Overview

The reader is strongly advised to read Chapter 1 before attempting this chapter.

The magnetic components of any switching power supply are an integral part of its topology. The design and/or selection of the magnetics can affect the selection and cost of all the other associated power components, besides dictating the overall performance and size of the converter itself. Therefore, we really should not try to design a converter, without looking closely at its magnetics, and vice versa. With that in mind, in this chapter, we will be introducing the basic concepts of magnetics in parallel with a formal dc-dc converter design procedure.

Note that in the area of dc-dc converters, we have only a single magnetic component to consider its inductor. Further, in this particular area of power conversion, it is customary to just pick an off-the-shelf inductor for most applications. Of course there cannot possibly be enough "standard" inductors going around to cover all possible application scenarios. But the good news is that, given a certain inductor, and knowing its performance under a stated set of conditions, we can easily calculate how it will perform under our specific application conditions. And thereby, we can either validate or invalidate our initial selection. It may take more than one iteration or attempt, but moving in this direction, we can almost always find a standard inductor that fits our application.

In the next chapter we will take up "off-line" power supply design. Such...