Abstract: A ring-type device includes a wireless power receiver circuit, a radio communication circuit, and a ring-shaped structure. The wireless power receiver circuit includes a power receiver circuit, and a loop coil. The radio communication circuit operates with the loop coil serving as an antenna. The power receiver circuit and the radio communication circuit include an electronic component, and a flexible circuit board to which the electronic component is mounted. The ring-shaped structure has a lateral ring face, a top ring face, and a bottom ring face. The loop coil is disposed along the top ring face. The flexible circuit board is planar in structure in its developed condition, and is disposed in a curved configuration along the lateral ring face of the ring-shaped structure.

Abstract: A planar array coil includes a multilayer substrate at which a plurality of coils are formed and arranged on a plane of the multilayer substrate. First ends of the plurality of coils are connected to switching circuit units of a power conversion circuit, and second ends of the plurality of coils are connected to a common output part. The coils include two coil parts in which currents flow in opposite rotation directions, and one coil part of one coil is adjacent to one coil part of another coil. The plurality of coils are connected such that operation of switching circuits causes currents in regions of adjacent coil parts that extend in parallel to each other to flow in the same direction. Accordingly, adverse effects by unwanted coupling between adjacent coils are reduced and a switching power supply device that includes the planar array coil performs stable power conversion operations.

Abstract: A near-field communication device includes a communication antenna for near-field communication formed along a plane, an interface circuit connected to the communication antenna for making a signal of the near-field communication pass through the interface circuit, a wireless communication IC connected to the interface circuit for processing the signal of the near-field communication, a power reception coil arranged along the plane to surround the communication antenna, a resonant capacitor constituting, together with the power reception coil, a power reception resonant circuit, and a rectifying and smoothing circuit connected to the power reception resonant circuit. The power reception resonant circuit resonates at a frequency of the near-field communication, and magnetic flux generated in the vicinity of the power reception coil by a resonant current flowing through the power reception resonant circuit interlinks with the communication antenna.

Abstract: An IC card communicates with a reader/writer, which is induction-type read/write communication equipment, in a contactless manner. A power supply control circuit detects presence or absence of power reception in accordance with an output voltage of a power receiving circuit, detects presence or absence of predetermined communication by using an electronic functional circuit, starts to charge an electrical energy storage device by using a charging circuit when there is not the predetermined communication immediately after power reception is detected, and supplies power from a voltage conversion circuit to the electronic functional circuit without starting to charge the electrical energy storage device by using the charging circuit when there is the predetermined communication immediately after power reception is detected.

Abstract: A noise reduction circuit includes a surface-mount common mode choke coil mounted on a circuit board. Output terminals of the common mode choke coil are connected to an input capacitor via second circuit patterns. Two terminals of the input capacitor are connected to two input ends of a switching circuit via third circuit patterns. Path lengths of the second circuit patterns are longer than path lengths of the third circuit patterns. Of a plurality of current paths, the path lengths of the third circuit patterns are shortest in comparison with path lengths of other current paths. First circuit patterns are parallel and face each other to form a first parasitic capacitance, and the second circuit patterns are parallel and face each other to form second parasitic capacitances.

Abstract: A circuit board of a switching power supply device includes a positive terminal circuit pattern and a negative terminal circuit pattern that are provided on a component mount surface and respectively supply currents from input parts to two input terminals of a common mode choke coil. The positive terminal circuit pattern and the negative terminal circuit pattern are positioned in parallel and close to each other. The component mount surface of the circuit board includes a component mount surface side ground pattern arranged below the common mode choke coil. A heat dissipation ground surface of the circuit board includes a ground pattern and a plurality of heat dissipation conductor patterns. Input terminals and output terminals of the common mode choke coil are respectively electrically and thermally connected to the heat dissipation conductor patterns via through-hole conductors provided between the component mount surface and the heat dissipation ground surface.

Abstract: A wireless power-receiving device with near field communication function includes a communication antenna on a flat surface for near field communication, an interface circuit connected to the antenna and allowing a signal in the near field communication to pass, a wireless communication IC that is connected to the interface circuit and processes the signal, a receiving coil on the flat surface, a resonant capacitor included, with the receiving coil, in a receiving resonant circuit, and a rectifying/smoothing circuit connected to the receiving resonant circuit. The receiving resonant circuit resonates at a frequency for the near field communication, a resonance current flowing through the receiving resonant circuit causes a current to flow through the coil, a main flux is generated near the coil, and a magnetic path of the main flux is isolated from a magnetic path of a magnetic flux for the near field communication interlinking with the antenna.

