ARM Debug probe with power to target capability

Gaston · ‎2026-02-10

I have been using PE micro Multilink FX for several years, but its Linux support is terrible. Is there a ST (or another) alternative with this functionality compatible with stm32CubeIDE? I just need to supply power (up to 100 mA at 3.3V) to my board for debugging. I don't need high tracing performance or anything like that.

Thanks in advance,
Gaston

TDK · ‎2026-02-10

Thanks for explaining that.

No, this isn't available on any ST-Link programmers. Pin 1 is always an input.

You could either modify the programmer hardware to short pin 1 to 3.3V, or you could use power on the 20-pin connector. But the functionality you want is not available on an ST programmers without hardware modification.

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Andrew Neil · ‎2026-02-10

Is that just to supply power, or do you also want to monitor the supplied power?

For the latter, see STLINK-V3PWR

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Gaston · ‎2026-02-10

Is that just to supply power, or do you also want to monitor the supplied power?

I just to supply power to the target

For the latter, see STLINK-V3PWR

No. I need supply power 3.3V through 10-pin connector along SWDIO, SWCLK and RESET signals.
STLINK-V3PWR supply power through a separate connector instead.

TDK · ‎2026-02-10

> Is there a ST (or another) alternative with this functionality compatible with stm32CubeIDE? I just need to supply power (up to 100 mA at 3.3V) to my board for debugging

Power is not supplied in the standard 10-pin ARM debug header. All ST programmers adhere to the standard and do not supply power on a 10-pin connector.

https://documentation-service.arm.com/static/5fce6c49e167456a35b36af1

It doesn't look like the 10-pin header on the PE micro Multilink FX is any different. What pinout are you using that you want to duplicate functionality?

The st-link v2 has a 20-pin connector with 3.3V power supplied on pin 19. That's the closest you'll get.

ST-LINK/V2 | Tool - STMicroelectronics

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Gaston · ‎2026-02-10

That's right. PEmicro Multilink FX is a special case. I use this:

I connect the port G with my target MCU (standard ribbon 10-pin cable or Tag-connect) and voilà!
The target is 3.3V powered successfully by the debug probe.

Also PEmicro is very clear about the 'to power target MCU' capability

But ST not...
After reviewing several user manuals (STLINK/V2/V3/V3MINIE, etc.), I still don't understand whether this functionality is possible or not. I'm also not sure whether this option can be enabled from the stm32cubeIDE. Can anyone clarify this?

Chris21 · ‎2026-02-10

Segger J-Link probes are very good and can supply 5 volts.

It appears they have an adapter for other voltages: https://www.segger.com/products/debug-probes/j-link/accessories/adapters/supply-adapter/.

https://kb.segger.com/20-pin_J-Link_Connector

"Pin 19 (5V-Target supply) of the connector can be used to supply power to the target hardware. Supply voltage is 5V, max. current is 300mA. The output current is monitored and protected against overload and short-circuit. For more information about how to enable/disable the power supply, please refer to Target power supply "

TDK · ‎2026-02-10

Thanks for explaining that.

No, this isn't available on any ST-Link programmers. Pin 1 is always an input.

You could either modify the programmer hardware to short pin 1 to 3.3V, or you could use power on the 20-pin connector. But the functionality you want is not available on an ST programmers without hardware modification.

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

Andrew Neil · ‎2026-02-11

Perhaps a better approach would be just to make an interposer/adaptor board to allow the target power to come from either the debug probe or a separate source?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Gaston · ‎2026-02-11

Great. Thanks TDK & Chris21 for the clarification! Just one thing:

It appears they have an adapter for other voltages: https://www.segger.com/products/debug-probes/j-link/accessories/adapters/supply-adapter/.

Interesting. I didn't know about this adapter.

I believe this offers the possibility of removing VCC from the target board connector (maybe to simplify the PCB layout?). This way, it ‘tricks’ the debug probe for monitoring its own voltage (pin19) instead of monitoring the target MCU voltage. With all this, it does not end up providing power to the target MCU.

Gaston

Gaston · ‎2026-02-11

Yes, it won't be difficult. This reminds me of when I used to make my own debug probes with FRDM boards
https://mcuoneclipse.com/2013/04/21/using-the-freedom-board-as-jtag-programmer/

You just need to supply power through pin1, as we have been discussing.