This is our USB interface to a PIC32MX microcontroller. Left side is powered by USB, right side with 5 V. We use this design since some years and never had problems with it. But the last few weeks, we encounter that some ADuMs get very hot and don't work or even burn and break their package. Any idea, whether this is a bad batch or something is out of spec? Photo of PCB assembly with a broken IC below ...