We use two ADUM1402 to connect 74hc244 and then communicate separately with two groups of 74HC165D chips. The QH(PIN-9) of 74HC165D is connect directely to the AUDM pins. (Attach are the schematics for reference)
The question is that the ADUM1402 chips are broken in some board, even both were damaged sometimes, the chips are hot when do not work. We have to change another chip, then it will work normally again.
The power supply converter used TI-TPS5430DDAR.
Any suggestions would be much appreciated.