Can the ADC measure 5 V if the VDD is 3.3 V?

Probably not, as there are several problems with attempting to convert a 5 V signal if the Vdd is 3.3 V.

  • Check the pin diagram for the PIC® device to see if the input pin being used is 5 V tolerant.

Note: ADC pins including reference voltage pins are usually not 5 V tolerant.

  • Even if the input pin is 5 V tolerant, the conversion may not be successful. Check the "Electrical Specifications" section of the device datasheet to see the max values for the reference voltage and ADC inputs.
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