OTA-C Filters

  • P. V. Ananda MohanEmail author
Part of the Modeling and Simulation in Science, Engineering and Technology book series (MSSET)


In this chapter, the realization of filters using operational transconductance amplifiers (OTA) is considered. Building blocks such as OTA-C integrators, OTA-C differentiators, and first-order low-pass, high-pass, and all-pass OTA-C filters are described. Circuits with current/voltage input/output are considered. The use of dual current output OTAs is also studied. The realization of second-order voltage and current mode filters based on Tarmy–Ghausi active RC configuration as well as two integrator loop has been presented in detail. The design of ladder filters using simulated inductors and FDNRs is considered. The technique for high-order current-mode OTA-C filters based on coupled biquads is also described. In addition, the use of analytical synthesis technique to derive multiloop feedback type OTA-C filters is described. The effect of OTA nonidealities using pole-zero model as well as finite output resistance and capacitance of the OTAs on chosen filter configurations are presented. Structures for OTA-C oscillators are also presented. Noise analysis techniques and estimation of distortion are also described. SPICE simulation examples are given in order to illustrate certain ideas.


  1. [3.1]
    Silva-Martinez, J., Steyaert, M.S.J., Sansen, W.: A 10.7 MHz 68-dB SNR CMOS continuous-time filter with on-chip automatic tuning. IEEE J. Solid-State Circuits 27, 1843–1853 (1992)CrossRefGoogle Scholar
  2. [3.2]
    Tsividis, Y.P.: Integrated continuous-time filter design-an overview. IEEE J. Solid-State Circuits 29, 166–176 (1994)CrossRefGoogle Scholar
  3. [3.3]
    Geiger, R.L., Sanchez-Sinencio, E.: Active filter design using operational transconductance amplifiers: a tutorial. IEEE Circuits Devices Mag. 1, 20–32 (1985)CrossRefGoogle Scholar
  4. [3.4]
    Ananda Mohan, P.V.: Generation of OTA-C filter structures from active RC filter structures. IEEE Trans. Circuits Syst. 37, 656–660 (1990)CrossRefGoogle Scholar
  5. [3.5]
    Sun, Y., Fidler, J.K.: Structure generation of current-mode two-integrator loop dual output-OTA grounded capacitor filters. IEEE Trans. Circuits Syst. II 43, 659–663 (1996)CrossRefGoogle Scholar
  6. [3.6]
    Wu, J., El-Masry, E.I.: Design of current-mode ladder filters using coupled biquads. IEEE Trans. Circuits Syst. II 45, 1445–1454 (1998)CrossRefGoogle Scholar
  7. [3.7]
    Kamat, D.V., Ananda Mohan, P.V., Gopalakrishna Prabhu, K.: Novel first-order and second-order current mode filters using dual-output OTAs and grounded capacitors. IEEE TENCON (2008). doi: 10.1109/TENCON.2008.4766492
  8. [3.8]
    Al-Hashimi, B.M., Dudek, F., Moniri, M.: Current-mode group-delay equalization using pole-zero mirroring technique. IEE Proc. Circuits Devices Syst. 147, 257–263 (2000)CrossRefGoogle Scholar
  9. [3.9]
    Sanchez-Sinencio, E., Geiger, R.L., Nevarez-Lozano, H.: Generation of continuous-time two integrator loop OTA filter structures. IEEE Trans. Circuits Syst. CAS-35, 936–945 (1988)CrossRefGoogle Scholar
  10. [3.19]
    Tsukutani, T., Sumi, Y., Fukui, Y.: Electronically tunable current-mode OTA-C biquad using two-integrator loop structure. Frequenz 60, 53–56 (2006)Google Scholar
  11. [3.10]
    Chang, C.M.: New multifunction OTA-C biquads. IEEE Trans. Circuits Syst. II: Analog Digit. Signal Process. 46, 820–824 (1999)CrossRefGoogle Scholar
  12. [3.11]
    Horng, J.W.: Voltage-mode universal biquadratic filter using two OTAs. Act. Passive Electron. Compon. 27, 85–89 (2004)CrossRefGoogle Scholar
  13. [3.12]
    Horng, J.W.: Voltage-mode universal biquadratic filter with one input and five outputs using OTAs. Int. J. Electron. 89, 729–737 (2002)CrossRefGoogle Scholar
