A Gain and Bandwidth Individually Tunable ExG Analog Frontend with 516nV(rms) Noise for Flexible Biomedical Sensors

This paper presents a low-power, low-noise, gain and bandwidth individually tunable analog front-end (AFE) for ExG signals. The proposed three-stage AFE with a bandwidth programmable amplifier enables individually tuning the bandpass cutoff frequencies in the range of 0.4 to 1.9kHz as well as the gain from 40 to 63dB. Designed in a 0.35 mu m CMOS process with an area of 0.3mm(2), the AFE achieves over 120dB CMRR with input referred noise of 516nV(rms) and a noise efficiency factor of 2.57. The chip consumes 2.5 mu A at 1.8V supply.