[SI-LIST] : Differential pairs and place splits

Young, Randy (ryoung@SCDC.Cirrus.com)
Tue, 10 Feb 1998 09:50:21 -0500

Hi,
I understand that in general, routing high-speed digital traces across
plane splits is a bad idea from both a signal quality perspective and an
EMI perspective due to return current paths. My question is concerning
differential pairs - specifically, USB and 1394. Do the same rules
apply? Is routing a differential pair across a plane split bad from
either signal quality or EMI perspective? My assumption is that the
return current path for a differential pair is the other trace of the
pair, and that this would greatly reduce any signal quality or EMI
problems associated with crossing splits. Is this correct?

Randy Young
ryoung@scdc.cirrus.com