The readout of high impedance sensors and sampled voltage references [1]
requires amplifiers with both low offset and low input current. Chopper amplifiers
can achieve low offset, but the switching of their input chopper gives rise to
significant input current (40 to 110pA) [2-4]. Auto-zero (AZ) amplifiers require
less input switching, but exhibit more voltage noise. However, ping-pong
amplifiers continuously swap two auto-zeroed input stages, leading to more
switching [5,7]. In this work, an AZ stabilized topology is proposed, in which a
single amplifier is always present in the signal path. Only one input switch is
required, resulting in an input current of 0.6pA (max), a 66× improvement on the
state-of-the art [4]. Furthermore, a digitally assisted offset-reduction scheme
reduces its low-frequency (LF) noise to the theoretical √5× limit. It also achieves
a state-of-the-art maximum offset of 0.6μV.
Original languageEnglish
Title of host publication2018 IEEE International Solid-State Circuits Conference, ISSCC 2018
Subtitle of host publicationDigest of Technical Papers
PublisherIEEE
Pages50-52
Number of pages3
ISBN (Electronic)978-1-5090-4940-0
ISBN (Print)978-1-5386-2227-8
DOIs
Publication statusPublished - 2018
Event65th IEEE International Solid-State Circuits Conference, ISSCC 2018 - San Francisco, United States
Duration: 11 Feb 201815 Feb 2018

Publication series

NameDigest of Technical Papers
Volume61
ISSN (Print)0193-6530

Conference

Conference65th IEEE International Solid-State Circuits Conference, ISSCC 2018
CountryUnited States
CitySan Francisco
Period11/02/1815/02/18

ID: 45740900