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TUSB9261: TUSB9261 VBUS design requirment

Hailey Chen
Intellectual 2210 points
Part Number: TUSB9261

Hi, team: 

    Could you help check the USB_VBUS limited value?

    I noticed in Q version it describes as follow:

   

   Does it means the USB_VBUS VIH limited is 0.4V ?（The signal USB_VBUS must be connected to VBUS USB_VBUS 50 I through a 90.9 kΩ ±1% resistor, and to signal ground through a 10 kΩ ±1% resistor.）

   And I hope to know what will happen if USB_VBUS is lower than the VIH limited？

   Hope to get your reply, thanks.

  

    

  • 0
    TI__Mastermind 22765 points

    Hi Hailey,

    The same logic for designing around USB_VBUS applies to both versions of the TUSB9261.

    This pin uses a 1.2V I/O cell, so the voltage divider that is recommended will lower the voltage of VBUS when VBUS is between 4 and 10 volts down to an acceptable level for the pin and prevent damage. Since this pin has a 1.2V max, it will naturally be less than Vih, and the detect threshold is about when VBus is 4V.

    Please let me know if you have any other questions.

    Thanks,

    Ryan 

  • 0
    TI__Intellectual 2210 points

    Hi，Ryan：

    Thanks for your reply.

    what will happen if the vbus lower than 4v？

  • 0 in reply to Hailey Chen
    TI__Mastermind 22765 points

    Hi Hailey,

    If VBus is lower than 4V, then the device will not detect a connection, and will assume no USB device is connected. If your VBUS is less than 4V minimum, then you may modify the values of the voltage divider to better accommodate your voltage levels.

    Please let me know if you have any other questions.

    Thanks,

    Ryan.