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How to match length of a differential Pair

Hossein1357

Hi,

I want to match the total length of my Diff pairs - all should be in a specified range in comparison to each other. I have defined an Electrical rule set and assigned some min/max margins. Then I assigned that ECS to my three differential nets and analyzed them. I found out that some of them are out of margin. Unfortunately, tune delay can only increase length of every single line not both!. I have some sample boards from various vendors which I see they were able to match diff pairs. I spent lots of time on it. I appreciate any help.

Thanks in advance,

Hossein

  • steve

     Take a look at http://www.parallel-systems.co.uk/images/PDF/diffpairs_definition.pdf but when using Delay Tune or Phase Tune if you want both members of the pair to tune together use Right click - and uncheck Single Trace mode.

  • Hossein1357

    Thank you Steve for your help. I will study document. However, I am pretty sure that I had disabled Single Trace mode and it still couldn't tune both pairs!. It is maybe related to improper settings of Differential Pairs.

     

  • Hossein1357

     Hi Steve,

    I read the document and it helped me a lot thank you very much. I am goign to keep a minimum distance between these pairs. I couldn't reach my design goals by defining Net Class-Class spacing. It seems to me that it is not operating properly. Would you please guide me on this issue as well?

    Thanks,

    Hossein

  • BK2018
    in reply to steve

    This still works!

    Thanks Steve!

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