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TUSB320: Some questions about TUSB320

ju sheng
Prodigy 60 points
Part Number: TUSB320

Tool/software:

Hi Team，

I have a few questions to confirm,
1. TUSB320 defaults to UFP mode. If VBUS is not connected by default, can TUSB320 work normally in unattached mode? And can the DFP end function normally?
2. After 10 minutes in UFP mode, if TUSB320 is dynamically switched to DFP through i2c, can the other end automatically switch to UFP?
3. Is there any problem with the following design diagram?

Best,

Ju.sheng

  • 0
    TI__Mastermind 39810 points

    Hi,

    1) The default startup start is going to be what port is set to. In this schematic it seems that the port is pulled up to it will default to DFP mode. 

    2) If you are looking to swap the roles of the ports without unplugging the connecting cable, we do not support this function with a CC controller. This will need to be done with a PD controller.

    3) From my understanding its best if you use a PD controller rather than a CC controller here. 

  • 0 in reply to Vishesh Pithadiya
    Prodigy 60 points

    Hi Vishesh,

    >>>1

    The role switching logic we designed is as follows:,
    1. By default, the port pin is pulled down, and then power on the VDD pin and enable EN pin. TUSB320 is in UFP mode now.
    2. After ten minutes, power off the VDD pin and turn off the EN pin, then the port pin is pulled up.
    3. Finally, power on the VDD pin and enable the EN pin, TUSB320 is in DFP mode now.
    Is role switching supported in this process?
    >>>2
    For the above process, If VBUS is not connected by default, can TUSB320 always work normally in unattached mode?
  • 0 in reply to ju sheng
    TI__Mastermind 39810 points

    Hi,

    For the sequence to work, you may need to physically unplug and replug the USB-C cable before role swapping. 

    I'm not sure what you mean. If Vbus is disconnected and the cable remains plugged in; this will result in a failed attach and will not be in the unattached state. This is because the CC pins will have the PUP and PDOWN resistors seen to begin the attach process and Vbus delivery is one of the last steps in the attach process. 

    Not having Vbus available will mean that the attach process will begin and fail. Meaning that the TUSB320 will not be in the unattached state. 

  • 0 in reply to Vishesh Pithadiya
    Prodigy 60 points

    Hi Vishesh,

    Thank you for your reply, it has been very helpful to me~

    Best,

    Ju.sheng

  • 0 in reply to ju sheng
    TI__Mastermind 39810 points

    Ho Problem!, let me know if you have more questions.

  • 0 in reply to Vishesh Pithadiya
    TI__Mastermind 39810 points

    closing due to inactivity