Switching Power Supplies A - Z, 2nd Edition

Chapter 17

Fixing EMI Across the Board and Input Filter Instability

This chapter is a broad sweep of the most practical ways of EMI mitigation on the board. The ground plane, the flux band, cancellation windings, beads, and so on are all covered. Filters for dc–dc converters (modules) are also discussed, and the phenomenon of input instability, based on Middlebrook’s extra-element theorem, is mathematically and graphically analyzed in a very simplified manner.

Part 1: Practical Techniques for EMI Mitigation

Here we first look at some of the practical design aspects involved in controlling EMI. These supplement the basic PCB layout guidelines presented in Chapter 10. We first emphasize one aspect of that chapter: that the most potent and cost-effective ...