STM32F429I-DISC1 board external power supply

[M. Jeong]

Posted on March 07, 2017 at 06:32

I'm planning to power the board up via external power supply. After looking at its schematic diagram, I found that one can supply power through 5V pin or 3V pin on the headers. But I wonder if you could have problem, when you would connect this board to 5V external power supply and PC also. 

You can download the schematic diagram here

http://www.st.com/en/evaluation-tools/32f429idiscovery.html

From my understanding it is just fine, since you are having two 5V power supplies. But I'm not confident and afraid of breaking my board. It would be appreciated when you would give me answer.

[Imen.D]

Posted on March 08, 2017 at 16:05

Hi,

The STM32F429 Discovery board offers the board power supply through the USB bus or from an external 3 V or 5 V supply voltage.

You can find more details and clarification on this 

http://www.st.com/content/ccc/resource/technical/document/user_manual/6b/25/05/23/a9/45/4d/6a/DM00093903.pdf/files/DM00093903.pdf/jcr:content/translations/en.DM00093903.pdf

, in 'Power supply and power selection' section.

I hope that this brings some help to you.

Imen

[M. Jeong]

Posted on March 08, 2017 at 16:12

Hi Imen,

thank you for the answer. The document UM1670 does say that you could choose 3V pins or 5V pins for power supply. But it doesn't say what happens when you provide power through USB, 3V pins and 5V pins at the same time. I guess it would not be problem to have multiple power sources, just like you could have many batteries in parallel. But I wanted to make sure if it is the case.

thanks,

[Tesla DeLorean]

Posted on March 08, 2017 at 16:42

Why not just provide 5V via the USB connector (like a charger, or juice box battery) and let the regulators on board do there job, instead of replicating multiple supplies?

>>

But I'm not confident and afraid of breaking my board.

Will the fat crazy idiot punish you?

[M. Jeong]

Posted on March 08, 2017 at 16:47

okay.. I'm just curious about the result and wonder if my understanding of the schematics is correct. I asked this question here, because the manufacturer didn't mention it specifically in their document.