描述 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 32? 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 8? load with less than 1% distortion when AVDD = 3.3VDC.

The LM4931 employs advanced techniques to reduce power consumption, to reduce controller overhead, and to eliminate click and pop. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. It is therefore ideally suited for mobile phone and other low voltage applications where minimal power consumption, PCB area, and cost are primary requirements.

特性 Features

? 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 8? 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
Key Specifications
? PLS OUT at AVDD = 5V, 8?
? 1% THD+N, 1.1W (Typ)

? PLS OUT at AVDD = 3.3V, 8?
? 1% THD+N, 570mW (Typ)

? PH/P OUT at AVDD = 5V & AVDD = 3.3V, 32?
? 1% THD+N, 26mW (Typ)

? Supply Voltage Range
? DVDD, 2.7V to 4.0V
? AVDD, 2.7V to 5.0V

? Shutdown Current, 1.1μA
? PSRR at 217Hz, AVDD = 3V, 62dB (Typ)
? SNR (Voice Codec), 75dB (Typ)
? SNR (Audio DAC), 86dB (Typ)