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TUSB2046B Design problems

Other Parts Discussed in Thread: TUSB2046B, TPS2044, TPS2044A

Hello,

I have designed a USB Hub using the TI TUSB2046B Chip. Attached is the picture of the schematic.

For some reason I am not able to get the desired outcome.

We are not using the EEPROM, so the EECLK is left floating

Pin 32 is NC

Pins 27,  7, 28, 31 are tied to GND

Pins 3 & 25 have VCC.

When I power up the circuit, it doesn't recognize the chip, apart from a message saying Power surge on the USB Hub.

Do we need to add something to this cirucit? Between TPS2044 & TUSB2046 to make it work?

Please let me know so we can fix this.

Thanks

Jas

  • Jas,

    Are any devices connected to the downstream ports when you connect the upstream port to the host PC?

    How are you generating your Vcc for the hub itself?

  • Hello Dan,

    The four USB Downstream ports will be used to interface WiFi, mouse, keyboard, CANBUS Module.

    The 3.3V is generated from a regulator (12V to 3.3V, Belfuse SRBA series part).

    Jas

  • Jack,

    When the power surge message is received, are the devices connected or is it just the hub that causes this message?

    Have you tried connecting the devices one at a time to determine if it is one of the devices that causes the surge

  • Hello Dan,

    There is no 5V getting to any of the USB Ports, so they will eventually not work. I am trying to add the pull up resistors, as these were not there previously and also connecting the right pins to ground & VCC on the 2046B Chip. If that doesn't work, then there is something more to look at.

    I will share my results with you sooon.

    I got the GSM to work about 10min ago, and feel good about that!!

    Regards,

    Jack

  • Hello Dan,

    I did put a 10k res to pull up the OVRCUR pins to 3.3V and did all the right conections, still not USB :-(

    Should I use a different value resistor?

    Anything you can suggest would be good.

    Jack

  • Hello Dan, Can there be something with the RESET button (Pin 4). I have connected this to 3.3V via a RC Circuit.

    Realy running out of time & patience here with the TI Part. Hope this gets resolved sooner than later.

    Thanks

    Jack

  • Hello Dan,

    Are the ports coming out of TUSB2046 Hub fully USB2.0 Compliant?


    Jack

  • Jack,

    The TUSB2046B is fully compliant as a USB 2,0 FULL-SPEED (12 Mbps) hub for embedded applications.  It does not support USB high-speed transfer rates, but will allow high-speed peripherals to operate, but just at USB full-speed transfer rates.  The device is on the USB-IF Integratorr's list and was the hub used for many years in the USB-IF Interoperability Test Suite - now they use high-speed capable hubs.

  • Jack,

    Does the power surge message appear even if there are no downstream devices attached to the TUSB2046B?  If the hub is self-powered I'm confused why a power surge message would even appear.  Where is VBUS from the upstream USB connection routed?  Typically if a USB host sees an overcurrent condition it will not load drivers for the downstream devices and will disable them until the host is power cycled.  Is the TUSB2046B embedded (always connected)?

    Regards,

    Julie

  • Hello Julie,

    We have USB (DP & DM) coming from Intel Atom Processor, which we are connecting to the TUSB2046 Hub. There is no power surge message appearing any more. It was only once in the begening and I have not seen it since.

    The TUSB2046 is powered with 3,3V coming from a 12V to 3.3V Regulator, as described earlier. The design is for a self powereed individual port power management.

    I am having issue with it still and not able to resolve. Can you suggest something that we can do in our schematic to overcome this problem and make it work!

    Thanks

    Jack

  • Hello Julie,

    I have made the necessary changes to the circuit. Now when I connect the (mouse), it detects it but shows it as an Unknown device.

    The light on the mouse t urns on and then goes off all of a sudden.

    Is something triggering this?

    Jack

  • If you connect the mouse directly to the host port, is it recognized?

    "Unknown" devices indicate software issue - no driver available that recognizes the hardware.

  • Jack,

     

    Can you check the status of the SUSPEND output, PWRON output and the OVRCUR input?

  • Hello Dan / Julie,

    Thanks for the replies. The Hub works fine now.

    Problem 1: D+ & D- lines on the downstream were swapped!! Pin 2 was assigned D+, when it should have been D-, per USB Standards.

    Problem 2: The cap's on the OUTput of TPS2044 where fitted the wrong way! Polarity reversed.

    Issues resolved now. All good.

    Thanks

    Jack

     

  • Hello Jack,

                            I am also working with TUSB2046B  in Self-Powered Hub, Individual-Port Power Management mode. PWRON1bar-PWRON4bar is connected to EN1bar-EN4bar pins of TPS2044A. The o/p voltage at each PWRONbar pin is 3.28V. What should the output of the PWRONbar pin be?? There is no 5V getting to any of the USB Ports.What can be the problem..? Can you please share your schematic. So I can resolve my problem. Thanking you.

     

    Regards,

    Kishor

  • Hello Kishor,

    Have you solved your problem?

    Does your Hub is detected by Host ( PC or Laptop ) ? Host performs set port power request after configuring hub. Based on this request, Hub enables port power.

    By the way, PWRON1bar seems active low pin. (Due to bar suffix).If it is,then after hub is detected by Host (PC/Laptop) that pin should go low.

    Regards,

    Bhaumik