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.