Fuji Electric Co., Ltd.

Fuji Electric Device Technology Co., Ltd.

Naotaka Matsuda

Naoki Kumagai

Susumu Iwamoto

Seiki Igarashi

Kazunori Oyabe

Hideaki Kakiki

A semiconductor device of the present invention suppresses high frequency noise caused in a semiconductor device incorporating SiC elements. The semiconductor device includes semiconductor elements connected in series, a SiC diode element connected in parallel to the semiconductor element, and an oscillation suppressing circuit being connected in parallel to the semiconductor element and the SiC diode element and suppressing voltage fluctuation caused in the SiC diode element in response to turn-ons of the semiconductor element. The oscillation suppressing circuit suppresses voltage fluctuation caused in the SiC diode element in response to turn-ons of the semiconductor element thereby improving reliability of the semiconductor device.

Semiconductor device and oscillation suppressing device

A switching power supply includes: a transformer having a primary coil and a secondary coil; a switching element that is connected in series to the primary coil of the transformer so as to turn a direct-current input voltage applied to the primary coil of the transformer ON and OFF; a rectifying and smoothing circuit that rectifies a voltage induced in the secondary coil of the transformer to generate a direct-current output voltage; and a control circuit that turns the switching element ON and OFF in accordance with the direct-current output voltage, wherein the control circuit includes an input correction circuit that detects a switching period of the switching element and limits a peak value of a current flowing through the switching element in accordance with the detected switching period.

Switching power supply with peak current limiter

An intelligent power module includes semiconductor switching devices, drive circuits, a variety of detecting circuits and warning circuits for detecting a fatal abnormal condition and a precursory abnormal condition thereof in the switching devices, the drive circuits and so forth, abnormal condition detecting logic devices and drive circuits for protecting the switching devices when the detecting circuits and the warning circuits detect the abnormal condition, and control circuits and a transmission circuit for outputting a signal based on detection of the abnormal condition. The transmission circuit has an output terminal for outputting alarm signals when the fatal abnormal condition is detected, and an output terminal for outputting abnormality factor discrimination signals indicating abnormality factors contributing to the fatal abnormal condition and the precursory abnormal condition.

Intelligent power module

A power semiconductor module that automatically sets an optimum dead time without being affected by the switching characteristics or driving mode of individual power semiconductor devices. The power semiconductor module includes a pair of IGBTs disposed in an upper and lower arm, respectively, and driving circuits for driving IGBTs. The power semiconductor module includes current detecting circuits and zero current detecting circuits for detecting that the output current of each of the IGBTs has become nearly zero, an inverting circuit, upper arm driving circuit and lower arm driving circuit for generating actual driving signals for each IGBT, using the output signals of the zero current detecting unit and ON commands for the IGBTs of the other arms.

Growing community of inventors

Nagano, Japan

Naotaka Matsuda