Switched Capacitor Biquad Filter Using CDTA


A switched capacitor biquad filter using current differencing transconductance amplifier (CDTA) is presented in this paper. The proposed circuit employs only one CDTA, two virtually grounded capacitors and one switched capacitor. It is a resistorless circuit, so it is beneficial to IC implementation in terms of space consideration. The proposed circuit is a second order single input multiple output (SIMO) current-mode filter. This filter can simultaneously realize all basic filter functions high pass, low pass and band pass responses without any component-matching conditions. All the active and passive sensitivities are low. The natural angular frequency (ω0) and quality factor (Q) of proposed filter can be electronically controlled. Owing to current mode operation it consumes less power. PSPICE simulation results are used to verify the theoretical analysis.

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Dehran, M. , Singh, I. , Singh, K. and Singh, R. (2013) Switched Capacitor Biquad Filter Using CDTA. Circuits and Systems, 4, 438-442. doi: 10.4236/cs.2013.46057.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] D. Biolek, “CDTA-Building Block for Current-Mode Analog Signal Processing,” Proceedings of European Conference on Circuit Theory and Design (ECCTD), Poland, 1-4 September 2003, pp. 397-400.
[2] D. Biolek and V. Biolkova, “Universal Biquad Using CDTA Elements for Cascade Filter Design,” Proceeding of 7th International Multiconference on Circuits, Systems Communications and Computers (CSCC), Athens,7-9 July 2003, pp. 8-12.
[3] A. T. Bekri and F. Anday, “Nth-Order Low-Pass Filter Employing Current Differencing Transconductance Amplifiers,” Proceeding of the 2005 European Conference on Circuit Theory and Design, Cork, 28 August-2 September 2005, pp. 193-196. http://dx.doi.org/10.1109/ECCTD.2005.1523026
[4] D. Biolek and V. Biolkova, “CDTA-C Current-Mode Universal 2nd Order Filter,” Proceeding of the 5th WSEAS International Conference on Applied Informatics and Communications, Malta, 15-17 September 2005, pp. 411-414.
[5] W. Tanjaroen, T. Dumawipata, S. Unhavanich, W. Tangsrirat and W. Surakampontorn, “Design of Current Differencing Transconductance Amplifier and Its Application to Current-Mode KHN Iquad Filter,” Proceeding of ECTICON, Ubon Ratchathani, 10-13 May 2006, pp. 497-500.
[6] D. Prasad, D. R. Bhaskar and A. K. Singh, “Universal Current-Mode Biquad Filter Using Dual Output Current Differencing Transconductance Amplifier,” International Journal of Electronics and Communications, Vol. 63, No. 6, 2008, pp. 497-501.
[7] A. Uygur and H. Kuntman, “Design of a Current Differencing Transconductance Amplifier (CDTA) and Its Application on Active Filters,” SIU’2005: IEEE 13th Signal Processing and Communication Applications Conference, Kayseri, 16-18 May 2005, pp. 340-343.
[8] N. A. Shah, M. Quadri and S. Z. Iqbal, “Current Mode Multifunction Filter Using Current Differencing Transconductance Amplifier,” Indian Journal of Pure & Applied Physics, Vol. 45, No. 9, 2007, pp. 767-769.
[9] D. Biolek, V. Biolkova and Z. Kolka, “Single-CDTA (Current Differencing Transconductance Amplifier) CurrentMode Biquad Revisited,” WSEAS Transactions on Electronics, Vol. 5, No. 6, 2008, pp. 250-257.
[10] D. Biolek, E. Hancioglu and A. U. Keskin, “High-PerforMance Current Differencing Transconductance Amplifier and Its Application in Precision Current-Mode Rectification,” International Journal of Electronics and Communications, Vol. 62, No. 2, 2008, pp. 92-96. http://dx.doi.org/10.1016/j.aeue.2007.03.003
[11] M. Bhusan and R. W. Newcomb, “Grounding of CapaciTors in Integrated Circuits,” Electronics Letters, Vol. 3, No. 4, 1967, pp. 148-149. http://dx.doi.org/10.1049/el:19670114
[12] K. Pal and R. Singh, “Inductor Less Current Conveyor All Pass Filter Using Grounded Capacitors,” Electronics Letters, Vol. 18, No. 1, 1982, p. 47. http://dx.doi.org/10.1049/el:19820033

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