ESD protection on JTAG and SWD

[dhs]

I am reading the  "Getting started with STM32U5 MCU" guie, which mentions that JTAG/SWD lines should have a 47-Ohms resistor and a 6.1V diode for ESD protection,.

I am using s STLINK-V3SET to program a custom board. STLINK already includes these componentes for ESD protection.

When design my custom PCB, I should follow the guidelines in "Getting started with STM32U5 MCU", and add additional diodes and resistor? Or it is not necessary because such components are already present on STLINK?

I will connect the STLINK and the custom PCB using a STDC14 connector.

[TDK · Accepted solution]

If you want ESD protection on the programming pins when the debugger is not attached, you'll need those components on the board.

Having them on the board, closer to the STM32 chip, will protect the chip better than if they're far away from the STM32 on the programmer.

[dhs]

Hi TDK,

• Is the STDV14 suitable for solving the production programming issue for this low-volume project of around 200 units?

• Since these lines are solely dedicated to MCU programming and do not interface with external systems, and considering that the enclosure is constructed from aluminum and is grounded, it appears that ESD protection components might not be necessary. Could you confirm if my understanding is correct?

Regards, 

Daniel

[TDK]

Do you have someone that can connect a device, hit program, then disconnect it and do that 200 times? If so, that's not an issue. It will take some time, but creating another automated solution will also take some time. I'd just use the normal programming method.

The second question is really more up to you and your project requirements. I wouldn't add any ESD protection unless I had to. The chip is not particular sensitive to ESD. Ensure whomever is programming wears an ESD wrist strap if you are worried.