CMOS Implementation of Current Differencing Operational Amplifier and Its Notch Filter Application

Abstract

Active elements are fundamental circuits for a wide scope of scientific and industrial processes. Many researchers have examined active devices to implement filters, oscillators, rectifiers, and converters. This paper presents the current differencing operational amplifier (CDOA) as an active element, firstly implemented with CMOS transistors. The input part of this circuit is a current differencing unit and the conventional operational amplifier (Op-Amp) pursues it. A new realization of a notch filter consists of CDOA is suggested. Voltage-mode band-pass filter and current-mode notch filter are presented as a different filter applications. Simulation results using TSMC 0.18-mu m CMOS process model are used to verify the theoretical analyses. The sensitivity, noise, total harmonic distortion (THD) and the Monte Carlo analysis have been performed to demonstrate the effectiveness of the proposed active element and notch filter.