Research PaperNo Access

A Positive Feedback-Based Op-Amp Gain Enhancement Technique for High-Precision Applications

School of Engineering, Computing and Mathematics, Oxford Brookes University, Wheatley Campus, Wheatley, Oxford, OX33 1HX, UK

E-mail Address: 19044568@brookes.ac.uk

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Khaled Hayatleh

https://orcid.org/0000-0003-0149-1772

School of Engineering, Computing and Mathematics, Oxford Brookes University, Wheatley Campus, Wheatley, Oxford, OX33 1HX, UK

E-mail Address: khayatleh@brookes.ac.uk

Corresponding author.

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, and

Steve Barker

School of Engineering, Computing and Mathematics, Oxford Brookes University, Wheatley Campus, Wheatley, Oxford, OX33 1HX, UK

E-mail Address: stevebarker@brookes.ac.uk

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https://doi.org/10.1142/S0218126620502205Cited by:10 (Source: Crossref)

Abstract

A power-efficient, voltage gain enhancement technique for op-amps has been described. The proposed technique is robust against Process, Voltage and Temperature (PVT) variations. It exploits a positive feedback-based gain enhancement technique without any latch-up issue, as opposed to the previously proposed conductance cancellation techniques. In the proposed technique, four additional transconductance-stages (gm stages) are used to boost the gain of the main gm stage. The additional gm stages do not significantly increase the power dissipation. A prototype was designed in 65nm CMOS technology. It results in 81dB voltage gain, which is 21dB higher than the existing gain-boosting technique. The proposed op-amp works with as low a power supply as 0.8V, without compromising the performance, whereas the traditional gain-enhancement techniques start losing gain below a 1.1V supply. The circuit draws a total static current of 295 $μ$ A and occupies 5000 $μ$ m² of silicon area.

This paper was recommended by Regional Editor Piero Malcovati.

Keywords:

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