HIGH GAIN TWO-STAGE CLASS-AB OPERATIONAL TRANSCONDUCTANCE AMPLIFIER

Abstract

A new two-stage class-AB operational transconductance amplifier that is suitable for analog-to-digital converters (ADC) and switched capacitor (SC) filters is presented. The proposed design is based on adaptive biasing at the input stage, cascoding and class-AB output stage techniques. The OTA have been designed in 0.18 µm CMOS technology with simulation results showing gain and gain bandwidth improvements of 201% and 12% respectively when compared to a conventional Class-AB OTA. The circuit is operated at 1.8V supply voltage. 

Keywords: Integrated circuits, analog CMOS circuits, amplifiers, two-stage, class-AB, adaptive biasing, high gain, gain bandwidth, operational transconductance amplifier (OTA)