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TUSB2046B: USB Memory Recognition Fail

Part Number: TUSB2046B


Customer is encountering problem regarding the device. Below is the summary.

1) The mouse and keyboard recognize, but not the USB memory stick.
2) It is recognized when connecting a memory stick by connecting a USB HUB to the outside.

Mouse & Keyboard <--> TUSB2046B <--> Processor : recognize
Memory Stick <--> TUSB2046B <--> Processor : Unrecognizable
Memory Stick <--> USB HUB <--> TUSB2046B <--> Processor :  recognize

Thank you in advance.


  • Hi Maynard,

    Can you confirm if the hub is configured in buspowerd mode or selfpowered mode?  If it is in buspowered mode, please try switching to selfpowered mode.  What is the bus state on DP/DM when the memory stick is connected?



  • Hi JMMN,

    Thank you for your respons, below is the reply of the customer.

    I'm using self-powered mode.
    What does the second question mean?

    Best regards,

  • Hi Maynard,

    Can they check what signaling is occurring on the downstream port DP/DM lines when the memory stick is connected?

    Does the host report any error messages?

    Can the customer confirm that VBUS stays above 4.75V when the memory stick is connected?