2020-04-01 08:02 AM
Dear Community,
I'm facing a bad issue on a recent board I designed.
The board is supplyed by 12/24V battery and drive some magnetic valves.
Unfortunately during precompliance surge test, based on EN 61000-4-5, the VNQ5050K got destroyed and the microcontroller too. I guess the disturbance overtake the protection, enter and destroyed the mosfet and pass to the microcontroller lines.
Attached the part of the schematic affected by the issue.
The power supply and the surge was injected on the PWR line. The mosfet array is connected to the PWR line and modulates the high-side of any output. The current is closed through a low side moset.
What is also strange is that the surge affected the VNQ505K, but not the VND5050.
Any suggestion is wellcome,
Thank you in advance,
Luca
Thank you very much