ACTIVE RECTIFIER AND WIRELESS POWER RECEIVING APPARATUS USING THE SAME THAT CAN REDUCE REVERSE CURRENT LEAKAGE
First Claim
1. An active rectifier, comprising:
- first and fourth switches turned on while a voltage of an alternating current (AC) input is negative, and configured to apply a current of the AC input to a rectifying capacitor;
second and third switches turned on while a voltage of the AC input is positive, and configured to apply a current of the AC input to the rectifying capacitor; and
a synchronization control unit configured to compensate for a delay time of the comparator for detecting zero-crossing of the AC input so as to switch the first to fourth switches.
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Accused Products
Abstract
An active rectifier and a wireless power reception apparatus using the same are disclosed herein. The active rectifier includes first and fourth switches, second and third switches, and a synchronization control unit. The first and fourth switches are turned on while the voltage of an alternating current (AC) input is negative, and apply the current of the AC input to a rectifying capacitor. The second and third switches are turned on while a voltage of the AC input is positive, and apply the current of the AC input to the rectifying capacitor. The synchronization control unit compensates for the delay time of the comparator for detecting zero-crossing of the AC input so as to switch the first to fourth switches.
257 Citations
12 Claims
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1. An active rectifier, comprising:
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first and fourth switches turned on while a voltage of an alternating current (AC) input is negative, and configured to apply a current of the AC input to a rectifying capacitor; second and third switches turned on while a voltage of the AC input is positive, and configured to apply a current of the AC input to the rectifying capacitor; and a synchronization control unit configured to compensate for a delay time of the comparator for detecting zero-crossing of the AC input so as to switch the first to fourth switches. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A wireless power reception apparatus, comprising:
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a resonant reception coil for receiving a radio signal, so as to generate a waveform of an AC input; an active rectifier for comprising first and fourth switches turned on while a voltage of the AC input is negative so as to apply a current of the AC input to a rectifying capacitor and second and third switches turned on while a voltage of the AC input is positive so as to apply a current of the AC input to the rectifying capacitor, and for compensating for a delay time of a comparator for detecting zero-crossing of the AC input so as to switch the first to fourth switches; and a low loss regulator for generating a DC voltage from a voltage charged in the rectifying capacitor.
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10. A delay compensation method of controlling a synchronization of an active rectifier, the active rectifier including first and fourth switches turned on while a voltage of an AC input is negative and configured to apply a current of the AC input to a rectifying capacitor and second and third switches turned on while a voltage of the AC input is positive and configured to apply a current of the AC input to the rectifying capacitor, the delay compensation method comprising:
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generating a coarse delay comparison signal by delaying a comparison signal, output from a comparator for detecting zero-crossing of the AC input, by a coarse delay time; selecting a candidate delay signal from candidate delay signals obtained by finely delaying the coarse delay comparison signal by different fine delay times; determining a coarse delay time such that a phase of a first reference delay signal, obtained by further delaying the selected candidate delay signal by a compensation delay time, is synchronized with a phase of the comparison signal; selecting a candidate delay signal from candidate delay signals obtained by further finely delaying a coarse delay comparison signal by different fine delay times, the coarse delay comparison signal being delayed by the determined coarse delay time previously; determining a fine delay time such that a phase of a second reference delay signal, obtained by further delaying the selected candidate delay signal by a compensation delay time, is synchronized with the phase of the comparison signal; and outputting a candidate delay signal, corresponding to the determined fine delay time, as a switch control signal. - View Dependent Claims (11)
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12. A method of controlling a synchronization of an active rectifier, the active rectifier including first and fourth switches turned on while a voltage of an AC input is negative so as to apply a current of the AC input to a rectifying capacitor, second and third switches turned on while a voltage of the AC input is positive, and level shifters for compensating for threshold voltages of the third and the fourth switches, the method comprising:
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outputting a first switch control signal by compensating a first comparison signal for a delay of a first comparator, the first comparison signal being output by the first comparator so as to be activated when the AC input turns from positive to negative and deactivated when the AC input turns from negative to positive; outputting a second switch control signal by compensating a second comparison signal for a delay of a second comparator, the second comparison signal being output by the second comparator so as to be activated when the AC input turns from negative to positive and deactivated when the AC input turns from positive to negative; outputting a third switch control signal by compensating a third comparison signal for a delay of a third comparator, the third comparison signal being output by the third comparator so as to be activated when the AC input turns from negative to positive and deactivated when the AC input turns from positive to negative; outputting a fourth switch control signal by compensating a fourth comparison signal for a delay of a fourth comparator, the fourth comparison signal being output by the fourth comparator so as to be activated when the AC input turns from positive to negative and deactivated when the AC input turns from negative to positive; turning on the first and the fourth switches using the first and the fourth switch control signals while a voltage of the AC input is negative, so as to apply a current of the AC input to the rectifying capacitor; and turning on the second and the third switches using the second and the third switch control signals while a voltage of the AC input is positive, so as to apply a current of the AC input to the rectifying capacitor.
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Specification