMICBSTGAIN[6:4]
(0x2F)
Σ
HPF
VSSD
PGAGAIN
(0x2D)
PGAMT[6]
(0x2D)
PGABST[8]
(0x2F)
VSSD
VREF
NMICPGA[1]
(0x2C)
VSSSPK
MIC+
MIC-
BYPSPK[1]
(0x32)
DACSPK[0]
(0X32)
BYPMOUT[1]
(0x38)
DACMOUT[0]
(0x38)
SPKGAIN[5:0]
(0x36)
SPKMOUT[x:0]
(0xxx)
SPKMXEN[2]
(0x03)
Σ
Σ
MOUTMXEN[3]
(0x03)
SPKBST[2]
(0x31)
MOUTBST[3]
(0x31)
1.5X
1.0X
1.5X
1.0X
1.5X
1.0X
SPKOUT-
SPKOUT+
MOUT
5.
-12 dB to
+35.25 dB
PGAEN[2]
(0x02)
NAU8810
BLOCK DIAGRAM
SCLK
SDIO
ADCOUT
DACIN
FS
BCLK
Figure 2: NAU88U10 General Block Diagram
March 1, 2017
NAU8810
6.
Table of Contents
1.
GENERAL DESCRIPTION .................................................................................................................................1
2.
FEATURES .........................................................................................................................................................1
3.
PIN CONFIGURATION .......................................................................................................................................3
4.
PIN DESCRIPTION .............................................................................................................................................4
5.
BLOCK DIAGRAM..............................................................................................................................................5
6.
TABLE OF CONTENTS ......................................................................................................................................6
7.
LIST OF FIGURES ..............................................................................................................................................9
8.
LIST OF TABLES .............................................................................................................................................11
9.
ABSOLUTE MAXIMUM RATINGS ...................................................................................................................12
10.
OPERATING CONDITIONS ..............................................................................................................................12
11.
ELECTRICAL CHARACTERISTICS.................................................................................................................13
12.
FUNCTIONAL DESCRIPTION ..........................................................................................................................17
12.1. INPUT PATH ..............................................................................................................................................17
12.1.1. The differential microphone input (MIC- & MIC+ pins)...................................................................17
12.1.1.1.
Positive Microphone Input (MIC+) ...........................................................................................18
12.1.1.2.
Negative Microphone Input (MIC-) ...........................................................................................19
12.1.1.3. PGA Gain Control .....................................................................................................................19
12.1.2. PGA Boost / Mixer Stage ..................................................................................................................20
12.2. MICROPHONE BIASING ...........................................................................................................................21
12.3. ADC DIGITAL FILTER BLOCK .................................................................................................................22
12.3.1. Programmable High Pass Filter (HPF) ............................................................................................23
12.3.2. Programmable Notch Filter (NF) ......................................................................................................24
12.3.3. Digital ADC Gain Control ..................................................................................................................24
12.4. PROGRAMMABLE GAIN AMPLIFIER (PGA)...........................................................................................25
12.4.1. Automatic level control (ALC) ..........................................................................................................25
12.4.1.1.
Normal Mode .............................................................................................................................28
12.4.1.2. ALC Hold Time (Normal mode Only) .......................................................................................28
12.4.2. Peak Limiter Mode ............................................................................................................................29
12.4.3. Attack Time ........................................................................................................................................30
12.4.4. Decay Times ......................................................................................................................................30
12.4.5. Noise gate (normal mode only) ........................................................................................................30
12.4.6. Zero Crossing ....................................................................................................................................31
12.5. DAC DIGITAL FILTER BLOCK .................................................................................................................32
12.5.4. Hi-Fi DAC De-Emphasis and Gain Control ......................................................................................34
12.5.5. Digital DAC Output Peak Limiter .....................................................................................................34
12.5.6. Volume Boost ....................................................................................................................................34
12.5.7. 5-Band Equalizer ...............................................................................................................................35
12.6. ANALOG OUTPUTS ..................................................................................................................................36
12.6.1. Speaker Mixer Outputs .....................................................................................................................36
12.6.2. Mono Mixer Output ..........................................................................................................................37
12.6.3. Differential Output Configuration ....................................................................................................38
12.6.4. Unused Analog I/O ............................................................................................................................38
12.7. GENERAL PURPOSE CONTROL.............................................................................................................41
12.7.1. Slow Timer Clock ..............................................................................................................................41
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12.8. CLOCK GENERATION BLOCK ................................................................................................................41
12.9. CONTROL INTERFACE ............................................................................................................................45
12.9.1. 2-WIRE Serial Control (I2C Style Interface) .....................................................................................45
12.9.1.1.
2-WIRE Protocol Convention ...................................................................................................45
12.9.1.2.
2-WIRE Write Operation ...........................................................................................................46
12.9.1.3. 2-WIRE Operation ....................................................................................................................46
12.10. DIGITAL AUDIO INTERFACES.................................................................................................................47
12.10.1. Right Justified audio data ................................................................................................................48
12.10.2. Left Justified audio data ...................................................................................................................49
12.10.3. I2S audio data ....................................................................................................................................50
12.10.4. PCM audio data .................................................................................................................................51
12.10.5. PCM Time Slot audio data ................................................................................................................52
12.10.6. Companding ......................................................................................................................................53
12.11. POWER SUPPLY ......................................................................................................................................54
12.11.1. Power-On Reset ................................................................................................................................54
12.11.2. Power Related Software Considerations ........................................................................................54
12.11.3. Software Reset ..................................................................................................................................55
12.11.4. Power Up/Down Sequencing ............................................................................................................55
12.11.5. Reference Impedance (REFIMP) and Analog Bias .........................................................................57
12.11.6. Power Saving .....................................................................................................................................57
12.11.7. Estimated Supply Currents ..............................................................................................................57
13.
REGISTER DESCRIPTION ...............................................................................................................................59
13.1. SOFTWARE RESET ..................................................................................................................................61
13.2. POWER MANAGEMENT REGISTERS .....................................................................................................61
13.2.1. Power Management 1 .......................................................................................................................61
13.2.2. Power Management 2 .......................................................................................................................62
13.2.3. Power Management 3 .......................................................................................................................62
13.3. AUDIO CONTROL REGISTERS ...............................................................................................................62
13.3.1. Audio Interface Control ....................................................................................................................62
13.3.2. Audio Interface Companding Control..............................................................................................63
13.3.3. Clock Control Register .....................................................................................................................64
13.3.4. Audio Sample Rate Control Register...............................................................................................65
13.3.5. DAC Control Register .......................................................................................................................65
13.3.6. DAC Gain Control Register ..............................................................................................................66
13.3.7. ADC Control Register .......................................................................................................................66
13.3.8. ADC Gain Control Register ..............................................................................................................67
13.4. 5-BAND EQUALIZER CONTROL REGISTERS ........................................................................................68
13.5. DIGITAL TO ANALOG CONVERTER (DAC) LIMITER REGISTERS .......................................................69
13.6. NOTCH FILTER REGISTERS ...................................................................................................................70
13.7. AUTOMATIC LEVEL CONTROL REGISTER ...........................................................................................71
13.7.1. ALC1 REGISTER ...............................................................................................................................71
13.7.2. ALC2 REGISTER ...............................................................................................................................72
13.7.3. ALC3 REGISTER ...............................................................................................................................73
13.8. NOISE GAIN CONTROL REGISTER ........................................................................................................74
13.9. PHASE LOCK LOOP (PLL) REGISTERS .................................................................................................75
13.9.1. PLL Control Registers ......................................................................................................................75
13.9.2. Phase Lock Loop Control (PLL) Registers .....................................................................................75
13.10. INPUT, OUTPUT, AND MIXERS CONTROL REGISTER .........................................................................76
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13.10.1. Attenuation Control Register ...........................................................................................................76
13.10.2. Input Signal Control Register ...........................................................................................................76
13.10.3. PGA Gain Control Register ..............................................................................................................77
13.10.4. ADC Boost Control Registers ..........................................................................................................78
13.10.5. Output Register .................................................................................................................................78
13.10.6. Speaker Mixer Control Register .......................................................................................................79
13.10.7. Speaker Gain Control Register ........................................................................................................79
13.10.8. MONO Mixer Control Register ..........................................................................................................80
13.10.9. Power Management 4 .......................................................................................................................80
13.11. PCM TIME SLOT CONTROL & ADCOUT IMPEDANCE OPTION CONTROL .........................................81
13.11.1. PCM1 TIMESLOT CONTROL REGISTER .........................................................................................81
13.11.2. PCM2 TIMESLOT CONTROL REGISTER .........................................................................................81
13.12. REGISTER ID ............................................................................................................................................82
13.12.1. Device revision register ....................................................................................................................82
13.12.2. 2-WIRE ID Register ............................................................................................................................82
13.12.3. Additional ID ......................................................................................................................................82
13.13. Reserved ...................................................................................................................................................82
13.14. OUTPUT Driver Control Register ............................................................................................................83
13.15. AUTOMATIC LEVEL CONTROL ENHANCED REGISTER ......................................................................84
13.15.1. ALC1 Enhanced Register .................................................................................................................84
13.15.2. ALC Enhanced 2 Register ................................................................................................................84
13.16. MISC CONTROL REGISTER ....................................................................................................................85
13.17. Output Tie-Off REGISTER ........................................................................................................................86
13.18. AGC PEAK-TO-PEAK OUT REGISTER ...................................................................................................86
13.19. AGC PEAK OUT REGISTER.....................................................................................................................86
13.20. AUTOMUTE CONTROL AND STATUS REGISTER ................................................................................87
13.21. Output Tie-off Direct Manual Control REGISTER ..................................................................................87
14.
CONTROL INTERFACE TIMING DIAGRAM ....................................................................................................88
14.1. 2-WIRE TIMING DIAGRAM........................................................................................................................88
15.
AUDIO INTERFACE TIMING DIAGRAM ..........................................................................................................89
15.1. AUDIO INTERFACE IN SLAVE MODE ......................................................................................................89
15.2. AUDIO INTERFACE IN MASTER MODE ..................................................................................................89
15.3. PCM AUDIO INTERFACE IN SLAVE MODE (PCM Audo Data) ................................................................90
15.4. PCM AUDIO INTERFACE IN MASTER MODE (PCM Audo Data) ............................................................90
15.5. PCM AUDIO INTERFACE IN SLAVE MODE (PCM Time Slot Mode ) .......................................................91
91
15.6. PCM AUDIO INTERFACE IN MASTER MODE (PCM Time Slot Mode ) ...................................................91
15.7. System Clock (MCLK) Timing Diagram ......................................................................................................92
15.8. µ-LAW ENCODE DECODE CHARACTERISTICS ....................................................................................93
15.9. A-LAW ENCODE DECODE CHARACTERISTICS....................................................................................94
15.10. µ-LAW / A-LAW CODES FOR ZERO AND FULL SCALE ........................................................................95
15.11. µ-LAW / A-LAW OUTPUT CODES (DIGITAL MW)...................................................................................95
16.
DIGITAL FILTER CHARACTERISTICS ...........................................................................................................96
17.
TYPICAL APPLICATION ..................................................................................................................................98
18.
PACKAGE SPECIFICATION ............................................................................................................................99
19.
ORDERING INFORMATION ...........................................................................................................................100
20.
VERSION HISTORY .......................................................................................................................................101
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NAU8810
7.
List of Figures
Figure 1: 20-Pin QFN Package .....................................................................................................................................3
Figure 2: NAU88U10 General Block Diagram ...............................................................................................................5
Figure 3: Input PGA Circuit Block Diagram .................................................................................................................18
Figure 4: Boost Stage Block Diagram .........................................................................................................................20
Figure 5: Microphone Bias Schematic .........................................................................................................................21
Figure 6: ADC Digital Filter Path Block Diagram .........................................................................................................22
Figure 7: ALC Block Diagram ......................................................................................................................................25
Figure 8: ALC Response Graph ..................................................................................................................................26
Figure 9: ALC Normal Mode Operation .......................................................................................................................28
Figure 10: ALC Hold Time ...........................................................................................................................................29
Figure 11: ALC Limiter Mode Operations ....................................................................................................................29
Figure 12: ALC Operation with Noise Gate disabled ...................................................................................................30
Figure 13: ALC Operation with Noise Gate Enabled ...................................................................................................31
Figure 14: DAC Digital Filter Path ...............................................................................................................................32
Figure 15: DAC Digital Limiter Control ........................................................................................................................34
Figure 16: Speaker and MONO Analogue Outputs [To Update ? output from Auxilliary Amplifier] .............................36
Figure 17: Tie-off Options for the Speaker and MONO output Pins ............................................................................39
Figure 18: PLL and Clock Select Circuit ......................................................................................................................41
Figure 19: Valid START Condition ..............................................................................................................................45
Figure 20: Valid Acknowledge .....................................................................................................................................45
Figure 21: Valid STOP Condition ................................................................................................................................45
Figure 22: Slave Address Byte, Control Address Byte, and Data Byte .......................................................................46
Figure 23: Byte Write Sequence .................................................................................................................................46
Figure 24: 2-Wire Read Sequence ..............................................................................................................................47
Figure 25: Right Justified Audio Interface (Normal Mode) ...........................................................................................48
Figure 26: Right Justified Audio Interface (Special mode) ..........................................................................................49
Figure 27: Left Justified Audio Interface (Normal Mode) .............................................................................................49
Figure 28: Left Justified Audio Interface (Special mode) .............................................................................................50
Figure 29: I2S Audio Interface (Normal Mode) ............................................................................................................50
Figure 30: I2S Audio Interface (Special mode)............................................................................................................51
Figure 31: PCM Mode Audio Interface (Normal Mode) ...............................................................................................51
Figure 32: PCM Mode Audio Interface (Special mode) ...............................................................................................52
Figure 33: PCM Time Slot Mode (Time slot = 0) (Normal Mode) ................................................................................52
Figure 34: PCM Time Slot Mode (Time slot = 0) (Special mode) ................................................................................53
Figure 35: The Programmable ADCOUT Pin ..............................................................................................................81
Figure 36: 2-Wire Timing Diagram ..............................................................................................................................88
Figure 37: Audio Interface Slave Mode Timing Diagram .............................................................................................89
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Figure 38: Audio Interface in Master Mode Timing Diagram .......................................................................................89
Figure 39: PCM Audio Interface Slave Mode Timing Diagram ....................................................................................90
Figure 40: PCM Audio Interface Slave Mode Timing Diagram ....................................................................................90
Figure 41: PCM Audio Interface Slave Mode (PCM Time Slot Mode )Timing Diagram ..............................................91
Figure 42: PCM Audio Interface Master Mode (PCM Time Slot Mode )Timing Diagram .............................................91
Figure 43: MCLK Timing Diagram ...............................................................................................................................92
Figure 44: DAC Filter Frequency Response................................................................................................................97
Figure 45: ADC Filter Frequency Response................................................................................................................97
Figure 46: DAC Filter Ripple .......................................................................................................................................97
Figure 47: ADC Filter Ripple .......................................................................................................................................97
Figure 48: Application Diagram For 20-Pin QFN .........................................................................................................98
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NAU8810
8.
