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ugurozkan52
ugurozkan52
Associate
July 6, 2026
Solved

How should i connect SWD Pins as safety for EMC/EMI?

  • July 6, 2026
  • 1 reply
  • 53 views

Hi Dear,

I connected as picture my SWD pins. What is best solution for SWD Pins? Sould i capasitor, TVS or safety component? Is there any guide for STM32?

 

 
 

 

 

Best answer by Ozone

Normally you don’t need EMI protection for the debug interface, the SWD/JTAG lines have system voltage level, and are short.
The debug adapter works at the same voltage level (3.3V), so interferences are very unlikely.

If you have a very EMI-prone environment like motor control or another kind of driver for large inductivities, I would recommend an isolated debug interface.

As far as I understand it (I am not a hardware guy), these isolated debug adapters are intended to protect the debug adapter and the host, not the target.
 

1 reply

Ozone
OzoneBest answer
Principal
July 6, 2026

Normally you don’t need EMI protection for the debug interface, the SWD/JTAG lines have system voltage level, and are short.
The debug adapter works at the same voltage level (3.3V), so interferences are very unlikely.

If you have a very EMI-prone environment like motor control or another kind of driver for large inductivities, I would recommend an isolated debug interface.

As far as I understand it (I am not a hardware guy), these isolated debug adapters are intended to protect the debug adapter and the host, not the target.
 

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