implementations of electronically tunable first and second order allpass filter
(AP) structures using a Multiplication Mode Current Conveyor (MMCC) building
block are presented. The control voltage (V) of the MMCC tunes the desired
phase (θ) while the time constant (τ) is adjustable by a Differential
Voltage Current Conveyor Transconductance Amplifier (DVCCTA)-based synthetic
lossless grounded inductor (L). The circuits are analyzed taking into account
the device imperfections which show low active
sensitivity features of the designs. The effects of port transfer error
(ε) and that of the parasitic
capacitances of the active devices had been meticulously examined which
indicated that certain deviations in nominal design equations occur; these however,
could be minimized with appropriate choice of the circuit passive components.
Readily available AD-844 type Current Feedback Amplifier (CFA) elements are
utilized for the topology implementation. Satisfactory test results on
electronic θ-tunability, upto about
300 KHz, had been verified by PSPICE simulation and with hardware
 Ponsonby, J.E. (1966) Active Allpass Filter Using a Differential Operational Amplifier. Electronics Letters, 2, 134-135.http://dx.doi.org/10.1049/el:19660107
 Genin, R. (1968) Realisation of an Allpass Transfer Function Using Operational Amplifier. Proceedings of the IEEE, 56, 1746-1747. http://dx.doi.org/10.1109/PROC.1968.6731
 Nandi, R. (1977) New Allpass Phase Shifters. International Journal of Electronics, 42, 97-99. http://dx.doi.org/10.1080/00207217708900617
 Soliman, A.M. (1973) Inductorless Realization of Allpass Transfer Function Using the Current Conveyor. IEEE Transactions on Circuits and Systems I, 20, 80-81.
 Nandi, R. (1992) Novel Current Mode Allpass Phase Shifters Using a Current Conveyor. IEEE Transactions on Instrumentation and Measurement, 41, 553-555. http://dx.doi.org/10.1109/19.155925
 Higashimura, M. and Fukui, Y. (1990) Realization of Current Mode Allpass Networks Using a Current Conveyor. IEEE Transactions on Circuits and Systems I, 37, 6660-6661. http://dx.doi.org/10.1109/31.55015
 Pandey, N., Pandey, R. and Paul, S.K. (2012) A First Order Allpass Filter and its Application in a Quadrature Oscillator. Journal of the Electron Devices Society, 12, 772-777.
 Mohan, J., Maheshwari, S. and Chauhan, D.S. (2010) Voltage Mode Cascadable Allpass Sections using Single Active Element and Grounded Passive Components. Journal of Circuits and Systems—Scientific Research Publishing, 1, 5-11.
 Toker, A. and Ozoguz, S. (2004) Novel Allpass Filter Using Differential Difference Amplifier. AEU—International Journal of Electronics and Communications, 58, 153-155. http://dx.doi.org/10.1078/1434-8411-54100221
 Biolek, D. and Biolkova, V. (2009) Allpass Filter Employing One Grounded Capacitor and One active Element. Electronics Letters, 45, 807-808. http://dx.doi.org/10.1049/el.2009.0575
 Psychaslinos, C. and Pal, K. (2010) A Novel Allpass Current Mode Filter Realized Using a Minimum Number of Single-Output OTAs. Journal of Frequenz, 64,123-129.
 Biolek, D. and Biolkova, V. (2010) First Order Voltage Mode Allpass Filter Employing One Active Element and One Grounded Capacitor. Analog Integrated Circuits and Signal Processing, 65, 123-129.
 Ibrahim, A., Minaei, S. and Yuce, E. (2012) Allpass Sections with Rich Cascadability and IC Realization Suitability. International Journal of Circuit Theory Applications, 40, 461-472.
 Wangenheim, L.V. (2012) Phase Margin Determination in a Closed Loop Configuration. Journal of Circuit System and Signal Processing, 31, 1917-1926. http://dx.doi.org/10.1007/s00034-012-9437-7
 Herencsar, N., Minaei, S., Koton, S., Yuce, E. and Vrba, K. (2013) New Resistorless and Electronically Tunable realization of Dual-Output VM Allpass Filter Using VDIBA. Journal of Analog Integrated Circuits and Signal Processing, 74, 141-154. http://dx.doi.org/10.1007/s10470-012-9936-2
 Nandi, R., Kar, M. and Das, S. (2009) Electronically Tunable Dual-Input Integrator Employing a Single CDBA and a Multiplier. Journal of Active and Passive Electronic Components, 2009, 1-5. http://dx.doi.org/10.1155/2009/835789
 Li, Y.A. (2014) Electronically Tunable Current Mode Biquadratic Filter and Four-Phase Quadrature Oscillator. Microelectronics Journal, 45, 330-335.
 Hwang, Y.S., Liu, W.H., Tu, S.H. and Chen, J.J. (2009) New Building Block: Multiplication Mode Current Conveyor. Circuits, Devices and Systems—The IET, 3, 41-48
 Intersil Datasheet (1998) File #2477.5 and (Apr.1999) File #2863.4.
 Analog Devices (1990) Linear Products Databook. Norwood.
 Tammam, A.A., Hayatleh, K., Ben-Esmael, M. and Terzopoulus, N. (2013) Critical Review of the Circuit Architecture of CFOA. International Journal of Electronics, 101, 441-451.
 Palumbo, G. and Pennisi, S. (2001) Current Fedback Amplifiers versus Voltage Operational Amplifiers. IEEE Transactions on Circuits and Systems I, 48, 617-623. http://dx.doi.org/10.1109/81.922465
 News Updates (2004) Internet Version: Global Signal Processing Times.
 Nandi, R., Kar, M. and Das, S. (2011) Synthetic Inductor Based Resonators Using DVCCTA. Proceedings of International Conference EUROCON, Portugal, 584-586. http://dx.doi.org/10.1109/EUROCON.2011.5929212
 Macromodel of AD-844 AN in PSPICE Library (1992) Microsim Corpn. Irvine.
 Venkateswaran, P., Nandi, R. and Das, S. (2012) New Integrators and Differentiators Using a MMCC. Circuits and Systems, 3, 288-294. http://dx.doi.org/10.4236/cs.2012.33040