Digitally Controlled Analog Microphone Preamplifier Using PGA2505
The project is based on PGA2505 which is a digitally controlled, analog microphone preamplifier designed for use as a front end for high performance audio analog to digital converters (ADC). The PGA features includes 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. PGA2504 features a gain range of 9dB through 60dB (3dB/Step) , along with unity gain setting.