List of Tables
Table 1: Pin Description ................................................................................................................................................4
Table 2: Register associated with Input PGA Control .................................................................................................18
Table 3: Microphone Non-Inverting Input Impedances .................................................................................................19
Table 4: Microphone Inverting Input Impedances .......................................................................................................19
Table 5: Registers associated with ALC and Input PGA Gain Control ........................................................................20
Table 6: Registers associated with PGA Boost Stage Control ....................................................................................20
Table 7: Register associated with Microphone Bias ....................................................................................................21
Table 8: Microphone Bias Voltage Control ..................................................................................................................22
Table 9: Register associated with ADC .......................................................................................................................23
Table 10: High Pass Filter Cut-off Frequencies (HPFAM=1) .......................................................................................23
Table 11: Registers associated with Notch Filter Function ..........................................................................................24
Table 12: Equations to Calculate Notch Filter Coefficients..........................................................................................24
Table 13: Register associated with ADC Gain ............................................................................................................24
Table 14: Registers associated with ALC Control .......................................................................................................27
Table 15: ALC Maximum and Minimum Gain Values ..................................................................................................27
Table 16: Registers associated with DAC Gain Control ..............................................................................................32
Table 17: Registers associated with Equalizer Control ...............................................................................................35
Table 18: Speaker Output Controls .............................................................................................................................37
Table 19: MONO Output Controls ...............................................................................................................................37
Table 20: General Purpose Control .............................................................................................................................41
Table 21: Registers associated with PLL ....................................................................................................................42
Table 22: Registers associated with PLL ....................................................................................................................43
Table 23: PLL Frequency Examples ...........................................................................................................................44
Table 24: Standard Interface modes ...........................................................................................................................48
Table 25: Audio Interface Control Registers................................................................................................................48
Table 26: Companding Control ...................................................................................................................................53
Table 27: Power up sequence.....................................................................................................................................56
Table 28: Power down Sequence ...............................................................................................................................57
Table 29: Registers associated with Power Saving .....................................................................................................57
Table 30: VDDA 3.3V Supply Current .........................................................................................................................58
Table 31: 2-WireTiming Parameters ...........................................................................................................................88
Table 32: Audio Interface Timing Parameters .............................................................................................................92
Table 33: MCLK Timing Parameter .............................................................................................................................92
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NAU8810
9.
ABSOLUTE MAXIMUM RATINGS
CONDITION
MIN
MAX
Units
VDDD, VDDA supply voltages
-0.3
+3.63
V
VDDSPK supply voltage (MOUTBST=0, SPKBST=0)
-0.3
+3.63
V
VDDSPK supply voltage (MOUTBST=1, SPKBST=1)
-0.3
+5.50
V
Core Digital Input Voltage range
VSSD – 0.3
VDDD + 0.30
V
Analog Input Voltage range
VSSA – 0.3
VDDA + 0.30
V
Industrial operating temperature
-40
+85
0
C
Storage temperature range
-65
+150
0
C
CAUTION: Do not operate at or near the maximum ratings listed for extended period. Exposure to such
conditions may adversely influence product reliability and result in failures not covered by warranty. These
devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
10. OPERATING CONDITIONS
Condition
Symbol
Min Value
Analogue supplies range
VDDA
Digital supply range
Speaker supply (MOUTBST=0,
SPKBST=0)
Speaker supply (MOUTBST=1,
SPKBST=1)
Ground
Typical
Value
Max Value
Units
2.501
3.60
V
VDDD
1.71
3.60
V
VDDSPK
2.50
3.60
V
VDDSPK
2.50
5.50
V
VSSD, VSSA,
VSSSPK
0
V
Note 1. VDDA must be ≥ VDDD.
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11. ELECTRICAL CHARACTERISTICS
VDDD = 1.8V, VDDA = VDDSPK = 3.3V (VDDSPK = 1.5*VDDA when Boost), TA = +25oC, 1kHz signal, fs =
48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Analogue to Digital Converter (ADC)
Full scale input signal 1
Signal to Noise Ratio 2
Total Harmonic Distortion
3
VINFS
PGABST = 0dB
PGAGAIN = 0dB
SNR
Gain = 0dB, A-weighted
THD
Input = -1dBFS, Gain = 0dB
87
1.0
0
VRMS
dBV
91
dB
-79
-65
dB
Digital to Analogue Converter (DAC) to MONO output (all data measured with 10kΩ / 50pF load)
Full Scale output signal
MOUTBST=0
1.0x
(VREF)
MOUTBST=1
1.5 x
VREF
1
Signal to Noise Ratio 2
SNR
A-weighted (ADC/DAC oversampling rate
of 128)
Total Harmonic Distortion 3
THD
RL = 10 KΩ; -1.0dBfs
90
Programmable input PGA gain
Guaranteed monotonic
PGABST = 0
Programmable Boost PGA
gain
Positive Microphone Input
resistance
RMIC+
Input Capacitance
CMIC
dB
VRMS
dBV
35.25
dB
dB
0
dB
20
Mute Attenuation
RAUX
-70
0.75
PGABST = 1
PGA equivalent output noise
dB
1
0
-12
Programmable Gain Step Size
Auxiliary Input resistance
93
-84
Microphone Inputs (MICN & MICP) and MIC Input Programmable Gain Amplifier (PGA)
PGABST = 0dB
Full-scale Input Signal Level 1
VINFS
PGAGAIN = 0dB
VRMS
100
dB
0 to 20kHz,
Gain set to 35.25dB
110
µV
PGA Gain = 35.25dB
1.6
kΩ
PGA Gain = 0dB
47
kΩ
PGA Gain = -12dB
75
kΩ
PMICPGA = 1
94
kΩ
10
pF
Speaker Output PGA
Programmable Gain
Programmable Gain Step Size
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Guaranteed monotonic
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1
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dB
dB
NAU8810
VDDD = 1.8V, VDDA = VDDSPK = 3.3V (VDDSPK = 1.5*VDDA when Boost), TA = +25oC, 1kHz signal, fs =
48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
BTL Speaker Output (SPKOUT+, SPKOUT- with 8Ω bridge tied load)
SPKBST = 0
VDDSPK = VDDA
7
Full scale output
SPKBST = 1
VDDSPK = 1.5 * VDDA
Output Power
PO
Signal to Noise Ratio
SNR
PSRR
UNIT
VDDA / 3.3
VRMS
(VDDA / 3.3) * 1.5
90
dB
VDDSPK = 1.5*VDDA
RL = 8Ω
90
dB
-63
dB
-56
dB
-60
dB
-61
dB
PO =1W
-34
dB
VDDSPK = 3V, SPKBST = 0
50
dB
VDDSPK = 1.5*VDDA, SPKBST = 1
50
dB
VDDA / 3.3
VRMS
90
dB
-84
dB
-85
dB
(MICBIASV = 0)
0.9*
VDD
A
V
(MICBIASV = 1)
0.65*
VDD
A
V
VDDSPK=3.3V
PO
=360mW
RL =
8Ω
VDDSPK =
1.5*VDDA
PO
=800mW
Power Supply Rejection Ratio
(50Hz - 22kHz)
MAX
VDDSPK = 3.3V
RL = 8Ω
PO
=400mW
THD
TYP
Output power is very closely correlated with THD;
see below
PO
=180mW
Total Harmonic Distortion
MIN
Headphone’ output (SPKOUTP, SPKOUTN with resistive load to ground)
Full scale output 7
Signal to Noise Ratio
SNR
A-weighted
Po = 20mW
Total Harmonic Distortion
THD
Po = 20mW
RL=16
Ω
RL=32
Ω
VDDSPK=3.3V
Microphone Bias
Bias Voltage
VMICBIAS
Bias Current Source
IMICBIAS
Output Noise Voltage
VN
3
mA
MICBIASM = 0
(1kHz to 20kHz)
14
nV/√Hz
MICBIASM = 1
(1kHz to 20kHz)
4
nV/√Hz
Automatic Level Control (ALC)/Limiter – ADC only
Target Record Level
-28.5
Programmable Gain
-6
dB
35.25
0.75
dB
dB
0 / 2.67 / …/ 43691
ms
-12
Programmable Gain Step Size
Gain Hold Time 4, 6
Guaranteed Monotonic
tHOLD
MCLK=12.288MHz
™
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(time doubles with
each step)
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NAU8810
VDDD = 1.8V, VDDA = VDDSPK = 3.3V (VDDSPK = 1.5*VDDA when Boost), TA = +25oC, 1kHz signal, fs =
48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Automatic Level Control (ALC)/Limiter – ADC only
Gain Ramp-Up (Decay) Time 5,
6
Gain Ramp-Down (Attack)
5, 6
Time
tDCY
tATK
ALC Mode
ALCM=0
MCLK=12.288MHz
3.3 / 6.6 / 13.1 / … /
3360 (time doubles every
step)
ms
Limiter Mode
ALCM=1
MCLK=12.288MHz
0.73 / 1.45 / 2.91 / … /
744 (time doubles every
step)
ms
ALC Mode
ALCM=0
MCLK=12.288MHz
0.83 / 1.66 / 3.33 / … /
852 (time doubles every
step)
ms
Limiter Mode
ALCM=1
MCLK=12.288MHz
0.18 / 0.36 / 0.73 / … /
186 (time doubles every
step)
ms
Digital Input / Output
0.7 ×
VDDD
Input HIGH Level
VIH
Input LOW Level
VIL
Output HIGH Level
VOH
IOL = 1mA
Output LOW Level
VOL
IOH = -1mA
V
0.3 ×
VDDD
0.9 ×
VDDD
V
0.1 x
VDDD
Notes
1. Full Scale is relative to VDDA (FS = VDDA/3.3.).
2. Signal-to-noise ratio (dB) - SNR is a measure of the difference in level between the full-scale output and the
output with no signal applied. (No Auto-zero or Automute function is employed in achieving these results).
3. THD+N (dB) - THD+N are a ratio, of the RMS values, of (Noise + Distortion)/Signal.
4. Hold Time is the length of time between a signal detected being too quiet and beginning to ramp up the gain.
It does not apply to ramping down the gain when the signal is too loud, which happens without a delay.
5. Ramp-up and Ramp-Down times are defined as the time to change the PGA gain by 6dB of its gain range.
6. All hold, ramp-up and ramp-down times scale proportionally with MCLK (specified for MCLK = 12.288MHz)
7. The maximum output voltage can be limited by the speaker power supply. If MOUTBST or SPKBST is, set
then VDDSPK should be 1.5xVDDA to prevent clipping taking place in the output stage (when PGA gains are set
to 0dB).
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NAU8810
12. FUNCTIONAL DESCRIPTION
The NAU8810 a Mono Audio CODEC with very robust ADC and DAC capabilities. The device provides one
differential microphone input pair (MIC- & MIC+ pins) supported by a two-stage amplification path for amplification
by as much as 55.25dB. Additionally, the MIC+ pin can be used independently from the MIC- pin enabling two
independent mixing inputs for some applications.
The device also has an internal configurable biasing circuit for biasing the microphone, which reduces external
components. The PGA output has programmable ADC gain. An advanced Sigma Delta ADC and DAC are used
along with digital decimation and interpolation filters to give high quality audio at sample rates from 8 KHz to 48
KHz. The Digital Filter blocks include ADC high pass filters, a Notch Filter, and a 5-band equalizer. The device
has two output mixers, one for the Mono output, and the other for the speaker output.
The NAU88U10 has a 2-Wire read/write serial control interface for device control. Audio data is supported in
many commonly used industry formats as either I2S or PCM formatted data.
Additionally, the PCM mode
supports time slotting for added design flexibility, such as in creation of multichannel systems using a shared
audio data bus.
The NAU88U10 can operate as a master or slave audio device. It can operate with sample rates ranging from 8
kHz to 48 kHz, depending on the values of MCLK and it is prescaler. The NAU88U10 includes a PLL block,
where it takes the external clock (MCLK pin) to generate other clocks for the audio data transfer such as Bit clock
(BCLK), Frame Sync (FS), and I2S clocks. The power control registers help save power by controlling the major
individual functional blocks of the NAU88U10.
12.1.
INPUT PATH
The NAU88U10 microphone inputs are maintained at a DC bias at approximately a half of the VDDA supply
voltage. Connections to these inputs should be AC-coupled by means of DC blocking capacitors suitable for the
device application.
12.1.1. The differential microphone input (MIC- & MIC+ pins)
The NAU88U10 features a low-noise, high common mode rejection ratio (CMRR), differential microphone inputs
(MIC- & MIC+ pins) 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 required in products such as
notebooks and PDAs. When properly employed, the differential input architecture offers an improved powersupply rejection ratio (PSRR) and higher ground noise immunity.
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NAU8810
PGAGAIN[5:0]
(0x2D)
NMICPGA[1]
(0x2C)
NMICPGA[1]
(0x2C)
R
MIC-
R
PGAGAIN[5:0]
(0x2D)
PMICPGA[0]
(0x2C)
MIC+
To PGA
Boost
R
-12 dB to +35.25 dB
VREF
PGAGAIN[5:0]
(0x2D)
Figure 3: Input PGA Circuit Block Diagram
Bit(s)
Addr
Parameter
Programmable Range
PMICPGA[0]
0x2C
Positive Microphone to PGA
0 = Input PGA Positive terminal to VREF
1 = Input PGA Positive terminal to MICP
NMICPGA[1]
0x2C
Negative Microphone to
PGA
0 = MICN not connected to input PGA
1 = MICN to input PGA Negative terminal.
