SITO-Type High-Input Impedance Voltage-Mode Multifunction Filter Using Single Active Element

Abstract

This paper deals with a voltage-mode multifunction filter using only single newly defined active element labeled as voltage differencing gain amplifier (VDGA), and four passive elements. The presented circuit has one input and three outputs, and can realize highpass, bandpass and lowpass biquadratic filtering functions simultaneously without altering the circuit topology. Apart from these characteristics, the circuit also exhibits the desirable features such as high impedance for the input voltage signal and orthogonal adjustment of the natural angular frequency and the quality factor, and low sensitivity performance. The filter exhibits high-input impedance terminal. The operation of the proposed filter is evaluated through simulation results based on $0.25-\boldsymbol{\mu}\mathbf{m}$ CMOS technology from TSMC.