Suppose you are transiting from voltage level A to voltage level B. If
the signal goes past B then settles back to B, probably with some
oscillations around B, you have overshoot. If the signal doesn't make it
to B, or gets to B some time later than you desired you have undershoot.
If the signal gets to B without going over or under you have the ideal
condition, or from control theory, a signal that is critically damped.
To further confuse things, overshoot implies under-damping and
undershoot implies over-damping
Larry Barnes
Symbios Inc.
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From: Mike Mayer[SMTP:[email protected]]
Sent: Monday, February 23, 1998 3:52 PM
To: [email protected]
Subject: Re: [SI-LIST] : Overshoot/Undershoot
=Alas, 'tis true. For too many years the digital crowd, having
=heard the term 'undershoot' but never really worked with it,
=assumed that it was what is known more precisely, negative-going
=overshoot. Books, articles, and instrumentation all made
=this usage the only one known to many young and impressionable
=engineers.
So for those of us who have only heard "undershoot" applied to
negative-going overshoot, what is the correct definition of
undershooot?
--
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Mike Mayer Artesyn Technologies - Communication Products
Group
http://www.artesyn.com
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