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 Differential Pairs 

Last post Tue, Aug 3 2010 9:48 AM by melview1. 4 replies.
Started by melview1 22 Jul 2010 09:50 AM. Topic has 4 replies.
Page 1 of 1 (5 items)
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  • Thu, Jul 22 2010 9:50 AM

    • melview1
    • Top 150 Contributor
    • Joined on Wed, May 20 2009
    • Shakopee, MN
    • Posts 41
    • Points 785
    Differential Pairs Reply

    Using OrCAD PCB Designer v16.3.S009

    Can anyone help me on how to route a differential pair to be the same length and same separation during the whole route?  I'm sure there's some properties or modes I am missing that makes this easier than doing it manually.

    Thanks.

     

    --Mark
    • Post Points: 20

  • Thu, Jul 22 2010 10:14 PM

    • redwire
    • Top 10 Contributor
    • Joined on Thu, Jul 17 2008
    • Allen, TX
    • Posts 813
    • Points 12,715
    Re: Differential Pairs Reply

    Constraint manager: set up the differential pair definition.  Then assign the net pair to that definition.  It will route automatically to your width + spacing requirements.

    • Post Points: 20

  • Tue, Aug 3 2010 8:53 AM

    • melview1
    • Top 150 Contributor
    • Joined on Wed, May 20 2009
    • Shakopee, MN
    • Posts 41
    • Points 785
    Re: Differential Pairs Reply

    I don't have a lot of experience with constraing manager.  I've been in it, but I'm not quite sure where I define distances between 2 nets.  Could I bother you for a bit more detail?

    Thanks.

    --Mark
    • Post Points: 20

  • Tue, Aug 3 2010 9:24 AM

    • oldmouldy
    • Top 10 Contributor
    • Joined on Tue, Jul 15 2008
    • Woking, Surrey
    • Posts 1,025
    • Points 17,250
    Re: Differential Pairs Reply

    You would need at least an Allegro PCB Design L license to get the necessary entries for differential pairs to appear in the Constraint Manager, the OrCAD PCB Designer has no native support for differential pairs.

    With Allegro PCB Design L, there is an additional Electrical domain in the Constraint Manager, this allows for the setting of the differential pair constraints.
    • Post Points: 20

  • Tue, Aug 3 2010 9:48 AM

    • melview1
    • Top 150 Contributor
    • Joined on Wed, May 20 2009
    • Shakopee, MN
    • Posts 41
    • Points 785
    Re: Differential Pairs Reply

    Well that sucks.  I guess I'll have to route them manually then.

    Thanks for the info.

     

     --Mark

     
    • Post Points: 5
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Started by melview1 at 22 Jul 2010 09:50 AM. Topic has 4 replies.