[sdiy] SYASH up!

[JH.]

> >Just wondering if an OTA switch has any inherent advantages over a more
> >traditional CMOS switch like the 4066 or 405x types.
>
> I didn't look into detail at the difference.  The leakage, charge transfer
> and series R of the switch would have to be looked at carefully.  Also
> voltage limitations.
>
> For me, a big advantage of using the OTA switch is that I bought large
> batches of OTAs and selected out the best performing ones for critical
> applications, so I have a big stash I can use for less critical
> applications.  I consider them as pretty much free for applications like
> this.  :-)


Another advantage of the OTA approach is that you can use the same
configuration
as a voltage controlled glide / lag circuit, by only using a different
control signal:
* small, variable Iabc current for Glide,
* high, pulsed Iabc current for S&H operation.

I used this in the Synthi Clone, where real estate (matrix rows and colums)
was limited,
and a double function module was welcome.

http://www.oldcrows.net/%7Ejhaible/tonline_stuff/jh_sc_shg.gif

JH.