LM4937

LM4937 Audio Sub-System with OCL Stereo Headphone Output and RF Suppression February 2007 LM4937 Audio Sub-System with OCL Stereo Headphone Output and RF Suppression General Description The LM4937 is an integrated audio sub-system designed for mono voice, stereo music cell phones connecting to base band processors with mono differential analog voice paths. Operating on a 3.3V supply, it combines a mono speaker amplifier delivering 520mW into an 8Ω load, a stereo headphone amplifier delivering 36mW per channel into a 32Ω load, and a mono earpiece amplifier delivering 55mW into a 32Ω load. It integrates the audio amplifiers, volume control, mixer, and power management control all into a single package. In addition, the LM4937 routes and mixes the single-ended stereo and differential mono inputs into multiple distinct output modes. The LM4937 features an I2S serial interface for full range audio and an I2C or SPI compatible interface for control. The full range music path features an SNR of 85dB with an 18-bit 48kHz input. Boomer audio power amplifiers are designed specifically to provide high quality output power with a minimal amount of external components. Key Specifications ■ POUT, BTL, 8Ω, 3.3V, 1% ■ POUT H/P, 32Ω, 3.3V, 1% ■ POUT Mono Earpiece, 32Ω, 1% ■ Shutdown current ■ SNR (DAC + Amplifier) 520mW (typ) 36mW (typ) 55mW (typ) 0.6µA (typ) 85dB (typ) Features ■ ■ ■ ■ ■ ■ ■ 18-bit stereo DAC Multiple distinct output modes Mono speaker amplifier Stereo headphone amplifier Mono earpiece amplifier Differential mono analog input Independent loudspeaker, headphone and mono earpiece volume controls ■ I2C/SPI (selectable) compatible interface ■ Ultra low shutdown current ■ Click and Pop Suppression circuit Applications ■ Cell Phones ■ PDAs Boomer® is a registered trademark of National Semiconductor Corporation. © 2007 National Semiconductor Corporation 202020 www.national.com LM4937 Block Diagram 20202001 FIGURE 1. Audio Sub-System Block Diagram with OCL HP Outputs (HP outputs may also be configured as cap-coupled) Connection Diagrams 36 – Bump Micro SMD 20202058 Top View (Bump Side Down) Order Number LM4937TL See NS Package Number TLA36LVA www.national.com 2 LM4937 36 – Bump Micro SMD Top Marking Drawing 20202002 Top View XY — 2 Digit Date Code TT — Die Traceability G — Boomer Family I1 — LM4937TL 3 www.national.com LM4937 Pin Descriptions Pin A1 A2 A3 A4 A5 A6 B1 B2 B3 B4 B5 B6 C1 C2 C3 C4 C5 C6 D1 D2 D3 D4 D5 D6 E1 E2 E3 E4 E5 E6 F1 F2 F3 F4 F5 F6 Pin Name DGND MCLK I2S_WS SDA/SDI DVDD VDD_IO PLL_VDD I2S_SDATA I2S_CLK GPIO I2C_VDD SDL/SCK PLL_GND PLL_OUT PLL_IN ADDR/ENB BYPASS AVDD AGND AGND NC MODE RHP CHP DIFF_ LIN RIN NC LHP AGND DIFF+ EP_ EP+ LSAVDD LS+ A A A A A A A A O P I O O O P O D A A A A A I O O I I I Digital/ Analog D D D D D D D D D D D D D D D D A A A A I/O, Power P I I/O I/O P P P I I/O O P I P O I I I P P P Description DIGITAL GND MASTER CLOCK I2S WORD SELECT I2C SDA OR SPI SDI DIGITAL SUPPLY VOLTAGE I/O SUPPLY VOLTAGE PLL SUPPLY VOLTAGE I2S SERIAL DATA INPUT I2S CLOCK SIGNAL TEST PIN (MUST BE LEFT FLOATING) I2C SUPPLY VOLTAGE I2C_SCL OR SPI_SCK PLL GND PLL FILTER OUTPUT PLL FILTER INPUT I2C ADDRESS OR SPI ENB DEPENDING ON MODE HALF-SUPPLY BYPASS ANALOG SUPPLY VOLTAGE ANALOG GND ANALOG GND NO CONNECT SELECTS BETWEEN I2C OR SPI CONTROL RIGHT HEADPHONE OUTPUT HEADPHONE CENTER PIN OUTPUT (1/2 VDD or GND) ANALOG NEGATIVE DIFFERENTIAL INPUT ANALOG LEFT CHANNEL INPUT ANALOG RIGHT CHANNEL INPUT NO CONNECT LEFT HEADPHONE OUTPUT ANALOG GND ANALOG POSITIVE DIFFERENTIAL INPUT MONO EARPIECEMONO EARPIECE+ LOUDSPEAKER OUTANALOG SUPPLY VOLTAGE LOUD SPEAKER OUT+ www.national.com 4 LM4937 Absolute Maximum Ratings (Notes 1, 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Analog Supply Voltage Digital Supply Voltage Storage Temperature Input Voltage Power Dissipation (Note 3) ESD Susceptibility (Note 4) ESD Susceptibility (Note 5) Junction Temperature 6.0V 6.0V -65°C to +150°C -0.3V to VDD +0.3V Internally Limited 2000V 200V 150°C Thermal