FeCoBN Magnetic Thin Film Inductor for MHz Switching Micro DC-DC Converters

Abstract

In order to obtain higher efficiency of the micro switching dc-dc converter using thin film magnetic device, FeCoBN magnetic film for thin film inductor was newly developed, which had high saturation magnetization of about 1.7 T, and high electrical resistivity over 3μ Ω m. Consequently, a newly fabricated magnetic thin film inductor using the FeCoBN magnetic film had lower power loss due to the small eddy current loss. 5 MHz switching buck and boost converters using the new thin film inductor had higher efficiencies than those of the conventional micro switching dc-dc converters. © 2001, The Institute of Electrical Engineers of Japan. All rights reserved.