Murata Manufacturing Co., Ltd.

Norimichi Onozaki

Mitsuru Odahara

Kaoru Tachibana

An inductor which avoids heat generation and heat dissipation problems, and has a reduced resistance component, when used in a voltage converter. An inductor is configured with a pair of outer electrodes disposed on both end portions of an element assembly and electrically connected to end portions of conductors. The conductors are made of a flat-type wire having a rectangular cross section, are placed side by side between the end portions, and include cylindrical winding sections, respectively, in which the flat-type wire in a long side direction of the rectangular cross section is wound the number of turns less than one about a thickness direction intersecting with a length direction connecting the pair of end portions along the thickness direction. A heat-dissipating member includes a portion being a partition between the conductors and a portion exposed on the top of an outer surface of the element assembly.

Inductor and voltage converter using it

A voltage converter with which energy conversion efficiency can be improved during not only low-load conditions but also high-load conditions. A step-down DC-DC converter includes a tapped inductor and a capacitor. The inductor and the capacitor form an LC filter. The inductor and a switching element form a variable inductor having a changeable inductance value. The capacitor and a variable DC voltage source form a variable capacitor having a changeable capacitance value. A control unit changes the inductance value of the variable inductor in accordance with an input/output voltage ratio Vin/Vout between a DC input voltage and a DC output voltage. The control unit changes the capacitance value of the variable capacitor to a capacitance value with which an LC resonant frequency is maintained constant when changing the inductance value of the variable inductor.

Voltage converter

An electronic component includes a multilayer body having a configuration, in which a plurality of insulator layers containing ferrite ceramic are stacked, and a coil having a configuration, in which a plurality of coil conductor layers containing Ag and being disposed on the insulator layers are connected to at least one via hole conductor penetrating the insulator layers in the stacking direction, and having a spiral shape spiraling in the stacking direction. A first pore area ratio of a side gap interposed between an outer circumferential edge of an annular track formed by stacking the plurality of coil conductor layers and an outer edge of the multilayer body, when viewed in the stacking direction, is 9.0% or more and 20.0% or less, and the second pore area ratio of a portion interposed between two coil conductor layers in the stacking direction is 8.0% or less.

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Nagaokakyo, Japan

Norimichi Onozaki