S&H

[Gene Zumchak]

Tomg and Guys,

    One classic S/H uses two op amps, FET ones preferably, both are wired as
voltage followers, the output of the second feeds the inverting input of the
first.  The second just feeds back to its own inverting input.  Between the
first and second is a switch and the cap to ground.

    National puts that all in an 8-pin package for you.  Its called the LF398.
Digikey lists it for $3.33 in onesies.  Looks like the simplest, and maybe the
cheapest solution.

Gene Z.

terry michaels wrote:

> Message text written by Martin Czech
> >But if you do all this, you coulr really use a adc/dac pair,
> maybe with eprom between, this gives a qunatizer.
> <
>
> Hi Martin
>
> Many DACs are double buffered internally, so you don't need an eprom or any
> other external memory.  Just toggle the r ight pin on the DAC and it will
> hold the last input word.
>
> Terry Michaels