Journal Article

A start-up assisted fully differential folded cascode opamp

Abstract

This paper explains the hidden positive feedback in the two-stage fully differential amplifier through external feedback resistors, and possible DC latch-up during the amplifier start-up. The biasing current selection among the cascode branches have been explained intuitively, With reference to previous literature. To avoid the latch-up problem irrespective of the transistor bias currents a novel, hysteresis based start-up circuit is proposed. An 87dB, 250MHz unity gain bandwidth amplifier has been developed in 65nm CMOS Technology and post-layout simulations demonstrate no start-up failures out of 1000 Monte-Carlo (6-Sigma) simulations. The circuit draws 126uA from a 1.2V supply and occupies the 2184um2 area.

Attached files

Authors

Nagulapalli, Rajasekhar
Hayatleh, Khaled
Barker, Steve
Yassine, Bilal
Zourob, Saddam
Raparthy, S.
Yassine, Nabil

Oxford Brookes departments

Faculty of Technology, Design and Environment\School of Engineering, Computing and Mathematics

Dates

Year of publication: 2018
Date of RADAR deposit: 2018-10-15

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This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License

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Related resources

This RADAR resource is the Accepted Manuscript of A start-up assisted fully differential folded cascode opamp