A Single Resistor Tunable Grounded Capacitor Dual-Input Differentiator


A new current feedback amplifier (CFA) based dual-input differentiator (DID) design with grounded capacitor is presented; its time constant (τo) is independently tunable by a single resistor. The proposed circuit yields a true DID function with ideal CFA devices. Analysis with nonideal devices having parasitic capacitance (Cp) shows extremely low but finite phase error (θe); suitable design θe could be minimized significantly. The design is practically active-insensitive relative to port mismatch errors (ε) of the active element. An allpass phase shifter circuit implementation is derived with slight modification of the differentiator. Satisfactory experimental results had been verified on typical wave processing and phase-selective filter design applications.

Share and Cite:

Mathur, K. , Venkateswaran, P. and Nandi, R. (2015) A Single Resistor Tunable Grounded Capacitor Dual-Input Differentiator. Circuits and Systems, 6, 49-54. doi: 10.4236/cs.2015.63005.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Pratt, T. and Bostian, C.W. (2006) Satellite Communications. John Wiley & Sons, Hoboken.
[2] Horrocks, D.H. (1974) A Noninverting Differentiator Using a Single Operational Amplifier. International Journal of Electronics, 37, 433-434.
[3] Nandi, R. (1979) New Grounded Capacitor Ideal Differentiators. Proceedings of the IEEE, 67, 685-687.
[4] Bandyopadhyay, A.K. and Nandi, R. (1978) True Noninverting Integrators with Single Grounded Capacitor. Proceedings of the IEEE, 66, 596-597.
[5] Patranabis, D. and Ghosh, D.K. (1984) Integrators and Differentiators with Current Conveyors. IEEE Transactions on Circuits and Systems, 31, 567-569.
[6] Lee, J.L. and Liu, S.I. (2001) Integrator and Differentiator with Time Constant Multiplication Using Current Feedback Amplifier. Electronics Letters, 37, 331-333.
[7] Nagaria, R.K. (2008) On the New Design of CFA Based Voltage Controlled Integrator/Differentiator Suitable for Analog Signal Processing. WSEAS Transactions on Electronics, 6, 232-237.
[8] Nandi, R., Sanyal, S.K. and Bandyopadhyay, T.K. (2009) Single CFA Based Integrator, Differentiator, Filter and Sinusoid Oscillator. IEEE Transactions on Instrumentation and Measurement, 58, 2557-2564.
[9] Horng, J.W. and Huang, G.T. (2013) A Grounded Capacitor Differentiator Using Current Feedback Amplifer. Circuits and Systems, 4, 233-236.
[10] Tomazou, C. and Lidgey, J. (1994) Current Feedback Op-Amp: A Blessing in Disguise. IEEE Circuits & Devices Magazine, 10, 34-37.
[11] Palumbo, G. and Pennisi, S. (2001) Current Feedback Amplifiers versus Voltage Operational Amplifiers. IEEE Transactions on Circuits and Systems, 48, 617-623. http://dx.doi.org/10.1109/81.922465
[12] Gift, S.J.G. and Maundy, B. (2005) Improving the Bandwidth Gain-Independence and Accuracy of the Current Feedback Amplifier. IEEE Transactions on Circuits and Systems II, 52, 136-139.
[13] Tammam, A.A., Hayatleh, K., Ben-Esmael, M., Terzopoulos, N. and Sebu, C. (2014) Critical Review of the Circuit Architecture of the CFOA. International Journal of Electronics, 101, 441-451.
[14] Franco, S. (1989) Current Feedback Amplifiers Benefit High Speed Designs. EDN, 34, 161-172.
[15] Analog Devices (1990) Linear Products Databook. Norwood, MA.
[16] Microsim Corporation (1992) Macromodel of AD-844 AN in PSPICE Library. Irvine, CA.
[17] Cha, H.W., Ogawa, S. and Watanabe, K. (1998) Class-A CMOS Current Conveyors. IEICE Transactions on Fundamentals of Electronics, Communication & Computer Sciences, E81-A, 1164-1167.
[18] Terman, F.E. and Pettit, J.M. (1952) Electronic Measurements. McGraw-Hill Publishing, New York.

Copyright © 2021 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.