S32K144EVB-Q100: 5V Power Bank and MicroUSB?

[mahmoudsherrah]

I am trying to power my S32K144EVB-Q100 using a 5V power bank through the micro USB port. I do not want to use the external power supply plug on-board.

The board works fine when plugged to PC using the microUSB port. However, when I try to use a 5V power bank instead, the board doesn't power on at all.

I understand that the microUSB is input to the OpenSDA chip and the chip transfers this power to the rest of the board.

Does the OpenSDA need to detect data activity (which is not provided by the power bank) as well as power in order to work? Is there a way to bypass that?

[mahmoudsherrah · Accepted solution]

EDIT: I can confirm that soldering R70 allows me to use 5V power bank through MicroUSB port. Flashing/Debugging is not affected.

That is really unfortunate.

Do you think that soldering R70 might help?

[danielmartynek]

Hi,

Yes, that works.

Regards,

Daniel

[mahmoudsherrah]

Thanks for the follow up Daniel.

I am not very good at electronics, so do you think soldering R70 will interfere with POWER_EN signal from OpenSDA if I want to program or debug again?

[danielmartynek]

Hi Mahmoud,

It should work, I don't see any problem with that.

Regards,

Daniel

[mahmoudsherrah]

Thanks for your support!

[danielmartynek]

Hi,

I tried on my side and indeed it works only with a PC.

In the schematic, there is a power switch U11 and the MK20DX128VFM5 enables it (POWER_EN).

I don't know how it works but it seems there needs to be some communication.  

Regards,

Daniel