Mark Rages wrote:
> I've tried exceeding the 10k impedance before and had
> a problems with noisy readings. =A0 Lower impedance made
> it all better.

The problem was with your design. You could have achieved less noisy
readings with just proper design.


> I think the 10k rating is there for a reason.

Sure it is. And the reason(s) was/were pointed out numerous times in
this thread.


> It is an inconvenient spec and I'm sure Microchip would
> revise it if the workaround was as simple as a longer
> acquisition time.

It was pointed out many times already that the workaround was not "as
simple as a longer acquisition time".

Re-read specs, please (pay attention to "pin leakage specs" phrase):
***
MidRange Docs
Section 23. 10-bit A/D Converter

Note 3: The maximum recommended impedance for analog sources is 10 k.
This is required to meet the pin leakage specification.
***

-- =

http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist