RESONANT WIRELESS POWER RECEIVER CIRCUIT AND CONTROL CIRCUIT AND WIRELESS POWER CONVERSION METHOD THEREOF

• US 20160336811A1
• Filed: 05/13/2016
• Published: 11/17/2016
• Est. Priority Date: 05/15/2015
• Status: Active Grant

• Current Assignee: Richtek Technology Corporation (MediaTek, Inc.)
• Original Assignee: Richtek Technology Corporation (MediaTek, Inc.)
• Inventors: Liu, Kuo-Chi, Wei, Wei-Hsin
• Granted Patent: US 9,853,506 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: H02M 7/219 in a bridge configuration
• CPC Class Codes: Y02B 70/10 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

Abstract

The present invention provides a resonant wireless power receiver circuit, comprising: a resonant circuit for receiving a wireless power to generate a AC resonant signal which has an amplitude; a bridge rectifier circuit which includes a multi-mode switch, for rectifying the AC resonant signal to a rectifier output signal to drive a load, wherein the rectifier output signal includes a rectifier output voltage and a rectifier output current; 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 multi-mode switch to operate in a Conductive Operation at least for a partial time in a cycle period, such that the rectifier output voltage is substantially twice the amplitude, or the rectifier output voltage corresponds to an output voltage reference and/or the rectifier output voltage corresponds to an output current reference.

Claims

1. A resonant wireless power receiver circuit, comprising:

a resonant circuit, including;

a receiver circuit which includes at least a receiver coil; and

an impedance matching circuit which is coupled to the receiver circuit, including at least one impedance matching capacitor;

wherein the resonant circuit is 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, and the AC resonant signal includes an AC resonant voltage, and the AC resonant voltage has an amplitude;

a bridge 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 bridge rectifier circuit includes at least four rectifier devices, wherein each of the four rectifier devices has a current outflow node and a current inflow node, wherein the four rectifier devices include a first rectifier device, a second rectifier device, a third rectifier device, and a forth rectifier device, and the current outflow nodes of the third rectifier device and the forth rectifier device are connected to each other at a rectified output node, and the current inflow nodes of the first rectifier device and the second rectifier device are connected to each other at a ground node, and the current inflow node of the third rectifier device and the current outflow node of the first rectifier device are connected to each other at the negative resonant output node, and the current inflow node of the forth rectifier device and the current outflow node of the second rectifier device are connected to each other at the positive resonant output node, wherein at least one of the four rectifier devices is a multi-mode switch, wherein the impedance matching capacitor is connected in series between the receiver circuit and the bridge rectifier circuit; and

a feedback control circuit, configured to operably generate a multi-mode switch control signal for controlling the multi-mode switch to operate at least in a portion of time in the Conductive Operation according to a voltage feedback signal related to the rectified output voltage and/or a current feedback signal related to the rectified output current so as to achieve the following functions;

(A) such that the voltage level of the rectified output voltage is substantially twice the amplitude of the AC resonant voltage;

or

(B) 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.

2. The resonant wireless power receiver circuit of claim 1, wherein the feedback control circuit controls the multi-mode switch by the multi-mode switch control signal, such that the multi-mode switch operate in a time-divided combination of a Synchronous Rectifying Switching Operation, and a Conductive 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 four rectifier devices are configured as (A), or (B), or (C), or (D):

(A) the four rectifier devices include a multi-mode switch and three diodes, wherein the anode and the cathode of each of the three diodes correspond to the current inflow node and the current outflow node of each of the three diodes respectively, and the feedback control circuit controls the multi-mode switch by the multi-mode switch control signal;

(B) the four rectifier devices include four multi-mode switches, wherein the feedback control circuit controls the four multi-mode switches by the multi-mode switch control signal;

(C) the four rectifier devices include a combination of a diode and three multi-mode switches, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the diode respectively, and the feedback control circuit controls the three multi-mode switches by the multi-mode switch control signal;

(D) the four rectifier devices include a combination of two diode and two multi-mode switches, wherein the anode and the cathode of the two diodes correspond to the current inflow node and the current outflow node of the two diodes respectively, and the feedback control circuit controls the two multi-mode switches by the multi-mode switch control signal.

