TPS25751: PDO configuration without EEPROM

Masashi Mineda

Part Number: TPS25751

Tool/software:

Dear Sirs and Madams,

We are considering a configuration for the TPS25751 that does not use an external EEPROM, and we understand that various registers will be set using 4CC commands from an external EC.

We confirmed for the TPS25751 TRM, and we would like to know about the PDO settings.

As an example, for the source PDO settings, I think that we would lile to set "TX Source PDO x" in Table 3-17 of TRM, but I don't know how to determine the value of this register.

Among them, the initial value of Tx Source PDO1 is "260C844Ch", which I think means 5V, but if I don't understand this setting value, I won't be able to set the other PDOx, so could you please tell us?

Regards,

Masashi

5 months ago

+1 Christopher Lim1 5 months ago

TI__Mastermind 37855 points

Hi Masashi,

The TPS25751 Tx Source PDOs are stored in the exact format defined in the USB-C PD spec. I would recommend downloading a copy of the "USB Power Delivery" spec from here: https://www.usb.org/documents

This is the section you will need for formatting of the PDOs

The different types of PDOs are formatted differently (Fixed, variable, APDO), and here is a screenshot of the formatting of a fixed PDO.

Keep in mind that the first PDO is always a 5-V PDO, and only it contains the extra bit information from bits 29:23. The other fixed PDOs (PDO2+) only need the Supply type(B31:30), Peak current (21:20), voltage (19:10), and max current (9:0).

Thanks and Regards,

Chris

0 Masashi Mineda 5 months ago in reply to Christopher Lim1

Expert 1175 points

Hello Chris,

Thank you for your answer.

I understood this issue.

Regards,

Masashi

0 Christopher Lim1 5 months ago in reply to Masashi Mineda

TI__Mastermind 37855 points

Hi Masashi,

Closing this thread now.

Thanks and Regards,

Chris

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TPS25751: PDO configuration without EEPROM