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From: michael@otago.ac.nz
Newsgroups: sci.electronics
Subject: Re: CMOS Analog Switches
Message-ID: <1991Mar8.094025.135@otago.ac.nz>
Date: 7 Mar 91 22:08:29 GMT
References: <5292@umbc3.UMBC.EDU>
Organization: University of Otago, Dunedin, New Zealand
Lines: 24

In article <5292@umbc3.UMBC.EDU>, hack@umbc5.umbc.edu writes:
> 
>       I am tring to build a audio amplifier and I wish to have
> it electronically switched (as few mechanical switches as
> possible).  What I was concidering is using CMOS bilateral
> switches to handle this.  What I am concerned is they might
> produce a great deal of distortion to the signals.  Now I know
> that audio signals are typically 20-20kHz, still I don't know
> if that would be a problem.
> 

Electronics Australia had a 100W amp design that did this in I think 1988
called the Studio 200. It used 4066's coupled with BiFET op-amps to keep the
current through the CMOS switch down; apparently distortion arises only when
you try to draw current through the things. It worked, or at least they claimed
some fairly impressive figures for it...



Michael(tm) Hamel, Computing Services Centre, University of Otago, New Zealand

LITTLE URSWICK (n.)                
The member of any class who most inclines a teacher towards the view that
capital punishment should be introduced in schools.