Low Voltage PIC

[Eugeneo]

I have a project using a 16F819 running at 5 volts, it will not run at 3.3 even if the fuses are set right. The 16LF819 runs at 5 - 3.3 down to 2 volts provided the fuses are set right. The strange thing is almost all my 12F629s and 12F675s run fine from 5 all the down to 1.8 volts. All of which are running at the max internal osc. speed. (4 or 8)

so..

I have a ICD-S and a Machx. Using the Machx is it possible to change the Brown out fuse on the ICD-S so it will function at 3.3 volts?

I can use the Machx at 3.3v, but it does not double as an ICD Debugger. I can use the ICD-S but it does not function at 3.3v(ICD-U).

Does anybody have any idea what I am tring to say?

[John Leung]

I have got similar experience with 16F88. From data sheet, it will only work down to 4.5V but I've found it works down to 3V with internal osc running at 4MHz. I did post a question to Microchip about this. The answer was that, every 16LF88 tested for Vdd down to 3.0V, whereas there is no guranttee that every 16F88 will work at low voltage less than the official Vdd value 4.5V.

John