TABLE OF CONTENTS In Figure 3.2, we see how the AC, DC, peak-to-peak, and peak values of the inductor current waveform are defined. In particular we note that the AC value of the current waveform is defined as
We should also note from Figure 3.2 that I L ?I DC. Therefore, sometimes in our discussions that follow, we may refer to the DC level of the inductor current as I DC, and sometimes as the average inductor current I L, but they are actually synonymous. In particular, we should not get confused by the subscript " L" in I L. The " L" stands for inductor, not load. The load current is always designated as I O. Of course, we do realize that I L =I O for a buck, but that is just happenstance.
In Figure 3.2 we have also defined another key parameter called r, or the current ripple ratio. This connects the two independent current components I DC and ? I. We will explore this particular parameter in much greater detail a little later. Here, it suffices to mention that r needs to be set to an "optimum" value in any converter, usually around 0.3 to 0.5, regardless of the specific application conditions, the switching...
