Abstract: Provided are an apparatus and method for monitoring a wireless power transmitter. The apparatus for monitoring the wireless power transmitter includes a magnitude information detector included in a resonator of the wireless power transmitter and configured to detect magnitude information of voltages at opposite ends of an impedance device connected to the resonator, a phase difference detector configured to detect phase difference information of the voltages at the opposite ends of the impedance device, and a controller configured to monitor a state of the resonator on the basis of the magnitude information of the voltages at the opposite ends of the impedance device and the phase difference information, which are detected by the magnitude information detector and the phase difference detector.

Abstract: A dual band wireless power reception unit is disclosed. The wireless power reception unit according to one embodiment comprises: a first resonator; a second resonator connected to the first resonator in parallel; a single rectifier having, as an input, a node in which outputs of the first resonator and the second resonator are connected to each other in parallel; at least one switch having a first output, a second output, and an input, wherein the second output is connected to the ground; at least one capacitor connected to the second resonator in parallel, and of which one terminal is connected to the first output of the switch and the other terminal is connected to the rectifier input; and a frequency sensor sensing an input frequency from the rectifier input, and of which an output is connected to the input of the switch.

Abstract: A magnetic resonance wireless power transmission device capable of adjusting resonance frequency is disclosed. A wireless power transmission device according to an embodiment of the present invention comprises: a power amplifier for amplifying a wireless power signal using a driving frequency signal; a resonator for configuring a resonance tank and wirelessly transmitting, through magnetic resonance, the wireless power signal output from the power amplifier using a resonance frequency of the resonance tank; and a resonance control unit for controlling a duty ratio using a frequency applied to the resonator or a frequency signal generated by the resonator and adjusting the resonance frequency of the resonator.

Abstract: A wireless power receiver is disclosed. The wireless power receiver according to an embodiment of the present invention comprises: a resonator for receiving wireless power; a rectifier for converting alternating current power received from the resonator to direct current power and supplying output power to a load; and a control unit for adjusting a resonant frequency of the resonator to directly control the output power of the rectifier supplied to the load.

Abstract: A wireless power receiver is disclosed. The wireless power receiver according to an embodiment of the present invention comprises: a resonator for receiving wireless power; a rectifier for converting alternating current power received from the resonator to direct current power and supplying output power to a load; and a control unit for adjusting a resonant frequency of the resonator to directly control the output power of the rectifier supplied to the load.

Abstract: A dual band wireless power reception unit is disclosed. The wireless power reception unit according to one embodiment comprises: a first resonator; a second resonator connected to the first resonator in parallel; a single rectifier having, as an input, a node in which outputs of the first resonator and the second resonator are connected to each other in parallel; at least one switch having a first output, a second output, and an input, wherein the second output is connected to the ground; at least one capacitor connected to the second resonator in parallel, and of which one terminal is connected to the first output of the switch and the other terminal is connected to the rectifier input; and a frequency sensor sensing an input frequency from the rectifier input, and of which an output is connected to the input of the switch.

Abstract: An active diode having an improved transistor turn-off control method is disclosed. The active diode comprises: a comparator for comparing voltages of both ends of a parasitic diode of a transistor; and a gate driver for controlling a gate terminal of the transistor according to the comparison result of the comparator, and estimates a turn-on time of the transistor and uses the same to control the gate terminal of the transistor.

Abstract: A magnetic resonance wireless power transmission device capable of adjusting resonance frequency is disclosed. A wireless power transmission device according to an embodiment of the present invention comprises: a power amplifier for amplifying a wireless power signal using a driving frequency signal; a resonator for configuring a resonance tank and wirelessly transmitting, through magnetic resonance, the wireless power signal output from the power amplifier using a resonance frequency of the resonance tank; and a resonance control unit for controlling a duty ratio using a frequency applied to the resonator or a frequency signal generated by the resonator and adjusting the resonance frequency of the resonator.

Abstract: An active diode having an improved transistor turn-off control method is disclosed. The active diode comprises: a comparator for comparing voltages of both ends of a parasitic diode of a transistor; and a gate driver for controlling a gate terminal of the transistor according to the comparison result of the comparator, and estimates a turn-on time of the transistor and uses the same to control the gate terminal of the transistor.

Abstract: An active diode driver for operating a switch of an active rectifier using an active diode is provided. The active diode driver may first control a soft turn-on of the switch and secondly control a hard turn-on of the switch, thereby making it possible for the switch to be softly turned-on.

Abstract: An active diode that features improved control of transistor turn-off is provided. Such an active diode may include a comparator to compare voltages between opposite ends of a parasitic diode, and a gate driver to control a gate terminal of the transistor according to the comparison result of the comparator. Furthermore, the active diode may further include an off-timing controller to control the transistor to be turned off at a point in time when voltages of the opposite ends of the parasitic diode turn positive. Thus, the active diode may be turned off when required.

Abstract: A gate driver driving a switching device is disclosed. The gate driver includes a capacitor which is coupled to the input of the switching device. The gate drive power consumption is reduced by this additional capacitor.

Abstract: An active diode that features improved control of transistor turn-off is provided. Such an active diode may include a comparator to compare voltages between opposite ends of a parasitic diode, and a gate driver to control a gate terminal of the transistor according to the comparison result of the comparator. Furthermore, the active diode may further include an off-timing controller to control the transistor to be turned off at a point in time when voltages of the opposite ends of the parasitic diode turn positive. Thus, the active diode may be turned off when required.

Abstract: A gate driver driving a switching device is disclosed. The gate driver includes a capacitor which is coupled to the input of the switching device. The gate drive power consumption is reduced by this additional capacitor.

Abstract: An active diode driver for operating a switch of an active rectifier using an active diode is provided. The active diode driver may first control a soft turn-on of the switch and secondly control a hard turn-on of the switch, thereby making it possible for the switch to be softly turned-on.

Abstract: A LED driving system and method suitable for driving one or more LEDs or strings of LEDs connected to a common output terminal which is driven with a boost converter. A LED ON signal indicates when the LEDs are to be turned on, with the boost converter nominally operated only when the LEDs are to be on. To enable a lower minimum LED duty cycle without risking boost voltage collapse, the LED ON signal may be delayed such that the LEDs are turned on after the boost converter. A second technique, which may be used in conjunction with the first, adaptively extends the operation time of the boost converter beyond the time at which LED ON turns off the LEDs.

Abstract: A LED driving system and method suitable for driving one or more LEDs or strings of LEDs connected to a common output terminal which is driven with a boost converter. A LED ON signal indicates when the LEDs are to be turned on, with the boost converter nominally operated only when the LEDs are to be on. To enable a lower minimum LED duty cycle without risking boost voltage collapse, the LED ON signal may be delayed such that the LEDs are turned on after the boost converter. A second technique, which may be used in conjunction with the first, adaptively extends the operation time of the boost converter beyond the time at which LED ON turns off the LEDs.