Three Input Single Output Voltage-Mode Multifunction Filter with Independent Control of Pole Frequency and Quality Factor

Witthaya Mekhum,Winai Jaikla

doi:10.15598/aeee.v11i6.848

Abstract

This paper presents a voltage-mode biquadratic filter performing completely standard functions: low-pass, high-pass, band-pass, band-reject and all-pass functions, based on single voltage differencing transconductance amplifier (VDTA). The proposed filter has three input voltage and a single output voltage. The features of the circuit are that; the quality factor and natural frequency can be tuned independently; the circuit description is very simple, consisting of merely one VDTA, one resistor and two capacitors; the pole frequency can be electronically adjusted. Additionally, each function response can be selected by suitably selecting input signals with digital method; the double input voltage is not required. Using only single active element, the proposed circuit is very suitable to further develop into an integrated circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation.

Highlights

Filters are important blocks in many integrated circuit applications such as radio frequency applications, data conversion in A/D and D/A systems and many others [1], [2], [3]
Some filter circuits which use active building block can avoid the use of the external resistors
The aim of this paper is to propose a multiple-input single-output biquadratic filter (MISO) voltagemode filter, emphasizing on the use of single voltage differencing transconductance amplifier (VDTA) as the active element

Summary

Introduction

Filters are important blocks in many integrated circuit applications such as radio frequency applications, data conversion in A/D and D/A systems and many others [1], [2], [3]. Obtains a minimum number of components required to achieve a second-order transfer function; low pass (LP), high pass (HP), band pass (BP), band stop (BS) and all pass (AP) functions are obtained without any change in the filter topology

VDTA Overview

Principle of Operation

Proposed MISO Voltage-Mode Filter

Analysis of Non-Ideal Case

Simulation Results

Conclusion