| 摘要 |
In a DC-DC converter, a semiconductor integrated circuit component including a switching element and a control circuit is mounted on a soft magnetic multilayer substrate having a laminated coil wherein a plurality of conductor wires are connected. The semiconductor integrated circuit component is provided with an input terminal, an output terminal a first control terminal for controlling on/off of the switching element, a second control terminal for variably controlling an output voltage, and a plurality of grounding terminals. The soft magnetic multilayer substrate is provided with a first external terminal formed on a first main plane, a first connecting wiring formed on the first main plane and/or on an inner layer in the vicinity of the first main plane, a second connecting wiring formed between a side plane of the multilayer substrate and an outer circumference of the laminated coil, and a second external terminal formed on a second main plane. A terminal of the semiconductor integrated circuit component is connected to a first external terminal of the multilayer substrate, and at least a part of the first external terminal is electrically connected with a second external terminal through the first connecting wiring and the second connecting wiring, and the input terminal or the output terminal is connected to the second external terminal through the lamianted coil. |
