On Fri, Apr 27, 2012 at 3:20 PM, Harold Hallikainen
<harold@hallikainen.org>wrote:

> In my opinion, there are two things that set the maximum source resistanc=
e
> driving a PIC ADC. The first is the hold capacitor charge time. If you ar=
e
> measuring a near DC voltage and not using the PIC input multiplexer to
> read multiple ADC inputs, this should have no effect. The source
> resistance and the input hold capacitor form a low pass filter, but does
> not introduce a steady error.
>
> If the input is multiplexed, this becomes an issue. You'll see crosstalk
> between inputs as it takes time for the input holding capacitor to change
> voltage from one channel to another.
>
>
>
It's been forever and a day ago since I read that section, but I thought
the multiplexer
specifically discharged the sample & hold capacitor between conversions
specifically
to prevent this type of cross talk.

Or is my memory going like my hair?

-Denny
--=20
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