• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 128 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.

Original question:

TUSB8044: TUSB8044 active reset: Hub cannot recognized by my SoC

TUSB8044: Schematic review

TISL
Expert 4900 points

Part Number: TUSB8044
Other Parts Discussed in Thread: TUSB322, TUSB542, , TUSB8020B, , TPS2561

Tool/software:

Dear USB-C team,

Could you help on the attached schematic review around our USB-C chips specifically (TUSB8044, TPS65988D, TUSB542, TUSB322, TUSB546 and TUSB8020)?

Regards,

Regards,Connect Board.zip

  • 0
    TI__Guru**** 153990 points

    Hi Tisl:

      I'm working on schematic review for TUSB8020B, TUSB542 and TUSB322 and TUSB546 and will be complete  by Friday.

    Please submit another ticket for TPS65988D review.

    Best

    Brian

  • +1 in reply to Brian Zhou
    TI__Guru**** 153990 points

    for U15 TUSB8044A

    1: need 1uf cap on GRSTz pin to Gnd.

    2: where is this Vbus from?

    3: both TUSB542 schematic looks good for side 1 and side 2 downstream port.

    for U24 TUSb8020B:

    1: need 1uf cap on GRSTz pin to Gnd.

    2: connect Vbus to TUSB8044A downstream port2 Vbus

    3: downstream port Vbus should  be controlled by  PWRCTLx for overcurrent case.

    4:  is U14 low enable? TUSB322 Id pin will keep high until an UFP device detected and going low.

    Best

    Brian

  • 0 in reply to Brian Zhou
    TI__Guru**** 153990 points

    also TUSB546 schematic looks good as well.

    Best

    Brian

  • 0 in reply to Brian Zhou
    TI__Expert 4900 points

    Many Thanks Brian, for you nice analysis.

    Here are below the customer feedbacks:

    • U14: The output is high if the SIDE2_PWREN signal is high (= no overcurrent) and the SIDE_PRES2_N signal is low (the system detects the presence of a connected connector)

    For questions around the VBUS, here is the current limiting architecture:  

    • There are two levels of current limitation
    • Level 1: VBUS is created from 5V. Nominal limitation at 2.644A. This is the "budget" of maximum current allocated to all USB ports that can potentially be supplied with 5V source at the same time.
    • Level 2: BAT_VBUS_REAR1/BAT_VBUS_SIDE1/VBUS_REAR2/VBUS_REAR3/VBUS_SIDE2 are coming from VBUS. Nominal limitation to 1.728A. This is the limitation of current for each USB port on the 5V source.

    About the other questions/comments:

    • U15 "where is this Vbus from?" --> so it is the "general" VBUS, after the first level of current limiting. From the point of view of U15, it is upstream.
    • U24 "connect Vbus to TUSB8044A downstream port2 Vbus" --> "downstream port2 Vbus" does not exist, or rather there are two: VBUS_REAR2 and VBUS_REAR3. Seeing no reason to connect one over the other here they considered that it was necessary to connect VBUS to U24 pin 9, even if it is upstream "through" U15. Which one seems to you to be the right solution?
    • U24 "downstream port Vbus should be controlled by PWRCTLx for overcurrent case." --> this is the case, via U12 (TPS2561)

    Regards,

  • +1 in reply to TISL
    TI__Guru**** 153990 points
    • U24 "connect Vbus to TUSB8044A downstream port2 Vbus" --> "downstream port2 Vbus" does not exist, or rather there are two: VBUS_REAR2 and VBUS_REAR3. Seeing no reason to connect one over the other here they considered that it was necessary to connect VBUS to U24 pin 9, even if it is upstream "through" U15. Which one seems to you to be the right solution?

               for U24, if connecting  VBUS to U24 pin 9, U24 is always on, if U15 in reset or something happened, since U24 RX_UP termination is always on, U15 DN2 may into compliance mode. 

                So for  hub  cascading   application, it's best to connect USB_Vbus of 2nd hub to the Vbus of 1st hub downstream port.

    Best

    Brian