I think most of us know not to route signals over plane breaks on PWBs as all kinds of bad things can happen when this occurs in a layout. But, how do you convince co-workers or your boss that a new design needs to avoid doing this even if added expense or project delay is required? Experimental data can be the key and this month my Technical Tidbit shows what happens to signal risetime if the signal crosses a plane break.
Crossing Ground Plane Breaks - Part 4 Risetime Effects on Signals Abstract: Signals that cross ground plane breaks on printed wiring boards (PWBs) experience degradation as well as cause EMI problems. Significant degradation of signal risetime is shown to occur, even with a relatively small ground break of five cm at risetimes on the order of 300 ps. The link to the article is the picture of the experimental test setup at the bottom of the home page at http://emcesd.com . Doug -- ___ _ Doug Smith \ / ) P.O. Box 1457 ========= Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: [email protected] \ _ / ] \ _ / Website: http://www.dsmith.org This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Mcantwell [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
