Radiated electromagnetic interference (EMI) from switching power supplies is dynamic and situational problem that relates to circuit board layout, component placement and parasitic effects within the power supply itself, as well as the overall system in which it operates. As such, the issue is quite challenging from the system designer’s perspective, and an understanding of radiated EMI measurement requirements, frequency ranges and applicable limits is important.
Having reviewed the relevant standards for conducted EMI in part 1, part 2 of this Power House blog post series provides an overview of radiated EMI standards. Table 1 from part 1 provides a list of relevant abbreviations that are applicable here as well.
EMI standards for automotive
Assessing EMI performance in automotive applications is an issue of increasing concern for end-system designers involved in automotive design and testing. Tracking all possible interactions that might result in a radiated EMI problem is a challenge, particularly given the relatively small volume within a vehicle’s wiring harness characterized by densely packed arrangements of power and signal runs.