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TUSB2077A: Some quesitons

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Replies: 8

Views: 89

Part Number: TUSB2077A

Hi Sirs,

Sorry to bother you.

We have using TUSB2077
Some of the MB failed.
In the absence of device state
OVRCUR# is high and PWRON# is also high
That will make TI_TPS2044BDR unable to output power.

I  modified the timing of the reset pin
Some fail boards PWRON# will be normal, but others board still fail.

Could you help check it?

Another question
Software reply under a USB flash drive
USB HUB transmission speed is about 959kB/s
Is there a HW strap to fix at high speed??

 

 

  • Hi,

    TUSB2077 is a USB Full Speed hub only and cannot operate at USB High Speed. Does this failure occur when a device is connected? Do you have a schematic that can be reviewed?

  • In reply to Malik Barton57:

    Hi Sirs,

    Thanks for your reply.

    Please refer our schematic as below

    NL is reserved.
    The schematic is designed to be self-powered, individual-port power management

  • In reply to Shu-Cheng LIN:

    Hi,

    What is the failure seen when testing? There are no obvious errors in the schematic. 

  • In reply to Malik Barton57:

    Hi Sirs,

    Thanks for your reply.

    The issue  is transmission speed too slow.
    TUSB2077 only Full speed
    However, the measured USB HUB transmission speed is only about 959kB/s.
    Is there a way to adjust??

  • In reply to Shu-Cheng LIN:

    Hi,

    There is no setting to adjust the transmitted data rate. How is this being measured? What is the customer expecting to see? How many devices are connected to the USB Hub during testing? How many board see this this "lowered" data rate?

  • In reply to Malik Barton57:

    Hi Sirs,

    Thanks for your reply.

    Our software test  use "one" USB flash drive
    Transfer a large file with a fixed capacity

    For example, 10MB is completed in ten seconds, and one second is 1MB.
    Currently the boards are in the low speed state.


    The others words,
    Is the downstream transmission speed of the TUSB2077 dependent on the upstream??

    What situation could be full speed?

  • In reply to Shu-Cheng LIN:

    Hi,

    TUSB2077A cannot enumerate as a low speed devices due ti the pull up resistor on DP. (this resistor indicates FS devices per USB spec.) The lowered speed may be due several factors external to TUSB2077A such as SI conditions (long trace or cables) and SOC software. TUSB2077a also does not have any internal memory so TUSB2077A cannot be holding traffic back from the device. You can also check that TUSB2077A has enumerated at FS by using USBTree or USBView software and checking USB descriptors. 

  • In reply to Malik Barton57:

    Is there any more support needed for this issue? If so please reply with any relevant details so that I can further assist you. For now I will be marking this thread as "TI Thinks Resolved". If you have resolved your issue, please post the solution to the original problem/post for others with similar issues.