Abstract :

A new electronically tunable current-mode third order filter is proposed in this paper. OP-AMP is used as an active building block. With current input the filter can realize band pass responses in current mode. The filter circuit realizes calculated transfer function. The other attractive features of the filter are a) Employment of minimum active and passive elements b) Responses are electronically tunable c) Low active and passive sensitivities d) Suitable for high frequency operation e) Ideal for integrated circuit implementation.

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Keywords :

Band Pass, Center Frequency, Circuit Merit Factor, Current Mode Filter, Electronically Tunable

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References :

1. Vasudev K. Aatre, “Network Theory & Filter Design”, 2nd Edition, New Age International (P)Ltd., 1980.
2. Ramakant Gayakward,”Op-Amps and Linear Integrated Circuits” 4th Edition by Pearson Education, Inc.,2000.
3. D.R. Bhaskar, U.R.Sharma, S.M.I.Rizvi”Current-mode universal biquadratic filter” Microelectronic Journal 1999 Vol-88, PP-837-839.
4. G.N.Shinde,P.R.Mirkute,”Three in one active-R filter”, Lab Experiments,Vol.3 No.1 pp.35-40,2003.
5. A.B.Kadam, A.M.Mahajan,” Effect of positive feedback on response of active-R filter”J. Instrumentation Society of India, 25 (1 and 2), pp.45-48, 1995.
6. S.Srinivasan,”Synthesis of transfer functions using operational amplifier pole”,Int.J. Electronics, Vol.40 (1), 5-13, 1976.
7. Takao Tsukutani, Masami Higashimura, Yasuaki Sumi and Yutaka Fukui “Electronically tunable current mode active-only biquadratic filter” Int. J Electronics, 2000, Vol. 87 No. 3, 307-314
8. Shinde G. N., Achole P. D. “Multiple feedback third order active-R filter with varying tapping ratio” Indian J Physics 80 (2), 187-190, 2006
9. Masami Higashimura “Active-R realization of current-mode high pass filter” INT J Electronics, 1992, volume number 6, 1279-1283, 1992.
10. Tskutani T, Ishida M. and Fuksui Y., “Cancellation technique of parasitic poles for active-R high pass filter.” Transaction of the Institute of Electronics and Communication Engineering of Japan, 1991, Pt. E 75, 1083-1085.
11. Mitra A. K. and Aatre V. K. “Low sensitivity high frequency active R filters”, I.E.E.E. Transactions on Circuits and Systems, 1976, 23, 670-676.
12. M.Ghousi,”Analog active filters”, I.E.E.E. Transactions on Circuits and Systems,Vol.31, pp.13-31, 1984.
13. G.N. Shinde and D.D.Mulajkar,” Frequency response of electronically tunable current-mode third order high pass filter for central frequency fo = 10 k with variable Circuit merit factor Q”, Scholars Research Library, Journal of Archives of Applied Science Research, 2-3,248-252, 2010.