Realisation of DVCC based operational amplifier and its bandpass filter application

Abstract

In this paper a DVCC based operational amplifier has been proposed. A pole has been introduced in transfer characteristic of DVCC by an integrated capacitor. The op amp is composed of an on chip DVCC, one integrated NMOS resistor, a capacitor and a CMOS voltage follower. The bandwidth of DVCC op amp can be adjusted by voltage tuning of the resistor. Conventional voltage mode operational amplifiers suffer from introduction of second pole at high frequencies, thus rendering the circuits suitable for low frequency applications only. The proposed DVCC op amp has large signal bandwidth and can operate for wide range of frequencies. A bandpass filter has been tested using the reported op amp in PSPICE and theoretical analysis has been presented.