The AD1937 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, using the Analog Devices, Inc., patented multibit sigma-delta (Σ-Δ) architecture. An I2C® port is included, allowing a microcontroller to adjust volume and many other parameters. The AD1937 operates from 3.3 V digital and analog supplies. The AD1937 is available in a 64-lead (differential output) LQFP.The AD1937 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 (frame) clock or from an external crystal, the AD1937 elimi-nates 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 architecture to further minimize EMI. By using 3.3 V supplies, power consumption is minimized and further reduces emissions.