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TPS25751: Can this configuration be done?

Ryu Yamashita
Genius 3705 points
Part Number: TPS25751

Tool/software:

Hi team,

Can the following configurations be set in EEPROM?

  • The set has two power inputs: DC IN and USB-C.
  • When DC IN input is present, USB-C functions as a 5V/3A source (does not sink).
  • When there is no DC IN input, USB-C functions as a 20V/3A sink (not a source).
  • When sinking, the USB-C will not accept power from sources less than 20V/3A (power path remains closed)

Best Regards,
Ryu.

  • 0
    TI__Mastermind 30392 points

    Hi Ryu, 

    Thank you for reaching out!

    Do you have a block diagram of the different use-cases? 

    Best Regards, 

    Aya Khedr

  • 0 in reply to Aya Khedr
    Genius 3705 points

    Hi Aya,

    Thanks for the reply.
    The block diagram is as follows
    Colored paths indicate active, gray paths indicate inactive.
    The upper type of the diagram is when there is power from the DC jack and the USB-C performs 5V/3A source operation.
    The lower side of the diagram is when the DC jack is not powered and the USB-C performs a 20V/3A sink operation.
    It will standby in basic sink mode and switch to source operation when power is supplied from the DC jack.
    Roll-swapping is not performed during operation.

    Best Regards,
    Ryu.

  • 0 in reply to Ryu Yamashita
    TI__Mastermind 37855 points

    Hi Ryu,

    Do you have an EC or I2C host in the system? By it's own, the TPS25751 is not capable of setting it's power roles based off of the presence of a DC Jack. An EC would need to monitor the connection status and program the PD controller in the sink only or source only configuration.

    Thanks and Regards,

    Chris

  • 0 in reply to Christopher Lim1
    Genius 3705 points

    Hi Chris,

    We wanted to achieve this by pre-writing to EEPROM and then writing to the device at startup.
    Does this mean that this is not feasible?
    I guess this means that a host is still required.

    Best Regards,
    Ryu.

  • +1 in reply to Ryu Yamashita
    TI__Mastermind 37855 points

    Hi Ryu,

    Correct, this is not possible without a host. The TPS25751 + pre-written EEPROM does not have the capability to change the power role configuration automatically in the way you are describing.

    Specifically, knowing when a certain state has been entered and modifying the power roles is not possible with the TPS25751 alone.

    Thanks and Regards,

    Chris