A semiconductor switch control device includes a first FET and a second FET arranged adjacent to each other, in which source terminals are connected in series. A drain terminal of the first FET is connected to a high voltage battery, and a drain terminal of the second FET is connected to a high voltage load. A controller determines a temperature state of a minus-side main relay including the second FET based on a forward voltage of a body diode of the first FET.

In accordance with an embodiment, an electronic circuit includes a first transistor device, at least one second transistor device, and a drive circuit. The first transistor device is integrated in a first semiconductor body, and includes a first load pad at a first surface of the first semiconductor body and a control pad and a second load pad at a second surface of the first semiconductor body. The at least one second transistor device is integrated in a second semiconductor body, and includes a first load pad at a first surface of the second semiconductor body and a control pad and a second load pad at a second surface of the second semiconductor body. The first load pad of the first transistor device and the first load pad of the at least one second transistor device are mounted to an electrically conducting carrier.

A protection and attenuation circuit for sensitive AC loads is described. The circuit provides AC power protection and attenuation utilizing high-efficiency switch-mode techniques to attenuate an AC power signal by incorporating a bidirectional, transistorized switch driven from a pulse width modulation signal, PWM. The circuit monitors characteristics of the AC power signal driving a known load and characteristics of the load or other elements and determines the duty cycle of the pulse width modulated signal, PWM, based upon the duration and amplitude of the over-voltage, over-current, over-limit or other event.

The present invention discloses a short-circuit-protection electronic switch serial connect to the load, which is applied to the load control in a DC or AC power supply occasion. With load over-current and short-circuit-protection function, it is characterized in that the primary switch component is a part of the cut-off-type positive feedback protective trigger circuit, the primary switch component and the positive feedback gate element form a cut-off-type positive feedback protective trigger circuit. It can be widely applied to directly turn-on and turn-off control of all kinds of serial connection AC or DC load devices phase angle control and PWM control fields.

A semiconductor device according to an embodiment includes a normally-off transistor having a first source, a first drain, and a first gate; a normally-on transistor having a second source electrically connected to the first drain, a second drain, and a second gate, a capacitor having a first end and a second end, the second end being electrically connected to the second gate, a first diode having a first anode electrically connected between the second end and the second gate and having a first cathode electrically connected to the second source, a first resistor provided between the first end and the first gate, and a second diode having a second anode electrically connected to the first end and having a second cathode electrically connected to the first gate, the second diode being provided in parallel with the first resistor.

A switching circuit includes a power switch, an active clamping circuit, and an active clamping control unit. When the power switch is modulated between an ON state and an OFF with a predetermined frequency, the active clamping control unit is configured to activate the function of the active clamping circuit for absorbing the energy of voltage surges. When the power switch is operating in the ON state or the OFF state, the active clamping control unit is configured to deactivate the function of the active clamping circuit for preventing the counter EMF from damaging the power switch.

There has been a problem in semiconductor apparatuses of related art in which a circuit operation cannot be returned after a reverse current occurred. In one embodiment, a semiconductor apparatus includes a timer block configured to count up a count value to a predetermined value in response to a control signal being enabled, the control signal instructing a power MOS transistor to be turned on, and a protection transistor including a drain connected to a gate of the power MOS transistor, a source and a back gate connected to a source of the power MOS transistor, and an epitaxial layer in which the power MOS transistor is formed, the epitaxial layer being supplied with a power supply voltage. The protection transistor short-circuits the source and gate of the power MOS transistor in response to an output voltage of the power MOS transistor meeting a predetermined condition and the count value reaching the predetermined value. The timer block resets the count value when the output voltage of the power MOS transistor no longer meets the predetermined condition.

Provided is a load drive device capable of diagnosing a failure of an output terminal of the load drive device before a charging voltage stabilizes in a configuration in which a capacitor is connected to an output terminal of the load drive device that drives an inductive load. In the load drive device according to the present invention, a capacitor is connected between a load terminal and a ground terminal, and the presence or absence of a failure of the load terminal is diagnosed on the basis of a current flowing between an internal power supply included in a diagnosis circuit and the load terminal.

This device for actively discharging an electrical energy storage device has a branch having first and second ends connected respectively to positive and negative terminals of the electrical energy storage device, and between the two ends, a thermistor having a resistance that increases with a temperature of the thermistor and a switch designed to receive a control signal (v.sub.GS) to change from an open state to a closed state, the thermistor and the switch being connected to one another so that, when the switch is closed, a discharge current (i.sub.D) enters through the first end, flows through the thermistor (210) and the switch one after the other, and emerges through the second end; and a device for controlling the switch. The control device is connected to the switch so as to provide the control signal (v.sub.GS) independently of the resistance of the thermistor.

A load control device for controlling power delivered from an AC power source to an electrical load may have a closed-loop gate drive circuit for controlling a semiconductor switch of a controllably conductive device. The controllably conductive device may be coupled in series between the source and the load. The gate drive circuit may generate a target signal in response to a control circuit. The gate drive circuit may shape the target signal over a period of time and may increase the target signal to a predetermined level after the period of time. The gate drive circuit may receive a feedback signal that indicates a magnitude of a load current conducted through the semiconductor switch. The gate drive circuit may generate a gate control signal in response to the target signal and the feedback signal, and render the semiconductor switch conductive and non-conductive in response to the gate control signal.