The NAU85L40B is a low-power, high-quality, 4-channel ADC designed for microphone array applications. The NAU85L40B integrates programmable gain preamplifiers for quad differential microphones, significantly reducing external component requirements.  A fractional FLL is available to accurately generate any audio sample rate using any commonly available system clock source, ranging from 8 kHz through 33 MHz. Audio data can be directed to two I2S data out lines or onto a single time-division multiplexed (TDM) PCM data output.

• Features
  

  -	Supports sample rates from 8 kHz to 96 kHz at 24-bit solution
  -	Two separate microphone bias supplies for low-noise microphone biasing
  -	Standard audio data bus interfaces: I2S, Left or Right justified, TDM (4 channel), Two’s complement, MSB first
  -	Integrated programmable gain microphone amplifier
  -	I²C Serial control interface with read/write capability

• Specifications
  

  -	On-chip FLL
  -	101 dB SNR (A-weighted) @ 0 dB gain
  -	92 dB THD+N @ 0 dB gain, 0.8 Vrms in
  -	-124 dB Channel Crosstalk @ 0 dB gain
  -	Package: Pb-free 28L-QFN
  -	Operating Temperature: -40 to 85°C

• System Block Diagram