The AD1939 is a high performance, single-chip codec that provides four analog-to-digital converters (ADCs) with differential input, and eight digital-to-analog converters (DACs) with differential output. An SPI port is included, allowing a microcontroller to adjust volume and many other parameters. The AD1939 operates from 3.3 V digital and analog supplies. The AD1939 is available in a 64-lead (differential output) LQFP package. The AD1939 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 AD1939 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.
PLL generated or direct master clock
Low EMI design
112 dB DAC/107 dB ADC dynamic range and SNR
-94 dB THD + N
Single 3.3 V supply
Tolerance for 5 V logic inputs
Supports 24-bits and 8 kHz to 192 kHz sample rates
Differential ADC input
Differential DAC output
Log volume control with autoramp function
SPI controllable for flexibility
Applications include Automotive audio systems, Home Theater Systems, Set-top boxes, Digital audio effects processors