Signal Flow Graph Synthetical Implement the Current-Mode Multifunction Filter Based on CDTA

Abstract

In this paper, a signal flow graph structure of current-mode multifunction filter using current differencing transconductance amplifier (CDTA) is presented. The proposed configuration is comprised of two grounded capacitors and four CDTAs. They exhibit low-input and high-output impedances, which is very convenient for integrated circuit implementation. The presented filter configuration can realize all the standard filter functions simultaneously, lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), without any component matching conditions. The natural frequency () and the bandwidth () of the proposed filter can be electronically tuned by varying the bias current of the CDTA. PSPICE simulation results are included to confirm the theory.