dspic33 minimum connections/setup....

Started by slotbot, August 21, 2010, 08:56:29 PM

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slotbot

Hello

i am trying to solder TQFP package dspic33's however i am having a bit of trouble. I was just wondering  if anyone else has done this and can verify what the minimum connections should be.

I have attempted about 5 chips and 4 seem to suffer the exact same fate where they work for about 2 or 3 reads, then my pickit 2 complains about not being able to establish proper VDD then eventually when you connect the ICSP one of the lights blinks which i think means short circuit. (im assuming its never working properly, but at first isnt tooo damaged, then starts to melt, then melts all the way, although it doesn't smell like burning so who knows)

very possibly the soldering isnt good enough but it seems weird to have the exact same thing happen over and over.

Right now i have all the VDDs and VSS connected to each other, AVSS and AVDD connected, Im using PGEC1/PGED1. I also have a 4.7 uF tantalum from VCAP/VDDcore to ground and a 10K pullup on MCLR' . Also a .1uf cap between each VDD and VSS. I power the device from the ICSP when programming. according to the data sheet this should be enough? Is there something critical i am missing?

any tips appreciated.




slotbot

finally got this to work after another round of samples  :)