A power supply control apparatus detects a failure of a semiconductor switch element in a switching circuit having semiconductor series circuits each having semiconductor switch elements connected in series with reverse polarities. The power supply control apparatus includes a reference resistance value storing unit storing information on a combined resistance value between an input and an output of the switching circuit, a conduction current detection unit configured to detect a current flowing through the switching circuit, a potential difference detection unit configured to detect an input-output potential difference between the input and the output of the switching circuit, a voltage drop calculation unit configured to calculate an assumed voltage drop, a voltage comparison unit configured to compare the input-output potential difference with the assumed voltage drop, and a failure identification unit configured to identify a failure of the semiconductor switch element.

A circuit arrangement is disclosed for controlling the switching of a field effect transistor (FET). A current controlled amplifier may be configured to amplify a current in a current sense device to generate an amplified current, wherein the current in the current sense device indicates a current through the FET. A comparator may be coupled to the current sense amplifier to compare a voltage corresponding to the amplified current with a voltage reference and to generate a comparator output based on the comparison, wherein the comparator output controls whether the FET is on or off.

The present disclosure provides techniques for predicting failure of power switches and taking action based on the predictions. In an example, a method can include controlling the at least two parallel-connected power switches via a first driver and a second driver, the first a second driver responsive to a single command signal, measuring a failure characteristic of a first power switch, and disabling a first driver of the first power switch when the first failure characteristic exceeds a failure precursor threshold.

A large current flowing when energization by normal load drive control is performed at the time of a load short-circuit is prevented. A load drive device 100 includes drive switches 61 and 62 that turn on or off the current supplied from a power source to a load 70, a switch drive circuit 20 that transmits a drive signal to the drive switches 61 and 62 based on a control command from an arithmetic device 10, and a constant current source 40 that supplies the current to the load 70 without passing through the drive switches 61 and 62. Then, the switch drive circuit 20 performs control so as not to turn on either the drive switches 61 or 62 when the voltage between both ends of the load 70 becomes equal to or less than the determination value in a state where the drive switches 61 and 62 are turned off and in a state where the current is supplied from the constant current source 40 to the load 70.

A driver circuit is configured to deliver drive signals from an output pin to a power switch to control ON/OFF switching of the power switch. A first detection pin of the driver circuit is configured to receive a first signal associated with the power switch, wherein the first signal indicates a voltage drop over the power switch and a voltage drop over one or more other circuit elements. A second detection pin is configured to receive a second signal, wherein the second signal indicates a voltage drop over one or more matched circuit elements, wherein the one or more matched circuit elements associated with the second signal are substantially identical to the one or more other circuit elements associated with the first signal. The driver circuit is configured to determine the voltage drop over the power switch based on a difference between the first signal and the second signal.

An integrated circuit may include a power transistor coupled between a supply pin and an output pin; a current sensing circuit configured to sense a load current passing through the power transistor and to provide a respective current sense signal; a first configuration pin; a current output circuit configured to provide a diagnosis current at a current output pin; a diagnosis pin for receiving a diagnosis request signal; and a control circuit configured to: select a characteristic curve representing a current versus time characteristic dependent on a external circuit connected to the first configuration pin; generate a drive signal for the power transistor dependent on the selected characteristic curve and the current sense signal; and control—dependent on a pulse pattern of the diagnosis request signal—the current output circuit to set the value of the diagnosis current such that it represents the load current or the selected characteristic curve.

A circuit for detecting faults affecting a power transistor comprises a conditioning circuit, a first fault status circuit, and a fault signaling circuit. The power transistor is turned on and off by assertion and de-assertion, respectively, of an input signal. The conditioning circuit produces a conditioned gate voltage signal from a gate voltage of the power transistor. The first fault status circuit asserts a first fault indication when the conditioned gate voltage signal is greater than a first fault reference voltage during a first interval after the assertion of the input signal. The fault signaling circuit asserts a fault signal in response to the first fault indication being asserted, and de-asserting the fault signal in response to the input signal being de-asserted.

A system includes a sensor circuit configured to sense a parameter of a power system having an operating voltage greater than a voltage rating of the sensor circuit, an optical communications circuit configured to receive a sensor signal from the sensor circuit and to generate an optical communications signal therefrom, and an optical power supply circuit configured to receive an optical input, to generate electrical power from the received optical input and to supply the generated electrical power to the sensor circuit and the optical communications circuit. A driver circuit may be configured to generate a first control signal applied to a control terminal of the power semiconductor switch, and the optical power supply circuit may be configured to supply the generated electrical power to the sensor circuit, the optical communications circuit and the driver circuit.

An output module of an industrial control apparatus includes an output circuit controlling an electrical connection between a power supply terminal and an output terminal and a controller controlling an operation of the output circuit. The output circuit includes multiple switches, which are connected in series between the power supply terminal and the output terminal, and a voltage divider circuit outputting a divided voltage. The controller controls on/off states of the switches, and detects a short circuit of the switches based on the divided voltage. When the divided voltage detected during an off period while the multiple switches are in off states is within a normal voltage range, the controller determines that no short circuit is occurred. When the divided voltage detected during the off period is out of the normal voltage range, the controller determines that a short circuit is occurred in at least one of the switches.

According to one embodiment, a deterioration checking apparatus includes an inductor that is connected in series to a main current path of a MOS transistor to be checked, and forms a closed loop together with the MOS transistor when the MOS transistor is in an ON-state, a control circuit that controls ON/OFF of the MOS transistor, a current sensor that detects a current released from the inductor, and a calculation circuit that calculates an ON-resistance of the MOS transistor from an attenuation characteristic of a current released from the inductor when the MOS transistor is in an ON-state, and calculates a threshold voltage of the MOS transistor from an attenuation characteristic of a current released from the inductor when the MOS transistor is in an OFF-state. Therefore, it is possible to easily check a deterioration state of the MOS transistor.