Quote Originally Posted by Dave View Post
Chris, what voltage level is the supporting electronics going to run at? If it is 5 volts then I would enable the internal VCORE regulator and run the processor at 5 volts.
Absolute maximum voltage for the PIC18F87J50 is 4.0V (recommended is 3.6v) - Section 28.0 of the data sheet.

NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.