Double-differential recording and AGC using amplifier ASIC

Abstract

An automatic gain control circuit (AGC) and a circuit for double-differential (DD) recording are implemented using an integrated variable gain circuit. The integrated circuit enables gain trimming by variation of the chip clock timing. A microcontroller is used to provide the clocks. AGC and DD setups with a simple 2-chip and 3-chip system respectively are realized. Measured results confirm a gain tuning range of 22.7 dB and interference suppression of 41.4 dB in the balanced DD arrangement, and power consumption of 318 µW.