Realization of Electronic OTA Amplifiers with Linear and Tunable Transconductance and its Usages in Continuous - Filters

Subject Areas : Renewable energy

Ebrahim  Borzabadi ¹ (Associate Professor/ Najafabad Branch, Islamic Azad University)
Hamid Reza  Taghva ² (MSc/Research Center of Shahed Industrial, Sepah Air Force)
Homayoun  Mahdavi-Nasab ³ (Assistant Professor/Najafabad Branch, Islamic Azad University)

Received: 2009-09-16 Accepted : 2010-09-12 Published : 2012-02-01

Keywords: CMOS, OTA–active filters,

Abstract :

The aim of this paper is the introduction of a CMOS OTA basic block that its transconductance gain can be electronically and linearly tuned. This transconductance is proportional to the square root of the bias current. To achieve the maximum output voltage and create a wide range of linear  transconductance the CMOS OTA has been used.Then the variation of the transconductance and its effects on the performance of Continuous-time filters has been considered. The novelty of this paper is to show that how the transconductance of a first-Order filter is transformed to high pass and low pass filters and the transfer function of a second-order filter is transformed into high pass, low pass , band pass and band rejection filters. The performance of the proposed circuit is discussed and confirmed through MATLAB and PSPICE-simulation results.