Title :
High-frequency operation of a planar-type microtransformer and its application to multilayered switching regulators
Author :
Yamasawa, Kiyohito ; Maruyama, Kenji ; Hirohama, Isao ; Biringer, Paul P.
Author_Institution :
Dept. of Electr. & Electron. Eng., Shinshu Univ., Najano, Japan
fDate :
5/1/1990 12:00:00 AM
Abstract :
The operation of a multilayered microtransformer composed of planar zig-zag coils and amorphous magnetic film is described. The transformer has a maximum efficiency of 77.5%. Its equivalent circuit is approximated by the parallel connection of the winding inductance and of the stray capacitance. Variable magnetic coupling is obtained between the primary and secondary windings by shifting the relative position of the two coils. The microtransformer is used in a magnetically controlled multilayered switching regulator. The regulator has an output of 1.4 W and an efficiency of 24%. The magnetization loss in the circuit is the same as that of the semiconductors. A two-output-type multilayered switching regulator is also proposed that has an acceptably good output characteristic at each port even though a common magnetic film is used
Keywords :
high-frequency transformers; switched mode power supplies; 1.4 W; SMPS; amorphous magnetic film; common magnetic film; equivalent circuit; high-frequency operation; magnetization loss; maximum efficiency; multilayered switching regulators; output characteristic; parallel connection; planar-type microtransformer; relative position; stray capacitance; two-output-type; variable magnetic coupling; winding inductance; zig-zag coils; Amorphous magnetic materials; Amorphous materials; Capacitance; Coils; Coupling circuits; Equivalent circuits; Inductance; Magnetic films; Magnetic switching; Regulators;
Journal_Title :
Magnetics, IEEE Transactions on