Table 2: Register associated with Input PGA Control
12.1.1.1.
Positive Microphone Input (MIC+)
The positive microphone input (MIC+) can be used as part of the differential input. It connects to the positive
terminal of the PGA gain amplifier by setting PMICPGA[0] address (0x2C) to HIGH or can be connected to VREF
by setting PMICPGA[0] address (0x2C) to LOW.
In single ended applications where the MIC+ input is used without using MIC-, the PGA gain values will be valid
only if the MIC- pin is terminated to a low impedance signal point. This termination should normally be an AC
coupled path to signal ground. The non-inverting input impedance is constant regardless of the gain value. The
following table gives the nominal input impedance for both inputs. Impedance for specific gain values not listed in
this table can be estimated through interpolation between listed values.
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NAU8810
MIC+ to non-inverting PGA input
Nominal Input Impedance
MIC- to inverting PGA input
Nominal Input Impedance
Gain (dB)
Impedance (kΩ)
Gain (dB)
Impedance (kΩ)
-12
-9
-6
-3
0
3
6
9
12
18
30
35.25
94
94
94
94
94
94
94
94
94
94
94
94
-12
-9
-6
-3
0
3
6
9
12
18
30
35.25
75
69
63
55
47
39
31
25
19
11
2.9
1.6
Table 3: Microphone Non-Inverting
Input Impedances
12.1.1.2.
Table 4: Microphone Inverting Input
Impedances
Negative Microphone Input (MIC-)
The negative microphone input (MIC-) may be used as either a differential input in conjunction with MIC+, or as a
single ended input. This input connects to the negative terminal of the PGA gain amplifier by setting NMICPGA[1]
address (0x2C) to HIGH. When the MIC- is used as a single ended input, MIC+ should be connected to VREF by
setting PMICPGA[0] address (0x2C) bit to LOW, or MIC+ may be used as an independent input.
When the associated control bit is set logic = 1, the MIC- 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 MIC- pin close to VREF at all times. It is important for a system designer to know that the MIC-input
impedance varies as a function of the selected PGA gain. This is normal and expected for a difference amplifier
type topology. The above table gives the nominal resistive impedance values for this input over the possible gain
range. Impedance for specific gain values not listed in this table can be estimated through interpolation between
listed values.
12.1.1.3.
PGA Gain Control
The PGA amplification is common to both microphone input pins MIC-, MIC+, and enabled by PGAEN[2] address
(0x02). It has a range of -12dB to +35.25dB in 0.75dB steps, controlled by PGAGAIN[5:0] address (0x2D). Input
PGA gain will not be used when ALC is enabled using ALCEN[8] address (0x20).
Addr
Bit 8
Bit 7
Bit 6
0x2D
0
PGAZC
PGAMT
0x20
ALCEN
0
0
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Bit5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PGAGAIN[5:0]
ALCMXGAIN[2:0]
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Default
0x010
ALCMNGAIN[2:0]
0x038
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NAU8810
Table 5: Registers associated with ALC and Input PGA Gain Control
12.1.2.
PGA Boost / Mixer Stage
The boost stage has two inputs connected to the PGA Boost Mixer. Both inputs can be individually connected or
disconnected from the PGA Boost Mixer. The boost stage can be enabled by setting BSTEN[4] address (0x02) to
HIGH. The following figure shows the PGA Boost stage.
PGABST[8] PGAMT[6]
(0x2F)
(0x2D)
Output from
PGA Gain
To ADC
PMICBSTGAIN[6:4]
(0x2F)
MIC+
Pin
Figure 4: Boost Stage Block Diagram
The signal from the PGA stage to the PGA Boost Mixer is disconnected or muted by setting PGAMT[6] address
(0x2D) to HIGH. In this path, the PGA boost can be a fixed value of +20dB or 0dB, controlled by the PGABST[8]
address (0x2F) bit.
The signal from MIC+ pin to the PGA Boost Mixer is disconnected by setting ‘000’ binary value to
PMICBSTGAIN[6:4] address (0x2F) and any other combination connects the path.
Bit(s)
Addr
Parameter
Programmable Range
BSTEN[4]
0x02
Enable PGA Boost Block
0 = Boost stage OFF
1 = Boost stage ON
PGAMT[6]
0x2D
Mute control for input PGA
0=Input PGA not muted
1=Input PGA muted
PMICBSTGAIN[6:4]
0x2F
Boost MIC+ signal
Range: -12dB to +6dB @ 3dB increment
PGABST[8]
0x2F
Boost PGA stage
0 = PGA output has +0dB
1 = PGA output has +20dB
Table 6: Registers associated with PGA Boost Stage Control
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NAU8810
12.2.
MICROPHONE BIASING
MICBIASM[0]
(0x28)
VREF
MICBIAS
R
R
MICBIASV[1:0]
(0x2C)
Figure 5: Microphone Bias Schematic
The MICBIAS pin is a low-noise microphone bias source for an external microphone, and it can provide a
maximum of 3mA of bias current. This DC bias voltage either is suitable for powering 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 output bias can be enabled by setting MICBIASEN[4] address (0x01) to HIGH. It has various voltage values
selected by a combination of bits MICBIASM[4] address (0x3A) and MICBIASV[8:7] address (0x2C).
The low-noise feature results in greatly reduced noise in the external MICBIAS voltage by placing an internal
resistor of approximately 200-ohms in series with the output pin. This creates a low pass filter in conjunction with
the external microphone-bias filter capacitor, but without any other additional external components.
Bit(s)
Addr
Parameter
MICBIASEN[4]
0x01
MICBIASM[4]
(0x3A)
Microphone bias mode selection
MICBIASV[8:7]
(0x2C)
Microphone bias voltage selection
Microphone bias enable
Programmable Range
0 = Disable
1 = Enable
0 = Disable
1 = Enable
Table 7: Register associated with Microphone Bias
Below are the unloaded values when MICBIASM[4] is set to 1 and 0. When loaded, the series resistor will cause
the voltage to drop, depending on the load current.
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NAU8810
Microphone Bias Voltage Control
MICBIASV[8:7]
MICBIASM[4] = 0
MICBIASM[4]= 1
0
0
0.9* VDDA
0.85* VDDA
0
1
0.65* VDDA
0.60* VDDA
1
0
0.75* VDDA
0.70* VDDA
1
1
0.50* VDDA
0.50* VDDA
Table 8: Microphone Bias Voltage Control
12.3.
ADC DIGITAL FILTER BLOCK
ADC Digital Filters
ADC
Digital
Decimator
Digital
Filter
/
Gain
5-Band
Equalizer
High
Pass
Filter
Notch
Filter
Digital
Audio
Interface
Figure 6: ADC Digital Filter Path Block Diagram
The ADC digital filter block performs a 24-bit signal processing. The block consists of an oversampled analog
sigma-delta modulator, digital decimator, digital filter, 5-band graphic equalizer, high pass filter, and a notch filter.
For digital decimator and 5-band graphic equalizer details, refer to “Output Signal Path”. The oversampled analog
sigma-delta modulator provides a bit stream to the decimation stages and filter. 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 and any voltage greater than full scale may overload the ADC and cause distortion.
The ADC is enabled by setting ADCEN[0] address (0x02) bit. Polarity and oversampling rate of the ADC output
signal can be changed by ADCPL[0] address (0x0E) and ADCOS[3] address (0x0E) respectively.
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NAU8810
Bit(s)
Addr
Parameter
Programmable Range
ADCPL[0]
0x0E
ADCOS[3]
0x0E
HPFEN[8]
0x0E
HPFAM[7]
0x0E
Audio or Application Mode
0 = Audio (1st order, fc ~ 3.7 kHz)
1 = Application (2nd order, fc =HPF)
HPF[6:4]
0x0E
High Pass Filter frequencies
82 Hz to 612 Hz depending on the sample
rate
ADCEN[0]
0x02
Enable ADC
0 = Disable
1 = Enable
SMPLR[3:1]
0x07
Sample rate
8k Hz to 48 kHz
0 = Normal
1 = Inverted
ADC Polarity
0=64x (Lowest power)
1=128x (best SNR at typical condition)
ADC Over Sample
Rate
High Pass Filter
Enable
0 = Disable
1 = Enable
Table 9: Register associated with ADC
12.3.1. Programmable High Pass Filter (HPF)
The high pass filter (HPF) has two different operational modes set by bit HPFAM[7] at address (0x0E). In Audio
Mode (HPFAM=0), the filter is first order, with a cut-off frequency of 3.7Hz. In Application mode (HPFAM=1), the
filter is second order, with a cut-off frequency selectable via the HPF[2:0] register bits. Cut-off frequency of the
HPF depends on sample frequency selected by SMPLR[3:1] address (0x07). The HPF is enabled by setting
HPFEN[8] address (0x0E) to HIGH. Table below shows the cut-off frequencies with different sampling rates.
HPF[2:0]
8
SMPLR=101/100
11.025
12
fs (kHz)
SMPLR=011/010
16
22.05
24
SMPLR=001/000
32
44.1
48
000
82
113
122
82
113
122
82
113
122
001
102
141
153
102
141
153
102
141
153
010
131
180
156
131
180
156
131
180
156
011
163
225
245
163
225
245
163
225
245
100
204
281
306
204
281
306
204
281
306
101
261
360
392
261
360
392
261
360
392
110
327
450
490
327
450
490
327
450
490
111
408
563
612
408
563
612
408
563
612
Table 10: High Pass Filter Cut-off Frequencies (HPFAM=1)
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NAU8810
12.3.2. Programmable Notch Filter (NF)
The NAU88U10 has a programmable notch filter which passes all frequencies except those in a stop band
centered on a given center frequency. The filter gives lower distortion and flattens response. The notch filter is
enabled by setting NFCEN[7] address (0x1B) to HIGH. The variable center frequency is programmed by setting
two’s complement values to NFCA0[6:0] address (0x1C), NFCA0[13:7] address (0x1B) and NFCA1[6:0] address
(0x1E), NFCA1[13:7] address (0x1D) registers. The coefficients are updated in the circuit when the NFCU[8] bit
is set HIGH in a write to any of the registers NF1-NF4 address (0x1B, 0x1C, 0x1D, 0x1E).
Addr
Bit 8
Bit 7
Bit 6
Bit5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Default
0x1B
NFCU
NFCEN
NFCA0[13:7]
0x000
0x1C
NFCU
0
NFCA0[6:0]
0x000
0x1D
NFCU
0
NFCA1[13:7]
0x000
0x1E
NFCU
0
NFCA1[6:0]
0x000
Table 11: Registers associated with Notch Filter Function
A0
Coefficient
A1
2 fb
1 tan
2 fs
2 fb
1 tan
2 fs
1 A0
2 fc
x cos
fs
Notation
Register Value (DEC)
fc = center frequency (Hz)
fb = -3dB bandwidth (Hz)
fs = sample frequency
(Hz)
NFCA0 = -A0 x 213
NFCA1 = -A1 x 212
(then convert to 2’s
complement)
Table 12: Equations to Calculate Notch Filter Coefficients
12.3.3. Digital ADC Gain Control
The digital ADC can be muted by setting “0000 0000” to ADCGAIN[7:0] address (0x0F). Any other combination
digitally attenuates the ADC output signal in the range -127dB to 0dB in 0.5dB increments].
Addr
Name
Bit 8
0x0F
ADCG
0
Bit 7
Bit 6
Bit5
Bit 4
Bit 3
Bit 2
ADCGAIN
Bit 1
Bit 0
Default
0x0FF
Table 13: Register associated with ADC Gain
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12.4. PROGRAMMABLE GAIN AMPLIFIER (PGA)
NAU88U10 has a programmable gain amplifier (PGA) which controls the gain under program control, or
automatically supporting either of these two features:
Automatic level control (ALC) or
Input peak limiter
The Automatic Level Control (ALC) seeks to control the PGA gain in response to the amplitude of the input signal
such that the PGA output maintains a relatively constant level. The peak limiter simply prevents the output signal
from exceeding a specified level.
12.4.1.
Automatic level control (ALC)
The ALC seeks to control the PGA gain such that the PGA output maintains a constant envelope. This helps to
prevent clipping at the input of the sigma delta ADC while maximizing the full dynamic range of the ADC. The
ALC monitors the output of the ADC, and adjusts the PGA gain as required. 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. Based on a comparison between the measured
peak value and the target value, the ALC block adjusts the gain control, which is fed back to the PGA.
Rate Convert/ Decimator
Input
Pin
PGA
ADC
Sinc
Filter
Digital
Decimator
Digital
Filter
ALC
Figure 7: ALC Block Diagram
The ALC is enabled by setting ALCEN[8] address (0x20) bit to HIGH. The ALC has two functional modes, which
is set by ALCM[8] address (0x22).
Normal mode (ALCM = LOW)
Peak Limiter mode (ALCM = HIGH)
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When the ALC is disabled, the input PGA remains at the last controlled value of the ALC. An input gain update
must be made by writing to the PGAGAIN[5:0] address (0x2D). A digital peak detector monitors the input signal
amplitude and compares it to a register defined threshold level ALCSL[3:0] address (0x21).
