• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 21 subscribers
  • Views 215 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.

TUSB8041:Schematic Review Request for TUSB8041-Based USB Hub Design

Adam Austin
Prodigy 110 points
Part Number: TUSB8041

Tool/software:

Hi,

I am currently designing a custom USB 3.0 hub based on the TUSB8041 and I’ve completed the schematic for the core part of the design. I would really appreciate it if you could take a moment to review the attached schematic and let me know if there are any issues or recommendations — especially regarding:

  • Power supply filtering and sequencing

  • Crystal and load capacitor configuration

  • USB_VBUS handling

  • SMBus/I²C configuration

  • General best practices

Please find the schematic attached.
I look forward to your feedbackJob1.pdf.

  • 0
    TI__Guru*** 146055 points

    Hi I'm working on schematic review and will be complete by Mon.

    Best

    Brian

  • 0 in reply to Brian Zhou
    TI__Guru*** 146055 points

    Here is my comment for schematic:

    1: SMBUS is low, are you going to change hub configuration ?

    2: How do you control Vbus for downstream port?

    3:  USB_VBUS pin threshold  is  around 400mv, looks ok.

    Regards

    Brian

  • 0 in reply to Brian Zhou
    Prodigy 110 points

    1.I actually want the hub to operate in standalone mode, but I also connected it to the Raspberry Pi’s I²C bus. Initially, I thought this pin (SMBUSz) enables I²C communication, but now I see that it selects between EEPROM and I²C/SMBus mode. If I pull this pin directly to GND, the hub will work standalone and the I²C slave interface will also be active.

    2

    For downstream VBUS control:

    • We have two external downstream ports connected to USB connectors.

    • These two ports share the same power rail, and we connected the PWRCTL signal only to one of the two ports' enable pins (the other is always powered when that rail is on).

    • The third downstream port is internal, connected to a specific USB 2.0-only device inside our system. This device is powered through a regulator that is enabled by the PG (Power Good) pin of the TUSB8041’s internal 1.1V LDO.

  • 0 in reply to Adam Austin
    TI__Guru*** 146055 points

    for 1, when SMBUZ is low, SCL/SDA is still active for SMBUS communication, hub is in SMBUS receiver mode.

             When SMBUS is high, hub i sin I2C master mode, it only read external EEPROM.

    Best

    Brian