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Original question:

TUSB8041: USB Type C Connection

TUSB8041: USB-C Port Schematic Review (HD3SS3220)

Don Pitchford
Intellectual 255 points
Part Number: TUSB8041
Other Parts Discussed in Thread: TPS2561, TPS25751, HD3SS3220, TPS2560, TUSB320LAI, TUSB320

Tool/software:

Hello,

I would like to request a schematic review of my USB-C interface implementation using the TUSB8041 USB 3.0 hub. Below is an overview of the system configuration and specific use cases per port:

System Overview

  • Upstream Port (USB-C Internal):

    • Connected to an internal USB-C connector within the enclosure.

    • VBUS is used only for presence detection, not for powering the hub.

  • TUSB8041 Downstream Ports Configuration:

    • Port 1:

      • Connected to an internal USB-C connector.

      • VBUS is controlled via a TPS2561, and I would like to enable/disable this port via I²C to support device resets or power cycling.

    • Port 2:

      • Connected to an external USB-C port.

      • This port’s VBUS is routed to a TPS25751, which acts as a power sink and delivers power to the system.

      • Data (USB2.0 & Super Speed are routed back to the hub).    Would like to be able disable the port, but not sure how if the power going to another chip.

    • Port 3:

      • Routed to an internal USB 2.0 interface, with no physical USB connector.

      • This port is used for onboard communications only.

    • Port 4:

      • Connected to the upstream port of a TUSB4041 USB 2.0 hub to support four additional USB 2.0 ports.

Design Intent

  • The TUSB8041 is configured via strap pins only (no EEPROM).

  • I would like to retain I²C connectivity to the host processor for optional runtime control, primarily to power cycle Port 1 & 3, able shut off 2 completely (security protection if needed).

  • The system is self-powered. All required voltages are derived from internal regulators, and the hub does not rely on upstream VBUS for operation.

Review Questions

  1. Is my strap-based configuration valid for enabling all ports (except Port 2 data) without using EEPROM or SMBus mode?

  2. Can I safely use I²C for optional runtime control while still allowing the hub to enumerate and function with default settings?

  3. Does the integration of TPS2561 on Port 1 and Port 3 for power control align with TUSB8041’s PWRCTL/OVERCUR expectations?

  4. For Port 2  is it correct to:

    • Leave PWRCTL2 and OVERCUR2z strap to 3V3?

    • USB Super Speed signal, with VBUS to TPS25751

7848.page2.pdf  Schematic For TUSB8041 with USB-C interface

  • 0
    TI__Guru*** 146695 points
    Don Pitchford said:
    Is my strap-based configuration valid for enabling all ports (except Port 2 data) without using EEPROM or SMBus mode?

    you can enable all ports without EEPROm or SMBUS.hub 

    Don Pitchford said:
    Can I safely use I²C for optional runtime control while still allowing the hub to enumerate and function with default settings?

    hub I2C is master mode, it's used only for external EEPROm, you can not ocntrol hub by I2C controller.

    Don Pitchford said:
    Does the integration of TPS2561 on Port 1 and Port 3 for power control align with TUSB8041’s PWRCTL/OVERCUR expectations?

    for typr-C, you need to use CC controller ID pin to contorl port Vbus, not hub PWRCTL

    Don Pitchford said:

    For Port 2  is it correct to:

    • Leave PWRCTL2 and OVERCUR2z strap to 3V3?

    • USB Super Speed signal, with VBUS to TPS25751

    you can leave PWRCTL2 floating nd OVERCUR2 to 3.3v

         I'm working on review schematic and will be compelted soon.

    Best

    Brian

  • 0 in reply to Brian Zhou
    TI__Guru*** 146695 points

    for downstream port , it should be configured as DFP(PORT=H), and use ID pin to control Vbus controller.

    Regards

    Brian

  • 0 in reply to Brian Zhou
    Intellectual 255 points

    Thank you for pointing out the issue with the PORT pin — I have now tied it high through a 200 kΩ resistor to configure the HD3SS3220 as a DFP (host).

    Since the ID pin is active low, I’ve also switched from the TPS2561 to the TPS2560 to match the correct enable logic.

    Based on your feedback, it appears that even for a USB-C 2.0 DFP port, the HD3SS3220 is still needed to handle CC line negotiation and to control VBUS through the ID signal. I've added the HD3SS3220 accordingly.

    Could you please take a look and let me know if this updated configuration looks correct?  I would also like to be able shut down these ports (1 & 2) via host processor.   I was going to use NOR gates to take signals from both the HD3SS3220 and my host processor.  Is this the correct way to control and reboot the device?

     output1.pdf




  • 0 in reply to Don Pitchford
    TI__Guru*** 146695 points

    I'm working on schematic review and will send my comment  by tomorrow.

    Best

    Brian

  • 0 in reply to Brian Zhou
    TI__Guru*** 146695 points

    If  only need USB2, you can use CC controller TUSB320LAI to replace HD3SS3220. 

    Don Pitchford said:
    I would also like to be able shut down these ports (1 & 2) via host processor.   I was going to use NOR gates to take signals from both the HD3SS3220 and my host processor.  Is this the correct way to control and reboot the device?

    yes, you can do that.

    Best

    Brian

  • 0 in reply to Brian Zhou
    Intellectual 255 points

    Great idea.  I replace the HD3SS3220 with the TUSB320.     On the TUSB3220, the ID pin still controls the TPS2560.    I forced it in DFP mode by tying the port high.  What do you think, any issues? 

  • 0 in reply to Don Pitchford
    TI__Guru*** 146695 points

    You still need pullup on ID pin.

    Best

    Brian

  • 0 in reply to Don Pitchford
    Intellectual 255 points

    Brian - Great catch.   Thank you again for your help and timely response.   Unless you see anything else, I don't think I have any other questions.   Here is my final schematic that might help someone else who have similar questions. 

     0753.output1.pdf