Output Level
Blue
Green
Red
Input < noise
gate threshold
Original Input signal (linear line from zero to maximum)
PGA gain value over time (inverse to signal in target range)
Output signal (held to a constant value in target range)
ALC operation range
Target ALCSL -6dB
Gain (Attenuation) Clipped
at ALCMNGAIN -12dB
+33 dB
PGA Gain
0 dB
-12 dB
ALCNEN = 1
ALCNTH = -39dB
MIC Boost Gain = 0dB
ALCSL = -6dB
ALCMNGAIN = -12dB
ALCMXGAIN = +35.25dB
-39dB
-39dB
-6dB +6dB
Input Level
Figure 8: ALC Response Graph
The registers listed in the following section allow configuration of ALC operation with respect to:
ALC target level
Gain increment and decrement rates
Minimum and maximum PGA gain values for ALC operating range
Hold time before gain increments in response to input signal
Inhibition of gain increment during noise inputs
Limiter mode operation
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NAU8810
Bit(s)
Addr
ALCMNGAIN[2:0]
Parameter
Programmable Range
Minimum Gain of PGA
Range: -12dB to +30dB @ 6dB increment
Maximum Gain of PGA
Range: -6.75dB to +35.25dB @ 6dB increment
ALCEN[8]
Enable ALC function
0 = Disable
1 = Enable
ALCSL[3:0]
ALC Target
Range: -28.5dB to -6dB @ 1.5dB increment
ALC Hold Time
Range: 0ms to 1s, time doubles with every step)
ALCZC[8]
ALC Zero Crossing
0 = Disable
1 = Enable
ALCATK[3:0]
ALC Attack time
ALCM=0 - Range: 125us to 128ms
ALCM=1 - Range: 31us to 32ms (time doubles with
every step)
ALC Decay time
ALCM=0 - Range: 500us to 512ms
ALCM=1 - Range: 125us to 128ms
(Both ALC time doubles with every step)
ALC Select
0 = ALC mode
1 = Limiter mode
ALCMXGAIN[2:0]
ALCHT[3:0]
0x20
0x21
0x22
ALCDCY[3:0]
ALCM[8]
Table 14: Registers associated with ALC Control
The operating range of the ALC is set by ALCMXGAIN[5:3] address (0x20) and ALCMNGAIN[2:0] address (0x20)
bits such that the PGA gain generated by the ALC is between the programmed minimum and maximum levels.
When the ALC is enabled, the PGA gain is disabled.
In Normal mode, the ALCMXGAIN bits set the maximum level for the PGA in the ALC mode but in the Limiter
mode ALCMXGAIN has no effect because the maximum level is set by the initial PGA gain setting upon enabling
of the ALC.
ALCMAXGAIN
Maximum Gain (dB)
ALCMINGAIN
Minimum Gain (dB)
111
110
35.25
29.25
000
001
-12
-6
ALC Max Gain Range 35.25dB to -6dB @
6dB increments
001
000
-0.75
-6.75
ALC Min Gain Range -12dB to 30dB @
6dB increments
110
111
24
30
Table 15: ALC Maximum and Minimum Gain Values
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12.4.1.1.
Normal Mode
Normal mode is selected when ALCM[8] address (0x22) is set LOW and the ALC is enabled by setting ALCEN[8]
address (0x20) HIGH. This block adjusts the PGA gain setting up and down in response to the input level. A
peak detector circuit measures the envelope of the input signal and compares it to the target level set by
ALCSL[3:0] address (0x21). The ALC increases the gain when the measured envelope is greater than the target
and decreases the gain when the measured envelope is less than - 1.5dB. The following waveform illustrates the
behavior of the ALC.
PGA Input
PGA Output
PGA Gain
Figure 9: ALC Normal Mode Operation
12.4.1.2.
ALC Hold Time (Normal mode Only)
The hold parameter ALCHT[3:0] configures the time between detection of the input signal envelope being outside
of the target range and the actual gain increase.
Input signals with different characteristics (e.g., voice vs. music) may require different settings for this parameter
for optimal 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, on the other hand, 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 ALCHT parameter.
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PGA Input
PGA Output
PGA Gain
Hold Delay
Change
Figure 10: ALC Hold Time
12.4.2. Peak Limiter Mode
Peak Limiter mode is selected when ALCM[8] address (0x22) is set to HIGH and the ALC is enabled by setting
ALCEN[8] address (0x20). In limiter mode, the PGA gain is constrained to be less than or equal to the gain
setting at the time 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 11: ALC Limiter Mode Operations
When the input signal exceeds 87.5% of full scale, the ALC block ramps down the PGA gain at the maximum
attack rate (ALCATK=0000), regardless of the mode and attack rate settings until the ADC output level has been
reduced below this threshold. This minimizes ADC clipping, if there is a sudden increase in the input signal level.
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12.4.3. Attack Time
When the absolute value of the ADC output exceeds the level set by the ALC threshold, ALCSL[3:0] address
(0x21), attack mode is initiated at a rate controlled by the attack rate register ALCATK[3:0] address (0x22). The
peak detector in the ALC block loads the ADC output value when the absolute value of the ADC output exceeds
the current measured peak; otherwise, the peak decays towards zero, until a new peak has been identified. This
sequence is continuously running. If the peak is ever below the target threshold, then there is no gain decrease
at the next attack timer time; if it is ever above the target-1.5dB, then there is no gain increase at the next decay
timer time.
12.4.4. Decay Times
The decay time ALCDCY[6:4] address (0x22) is the time constant used when the gain is increasing. In limiter
mode, the time constants are faster than in ALC mode.
12.4.5. Noise gate (normal mode only)
A noise gate may be used to limit the ALC gain when there is no input signal, or a signal less than the noise gate
threshold. This noise from excess input gain, when there is no useful signal to amplify. The noise gate is enabled
by setting ALCNEN[3] address (0x23) to HIGH. It does not remove noise from the signal. The noise gate
threshold ALCNTH[2:0] address (0x23) is set to a desired level so when there is no signal or a very quiet signal
(pause), which is composed mostly of noise, the ALC holds the gain constant instead of amplifying the signal
towards the target threshold. The noise gate only operates in conjunction with the ALC and ONLY in Normal
mode. The noise gate flag is asserted when
(Signal at ADC – PGA gain – MIC Boost gain) < ALCNTH (ALC Noise Gate Threshold) (dB)
Levels at the extremes of the range may cause inappropriate operation, so care should be taken when setting up
the function.
PGA Input
PGA Output
PGA Gain
Figure 12: ALC Operation with Noise Gate disabled
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PGA Input
Noise Gate Threshold
PGA Output
PGA Gain
Figure 13: ALC Operation with Noise Gate Enabled
12.4.6. Zero Crossing
The PGA gain comes from either the ALC block when the ALC is enabled, or directly from the PGA gain register
setting when the ALC is disabled. Zero crossing detection may be enabled to force PGA gain changes to occur
only at an input zero crossing events. Enabling zero crossing detection limits clicks and pops that will occur if the
gain changes while the input signal is at a voltage that is significantly higher or lower than zero.
There are two zero crossing detection enables:
Register ALCZC[8] address (0x21) – is only relevant when the ALC is enabled.
Register PGAZC[7] address (0x2D) – is only relevant when the ALC is disabled.
If the zero crossing function is enabled (using either register) and SCLKEN[0] address (0x07) is asserted, the zero
cross timeout function may take effect. If the zero crossing flag does not change polarity within 0.25 seconds of a
PGA gain update (either via ALC update or PGA gain register update), then the gain will update automatically.
This backup system prevents the gain from locking up if the input signal has a small swing and/or a DC offset that
prevents the zero crossing flag from triggering.
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12.5.
DAC DIGITAL FILTER BLOCK
DAC Digital Filters
Digital
Audio
Interface
Digital
Gain
Digital
Peak
Limiter
5-Band
Equalizer
Digital
Filters
Interpolation
Sigma
Delta
Modulator
DAC
Figure 14: DAC Digital Filter Path
The DAC digital block uses 24-bit signal processing to generate analog audio using data from the audio data bus
or from the ADC output. This block consists of a sigma-delta modulator, 5-band graphic equalizer, high pass filter,
digital gain/filters, de-emphasis, and analog mixers. 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. The DAC is enabled by setting DACEN[0] address (0x03) bit HIGH.
Bit(s)
Addr
Parameter
Programmable Range
DACEN[0]
0x03
DAC enable
0 = Disable
1 = Enable
ADDAP[0]
0x05
Pass-through of ADC output data
into DAC input
0 = Disable
1 = Enable
DACPL[0]
DAC Polarity
0 = No Inversion
1 = DAC Output Inverted
AUTOMT[2]
Auto Mute
0 = Disable
1 = Enable
DEEMP[5:4]
Sample Rate
32 kHz, 44.1 kHz, and 48 kHz
DACMT[6]
Soft Mute
0 = Disable
1 = Enable
DAC Volume Control
Range: -127dB to 0dB @ 0.5dB
increment, 00 hex is Muted
DAC Limiter Attack
Range: 68us to 139ms
DAC Limiter Decay
Range: 544us to 1.1s
DAC Limiter Enable
0 = Disable
1 = Enable
DAC Limiter Volume Boost
Range: 0dB to +12dB @ 1dB
increment
DAC Limiter Threshold
Range: -6dB to -1bB @ 1dB increment
0x0A
DACGAIN[7:0]
0x0B
DACLIMATK[3:0]
DACLIMDCY[7:4]
0x18
DACLIMEN[8]
DACLIMBST[3:0]
0x19
DACLIMTHL[6:4]
Table 16: Registers associated with DAC Gain Control
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12.5.1.
DAC Soft Mute
The NAU88U10 also has a Soft Mute function, which smoothly attenuates the volume of the digital signal to zero.
When un-muted, the gain will ramp back up to the register determined digital gain setting. This feature provides a
tool that is useful to enable/disable DAC output without introducing pop and click sounds. To output any DAC
signal, Soft Mute must be disabled by setting the DACMT[6] address (0x0A) bit to LOW.
12.5.2.
DAC Auto Mute
The output of the DAC can also be muted by the analog Auto Mute function. The Auto Mute function is enabled
by setting AUTOMT[2] address (0x0A) to HIGH and applied to the DAC output when there are 1024 or more
consecutive zeros at its input. If at any time there is a non-zero DAC input sample value, the DAC will be unmuted, and the 1024 count will be reinitialized to zero.
12.5.3.
DAC Sampling / Oversampling rate, Polarity, DAC Volume control and 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 64x or 128x. In the 128x oversampling mode,
audio performance is improved 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 the DAC output signal can be changed as a feature, and this can useful in management of the
audio phase. This feature can help minimize audio processing that may be otherwise required as the data are
passed to other stages in the system.
The effective output audio volume of the 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.
Digital audio pass-through allows the output of the ADC to be directly sent to the DAC 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
pass-through 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.
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12.5.4.
Hi-Fi DAC De-Emphasis and Gain Control
The NAU88U10 has Hi-Fi DAC gain control for signal conditioning. The level of attenuation for an eight-bit code
X is given by:
for 1 ≤ X ≤ 255;
0.5 × (X-255) dB
MUTE for X = 0
It includes on-chip digital de-emphasis and is available for sample rates of 32 kHz, 44.1 kHz, and 48 kHz. The
digital de-emphasis can be enabled by setting DEEMP[5:4] address (0x0A) bits depending on the input sample
rate. The de-emphasis feature is included to accommodate audio recordings that utilize 50/15 s pre-emphasis
equalization as a means of noise reduction.
12.5.5.
Digital DAC Output Peak Limiter
Output Peak-Limiters optimize the dynamic range by ensuring the signal will not exceed a certain threshold, while
maximizing the RMS of the resulted audio signal, and minimizing audible distortions. NAU88U10 has a digital
output limiter function. The operation of this is shown in figure below. In this diagram, the upper graph shows the
envelope of the input/output signals and the lower graph shows the gain characteristic.
The limiter has a
programmable threshold, DACLIMTHL[6:4] address (0x19), which ranges from -1dB to -6dB in 1dB increments.
The digital peak limiter seeks to keep the envelope of the output signal within the target threshold +/- 0.5dB. The
attack and decay rates programmed in registers DACLIMATK[3:0] address (0x18) and DACLIMDCY[7:4] address
(0x18) specify how fast the digital peak limiter decrease and increase the gain, respectively, in response to the
envelope of the output signal falling outside of this range. In normal operation LIMBST=000 signals below this
threshold are unaffected by the limiter.
DAC Input
Data
Threshold
-1dB
DAC Output
Signal
0dB
Digital Gain
-0.5dB
-1dB
Figure 15: DAC Digital Limiter Control
12.5.6.
Volume Boost
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The limiter has programmable upper gain, which boosts signals below the threshold to compress the dynamic
range of the signal and increase its perceived loudness. This operates as an ALC function with limited boost
capability. The volume boost is from 0dB to +12dB in 1dB steps, controlled by the DACLIMBST[3:0] register bits.
The output limiter volume boost can also be used as a stand-alone digital gain boost when the limiter is disabled.
12.5.7.
5-Band Equalizer
NAU88U10 features 5-band graphic equalizer with low distortion, low noise, and wide dynamic range, and is an
ideal choice for Hi-Fi applications. All five bands are fully parametric with independently adjustable bandwidth
that displays exceptional tonal qualities. Each of the five bands offers +/- 12dB of boost and cut with 1dB
resolution. The five bands are divided in to three sections Low, Mid and High bands. The High and the Low
bands are shelving filters and the mid three are peak filters. The equalizer can be applied to the ADC or DAC
path under control of the EQM[8] address (0x12) register bit.
Bit(s)
Address
EQM[8]
EQ1CF[6:5]
Parameter
Programmable Range
Equalizer Enable
Band 1 Cut-off Frequency
Range: 80 Hz to 175 Hz
EQ1GC[4:0]
Band 1 Gain Control
Range: -12 dB to +12 dB
@ 1.0dB increment
EQ2BW[8]
Band 2 Equalizer Bandwidth
Narrow or Wide
Band 2 Centre Frequency
Range: 230 Hz to 500 Hz
EQ2GC[4:0]
Band 2 Gain Control
Range: -12 dB to +12 dB
@ 1.0dB increment
EQ2BW[8]
Band 3 Equalizer Bandwidth
Narrow or Wide
Band 3 Centre Frequency
Range: 650 Hz to 1.4 kHz
EQ3GC[4:0]
Band 3 Gain Control
Range: -12 dB to +12 dB
@ 1.0dB increment
EQ4BW[8]
Band 4 Equalizer Bandwidth
Narrow or Wide
Band 4 Centre Frequency
Range: 1.8 kHz to 4.1 kHz
Band 4 Gain Control
Range: -12 dB to +12 dB
@ 1.0dB increment
Band 5 Cut-off Frequency
Range: 5.3 kHz to 11.7 kHz
Band 5 Gain Control
Range: -12 dB to +12 dB
@ 1.0dB increment
EQ2CF[6:5]
EQ3CF[6:5]
EQ4CF[6:5]
0x12
0x13
0x14
0x15
EQ4GC[4:0]
EQ5CF[6:5]
0x16
EQ5GC[4:0]
Table 17: Registers associated with Equalizer Control
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12.6. ANALOG OUTPUTS
The NAU88U10 features two different types of outputs, a single-ended or differential Mono output (MOUT) and a
differential speaker outputs (SPKOUT+ and SPKOUT-).
