Hello!
I've been working with several STM32 parts since 10 years. I'm working for a company so due to confidentiality I can't share the schematic of the custom PCB, sorry.
On the first batches of a new product, using a STM32H743BI, it appears that some of them (around 2%) have an issue in common : these STM have an internal short-circuit on GND-3V3. That's not a real short circuit, it has a resistance, that can vary from 5ohm to 20ohm. So the package become really hot when being powered by 3V3, and is not working at all.
This short-circuit seems to happen from the factory assembly, or from the first power on, I don't know for the moment. But the other working PCB are shipped to 1000+ customers since several months and no issue has been reported.
So it seems that the STM has a quality problem after (or before) the SMD assembly. We used several STM tray batches # and the issue happen with all.
Also, the STM32H743BI is only connected to 3V3 levels. Changing the part on a board and the issue is fixed.
The most strange is that I never had that kind issue with STM before!
Do you know if there is that kind of quality issue with this H7 technology?
Have a nice day!
Jean
