[SI-LIST] : Differential pairs and place splits

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

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