Understanding & Optimizing EMC...

Understanding & Optimizing EMC in SMPSUnderstanding and Optimizing Electromagnetic Compatibility in Switchmode Power Supplies
Bob Mammano and Bruce Carsten
ABSTRACT Electromagnetic noise issues have long been a concern with switching power supplies, as their highfrequency switching of voltage and current generate higher order harmonics that have the potential to cause interference with system operation. While international specifications and standardized testing procedures have at least provided a greater understanding of the problems, optimum solutions must still come from techniques that are applied during the design process. This topic attempts to describe the more significant causes of EMI in power supplies and offer design techniques to minimize their impact.

I. INTRODUCTION While switchmode power supplies are well known