An object of the present invention is to provide a power converter capable of preventing upsizing of a chip on which a switching element is formed and detecting the temperature in a switching operation of the switching element. A power converter includes: an IGBT connected between an IGBT connected to the positive electrode side of a variable power supply and the negative electrode side of the variable power supply; a temperature detection resistor element connected to a gate to which a gate signal for controlling the switching operation of the IGBT is input and detecting the temperature of the IGBT; and a detector detecting the temperature level of the IGBT based on the voltage of the gate.

A drive circuit is provided. When the switching element is in turn-on state and a collector-emitter voltage of the switching element is equal to or higher than a first predetermined voltage value, the first diode is turned on; the first transistor and the second transistor are turned on; and, after a mask time in which a first capacitor is started to be charged with a current from a current source and a voltage value at two ends becomes equal to or higher than a second predetermined voltage value higher than the first predetermined voltage value, an abnormality detection signal is output to the control unit. The control unit stops an output of the pulse signal to the switching element in response to the abnormality detection signal.

A semiconductor device of embodiments includes: a semiconductor layer including a first trench, a second trench, a first semiconductor region of a first conductive type, a second semiconductor region of a second conductive type provided between a first face and the first semiconductor region, between the first trench and the second trench, and in contact with the second trench, a third semiconductor region of a first conductive type provided between the first trench and the second semiconductor region, a fourth semiconductor region of a second conductive type provided between the third semiconductor region and the first face, and a fifth semiconductor region of a second conductive type provided between the second semiconductor region and the first face, spaced from the fourth semiconductor region, in contact with the second trench; a first electrode on a first face side; and a second electrode on a second face side.

A voltage-controlled switching device includes a drain/drift structure formed in a semiconductor portion with a lateral cross-sectional area A.sub.Q, a source/emitter terminal, and an emitter channel region between the drain/drift structure and the source/emitter terminal. A resistive path electrically connects the source/emitter terminal and the emitter channel region. The resistive path has an electrical resistance of at least 0.1 mΩ*cm.sup.2/A.sub.Q.

The disclosed technology relates to a gate protection circuit for an Insulated Gate Bipolar Transistor (IGBT), the IGBT being used as a switch device in a solid state pulse modulator based on the MARX generator principle, the gate protection circuit including: a voltage regulator configured to supply a stable voltage to an emitter of the IGBT with respect to the ground for a gate of the IGBT.

An alternating current solid-state relay having a short-circuit protection function, comprises an output switch circuit, which is connected to a load loop in series and comprises two power switch transistors, a driver circuit having a short-circuit protection function, and a short-circuit detection circuit, wherein the two power switch transistors are IGBTs or MOS transistors and are in opposing series, and two terminals formed after series connection of the two power switch transistors serve as two output terminals of the alternating current solid-state relay; a power circuit supplies power to the driver circuit, and the driver circuit correspondingly controls on-off of the two power switch transistors according to a control signal accessed to an input terminal of the driver circuit, and detects through the short-circuit detection circuit whether or not a short circuit happens to a load; and if yes, the two power switch transistors are controlled to be turned off.

In a level shifter circuit that transmits a set signal and a reset signal input to input terminals of a high-side latch circuit, the source sides of high voltage transistors are connected to current negative feedback resistors, and transistors are connected in parallel to the current negative feedback resistors. Further included is a high-side voltage detection circuit that detects whether the voltage of a high-side power supply terminal is a high voltage. When a high voltage is detected, the transistors are turned OFF to make the drain currents that flow smaller, thereby making it possible to improve the trade-off between heat generation and propagation delay characteristics in the high voltage transistors.

To provide a technique to complement overcurrent protection and short circuit protection. An LVIC includes an overcurrent detector configured to detect whether or not a first current flowing through a load and a semiconductor switching element is abnormal and a short-circuit detector configured to detect whether or not a second current flowing not through the load but through the semiconductor switching element is abnormal. The LVIC interrupts the semiconductor switching element based on a detection result of the overcurrent detector and a detection result of the short-circuit detector.

A gate driver circuit receiving an input control signal and providing a voltage at a gate terminal of a semiconductor switching device (e.g., an IGBT) may include: (i) a first voltage source providing a first voltage; (ii) a second voltage source providing a second voltage, wherein the first voltage is higher than the second voltage; and (iii) a selector circuit selecting, based on the input control signal's logic state, either the first voltage or the second voltage to be placed on the gate terminal of the semiconductor switching device.

A method for operating an IGBT includes determining a maximum stationary reverse bias required for operation of the IGBT, determining a first removal charge, the removal of which at the gate of the IGBT causes an electric field strength that enables the IGBT to accept the maximum stationary reverse bias during stationary blocking, determining a second removal charge, the removal of which at the gate causes an electric field strength that leads to a dynamic avalanche, and, when the IGBT is switched off, removing from the gate during a charge removal duration a removal charge that is greater than the first removal charge and smaller than the second removal charge.