Super class AB-AB bulk-driven folded cascode OTA

Abstract

A super class AB-AB bulk-driven folded cascode operational transconductance amplifier (OTA) with improved slew rate and unity-gain bandwidth is presented. The proposed bulk-driven amplifier utilizes the adaptively biased circuits, the bulk-driven flipped voltage follower and quasi-floating gate circuit, to implement the class-AB input stage and class-AB output stage respectively, which provides enhanced unity-gain bandwidth and dynamic current boosting. The proposed bulk-driven OTA is simulated on the 0.18 μm SMIC process with 1 V low voltage supply. The simulation results show that the proposed class AB-AB bulk-driven OTA achieves the increased factor of 6.5 and 4.7 in unity-gain bandwidth and slew rate compared with that of conventional class-A counterpart with only 50% extra power consumption.