Title :
Characteristics of magnetic thin-film inductors at large magnetic field
Author :
Tramaguchi, M. ; Okuyama, H. ; Arai, K.I.
Author_Institution :
Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan
fDate :
11/1/1995 12:00:00 AM
Abstract :
The authors have developed an instrument to measure the impedance of thin-film cores in the 1 MHz-30 MHz range up to 300 mA. The relation between the applied field intensity and the electric characteristics of magnetic thin-film inductors made of NiFeCuMo films and Cu films were examined by the instrument. Electric characteristics of the closed magnetic-circuit type inductor were influenced much by the dc properties of the magnetic film even at high frequencies. The open magnetic-circuit type inductor was less influenced by the dc magnetic properties because of the reluctance of the air gaps. The temperature increase corresponded to the measured large signal resistances quantitatively, If the rated current is 50 mA and the allowable temperature is 59°C, the resistance at the operating frequency must be less than 4 Ω
Keywords :
air gaps; copper; copper alloys; electric impedance; ferromagnetic materials; inductors; iron alloys; magnetic cores; magnetic thin film devices; molybdenum alloys; nickel alloys; soft magnetic materials; 1 to 30 MHz; 300 mA; 4 ohm; 50 C; 500 mA; Cu films; NiFeCuMo films; NiFeCuMo-Cu; air gap reluctance; applied field intensity; closed magnetic-circuit type inductor; dc magnetic properties; dc properties; electric characteristics; high frequencies; impedance; large magnetic field; magnetic thin-film inductors; open magnetic-circuit type inductor; thin-film cores; Electric variables; Frequency; Impedance measurement; Instruments; Magnetic field measurement; Magnetic films; Magnetic properties; Temperature; Thin film inductors; Transistors;
Journal_Title :
Magnetics, IEEE Transactions on
