Design of High Gain Operational Transconductance Amplifiers in 180 nm CMOS technology

This paper presents two architectures of two-stage Operational Transconductance Amplifiers (OTAs). To achieve high gain, folded cascode topology is used. The first architecture uses an external bias which can be controlled independent of the OTA gain and bandwidth, while the second architecture uses a self-bias which reduces the power dissipation at the expense of restricted control over gain and bandwidth tuning. The two topologies are implemented using UMC 180 nm CMOS 1P9M technology. Both the architectures provide higher gain and consume less power in comparison to the previously published results.

I. Introduction

Operational Transconductance Amplifier, commonly known as OTA, is an integral part of many analog and mixed signal systems. OTAs are the basic building blocks in many integrated circuits that offer wide bandwidth. These find wide usage in a variety of radio frequency, intermediate frequency and high-performance video applications. OTAs are also used in automatic gain control amplifiers and drivers, integrators for fast pulses, active filters and in current-controlled oscillators.