A power distribution system and method has a controller and at least one semiconductor switch. The power distribution system additionally has an on status detector which detects the status of the semiconductor switches, and an overcurrent status circuit which checks for overcurrent conditions.

An overcurrent protection circuit includes a current control part configured to control conductance of a transistor so as to limit an output current flowing when the transistor is turned on to a predetermined upper limit or less, and a duty control part configured to forcibly turning on/off the transistor at a predetermined duty ratio when a temperature protection circuit detects a temperature abnormality in a state where the current control part limits the output current.

A semiconductor device includes a power semiconductor switch; a logic circuit connected to an input terminal; an overheat detection circuit that outputs to the logic circuit an overheat detection signal when a temperature of the power semiconductor switch exceeds an overheat detection threshold; and an overcurrent detection circuit that monitors a current that flows through the power semiconductor switch and that outputs to the logic circuit and to the overheat detection circuit an overcurrent detection signal when the current that flows through the power semiconductor switch exceeds a prescribed threshold, wherein in the overheat detection circuit, the overheat detection threshold values is changed from a first threshold value to a second threshold value that is lower than the first threshold value when the overheat detection circuit receives the overcurrent detection signal from the overcurrent detection circuit.

A floating two-terminal unipolar current limiting circuit arrangement implemented with enhancement mode devices and bipolar devices with a unique voltage-current operation curve. This operation curve makes this device particularly advantageous to instrumentation systems that are intended to experience large voltage transients and long-term exposure to voltages that would normally damage measurement equipment. The present current limiting device is designed to have a large impedance value prior to a “turn-on” voltage, then quickly transitions to a low-impedance state. When the conducted current exceeds a setpoint or a high-voltage event occurs, the current limiting device further transitions to the “cutoff” region, which transition resumes the initial high-impedance state. In one embodiment the threshold current may be set with internal components, while a further embodiment allows the current setpoint to be set by external components. The current limiting device designs according to the present embodiments allow for series scaling and parallel scaling.

A device, preferably a plug-in module, for communication between a controller and a field device. The device includes contacts, wherein a first subset of the contacts is electrically conductively connected or connectable to the controller and a second subset of the contacts is electrically conductively connected or connectable to the field device. The apparatus further includes a circuit having an input electrically conductively connected to the first subset of the contacts and an output electrically conductively connected to the second subset of the contacts. The circuit includes a voltage-limiting unit adapted to limit a voltage at the output, and a current-limiting unit adapted to limit a current between the input and the output and to interrupt the current when the voltage-limiting unit responds.

(57) Abstract: A system and a method for limiting in-rush currents to a battery module (14) is provided. The system and the method include operating a power MOSFET (12) with a pulse-width-modulated, PWM gate voltage. The frequency and the duty cycle of the PWM gate voltage are iteratively selected such that the current through the battery module (12) does not exceed a current limit value (18), the battery module (14) being series connected with the MOSFET load path. In one embodiment, the frequency and the duty cycle of the PWM gate voltage are alternatively varied to gradually increase the current in the load path until a current limit value (18) is reached.

A device, preferably a plug-in module, for communication between a controller and a field device. The device includes contacts, wherein a first subset of the contacts is electrically conductively connected or connectable to the controller and a second subset of the contacts is electrically conductively connected or connectable to the field device. The apparatus further includes a circuit having an input electrically conductively connected to the first subset of the contacts and an output electrically conductively connected to the second subset of the contacts. The circuit includes a voltage-limiting unit adapted to limit a voltage at the output, and a current-limiting unit adapted to limit a current between the input and the output and to interrupt the current when the voltage-limiting unit responds.

Disclosed are a surge protection power supply clamping circuit, a chip and a communication terminal. The power supply clamping circuit comprises at least one driving unit and discharging unit; the discharging units are connected to the corresponding driving units respectively, and the driving units are connected to the same time delay unit respectively; the time delay units and the discharging units are connected to a power supply voltage and a ground line respectively. The driving units or the discharging units are sequentially controlled in the power supply voltage wiring direction, so that the sum values of an equivalent conduction resistance and an equivalent metal wiring resistance of respective discharging units are the same, and therefore, the uneven conduction of an NMOS transistor caused by different metal wiring resistances due to different metal wiring lengths of the NMOS transistor of each discharging unit can be counteracted.

A method of protecting a load circuit includes sensing a load current passing through a switch electrically in series with the load circuit, sensing a voltage drop across the switch, determining a rate of change of the voltage drop across the switch, determining whether to deactivate the switch based on the load current and the rate of change of the voltage drop across the switch, in response to determining to deactivate the switch, deactivating the switch to shut off current to the load circuit.

A circuit for a smart semiconductor switch includes an electronic switch electrically coupled between an output node and a supply node. An overcurrent protective circuit is configured to generate an overcurrent signal in response to a load current flowing through the electronic switch exceeding a first overcurrent threshold, and to cause the electronic switch to be tripped. A control circuit is configured to switch the electronic switch on and off based on an input signal in a first mode, and to drive a load connected to the output node by repeatedly switching the electronic switch on and off in a second mode, and to prevent the electronic switch from being permanently tripped by the overcurrent protective circuit.