Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 33 subscribers
  • Views 1430 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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 Hub with upstream and downstream on the same port.

Yiangos Yiangou
Prodigy 20 points
Other Parts Discussed in Thread: TS3USB221

We are designing a device, which has 2 USB C ports. Those USB C ports are in USB 2.0 compatibility mode and are not PD capable.
Our requirements are that the the device can be plugged to a host from any of the 2 USB ports. The second USB port can then be used as downstream for a low power device (such as a mouse).

There is also a MCU on the device that is also connected with USB. The device is also bus powered from the host.

Is there any proposed solution for a usb hub that can do the above?

  • 0
    TI__Guru**** 157496 points

    Hi,

    Not with a single hub solution. Below is a proposed block diagram to achieve this using the TS3USB221 MUX. I did not include a VBUS MUX in the block diagram, but you need a MUX that can switch the VBUS between the two Type-C ports (High-Low-High).

    Thanks

    David

  • 0 in reply to David (ASIC) Liu
    Prodigy 20 points

    Thank you for the prompt reply David.

    My idea was to create add power diodes after the VBUS of each USB C port and connect them together for a common 5V rail, use that 5V rail to power my MCU and other logic. Use the voltage before the diode to detect which USB C is upstream.

    To then get 5V to the VBUS of the downstream port, use a switch which "bypasses" the diode of that port.

    Does this seem like a good solution?

    Any other Vbus muxing schemes which you might suggest?

    Cheers,

    Yiangos

  • 0 in reply to Yiangos Yiangou
    TI__Guru** 123980 points

    you may need to add vbus switch to reset Vbus after MUX change USB data, USB communicaton could be stuck with Vbus always on