DP83867IR: voltage differences for TDSET3 Ethernet Compliance Test

Intellectual 865 points

Replies: 6

Views: 142

Part Number: DP83867IR

Hi,

my customer is using DP83867IR and sees voltage differences higher 1%, mostly 2 % which is a problem.

they use the 1000BASE-T STandard with our DP83867IRRGZ and use the TDSET3 Ethernet Compliance test.

DO we also test that on our devices?

If yes, can you send me the results?

What could be a cause of this percentage voltage deviation?

Thank you for your help,

kind regards,

Marion

6 Replies

  • just to add for your understanding.

    The test was performed under the guidelines of "How to Configure DP838xx for Ethernet Compliance Testing" - our app note.

    It was measured with a DPO7245 with differential probe P6248.

    the deviation is measured with the peak voltage test (2.2.2).

    Thank you for you efforts,

    Marion

  • In reply to Marion Loessl:

    Hi Marion,

    Are they following the same register configurations that are in the app note?

    We test PMA using the same software and also run at a 3rd party test house called UNH IOL.

    Please send me the schematic of the customer board for the 867 as well as part number for the magnetic they are using.

    Best regards,

    Ross Pimentel

    Ethernet - Applications Engineer

  • In reply to Ross Pimentel:

    Hi Ross,

    I got the required input but I don't feel comfortable posting them.

    I'll  provide them in a separate private mail and you can comment then.

    Kind regards,

    Marion

  • In reply to Marion Loessl:

    Hi Marion,

    Thank you for the data and the schematic.

    I looked at the magnetics but could not find any details on their winding accuracy.

    Could you check with the customer to see what those specs are?

    Please have them re-run with the ESD removed. I would like to see how much those external devices are influencing the symmetry.

    When they do the testing, what length cable are they using for the TDSET3? Is it the short standard cable that comes with the software suite?

    Best regards,

    Ross Pimentel

    Ethernet - Applications Engineer

  • In reply to Ross Pimentel:

    Hi Ross,

    do you mean by removing ESD?

    Kind regards,

    Marion

  • In reply to Ross Pimentel:

    Hi Ross,

    I have some answers from the customer:

    1) ESD Protection and Cable Information: 
     
    I wrote a protocol about the measurements I made referring to this problem. I tested two different cables and unsoldered the TVS Diode. There was no improvement trough this steps. The results of chapter 2.2 and with the black cable are measured with the short cable included in the compliance test hardware.

    2) Connector/Transformer:

    We are using connectors with integrated transformers marked as suitable for 1000 Base-T. Are there any special requirements by the Phy? I will request that parameters by the manufacturers if you could give me some more information about that. (As I can not find any more detailed information inside the datasheets either for the winding accuracy). 

    I'm still awaiting, what you meant by removing ESD.

    Please provide an answer as soon as possible.

    Kind regards,

    Marion