PDM power from ADC

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Sam Wetterlin
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Joined: Sat Apr 28, 2018 6:48 pm

PDM power from ADC

Post by Sam Wetterlin » Mon Nov 24, 2008 9:55 pm

This posting relates to the original PDM board, and probably the ones

from the ExpressPCB group buy, so if you're getting one from Cash, you

should probably ignore this for the moment. Cash's PDM will have a

number of changes from the original.



The website explains possible modifications designed to equalize the

ADC reference voltage and the voltage supply to the final F/F on the

PDM board. Of those, there doesn't seem to be any good reason to use

anything other than Option 3. It uses the ADC regulator output to

power that F/F. But I think one step is missing. If the ADC 5V is run

to PDM P2 Pin 1, it ends up being attached also to the PDM regulator.

I think the trace between FB2 and C5 needs to be cut in order to use

this option.



Sam W.

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