I do fairly simple stuff using PIC Basic (not “Pro”) mostly using chips to drive switches and as timers. I have had a couple of chips fail (12f629) which has not been a big deal but I wonder about the failures.
Since I expect to be asked, the failures are in a circuit powered by a dc supply that runs parallel to 120v ac lines, so I have a 100uf cap at the input, and a 78L05 regulator, a .1 cap on the 5v side. The out put is a led flasher protected by a 1K resistor. A 16F84A chip uses the same supply a bit south with no problems. All other pins are inputs, internally pulled up except pin 3, pulled up with a 20K resistor. I make my own circuit boards with Press-n-Peel Blue.
I have concluded, with no evidence at all, that the older simpler chip would be more robust than similar more complex chips developed more recently. Say 12f675 or 12f683 or others I don’t know about? (Is there a catalog available to guide chip selection?)
Are any particular chips more rugged than others. Does any one know? Does anyone care. Afterall, all chips that I have used have continued to perform with the one exception so I have no complaint. Since my production runs have never been more than 3, cost is not a big factoe for me.
Comments welcome.