The speaker amplifiers designed to drive a load
differentially; a configuration referred to as Bridge-Tied Load (BTL).
MOUTBST[3]
(0x31)
Output from
Auxiliary Amplifier
VDDSPK
MOUTMXEN[3]
(0x03)
DACOUT[0]
(0x38)
DAC Output
MOUT
MONO
MIXER
MOUTBST GAIN
0
1.0x
1
1.5x
DC output
1.0 x VREF
1.5 x VREF
-10dB or +0dB
SIDETONE
Output from PGA Boost
VSSSPK
VDDSPK
Zero Cross
Detection
SPEAKER
MIXER
-1
SPKOUTSPKBST GAIN
0
1.0x
1
1.5x
DC output
1.0 x VREF
1.5 x VREF
SPKOUT+
-10dB or 0dB
SPKMXEN[2]
(0x03)
SPKVOL[5:0]
(0x36)
Zero Cross
Detection
Buffer
SPKBST[2]
(0x31)
VSSSPK
Figure 16: Speaker and MONO Analogue Outputs [To Update ? output from Auxiliary Amplifier]
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
12.6.1.
Speaker Mixer Outputs
The speaker amplifiers are designed to drive a load differentially; a configuration referred to as Bridge-Tied Load
(BTL). The differential speaker outputs can drive a single 8Ω speaker or two headphone loads of 16Ω or higher,
including differential line output applications. Driving the load differentially doubles the output voltage. The output
of the speaker can be manipulated by changing attenuation and the volume (loudness of the output signal).
The output stage is powered by the speaker supply, VDDSPK, which are capable of driving up to 1.5VRMS signals
(equivalent to 3VRMS into a BTL speaker). The speaker outputs can be controlled and can be muted individually.
The output pins are at reference DC level when the output is muted.
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Bit(s)
Addr
Parameter
Programmable Range
SPKMXEN[2]
0x03
Speaker Mixer enable
0 – Disabled
1 – Enabled
PSPKEN[5]
0x03
Speaker positive terminal
enable
0 – Disabled
1 – Enabled
NSPKEN[6]
0x03
Speaker negative terminal
enable
0 – Disabled
1 – Enabled
SPKATT[1]
0x28
Speaker output attenuation
0 - 0dB
1 - -10dB
SPKBST[2]
0x31
Speaker output Boost
0 – (1.0x VREF) Boost
1- (1.5 x VREF) Boost
SPKGAIN[5:0]
0x36
Speaker output Volume
Range: -57dB to +6dB @ 6dB increment
SPKMT[6]
0x36
Speaker output Mute
0 – Speaker Enabled
1 – Speaker Muted
Table 18: Speaker Output Controls
12.6.2. Mono Mixer Output
The single ended output can drive headphone loads of 16Ω or 32Ω or a line output.
The MOUT can be
manipulated by changing attenuation and the volume (loudness of the output signal).
The output stage is powered by the speaker supply, VDDSPK, which are capable of driving up to 1.5VRMS signals.
The Mono output can be enabled for signal output or muted. The output pins are at reference DC level when the
output is muted.
Bit(s)
Addr
Parameter
Programmable Range
MOUTMXEN[3]
0x03
MONO mixer enable
0 – Disabled
1 – Enabled
MOUTEN[7]
0x03
MONO output enable
0 – Disabled
1 – Enabled
MOUTATT[2]
0x28
MONO output attenuation
0 - 0dB
1 - -10dB
MOUTBST[3]
0x31
MONO output boost
0 – (1.0x VREF) Boost
1 - (1.5 x VREF) Boost
MOUTMXMT[6]
0x38
MONO Output Mixer Mute
0 – MONO Mixer Normal Mode
1 – MONO Mixer Muted
MOUTMT[4]
0x45
MONO Output Mute
0 – MONO Output Normal Mode
1 – MONO Output Muted
Table 19: MONO Output Controls
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12.6.3. Differential Output Configuration
The NAU88U10 features two different types of outputs, a single-ended or differential Mono output (MOUT) and a
differential speaker output (SPKOUT+ and SPKOUT-). The speaker amplifiers are designed to drive a load
differentially as Bridge-Tied Load (BTL).
Three differential output options can be configured from the three output pins: MOUT, SPKOUT+ and SPKOUT. To enable differential outputs, three registers need to be configured accordingly: SPK2MOUT=1 (0x45[5]),
AOUTMP=1 (0x31[0]) and 0x4F=0x100.
-
Option 1: Two differential outputs by using pair of MOUT and SPKOUT-, SPKOUT+ and SPKOUT- for driving
both headphone/earpiece and Speaker. Register setting: MOUTEN=1, NSPKEN=1, and PSPKEN =1
-
Option 2: One differential output by using MOUT and SPKOUT- for driving headphone/earpiece. Register
setting: MOUTEN=1, NSPKEN=1, and PSPKEN =0
-
Option 3: One differential output by using SPKOUT+ and SPKOUT- for driving speaker. Register setting:
MOUTEN=0, NSPKEN=1 and PSPKEN =1
12.6.4. Unused Analog I/O
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SMOUT[3]
(0x4F)
MIC-
MOUTBST[3] = 1
(0x31)
30k
1K
NMICPGA[1]
(0x2C)
MIC+
MOUT
30K
40k
PMICPGA[0]
(0x2C)
MOUTBST[3] = 0
(0x31)
SPSPK[4]
(0x4F)
1.0 x VREF
1K
VREF
SPKOUT+
SNSPK[5]
(0x4F)
SBUFH[7]
(0x4F)
DCBUFEN[8]
(0x01)
SPKBST[2] = 0
(0x31)
SBUFL[6]
(0x4F)
IOBUFEN[2]
(0x01)
SPKBST[2] = 1
(0x31)
30K
1K
SPKOUT-
1.5 x VREF
30K
AOUTIMP[0]
(0x31)
R
R
Figure 17: Tie-off Options for the Speaker and MONO output Pins
In audio and voice systems, any time there is a sudden change in voltage to an audio signal, an audible pop or
click
sound may be the result.
Systems that change inputs and output configurations dynamically, or which are
required to manage low power operation, need special attention to possible pop and click situations.
The
NAU88U10 includes many features, which may be used to greatly reduce or eliminate pop and click sounds. The
most common cause of a pop or click signal is a sudden change to an input or output voltage. This may happen
either in a DC coupled system, or in an AC coupled system.
The strategy to control pops and clicks is similar for both a DC coupled system and an AC coupled system. The
case of the AC coupled system is the most common and the more difficult situation, and therefore, the AC
coupled case will be the focus for this information section. When an input or output pin is being used, the DC
level of that pin will be very close to half of the VDDA voltage that is present on the VREF pin. The only exception
is that when outputs are operated in the 5-Volt mode known as the 1.5x boost condition, then the DC level for
those outputs will be equal to 1.5xVREF. In all cases, any input or output capacitors will become charged to the
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operating voltage of the used input or output pin. The goal to reduce pops and clicks is to insure that the charge
voltage on these capacitors does not change suddenly at any time.
When an input or output is in a not-used operating condition, it is desirable to keep the DC voltage on that pin at
the same voltage level as the DC level of the used operating condition. This is accomplished using special
internal DC voltage sources that are at the required DC values. When an input or output is in the not-used
condition, it is connected to the correct internal DC voltage as not to have a pop or click. This type of connection
is known as a “tie-off” condition.
Two internal DC voltage sources are provided for making tie-off connections. One DC level is equal to the VREF
voltage value, and the other DC level is equal to 1.5x the VREF value. All inputs are always tied off to the VREF
voltage value. Outputs will automatically be tied to either the VREF voltage value or to the 1.5xVREF value,
depending on the value of the “boost” control bit for that output. That is to say, when an output is set to the 1.5x
gain condition, then that same output will automatically use the 1.5xVREF value for tie-off in the not-used
condition. The input pull-ups are connected to IOBUFEN[2] address (0x01) buffer with a voltage source (VREF).
The output pull-ups can be connected two different buffers depending on the voltage source.
IOBUFEN[2]
address (0x01) buffer is enabled if the voltage source is (VREF) and DCBUFEN[8] address (0x01) buffer is
enabled if the voltage source is (1.5 x VREF). IOBUFEN[2] address (0x01) buffer is shared between input and
output pins.
To conserve power, these internal voltage buffers may be enabled/disabled using control register settings. To
better manage pops and clicks, there is a choice of impedance of the tie-off connection for unused outputs. The
nominal values for this choice are 1kΩ and 30kΩ. The low impedance value will better maintain the desired DC
level in the case when there is some leakage on the output capacitor or some DC resistance to ground at the
NAU88U10 output pin. A tradeoff in using the low-impedance value is primarily that output capacitors could
change more suddenly during power-on and power-off changes.
Automatic internal logic determines whether an input or output pin is in the used or un-used condition. This logic
function is always active. An output is determined to be in the un-used condition when it is in the disabled
unpowered condition, as determined by the power management registers. An input is determined to be in the unused condition when all internal switches connected to that input are in the “open” condition.
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12.7. GENERAL PURPOSE CONTROL
12.7.1. Slow Timer Clock
Addr
D8
D7
D6
D5
D4
0x07
0
0
0
0
0
D3
D2
D1
D0
Default
SCLKEN 0x000
SMPLR[2:0]
Table 20: General Purpose Control
An internal Slow Timer Clock is supplied to automatically control features that happen over a relatively long period
of time, or time-spans.
This enables the NAU88U10 to implement long time-span features without any
host/processor management or intervention.
The Slow Timer Clock supports automatic time out for the zero-crossing hold off PGA volume changes. If this
feature is required, the Slow Timer Clock must be enabled. The Slow Timer Clock is initialized in the disabled
state.
The Slow Timer Clock rate is derived from MCLK using an integer divider that is compensated for the sample rate
as indicated by the register address (0x07).
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 register 0x07 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.
12.8.
CLOCK GENERATION BLOCK
ADCOS[3]
(0x0E)
f1
MCLK
MCLKSEL[7:5]
(0x06)
fPLL
PLLMCLK[4]
(0x24)
PLL1
R=f2/f1
f2
IMCLK
f/N
f/4
ADC
f/N
f/N
DAC
f/2
DACOS[3]
(0x0A)
CLKM[8]
(0x06)
PLL BLOCK
BCLKSEL[4:2]
(0x06)
…
GPIO1
/CSb
IMCLK/
N
IMCLK/
256
CLKIOEN[0]
(0x06)
f/N
Digital Audio
Interface
FS
BCLK
GPIO1PLL[5:4]
(0x08)
GPIO1SEL[2:0]
(0x08)
Figure 18: PLL and Clock Select Circuit
emPowerAudio™
Datasheet Revision 2.8
Page 41 of 102
March 1, 2017
NAU8810
The NAU88U10 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 NAU88U10 by means
of the control logic described in the Digital Audio Interfaces section. The Frame Sync (FS) and Bit Clock (BCLK)
pins in the Digital Audio Interface manage the audio bit rate and audio sample rate for this data flow.
It is important to understand that the Digital Audio Interface does not determine the sampling rate for the ADC and
DAC data converters, and instead, this rate is derived exclusively from the Internal Master Clock (IMCLK). It is
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. 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.
Addr
D8
D7
D6
D5
D4
0x01
DCBUFEN
0
PLLEN
MICBIASEN
0x06
CLKM
0x07
0
0
0
0
0
0x24
0
0
0
0
PLLMCLK
0x25
0
0
0
MCLKSEL[2:0]
D3
D2
D1
ABIASEN IOBUFEN
BCLKSEL[2:0]
PLLN[3:0]
PLLK[23:18]
Default
REFIMP
0
SMPLR[2:0]
D0
CLKIOEN
0x140
SCLKEN
0x000
0x008
0x00C
0x26
PLLK[17:9]
0x093
0x27
PLLK[8:0]
0x0E9
Table 21: Registers associated with PLL
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.
emPowerAudio™
Datasheet Revision 2.8
Page 42 of 102
March 1, 2017
NAU8810
12.8.1.
