Title |
Design and Fabrication of Low-Power, High-Frequency, High-Performance Magnetic Thin Film Transformer |
Authors |
윤의중(Yun, Ui-Jung) ; 정명희(Jeong, Myeong-Hui) |
Keywords |
solenoid-type ; thin-film transformers ; DC-DC converter ; Ni_{81}Fe_{19) core ; Maxwell simulator ; high-frequency |
Abstract |
In this paper, the low power (1.5 W) solenoid-type magnetic thin-film transformers utilizing a Ni_{81}Fe_{19) core material were designed and fabricated for 5 MHz-drive DC-DC converter application. The 20μm thick copper films were used as the coils. The transformers fabricated in this work have the sizes of 3.08 mm×25.5 mm and 6.15 mm×12.75 mm. The optimum design of solenoid-type magnetic thin film transformers was performed utilizing the conventional equations, a Maxwell computer simulator (Ansoft HFSS V7.0 for PC), and parameters obtained from the magnetic properties of NiFe magnetic core materials. frequency characteristics of inductance, dc resistance (R), coupling factor (k) and gain of developed transformers were measured using HP4194A impedance and gain-phase analyzer. The fabricated transformers with the size of 6.15 mm×12.75 mm exhibit the inductance of 0.83 μH, the dc resistance of 2.3ΩΩ, the k of 0.91 and the gain of -1 dB at 5 MHz, which show the comparable results to those reported in the recent literatures. The measured high-frequency characteristics for the fabricated transformers agreed well with those obtained by theoretical calculations . |