A change rate control circuit computes a first drive speed, which is a gate drive speed of a gate of a drive-subject element, for controlling a change rate of an element voltage of the drive-subject element at a target change rate during a change period. A timing generating circuit acquires, in advance, a delay time caused when the gate is driven and determines a switching timing, at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-off of the drive-subject element and generates a timing signal representing the switching timing. A speed change circuit changes the gate drive speed from the first drive speed to a second drive speed at the switching timing during turn-off of the drive-subject element.

A switched emitter follower circuit is constituted by a transistor in which a base is connected to a signal input terminal, a power voltage is applied to a collector, and an emitter is connected to a signal output terminal, a capacitor in which one end is connected to the collector of the transistor, and the other end is connected to the emitter of the transistor, and a Gilbert-cell type multiplication circuit in which a positive-phase clock output terminal is connected to the emitter of the transistor, a negative-phase clock output terminal is connected to the base of the transistor, and a multiplication result of a differential clock signal and a differential clock signal input from an outside is output to the positive-phase clock output terminal and the negative-phase clock output terminal.

A control device for connecting between two portions of an electrical power supply line. The device includes a bipolar transistor including a wide bandgap semiconductor material and having its emitter connected to one portion of the power supply line, its collector connected to another portion of the power supply line, and the device also including control connected to the base of the transistor.

A switched emitter follower circuit is constituted by a transistor in which a base is connected to a signal input terminal, a power voltage is applied to a collector, and an emitter is connected to a signal output terminal, a capacitor in which one end is connected to the collector of the transistor, and the other end is connected to the emitter of the transistor, and a Gilbert-cell type multiplication circuit in which a positive-phase clock output terminal is connected to the emitter of the transistor, a negative-phase clock output terminal is connected to the base of the transistor, and a multiplication result of a differential clock signal and a differential clock signal input from an outside is output to the positive-phase clock output terminal and the negative-phase clock output terminal.

A circuit for improving the switching speed of a power electronic switching chip and application thereof are provided. The design method of improving the switching speed of the power electronic switching chip is to switch its state in the saturated conductive state to the simulated saturated-high-on-voltage state which is much higher than the traditional low-saturated-on-voltage state. In this way, the carrier density in the base region and the trailing time constant are greatly reduced and the total power consumption of trailing in the cut-off period can be greatly reduced, and the design limit of switching speed can be improved and the service reliability can be achieved. Therefrom, a design method for power supply of high frequency power electronic transformer (converter) is further disclosed.

The disclosure relates to a switch arrangement for a converter, comprises: a first series connection of at least two switches between two terminals of the switch arrangement, wherein the two switches are semiconductor switches; a second series connection of a first capacitor and a first diode circuit electrically connected in parallel to first part of the first series connection between a first terminal of the two terminals and node between the two switches, wherein the first diode circuit comprises at least one diode; and third series connection of a second capacitor and a second diode circuit electrically connected in parallel to a second part of the first series connection between second terminal of the two terminals and the node between the two switches, wherein the second diode circuit comprises at least one diode. Further a method for switching such a switch arrangement between the conducting state and the non-conducting state.

A gate drive circuit is used in a dynamic characteristic test on a power semiconductor, the gate drive circuit includes a voltage source configured to change a gate voltage of a gate of the power semiconductor, a plurality of resistance setting circuits connected in parallel with the voltage source and the gate, and a switching circuit connecting at least one resistance setting circuit of the resistance setting circuits to the voltage source and the gate.

A method is provided for operating a semiconductor device which includes an IGBT having a desaturation semiconductor structure connected to a first electrode terminal and a gate electrode terminal for controlling a desaturation channel. The method includes: applying a first gate voltage to the gate electrode terminal so that current flows through the IGBT between the first electrode terminal and a second electrode terminal and current flow through the desaturation channel is substantially blocked; applying a different second gate voltage to the gate electrode terminal so that current flows through the IGBT between the first and second electrode terminals and charge carriers flow as a desaturating current through the desaturation channel to the first electrode terminal; and applying a different third gate voltage to the gate electrode terminal so that current flow through the IGBT between the first and second electrode terminals is substantially blocked.

A change rate control circuit computes a first drive speed, which is a gate drive speed of a gate of a drive-subject element, for controlling a change rate of an element voltage of the drive-subject element at a target change rate during a change period. A timing generating circuit acquires, in advance, a delay time caused when the gate is driven and determines a switching timing, at which the element voltage reaches a switching threshold voltage which is lower than a desired switching voltage by a predetermined value, during turn-off of the drive-subject element and generates a timing signal representing the switching timing. A speed change circuit changes the gate drive speed from the first drive speed to a second drive speed at the switching timing during turn-off of the drive-subject element.

A method is provided for operating a semiconductor device which includes an IGBT having a desaturation semiconductor structure connected to a first electrode terminal and a gate electrode terminal for controlling a desaturation channel. The method includes: applying a first gate voltage to the gate electrode terminal so that current flows through the IGBT between the first electrode terminal and a second electrode terminal and current flow through the desaturation channel is substantially blocked; applying a different second gate voltage to the gate electrode terminal so that current flows through the IGBT between the first and second electrode terminals and charge carriers flow as a desaturating current through the desaturation channel to the first electrode terminal; and applying a different third gate voltage to the gate electrode terminal so that current flow through the IGBT between the first and second electrode terminals is substantially blocked.