Hi, Rob

Consider all inputs are clamped to Vcc + .6 v ... ( take care: clamps diodes are very Weeeeeeak ! )

so, the best is not to have more than Vcc ... or use strong external clamp diodes ( 1 N4148 i.e )

but analog inputs can rise to Vref + 2v ... not forgetting Vcc+.6v is an absolute maximum ...

Alain