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.