Generalization of a Theorem for Replacing CCIIs by CFOAs in Current-Mode Circuits

Abstract

A current feedback op-amp (CFOA) has the advantage that feedback structures in current-mode circuits are more easily devised because the voltage buffer at the output of the CFOA does not load the output of the integral positive, second-generation current conveyor (CCIIp) that constitutes part of the CFOA. In this paper, the changes on the current mode transfer function of a linear circuit composed of a subnetwork N connected to a CCIIp are determined when the CCIIp is replaced by a CFOA and a feedback component is connected from the output of the CFOA to an independent node of N. Two applications of the results are provided. A new theorem is then presented which generalizes the results. This theorem should be useful for the comparison, synthesis, and improvement of linear current-mode signal processing circuits.