A 60μW 60nV/radicHz readout front-end for portable biopotential acquisition systems

A biopotential readout front-end can be configured to extract EEG, ECG, and EMG signals and draws 20μA from 3V. AC coupling of chopped amplifiers results in an input-referred noise of 60nV/radicHz and CMRR of 120dB at 1kHz. The immunity of the CMRR to electrode offset voltages is improved with an active input stage and 110dB CMRR is achieved at 100Hz with 50mV electrode offset