GENERAL DESCRIPTION

The AD74322 is a front-end processor for general purpose audio and voice applications. It features two multi-bit Σ∆ A/D conversion channels and two multi-bit Σ∆ D/A conversion channels. Each ADC channel provides >85 dB signal-to-noise ratio while each DAC channel provides >90 dB, both over an audio signal bandwidth.

FEATURES

2.5V Stereo Audio Codec with 3.3 V Tolerant Digital Interface

Supports 96 kHz Sample Rates

Supports 16/18 /20/24-Bit Word Lengths

Multibit Sigma Delta Modulators with

“Perfect Differential Linearity Restoration” for Reduced Idle Tones and Noise Floor

Data Directed Scrambling DACs - Least Sensitive to Jitter

Performance (20 Hz to 20 kHz)

90 dB ADC and DAC SNR

Digitally Programmable Input/Output Gain

On-chip Volume Controls Per Output Channel

Hardware and Software Controllable Clickless Mute

Supports 256xFs, 512xFs and 768xFs Master Mode Clocks

Master Clock Pre-Scaler for use with DSP master clocks

Flexible Serial Data Port with Right-Justified, Left

Justified, I2S-Compatible and DSP Serial Port Modes

Supports Packed Data Mode (“TDM”) for cascading devices.

On-Chip Reference

16, 20 and 24-Lead SOIC, SSOP and TSSOP Package options.

APPLICATIONS

Digital Video Camcorders (DVC)

Portable Audio Devices (Walkman etc)

Audio Processing

Voice Processing

Conference Phones

General Purpose Analog I/O