Re: [SI-LIST] : Complex Planes

danla (danla@emicx.mentorg.com)
Wed, 23 Sep 1998 08:58:49 -0700

Eric,
What you are talking about here is a "Slot" in the reference plane and
is considered a large problem for high speed designs. If you have
routing layers above and/or below that have nets crossing the "slot",
then you have effectively cut off the direct return path for current
causeing all of the return current to bend around the slot. This will
introduce a lot more crosstalk into all of those signals crossing the
slot because the are all sharing the same return current path. I can
give you a couple examples if that was not clear enough. The quality of
that one trace in the slot is not the issue here at all, it's what you
will do to all of the other signals that perpendicular region for their
return current. I hope that helps you.

-- 
Dan Lake
danla@icx.com

Software Support Engineer Interconnectix

Mentor Graphics Corporation 8005 SW Boeckman Road Wilsonville, OR 97070-7777 Support: 800-547-4303 Fax: 503-685-4897

Eric B. Lewis wrote: > > Does anyone no where I can fine any information on complex planes. > > I don't have a signal integrity tool at my immediate disposal, > but I'd like to find out the possible pitfalls of routing certain > non-clock signals on a Ground plane. > > Eric B. Lewis > VoiceMail:972.575.7798 > Pager:972.598.3852 > Raytheon TI Systems > 6600 Chase Oaks Blvd. > Plano, Texas 75023 > > **** To unsubscribe from si-list: send e-mail to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at

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