A speed-up circuit is configured to be provided between a power supply terminal and a gate of a semiconductor switching element. An impedance element is configured to be provided between a signal input terminal and a node, the node being between the speed-up circuit and the gate of the semiconductor switching element. In the speed-up circuit, a second field effect transistor is connected in series to a first field effect transistor and is configured to be connected to the gate of the semiconductor switching element. The impedance element has an impedance higher than an impedance of the speed-up circuit when both the first field effect transistor and the second field effect transistor are in an ON state.

A switch circuit includes a control unit, a driving unit, a voltage sudden-change unit, and a connection unit. The connection unit is configured to turn on or turn off an electrical connection between a power-supply device and a load. The control unit is configured to control the driving unit to output or stop outputting a driving signal to the connection unit, where the driving signal allows to turn on the connection unit. The voltage sudden-change unit is coupled with a driving node between the driving unit and the connection unit. The control unit is configured to control the voltage sudden-change unit to output a voltage sudden-change signal to the driving node, where the voltage sudden-change signal allows to make the connection unit be switched to a turned-off state from a turned-on state quickly when the driving unit stops outputting the driving signal.

A switch circuit includes a control unit, a driving unit, a voltage sudden-change unit, and a connection unit. The connection unit is configured to turn on or turn off an electrical connection between a power-supply device and a load. The control unit is configured to control the driving unit to output or stop outputting a driving signal to the connection unit, where the driving signal allows to turn on the connection unit. The voltage sudden-change unit is coupled with a driving node between the driving unit and the connection unit. The control unit is configured to control the voltage sudden-change unit to output a voltage sudden-change signal to the driving node, where the voltage sudden-change signal allows to make the connection unit be switched to a turned-off state from a turned-on state quickly when the driving unit stops outputting the driving signal.

A high frequency switch configured to switch paths of differential signals arranged in an integrated circuit. The high frequency switch includes a pair of pole terminals and a plurality of pairs of throw terminals. The pair of pole terminals constitutes one port. Each pair of throw terminals constitutes another port.

A method and apparatus is disclosed for maintaining a stable power supply to a circuit when activating/deactivating a switch in order to accelerate the switching time of the switch. The gate of a FET is coupled to a switch driver. The switch driver is powered by a positive power supply and a negative power supply. When the switch is to be activated/deactivated, the gate is first coupled to a reference potential (i.e., ground) for a “reset period” to reduce any positive/negative charge that has been accumulated in the FET. At the end of the reset period, the gate is then released from the reference potential and the switch driver drives the gate to the desired voltage level to either activate or deactivate the switch.

The present invention provides a drive device and a power supply system capable of driving a power transistor with low power while reflecting variations in manufacture process and external environments. A trigger detection circuit monitors a voltage between terminals or a current between terminals in a switching period of a power transistor and detects that the voltage between terminals or the current between terminals reaches a predetermined reference value. A current switching circuit selects a register outputting a current value to a variable current driver circuit from a plurality of registers and switches the register to be selected using a detection result of the trigger detection circuit as a trigger in the switching period, thereby making the drive current of the variable current driver circuit shift.

A thyristor switch is constituted of a pair of arms connected in anti-parallel, each of the anus including a plurality of thyristors connected in series. A controller includes a phase detecting unit configured to detect a phase of a power supply voltage supplied from an alternating-current power supply, and a gate signal generating unit configured to interrupt a gate signal when an open command is provided to the static switch and the phase of the power supply voltage detected by the phase detecting unit matches a target phase. The target phase is set outside of a phase range where interruption of the gate signal is prohibited, the phase range being set so as to include a zero crossing point at which a load current is switched in polarity.

In one aspect, a solid-state switching apparatus is provided that includes a pair of anti-parallel thyristors, a quasi-resonant turn-off circuit, a sensor, and a control circuit. The turn-off circuit is coupled in parallel with the pair of anti-parallel thyristors and includes a first selectively conductive path and a second selectively conductive path. The sensor is configured to sense a thyristor current conducted by at least one of the pair of anti-parallel thyristors. The control circuit is configured to receive the sensed thyristor current from the sensor and determine a magnitude of the sensed thyristor current and a polarity of the sensed thyristor current. The control circuit is further configured to activate, in response to determining that the magnitude is greater than a threshold value, one of the first selectively conductive path and the second selectively conductive path based on the polarity to commutate and interrupt the thyristor current.

Routing of a gate signal for controlling a discrete power switching device (such as in an inverter for an electric vehicle drive) is configured to compensate for the common source inductance inherent in the switching device as a result of its integrated circuit packaging. The power device has a gate signal path via a gate pin and a power signal path via first and second power pins, wherein the gate signal path and the power signal path have a first mutual inductance. A circuit board apparatus provides a gate wiring loop juxtaposed with the power signal path, wherein the gate wiring loop and the power signal path have a second mutual inductance substantially canceling the first mutual inductance. The resulting reduction in common source inductance avoids the reductions in switching speed and the increased switching losses otherwise introduced by the common source inductance.

An electric assembly includes a bipolar switching device and a transistor circuit. The transistor circuit is electrically connected in parallel with the bipolar switching device and includes a normally-on wide bandgap transistor.