A Low-Noise Low-Power Chopper Amplifier With 130dB CMRR and High SNR

This paper presents a low-power and low-noise chopper amplifier for biopotential signals. A two-stage structure is presented to achieve a high CMRR and SNR. These stages contain a folded cascode topology to obtain a low input noise and large input impedance; and a stage of two stacked cross-coupled folded cascode for CMRR and SNR intents. The structure consumes 1.27 µW from a 0.6 V power supply. The CMRR, SNR, Gain, and input-referred noise RMS respectively are 133 dB, 121.4 dB, 38 dB and 930nV/Hz in the Bandwidth of 0.01 kHz to 1 kHz. The NEF and PEF are 1.8 and 1.9 and input impedance is 2.5 GΩ with chopping frequency of 2kHz.