Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State TI Thinks Resolved
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 32 subscribers
  • Views 73 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

Original question:

TUSB1142: TUSB1142 fail USB compliance test TD 7.31 Hot reset failure test

TUSB321: DIR transition time clarification

Alder Lim
Prodigy 170 points
Part Number: TUSB321
Other Parts Discussed in Thread: TUSB1142, TUSB322I

Tool/software:

Hi TI guru,

I am using TUSB321 pair with TUSB1142. We measure the transition time for the DIR pin to toggle with reference to Vbus_Det when flip the Type C cable, it is about 113ms.

Questions:

1. Is this normal? we are thinking this is too long...

2. I can not find the detect to DIR transition time information in datasheet, what is the typical also min and max?

3. Any recommendation to reduce the DIR transition time? 

4. Does TUSB321 go through USB compliance test and do not have any waiver ? (except for the USB type-C 1.0 DRP device that mention in the datasheet...)

5. Does TI have any test on the combination for TUSB321 + TUSB1142 ? Is there any know issue/errata/waiver ?

6. Any USB compliance test done for TUSB321 + TUSB1142 combination?

Thanks,

Best regards,
Alder

  • 0
    TI__Mastermind 20760 points

    Hi Alder,

    1: The TUSB321 will debounce the CC lines and VBUS_DET pin before setting outputs like DIR and ID. This could explain the 113ms transition time you're seeing:

    2: I'm not sure whether we've speced min/max values on this parameter. I can follow up on this with our systems engineer when they return to the office. 

    3. Since the TUSB321 is GPIO mode only, we do not have a way to adjust the DIR transition time. The TUSB322I has a register in I2C mode to adjust the CC pin debounce time, which may help:

    4. The TUSB321 has been used in multiple customer systems that have passed the USB C functional test specification. I am not aware of any waivers needed to pass these tests.

    5. We have not run tests with these parts together, however we have tested both parts independently. The TUSB1142 has passed USB TX and RX compliance when paired with a compliant source while the TUSB321 has been tested for type-C compliance by our customers. Since the TUSB1142 is a linear re-driver, it will reproduce whatever signal is received from the host or device. As long as the connected host or device is compliant the TUSB1142 should pass.

    6. We do not have compliance data with both of these devices together.

    Best,

    Shane

  • 0 in reply to Shane Hauser
    Prodigy 170 points

    Thank you Shane, I saw it is about 100ms++ for ID to react (Figure 5 datasheet) and that is for DFP mode, there will be about same for UFP mode, right ? The spec below should be for all, DRP, DFP and UFP, right ?

    Thanks,
    Best regards,
    Alder

  • 0 in reply to Alder Lim
    TI__Mastermind 20760 points

    Hi Alder,

    You are correct, these specs apply for DFP, DRP, and UFP modes.

    ID should only transition low if the TUSB321 is configured for DFP or DRP mode and acting as a power source.

    Best,

    Shane

  • 0 in reply to Shane Hauser
    Prodigy 170 points

    Thank you Shane,

    1 more question on TUSB321.

    If i have 1 board for TUSB321 set as Source (Both CC lines high, Rps) and 1 board for TUSB321 set as Sink (Both CC lines low, Rd), if i flip the type C cable, how the detection work?

    Thanks,
    Best regards,

    Alder