What is the max. value of Vref (ADC reference voltage)? Acc. to the datasheet, The low is Vss - 0.3V. That is clear. But what is the high value?
The datasheet for PIC18F4520 says (param. A21, pg 358), VREFH (reference voltage high) min. = Vss, VREFH max. = VREFH. I dont understand what that last figure (max.=VREFH) means.
The datasheet for PIC16F877A says: (param A21, Vref+): AVDD + 0.3V. Tho Im not sure what AVDD is, I guess that's the same as VDD + 0.3V.
Im wondering because the usual 5V supply to power the chip comes from an LM7805, which is in my case is about 4.95 V, while Vref is exactly 5V. Is this a problem?
Thanks,
vkj