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Why TUSB2046BI get into Suspend mode frequently?

Ian Lu
Prodigy 40 points
Other Parts Discussed in Thread: TUSB2046B

Hello,

I have a problem about the suspend mode of TUSB2046BI of my new designed cradle which made for industry PDA.

The problem occur after plug in the PDA and it get into suspend mode around twice of ten times. 

The OS of PDA is WINDOWS CE 6.0 and Mobile 6.5.

 My schematic diagram is all refer to the reference design/ Self-Powered Hub Individual-port power management.

The RESET is active LOW by RC circuit, R=10~15K, C=0.1uF~1uF.

It is working normally when replace the PDA by PC/ Windows XP

Kindly give me a hand and show me the solution.

Thank you so much.

Ian

  • 0
    TI__Guru* 76130 points

    Hello Ian,

    A USB device (like the TUSB2046B) cannot put itself into suspend mode, the host controller is the one that puts the usb devices in suspend mode.

    You may want to check the following cases in which the host will suspend a usb device:

    The host can suspend the hub if it sees 3 ms of no bus activity.
    If the downstream devices pull more than 500 mA of current, the hub goes in to SUSPEND state since it is violation of USB specs. Also, if the reset timing isn’t accurate or if the host doesn’t load the hub class driver correctly, the hub goes in to SUSPEND state and shows us as an “Unknown device” in device manager.

    Also, you can send your schematics for review.

    Regards.

  • 0 in reply to Elias Villegas M.
    Prodigy 40 points

    Hi Elias,

    Thanks for your prompt reply.

    I think I need to describe more details.

    Some of the samples got this problem only around 5%.  

    Kindly refer to attached schematic for reference.

    Ian 

     

  • 0 in reply to Ian Lu
    TI__Guru* 76130 points

    Hello Ian,

    The quality of the image is not very good, I can't see the names of the terminals, can you send another capture?

    If you don't want to post your schematics, you can email them to elias.villegas@ti.com

    Regards.