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Article: Sample-and-hold amplifier holds the difference of two inputs.(Book review)
- Article from:
- EDN
- Article date:
- July 24, 2008
- Author:
CopyrightCOPYRIGHT 2008 Reed Business Information, Inc. (US). This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Marián Eatofka, Slovak University of Technology, Bratislava, Slovakia
Edited by Martin Rowe and Fran Granville
You can fulfill a requirement for sampling the difference of two signals in two classic ways. You can subtract the two input signals with an instrumentation amplifier whose output connects to an input of a classic sample-and-hold amplifier. Despite the positive feature of needing no external resistors for a gain-of-one differencing instrumentation amplifier, this approach suffers from high relative output distortion when the inputs are of the same polarity and close in magnitude. In such a case, the difference of two input signals is ...