Relating r to the Inductance

We know that current swing is voltseconds per unit inductance. So we can also write 

Here Et is defined as the (magnitude of the) volt/aseconds across the inductor (either during the on-time or off-time — both being necessarily equal in steady state), and L h is the inductance in pH. The reason for defining Et is that this number is simply easier to 

Note also that from now on, whenever L is paired up with Et in any given equation, we will drop the subscript of L, that is, pH. It will then be understood that L is in pH. 

Incidentally, the preceding equation, that is, the one involving Voff, assumes CCM, because it assumes that toFF (the time for which Voff is applied) is equal to the full available off-time (1 — D)/f. 

In subsequent sections we will often use the following easy-to-remember form of the previous equations. We are going to nickname this the L x I equation (or rule) 

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