A power conversion device including a switching element includes: a temperature change estimation unit estimating temperature change in a semiconductor chip containing the switching element; a number calculator calculating the number of power cycles to fracture of the semiconductor chip due to power cycles; and a degradation degree calculator computing a degree of degradation of the semiconductor chip caused by the power cycles. The temperature change estimation unit calculates a maximum value and a minimum value of temperature of the semiconductor chip in one power cycle based on a first threshold of temperature fall allowed when it is determined that the temperature of the semiconductor chip is rising, and a second threshold of temperature rise allowed when it is determined that the temperature of the semiconductor chip is falling. The number calculator calculates the number of power cycles to fracture based on the maximum value and the minimum value.

The present disclosure provides a nitride-based bidirectional switching device with substrate potential management capability. The device has a control node, a first power/load node, a second power/load node and a main substrate, and comprises: a nitride-based bilateral transistor and a substrate potential management circuit configured for managing a potential of the main substrate. By implementing the substrate potential management circuit, the substrate potential can be stabilized to a lower one of the potentials of the first source/drain and the second source/drain of the bilateral transistor no matter in which directions the bidirectional switching device is operated. Therefore, the bilateral transistor can be operated with a stable substrate potential for conducting current in both directions.

The invention discloses a converter adaptable to a wide range output voltage and a control method thereof. The converter comprises a PWM half-bridge circuit. The control method comprises the steps of: controlling the PWM half-bridge circuit to enter into a discontinuous conduction mode by regulating a switching frequency; when the PWM half-bridge circuit is operated in the discontinuous conduction mode, oscillation occurs among the output inductor, a magnetizing inductor of the transformer and a parasitic capacitor of the PWM half-bridge circuit, and when a center point voltage of the primary switching bridge arm reaches a valley or a peak, turning on the corresponding power switch. The invention reduces switching loss by controlling the corresponding power switch in the PWM half-bridge circuit to turn on when a voltage across the power switch is oscillated to valley.

Aspects of the disclosure provide for a circuit. In some examples, the circuit includes a first transistor, a second transistor, a third transistor, a first capacitor, and a second capacitor. The first transistor comprises a drain terminal coupled to an input voltage node, a source terminal coupled to a first node, and a gate terminal coupled to a second node. The second transistor comprises a drain terminal coupled to a third node, a source terminal coupled to a fourth node, and a gate terminal coupled to a fifth node. The third transistor comprises a drain terminal coupled to a sixth node, a source terminal configured to couple to a gate terminal of a switching transistor, and a gate terminal coupled to a seventh node. The first capacitor is coupled between the first node and the third node. The second capacitor is coupled between the fourth node and the sixth node.

A hybrid switch for a power converter and a method of operating said hybrid switch, the hybrid switch comprising: at a minimum a first and a second element comprising one or more switching devices of a first semiconductor type, and at a minimum a third element comprising one or more switching devices of a second semiconductor type, wherein the second semiconductor type is different from the first semiconductor type, and wherein each element is independently configurable and connected to a separate respective control terminal; and, a controller connected to the control terminals, wherein the controller is configured to control each element independently through each respective control terminal, and wherein the controller is further configured to activate elements based on a measured or estimated current and/or power as required by an operating condition of the converter.

An image display device of the present invention comprises a display and a power supply unit, and the power supply unit comprises: a first voltage detection unit that detects an input AC voltage by using a first resistance element; a second voltage detection unit that detects an input AC voltage by using a differential circuit having a capacitor element and a second resistance element; a converter that converts the level of the input voltage on the basis of a switching operation of a switching element so as to output a DC voltage; and a control unit that may control the switching element in the converter to be turned on, on the basis of a first signal detected by the first voltage detection unit or a second signal detected by the second voltage detection unit. As such, the present invention operates stably even when an AC voltage of a square wave is applied.

Examples relate to adjusting a switching frequency of a voltage regulator to operate the voltage regulator at a predetermined power efficiency. Examples described herein include receiving load information corresponding to a component that receives regulated power from the voltage regulator, determining, from a repository, a predetermined value of the switching frequency of the voltage regulator based on the load information to attain the predetermined power efficiency of the voltage regulator and adjusting the switching frequency of the voltage regulator to the predetermined value of the switching frequency to operate the voltage regulator at the predetermined power efficiency.

A wireless power receiver includes a rectifier configured to convert a radio frequency (RF) voltage signal generated based on an RF input to a direct current (DC) voltage, and a boost converter configured to generate a voltage for battery charging using the RF voltage signal as a switching signal.

A semiconductor element drive device is provided to solve a problem that because a case of a change in the temperature of the semiconductor element or a current flowing through the semiconductor element is not take into consideration, switching loss and noise cannot be reduced sufficiently. In accordance with input sensing information (temperature T, current I), a timing control unit 3 outputs a delay signal Q to control timing of driving a current increasing circuit 5 so that a reduction of switching loss of an IGBT 101 is maximized. When the IGBT 101 is in turn-on mode or turn-off mode, the current increasing circuit 5 outputs a drive signal in response to the delay signal Q delayed by a given time from output of the drive instruction signal P. In this way, the current increasing circuit 5 increases the current that causes the gate capacitor of the IGBT 101 to be charged/discharged in response to the delay signal Q, thereby increasing a switching speed to reduce switching loss.

A method for controlling a multiphase DC-DC converter with two or more phase circuits, each with a switch arranged to control an inductor current through an inductor, the phase circuit is arranged to generate a phase current contributing to a total current to be delivered to an output side of the multiphase DC-DC converter. The method includes switching two or more of the phase circuits in Boundary Conduction Mode to generate interleaved phase current pulses, with a period length and a nominal turn-on time period of the switch; and, in at least one of the two or more of the phase circuits being switched, and for successive phases, repeatedly adapting the turn-on time period for controlling the length of the pulses of the inductor current to minimise a difference from the period length.