32.2.4 ADC Operation During Sleep
The ADC module can operate during Sleep. This requires the ADC clock
source to be set to the FRC option. When the FRC oscillator source is selected, the ADC
waits one additional instruction before starting the conversion. This allows the SLEEP
instruction to be executed, which can reduce
system noise during the conversion. If the ADC interrupt is enabled, the device will wake
up from Sleep when the conversion completes. If the ADC interrupt is disabled, the ADC
module is turned off after the conversion completes, although the ADON bit remains set.