Fuji Electric Co., Ltd.

Fuji Electric Device Technology Co., Ltd.

Fuji Electric Systems Co. Ltd.

Kazunori Oyabe

Tatsuhiko Fujihira

Kazuhiko Yoshida

Akira Nakamori

Yukio Yano

Naoki Kumagai

Shoichi Furuhata

Yasushi Miyasaka

Tomoyuki Yamazaki

Manabu Watanabe

Shin Kiuchi

Naotaka Matsuda

Tetsuhiro Morimoto

A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.

Inverter driving circuit an inverter control circuit

A drive circuit for an insulated gate device includes a constant current source generating a constant current, and a switching circuit, wherein a gate of the insulated gate device is connected to a power supply potential side via the constant current source at the time of turn-on and to a ground potential side at the time of turn-off. Whereby a drive circuit for the insulated gate device can be reduced loss at the time of turn-on and reduced temperature dependency of noise.

Drive circuit for insulated gate device

A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.

Temperature measurement device of power semiconductor device

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

When an alarm signal provided by an inverter forming an I/F provided for the circuit on the high side enters an active (L) state, the output of the inverter indicates an H state. Then, the N-channel MOS type FET enters an ON state. At this time, the N-channel MOS type FET is connected to the I/F on the low side using a diode. Therefore, when the diode enters a normal bias state, that is, when the reference potential of the above mentioned two I/Fs approach each other, an electric current flows from the power supply to the N-channel MOS type FET through a resistor. As a result, by a voltage drop, a voltage arises in the resistor, and the output of the inverter indicates the H state. Since the output of the inverter is connected to a control unit, the control unit performs a process according to an alarm signal. Thus, the electric power conversion apparatus having a circuit on a low side for performing a switching operation based on reference potential and a circuit on a high side for performing a switching operation based on floating reference potential which is different from the reference potential by a variable amount can be smaller and less costly.

Electric power conversion apparatus

A gate drive circuit device for a voltage-driven semiconductor element reduces the time to dissipate inductively stored electromagnetic energy and reduces current consumption by using cyclically charged capacitative storage to produce a control signal that is about twice the supply voltage. This permits full-ON dissipation of the stored energy after the circuit cuts off power to the inductive element. In one embodiment, the dissipation is chiefly in a voltage-regulator diode connected to limit the voltage appearing across a transistor. In another embodiment, a voltage regulator diode permits a transistor to operate in the full-on condition, while limiting the voltage across it to a value below its withstand voltage, whereby a maximum power dissipation current flows in the transistor. In a further embodiment a gate drive signal generator eliminates a voltage regulator diode from the conventional gate drive circuit device. Instead, this embodiment substitutes switching devices both on the power supply side and the reference potential (ground) side. Both switching devices include a switch and an operating section that controls switching operation. The two operating sections receive an externally generated command signal for timing the ON/OFF operation of the switches. The control technique permits both the switching and operating sections to be fabricated integrally as an integrated circuit.

Gate drive circuit having reduced current-consumption and rapid

The disclosed invention is designed to prevent the oscillation which often occurs in an over-current protection apparatus for an insulated gate controlled transistor. The apparatus improves the response in current detection, to prevent oscillation, and improves protection speed against over-current. This is accomplished by separating the gates of the main transistor and the current detector transistor; by setting a shorter time constant for the gate circuit of the current detector transistor than that of the gate circuit of the main transistor; by feeding the detection signal obtained from the current detecting means which detects the current i of the current detector transistor proportional to the current I flowing through the main transistor, to the control means; and by controlling the gate potentials of both transistors to protect the main transistor from the over-current by feeding the comparison output Sd from the comparator circuit, which compares the voltage of the signal Vd with the reference voltage Vr, to the control circuit.

Over-current protection apparatus for transistor

A constant current circuit of the invention supplies a constant current to a load. The constant current circuit is formed of a current source device for providing an input current having a predetermined value with temperature dependence, a voltage divider device connected to the current source device, and an output transistor device. A reference transistor device or an adjusting transistor device is attached to the current source device. In case the reference transistor device is used, the voltage divider device divides a reference voltage of the reference transistor device to thereby generate a control voltage. In case the adjusting transistor device is used, an adjusting voltage from the voltage divider device is supplied to the adjusting transistor device to generate a control voltage. The output transistor device is connected to the load for controlling an output current supplied to the load in response to the control voltage. Temperature dependence of the output current is adjusted by setting voltage dividing ratio of the voltage divider device.

Growing community of inventors

Nagano, Japan

Kazunori Oyabe