• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 34 subscribers
  • Views 461 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.

TUSB4041I-Q1: Pin 16 usb_vbus power supply timing

Alpha Han
Expert 3790 points

Part Number: TUSB4041I-Q1

Hi, Team:

Now customer is using TUSB4041I-Q1 in the same PCB board with Qualcomm S820 processor. So, there will be no USB connection action for the upstream port. 

Can you help to check and advise what's the requirement for Pin 16 usb_vbus  power supply timing in this condition?

If it need to power on before or after VDD and VDD33?

  • 0
    TI__Guru 60870 points
    Hi Alpha,

    USB_VBUS must be high for the hub to make an upstream connection. USB_VBUS can be high before or after the TUSB4041 powers on, but to prevent any issues where the host or the hub attempts to connect before the other, I would recommend USB_VBUS turn on after the host and the hub have completed power on reset.

    If using a 3.3V signal to drive USB_VBUS, the resistor divider network values will need to change from 90.9K / 10K for 5V to 90.9K / 17K for 3.3V.

    Regards,
    JMMN