I have a design that uses the TLC372 comparator. This is a legacy design for my company that I inherited that has about 15 years of pedigree. I'll admit there are conditions where the input voltage is greater than the supply voltage of the comparator, but based on my analysis we have enough impedance to satisfy the requirement of limiting the input currents to 5 mA.
We recently had a new application of our system and had two separate failures with very low hours. In both instances the "B" side of the comparator is exhibiting a permanent "LOW" output. What threats could cause this failure mode? Are we damaging the output section or the input section? Would the failure mode tell us if the damage is on the inverting or non-inverting input?