4 ADC/8 DAC with PLL, 192 H, 24-Bit CODEC

The AD1938 is a high performance, single-chip codec that provides four analog-to-digital converters (ADCs) with input and eight digital-to-analog converters (DACs) with single-ended output using the Analog Devices, Inc., patented multibit sigma-delta (Σ-Δ) architecture. An SPI port is included, allowing a microcontroller to adjust volume and many other parameters.

The AD1938 operates from 3.3 V digital and analog supplies. The AD1938 is available in a 48-lead (single-ended output) LQFP package. Other members of this family include a differential DAC output and I2C® control port version.

The AD1938 is designed for low EMI. This consideration is apparent in both the system and circuit design architectures. By using the on-board PLL to derive the master clock from the LR clock or from an external crystal, the AD1938 eliminates the need for a separate high frequency master clock and can also be used with a suppressed bit clock. The DACs and ADCs are designed using the latest Analog Devices continuous time architectures to further minimize EMI. By using 3.3 V supplies, power consumption is minimized, further reducing emissions.

APPLICATIONS

* Automotive audio systems

* Home Theater Systems

* Set-top boxes

* Digital audio effects processors

* PLL generated or direct master clock

* Low EMI design

* 108 dB DAC/107 dB ADC dynamic range and SNR

* −94 dB THD + N

* Log volume control with autoramp function