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g m ‐Extraction for rail‐to‐rail input stage linearization
Author(s) -
Palma F.,
Durante S.
Publication year - 2005
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.338
Subject(s) - transconductance , operational transconductance amplifier , feed forward , amplifier , operational amplifier , control theory (sociology) , linearization , signal (programming language) , electronic engineering , voltage , computer science , feedback linearization , function (biology) , electrical engineering , engineering , transistor , control (management) , control engineering , nonlinear system , physics , cmos , artificial intelligence , quantum mechanics , evolutionary biology , biology , programming language
Abstract Transconductance of rail‐to‐rail input stages in low‐voltage operational amplifiers depends on the presence of a large common mode input signal. Corrections must be implemented in order to correct it. Nevertheless, techniques actually used, based on switching or feedforward, still give relevant deviation from the constant transconductance condition. In this paper we present a new architecture based on extraction and feedback to the gain control, directly of the value of the transconductance of the amplifier to be controlled. This quantity does not contain the signal to be amplified, and thus once fed back, it does not affect the overall stage gain. A ‘reciprocal’ circuit, which performs the 1/ x mathematical function, is introduced in order to achieve this extraction. Copyright © 2005 John Wiley & Sons, Ltd.