Abstract: In a base region of a first conductivity type, at least one emitter region of a second conductivity type and at least one sense region of the second conductivity type, spaced away from the emitter region, are selectively formed. The emitter region and the sense region are located so as to be aligned in a second direction perpendicular to a first direction going from a collector region of the first conductivity type, which is formed so as to be spaced away from the base region, toward the base region. The width of the sense region, the width of the emitter region, the width of a part of the base region that is adjacent to the sense region, and the width of a part of the base region that is adjacent to the emitter region in the second direction are set in such a manner that a sense ratio varies in a desired manner in accordance with variation in collector current.

Abstract: The present invention includes a voltage clamping circuit 6 for outputting a voltage signal, which has been clamped to a predetermined voltage, from the drain voltage of a switching element 1, and a turn-on detection circuit 7 for detecting the turn-on timing of the switching element 1 from the voltage signal. Thus it is possible to turn on the switching element 1 at the minimum value of the drain voltage without adding external terminals.

Abstract: A driving circuit according to the present invention is a driving circuit which drives the voltage control type switching device in the switching power supply apparatus and includes: a generation unit configured to generate a driving signal for turning on and off the voltage control type switching device, the driving signal having plural levels of voltage at which the voltage control type switching device is turned on; and a switching control unit configured to switch between the plural levels of voltage at which the power switching device is turned on, depending on a status of the power switching device.

Abstract: In a high-voltage semiconductor switching element, in addition to a first emitter region that is necessary for switching operations, a second emitter region, which is electrically connected with the first emitter region through a detection resistor in current detection means and is electrically connected with the current detection means, is formed. No emitter electrode is formed on the second emitter region, while an emitter electrode is formed on a part of a base region that is adjacent to the second emitter region.

Abstract: In a base region of a first conductivity type, at least one emitter region of a second conductivity type and at least one sense region of the second conductivity type, spaced away from the emitter region, are selectively formed. The emitter region and the sense region are located so as to be aligned in a second direction perpendicular to a first direction going from a collector region of the first conductivity type, which is formed so as to be spaced away from the base region, toward the base region. The width of the sense region, the width of the emitter region, the width of a part of the base region that is adjacent to the sense region, and the width of a part of the base region that is adjacent to the emitter region in the second direction are set in such a manner that a sense ratio varies in a desired manner in accordance with variation in collector current.

Abstract: A borate-based crystal excellent in uniformity and reliability, which is useful as an optical wavelength conversion device, etc., and can be easily produced at low cost in a short period of time, by the steps of dissolving water-soluble starting materials in water to prepare an aqueous solution, evaporating water in the aqueous solution followed by sintering or evaporating the water and not sintering, thereby forming a crystal growth material, and melting the resultant material to grow a crystal. Further, a highly reliable laser oscillation apparatus can be achieved by using this crystal as an optical wavelength conversion device.