National Academy Science Letters

, Volume 41, Issue 1, pp 41–45 | Cite as

A High Gain, Bulk Driven Operational Transconductance Amplifier (OTA) for Wireless Body Area Networks

  • Shabbir Majeed Chaudhry
  • Umair Munir Minhas
  • Farhat Abbas
Short Communication


This paper presents a bulk driven operational transconductance amplifier (OTA) operating in weak inversion region. The OTA is designed and implemented in 1P-9M Standard UMC 90 nm CMOS Process, and achieves a gain of 94.4 dB and a unity gain bandwidth of 48.97 MHz. Positive feedback, gm boosted, source degeneration is employed at the input of bulk driven differential pair of the amplifier. An NMOS differential pair is used at the output stage to enhance the gain as well as the bandwidth. The OTA consumes power as low as 57 nW. Comparison with the previously reported designs is made on the basis of gain, noise power spectral density and bandwidth. The results show significant improvement in the performance of the proposed OTA as compared to previously reported designs. The effective chip area of this OTA is 0.0147 mm2.


Bulk driven OTA Weak inversion Differential pairs Low voltage Low power 90 nm CMOS 


  1. 1.
    Zuo L, Islam SK (2013) Low-voltage bulk-driven operational amplifier with improved transconductance. IEEE Trans Circuits Syst I 60:2084–2091CrossRefGoogle Scholar
  2. 2.
    Ferreira LHC, Sonkusale SR (2014) A 60-dB gain OTA operating at 0.25-V power supply in 130-nm digital CMOS process. IEEE Trans Circuits Syst I 99:1–9Google Scholar
  3. 3.
    Ferreira LHC, Sonkusale SR (2012) Gm enhancement for bulkdriven sub-threshold differential pair in nanometer CMOS process. In: Proceedings of IEEE subthreshold microelectronics conference, USA, pp 1–3Google Scholar
  4. 4.
    Tsividis YP, McAndrew C (2010) Operation and modeling of the MOS transistor. Oxford University Press, New YorkGoogle Scholar
  5. 5.
    Ferreira LHC, Pimenta TC, Moreno RL (2007) An Ultra-low-voltage ultra-low-power CMOS Miller OTA with rail-to-rail input/output swing. IEEE Trans Circuits Syst II 54:843–847CrossRefGoogle Scholar
  6. 6.
    Chatterjee S, Tsividis Y, Kinget P (2005) 0.5-V analog circuit techniques and their application in OTA and filter design. IEEE J Solid State Circuits 40:2373–2387CrossRefGoogle Scholar
  7. 7.
    Carrillo JM, Torelli G, Pérez-Aloe R, Duque-Carrillo JF (2007) 1-V rail-to-rail CMOS opamp with improved bulk-driven input stage. IEEE J Solid State Circuits 42:508–517CrossRefGoogle Scholar
  8. 8.
    Raikos G, Vlassis S (2011) Low-voltage bulk-driven input stage with improved transconductance. Int J Circuit Theory Appl 39:327–339CrossRefGoogle Scholar
  9. 9.
    Libin Y, Steyaert M, Sansen W (2003) A 0.8-V, 8-µW, CMOS OTA with 50-dB gain and 1.2-MHz GBW in 18-pF load. In: Proceedings of European solid-state circuits conference, pp 297–300Google Scholar
  10. 10.
    Stockstad T, Yoshizawa H (2002) A 0.9-V 0.5 rail-to-rail CMOS operational amplifier. IEEE J Solid State Circuits 37:286–292CrossRefGoogle Scholar
  11. 11.
    Lehmann T, Cassia M (2001) 1-V power supply CMOS cascode amplifier. IEEE J Solid State Circuits 36:1082–1086CrossRefGoogle Scholar

Copyright information

© The National Academy of Sciences, India 2018

Authors and Affiliations

  • Shabbir Majeed Chaudhry
    • 1
  • Umair Munir Minhas
    • 1
  • Farhat Abbas
    • 2
  1. 1.University of Engineering and Technology, TaxilaTaxilaPakistan
  2. 2.NXP SemiconductorsEindhovenNetherlands

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