• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 33 subscribers
  • Views 1220 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

USB Power Delivery IC for Device (USB Slave)

Michael Koelbl
Intellectual 290 points
Other Parts Discussed in Thread: TPS25741, TPS65981

We are developing a USB-C Host and a USB-C Device electronic which shall use USB PD to provide 24V/3A. We're using TI TPS25741 as USB PD source controller. It is configured to be able to deliver 24V/3A after PD communication with the device. Now we need a "companion" chip for the USB device. In best case it should be a standalone ic which shows the USB host that it wants 24V/3A. We would then have a 24V power supply for our device electronic which starts operation after 24V is applied by the USB host (TPS25741). 

  • 0
    TI__Mastermind 36756 points
    Hi Michael,

    We do not have an upstream PD controller that can do 24V since this is outside of the PD spec and is a non-compliant voltage. I would recommend using the TPS65981 to negotiate 20V/3A as a sink and then boosting that 20V up to 24V on the sink side.

    Thank you,
    Eric
  • 0 in reply to Eric Beljaars
    Intellectual 290 points

    Hello Eric,

    sorry, we have 20V not 24V.

    I had a look at TPS65981 but I think a simplier device is enough for me.  I don't need power path switching. I will have a power supply with 20V input and an undervoltage lockout so it is idle as long the VBUS voltage is below 20V. Therefore I can connect the power supply directly to the USB-connector's VBUS. All I need is a controller for the CC line which tells the PD host to apply 20V on VBUS. I have attached a block diagram.USB-PD.pdf

    Thank you,

    Michael

  • 0 in reply to Michael Koelbl
    TI__Mastermind 36756 points
    Hi Michael,

    To be PD Compliant, it is recommended to have a Power Path switch to isolate the system side capacitance. Per the PD spec, VBUS is only allowed to have 10uF of capacitance on it. The TPS65981 can be configured to be a sink only device that can operate solely off of VBUS as the only power supply.

    Thank you,
    Eric