TPS25751: TPS25751 no role when connected to laptop

Stefano Nobili

Part Number: TPS25751
Other Parts Discussed in Thread: TPS25750

Tool/software:

Hi TI,

I'm working with a custom board with a TPS25751 and I have a problem to setup the device correctly. When I connect my custom board with a notebook via the type-c port of the notebook the tps25751 fails to contract a power role, but I want that the TPS becomes sink and the notebook becomes the source.
My scenarios are the following:

Connect my board with a smartphone, the tps is the source and the smartphone is the sink
Connect to laptop with usb-a cable, the tps is the sink and the notebook is the source
Connect to laptop with usb-c cable, the tps is the sink and the notebook is the source

The first two scenrios are working, but the last case doesn't work.
Can I send a 4cc command to adjust this case or I can configure the TPS to work properly in all the cases?

I attached a link to download my configuration.
Thank you in advance!

drive.google.com/.../view

2 months ago

0 Chris Sterzik 2 months ago

TI__Guru 63171 points

Hello,

You could change the PD to initiate the swap to sink but this will most likely impact the first scenario.

The 4CC command would be better once the system understands the configuration. 'SWSk' - PD PR_Swap to Sink

https://www.ti.com/lit/ug/slvucr8a/slvucr8a.pdf#page=59

Regards,
Chris

0 Stefano Nobili 2 months ago in reply to Chris Sterzik

Prodigy 40 points

I tried both solutions but it doesn't work. Even if I set the TPS with preferred role Sink the negotiation fail. At the moment I'm not able to configure the TPS in order that the TPS works as sink and the notebook works as source.
With TPS25750 when I set the preferred role Sink the system worked properly.

0 Chris Sterzik 2 months ago in reply to Stefano Nobili

TI__Guru 63171 points

Hello,

Stefano Nobili said:
With TPS25750 when I set the preferred role Sink the system worked properly.

That is not expected. Can you comment on the version of the GUI you are using and possible provide the configuration file (json) of the TPS25750? Have you attempted to load the TPS25750 configuration onto the TPS25751 to see if the behavior follows the silicon or the configuration?

Regards,

Chris

0 Stefano Nobili 2 months ago in reply to Chris Sterzik

Prodigy 40 points

Maybe I wasn't clear in my last post. The TPS25750 works properly when connected to the notebook via USB-C, but it dosen't charge the smartphone.
This is the configuration
https://drive.google.com/file/d/1dcnQ1e6ItFpG649q0nWd7LJF5WbZ1Y36/view?usp=drive_link
I will try to load the TPS25750 configuration onto the TPS25751 and I let you know.

Best regards,

Stefano

0 Chris Sterzik 2 months ago in reply to Stefano Nobili

TI__Guru 63171 points

Hello,

Stefano Nobili said:
I will try to load the TPS25750 configuration onto the TPS25751 and I let you know.

Thank you. I will work on the difference in performance between the TPS25751 and TPS25750.

Regards,
Chris

0 Stefano Nobili 2 months ago in reply to Chris Sterzik

Prodigy 40 points

I found how I can use the TPS25751 with both situation, smartphone and laptop. The configuration is the following:
https://drive.google.com/file/d/12PltjuDiWL1Ks-ImEjhiBvcAqE_-ifQl/view?usp=sharing
I have to switch manually between source and sink but it works. Now I'll try different config to try to automate the process.
Thanks

Stefano

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TPS25751: TPS25751 no role when connected to laptop