A 90 nm CMOS low noise readout front-end for portable biopotential signal acquisition

This article presents a programmable low-noise readout front-end suitable for biopotential signal acquisition. The chip includes a fully-differential chopper current-balancing instrumentation amplifier, a chopper spike filter, a small Gm-C low pass filter, and a programmable gain amplifier. The chopper current-balancing instrumentation amplifier achieved 104dB CMRR. The integrated input-referred noises within Electro-encephalogram (EEG) bandwidth and Electrocardiogram (ECG) bandwidth were 0.95 μV
_rms
and 1.51 μV
_rms
, respectively. Total power consumption was 26.56 μW under 1 V supply. The chip was implemented by TSMC 90nm CMOS 1P9M standard process.