Analog switches?

[James Husted]

If noise is the problem you have with CMOS switches, here's a trick that was
put to use in a very old product made at a company I used to work for. To
lower the noise from the cmos switch being used, don't have the signal go
through the switch. The layout was something like :

 signal in ----- resistor --------+-------- resistor -------- signal out
                                  |
                                  |
                               switch
                                  |
                                  |
                               ground

The signal gets shorted to ground to turn it off, and when on doesn't go
through the switch and is less noisy as a result. Don't know if it will
help, but it's cheap to try out. Add a trimmer and it can be a variable
preset attenuation.
-James

    |_e_/   James Husted
      )     The Ersatz Planet - graphics and sound design
    ~\/\    james at ersatzplanet.com
       /    www.ersatzplanet.com
            webmaster at ersatzplanet.com

> From: The Proteus <proteus at ugwarehouse.org>
> Date: Wed, 15 Mar 2000 13:14:04 -0800 (PST)
> To: synth-diy at node12b53.a2000.nl
> Subject: Analog switches?
> 
> All,
> 
> I've been in pursuit of decent analog switches for quite some time
> now, as I have been previously unsatisfied with the results when using
> CMOS 4052's and 4066's. The best compromise I've seen so far is the
> ADG333A from Analog Devices, but this is still a bit pricey ($5.12 in low
> quantity) for my tastes. Anyone have any other analog and/or JFET switch
> topologies they'd like to share with me?
> 
> Thanks,
> 
> The Proteus
> 
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