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

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.

[1]  Peerawut Suwanjan,et al.  CFTA based MISO current-mode biquad filter , 2012 .

[2]  Kobchai Dejhan,et al.  CMOS-based near zero-offset multiple inputs max–min circuits and its applications , 2009 .

[3]  Kamil Vrba,et al.  Realization of Current-Mode KHN-Equivalent Biquad Using Current Follower Transconductance Amplifiers (CFTAs) , 2010, IEICE Trans. Fundam. Electron. Commun. Comput. Sci..

[4]  Kamil Vrba,et al.  Current-controlled CFTA-based current-mode SITO universal filter and quadrature oscillator , 2010, 2010 International Conference on Applied Electronics.

[5]  D. S. Chauhan,et al.  ZC-CFTA-based trans-impedance-mode universal biquad filter with electronic tuning , 2014, 2014 International Conference on Signal Processing and Integrated Networks (SPIN).

[6]  K. Smith,et al.  A second-generation current conveyor and its applications , 1970, IEEE Transactions on Circuit Theory.

[7]  D. Biolek,et al.  Active Elements for Analog Signal Processing: Classification, Review, and New Proposals , 2008 .

[8]  Worapong Tangsrirat.  SFG Synthesis of General High-Order All-Pass and All-Pole Current Transfer Functions Using CFTAs , 2014, TheScientificWorldJournal.

[9]  Kamil Vrba,et al.  A Novel Current-Mode SIMO Type Universal Filter Using CFTAs , 2009 .

[10]  Peerawut Suwanjan,et al.  Current-mode variable current gain first-order allpass filter employing CFTAs , 2013 .

[11]  W. Tangsrirat,et al.  Realization of current-mode KHN-equivalent biquad filter using ZC-CFTAs and grounded capacitors , 2011 .

[12]  Supawat Lawanwisut,et al.  A Current-mode Multifunction Biquadratic Filter Using CFTAs , 2012 .

[13]  Worapong Tangsrirat.  Novel current-mode and voltage-mode universal biquad filters using single CFTA , 2010 .

[14]  E. Sanchez-Sinencio,et al.  Active filter design using operational transconductance amplifiers: A tutorial , 1985, IEEE Circuits and Devices Magazine.

[15]  Abdhesh K. Singh,et al.  New Universal Current-mode Biquad Using Only Three ZC-CFTAs , 2012 .

[16]  Worapong Tangsrirat,et al.  Current-Mode KHN Biquad Filter Using Modified CFTAs and Grounded Capacitors , .

[17]  Christofer Toumazou,et al.  Analogue IC design : the current-mode approach , 1993 .

[18]  Worapong Tangsrirat.  Single-input three-output electronically tunable universal current-mode filter using current follower transconductance amplifiers , 2011 .