A Low noise Low power Chopper Stabilized Biopotential Amplifier for Biomedical Applications

Abstract

This paper presents a chopper-stabilized biopotential amplifier designed to amplify ECG and EEG signals. Such amplifier plays an important role in the acquisition of bio-signals in analog front-end of the signal monitoring system. The proposed amplifier is designed with considering primary design goals like power, noise, gain, CMRR, area and offset. To reduce the flicker noise and offset, the chopper stabilization technique is used with OTA. As the parameters like offset, input impedance and 3-dB bandwidth are crucial for monitoring the bio-signals, the chopping frequency for the chopper modulator is carefully selected. Also, due to only one OTA which is the main power consuming block, the overall power dissipation is low. The designed architecture consumes a total power of 8 µW with the gain of 40dB and CMRR of 84 dB. It generates 31nV/√Hz with a THD of 13%. The simulations are carried out in Cadence Virtuoso using 180 nm model parameters.