Resonant wireless power receiver circuit and control circuit and wireless power conversion method thereof

Patent metadata

Field	Value
Publication number	US-2016336808-A1
Application number	US-201615144553-A
Country	US
Kind code	A1
Filing date	May 2, 2016
Priority date	May 15, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

The present invention provides a resonant wireless power receiver circuit, including: a resonant circuit for receiving a wireless power to generate an AC resonant signal; a switch controlled rectifier circuit which includes a multi-mode switch circuit, for rectifying the AC resonant signal into a rectifier output signal to drive a load, wherein the multi-mode switch circuit includes at least one multi-mode switch; and a feedback control circuit for generating a switch control signal according to a feedback signal related to the rectifier output signal to control the at least one multi-mode switch such that it operates at least in a Resonance Short Circuit Operation to limit the rectifier output signal or to regulate the rectifier output signal. In the Resonance Short Circuit Operation, a positive resonant output node and a negative resonant output node are short-circuited by the multi-mode switch circuit.

First claim

What is claimed is:

1 . A resonant wireless power receiver circuit, comprising:
a resonant circuit which includes a receiver coil, configured to operably receive a wireless power to generate an AC resonant signal between a positive resonant output node and a negative resonant output node, wherein the AC resonant signal includes an AC resonant voltage, and the AC resonant voltage has an amplitude; a switch controlled rectifier circuit, configured to operably convert the AC resonant signal to generate a rectified output signal between a rectified output node and a ground node, wherein the rectified output signal includes a rectified output voltage and a rectified output current, wherein the switch controlled rectifier circuit includes a multi-mode switch circuit which includes at least one multi-mode switch; and a feedback control circuit, configured to operably generate a multi-mode switch control signal for controlling the multi-mode switch circuit according to a voltage feedback signal related to the rectified output voltage and/or a current feedback signal related to the rectified output current, such that the multi-mode switch circuit operates at least in a portion of time in a Resonance Short Circuit Operation to limit a level of the rectified output voltage not larger than a rectified output voltage threshold, and/or to limit a level of the rectified output current not larger than a rectified output current threshold, and/or to regulate the rectified output voltage at a level corresponding to a level of an output voltage reference signal, and/or to regulate the rectified output current at a level corresponding to a level of an output current reference signal; wherein in the “Resonance Short Circuit Operation”, the multi-mode switch circuit operates such that the positive resonant output node and the negative resonant output node are short-circuited.

2 . The resonant wireless power receiver circuit of claim 1 , wherein the switch controlled rectifier circuit includes a bridge rectifier circuit which includes a first rectifier device, a second rectifier device, and the multi-mode switch circuit, wherein the multi-mode switch circuit includes a first multi-mode switch and a second multi-mode switch, wherein each of the first rectifier device, the second rectifier device, the first multi-mode switch and the second multi-mode switch has a current inflow node and a current outflow node;
wherein the bridge rectifier circuit is configured as (A) or (B): (A) the current outflow nodes of the first rectifier device and the second rectifier device being connected to each other at the rectified output node; the current inflow nodes of the first multi-mode switch and the second multi-mode switch being connected to each other at the ground node; the current inflow node of the first rectifier device and the current outflow node of the first multi-mode switch being connected to each other at the negative resonant output node; and the current inflow node of the second rectifier device and the current outflow node of the second multi-mode switch being connected to each other at the positive resonant output node; or (B) the current outflow nodes of the first multi-mode switch and the second multi-mode switch being connected to each other at the rectified output node; the current inflow nodes of the first rectifier device and the second rectifier device being connected to each other at the ground node; the current inflow node of the first multi-mode switch and the current outflow node of the first rectifier device being connected to each other at the negative resonant output node; and the current inflow node of the second multi-mode switch and the current outflow node of the second rectifier device being connected to each other at the positive resonant output node; wherein the feedback control circuit controls the first and the second multi-mode switches by the multi-mode switch control signal, such that the first and the second multi-mode switches operate in a time-divided combination of any two or more among a Synchronous Rectifying Switching Operation, a Resonance Short Circuit Operation, and an OSOC (One Synchronous-rectifying-switching, One Conductive Operation) Operation to regulate the rectified output voltage at the level corresponding to the level of the output voltage reference signal, and/or to regulate the rectified output current at the level corresponding to the level of the output current reference signal.

3 . The resonant wireless power receiver circuit of claim 2 , wherein the switch control circuit is configured to operably control the first and the second multi-mode switches by the multi-mode switch control signal to operate in the Resonance Short Circuit Operation so as to limit a level of the AC resonant signal when the level of the rectified output voltage is larger than the rectified output voltage threshold and/or when the level of the rectified output current is larger than the rectified output current threshold, such that the level of the rectified output voltage is limited to be not larger than the rectified output voltage threshold, and/or the level of the rectified output current is limited to be not larger than the rectified output current threshold.

4 . The resonant wireless power receiver circuit of claim 1 , wherein the resonant circuit further includes an impedance matching circuit which includes one impedance matching capacitor coupled to the receiver coil in series or in parallel, or which includes two or more impedance matching capacitors coupled in series, or in parallel, or in a combination of parallel and series, and the two or more impedance matching capacitors being coupled to the receiver coil.

5 . The resonant wireless power receiver circuit of claim 2 , wherein the first rectifier device and the second rectifier device are configured as (A), (B), or (C):
(A) each of the first rectifier device and the second rectifier device including a diode, wherein the anodes and the cathodes of the diodes correspond to the current inflow nodes and the current outflow nodes of the first rectifier device and the second rectifier device respectively; (B) the first rectifier device including a third multi-mode switch and the second rectifier device including a forth multi-mode switch, wherein the feedback control circuit controls the third multi-mode switch and the forth multi-mode switch by the multi-mode switch control signal to operate in the Synchronous Rectifying Switching Operation; or (C) the first rectifier device and the second rectifier device being a combination of a diode and a third multi-mode switch, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the first rectifier device or the second rectifier device, and the feedback control circuit controls the third multi-mode switch by the multi-mode switch control signal to operate in the Synchronous Rectifying Switching Operation.

6 . The resonant wireless power receiver circuit of claim 1 , wherein each of the first and the second multi-mode switches includes a semiconductor switch.

7 . The resonant wireless power receiver circuit of claim 1 , wherein the bridge rectifier circuit further includes a first bypass diode and a second bypass diode, the first and the second multi-mode switches being connected to the first and the second bypass diode in parallel respectively.

8 . The resonant wireless power receiver circuit of claim 1 , wherein the switch controlled rectifier circuit further includes a rectifier device, and each of the rectifier device and the multi-mode switch has a current inflow node and a current outflow node;
wherein the multi-mode switch and the rectifier device are configured as (A) or (B): (A)

Assignees

• Richtek Technology Corp

Inventors

• Liu Kuo-Chi
• Wei Wei-Hsin

Classifications

• H02M7/219

  in a bridge configuration · CPC title

• H02J50/12 Primary

  of the resonant type · CPC title

• H02J5/005 Primary

  Electricity · mapped topic

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title

• H02M3/04

  by static converters · CPC title