STLINK-V3MODS for custom PCB

[bramble]

Hi Community,

I'm designing a custom H755 board and had intended to implement my own USB-C with debug/programming interface using an external STLINK module. 

STLINK-V3MODS is a nice alternative way forward but I note from the user manual (UM2502) that it can only deliver up to 200 mA at 5V, whereas I need around 500 mA.

Is there an alternative debugger-progammer module that I can use, whilst also using this to deliver 5V with enough power to supply my board (power taken from USB obviously)?

I want the option to use a power-bank battery pack to power my circuit in normal operation, but the ability to program and debug via USB.

Thanks

[Andrew Neil]

It is unusual to put a debugger on a custom board.

Normally, one would just provide a debug connection.

What's the use case for putting the debugger on the board?

[bramble]

Hi @Andrew Neil , thanks for your reply - you raise a good question. Well, it's true that all I really need is the ability to flash-download and debug my board, and that was my original intention. Then I had the thought that the cost of putting an STLINK-V3MODS on the board was so low that this could be a convenient way to achieve the same, whilst saving me a USB connector and the signal conditioning needed to obtain a 5V supply from USB's VBUS.

Also to mention, my board, although being designed for a fairly specific application, is sufficiently general that I can hopefully use it as a general development board.

Thanks

[Sco]

Another point based on "STLINK-V3MODS" is to replace the LDO on the board to a 500mA one. 

[MHoll.2]

The 200mA limit is probably because the STLINK-V3MODS can consume up to 300mA, so the USB standard limit of 500mA is not exeeded. I don't think that there is any LDO or protection between the VBUS (5V) and the 5V output on Pin 22 of the module., So when You can garantee that you USB Host port can deliver at least 800mA, You should be fine using up to 500mA from the STLINK-V3MODS module.

[bramble · Accepted solution]

Many thanks @MHoll.2 and @Sco , very helpful points and advice.