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TUSB211: Can this situation use tusb211?

user4990752
Prodigy 50 points
Part Number: TUSB211

Hi,

I have some question about TUSB211.  

We attached two USB cameras to the arm robot and used the wiring through the robot.

After that, because of ease of maintenance, we split the cable into seven parts and attached the connectors to each, but the camera did not work well.

I thought that the cause of the problem was increased contact resistance due to the connector being attached.

Therefore, referring to the circuit diagram of the USB 2.0 and 3.0 re-driver evaluation module (www.tij.co.jp/.../usb-redriver-evm),

I made a USB re-driver circuit incorporating TUSB 211, but it did not work well.

So there are some question,

· Can TUSB211 be used even in such a case?
· If it can be used, it is about 2 m cable, so Is TUSB211 suitable for one use?

I would like you to tell me about two points.

As a reference, I put the circuit diagram of the USB 2.0 redriver circuit I made.

Beat regards,

  • 0
    TI__Mastermind 36085 points
    Hello,

    Perhaps the issue lies in the loss due to resistive loss. The TUSb211 compensates the USB2 signal by injecting current, this improves the slew rate but you still have the VOD loss due to resistive parasite elements. Please take eye measurements and depending on the loss you can follow one of this workarounds:

    If the eye height is marginally good, then adjust the strength of the signal (you have to configure the camera and Host do this - if possible). Another.
    Use cable and connectors with lower resistance, also reduce the number of connectors if possible.
    Place a USB2 HUB in the middle (like the TUSB4020B), this will re-transmit the HS signals and overcome the DC loss.

    Regards,
    Diego.
  • 0 in reply to Diego Cortes
    Prodigy 50 points

    Hi,

    Thank you for your immediate reply.

    There is something I want to ask again based on the previous reply.

    As of now, we can not reduce the number of connectors, so we can not lower the cable resistance. In addition, we can not observe eyes because we do not have measuring instruments.

    It is a question about the part under the reply of the other day.

    > This (TUSB211) improves the slew rate but you still have the VOD loss due to resistive parasite elements.

    That means that the TUSB211 is only for conditioning the high speed signal to clean the eyes and not to amplify the strength of the signal attenuated by the resistance, right?

    Also, since TUSB4020B overcomes the resistance, do you think it is appropriate to use it to overcome the contact resistance increased by the contact resistance of the connector like this time?

    Best Regards,

    ichioka

  • 0 in reply to user4990752
    TI__Mastermind 36085 points
    Hi Ichioka,

    You are correct, the TUSB211 does not amplify the signal strength. If possible please configure the Host & device to increase the drive strength.

    The Hub will repeat the USB signal and split the HS channel, therefore is like having the HOST at the downstream port of the TUSB4020B. The usage of a HUB is commonly used in automotive applications where you have a USB connector far away from the HOST.

    Regards,
    Diego.