Abstract: A wireless power transmission apparatus includes a power transmission resonance mechanism including a wireless power transmission coil and a power transmission resonance capacitor; a power transmission circuit that performs switching of the power transmission resonance mechanism at a predetermined switching frequency; a voltage conversion circuit that performs voltage conversion on an input power supply voltage; an intermediate capacitor between the voltage conversion circuit and the power transmission circuit and shared between the voltage conversion circuit and the power transmission circuit; an intermediate input current detection circuit that detects an intermediate input current input to the power transmission circuit from the voltage conversion circuit; and an electric power management circuit that, by setting an upper limit value for the intermediate input current and controlling an output voltage of the voltage conversion circuit, adjusts the amplitude of a DC voltage or current intermittently provide

Abstract: A wireless power transfer system includes a power transmission device and a power reception device. The power transmission device includes a power transmission circuit and a power transmission coil. The power reception device includes a power reception circuit and a power reception coil. The power reception device is arranged relative to the power transmission device such that the power reception coil electromagnetically couples with the power transmission coil. The power transmission circuit and the power reception circuit each set a power exclusive-use period and a signal insertion period. The power exclusive-use period is set as a main part of a repetition cycle of power transmission and reception, during which an interrupt signal for power transmission authentication is not used. The signal insertion period is set as a localized part of the repetition cycle of power transmission and reception, during which the interrupt signal for power transmission authentication is inserted.

Abstract: A switching power supply device includes a circuit board on which plural inductor windings are formed, and a common magnetic body incorporated into the circuit board from both sides. The circuit board has a common wiring line electrically connected to one end of each of the plural inductor windings in common. The common magnetic body has inner legs inserted through inside the plural inductor windings and an outer leg inserted through outside the plural inductor windings. A smoothing capacitor connected between a common wiring line and ground wiring is mounted on the circuit board to constitute a smoothing filter with the inductance of the common wiring line and the smoothing capacitor. The plural inductor windings are magnetically coupled to each other, and the common wiring line and the plural inductor windings are substantially not magnetically coupled.

Abstract: A power supply system includes an MPU, multiple power conversion circuits, and multiple extended-control circuits. The MPU supplies a digital switching driving signal to the power conversion circuit, and supplies a digital switching driving signal to the power conversion circuit. The extended-control circuit, which includes a CR circuit, generates a switching driving signal which is delayed with respect to the digital switching driving signal, and supplies the switching driving signal to the power conversion circuit. The extended-control circuit, which includes a CR circuit, generates a switching driving signal which is delayed with respect to the digital switching driving signal, and supplies the switching driving signal to the power conversion circuit.

Abstract: An IC card communicates with a reader/writer, which is inductive read/write communication equipment, in a non-contact manner. The IC card includes a proximity detection circuit that detects a proximity state to the reader/writer, a near-field communication circuit, an electronic function circuit, an electricity storage device, and a power supply control circuit. The power supply control circuit controls, based on a detection result of the proximity detection circuit, power supply from the electricity storage device to the electronic function circuit. The IC card manages and controls presence/absence and timing of power supply from the electricity storage device to the electronic function circuit and effectively controls discharging of the electricity storage device and charging of the electricity storage device.

Abstract: An electronic card with biometric authentication function includes a communication antenna for short-range wireless communication, a wireless communication IC, a receiving coil, a resonant capacitor, a rectifying and smoothing circuit, a biometric sensor, and a biometric authentication circuit. The communication antenna and the receiving coil respond to a magnetic field in the same frequency band for the short-range wireless communication. The wireless communication IC performs short-range wireless communication. The receiving coil receives power from the magnetic field in the same frequency band for the short-range wireless communication. The biometric authentication circuit causes the biometric sensor to operate by using the power received from the receiving resonant circuit.

Abstract: A short-range wireless communication device includes a coil, a capacitor, a short-range wireless communication IC, and a rectifier circuit. The short-range wireless communication IC and the rectifier circuit are connected to the coil via a node. The capacitor is connected between the node and the rectifier circuit. A receiving circuit is composed of the coil and a power-receiving circuit is composed of the coil and the capacitor. An output impedance of the receiving circuit is set larger than an output impedance of the power-receiving circuit at a communication frequency, and the output impedance of the power-receiving circuit is set smaller than the output impedance of the receiving circuit at a power-receiving frequency, by appropriately setting capacitance of the capacitor.

Abstract: A short-range wireless communication device includes a receiving circuit, a power-receiving circuit, a short-range wireless communication IC, a rectifier circuit, and a load circuit. The receiving circuit and the power-receiving circuit have a common circuit portion composed of a coil, a capacitor, and a capacitor. The coil and the capacitor constitute a first parallel resonance circuit, and the coil, the capacitor, and the capacitor constitute a second parallel series resonance circuit. The first parallel resonance circuit and the second parallel series resonance circuit function as impedance adjusting circuits, an output impedance of the receiving circuit is adjusted to be higher than or equal to a first predetermined value for realizing load modulation and an output impedance of the power-receiving circuit is adjusted to be lower than or equal to a second predetermined value for realizing power supply, and operations of the receiving circuit and the power-receiving circuit are realized.

Abstract: A noise reduction circuit includes a surface-mount common mode choke coil mounted on a circuit board. Output terminals of the common mode choke coil are connected to an input capacitor via second circuit patterns. Two terminals of the input capacitor are connected to two input ends of a switching circuit via third circuit patterns. Path lengths of the second circuit patterns are longer than path lengths of the third circuit patterns. Of a plurality of current paths, the path lengths of the third circuit patterns are shortest in comparison with path lengths of other current paths. First circuit patterns are parallel and face each other to form a first parasitic capacitance, and the second circuit patterns are parallel and face each other to form second parasitic capacitances.

Abstract: A circuit board of a switching power supply device includes a positive terminal circuit pattern and a negative terminal circuit pattern that are provided on a component mount surface and respectively supply currents from input parts to two input terminals of a common mode choke coil. The positive terminal circuit pattern and the negative terminal circuit pattern are positioned in parallel and close to each other. The component mount surface of the circuit board includes a component mount surface side ground pattern arranged below the common mode choke coil. A heat dissipation ground surface of the circuit board includes a ground pattern and a plurality of heat dissipation conductor patterns. Input terminals and output terminals of the common mode choke coil are respectively electrically and thermally connected to the heat dissipation conductor patterns via through-hole conductors provided between the component mount surface and the heat dissipation ground surface.

Abstract: High-frequency power is supplied from a power transmitter to a power receiver using an electromagnetic resonance phenomenon between the power transmitter and the power receiver. The power receiver converts the high-frequency power into a power reception direct-current power to charge a battery. A power reception control unit in the power receiver detects a state of charge of the battery and generates a power transmission stop signal on the basis of the state of charge of the battery. A resonance modulation circuit in the power receiver changes resonance conditions in response to the power transmission stop signal. An MPU in the power transmitter demodulates the power transmission stop signal based on an electric variable from a power transmission direct-current power supply due to a change in the resonance conditions and stops an operation of supplying the high-frequency power in a transmission power conversion circuit for a predetermined period.

Abstract: Converter units of a power supply system apparatus each perform feedback control using an individual voltage feedback loop. Master-slave control for synchronizing oscillation control signals is performed in such a manner that master control of the converter unit and slave control of the converter unit are performed. The oscillation control signals are set in such a manner that a phase difference occurs between a plurality of power conversion circuits in association with the number of power conversion circuits that are operate. The power supply system apparatus supplies power to a load, while causing the converter units to be synchronized with each other and performing a voltage conversion operation for converting the voltage of an input power supply using a plurality of power conversion circuits in the converter units.

Abstract: A switching power supply apparatus includes switching elements that generate switching current flowing through an inductor, a switching control circuit, and an inductor current detection circuit that detects current flowing through the inductor. The inductor current detection circuit is composed of a time constant circuit including a detection capacitor and a detection resistor that are connected in series to each other and is connected in parallel to the inductor. A time constant of the inductor current detection circuit has characteristics varied with frequency or temperature. This compensates variation of equivalent series resistance of the inductor with respect to the frequency or variation thereof with respect to the temperature.