1FEATURES

23• 18-bit 44.1kHz or 48kHz Stereo DAC

• 16-bit 8kHz , 12kHz , 16kHz, or 24kHz Voice-

Band Codec

• PLL for Operation from Common System

Clocks

• Either I2C or SPI Compatible Serial Interface

• I2S Digital Audio Data Serial Interface

• PCM Voice Audio Data Serial Interface

• Differential Analog Microphone Input

• 26mW/Channel Stereo Headphone Amplifier

• 570mW Mono High Efficiency BTL 8Ω

Amplifier

• 32-step Volume Control for Audio Output

Amplifiers with 1.5dB Step Size.

• Unity-Gain Stable Headphone Amplifiers

• No Snubber Networks or Bootstrap Capacitors

are Required by the Headphone or Hands-Free

Amplifiers

• Adjustable Digital Side-Tone Attenuation

• 16-step Volume Control for Microphone

Preamp with 2dB Step Size

• Configurable GPIO/Status Port

• Available in the 42 bump DSBGA Package

APPLICATIONS

• 2.5 and 3G Mobile Phones and Multimedia

Terminals

• PDAs, Internet Appliances and Portable

Gaming

• Portable DVD/CD/AAC/MP3 Players

• Digital Cameras and Toys

KEY SPECIFICATIONS

• PLS OUT at AVDD = 5V, 8Ω

– 1% THD+N, 1.1W (Typ)

• PLS OUT at AVDD = 3.3V, 8Ω

– 1% THD+N, 570mW (Typ)

• PH/P OUT at AVDD = 5V & AVDD = 3.3V, 32Ω

– 1% THD+N, 26mW (Typ)

• Supply Voltage Range

– DVDD, 2.7V to 4.0V

– AVDD, 2.7V to 5.0V(1)

• Shutdown Current, 1.1μA

• PSRR at 217Hz, AVDD = 3V, 62dB (Typ)

• SNR (Voice Codec), 75dB (Typ)

• SNR (Audio DAC), 86dB (Typ)

DESCRIPTION

The LM4931 is an integrated audio subsystem that

supports voice and digital audio functions. The

LM4931 includes a high quality stereo DAC, voice

band codec, a stereo headphone amplifier and a

high-power high efficiency mono speaker amplifier. It

is primarily designed for demanding applications in

mobile phones and other portable devices.

The LM4931 features an I2S serial interface for full

range audio, a 16-bit PCM bi-directional serial

interface for the voice band codec and an I2C/SPI

compatible interface for control. The full range music

path features an SNR of 86dB with an 18-bit 48kHz

input. The headphone amplifier delivers at least

26mWRMS to a 32Ω single-ended stereo load with

less than 1% distortion (THD+N) when AVDD =

3.3VDC. The mono speaker amplifier delivers up to

570mWRMS into an 8Ω load with less than 1%

distortion when AVDD = 3.3VDC.