Hi Expert,
May I have your support to see this case and we also sent the FA to check.
But we need your idea to know more detail and comment as below
When the off-state PSU plug-in to the 12Vbus ( 1 PSU ready and 12.2V is on voltage Bus), the C pin will see a 20.08V voltage spike ,duration ~1-200ns.
Since the spike is over Pin C 18V IC rated voltage. Is it the cause to breakdown the IC Pin C? Please comment on this finding.
Besides, can you give me some other cases or examples which can breakdown the IC? I will try to simulate or evaluate.
They added a RC, 10ohm and 1nF on Pin C, 10ohm R24 is connected between 12V and Pin C.
Do you see any risk from this design ?
Eddie