Abstract: A DC voltage conversion circuit includes: a switching circuit having a plurality of switching elements; and a controller that controls operations of the plurality of switching elements. The DC voltage conversion circuit can suppress variations in an output voltage even when an input voltage fluctuates. The controller can execute asymmetric PWM control and phase shift control, performs the phase shift control when a duty ratio is lower than a predetermined ratio, and performs the asymmetric PWM control when the duty ratio is higher than or equal to the predetermined ratio. When switching between the phase shift control and the asymmetric PWM control is performed with the step-down ratios being made to match each other, a control range of the duty ratio can be increased.

Abstract: A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

Abstract: A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

Abstract: A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

Abstract: A DC voltage conversion circuit includes: a switching circuit having a plurality of switching elements; and a controller that controls operations of the plurality of switching elements. The DC voltage conversion circuit can suppress variations in an output voltage even when an input voltage fluctuates. The controller can execute asymmetric PWM control and phase shift control, performs the phase shift control when a duty ratio is lower than a predetermined ratio, and performs the asymmetric PWM control when the duty ratio is higher than or equal to the predetermined ratio. When switching between the phase shift control and the asymmetric PWM control is performed with the step-down ratios being made to match each other, a control range of the duty ratio can be increased.

Abstract: A direct-current voltage conversion circuit having on/off control with a dead-time period performed alternately on a first switch and a second switch included in a direct-current voltage conversion circuit. When alternating current flows in a series circuit part including two transformers magnetically independent, current flows in an output circuit including a secondary side of one transformer, and energy is accumulated in the other transformer. The permeabilities of the magnetic cores in the first and second transformers is between 15 and 120.

Abstract: A composite smoothing inductor that can respond to an increasing demand for downsizing, a higher driving frequency, and the like has a coupling transformer, a first smoothing inductor, a second smoothing inductor on a substrate in a concentrated manner. Two input terminals are connected to the coupling transformer. One output part of the coupling transformer is connected to the first smoothing inductor, and another output part of the coupling transformer is connected to the second smoothing inductor. The first smoothing inductor and second smoothing inductor are each connected to an output terminal. The mutual inductance of the coupling transformer is higher than the self-conductance of the first smoothing inductor and the self-conductance of the second smoothing inductor.

Abstract: A composite smoothing inductor that can respond to an increasing demand for downsizing, a higher driving frequency, and the like has a coupling transformer, a first smoothing inductor, a second smoothing inductor on a substrate in a concentrated manner. Two input terminals are connected to the coupling transformer. One output part of the coupling transformer is connected to the first smoothing inductor, and another output part of the coupling transformer is connected to the second smoothing inductor. The first smoothing inductor and second smoothing inductor are each connected to an output terminal. The mutual inductance of the coupling transformer is higher than the self-conductance of the first smoothing inductor and the self-conductance of the second smoothing inductor.