Question
Can the ADC inputs exceed the reference voltage or go below ground?
Answer
The ADC inputs should not exceed the reference voltage or go below ground by
more than 0.3V as this may result in the ADC being damaged. If this is a common
condition then Schottky diodes should be used to protect the inputs and limit
them to
Transient currents of up to 100 mA do not cause SCR latch-up on the REF pin.