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From: sgm@otter.hpl.hp.com (Steve Methley)
Newsgroups: sci.electronics
Subject: Re: Good Clamping Circuit
Message-ID: <72020002@otter.hpl.hp.com>
Date: 11 Mar 91 10:31:56 GMT
References: <1991Mar06.181426.10500@cdsmn.mn.org>
Organization: Hewlett-Packard Laboratories, Bristol, UK.
Lines: 19

In article <1991Mar06.181426.10500@cdsmn.mn.org> plate@cdsmn.mn.org (Doug
Plate) writes:

> I'm looking for a simple circuit that will clamp the output of a summing
> amp to 5 volts.........

Why not use an op-amp whose output is designed to be clamped?  You'll find that
the RCA3140 has this feature, along with a few others I can't recall just now.
Details in RCA databooks.......  (A zener from pin 8 to ground, clamped o/p
level is zener voltage less two diode drops)

Do bear in mind that if you clamp the output of a feedback circuit you lose the
effect of the feedback!  Incidentally that's why the approach I detail is good,
because it stops the o/p drivers saturating, regardless of input.  This is
important if speed/recovery from overdrive is an issue.

Cheers,
Steve.
(personal opinions)