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 NAU88U10, 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 NAU88U10), 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. In addition, 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:
Equations
Description
IMCLK = (256) * (desired codec
sample rate)
IMCLK = desired Master Clock
f2 = (4 * P * IMCLK)
where P is the Master Clock divider
integer value;
optimal f2: 90MHz< f2 300 uA
161k/595k < 100 uA
40uA
600uA
MICBIASEN[4]
500 uA
PLLEN[5]
2.5mA Clocks Applied
DCBUFEN[8]
80uA
x64 - ADCOS= 0 => 2.0mA
x128 – ADCOS= 1 => 3.0mA
400uA
ADCEN[0]
PGAEN[2]
0x02
BSTEN[4]
200 uA
X64 (DACOS=0)=>1.6mA
x128(DACOS=1)=>1.7mA
400uA
DACEN[0]
SPKMXEN[2]
MOUTMXEN[3]
0x03
200uA
NSPKEN[6]
1mA from VDDSPK + 100uA (VDDA = 5V mode)
PSPKEN[5]
1mA from VDDSPK + 100uA (VDDA = 5V mode)
MOUTEN[7]
100uA
Table 30: VDDA 3.3V Supply Current
emPowerAudio™
Datasheet Revision 2.8
Page 58 of 102
March 1, 2017
NAU8810
13. REGISTER DESCRIPTION
Register
Address
Register Bits
Register Names
DEC HEX
0
0
Default
D8
D7
D6
D5
Software Reset
D4
D3
D2
D1
D0
RESET (SOFTWARE)
000
POWER MANAGEMENT
1
01
Power Management 1 DCBUFEN
0
0
PLLEN
MICBIASEN
ABIASEN
IOBUFEN
2
02
Power Management 2
0
0
0
0
BSTEN
0
PGAEN
3
03
Power Management 3
0
MOUTEN
NSPKEN
PSPKEN
0
REFIMP
000
0
ADCEN
000
0
DACEN
000
ADCPHS
0
050
ADDAP
000
CLKIOEN
140
SCLKEN
000
DACPL
000
MOUTMXEN SPKMXEN
AUDIO CONTROL
4
04
Audio Interface
BCLKP
FSP
0
0
5
05
Companding
6
06
Clock Control 1
CLKM
7
07
Clock Control 2
0
0
0
10
0A
DAC CTRL
0
0
DACMT
11
0B
DAC Volume
0
14
0E
ADC CTRL
15
0F
ADC Volume
HPFEN
WLEN[1:0]
0
AIFMT[1:0]
0
DACPHS
DACCM[1:0]
MCLKSEL[2:0]
ADCCM[1:0]
BCLKSEL[2:0]
0
0
0
SMPLR[2:0]
DEEMP[1:0]
DACOS
AUTOMT
0
DACGAIN
HPFAM
HPF[2:0]
0FF
ADCOS
0
0
0
ADCPL
ADCGAIN
100
0FF
EQUALISER
18
0x12 EQ1-Low Cutoff
EQM
0
EQ1CF[1:0]
EQ1GC[4:0]
12C
19
0x13 EQ2-Peak 1
EQ2BW
0
EQ2CF[1:0]
EQ2GC[4:0]
02C
20
0x14 EQ3-Peak 2
EQ3BW
0
EQ3CF[1:0]
EQ3GC[4:0]
02C
21
0x15 EQ4-Peak3
EQ4BW
0
EQ4CF[1:0]
EQ4GC[4:0]
02C
22
0x16 EQ5-High Cutoff
0
0
EQ5CF[1:0]
EQ5GC[4:0]
02C
DIGITAL TO ANALOG (DAC) LIMITER
24
18
DAC Limiter 1
DACLIMEN
25
19
DAC Limiter 2
0
DACLIMDCY[3:0]
0
DACLIMTHL[2:0]
DACLIMATK[3:0]
032
DACLIMBST[3:0]
000
NOTCH FILTER
27
1B
Notch Filter High
NFCU
NFCEN
NFCA0[13:7]
000
28
1C Notch Filter Low
NFCU
0
NFCA0[6:0]
000
29
1D Notch Filter High
NFCU
0
NFCA1[13:7]
000
30
1E
NFCU
0
NFCA1[6:0]
000
Notch Filter Low
ALC CONTROL
32
20
ALC CTRL 1
ALCEN
33
21
ALC CTRL 2
ALCZC
ALCHT[3:0]
ALCSL[3:0]
00B
34
22
ALC CTRL 3
ALCM
ALCDCY[3:0]
ALCATK[3:0]
032
35
23
Noise Gate
0
0
0
0
0
ALCMXGAIN[2:0]
0
0
ALCMNGAIN[2:0]
ALCNEN
ALCNTH[2:0]
038
000
PLL CONTROL
36
24
PLL N CTRL
0
0
0
37
25
PLL K 1
0
0
0
38
26
PLL K 2
emPowerAudio™
Datasheet Revision 2.8
0
PLLMCLK
PLLN[3:0]
PLLK[23:18]
00C
PLLK[17:9]
Page 59 of 102
008
093
March 1, 2017
NAU8810
Register
Address
Register Bits
Register Names
DEC HEX
39
27
Default
D8
D7
D6
D5
D4
PLL K 3
D3
D2
D1
D0
PLLK[8:0]
0E9
INPUT, OUTPUT & MIXER CONTROL
40
28
Attenuation CTRL
44
2C Input CTRL
45
2D PGA Gain
47
2F
ADC Boost
49
31
50
0
0
MICBIASV
0
0
0
0
MOUTATT
SPKATT
0
000
0
0
0
0
0
NMICPGA
PMICPGA
003
0
PGAZC
PGAMT
PGAGAIN[5:0]
PGABST
0
Output CTRL
0
0
0
0
32
Mixer CTRL
0
0
0
0
54
36
SPKOUT Volume
0
SPKZC
SPKMT
56
38
MONO Mixer Control
0
0
MOUTMT
PMICBSTGAIN
010
0
0
0
0
100
0
MOUTBST
SPKBST
TSEN
AOUTIMP
002
0
0
0
BYPSPK
DACSPK
001
SPKGAIN[5:0]
0
0
0
039
0
BYPMOUT DACMOUT
001
IBADJ
000
LOW POWER CONTROL
58
3A
Power Management 4
LPIPBST
LPADC
LPSPKD
LPDAC
MICBIASM
TRIMREG
PCM TIME SLOT & ADCOUT IMPEDANCE OPTION CONTROL
59
3B
Time Slot
60
3C ADCOUT Drive
TSLOT[8:0]
PCMTSEN
TRI
PCM8BIT
PUDOEN
PUDPE
000
PUDPS
LOUTR
PCMB
TSLOT[9:8]
020
REGISTER ID
62
3E
Silicon Revision
0
1
1
1
0
1
1
1
1
0EF
63
3F
2-Wire ID
0
0
0
0
1
1
0
1
0
01A
64
40
Additional ID
0
1
1
0
0
1
0
1
0
0CA
65
41
Reserved
1
0
0
1
0
0
1
0
0
124
69
45
High Voltage CTRL
0
0
0
0
MOUTMT
0
HVOPU
0
HVOP
001
70
46
ALC Enhancements 1 ALCTBLSEL ALCPKSEL ALCNGSEL
71
47
ALC Enhancements 2
73
49
Additional IF CTRL
0
75
4B
Power/Tie-off CTRL
0
76
4C
AGC P2P Detector
P2PDET ( ONLY)
000
77
4D
AGC Peak Detector
PDET ( ONLY)
000
78
4E
Control and Status
0
0
AMTCTRL
HVDET
NSGATE
AMUTE
DMUTE
0
FTDEC
000
79
4F
Output tie-off CTRL
MANOUTEN
SBUFH
SBUFL
SNSPK
SPSPK
SMOUT
0
0
0
000
PKLIMEN
emPowerAudio™
Datasheet Revision 2.8
0
0
FSERRVAL[1:0]
LPSPKA
0
ALCGAINL ( ONLY)
1
1
FSERFLSH FSERRENA
0
1
0
NFDLY
DACINMT
0
Page 60 of 102
000
0
0
1
039
PLLLOCKP DACOS256
000
MANVREFH MANVREFM MANVREFL
000
March 1, 2017
NAU8810
13.1. SOFTWARE RESET
Addr
D8
D7
D6
D5
0x00
D4
D3
D2
D1
D0
Default
0x000
RESET (SOFTWARE)
This is device Reset register. Performing a write instruction to this register with any data will reset all the bits in
the register map to default.
13.2. POWER MANAGEMENT REGISTERS
13.2.1.
Addr
Power Management 1
D8
0x01 DCBUFEN
D7
D6
D5
0
0
PLLEN
D4
D3
D2
MICBIASEN ABIASEN IOBUFEN
D1
D0
Default
REFIMP[1:0]
0x000
Name
Buffer for DC
level shifting
Enable
PLL enable
Microphone
Bias
Enable
Analogue
amplifier
bias control
Unused
input/output tie
off buffer enable
Bit
DCBUFEN[8]
PLLEN[5]
MICBIASEN[4]
ABIASEN[3]
IOBUFEN[2]
0
Disable
Disable
Disable
Disable
Disable
1
Enable
(required for
1.5x gain)
Enable
Enable
Enable
Enable
The DCBUFEN[8] address (0x01) is a dedicated buffer for DC level shifting output stages when in 1.5x gain
boost configuration. There are three different reference impedance selections to choose from as follows:
VREF REFERENCE
IMPEDANCE SELECTION
(“R” refers to “R” as shown in Figure3)
REFIMP[1]
REFIMP[0]
Mode
emPowerAudio™
Datasheet Revision 2.8
0
0
Disable
0
1
R = 80 k
1
0
R = 300 k
1
1
R = 3 k
Page 61 of 102
March 1, 2017
NAU8810
13.2.2.
Power Management 2
Addr
D8
D7
D6
D5
D4
D3
D2
D1
D0
Default
0x02
0
0
0
0
BSTEN
0
PGAEN
0
ADCEN
0x000
13.2.3.
Name
Input Boost
Enable
MIC(+/-)
PGA Enable
ADC Enable
Bit
BSTEN[4]
PGAEN[2]
ADCEN[0]
0
Stage Disable
Disable
Disable
1
Stage Enable
Enable
Enable
Power Management 3
Addr
D8
0x03
0
D7
D6
D5
D4
D3
D2
D1
MOUTEN NSPKEN PSPKEN BIASGEN MOUTMXEN SPKMXEN
0
D0
Default
DACEN 0x000
Name
MOUT
Enable
SPKOUTEnable
SPKOUT+
Enable
Bias Enable
MONO Mixer
Enable
Speaker
Mixer Enable
DAC
Enable
Bit
MOUTEN[7]
NSPKEN[6]
PSPKEN[5]
BIASGEN[4]
MOUTMXEN[3]
SPKMXEN[2]
DACEN[0]
0
Disable
Disable
Disable
Disable
Disable
Disable
Disable
1
Enable
Enable
Enable
Enable
Enable
Enable
Enable
13.3. AUDIO CONTROL REGISTERS
13.3.1.
Audio Interface Control
Addr
D8
D7
0x04
BCLKP
FSP
D6
D5
WLEN[1:0]
D4
D3
AIFMT[1:0]
D2
D1
DACPHS ADCPHS
D0
Default
0
0x050
The following table explains the PCM control register bits.
Name
BCLK
Polarity
Frame Clock
Polarity
DAC Data ‘right’ or ‘left’
phases of FRAME clock
ADC Data ‘right’ or ‘left’
phases of FRAME clock
Bit
BCLKP[8]
FSP[7]
DACPHS[2]
ADCPHS[1]
0
Normal
Normal
DAC data appear in ‘left’ phase of
FRAME
ADC data appear in ‘left’ phase of
FRAME
1
Inverted
Inverted
DAC data appears in ‘right’ phase of
FRAME
ADC data appears in ‘right’ phase of
FRAME
There are three different CODEC modes to choose from as follows:
emPowerAudio™
Datasheet Revision 2.8
Page 62 of 102
March 1, 2017
NAU8810
Word Length Selection
Audio Data Format Select
WLEN[6]
WLEN[5]
Bits
AIFMT[4]
AIFMT[3]
Format
0
0
16
0
0
Right
Justified
0
1
20
0
1
Left Justified
1
0
24
1
0
I2 S
1
1
32
1
1
PCM A
13.3.2.
Audio Interface Companding Control
Addr
D8
D7
D6
D5
D4
0x05
0
0
0
CMB8
D3
DACCM[1:0]
D2
D1
ADCCM[1:0]
D0
Default
ADDAP
0x000
The NAU88U10 provides a Digital Loopback ADDAP[0] address (0x05) bit. Setting ADDAP[0] bit to HIGH
enables the loopback so that the ADC data can be fed directly into the DAC input.
Companding Mode 8-bit
word enable
CMB8[5]
0
1
Mode
normal
operation
8-bit operation
emPowerAudio™
Datasheet Revision 2.8
DAC Companding Selection
ADC Companding Select
DACCM[4]
DACCM[3]
Mode
ADCCM[2]
ADCCM[1]
Mode
0
0
Disabled
0
0
Disabled
0
1
Reserved
0
1
Reserved
1
0
µ-Law
1
0
µ-Law
1
1
A-Law
1
1
A-Law
Page 63 of 102
March 1, 2017
NAU8810
13.3.3.
Clock Control Register
Addr
D8
0x06
CLKM
D7
D6
D5
D4
MCLKSEL[2:0]
D3
D2
BCLKSEL[2:0]
Master Clock Selection
MCLKSEL
[7]
MCLKSEL
[6]
MCLKSEL
[5]
0
0
0
0
0
1
0
1
0
0
1
D1
D0
Default
CLKIOEN 0x140
0
Bit Clock Select
BCLKSEL
[4]
BCLKSEL
[3]
BCLKSEL
[2]
0
0
0
0
0
1
2
0
1
0
1
3
0
1
1
8
Mode
1
1.5
Mode
1
(BCLK=MCLK)
2
(BCLK=MCLK/2)
4
1
0
0
4
1
0
0
16
1
0
1
6
1
0
1
32
1
1
0
8
1
1
0
Reserved
1
12
1
1
1
Reserved
1
1
Name
Source of Internal Clock
FRAME and BCLK
Bit
CLKM[8]
CLKIOEN[0]
0
MCLK (PLL Bypassed)
Slave Mode
1
MCLK (PLL Output)
Master Mode
emPowerAudio™
Datasheet Revision 2.8
Page 64 of 102
March 1, 2017
NAU8810
13.3.4.
Audio Sample Rate Control Register
Addr
D8
D7
D6
D5
D4
0x07
0
0
0
0
0
D3
D2
D1
SMPLR[2:0]
D0
Default
SCLKEN
0x000
The Audio sample rate configures only the coefficients for the internal digital filters to match the actual sample
rate. It does not in any way actually set or change the ADC or DAC audio sample rate.
Sample Rate Selection
SMPLR[3]
SMPLR[2]
SMPLR[1]
Mode (Hz)
0
0
0
48 k
0
0
1
32 k
0
1
0
24 k
0
1
1
16 k
1
0
0
12 k
1
0
1
8k
1
1
0
Reserved
1
1
1
Reserved
NAU88U10 provides a slow clock to be used for the zero cross timeout.
Slow Clock Enable
Bit
13.3.5.
SCLKEN[0]
0
MCLK
1
PLL Output (Period 221 * MCLK)
DAC Control Register
Addr
D8
D7
D6
0x0A
0
0
DACMT
D5
D4
DEEMP[1:0]
D3
D2
DACOS AUTOMT
D1
D0
Default
0
DACPL
0x000
Name
Soft Mute Enable
Over Sample Rate
Auto Mute enable
Polarity Invert
Bit
DACMT[6]
DACOS[3]
AUTOMT[2]
DACPL[0]
0
Disable
64x
(Lowest power)
Disable
Normal
1
Enable
128x
(best SNR)
Enable
DAC Output
Inverted
emPowerAudio™
Datasheet Revision 2.8
Page 65 of 102
March 1, 2017
NAU8810
De-emphasis
13.3.6.
