Current feedback-op-amp-based synthetic impedances

Abstract

Besides the op-amp based and operational transconductance amplifier-based gyrators and impedance simulators, the current-feedback operational amplifier (CFOA)-based circuits of these elements are attractive because of the commercial availability of the CFOA AD844 as an off-the-shelf IC. In this chapter, we consider the prominent circuits for realizing gyrators, lossless grounded inductance (GI)/ lossless floating inductance (FI) circuits as well as the more generalized generalized positive impedance converter/inverter and generalized negative impedance converter/inverter elements using CFOAs. It is found that a class of economic impedance simulation circuits based on the use of single CFOA offer the attractive features of single resistance tunability which is not available in the well-known single op-amp-based simulators of the same kind of impedances. A number of inductors and resonators using CFOA poles and a class of GI/FI simulators using a modified CFOA have also been included.