3.2 Making the Most Out of ADCC Channels

Configure the appropriate ADC positive and negative channels using the ADPCH and ADNCH registers for the differential ADC measurement. The input sources for the positive and negative channels could be from external sensor/signal circuitry or the outputs of microcontroller peripherals such as Temperature indicator, Fixed Voltage Reference (FVR), Operational Amplifier (OPA), Digital-to-Analog Converter (DAC).

In the case of single-ended ADC measurement, the ADPCH register selects the positive input. The ADC hardware ignores any negative input selections chosen by ADNCH.

It is also possible to select one of the ADC channels (positive or negative) from an external pin and another channel from the internal peripheral output in Differential Measurement mode.