FUNDAMENTALS AND RECENT ADVANCES IN POWER INTEGRITY

Although signal and power integrity practices are as old as the digital design itself, unlike SI, PI still remains an elusive concept in the eyes of industrial circles. One reason is the cause-and-effect relation in PI analysis hasn’t been firmly established in practical applications. For example, with SI analysis, a logic failure can be traced to a noise threshold violation. PI analysis, on the other hand, hardly points out to a smoking gun with the same rigor. Starting from a qualitative and descriptive introduction of power noise fundamentals, the current analysis techniques for printed circuit structures will be reviewed and their limitations will be discussed with practical workarounds. Some recent developments including a novel interpretation of the effective radius of a decoupling capacitor and multipin optimization of capacitors will be presented on sample cases.