A Voltage-Mode First Order Allpass Filter Based on VDTA

Suwat Maneewan,Phamorn Silapan,Nawee Udorn,Danupat Duangmalai,Winai Jaikla

doi:10.15598/aeee.v12i1.846

Suwat Maneewan, Phamorn Silapan + Show 3 more

Open Access

https://doi.org/10.15598/aeee.v12i1.846

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Journal: Advances in Electrical and Electronic Engineering	Publication Date: Mar 27, 2014
Citations: 25	License type: cc-by

Abstract

This article presents a new voltage-mode first order allpass filter (APF) employing voltage differencing transconductance amplifier (VDTA). The advantages of the circuit are that: the circuit description is very compact, consists of merely a VDTA and a capacitor: the phase shift can be electronically adjusted by current bias: it provides the lower THD of the output signal. Without any component matching conditions, the proposed circuit is very appropriate to further develop into an integrated circuit. Moreover, the proposed APF can provide the output current with high output impedance without modification of the circuit topology. The PSpice simulation results are depicted. The given results agree well with the theoretical anticipation. The maximum power consumption is 400µW at ±1.25V power supplies.

Highlights

A phase shifter or first order allpass filter (APF) is widely employed in analog signal processing system such as, oscillators, high-Q band-pass filters and phase shifters [1], [2], [3], [4], [5], [6]
The aim of this paper is to propose a voltage-mode first order allpass filter, emphasizing on the use of the voltage differencing transconductance amplifier (VDTA)
For non-ideal the VDTA can be respectively characterized with the following equations: Iz αpgm1 αN gm1

Summary

Introduction

A phase shifter or first order allpass filter (APF) is widely employed in analog signal processing system such as, oscillators, high-Q band-pass filters and phase shifters [1], [2], [3], [4], [5], [6]. The literature surveys display that the first-order all-pass filter circuit using different high-performance active building blocks such as, current conveyors (CCIIs) [7], [8], [9], [10], In 2011, the voltage differencing transconductance amplifier is presented [27]. It consists of 2 ports input voltage, 2 port output current and 2 external current bias. The aim of this paper is to propose a voltage-mode first order allpass filter, emphasizing on the use of the VDTA. The performances of proposed circuit are illustrated by PSpice simulations, they show good agreement as mentioned

Objectives

Results

Conclusion