Mark Rages wrote: > On 1/19/07, Rich wrote: > >>Hi guys: >>I stupidly put 5 volts to a 3.3 volt part. I missed it in the checking and the PCB is fabbed. I thought of lifting the pin (can't cut the trace because it is an internal layer) and knocking down the voltage with a zener glue-on. I hope the zener impedance will be low enough. The part is an EEPROM. Has anyone had any experience with this type of fix? I will get new boards for production but I don't want to spring for another 300 bucks for a test board. I confess to stupid things from time to time. > > > It will probably work, but you'll need to add a 50K resistor to ground > to make a bit of current go through the zener. > > Does the EEPROM have chip enable inputs that are fixed at 3.3V? You > could leave Vcc disconnected and power through the protection diodes > on those inputs. Not a long term solution, but it might get you by > until your next board rev. If you can lift the pin to put in a zener, why not just use a wire jumper to 3.3V? Wire wrap wire works nicely for this. R -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist