MULTI-IMPEDANCE RECTIFICATION FOR WIRELESS POWER TRANSFER
First Claim
1. An apparatus for wirelessly receiving power and powering or charging a load, the apparatus comprising:
- a receive coupler configured to generate an alternating current (AC) input voltage waveform in response to an externally generated magnetic field;
a rectifier circuit electrically connected to the receive coupler, the rectifier circuit comprising;
a first switch electrically connected between a first internal node and an input node electrically connected to the receive coupler to receive the input voltage waveform;
a second switch electrically connected between the input node and a second internal node;
a third switch electrically connected between the first internal node and a first output node;
a fourth switch electrically connected between the first output node and the second internal node;
a fifth switch electrically connected between the second internal node and ground;
a first capacitor electrically connected between the first internal node and the second internal node; and
a second capacitor electrically connected between the first output node and the load.
1 Assignment
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Accused Products
Abstract
A multi-level rectifier is presented that is suitable for use at high frequencies, including into MHz range such as in the 6.78 MHz band used for wireless power transfer. Depending on the amplitude of the input waveform, the rectifier can be operated in different modes. For lower input levels, the rectifier acts as a voltage doubler. For higher input levels, the impedance of the rectifier can be varied based on the input level. The rectifier is a synchronous rectifier with a front section and a back section, where the impedance is varied by changing the phase of the control signal of the back section relative to that of the front section.
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Citations
30 Claims
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1. An apparatus for wirelessly receiving power and powering or charging a load, the apparatus comprising:
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a receive coupler configured to generate an alternating current (AC) input voltage waveform in response to an externally generated magnetic field; a rectifier circuit electrically connected to the receive coupler, the rectifier circuit comprising; a first switch electrically connected between a first internal node and an input node electrically connected to the receive coupler to receive the input voltage waveform; a second switch electrically connected between the input node and a second internal node; a third switch electrically connected between the first internal node and a first output node; a fourth switch electrically connected between the first output node and the second internal node; a fifth switch electrically connected between the second internal node and ground; a first capacitor electrically connected between the first internal node and the second internal node; and a second capacitor electrically connected between the first output node and the load. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A rectification apparatus, the apparatus comprising:
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a rectifier circuit comprising a plurality of switches, the rectifier circuit configured to output a DC output voltage based on an AC input voltage waveform; and a controller circuit electrically connected to the rectifier circuit and configured to; drive the plurality of switches to cause the rectifier circuit to be configured in a first mode as a voltage doubler circuit in response to a voltage level of the input voltage waveform being below a reference voltage; and drive the plurality of switches to cause the rectifier circuit to be configured in a second mode, different than the first mode, in response to the voltage level of the input voltage waveform being above the reference voltage. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A rectification circuit, comprising:
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a control signal circuit configured to output a plurality of control signals, including a first control signal of a first clock signal, a second control signal of a second clock signal, wherein the first clock signal and the second clock signal are non-overlapping and both have a frequency substantially equal to a frequency of an input waveform, the control circuit further configured to output a third control signal and a fourth control signal; the control signal circuit configured to cause the third control signal to be maintained at a non-clocked high level in response to an input waveform amplitude being less than a reference level and configured to cause the third control signal to be a third clock signal having a frequency substantially equal to a frequency of the input waveform in response to the input waveform amplitude being greater than the reference level; the control signal circuit further configured to cause the fourth control signal to be maintained at a non-clocked low level in response to the input waveform amplitude being less than the reference level and configured to cause the fourth control signal to be a fourth clock signal having a frequency substantially equal to a frequency of the input waveform, wherein the third clock signal and the fourth clock signal are non-overlapping; and a synchronous rectifier electrically connected to receive the input waveform and generate therefrom a first output voltage, including; a) a front set of switches electrically connected to receive the input waveform, the first control signal, and the second control signal; and b) a back set of switches electrically connected to the front set of switches, the third control signal and the fourth control signal, and configured to output the first output voltage from a first output node. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
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28. A method of providing a DC output voltage from an AC input voltage waveform, the method comprising:
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rectifying the AC input voltage waveform to output the DC output voltage via a rectifier circuit comprising a plurality of switches; altering one or more control signals of the plurality of switches to cause the rectifier circuit to be configured in a first mode as a voltage doubler circuit in response to a voltage level of the input voltage waveform being below a reference voltage; and altering the one or more control signals of the plurality of switches to cause the rectifier circuit to be configured in a second mode, different than the first mode, in response to the voltage level of the input voltage waveform being above the reference voltage. - View Dependent Claims (29, 30)
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Specification