According to one embodiment, electronic circuitry includes: a detection circuit including a diode, a cathode side of the diode being connected to one end of a semiconductor switching element and an anode side of the diode being connected to a first node; a comparator circuit configured to compare a voltage of the first node and a threshold voltage and generate a first signal; a first filter connected between the first node and another end of the semiconductor switching element and configured to suppress the voltage of the first node in a first period based on a control signal indicating turn-on of the semiconductor switching element; and a control circuit configured to determine at least one of the threshold voltage and the first period based on the first signal.

According to one embodiment, electronic circuitry includes: a detection circuit including a diode, a cathode side of the diode being connected to one end of a semiconductor switching element and an anode side of the diode being connected to a first node; a comparator circuit configured to compare a voltage of the first node and a threshold voltage and generate a first signal; a first filter connected between the first node and another end of the semiconductor switching element and configured to suppress the voltage of the first node in a first period based on a control signal indicating turn-on of the semiconductor switching element; and a control circuit configured to determine at least one of the threshold voltage and the first period based on the first signal.

A drive device for driving a voltage-controlled semiconductor element. The drive device includes: a drive circuit connected to the gate of the semiconductor element via a gate resistor; a delay circuit connected to the drive circuit, for delaying a drive signal output from the drive circuit until a gate voltage of the semiconductor element enters a Miller effect period, which is a period during which the gate voltage transitionally changes, the gate voltage having temperature dependency on a chip temperature of the semiconductor element; a one-shot circuit connected to the delay circuit, for outputting a pulse signal with a pulse width shorter than the Miller effect period; a comparator that compares the gate voltage with a reference voltage; and an AND circuit that outputs an overheat detection signal in response to the gate voltage exceeding the reference voltage.

A drive device for driving a voltage-controlled semiconductor element. The drive device includes: a drive circuit connected to the gate of the semiconductor element via a gate resistor; a delay circuit connected to the drive circuit, for delaying a drive signal output from the drive circuit until a gate voltage of the semiconductor element enters a Miller effect period, which is a period during which the gate voltage transitionally changes, the gate voltage having temperature dependency on a chip temperature of the semiconductor element; a one-shot circuit connected to the delay circuit, for outputting a pulse signal with a pulse width shorter than the Miller effect period; a comparator that compares the gate voltage with a reference voltage; and an AND circuit that outputs an overheat detection signal in response to the gate voltage exceeding the reference voltage.

The invention relates to the field of power semiconductor devices. This invention discloses a drive circuit and device of a power switch. The input terminal of the drive circuit receives a pulse signal; the output terminal of the drive circuit is connected to a capacitor circuit. The capacitor circuit is used to provide a negative voltage for a first electrode of the power switch to turn off the power switch when the pulse signal is a turn-off signal; the drive circuit includes a capacitance adjustment unit. The capacitance adjustment unit includes a negative voltage adjustment element that can charge a capacitor whose voltage is lower than a predetermined voltage when the pulse signal is the turn-off signal.

A current detection circuit includes normally-on-type and a first normally-off-type switching elements with main current paths that are connected in series, and a second normally-off-type switching element that has a source and a gate that are connected to a source and a gate of the first normally-off-type switching element and a drain that is connected to a constant current source, and executes a division process by using drain voltages of the two normally-off-type switching elements.

A current detection circuit includes normally-on-type and a first normally-off-type switching elements with main current paths that are connected in series, and a second normally-off-type switching element that has a source and a gate that are connected to a source and a gate of the first normally-off-type switching element and a drain that is connected to a constant current source, and executes a division process by using drain voltages of the two normally-off-type switching elements.

A mirror clamp circuit includes a comparator having a first input terminal connectable to a first control terminal of a transistor having the first control terminal connected to the other terminal of a resistor of which one terminal is fed with an output voltage and a first terminal fed with a reference potential and a second input terminal fed with a reference voltage, a transistor switch having a second control terminal fed with a control terminal voltage based on a comparison signal output from the comparator and inserted between the first control terminal and the reference potential, an OR circuit fed with a signal based on the control terminal voltage and the output voltage, and a current feeder configured to change the amount of current fed to the comparator based on the output of the OR circuit.

A power semiconductor circuit is provided for clamping the voltage across the circuit when a power semiconductor switch is opened (i.e., turned off). The circuit may include a first surge arrester and a first semiconductor switch coupled in parallel with the power semiconductor switch. The first semiconductor switch is coupled in series with the first surge arrester. A second surge arrester may be coupled to the gate of the first semiconductor switch to control current flow through the first semiconductor switch and the first surge arrester.

A power semiconductor circuit is provided for clamping the voltage across the circuit when a power semiconductor switch is opened (i.e., turned off). The circuit may include a first surge arrester and a first semiconductor switch coupled in parallel with the power semiconductor switch. The first semiconductor switch is coupled in series with the first surge arrester. A second surge arrester may be coupled to the gate of the first semiconductor switch to control current flow through the first semiconductor switch and the first surge arrester.