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

M. R. Valero, Antonio Lopez-Martin, Alejandro Roman-Loera, Jaime Ramirez-Angulo, Ramon G. Carvajal

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

2 Citations (Scopus)

Abstract

This paper introduces a simple approach for the implementation of rail-to-rail operational amplifiers (OpAmps) with constant gm 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 gm 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 2015
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Pages2461-2464
Number of pages4
ISBN (Electronic)9781479983919
DOIs
Publication statusPublished - 27 Jul 2015
EventIEEE International Symposium on Circuits and Systems, ISCAS 2015 - Lisbon, Portugal
Duration: 24 May 201527 May 2015

Publication series

NameProceedings - IEEE International Symposium on Circuits and Systems
Volume2015-July
ISSN (Print)0271-4310

Conference

ConferenceIEEE International Symposium on Circuits and Systems, ISCAS 2015
CountryPortugal
CityLisbon
Period24/05/1527/05/15

Keywords

  • Amplifiers
  • CMOS Analog integrated circuits
  • low-voltage low power design
  • rail-to-rail amplifiers

Fingerprint

Dive into the research topics of 'Constant g<sub>m</sub> rail-to-rail CMOS OpAmp with only one differential pair and switched level shifters'. Together they form a unique fingerprint.

Cite this