JAJU633 October 2018
The inductor value is calculated to ensure the circuit operates in continuous conduction mode (CCM) for a certain range of output currents at the typical operating points. In this design, the CCM to DCM boundary is set to about 1/3 of the maximum output power of 55 W, or a 1.25 A LED current with a 44 V LED load. As a result, this power boundary (PO(BDRY)) is set for 18 W and the inductor values can be calculated using Equation 5 for the boost regulator:
where
A value of 22 µH is selected for L2.