  14. [3.13]
    Chang, C.-M.: Analytical synthesis of the digitally programmable voltage-mode OTA-C universal biquad. IEEE Trans. Circuits Syst. II Expr. Briefs 53, 607–611 (2006)CrossRefGoogle Scholar
  15. [3.14]
    Sun, Y.: Second-order OTA-C filters derived from Nawrocki-Klein biquad. Electron. Lett. 34, 1449–1450 (1998)CrossRefGoogle Scholar
  16. [3.15]
    Nawrocki, R., Klein, U.: New OTA-capacitor realization of a universal biquad. Electron. Lett. 22, 50–51 (1986)CrossRefGoogle Scholar
  17. [3.16]
    Al-Hashimi, B.M., Dudek, F., Moniri, M., Living, J.: Integrated universal biquad based on triple-output OTAs and using digitally programmable zeros. IEE Proc. Circuits Devices Syst. 145, 192–196 (1998)CrossRefGoogle Scholar
  18. [3.17]
    Abuelma’atti, M.T., Bentrcia, A.: New universal current-mode multiple-input multiple output OTA-C filter. The 2004 IEEE Asia-Pacific Conference on Circuits and Systems, Tainan, pp. 1037–1039, (2004)Google Scholar
  19. [3.18]
    Chang, C., Al-Hashimi, B.M., Neil Ross, J.: Unified active filter biquad structures. IEE Proc. Circuits Devices Syst. 151(44), 273–277 (2004)CrossRefGoogle Scholar
  20. [3.20]
    Bhaskar, D.R., Singh, A.K., Sharma, R.K., Senani, R.: New OTA-C universal current-mode/transadmittance biquads. IEICE Electron. Expr. 2, 8–13 (2005)CrossRefGoogle Scholar
  21. [3.21]
    Chunhua, W., Ling, Z., Tao, L.: A new OTA-C current-mode biquad filter with single-input and multiple outputs. AEU Int. J. Electron. Commun. 62, 232–234 (2008)CrossRefGoogle Scholar
  22. [3.22]
    Biolek, D., Biolkova, V., Kolka, Z.: Universal current-mode OTA-C KHN biquad. Proc. World. Acad. Sci. Eng. Tech. 25, 289–292 (2007)Google Scholar
  23. [3.23]
    Chang, C.M., Pai, S.K.: Universal current-mode OTA-C biquad with the minimum components. IEEE Trans. Circuits Syst. I Fundam. Theory Appl. 47, 1235–1238 (2000)CrossRefGoogle Scholar
  24. [3.24]
    Kamat, D.V., Ananda Mohan, P.V., Gopalakrishna Prabhu, K.: Novel first-order and second-order current-mode filters using multiple-output operational transconductance amplifiers. Circuits Syst. Signal Process. 29, 553–576 (2010)zbMATHCrossRefGoogle Scholar
  25. [3.25]
    Bhaskar, D.R., Sharma, R.K., Singh, A.K., Senani, R.: New dual-mode biquads using OTAs. Frequenz 60, 11–12 (2006)CrossRefGoogle Scholar
  26. [3.26]
    Moschytz, G.S.: High-Q factor insensitive active RC network similar to the Tarmy-Ghausi circuit, but using single-ended operational amplifiers. Electron. Lett. 8, 458–459 (1972)CrossRefGoogle Scholar
  27. [3.27]
    Tarmy, R., Ghausi, M.S.: Very high Q, insensitive active RC networks. IEEE Trans. Circuit Theory CT-17, 358–366 (1970)CrossRefGoogle Scholar
  28. [3.28]
    Mulawka, J., Bialko, M.: Modifications of Tarmy-Ghausi active filter. Electron. Lett. 10(18), 380–381 (1974)CrossRefGoogle Scholar
  29. [3.29]
    Comer, D.J.: High-frequency narrow-band active filters. IEEE Trans. Circuits Syst. CAS-33(8), 838–840 (1986)CrossRefGoogle Scholar
  30. [3.30]
    Comer, D.T., Comer, D.J., Gonzalez, J.R.: A high-frequency integrable band pass filter configuration. IEEE Trans. Circuits Syst. II Analog Digit. Signal Process. 44(10), 856–861 (1997)CrossRefGoogle Scholar
  31. [3.31]
    Toker, S., Ozoguz, O., Cicekoglu, O., Acar, C.: Current-mode all-pass filters using current differencing buffered amplifier and a new high-Q band-pass filter configuration. IEEE Trans. Circuits Syst. II Analog Digit. Signal Process. 47, 949–954 (2000)CrossRefGoogle Scholar
  32. [3.32]
    Kamat, D.V., Ananda Mohan, P.V., Gopalakrishna Prabhu, K.: Current-mode operational transconductance capacitor biquad filter structures based on Tarmy-Ghausi active RC filter and second-order digital all-pass filters. IEE Circuits Devices Syst. 4, 346–364 (2010)CrossRefGoogle Scholar
