On Wed, 16 Oct 2002, Bob Blick wrote:

*>>  With few mA it couldn't raise the +5v power suply.
*>>  a diode pointing from the PIC to the input eats some
*>>  voltage, thus reducing bottom threshold to switch Schmitt
*>>  Trigger. External source might be unable to provide this
*>
*>OK, so how about just one part - a series resistor, high in value. If you
*>need to drive with open collector, add a pullup resistor before the series
*>resistor.
*>
*>There's no universal way to do this. There are too many PICs, too many
*>different pins on the PICs, etc...

Yes there is. The clamping circuit I posted on the piclist before will do
this, will not rise the Vcc line, will maintain the pic inputs within
manufacturer specs at all times.

Peter

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