Spehro Pefhany wrote...

>What would the consequences be of going to 20K on the midrange 10-bit =
A/D
>input? I've read the reference manual and the data sheet. If the input =
is
>bypassed with a 0.1uF or something of that ilk, it seems to be primarily
>limited by the worst case leakage current on the input vs. guaranteed
>accuracy. I'm willing to lose 1 bit or 1.5 bits in the A/D, and high
>temperature operation is not required.
>
>Any thoughts on this?
>
>I'd normally put an op-amp in there without much thought, but the =
quantities
>are such that thought will be well rewarded if a few cents can be =
snipped.

The only other error I can see you getting, other than the drop across
your 20K resistor due to input leakage, would be a scale factor error
that can occur if you have the input bypassed and are sampling it at a
high rate.  But if you're not looking for full 10-bit accuracy I can't
see this as a big issue. =20

Dave

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