  33. [3.33]
    Oppenheim, A.V., Schafer, R.W.: Digital processing of signals. Wiley, New York (2007)Google Scholar
  34. [3.34]
    Mitra, S.K., Hirano, K.: Digital all-pass networks. IEEE Trans. Circuits Syst. CAS-21, 688–700 (1974)CrossRefGoogle Scholar
  35. [3.35]
    Gray, A.H., Markel, J.D.: Digital lattice and ladder filter synthesis. IEEE Trans. Audio Electroacoust. AU-21, 491–500 (1973)MathSciNetCrossRefGoogle Scholar
  36. [3.36]
    Ananda Mohan, P.V.: Novel OTA-C filter structures using grounded capacitors. Proceedings of IEEE ISCAS, Singapore, pp. 1347–1350, (1991)Google Scholar
  37. [3.37]
    Sun, Y.: OTA-C filter design using inductor substitution and Bruton transformation methods. Electron. Lett. 34, 2082–2083 (1998)CrossRefGoogle Scholar
  38. [3.39]
    Hwang, Y.S., Liu, S.I., Wu, D.S., Wu, Y.P.: Table-based linear transformation filters using OTA-C technique. Electron. Lett. 30, 2021–2022 (1994)CrossRefGoogle Scholar
  39. [3.38]
    Dimopoulos, H.G., Constantinides, A.G.: Linear transformation active filters. IEEE Trans. Circuits Syst. 25, 845–852 (1978)CrossRefGoogle Scholar
  40. [3.40]
    Ramirez-Angulo, J., Sanchez-Sinencio, E.: High frequency compensated current-mode ladder filters using multiple output OTAs. IEEE Trans. Circuits Syst. II CAS-41, 581–586 (1994)CrossRefGoogle Scholar
  41. [3.41]
    Sun, Y., Fidler, J.K.: Structure generation and design of multiple-feedback OTA-grounded capacitor filters. IEEE Trans. Circuits Syst. I CAS-44, 1–11 (1997)Google Scholar
  42. [3.42]
    Chang, C.M., Al-Hashimi, B.M., Sun, Y., Ross, J.N.: New high-order filter structures using single-ended-input OTAs and grounded capacitors. IEEE Trans. Circuits Syst. I Regul. Pap. 51, 458–463 (2004)Google Scholar
  43. [3.43]
    Chang, C.M., Al Hashimi, B.M.: Analytical synthesis of current mode high order OTA-C filters. IEEE Trans. Circuits Syst. I Fundam. Theory Appl. 50(9), 1188–1192 (2003)CrossRefGoogle Scholar
  44. [3.44]
    Tu, S.H., Chang, C.M., Ross, J.N., Swamy, M.N.S.: Analytical synthesis of current-mode high-order single-ended-input OTA and equal-capacitor elliptic filter structures with the minimum number of components. IEEE Trans. Circuits Syst. I Fundam. Theory Appl. 54, 2195–2210 (2007)CrossRefGoogle Scholar
  45. [3.45]
    Chang, C.M., Hou, C.L., Chung, W.Y., Horng, J.W., Tu, C.K.: Analytical synthesis of high-order single-ended-input OTA grounded-C all-pass and band-reject filter structures. IEEE Trans. Circuits Syst. I Regul. Pap. 53, 489–498 (2006)CrossRefGoogle Scholar
  46. [3.46]
    Laber, C.A., Gray, P.R.: A 20 MHz sixth order BiCMOS parasitic-insensitive continuous-time filter and second order equalizer optimized for disk-drive readchannels. IEEE J. Solid-State Circuits 28, 462–470 (1993)CrossRefGoogle Scholar
  47. [3.47]
    Harrison, J., Weste, N.: A 500 MHz CMOS anti-alias filter using feed-forward op-amps with local common-mode feedback. IEEE International Solid-State Circuits Conference (ISSCC) Digest Technical Papers, 1, 132–483 (2003)Google Scholar
  48. [3.48]
    Tandri, B.K., Silva-Martinez, J.: A robust feed-forward compensation scheme for multistage operational transconductance amplifiers with no Miller capacitors. IEEE J. Solid-State Circuits SC-38, 237–243 (2003)CrossRefGoogle Scholar
  49. [3.49]
    Laxminidhi, T., Prasadu, V., Pavan, S.: Widely programmable high-frequency active RC filters in CMOS technology. IEEE Trans. Circuits Syst. I 56, 327–336 (2009)CrossRefGoogle Scholar
  50. [3.50]
    Abuelma’atti, M.T.: New minimum component electronically tunable OTA-C sinusoidal oscillators. Electron. Lett. 25, 1114–1115 (1989)CrossRefGoogle Scholar
