Design of Two-Stage Fully-Differential Operational Transconductance Amplifier Using a Standard 0.35µm CMOS Process

Tanya Vanessa Abaya, Frederick Ray I. Gomez

Abstract


The paper presents a design of a two-stage fully-differential operational transconductance amplifier (OTA) for a 10-bit 40-Msamples/s Nyquist rate analog-to-digital converter (ADC) using  a standard 0.35µm complementary metal-oxide semiconductor (CMOS) process.  A telescopic cascode topology is implemented as main stage, with common source amplifiers as output stage for the differential outputs. The open loop amplifier achieved a gain of 108dB, while the closed loop gain is at 12dB with settling time of less than 11ns for an accuracy of 0.5%.  Total output noise achieved is 63.4uVrms.  Loop unity gain bandwidth is 205MHz with phase margin of 77.6°. The design has a dynamic range of 88.3dB, and power consumption of 26.6mW from a 3V supply.


Keywords


OTA; CMOS; amplifier; ADC

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References


M. Hajimorad and M. Muh, “The Design of a High-Dynamic Range Fully-Differential OTA,” Class Project: EECS 240 UC Berkeley, 2000.

Cadence Design Systems, Inc., “Custom IC / analog / RF design – circuit design”, https://www.cadence.com /content/cadence-www/global/en_US/home/tools/ custom-ic-analog-rf-design/circuit-design.html

B. Razavi, “Design of analog CMOS integrated circuits,” New York, USA: McGraw-Hill, 2001.

P.R. Gray, P.J. Hurst, S.H. Lewis, and R.G. Meyer, “Analysis and design of analog integrated circuits,” 5th ed., New Jersey, USA: John Wiley & Sons, Inc., January 2009.

C. Bowick, C. Ajluni, and J. Blyler, “RF circuit design,” 2nd ed., Newton, Massachusetts, USA: Newnes, November 2007.

B. Razavi, “Phase-locking in high-performance systems – from devices to architectures,” USA: Wiley-IEEE Press, 2003.

T. Lee, “The design of CMOS radio-frequency integrated circuits,” Cambridge: Cambridge University Press, 1998.

B. Razavi, RF Microelectronics, 2nd ed., Prentice Hall Press, Upper Saddle River, New Jersey, USA, 2011.




DOI: https://doi.org/10.24203/ajet.v7i1.5680

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