Hello!
I have a design with the ISOW7842DWE isolated 3v3 chip. We have had an issue with the voltage of the ISO side dropping to 0.3 or around 2 V. The resistance between iso_3v3 and iso_GND are on some chips around 2-3 ohms and on some chips 22 ohms.
We have removed one chip and tested directly on it, which also showed 22 ohms, which means it is the chip and not the PCB which is at fault.
Is this something you have seen with this circuit before?
The PCBs have been lying in a ESD safe bag for a few years and the previous PCBs we have used have not showed this issue before. Roughly 2/3 of our remaining PCBs are still functioning it seems.
Could it be some kind of aging effect? Should we be worried that the PCBs we have sold could suffer the same issue? We have, however, not yet heard any complaints from our customers.
With one PCB I tried supplying 3v3 externally to the ISO 3v3 on one PCB and the chip seemed to magically spring back to life. Don't know what happened and I haven't managed to replicate it.
