[PCB_FORUM] Re: Diff pair setup in Constraint Manager
- From: Randy Dawson <rdawson16@xxxxxxxxxxx>
- To: icu-pcb-forum <icu-pcb-forum@xxxxxxxxxxxxx>
- Date: Fri, 15 Feb 2013 09:01:33 -0600
Hi Gary,
If you set it up as an electrical constraint, its dimensions will change with
stackup changes (as the impedance is stackup dependent).
As a physical constraint, they do not.
There are reasons to do it either way, for example you want to preserve or
reuse some physical routing rules from a prior design, you would set
constraints as physical, and adjust stackup accordingly.
Likewise, if you are modifying stackup, you want the dimensions to track your
changes to maintain impedance.
Randy Dawson
From: Gary.Macindoe@xxxxxxxxxxxx
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] Diff pair setup in Constraint Manager
Date: Fri, 15 Feb 2013 14:47:50 +0000
Hey guys,
You know, this has always been a mystery to me, where to set up diff pairs in
CM.
Should you create a differential impedance Electrical Constraint Set under the
Electrical tab, or a Physical Constraint Set under the Physical tab?
It appears that you can set it up in either place and get it to work.
How do you guys do it, and why?
Regards,
Gary MacIndoe
Senior PCB Design Engineer
EbD R&D Hardware
Surgical Solutions Group
Covidien
5920 Longbow Drive
M/S A20
Boulder, CO 80301
303.476.7458
www.covidien.com
Other related posts:
