A representative phase-shift based method for using a transformer system to detect movement of an object, and associated systems and methods are disclosed. A representative transformer system detects movement of an object and includes an excitation coil configured to receive an excitation coil input signal that results from an input sinusoidal signal. The transformer further includes first and second sensing coils, and a core configured to be operatively coupled to the object. The core moves relative to the first and second sensing coils when the object moves. First and second impedance loads are connected to the first and second sensing coils, respectively. The two impedance loads have different phase-shifting characteristics. A phase-shift sensing circuit determines a phase-shift between the excitation coil input signal and the input sinusoidal signal that is correlated with a position of the core relative to the first and second sensing coils.

An isolator is configured by a transmission circuit, a transformer, and a reception circuit. A first coil of the transformer is disposed on a back surface of a first semiconductor substrate; a transmission circuit and a second coil of the transformer are disposed on a front surface. The first coil is embedded within a coil trench, is led out through an embedded via-metal-film to a substrate front surface, and is electrically connected to the transmission circuit. The second coil is disposed on an insulating layer of the substrate front surface. The reception circuit is disposed on a front surface of a second semiconductor substrate. The second coil and the reception circuit are electrically connected to each other by connecting first and third electrode pads disposed respectively on the front surfaces of the first and second semiconductor substrates through wires.

A power converter includes a transformer including a transformer including a primary winding and a secondary winding magnetically coupled to the primary winding, a bridge circuit including a switching element, and an inductor. A direct current voltage is converted into an alternating current voltage by turning on and off the switching element in the bridge circuit. An output voltage in the secondary winding is induced by supplying the alternating current voltage to the primary winding. The inductor is disposed on a path connecting the switching element and the primary winding. A resonance inductance value Lr including a leakage inductance value of the transformer and an inductance value of the inductor satisfies Formula 1.

A power converter includes a transformer including a transformer including a primary winding and a secondary winding magnetically coupled to the primary winding, a bridge circuit including a switching element, and an inductor. A direct current voltage is converted into an alternating current voltage by turning on and off the switching element in the bridge circuit. An output voltage in the secondary winding is induced by supplying the alternating current voltage to the primary winding. The inductor is disposed on a path connecting the switching element and the primary winding. A resonance inductance value Lr including a leakage inductance value of the transformer and an inductance value of the inductor satisfies Formula 1.

A sensor device includes a power line and a semiconductor device. The semiconductor device includes an inductor. The inductor is formed using an interconnect layer (to be described later using FIG. 3). The power line and the semiconductor device overlap each other when viewed from a direction perpendicular to the semiconductor device. The semiconductor device includes two inductors. The power line extends between the two inductors when viewed from a direction perpendicular to the semiconductor device.

A multilayer inductor providing improved DC superposition characteristics by a permanent magnet that emits a bias magnetic flux, and having a low-loss material as a magnetic body to improve converter conversion efficiency. The multilayer inductor has a plurality of laminated electrically insulating magnetic layers; and laminated conductive patterns, each of the conductive patterns being connected in sequence in the lamination direction forming a spiral coil inside the magnetic layer. An magnetized annular permanent magnet layer emits a magnetic flux whose direction is opposite that of a magnetic flux excited by the coil is between an outer peripheral edge of the inductor and an outer peripheral edge of the coil so as not to overlap an inner peripheral part of the magnet layer with the conductive patterns and so as to block a space between the conductive patterns and the magnet layer, in axial view of the coil.

A multilayer inductor providing improved DC superposition characteristics by a permanent magnet that emits a bias magnetic flux, and having a low-loss material as a magnetic body to improve converter conversion efficiency. The multilayer inductor has a plurality of laminated electrically insulating magnetic layers; and laminated conductive patterns, each of the conductive patterns being connected in sequence in the lamination direction forming a spiral coil inside the magnetic layer. An magnetized annular permanent magnet layer emits a magnetic flux whose direction is opposite that of a magnetic flux excited by the coil is between an outer peripheral edge of the inductor and an outer peripheral edge of the coil so as not to overlap an inner peripheral part of the magnet layer with the conductive patterns and so as to block a space between the conductive patterns and the magnet layer, in axial view of the coil.

A sensor device includes a printed circuit board, a power line, a first semiconductor device, and a second semiconductor device. The first semiconductor device includes a first inductor, and the second semiconductor device includes a second inductor. Each inductor is formed using an interconnect layer. The power line extends between the two inductors without overlapping the first and second inductor, when viewed from a direction perpendicular to a main surface of the printed circuit board.

A sensor device includes a printed circuit board, a power line, a first semiconductor device, and a second semiconductor device. The first semiconductor device includes a first inductor, and the second semiconductor device includes a second inductor. Each inductor is formed using an interconnect layer. The power line extends between the two inductors without overlapping the first and second inductor, when viewed from a direction perpendicular to a main surface of the printed circuit board.

A downsized variable inductor is disclosed. The downsized variable inductor includes: a magnetic core formed in a closed loop shape, and including an air gap portion formed by partially opening the closed loop shape; a gap core inserted and fixed to the air gap portion to be integral with the magnetic core, and served to increase an inductance and a maximum current at low current of the inductor, and a coil wound and connected to the magnetic core.