Design of Bio-Medical Opamp

An operational amplifier for bio-medical application is proposed. The opamp includes rail-to-rail input stage, folded cascade stage with class AB biasing and a constant Gm stage. The opamp is made programmable to operate in two modes as low power mode and low noise mode. The opamp is realized in 130nm CMOS technology using H-Spice in Synopsis tool. The performed simulation shows a de open loop gain of 97.755dB, CMRR of 112.41dB under a 22k and 13.5pF load.