Analog Integrated Circuits and Signal Processing

, Volume 74, Issue 2, pp 399–407 | Cite as

Linearity improvement of source degenerated transconductance amplifiers

  • Sougata Kumar Kar
  • Siddhartha Sen


Mobility degradation is predominant in submicron CMOS technology. The effect of this mobility reduction in a linear operational transconductance amplifier (OTA) with signal attenuation and source degeneration is examined in this study. Theoretical analysis shows that the cubic non-linearity in the attenuator helps to improve the linearity of the source degenerated transconductor by partial cancellation of the harmonic distortion component. Such a linear transconductor and a third order low pass filter based on this linear OTA are fabricated in UMC 180 nm CMOS process technology. Experimental results show that third order intermodulation distortion of the linear OTA is less than −60 dB for 500 mVpp differential input signal while for 2 % transconductance variation the linear range is about 1.2 Vpp. The linear transconductor consumes only 0.45 mW of power with 1.8 V supply.


Attenuation Factor Differential Pair Input Transistor Operational Transconductance Amplifier Distortion Component 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Authors would like to acknowledge the financial support from Department of Information Technology (DIT), Government of India for fabrication of the chip.


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© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  1. 1.Department of Electrical EngineeringIndian Institute of TechnologyKharagpurIndia

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