  51. [3.51]
    Senani, R., Amit Kumar, B.: Linearly tunable Wien Bridge oscillator realized with operational transconductance amplifiers. Electron. Lett. 25, 19–21(1989)CrossRefGoogle Scholar
  52. [3.52]
    Senani, R.: New electronically tunable OTA-C sinusoidal oscillator. Electron. Lett. 25, 286–287 (1989)CrossRefGoogle Scholar
  53. [3.53]
    Senani, R., Tripathi, M.P., Bhaskar, D.R., Banerjee, A.K.: Systematic generation of OTA-C sinusoidal oscillators. Electron. Lett. 26, 1457–1459 (1990)CrossRefGoogle Scholar
  54. [3.54]
    Linares-Barranco, B., Rodriguez-Vazquez, A., Sanchez-Sinencio, E., Huertas, J.L.: CMOS OTA-C high-frequency sinusoidal oscillators. IEEE J. Solid-State Circuits 26, 160–165 (1991)CrossRefGoogle Scholar
  55. [3.55]
    Odame, K.M., Hasler, P.: Theory and design of OTA-C oscillators with native amplitude limiting. IEEE Trans. Circuits Syst. I Regul. Pap. 56, 40–50 (2009)MathSciNetCrossRefGoogle Scholar
  56. [3.56]
    Galan, J., Carvajal, R.G., Torralba, A., Munoz, F., Ramirez-Angulo, J.: A low-power low-voltage OTA-C sinusoidal oscillator with a large tuning range. IEEE Trans. Circuits Syst. I Regul. Pap. 52, 283–291 (2005)CrossRefGoogle Scholar
  57. [3.57]
    Linares-Barranco, B., Serrano-Gotarredona, T., Ramos-Martos, J., Ceballos-Caceres, J., Mora, J.M., Linares-Barranco, A.: A precise 90° quadrature OTA-C oscillator tunable in the 50–130-MHz range. IEEE Trans. Circuits Syst. I Regul. Pap. 51, 649–663 (2004)CrossRefGoogle Scholar
  58. [3.58]
    Ahmed, R.F., Awad, I.A., Soliman, A.N.: A transformation method from voltage-mode Op-Amp RC circuits to current-mode Gm-C circuits. Circuits Syst. Signal Process. 25, 609–626 (2006)MathSciNetzbMATHCrossRefGoogle Scholar
  59. [3.59]
    Bhattacharyya, B.B., Swamy, M.N.S.: Network transposition and its application in synthesis. IEEE Trans. Circuit Theory CT-18, 394–397 (1971)CrossRefGoogle Scholar
  60. [3.60]
    Director, S.W., Rohrer, R.A.: The generalized adjoint network and network sensitivities. IEEE Trans. Circuit Theory CT-16, 318–323 (1969)CrossRefGoogle Scholar
  61. [3.61]
    Swamy, M.N.S., Bhushan, C., Bhattacharyya, B.B.: Generalized dual transposition and its applications. J. Franklin Inst. 301, 465–476 (1976)MathSciNetzbMATHCrossRefGoogle Scholar
  62. [3.62]
    Mahattnakul, J., Toumazou, C.: Current-mode versus voltage-mode Gm-C biquad filters: what the theory says. IEEE Trans. Circuits Syst. II 45, 173–186 (1998)CrossRefGoogle Scholar
  63. [3.63]
    Ramirez-Angulo, J., Sanchez-Sinencio, E.: Active compensation of operational transconductance amplifier filters using partial positive feedback. IEEE J. Solid-State Circuits SC-25, 1024–1028 (1990)CrossRefGoogle Scholar
  64. [3.64]
    Ananda Mohan, P.V.: Current-mode VLSI Analog Filters. Birkhauser, Boston (2003)zbMATHCrossRefGoogle Scholar

Further Reading

  1. Deliyannis, T., Sun, Y., Fidler, J.K.: Continuous-Time Active Filter Design. CRC Press, Florida (1999)Google Scholar
  2. Kallam, P., Sanchez-Sinencio, E., Karsilayan, A.I.: An enhanced adaptive Q-tuning scheme for a 100-MHz fully symmetric OTA-based bandpass filter. IEEE J. Solid-State Circuits 38(4), 585–593 (2003)CrossRefGoogle Scholar
  3. Toumazou, C., Lidgey, J., Haigh, D. (eds.): Analogue IC Design: The Current-Mode Approach. IEE, London (1990)Google Scholar
  4. Swamy, M.N.S., Raut, R.: Realization of gm-C current-mode filters from associated (gm-C) voltage mode filters. Proceedings of the 45th Midwest Symposium on Ciruits and Systems, Tulsa, OK, Part II, 625–628 (2002)Google Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Electronics Corporation of India, Ltd.BangaloreIndia

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