mds
Joined: 06 Nov 2005 Posts: 29
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ICD U64 pgc dead. Fix and why didnt they tristate? |
Posted: Thu Apr 19, 2012 5:49 pm |
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Hi All,
For quite some time most of our boards use the pgc,pgd pins for mode indication via LEDS, having used another programmer this has never been a problem.
However the U64 does not tristate and so after programming one has to remove the header so as to monitor the LEDS.
We have just had to put up with this since we switched to these programmers.
The other day one of our field U64s turned up here as faulty.
After pulling it apart I found the TC7WH125FKFCT-ND chip that drives the PGC pin to be defunct. Who knows what the field boys did to it.
After replacing said chip, the one near the LED, all was well again. It did however cause me to ask the question. Why is the U64 not utilising the tristate feature of this driver chip? In both cases the "enable"pin of these chips is connected to power rail. It would have been simple to drive this from the many "spare" PIC IO pins. A bit of a CCS oversight? Or am I missing something?
The part is available from digikey In case anyone else has "all thumbs" field techs and find a dead pgc or pgd output.
It is a little tricky to hand solder but it is doable.
Error created was: unable to ID target device. |
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