Low-Voltage Wide Linear Range Tunable Operational Transconductance Amplifier

Abstract

The design of tunable operational transconductance amplifier (OTA) with wide linear range has become increasingly challenging with the scaling in the power supply voltage. Tunability of OTA provides flexibility to change the range of filters as well as gain in automatic gain controllers. In recent years the use of voltage as a control parameter for tuning has become more difficult with the reduced supply voltage environment, which has result in lower noise margins and narrower linear range. In this dissertation, bias current approach is used along with floating-gate MOSFET to develop the low-voltage tunable OTAs namely, floating-gate MOSFET tunable grounded resistor based OTA and FGMOS based wide linear range (FGWLR) OTA. The proposed circuits are simulated using TSMC 0.18μm CMOS technology process parameters and their simulation results are presented. The applications of these circuits such as grounded resistor, low-pass filter and high-pass filter are developed and the simulation results of these circuits are also discussed. The layout of the proposed FGWLR OTA is designed using Cadence® Virtuoso XL Design Environment tool.