I have recently been blogging about signal and power integrity, how the two are related, and how they can cross over. This was prompted by an article I recently wrote for the DesignCon branch of EDN. Twenty years ago, one of the biggest barriers to designing high-speed PCBs was ensuring signal integrity. About ten years ago, power integrity started becoming a serious issue. So what is next? Is there another type of “integrity” we need to start analyzing?
No – at this point we pretty much have everything covered. No more integrities on the horizon. But what likely will change is how much we analyze in each of these analysis types… For instance, if we look at vias, they used to be short enough to just model as a simple capacitor, then a simple L-C, and now for high-speed differential signals we need a full-wave 3D EM model of the via to properly characterize it for simulation. For single-ended vias, we need to know the entire PDN to get an accurate signal model for the via. And that is another trend that is permeating analysis needs – the impending crossover between signal and power integrity. Eventually integrity analysis will encompass both, as well as other disciplines, all on the way to being able to create “virtual prototypes” of our PCBs, being able to predict their performance in a number of realms before the first prototype is manufactured.