inductor design in smps Division of Spang & Company Technical Bulletin BULLETIN SR-1A INDUCTOR DESIGN IN SWITCHING REGULATORS Better efficiency, reduced size, and lower costs have combined to make the switching regulator a viable method for converting unfiltered DC input voltages into regulated DC outputs. This brochure describes the switching regulator and presents design information. In particular, MAGNETICS Ferrite and Molypermalloy Powder cores used for the power inductor are highlighted. DESCRIPTION A typical circuit consists of three parts: transistor switch, diode clamp, and an LC filter. An unregulated DC voltage is applied to the transistor switch which usually operates at a frequency of 1 to 50 kilohertz. When the switch is ON, the input voltage, Ein , is applied to the LC filter, thus causing cu……