A 1V low-power low-noise biopotential amplifier based on flipped voltage follower

Abstract

This paper presents a low-voltage low-power low-noise amplifier suitable for neural recording applications. Based on the flipped voltage follower (FVF) topology, the amplifier is able to operate under a 1 V supply by alleviating the tradeoff between the noise and the voltage headroom. A gm-cell was built using FVF, its effective transconductance is not a function of the bias current, so the noise contribution of the output transistors can be decreased without increasing the bias current. This amplifier is designed and simulated in a 130 nm CMOS process. The amplifier consumes 2.2 μW from 1 V supply voltage. The input referred noise is 3.7 μVrms. The amplifier has a BW from 25 Hz to 9.9 kHz.