Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters

M. R. Valero, Antonio López-Martín, Alejandro Román-Loera, Jaime Ramírez-Angulo, Ramon G. Carvajal

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

This paper introduces a simple approach for the implementation of rail-to-rail operational amplifiers (OpAmps) with constant g m using only one differential input pair. It is based on the utilization of switched voltage followers that introduce a DC level shift when the OpAmp's common mode input voltage is lower than the headroom of the input differential pair (DP). Additional circuitry is introduced in order to make the DP tail current insensitive to common mode input voltage variations. This improves CMRR and PSRR and reduces g m variations. The additional circuitry increases power dissipation by less than 20%. Simulation results are presented that verify rail-to-rail operation with ±1.65 supply voltages in 0.5μm CMOS technology.
Original languageEnglish
Title of host publication2015 IEEE International Symposium on Circuits and Systems (ISCAS)
Place of PublicationUSA
PublisherIEEE
Pages2461-2464
Number of pages4
ISBN (Electronic)978-1-4799-8391-9
DOIs
Publication statusPublished - 30 Jul 2015
EventISCAS 2015: IEEE International Symposium on Circuits and Systems - Lisbon, Spain
Duration: 24 May 201527 May 2015

Conference

ConferenceISCAS 2015: IEEE International Symposium on Circuits and Systems
CountrySpain
CityLisbon
Period24/05/1527/05/15

Fingerprint

Operational amplifiers
Rails
Electric potential
Energy dissipation

Keywords

  • CMOS analogue integrated circuits
  • operational amplifiers
  • DC level shift
  • DP tail current
  • common mode input voltage variations
  • constant g<sub>m</sub> rail-to-rail CMOS opamp
  • differential input pair
  • power dissipation
  • size 0.5 mum
  • switched level shifters
  • switched voltage followers
  • CMOS integrated circuits
  • CMOS technology
  • Current control
  • Logic gates
  • Rails
  • Threshold voltage
  • Transistors
  • Amplifiers
  • CMOS Analog integrated circuits
  • low-voltage low power design
  • rail-to-rail amplifiers

Cite this

Valero, M. R., López-Martín, A., Román-Loera, A., Ramírez-Angulo, J., & Carvajal, R. G. (2015). Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters. In 2015 IEEE International Symposium on Circuits and Systems (ISCAS) (pp. 2461-2464). USA: IEEE. https://doi.org/10.1109/ISCAS.2015.7169183

Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters. / Valero, M. R.; López-Martín, Antonio; Román-Loera, Alejandro; Ramírez-Angulo, Jaime; Carvajal, Ramon G.

2015 IEEE International Symposium on Circuits and Systems (ISCAS). USA : IEEE, 2015. p. 2461-2464.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Valero, MR, López-Martín, A, Román-Loera, A, Ramírez-Angulo, J & Carvajal, RG 2015, Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters. in 2015 IEEE International Symposium on Circuits and Systems (ISCAS). IEEE, USA, pp. 2461-2464, ISCAS 2015: IEEE International Symposium on Circuits and Systems, Lisbon, Spain, 24/05/15. https://doi.org/10.1109/ISCAS.2015.7169183
Valero MR, López-Martín A, Román-Loera A, Ramírez-Angulo J, Carvajal RG. Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters. In 2015 IEEE International Symposium on Circuits and Systems (ISCAS). USA: IEEE. 2015. p. 2461-2464 https://doi.org/10.1109/ISCAS.2015.7169183
Valero, M. R. ; López-Martín, Antonio ; Román-Loera, Alejandro ; Ramírez-Angulo, Jaime ; Carvajal, Ramon G. / Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters. 2015 IEEE International Symposium on Circuits and Systems (ISCAS). USA : IEEE, 2015. pp. 2461-2464
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title = "Constant gm rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters",
abstract = "This paper introduces a simple approach for the implementation of rail-to-rail operational amplifiers (OpAmps) with constant g m using only one differential input pair. It is based on the utilization of switched voltage followers that introduce a DC level shift when the OpAmp's common mode input voltage is lower than the headroom of the input differential pair (DP). Additional circuitry is introduced in order to make the DP tail current insensitive to common mode input voltage variations. This improves CMRR and PSRR and reduces g m variations. The additional circuitry increases power dissipation by less than 20{\%}. Simulation results are presented that verify rail-to-rail operation with ±1.65 supply voltages in 0.5μm CMOS technology.",
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