DEEMP[5]
DEEMP[4]
Mode
0
0
No de-emphasis
0
1
32kHz sample rate
1
0
44.1kHz sample rate
1
1
48kHz sample rate
DAC Gain Control Register
Addr
D8
0x0B
0
D7
D6
D5
D4
D3
D2
D1
D0
Default
0x0FF
DACGAIN
DAC Gain
DACGAIN[7:0]
Mode (dB)
B7
B6
B5
B4
B3
B2
B1
B0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
Digital
Mute
-127.0
0
0
0
0
0
0
1
0
-126.5
0
0
0
0
0
0
1
1
-126.0
DAC Gain Range -127dB to 0dB @ 0.5 increments
13.3.7.
1
1
1
1
1
1
0
0
-1.5
1
1
1
1
1
1
0
1
-1.0
1
1
1
1
1
1
1
0
-0.5
1
1
1
1
1
1
1
1
0.0
ADC Control Register
Addr
D8
D7
0x0E
HPFEN
HPFAM
Name
High Pass Filter
Enable
Bit
HPFEN[8]
0
1
Disable
Enable
emPowerAudio™
Datasheet Revision 2.8
D6
D5
D4
HPF[2:0]
D3
D2
D1
D0
Default
ADCOS
0
0
ADCPL
0x100
Audio or Application
Mode
Over Sample
Rate
ADC Polarity
HPFAM[7]
ADCOS[3]
ADCPL[0]
64x (Lowest power)
Normal
128x (best SNR)
Inverted
st
Audio (1 order, fc ~ 3.7 Hz)
nd
Application (2
order, fc = HPF)
Page 66 of 102
March 1, 2017
NAU8810
High Pass Filter
fs ( kHz)
HPF[6]
HPF[5]
HPF[4]
B2
B1
B0
0
0
0
0
0
SMPLR=101
SMPLR=100
SMPLR=011
SMPLR=010
8
11.025
12
0
82
113
1
102
141
1
0
131
0
1
1
1
0
0
1
0
1
1
13.3.8.
SMPLR=001
SMPLR=000
16
22.05
24
32
44.1
48
122
82
113
153
102
141
122
82
113
122
153
102
141
153
180
156
131
180
156
131
180
156
163
225
245
204
281
306
163
225
245
163
225
245
204
281
306
204
281
306
1
261
360
392
261
360
392
261
360
392
1
0
327
1
1
408
450
490
327
450
490
327
450
490
563
612
408
563
612
408
563
612
ADC Gain Control Register
Addr
D8
0x0F
0
D7
D6
D5
D4
D3
D2
D1
D0
Default
0x0FF
ADCGAIN
ADC Gain
ADCGAIN[7:0]
Mode (dB)
B7
B6
B5
B4
B3
B2
B1
B0
0
0
0
0
0
0
0
0
Unused
0
0
0
0
0
0
0
1
-127.0
0
0
0
0
0
0
1
0
-126.5
0
0
0
0
0
0
1
1
-126.0
ADC Gain Range -127dB to 0dB @ 0.5 increments
1
1
1
1
1
1
0
0
-1.5
1
1
1
1
1
1
0
1
-1.0
1
1
1
1
1
1
1
0
-0.5
1
1
1
1
1
1
1
1
0.0
emPowerAudio™
Datasheet Revision 2.8
Page 67 of 102
March 1, 2017
NAU8810
13.4.
5-BAND EQUALIZER CONTROL REGISTERS
Address
D8
D7
D6
D5
D4
D3
D2
D1
D0
Default
0x12
EQM
0
EQ1CF[1:0]
EQ1GC[4:0]
0x12C
0x13
EQ2BW
0
EQ2CF[1:0]
EQ2GC[4:0]
0x02C
0x14
EQ3BW
0
EQ3CF[1:0]
EQ3GC[4:0]
0x 02C
0x15
EQ4BW
0
EQ4CF[1:0]
EQ4GC[4:0]
0x02C
0x16
0
0
EQ5CF[1:0]
EQ5GC[4:0]
0x02C
Equalizer Gain
EQ1GC, EQ2GC, EQ3GC, EQ4GC, EQ5GC [4:0]
Mode (dB)
B4
B3
B2
B1
B0
0
0
0
0
0
+12
0
0
0
0
1
+11
:::
:::
:::
:::
:::
:::
0
1
0
1
1
+1
0
1
1
0
0
0
0
1
1
0
1
-1
Equalizer Gain Range -12dB to +12dB @ 1.0 increment
:::
:::
:::
:::
:::
:::
1
0
1
1
1
-11
1
1
0
0
0
-12
1
1
0
0
1
To
1
1
Reserved
1
1
1
Center Frequencies
emPowerAudio™
Datasheet Revision 2.8
B1
B0
EQ2CF[6:5]
EQ3CF[6:5]
EQ4CF[6:5]
0
0
230
650
1.8 k
0
1
300
850
2.4 k
1
0
385
1.1 k
3.2 k
1
1
500
1.4 k
4.1 k
Page 68 of 102
March 1, 2017
NAU8810
Cut-off Frequencies
EQ5CF[6:5
]
0
80
5.3 k
1
105
6.9 k
1
0
135
9.0 k
1
1
175
11.7 k
B0
0
0
Bandwidth Control
Equalizer Path
EQ2BW – EQ4BW
EQM[8]
0
Narrow bandwidth
ADC path
1
Wide bandwidth
DAC path
Bit
13.5.
EQ1CF[6:5]
B1
DIGITAL TO ANALOG CONVERTER (DAC) LIMITER REGISTERS
Addr
D8
D7
0x18
DACLIMEN
0x19
0
D6
D5
D4
D3
DACLIMDCY[3:0]
0
DACLIMTHL[2:0]
DAC Limiter Decay time (per 6dB gain change) for 44.1
kHz sampling. Note that these will scale with sample
rate
D2
D1
D0
Default
DACLIMATK[3:0]
0x032
DACLIMBST[3:0]
0x000
DAC Limiter Attack time (per 6dB gain change) for 44.1
kHz sampling. Note that these will scale with sample rate
DACLIMDCY[3:0]
DACLIMATK[3:0]
B3
B2
B1
B0
Decay Time
B3
B2
B1
B0
Attack Time
0
0
0
0
544.0 us
0
0
0
0
68 us
0
0
0
1
1.1 ms
0
0
0
1
136 us
0
0
1
0
2.2 ms
0
0
1
0
272 us
0
0
1
1
4.4 ms
0
0
1
1
544 us
0
1
0
0
8.7 ms
0
1
0
0
1.1 ms
0
1
0
1
17.4 ms
0
1
0
1
2.2 ms
0
1
1
0
35.0 ms
0
1
1
0
4.4 ms
0
1
1
1
69.6 ms
0
1
1
1
8.7 ms
1
0
0
0
139.0 ms
1
0
0
0
17.4 ms
1
0
0
1
278.5 ms
1
0
0
1
35 ms
1
0
1
0
557.0 ms
1
0
1
0
69.6 ms
1
0
1
1
1
0
1
1
To
1
1
1.1 s
1
To
1
emPowerAudio™
Datasheet Revision 2.8
1
Page 69 of 102
1
139 ms
1
1
March 1, 2017
NAU8810
DAC Limiter volume Boost (can be used as
a
standalone volume Boost when
DACLIMEN=0)
DACLIMBST[3:0]
Boost
(dB)
B3
B2
B1
B0
DAC Limiter Programmable signal threshold level
(determines level at which the limiter starts to
operate)
DACLIMTHL[3:0]
B2
B1
B0
Threshold
(dB)
0
0
0
-1
0
0
0
0
0
0
0
1
-2
0
0
0
1
+1
0
1
0
-3
0
0
1
0
+2
0
1
1
-4
0
0
1
1
+3
1
0
0
-5
0
1
0
0
+4
1
0
1
0
1
0
1
+5
0
1
1
0
+6
0
1
1
1
+7
1
0
0
0
+8
1
0
0
1
+9
To
1
-6
1
1
1
0
1
0
+10
Bit
DAC Digital Limiter
DACLIMEN[8]
1
0
1
1
+11
0
Disabled
1
1
0
0
+12
1
Enabled
1
1
0
1
1
1
1
1
Reserved
To
13.6. NOTCH FILTER REGISTERS
Addr
D8
D7
0x1B
NFCU
NFCEN
0x1C
NFCU
0x1D
NFCU
0x1E
NFCU
D6
D5
D4
D3
D2
D1
D0
Default
NFCA0[13:7]
0x000
0
NFCA0[6:0]
0x000
0
NFCA1[13:7]
0x000
0
NFCA1[6:0]
0x000
The Notch Filter is enabled by setting NFCEN[7] address (0x1B) bit to HIGH. The coefficients, A0 and A1, should
be converted to 2’s complement numbers to determine the register values. A0 and A1 are represented by the
register bits NFCA0[13:0] and NFCA1[13:0]. Since there are four register of coefficients, a Notch Filter Update bit
is provided so that the coefficients can be updated simultaneously. NFCU[8] is provided in all registers of the
Notch Filter coefficients but only one bit needs to be toggled for LOW – HIGH – LOW for an update. If any of the
NFCU[8] bits are left HIGH then the Notch Filter coefficients will continuously update. An example of how to
calculate is provided in the Notch Filter section.
emPowerAudio™
Datasheet Revision 2.8
Page 70 of 102
March 1, 2017
NAU8810
Name
A0
A1
Coefficient
2fb
1 tan
2fs
2fb
1 tan
2fs
2f
1 A0 x cos c
fs
Notation
Register Value (DEC)
fc = center frequency (Hz)
fb = -3dB bandwidth (Hz)
fs = sample frequency
(Hz)
NFCA0 = -A0 x 213
NFCA1 = -A1 x 212
(then convert to 2’s
complement)
13.7. AUTOMATIC LEVEL CONTROL REGISTER
13.7.1.
ALC1 REGISTER
Addr
D8
D7
D6
0x20
ALCEN
0
0
D5
D4
D3
ALCMXGAIN[2:0]
ALCMXGAIN[2:0]
B1
B0
0
0
0
0
0
1
0
1
0
1
1
D1
D0
ALCMNGAIN[2:0]
Maximum Gain
B2
D2
0x038
Minimum Gain
ALCMNGAIN[2:0]
Mode
Mode
B2
B1
B0
-6.75dB
0
0
0
-12dB
-0.75dB
0
0
1
-6dB
0
+5.25dB
0
1
0
0dB
1
+11.25dB
0
1
1
+6dB
0
0
+17.25dB
1
0
0
+12dB
1
0
1
+23.25dB
1
0
1
+18dB
1
1
0
+29.25dB
1
1
0
+24dB
1
1
1
+35.25dB
1
1
1
+30dB
emPowerAudio™
Datasheet Revision 2.8
Default
Name
ALC Enable
Bit
ALCEN[8]
0
Disabled (PGA gain set by PGAGAIN
register bits)
1
Enabled
(ALC controls PGA gain)
Page 71 of 102
March 1, 2017
NAU8810
13.7.2.
ALC2 REGISTER
Addr
D8
0x21
ALCZC
D7
D6
D5
D4
D3
D2
ALCHT[3:0]
D0
Default
0x00B
ALCSL[3:0]
ALC TARGET – sets signal level at ADC input
ALC HOLD TIME before gain is increased.
ALCHT[3:0]
D1
ALCSL[3:0]
B7
B6
B5
B4
ALC Hold
Time (sec)
B3
B2
B1
B0
ALC Target
Level (dB)
0
0
0
0
0
0
0
0
0
-28.5 fs
0
0
0
1
2 ms
0
0
0
1
-27 fs
0
0
1
0
4 ms
0
0
1
0
25.5 fs
ALC Target Level Range
-28.5dB to -6dB @ 1.5dB increments
Time Doubles with every increment
1
0
0
0
256 ms
1
0
1
1
-12 fs
1
0
0
1
512 ms
1
1
0
0
-10.5 fs
1
0
1
0
1
1
0
1
-9 fs
1
1
1
0
-7.5 fs
1
1
1
1
-6 fs
To
1
1
1s
1
1
Name
ALC Zero Crossing
Detect
Bit
ALCZC[8]
0
Disabled
1
Enabled
It is recommended that zero crossing should not be used in conjunction with the ALC or Limiter functions
emPowerAudio™
Datasheet Revision 2.8
Page 72 of 102
March 1, 2017
NAU8810
13.7.3.
ALC3 REGISTER
Addr
D8
D7
0x22
ALCM
D6
D5
D4
D3
D2
ALCDCY[3:0]
D1
D0
Default
0x032
ALCATK[3:0]
ALC DECAY TIME
ALCDCY[3:0]
ALCM = 0 (Normal Mode)
ALCM = 1 (Limiter Mode)
B3
B2
B1
B0
Per Step
Per 6dB
90% of
Range
Per Step
Per 6dB
90% of
Range
0
0
0
0
500 us
4 ms
28.78 ms
125 us
1 ms
7.2 ms
0
0
0
1
1 ms
8 ms
57.56 ms
250 us
2 ms
14.4 ms
0
0
1
0
2 ms
16 ms
115 ms
500 us
4 ms
28.8 ms
Time doubles with every increment
1
0
0
0
128 ms
1s
7.37 s
32 ms
256 ms
1.8 s
1
0
0
1
256 ms
2s
14.7 s
64 ms
512 ms
3.7 s
1
0
1
0
512 ms
4s
29.5 s
128 ms
1s
7.37 s
To
1
1
1
1
ALC ATTACK TIME
ALCATK[3:0]
ALCM = 0 (Normal Mode)
ALCM = 1 (Limiter Mode)
90% of
Range
Per Step
Per 6dB
90% of
Range
B3
B2
B1
B0
Per Step
Per 6dB
0
0
0
0
125 us
1 ms
7.2 ms
31 us
248 us
1.8 ms
0
0
0
1
250 us
2 ms
14.4 ms
62 us
496 us
3.6 ms
0
0
1
0
500 us
4 ms
28.85 ms
124 us
992 us
7.15 ms
1
0
0
0
26.5 ms
256 ms
1.53 s
7.9 ms
63.2 ms
455.8 ms
1
0
0
1
53 ms
512 ms
3.06 s
15.87 ms
127 ms
916 ms
1
0
1
0
128 ms
1s
7.89 s
31.7ms
254 ms
1.83 s
1
1
Time doubles with every increment
To
1
1
emPowerAudio™
Datasheet Revision 2.8
Page 73 of 102
March 1, 2017
NAU8810
13.8. NOISE GAIN CONTROL REGISTER
Addr
D8
D7
D6
D5
D4
D3
0x23
0
0
0
0
0
ALCNEN
Noise Gate Enable
D2
D1
D0
ALCNTH[2:0]
Default
0x000
Noise Gate Threshold
Bit
ALCNEN[3]
0
Disabled
B2
B1
B0
1
Enabled
0
0
0
-39 dB
0
0
1
-45 dB
0
1
0
-51 dB
0
1
1
-57 dB
1
0
0
-63 dB
1
0
1
-69 dB
1
1
0
-75 dB
1
1
1
-81 dB
ALCNTH[2:0]
Mode
emPowerAudio™
Datasheet Revision 2.8
Page 74 of 102
March 1, 2017
NAU8810
13.9. PHASE LOCK LOOP (PLL) REGISTERS
13.9.1.
