Jan-Erik Soderholm wrote:

> The "holding cap" is disconnected from the input during the conversion
> time. After the conversion it is automaticly connected to the input pin
> again. Now, if the voltage on the input pin has changed conciderably
> during the conversion, I'd guess that you need a new acquisition time to
> let the holding cap re-charge to the new input voltage, before starting
> a new conversion, not ? 

Yes. That's why I said "usually". This of course means that there /are/
(IMO rare) conditions where this is not the case.

I'd venture a guess and say that in most cases when only one input is read
there is a suitable combination of slow enough input changes and the
program's reaction time to the end of conversion signal that the hold cap
has enough time to charge before the next conversion. 

Especially when we are talking about mains wave forms. 

Gerhard

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