A 22nm ±0.95V CMOS OTA-C front-end with 50/60 Hz notch for biomedical signal acquisition

This paper presents a 22 nm CMOS technology analog front-end (AFE) for biomedical applications. The circuit is designed for low power and small size implementations, especially for battery-powered implantable devices, and is capable of reading out biomedical signals in the range of 0.01 Hz to 300 Hz in frequency, while rejecting power-line frequency of 50/60Hz. It employs Operational Transconductance Amplifiers (OTAs) in an OTA-C structure to realize a notch filter. The OTA designed has a very low transconductance, which is programmable from 1.069 nA/V to 2.114 nA/V. The notch at power-line frequency (50/60 Hz) achieves an attenuation of 20 dB. The power consumption of the entire AFE was found to be 11.34 nW at ±0.95V supply.