Provided is a control unit of a power conversion device configured to select, in each first set cycle, a first target switching element and a second target switching element from a plurality of switching elements connected in parallel to each other. The control unit performs control so that, at a time of a turn-on operation of a switching circuit, a turn-on start time of the first target switching element is earlier by a first set time period than a turn-on start time of another switching element that is not the first target switching element. The control unit performs control so that, at a time of a turn-off operation of the switching circuit, a turn-off start time of the second target switching element is later by a second set time period than a turn-off start time of another switching element that is not the second target switching element.

A semiconductor circuit includes: a first inductor part configured to connect in series with a source electrode of a first semiconductor element; and a second inductor part configured to connect in series with a source electrode in a second semiconductor element that is configured to connect in parallel with the first semiconductor element; the first inductor part and the second inductor part are arranged to generate an induced electromotive force in the first inductor part and the second inductor part by way of a magnetic interaction so that the currents flowing in the first inductor part and the second inductor part are reinforced in the same direction.

A semiconductor device includes a junction field effect transistor (JFET) including a source electrode, a drain electrode, and a gate electrode, and a metal oxide semiconductor field effect transistor (MOSFET) including a source electrode, a drain electrode, and a gate electrode. The JFET and the MOSFET are cascode-connected such that the source electrode of the JFET and the drain electrode of the MOSFET are electrically connected. A gate voltage dependency of the JFET or a capacitance ratio of a mirror capacitance of the MOSFET to an input capacitance of the MOSFET is adjusted in a predetermined range.

A semiconductor device includes a junction field effect transistor (JFET) including a source electrode, a drain electrode, and a gate electrode, and a metal oxide semiconductor field effect transistor (MOSFET) including a source electrode, a drain electrode, and a gate electrode. The JFET and the MOSFET are cascode-connected such that the source electrode of the JFET and the drain electrode of the MOSFET are electrically connected. A gate voltage dependency of the JFET or a capacitance ratio of a mirror capacitance of the MOSFET to an input capacitance of the MOSFET is adjusted in a predetermined range.

A semiconductor device includes a MOSFET including a drift layer, a channel layer, a trench gate structure, a source layer, a drain layer, a source electrode, and a drain electrode. The trench gate structure includes a trench penetrating the channel layer and protruding into the drift layer, a gate insulating film disposed on a wall surface of the trench, and a gate electrode disposed on the gate insulating film. A portion of the trench protruding into the drift layer is entirely covered with a well layer, and the well layer is connected to the channel layer.

A semiconductor device includes a MOSFET including a drift layer, a channel layer, a trench gate structure, a source layer, a drain layer, a source electrode, and a drain electrode. The trench gate structure includes a trench penetrating the channel layer and protruding into the drift layer, a gate insulating film disposed on a wall surface of the trench, and a gate electrode disposed on the gate insulating film. A portion of the trench protruding into the drift layer is entirely covered with a well layer, and the well layer is connected to the channel layer.

A device to convert a detected voltage, that is indicative of current conducted by a switching circuit, to a series of electrical pulses that is indicative of electrical power dissipated by the switching circuit responsive to the current. The device includes a transconductor circuit including a first circuit to receive a reference current and a first reference voltage, and to obtain a transconductance based on an auto-generated bias current and the reference current and the first reference voltage, where a value of the transconductance is determined by the reference current and the first reference voltage. The transconductor circuit further includes a second circuit coupled to the first circuit to receive the detected voltage, and to generate a first current based on the detected voltage and the obtained transconductance.

A device to convert a detected voltage, that is indicative of current conducted by a switching circuit, to a series of electrical pulses that is indicative of electrical power dissipated by the switching circuit responsive to the current. The device includes a transconductor circuit including a first circuit to receive a reference current and a first reference voltage, and to obtain a transconductance based on an auto-generated bias current and the reference current and the first reference voltage, where a value of the transconductance is determined by the reference current and the first reference voltage. The transconductor circuit further includes a second circuit coupled to the first circuit to receive the detected voltage, and to generate a first current based on the detected voltage and the obtained transconductance.

A conversion circuit and an adapter that resolve a voltage drop problem of a power supply of a driver in an ACF circuit. The conversion circuit includes an active clamp flyback circuit, a drive circuit, and a replenishment power transistor. The active clamp flyback circuit is configured to perform power conversion. The drive circuit is configured to output a drive signal and a reference voltage. The drive signal is used to drive the active clamp flyback circuit. A first terminal of the replenishment power transistor is coupled to an input terminal of the active clamp flyback circuit, a second terminal of the replenishment power transistor is coupled to a power supply terminal of the drive circuit, and a gate of the replenishment power transistor is configured to receive the reference voltage.

A conversion circuit and an adapter that resolve a voltage drop problem of a power supply of a driver in an ACF circuit. The conversion circuit includes an active clamp flyback circuit, a drive circuit, and a replenishment power transistor. The active clamp flyback circuit is configured to perform power conversion. The drive circuit is configured to output a drive signal and a reference voltage. The drive signal is used to drive the active clamp flyback circuit. A first terminal of the replenishment power transistor is coupled to an input terminal of the active clamp flyback circuit, a second terminal of the replenishment power transistor is coupled to a power supply terminal of the drive circuit, and a gate of the replenishment power transistor is configured to receive the reference voltage.