Wide dynamic range 653 nW CMOS neurophysiological signal recording micro-brain-implant with opamp sharing technique

In this paper we present a low power, low noise CMOS micro-brain-implant which records both brain's electrical and chemical activities. We minimized the power consumption and silicon area by exploiting opamp sharing technique. This wide dynamic range (85 dB) micro device consists of a single nano-watt power amplifier for both micromolar neurotransmitter sensing and micro voltage action-potential recording. It digitizes the signal to ten bits using a first order delta-sigma analog-to-digital-convertor, all fabricated in TSMC CMOS-0.18 technology. This microsystem is validated applying neurophysiological signals.