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TUSB2077A: TUSB2077A : Unknown USB Device Problem

JiSoo Kim
Prodigy 10 points
Part Number: TUSB2077A

TUSB2077A.pdf

Hello.
Recently, I tried to construct a circuit that automatically connects various sensors to the hub using TUSB2077AIC.
As you can see from Schematic, each communication component is connected from a PCB instead of physically plugging it into a USB socket.

However, there may be a problem with the circuit, and no matter how hard I try, the circuit does not work.

When I checked for errors in Device Manager, the following error appears.

"Unknown USB Device (Device Dexcriptor Request Failed)"

Windows has stopped this because it reported roblem(Code 43)

Please help me solve the problem....
P.S : I added the 1.5K resistor to crystal line

  • 0
    TI__Guru*** 132360 points

    1: pls check if crystal works.

    2: hub didn't show up at devce manager, so hub upstream not working?

    3" what is this for?

    Best

    Brian

  • 0 in reply to Brian Zhou
    Prodigy 10 points

    1. Crystal isn't working... It just shows DC voltage.
    2. Yes. Hub Upstream isn't working...
    3. My team member says it's just an LED to see the status of USB communication.
    Thank you for your quick response.

  • 0 in reply to Brian Zhou
    Prodigy 10 points

    Dear Mr.Brian

    I found some problem from schematic. The Resistor that is connected to DP0PUR was Wrong. I changed that to 1.5k Ohm resistor.

    Now my laptop recognizes my circuit as USB HUB.

    There is still a problem that the crystal only oscillates in only Reset state, but I will continue to solve it. Thank you for your kind reply.

  • 0 in reply to JiSoo Kim
    TI__Guru*** 132360 points

    great, keep update status.

  • 0 in reply to Brian Zhou
    Prodigy 10 points

    Hello Brian.
    As I told you, I'm trying various things. After Changing DP0PUR Resistor, My laptop recognizes my board as USB HUB Now. But Still There are no downstream devices are detected from my device manager.(CH340, CP2104, Etc... ) Do you have any additional advice?

    Thank you always.
  • 0 in reply to JiSoo Kim
    TI__Guru*** 132360 points

    for downstream port, you need to move cap close to hub, and 15k close to connector.

  • 0 in reply to Brian Zhou
    Prodigy 10 points

    Dear Brian. 
    Thank you for your kind reply. I just changed Capacitor with Pull Down Resistor, But It doesn't work.

    I found that the capacitor connected in series to the reset side was too small, so I changed it too(Still not working)...

  • 0 in reply to JiSoo Kim
    TI__Guru*** 132360 points

    1: is crystal stable?

    2: do you have 5v to downstream port?

    3: maybe remove this parts first.

    Best

    Brain

  • 0 in reply to Brian Zhou
    Prodigy 10 points
    Thank you for your quick response

    1.It's a little unstable. When it connected to Laptop, usually doesn't work. But it works most of the time when I reconnect it to my laptop.

       I think this problem also should be solved, but I'm trying solve the down stream issue(because i think down stream issue is more serious)

    2.Yes. All the down stream port has 5V which is provided by extra power, not USB Port

    3.I just removed that circut from few ports, but it wasn't work. In fact, There are no D+/D- signal from USB-UART IC. But They make D+/D- Signal when they connected to Laptop as Several Module...

  • 0 in reply to Brian Zhou
    Prodigy 10 points

    Dear Brian. I Just Solve the problem. I found that Pin8(EEDATA/GANGED) is floated, so i connected them to 3.3V. Now my board recognize the downstream IC. 

    Thank you for your continued interest and help!