Realization of a New Current Mode Second-Order Biquad Using Two Current Follower Transconductance Amplifiers (CFTAs)

Nisha Walde^*, Syed Naseem Ahmad

Department of Electronics & Comm. Engineering, Jamia Millia Islamia, New Delhi, India.

DOI: 10.4236/cs.2015.65012                

Abstract

A new circuit for realization of universal current-mode filter using current Follower Transconductance Amplifiers (CFTAs) is presented. The proposed circuit realizes current-mode low pass, high pass and band pass filter functions simultaneously with a single current source at the input. The band reject and all pass filters can also be obtained from the proposed circuit without any extra hardware. The proposed circuit employs three passive grounded elements and two CFTAs. Linear electronic control of natural frequency ω0 is available in the proposed circuit. The quality factor can be independently adjusted through grounded resistor. The proposed circuit employs two grounded capacitors and a grounded resistor along with two CFTAs. The grounded resistor can be replaced by an OTA based circuit for linear electronic control of quality factor Q0. The circuit exhibits low active and passive sensitivities for ω0 and Q0. Simulation results are obtained using PSPICE software which is in conformity with the theoretical findings.

Keywords

Current Follower Transconductance Amplifier (CFTA), Current-Mode Circuit, Biquad Filter, Voltage-Mode Circuit, Current Conveyor (CC)

Conflicts of Interest

The authors declare no conflicts of interest.

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