Design and Evaluation of Fully Differential OTAs Based on CMOS Inverters

Abstract

There are strong demmands for low-voltage operating OPA/OTA in deep sub-micron CMOS processes. We have proposed a CMOS inverter based two-stage OTA configuration named F/F+F/B OTA, which can operate 1V to 1.8V of supply voltage, for an 0.18μm CMOS process. In this report, three series of fabrication results for the proposed F/F+F/B OTA configurations are presented with their design details. We have improved common-mode rejection ratio and voltage gain over the prototype chip. The revised chip demonstrated 79dB of differential voltage gain, unity frequency of 3.8MHz, with 124dB of CMRR, from 1.0V of power supply with 200μA of current consumption.