TPS25750: Disable Source role to save power question

Luca Marongiu

Part Number: TPS25750
Other Parts Discussed in Thread: TPS25751

Hello Everyone,

I am using the TPS25750 as dual (sink and source) roles, and I want to disable the source capability to save power (like a power saving mode).

I do not understand from the User Guide (https://www.ti.com/lit/ug/slvuc05a/slvuc05a.pdf?ts=1709200793179&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS25750) how to do it...

I thought that reducing the number of Source PDOs to 0 in register 0x32 (first 3 bits of the first byte) and sending the "SSrC" command should work, but it didn't. Then I tried also to put also the maximum current to 0 (first 10 bits of the PDO's bytes), my phone (attached to the TPS via USB-C) starts activating/deactivating the battery charge constantly.

What am I doing wrong?

Thank you in advance

over 1 year ago

0 Luca Marongiu over 1 year ago

Prodigy 40 points

This is my TPS configuration with the Application GUI:

{"questionnaire":{"version":"7.0.4.7","answers":[0,0,0,0,1,3,1,null,1,null,0,8.4,1,0.04,0.4],"options":{},"configID":"0000","vendorID":"0000"}}

0 Aya Khedr over 1 year ago in reply to Luca Marongiu

TI__Mastermind 29992 points

Hi Luca,

Thank you for reaching out!

Your thought process is correct in terms of reducing the number of source PDOs to 0. Although, I did notice that the preferred power role in question #4 is set to "Power Source" which is most likely why the port is still attempting to source when attached to a sinking device (phone). You could try changing this to "power sink" for now.

On the other hand, I do want to highlight our follow-on device, the TPS25751, recommended for all new designs. Please see the following FAQ: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1346998/faq-tps25751-migrating-from-the-tps25750-to-the-tps25751

Using the TPS25751, you would be able to change the TypeC State Machine to "Sink-only" (Port Configuration register 0x28) when you want to disable the source capability to save power.

Please let me know if you have additional questions/concerns.

Best Regards,

Aya Khedr

+1 Luca Marongiu over 1 year ago in reply to Aya Khedr

Prodigy 40 points

Hi Aya thank you for the response,

There was a small bug in our implementation, by changing the maximum sourcing current of the PDOs to 0 mA it works!

The only thing is that it starts one time the phone charging animation and then stops, but this behavior can be accepted by us.

0 Aya Khedr over 1 year ago in reply to Luca Marongiu

TI__Mastermind 29992 points

Hi Luca,

I am glad to hear that its working!

Feel free to open a new thread for further questions.

Best Regards,

Aya Khedr

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TPS25750: Disable Source role to save power question