The PGA2505 is a digitally-controlled, analog microphone preamplifier designed for use as a front-end for high-performance audio analog-to-digital converters (ADCs). The PGA2505 features include low noise, wide dynamic range, and a differential signal path. An on-chip dc servo loop is employed to minimize dc offset, while a common-mode servo function may be used to enhance common-mode rejection.

The PGA2505 features a gain range of 9dB through 60dB (3dB/step), along with a unity gain setting. The wide gain range allows the PGA2505 to be used with a variety of microphones. Gain settings and internal functions are programmed using a 16-bit control word, which is loaded using a simple serial port interface. A serial data output pin provides support for daisy-chained connection of multiple PGA2505 devices. Four programmable digital outputs are provided for controlling the external switching of input pads, phantom power, and high-pass filters. The PGA2505 requires both +5V and -5V power supplies and is available in a small SSOP-24 package.