Wouter van Ooijen wrote:
> Note that there will also be protection diode current through your
> progger-PIC when you run the target at 6.0 Volt (max for a 16C84), or
> are you running the progger PIC at 5.5 and limiting the Vhigh to 5.5?

The circuit can adjust Vdd up to 6V, but so far I've only used it at 5.5V.
Again however, the target Vdd will be brought up long after the controller
is powered up, so there is no danger of SCR latchup.  Even if you figure
only 500mV drop accross the protection diode and a Vdd of 6V, that's only
250uA thru the diode.  The other direction is the worse case.  With a target
Vdd of 2V there will be 1.25mA thru the protection diodes of the target PIC.


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