A gate driver includes a variable strength driver circuit that provides an output signal to drive a high power device. The gate driver receives an update request from a host controller during an operating mode in which switching operations occur and updates one or more operating parameters associated with driving the high power device. The operating parameters including turn-on parameters, turn-off parameters, and soft shutdown parameters. The variable strength driver circuit uses the turn-on parameters for turn-on phases for the output signal, uses the turn-off parameters for turn-off phases for the output signal, and uses the soft shutdown parameters for soft shutdown phases for the output signal. The update request adjusts current, voltage, and/or time for one or more phases of the turn-on, turn-off and/or soft shutdown parameters.

A wiring of a semiconductor switch having a gate, a collector or a drain, and an emitter or a source, includes a first arrangement having a first capacitor connected in series with a parallel connection having a first resistor and a first diode. The first arrangement is connected between the gate and the collector or drain, wherein the first diode is connected away from the gate in a flow direction. A second arrangement is connected in parallel with the first arrangement and includes a second capacitor connected in series with a parallel connection having a second resistor and a second diode, wherein the second diode lies toward the gate in the flow direction.

An over-current protection circuit for composite transistor devices is provided, connected between an input terminal and a load, and including: a control-terminal voltage-generation module whose output voltage varies with its input voltage when driven by a first voltage, wherein the output voltage of the control-terminal voltage-generation module serves as a control-terminal voltage; a composite transistor device, connected between the control-terminal voltage-generation module and the load, configured to conduct in response to the control-terminal voltage and a second voltage to generate an output current flowing through the load; and an over-current protection module, connected between the composite transistor device and the load, wherein when the output current of the composite transistor device exceeds a preset limit, a clamping voltage is applied to the composite transistor device by the over-current protection module to limit a current flowing through the composite transistor device, thereby limiting the output current of the composite transistor device.

A load control device for controlling power delivered from an alternating-current power source to an electrical load may comprise a controllably conductive device, a control circuit, and an overcurrent protection circuit that is configured to be disabled when the controllably conductive device is non-conductive. The control circuit may be configured to control the controllably conductive device to be non-conductive at the beginning of each half-cycle of the AC power source and to render the controllably conductive device conductive at a firing time during each half-cycle (e.g., using a forward phase-control dimming technique). The overcurrent protection circuit may be configured to render the controllably conductive device non-conductive in the event of an overcurrent condition in the controllably conductive device. The overcurrent protection circuit may be disabled when the controllably conductive device is non-conductive and enabled after the firing time when the controllably conductive device is rendered conductive during each half-cycle.

A power supply output device converts an input from a DC-DC converter into a bipolar voltage output of a gate driver circuit driving a power switch. The power output supply device includes an adjusting circuit to measure an output of the gate driver circuit at the gate of the power switch, and to adjust the bipolar voltage output in order to maintain the output of the gate driver circuit at a predetermined voltage. The power supply output device provides a cost-effective technique to regulate the peak positive voltage input into the gate of the power switch at a required voltage, regardless of any fluctuations or losses.

A DC voltage switch includes a semiconductor-based electronically controllable switching device, a sensor provided upstream of the switching device for determining the DC voltage bus-side voltage level, a sensor provided downstream of the switching device for determining the DC voltage branch-side voltage level, a current sensor for determining current level and direction, a control device designed such that the direction and level of the current are determined, the flow of current is interrupted by the switching device when a first threshold value of the current level is exceeded, and when the first threshold value of the current level is exceeded in the reverse direction: the DC voltage bus-side voltage level is compared with the DC voltage branch-side voltage level, and the switching device is switched on upon a voltage difference being less than a voltage difference value.

An object of the present invention is to provide a drive capability switching circuit for a semiconductor element and a drive device for a semiconductor element capable of suppressing a radiation noise while reducing a loss occurred in switching of the semiconductor element. An IGBT drive capability switching circuit includes a gate voltage detection unit that detects a voltage level of a gate voltage based on a gate signal which is input to an IGBT in a mirror period, and a gate signal switching unit that switches a voltage level of the gate signal based on the voltage level detected by the gate voltage detection unit.

A driving apparatus including: gate driving circuit to drive gates of a first semiconductor element and a second semiconductor element connected in series between a positive side power supply line and a negative side power supply line; a first timing generating circuit to generate a first timing signal when voltage applied to the second semiconductor element becomes reference voltage during a turn-off period of the first semiconductor element; and a first driving condition change circuit, wherein the gate driving circuit relaxes change in a charge amount of the gate of the first semiconductor element, according to the first timing signal.

A gate-drive controller for a power semiconductor device includes a master control unit (MCU) and one or more comparators that compare the output signal of the power semiconductor device to a reference value generated by the MCU. The MCU, in response to a turn-off trigger signal, generates a first intermediate drive signal for the power semiconductor device and generates a second intermediate drive signal, different from the first drive signal, when a DSAT signal indicates that the power semiconductor device is experiencing de-saturation. The MCU generates a final drive signal for the power semiconductor when the output signal of the one or more comparators indicates that the output signal of the power semiconductor device has changed relative to the reference value. The controller may also include a timer that causes the drive signals to change in predetermined intervals when the one or more comparators do not indicate a change.

A control circuit includes a detection module configured to detect an operating condition of a semiconductor switching device; a determining module configured to determine a gate allowable voltage of the semiconductor switching device based on the operating condition; and an output module configured to output a control signal to a driving power supply circuit of the semiconductor switching device based on the gate allowable voltage, to control the driving power supply circuit to provide a gate on voltage that is not higher than the gate allowable voltage and that is positively correlated with the gate allowable voltage for the semiconductor switching device. When the operating condition of the semiconductor switching device becomes better, the gate allowable voltage of the semiconductor switching device is increased.