A 7.5GΩ-Input-Impedance 109dB-Total-CMRR and 80VPP-CMI-Tolerance Instrumentation Amplifier for Dry-Contact Two-Electrode ECG Monitoring

This paper presents an instrumentation amplifier (IA) customized for dry-contact two-electrode ECG measurement. By utilizing the adaptive current generator, the residual common-mode-interference (CMI) voltage fluctuation prior to the IA is minimized and this facilitates up to 80V
PP
environmental CMI tolerance. In addition, a chopping-free capacitively-coupled IA (CCIA) with CM replication scheme offers rail-to-rail DC electrode offset (DEO) rejection and high input impedance of 7.5GΩ. This IA also mitigates the CMRR limitation due to the capacitors mismatch, leading to a total CMRR (T-CMRR) of 109dB.