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SN65LVPE502A: Compatibility Issue

Roy Hsu
Genius 9330 points
Part Number: SN65LVPE502A
Other Parts Discussed in Thread: SN65LVPE512, TUSB522P

Hi Team,

My customer feedbacked that they are experiencing some compatibility issue with our USB 3.0 redriver SN65LVPE502A.

What is the general approach that you would take to probe this kind of issue?

Is there any device that you know has less compatibility issue? (pin-to-pin compatible to SN65LVPE502A preferred)

Thanks! 

Roy Hsu

  • 0
    TI__Guru 64326 points
    Roy,

    What issues is the customer seeing specifically? Are the downstream devices failing to enumerate at Superspeed (USB3)or High Speed (USB2)? This is a general first step to help determine what is actually failing in the device. Next step would depend on the issue seen. You may consider SN65LVPE512 as a potential replacement.

    www.ti.com/.../SN65LVPE512
  • 0 in reply to Malik Barton57
    TI__Genius 9330 points

    Hi Malik,

    Yes, the downstream devices are failing to enumerate at SuperSpeed.

    When the customer USB device is connected to port1 or port2, it can’t be identified. But it can work normally when connected to port6 and port7

    Is there any reason that you recommended the SN65LVPE512? I found that this part is shown as NRND on ti.com. Do you still recommend this part?

    How is the SN65LVPE512 different from the SN65LVPE502A?

    Thanks!

    Roy Hsu

  • 0 in reply to Roy Hsu
    TI__Guru 64326 points
    Roy,

    SN65LVPE512 has better performance over SN65LVPE502A. Mostly both devices are very similar. I do still recommend this part even through it is NRND. Could you give more information on the trace lengths in the customers application? Has the customer probed the USB traffic to investigate any signal integrity issues? what settings have they tried with SN65LVPE502A?
  • 0 in reply to Malik Barton57
    TI__Genius 9330 points

    Hi Malik,

    It turns out that the Intel CPU that the customer is using changes the USB communication to the 2.0 standard when it enters BIOS, so that the USB 3.0 device can't be recognized.

    My customer has tried the 502A, 512 and 522P and found that only with the 522P can the device be recognized when in BIOS. Do you know what might be the reason?

    I am thinking about the Automatic LFPS Detection that the 522P has may be the reason. Do you agree?

    Thanks!

    Roy Hsu

  • 0 in reply to Roy Hsu
    TI__Guru 64326 points

    Roy, 

    This could be the case I will look into this and get back to you by tomorrow.Could you describe how the customer is testing this application? I want to make sure my understanding is correct. Could you describe the customer trace length and/or trace loss profile? What settings is the customer using for each device?

  • 0 in reply to Malik Barton57
    TI__Guru 64326 points
    Roy,

    I do not believe the LFPS detection of TUSB522P cause the system to work. All devices detect LFPS but the internal state machine does different things based on which device you are using. Making sure I understand the situation, once the CPU enters the BIOS ALL devices drop to USB 2 communication correct? Is the customer saying that with TUSB522P the USB 3.0 communication can be recognized? What kind of device or devices are they testing with? Can they try multiple devices if they are only using one device?