[sdiy] S&H

[Richard Wentk]

At 09:31 16/01/2003 +0000, Paul Maddox wrote:

>Im not worried about droop, as I plan to update each channel every 10uS but
>I have only about 200nS of time in which to load the S&H.
>for example the max5168 datasheet say it has an min aquistion time of 250nS,
>so I *MIGHT* get away with it..

I'd doubt this. You'd be building something which leaves a negative amount 
of room for component tolerances. That's not usually a good idea.

Why not buffer the incoming data with its own independent (dual-port?) 
memory, so you can stretch out the 32 channel update cycle over the whole 
of the 10us? It would be a bit of a pain to design but at least you'd be in 
digital land where things mostly have hard edges, and not trying to deal 
with the problem in a fuzzy analogue way.

I don't know how you're driving the S&Hs or what you're driving them with, 
but this might make the specifications for your software more relaxed too.

Richard