To read and store takes two functions, S&H then convert right?

So reading the 877 data sheet, it takes on the average 19.27uS to capture
the analog data.  Now if this is a sine wave and you are looking for the
peak value, the switch will close, the cap will charge for the 19.27 uS then
the switch opens.  The value holds there, so then you run the conversion
which depends on the speed of the clock and what you choose to use.

Question is....when the sample & hold circuit is running, its not a snapshot
of any particular time (less you use a flash A/D I suppose)but essently will
be the peak value of the sine wave even if the aquisition time occurs prior
to and after the peak.  Its not going to drain the cap once the negative
quadrant of the peak occurs, but simply hold the peak charge that it was
given (thats the question).  Elsewise, if you want to sample the peak, you
have to know exactly when the switch closes and be sure the peak occurs
right before the switch opens, and that is also going to depend on
temperature, etc.



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