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TS3USB3031: USB2 I/OV higher than supply V

Part Number: TS3USB3031
Other Parts Discussed in Thread: TS3USBA225,

Hi all,

If the chip is powered by 3V, while the USB2 I/O inputs see 3.3V, will this work okay?

Thank you,

Austin Allen

  • Hi Austin,

    What do you mean by USB2 I/O Inputs? Are you referring to the SEL1/SEL2 pins, or the USB1+/- and USB2+/- input pins?

    For SEL1 and SEL2, if the Vcc voltage is 3V, then the max input voltage going into those pins should be 3V.

    If you are referring to the data lane pins (USB1+/-, USB2+/-, D+/-), then the voltage being above Vcc should be fine, there should be no impact on the device or the signals.

    Please let me know if you have any other questions.

    Thanks,

    Ryan

  • Hey Ryan,

    I’m referring to USB2+/-, thanks

    On another thread it was posted that: the Diff pair IO pins and control IO pins of TS3USB3031 and TS3USBA225 are not fail safe pins, we do have concern for back drive current between  Diff pair I/O and VCC as well as  Select I/O and VCC

    just wanted to check and verify that the back drive current wouldn’t be an issue in the case where the vusb2 = 3.3 and the vcc = 3 as described above

     thank you

     Austin Allen

  • Hi Austin,

    Yes, it should still be fine. According to the datasheet, even with the difference in the data lane amplitude and Vcc, back-drive current should not be that significant.

    Please let me know if you have any other questions.

    Thanks,

    Ryan

  • Hi Austin,

    Any updated on this thread? Otherwise, I will mark it as resolved.

    Thanks,

    Ryan