Realization of a reconfigurable Butterworth and Bessel filter using single operational transresistance amplifier and study of their performance

Abstract

In this article, a single operational transresistance amplifier (OTRA) based realization of second order low-pass (LP), high-pass (HP), band-pass (BP), band-reject (BR), and all-pass (AP) filter and their individual performance analysis: noise, temperature, and worst-case analysis have been presented. The proposed circuit can be reconfigured as Butterworth and Bessel filter by changing the values of passive components. The presented filters are suitable for MOS-C implementation, which facilitates tuning of cut-off/center frequency and quality factor electronically. The proposed circuits are analyzed theoretically, simulated and experimentally verified in laboratory. All the simulations are performed with CMOS model of OTRA (180 nm) in SPICE and experimentally verified with AD844AN IC. The experimental and simulation results are matching closely. The result obtained from post-layout simulation of the proposed Butterworth LP filter confirms the feasibility of the design. Finally working of the proposed all-pass filter is established by the design of a buffer and quadrature oscillator.