My STM32 device is overheating and has malfunctioned

Wadeva · ‎2024-09-23

Hello,

We’ve designed a device that uses an STM32 microcontroller to manage various features such as I2C, UART, ADC, IWDG, DMA, Flash memory handling etc. After running smoothly for a month, the device began malfunctioning, drawing 220 mA of current and heating up noticeably. I’m trying to determine the root cause of this issue. Could you provide insights into the possible reasons for this behavior?

Thank you.

Andrew Neil · ‎2024-09-25

@Wadeva wrote:
Now, my challenge is different.

Please start a new thread for a new question.

Provide a link here, so that people can find it.

You can provide a link in the new thread back to here for reference.

You're going to need to give more details about this "unprotected" pin - show schematic, etc.

LCE · ‎2024-09-25

> unprotected pin that is connected to the chassis ground of the device

>> Since the design is already completed and the PCBs have been manufactured,
>> it’s unlikely that we can make changes to the layout at this stage.

Bad idea with that BIG design error! I wonder how that one got through any design checks.

You could still test the device's ESD behavior.
If the chassis is perfectly grounded and chassis potential is the same as STM32's local GND, it might still work...

But as it is already having problems without ESD... or have you solved the heat problem by changing GPIO mode of that pin?

AScha.3 · ‎2024-09-25

On existing boards: your only chance is a simple but good, low impedance connection to board/cpu GND.

Maybe a solder joint to ground plane , direct at the point, where the "signal line" comes to the board.

If you feel a post has answered your question, please click "Accept as Solution".

White_Fox · ‎2024-09-25

@Wadeva wrote:
Hello everyone, after reviewing our design, I discovered an unprotected pin that is connected to the chassis ground of the device. I’ll need to check if there are any other similar pins. It must be the problem.

In this case, you better provide more information. In special the (important parts of the) schematic. A new thread is a good idea - with linking here to it.