PLL Control Registers
Addr
D8
D7
D6
D5
D4
0x24
0
0
0
0
PLLMCLK
D3
D2
D0
Default
0x008
PLLN[3:0]
PLL Integer
PLL Clock
PLLN[3:0]
B3
B2
B1
B0
0
0
0
1
Bit
Frequency
Ratio
PLLMCLK[4]
0
MCLK not divided
1
Divide MCLK by 2 before input
PLL
Not Valid
To
0
1
0
0
0
1
0
1
5
0
1
1
0
6
0
1
1
1
7
1
0
0
0
8
1
0
0
1
9
1
0
1
0
10
1
0
1
1
11
1
1
0
0
12
1
1
0
1
13
1
1
1
0
1
1
1
1
13.9.2.
D1
Not Valid
Phase Lock Loop Control (PLL) Registers
Addr
D8
D7
D6
0x25
0
0
0
D5
D4
D3
D2
PLLK[23:18]
D1
D0
Default
0x00C
0x26
PLLK[17:9]
0x093
0x27
PLLK[8:0]
0x0E9
Fractional (K) part of PLLK1 – PLLK3 input/output frequency ratio
emPowerAudio™
Datasheet Revision 2.8
Page 75 of 102
March 1, 2017
NAU8810
13.10.
INPUT, OUTPUT, AND MIXERS CONTROL REGISTER
13.10.1.
Attenuation Control Register
Addr
D8
D7
D6
D5
D4
D3
0x28
0
0
0
0
0
0
D2
D1
MOUTATT SPKATT
D0
Default
0
0x000
D0
Default
Attenuation Control
Attenuation control for bypass path (output of
input boost stage) to speaker mixer and MONO
mixer input
Name
MOUTATT[2]
Bit
13.10.2.
Addr
0x2C
SPKATT[1]
0
0 dB
0 dB
1
-10 dB
-10 dB
Input Signal Control Register
D8
D7
MICBIASV
D6
D5
D4
D3
D2
0
0
0
0
0
D1
NMICPGA PMICPGA 0x003
MICN to input PGA
negative terminal
Input PGA amplifier
positive terminal to
MIC+ or VREF
Bit
NMICPGA[1]
PMICPGA[0]
0
MICN not connected to
input PGA
Input PGA Positive
terminal to VREF
1
MICN to input PGA
Negative terminal.
Input PGA Positive
terminal to MICP
through variable resistor
Microphone Bias Voltage Control
MICBIASV[8:7]
Address (0x2C)
MICBIASM[4] = 0
Address (0x28)
MICBIASM[4] = 1
Address (0x28)
0
0
0.9* VDDA
0.85* VDDA
0
1
0.65* VDDA
0.60* VDDA
1
0
0.75* VDDA
0.70* VDDA
1
1
0.50* VDDA
0.50* VDDA
emPowerAudio™
Datasheet Revision 2.8
Page 76 of 102
March 1, 2017
NAU8810
13.10.3.
PGA Gain Control Register
Addr
D8
D7
D6
D5
0x2D
0
PGAZC
PGAMT
D4
D3
D2
D1
PGAGAIN[5:0]
D0
Default
0x010
Programmable Gain Amplifier Gain
PGAGAIN[5:0]
B5
B4
B3
B2
B1
B0
Gain
0
0
0
0
0
0
-12.00 dB
0
0
0
0
0
1
-11.25 dB
0
0
0
0
1
0
-10.50 dB
:::
:::
:::
:::
:::
:::
:::
0
0
1
1
1
1
-0.75 dB
0
1
0
0
0
0
0 dB
0
1
0
0
0
1
+0.75 dB
PGA Gain Range -12dB to +35.25dB @ 0.75
increment
:::
:::
:::
:::
:::
:::
:::
1
1
1
1
0
1
33.75
1
1
1
1
1
0
34.50
1
1
1
1
1
1
35.25
PGA Zero Cross Enable
Mute Control for PGA
Bit
PGAZC[7]
PGAMT[6]
0
Update gain when gain
register changes
Normal Mode
st
1
emPowerAudio™
Datasheet Revision 2.8
Update gain on 1 zero
cross after gain register
write
Page 77 of 102
PGA Muted
March 1, 2017
NAU8810
13.10.4.
ADC Boost Control Registers
Addr
D8
D7
0x2F
PGABST
0
D6
D5
D4
D3
D2
D1
D0
Default
0
0
0
0
0x100
D1
D0
Default
PMICBSTGAIN
MIC+ pin to the input Boost Stage
(NB, when using this path set
PMICPGA=0):
PMICBSTGAIN[2:0]
13.10.5.
Gain (dB)
B2
B1
B0
0
0
0
0
0
1
Path
Disconnected
-12
0
1
0
-9
0
1
1
-6
1
0
0
-3
1
0
1
0
1
1
0
+3
1
1
1
+6
Name
Input Boost
Bit
PGABST[8]
0
PGA output has +0dB gain through input Boost stage
1
PGA output has +20dB gain through input Boost stage
Output Register
Addr
D8
D7
D6
D5
D4
0x31
0
0
0
0
0
D3
D2
MOUTBST SPKBST
TSEN
AOUTIMP 0x002
MONO Output Boost
Stage
Speaker Output Boost
Stage
Thermal Shutdown
Analog Output Resistance
Bit
MOUTBST[3]
SPKBST[2]
TSEN[1]
AOUTIMP[0]
0
(1.0 x VREF) Gain Boost
(1.0 x VREF) Gain Boost
Disabled
~1kΩ
1
(1.5 x VREF) Gain Boost
(1.5 x VREF) Gain Boost
Enabled
~30 kΩ
emPowerAudio™
Datasheet Revision 2.8
Page 78 of 102
March 1, 2017
NAU8810
13.10.6.
Speaker Mixer Control Register
Addr
D8
D7
D6
D5
D4
D3
D2
0x32
0
0
0
0
0
0
0
13.10.7.
D1
D0
Default
BYPSPK DACSPK 0x001
Bypass path (output of
Boost stage) to Speaker
Mixer
DAC to Speaker Mixer
Bit
BYPSPK[1]
DACSPK[0]
0
Disconnected
Disconnected
1
Connected
Connected
Speaker Gain Control Register
Addr
D8
D7
D6
0x36
0
SPKZC
SPKMT
D5
D4
D3
D2
D1
D0
Default
0x039
SPKGAIN[5:0]
Speaker Gain
SPKGAIN[5:0]
B5
B4
B3
B2
B1
B0
Gain (dB)
0
0
0
0
0
0
-57.0
0
0
0
0
0
1
-56.0
0
0
0
0
1
0
-55.0
:::
:::
:::
:::
:::
:::
:::
1
1
1
0
0
0
-1.0
1
1
1
0
0
1
0.0
1
1
0
1
0
+1.0
1
Speaker Gain Range -57 dB to +6 dB @ +1
increment
:::
:::
:::
:::
:::
:::
:::
1
1
1
1
0
1
+4.0
1
1
1
1
1
0
+5.0
1
1
1
1
1
1
+6.0
Speaker Gain Control Zero Cross
Speaker Output
Bit
SPKZC[7]
SPKMT[6]
0
Change Gain on Zero Cross
ONLY
Speaker Enabled
1
Change Gain Immediately
Speaker Muted
emPowerAudio™
Datasheet Revision 2.8
Page 79 of 102
March 1, 2017
NAU8810
13.10.8.
MONO Mixer Control Register
Addr
D8
D7
D6
D5
D4
D3
D2
0x38
0
0
MOUTMXMT
0
0
0
0
D1
D0
Default
BYPMOUT DACMOUT 0x001
MOUT Mute
Bypass path (output of
Boost Stage) to MONO
Mixer
DAC to
MONO Mixer
Bit
MOUTMXMT[6]
BYPMOUT[1]
DACMOUT[0]
0
Not Muted
Disconnected
Disconnected
1
Muted
Connected
Connected
During mute, the MONO output will output VREF that can be used as a DC reference for a headphone out.
13.10.9.
Addr
Power Management 4
D8
D7
0x3A LPIPBST LPADC
B1
D6
D5
LPSPKD
D4
D3
LPDAC MICBIASM
D2
D1
TRIMREG[3:2]
D0
Default
0x000
IBADJ[1:0]
Trim Output Regulator (V)
Adjust Master Bias of the Analog Portion
TRIMREG[3:2]
IBADJ[1:0]
B0
0
0
1.800
Default Current Consumption
0
1
1.610
25% Current Increase from Default
1
0
1.400
14% Current Decrease from Default
1
1
1.218
25% Current Decrease from Default
Trim regulator bits can be used only when VDDD 0.546*fs
-60
Group Delay
dB
21/fs
ADC High Pass Filter
High Pass Filter
Corner Frequency
-3dB
3.7
-0.5dB
10.4
-0.1dB
21.6
Hz
DAC Filter
+/- 0.035dB
0
0.454*fs
Pass band
-6dB
0.5*fs
Pass band Ripple
+/-0.035
Stop band
Stop band
Attenuation
dB
0.546*fs
f > 0.546*fs
-55
Group Delay
dB
29/fs
Table 57 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
emPowerAudio™
Datasheet Revision 2.8
Page 96 of 102
March 1, 2017
NAU8810
Figure 44: DAC Filter Frequency Response
Figure 45: ADC Filter Frequency Response
Figure 46: DAC Filter Ripple
Figure 47: ADC Filter Ripple
emPowerAudio™
Datasheet Revision 2.8
Page 97 of 102
March 1, 2017
NAU8810
17. TYPICAL APPLICATION
Figure 48: Application Diagram For 20-Pin QFN
Note 1: All non-polar capacitors are assumed to be low ESR type parts, such as with MLC construction or similar.
If capacitors are not low ESR, additional 0.1uF and/or 0.01uF capacitors may be necessary in parallel
with the bulk 4.7uF capacitors on the supply rails.
Note 2: Load resistors to ground on outputs may be helpful in some applications to insure a DC path for the
output capacitors to charge/discharge to the desired levels. If the output load is always present and the
output load provides a suitable DC path to ground, then the additional load resistors may not be
necessary. If needed, such load resistors are typically a high value, but a value dependent upon the
application requirements.
Note 3: To minimize pops and clicks, large polarized output capacitors should be a low leakage type.
Note 4: Depending on the microphone device and PGA gain settings, common mode rejection can be improved
by choosing the resistors on each node of the microphone such that the impedance presented to any
noise on either microphone wire is equal.
emPowerAudio™
Datasheet Revision 2.8
Page 98 of 102
March 1, 2017
NAU8810
18. PACKAGE SPECIFICATION
emPowerAudio™
Datasheet Revision 2.8
Page 99 of 102
March 1, 2017
NAU8810
19. ORDERING INFORMATION
Nuvoton Part Number Description
NAU88U10Y G
Package Material:
G
=
Pb-free Package
Package Type:
Y
=
20-Pin QFN Package
Feature:
U
=
emPowerAudio™
Datasheet Revision 2.8
AEC-Q100
Page 100 of 102
March 1, 2017
NAU8810
20. VERSION HISTORY
VERSION
DATE
1.0
September 2010
1.1
October 2010
1.2
1.3
1.4
1.5
January 2011
October 2013
Nov. 7, 2013
Nov. 7, 2013
PAGE
Preliminary Revision
95
Updated Applications Diagram
57
Corrected Register 0x38 Register name
73
Improved description of Mic Bias set up
89
Added TMCLKH and TMCLKL parameters to table
85
Corrected 2 wire timing diagram
14
Corrected Digital I/O voltage levels from DCVDD to DBVDD
11
Modify operating condition from VDDA≥VDDC to VDDA≥VDDB.
11
Modify the VDDSPK operating condition
95
Modify Figure 48 (Application Diagram For 20-Pin QFN)
Modify Figure 48, replace the VSSA with the symbol of analog
95
12 – 14
1.6
1.7
Jan. 15, 2014
Mar. 27, 2014
DESCRIPTION
ground
An additional remark of VDDSPK boost mode
43
Modify Figure 23 (Byte Write Sequence)
44
Modify Figure 24 (2-Wire Read Sequence)
11-14,
Modified VDDB and VDDC to VDDD
51, 53,
Corrected headphone full scale output
54,13,89
Corrected rising/falling time specification of I2S
3
Pin 11 and 12 functionalities are updated.
23
Added more descriptions to figure 8.
Nov,2014
85
Corrected Tsdios setup time
2.0
Jan,2015
1 and 98
2.1
May 2015
98
2.2
July 2015
23,65
2.3
Sep,2015
81
Added Reg0x45[5] for SPKMOUT
2.4
Oct, 2015
37
Added 12.6.3 session for differential output configuration
2.5
Feb, 2016
1
Updated AEC-Q100 description
2.6
March 2016
35
Add Important Notice
43
Revise f1 equation from * to /
82
Add Silicon Revision ID
All
updated part number
1.8
July 2, 2014
1.9
2.7
2.8
June,2016
March, 2017
emPowerAudio™
Datasheet Revision 2.8
Updated AEC-Q100 description note and ordering information
Correct a typing error. Modify “contract “ to “contact”
Change 3.7KHz to 3.7Hz
Page 101 of 102
March 1, 2017
NAU8810
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.
emPowerAudio™
Datasheet Revision 2.8
Page 102 of 102
March 1, 2017
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