Published by Eric Bogatin on 07 Aug 2012 at 08:13 am
Bruce Archambeault Kicks off the 2012 IEEE EMC Global SI and EMC University with a Tutorial on Inductance
“Not all EMC rules are created equal,” Bruce Archambeault, a distinguished engineer at IBM and industry icon introduced as the theme of his tutorial at the Global University.
New to this year’s Global University is a focus on signal integrity in addition to the traditional EMC topics. About 60 engineers attended the 16 different tutorials from industry experts.
In the first session was on PCB Layout for EMC Compliance. The subtitle for Bruce’s session was really, “All about inductance and return paths.”
Bruce started out challenging us to question the relative importance of some of the many design rules we use in board design. “Should decoupling capacitors be close to the chip?” Yes, he says, but this is not the most important rule to pay attention to.
Instead, he says, paying attention to return paths of signals and the inductance of each path is probably the most important design rule to follow. The loop inductance of signal-return paths influence the switching noise in all high speed systems. He went on to illustrate this principle by describing how geometry influences loop inductance and routing traces on aboard to control and minimize loop inductance.