Characterizing an Off-the-shelf Inductor in a Specific Application

Worked Example (6) — Characterizing an Off-the-shelf Inductor in a Specific Application 

The procedure will be illustrated by means of a step-by-step worked example. Though it is carried out for a buck, throughout the calculation, we will indicate precisely how the procedure and equations may need to change, were this a boost or a buck-boost. So for example, to the right of any equation presented below, we have indicated in brackets, which topology it is valid for. 

Material (Vendor) Grade C p(BP) d(fd) n w bSAT (gauss) w f V1AX (MHz) 

As mentioned, all the steps involved in the general inductor design procedure below are being carried out at a certain Vin — which is the maximum input voltage for a buck, and minimum input voltage for a boost or a buck-boost. 

For a buck regulator, the duty cycle is (now including the switch and diode forward drops) 

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