Methods, systems, and devices for protecting a wireless power transfer system. One aspect features a sensor network for a wireless power transfer system. The sensor network includes a differential voltage sensing circuit and a current sensing circuit. The differential voltage sensing circuit is arranged within a wireless power transfer system to measure a rate of change of a voltage difference between portions of an impedance matching network and generate a first signal representing the rate of change of the voltage difference. The current sensing circuit is coupled to the differential voltage sensing circuit and configured to calculate, based on the first signal, a current through a resonator coil coupled to the wireless power transfer system.

A method of controlling an electric power assisted steering (EPS) system comprising one or more inverter bridges each connected to a multi-phase motor configured to provide power assist to steering of a vehicle, each inverter comprising a plurality of switching elements each associated with a phase of the motor, is provided. The method comprises, preventing current flow in said one or more affected inverters by applying a gate-source voltage to one or more of the switching elements of the affected inverter bridge(s) in response to detecting a predefined event affecting current flow in one or more of the inverter bridges. A control system for an electric power assisted steering apparatus comprising one or more inverter bridges and a control means configured to control the switching elements in accordance with the method is also provided.

A power converter comprising an energy transfer element is coupled between an input of the power converter and an output of the power converter. A cascode circuit generates a first sense signal and a second sense signal. A controller controls the switching of the cascode circuit to transfer energy from the input of the power converter to the output of the power converter. The controller comprising a current sense circuit generates a current limit signal and an overcurrent signal in response to the first sense signal and the second sense signal. A control circuit generates a control signal in response to the current limit signal and the overcurrent signal. A drive circuit comprising a first stage gate drive circuit generates a drive signal in response to the control signal to reduce EMI, and a second stage of gate drive circuit to enable accurate current sensing of the cascode circuit.

A switching circuit includes: a detection wiring configured to receive a potential changing depending on a current of a first switching element; a first circuit connected between the detection wiring and a first having a first time constant, and making the first wiring follow the potential of the detection wiring; a second circuit connected between the detection wiring and a second wiring, having a second time constant larger than the first time constant, and making the second wiring fellow the potential of the detection wiring; a potential maintaining circuit configured to maintain the second wiring at a potential higher than the potential of the first wiring while a current is not flow through the first switching element; and a control circuit configured to turn off the first switching element in a case where the potential of the first wiring exceeds the potential of the second wiring.

A semiconductor device protection circuit for a semiconductor device driving circuit that switches a voltage-controlled semiconductor device ON and OFF includes a current detection circuit that detects current flowing through the semiconductor device and generates and outputs a current detection voltage representing the detected current; an overcurrent detection circuit that compares the current detection voltage to a variable overcurrent detection threshold voltage so as to detect for overcurrent flowing through the semiconductor device; a protection circuit that, when the overcurrent detection circuit detects overcurrent, controls the ON/OFF switching of the semiconductor device so as to prevent thermal breakdown of the semiconductor device; and a gate voltage detection circuit that, in accordance with a gate voltage of the semiconductor device, selectively sets the overcurrent detection threshold voltage to either a first threshold voltage or a second threshold voltage that is lower than the first threshold voltage.

A low-side driving circuit forms a power conversion apparatus together with a power transistor to be driven. A protection circuit generates a protection signal S1. An alarm control circuit changes an electrical state of a fail terminal according to the protection signal S1. A judgment circuit compares a voltage V.sub.FO at a fail (FO) terminal with a predetermined threshold value, and generates a judgment signal S2 that indicates the comparison result. A control logic circuit controls the state of the power transistor based on the judgment signal S2 and the protection signal S1.

A power converter comprising an energy transfer element is coupled between an input of the power converter and an output of the power converter. A cascode circuit generates a first sense signal and a second sense signal. A controller controls the switching of the cascode circuit to transfer energy from the input of the power converter to the output of the power converter. The controller comprising a current sense circuit generates a current limit signal and an overcurrent signal in response to the first sense signal and the second sense signal. A control circuit generates a control signal in response to the current limit signal and the overcurrent signal. A drive circuit comprising a first stage gate drive circuit generates a drive signal in response to the control signal to reduce EMI, and a second stage of gate drive circuit to enable accurate current sensing of the cascode circuit.

A communication system for use in a switching module includes a low-side control block coupled to control switching of a low-side switch of the switching module. The low-side control block is further coupled to be referenced with a low-side reference system ground. A high-side control block is coupled to control switching of a high-side switch of the switching module. The high-side control block is further coupled to be referenced with a floating node of the switching module. During steady state operation, the low-side control block is coupled to send signals during each switching cycle to the high-side control block to turn the high-side switch on and off. A status update is communicated from the high-side control block to the low-side control block through a first single-wire communication link.

Provided is a power conversion device with which it is possible to acquire a sign of a system stop before the system stops, and to minimize the nonworking time of the system. A power conversion device for converting DC voltage or AC voltage into AC voltage, the power conversion device being characterized by having an abnormality detection unit for detecting abnormalities in the power conversion device, a restart unit for stopping the power conversion device and automatically performing a restart when the abnormality detection unit has detected an abnormality, a restart recording unit for recording restart information of when the restart unit has restarted, and a sign diagnostic unit for inputting the restart information recorded by the restart recording unit and performing a sign diagnosis of the abnormality in the power conversion device on the basis of the restart information, the sign diagnostic unit performing the sign diagnosis on the basis of the number of restarts and outputting a sign diagnostic result.

A gate driver circuit is provided that includes a high-side power transistor; a low-side power transistor coupled to the high-side power transistor, where an output voltage is generated at a load node coupled between the low-side power transistor and the high-side power transistor; a gate driver configured to receive a high-side control signal and a low-side control signal, drive the high-side power transistor based on the high-side control signal, and drive the low-side power transistor based on the low-side control signal; and a short circuit detection circuit configured to monitor for short circuit events at the high-side power transistor and at the low-side power transistor based on the high-side control signal, the low-side control signal, and the output voltage, and, generate a fault signal in response to detecting a short circuit event at either of the high-side power transistor or the low-side power transistor.