Resistance  θJA (TLA36) See AN-1279 100°C/W Operating Ratings Temperature Range TMIN ≤ TA ≤ TMAX Supply Voltage −40°C ≤ TA ≤ +85°C 2.7V ≤ AVDD ≤ 5.5V 2.4V ≤ I2CVDD ≤ 4.0V 2.7V ≤ DVDD ≤ 4.0V Audio Amplifier Electrical Characteristics AVDD = 3.0V, DVDD = 3.0V Symbol Parameter Conditions LM4937 (Notes 1, 2) The following specifications apply for the circuit shown in Figure 1 with all programmable gain set at 0dB, unless otherwise specified. Limits apply for TA = 25°C. Typical Limits (Note 6) (Notes 7, 8) VIN = 0, No Load All Amps On + DAC, OCL (Note 11) Headphone Mode Only, OCL IDD Supply Current Mono Loudspeaker Mode Only (Note 11) Mono Earpiece Speaker Mode Only D_6 = 0 (register 01h) D_6 = 1 DAC Off, All Amps On (OCL) (Note 11) ISD Shutdown Current Speaker; THD = 1%; f = 1kHz, 8Ω BTL PO Output Power Headphone; THD = 1%; f = 1kHz, 32Ω SE Earpiece; THD = 1%; f = 1kHz, 32Ω BTL VFS DAC Full Scale DAC Output Speaker; PO = 200mW; f = 1kHz, 8Ω BTL THD+N Total Harmonic Distortion Headphone; PO = 10mW; f = 1kHz, 32Ω SE Earpiece; PO = 20mW; f = 1kHz, 32Ω BTL Speaker VOS ∈O PSRR Offset Voltage Output Noise Power Supply Rejection Ratio Earpiece Headphone (OCL) A = weighted; 0dB gain; See Table 1 f = 217Hz; Vripple = 200mVP-P CB = 2.2μF; See Table 2 Xtalk TWU CMRR Crosstalk Wake-Up Time Common-Mode Rejection Ratio Headphone; PO= 10mW f = 1kHz; OCL CB = 2.2μF, CD6 = 0 CB = 2.2μF, CD6 = 1 f = 217Hz, VRMS = 200mVpp 5 Units (Limits) 14 4.6 7 3.7 3.3 10 0.6 420 27 45 2.4 0.04 0.01 0.04 10 8 8 Table 1 19 6.25 11.5 5 15.5 2 370 24 40 mA (max) mA (max) mA (max) mA (max) mA mA (max) μA (max) mW (min) mW (min) mW (min) Vpp % % % 55 50 40 mV (max) mV (max) mV (max) Table 2 –60 35 85 56 dB ms (max) ms (max) dB www.national.com LM4937 Audio Amplifier Electrical Characteristics AVDD = 5.0V, DVDD = 3.3V Symbol Parameter Conditions LM4937 Typical (Note 6) VIN = 0, No Load All Amps On + DAC, OCL (Note 11) IDD Supply Current Headphone Mode Only (OCL) Mono Loudspeaker Mode Only (Note 11) Mono Earpiece Mode Only (Note 11) DAC Off, All Amps On (OCL) (Note 11) ISD Shutdown Current Speaker; THD = 1%; f = 1kHz, 8Ω BTL PO Output Power Headphone; THD = 1%; f = 1kHz, 32Ω SE Earpiece; THD = 1%; f = 1kHz, 32Ω BTL VFS DAC Full Scale DAC Output Speaker; PO = 500mW; f = 1kHz, 8Ω BTL THD+N Total Harmonic Distortion Headphone; PO = 30mW; f = 1kHz, 32Ω SE Earpiece; PO = 40mW; f = 1kHz, 32Ω BTL; CD4 = 0 Speaker VOS ∈O PSRR Offset Voltage Output Noise Power Supply Rejection Ratio Earpiece HP (OCL) A = weighted; 0dB gain; See Table 1 f = 217Hz; Vripple = 200mVP-P CB = 2.2μF; See Table 3 Xtalk TWU Crosstalk Wake-Up Time Headphone; PO= 15mW f = 1kHz; OCL CB = 2.2μF, CD6 = 0 CB = 2.2μF, CD6 = 1 (Notes 1, 2) The following specifications apply for the circuit shown in Figure 1 with all programmable gain set at 0dB, unless otherwise specified. Limits apply for TA = 25°C. Limits (Notes 7, 8) Units (Limits) 17.5 5.8 11.6 5 12.9 1.6 1.25 80 175 2.4 0.03 0.01 0.04 10 8 8 Table 1 Table 3 –56 45 130 mA (max) mA (max) mA (max) mA (max) mA (max) μA (max) mW (min) mW (min) mW (min) Vpp % % % mV mV mV dB ms ms www.national.com 6 LM4937 Volume Control Electrical Characteristics Symbol Parameter (Notes 1, 2) The following specifications apply for 3V ≤ AVDD ≤ 5V and 2.7V ≤ DVDD ≤ 4.0V, unless otherwise specified. Limits apply for TA = 25°C. Conditions LM4937 Typical (Note 6) Limits (Notes 7, 8) –7 –5 15.5 14.5 –13 –11 9.5 8.5 –59 –53 4.5 5.5 Units (Limits) Stereo Analog Inputs PreAmp Gain Setting Range PGR Differential Mono Analog Input PreAmp Gain Setting Range minimum gain setting maximum gain setting minimum gain setting maximum gain setting minimum gain setting maximum gain setting –6 15 –12 9 –56 +5 0.3 dB (min) dB (max) dB (max) dB (min) dB (min) dB (max) dB (max) dB (min) dB (min) dB (max) dB (min) dB (max) dB VCR Output Volume Control for Loudspeaker, Headphone Output, or Earpiece Output Stereo Channel to Channel Gain Mismatch Mute Attenuation ΔACH-CH AMUTE RINPUT Vin = 1Vrms, Gain = 0dB with load Headphone