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

5. The resonant wireless power receiver circuit of claim 1, wherein the bridge rectifier circuit further includes one or plural bypass diodes of which the number corresponds to the number of the one or plural multi-mode diodes, and each of the multi-mode switches is connected to one individual diode of the one or plural bypass diodes in parallel respectively, and the anode and the cathode of each of the bypass diodes correspond to the current inflow node and the current outflow node of each of the multi-mode switches respectively.

6. The resonant wireless power receiver circuit of claim 1, further including an output capacitor which is connected between the rectified output node and the ground node, wherein when the level of the rectified output voltage is configured to be substantially twice the amplitude of the AC resonant voltage, the impedance capacitor is charged by the AC resonant voltage during a negative half wave voltage of AC resonant voltage, and the impedance capacitor charges the output capacitor during a positive half wave voltage of AC resonant voltage.

7. A resonant wireless power receiver circuit, comprising:

a resonant circuit, including;

a receiver circuit which includes at least a receiver coil; and

an impedance matching circuit which is coupled to the receiver circuit, including at least one impedance matching capacitor;

wherein the resonant circuit is 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, and the AC resonant signal includes

an AC resonant voltage, and the AC resonant voltage has

an amplitude;

a bridge 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 bridge rectifier circuit includes at least four rectifier devices, wherein each of the four rectifier devices has a current outflow node and a current inflow node, wherein the four rectifier devices include a first rectifier device, a second rectifier device, a third rectifier device, and a forth rectifier device, and the current outflow nodes of the third rectifier device and the forth rectifier device are connected to each other at a rectified output node, and the current inflow nodes of the first rectifier device and the second rectifier device are connected to each other at a ground node, and the current inflow node of the third rectifier device and the current outflow node of the first rectifier device are connected to each other at the negative resonant output node, and the current inflow node of the forth rectifier device and the current outflow node of the second rectifier device are connected to each other at the positive resonant output node, wherein at least one of the four rectifier devices is a multi-mode switch, wherein the impedance matching capacitor is connected in series between the receiver circuit and the bridge rectifier circuit; and

a control circuit, configured to operably generate a multi-mode switch control signal for controlling the multi-mode switch to operate in a Conductive Operation according to a mode selection signal, such that the voltage level of the rectified output voltage is substantially twice the amplitude of the AC resonant voltage.

8. The resonant wireless power receiver circuit of claim 7, further including an output capacitor which is connected between the rectified output node and the ground node, wherein when the level of the rectified output voltage is configured to be substantially twice the amplitude of the AC resonant voltage, the impedance capacitor is charged by the AC resonant voltage during a negative half wave voltage of AC resonant voltage, and the impedance capacitor charges the output capacitor during a positive half wave voltage of AC resonant voltage.

9. A feedback control circuit, configured to operably control a resonant wireless power receiver circuit which comprises:

a resonant circuit, including;

a receiver circuit which includes at least a receiver coil; and

an impedance matching circuit which is coupled to the receiver circuit, including at least one impedance matching capacitor;

wherein the resonant circuit is 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, and the AC resonant signal includes an AC resonant voltage, and the AC resonant voltage has an amplitude;

a bridge 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 bridge rectifier circuit includes at least four rectifier devices, wherein each of the four rectifier devices has a current outflow node and a current inflow node, wherein the four rectifier devices include a first rectifier device, a second rectifier device, a third rectifier device, and a forth rectifier device, and the current outflow nodes of the third rectifier device and the forth rectifier device are connected to each other at a rectified output node, and the current inflow nodes of the first rectifier device and the second rectifier device are connected to each other at a ground node, and the current inflow node of the third rectifier device and the current outflow node of the first rectifier device are connected to each other at the negative resonant output node, and the current inflow node of the forth rectifier device and the current outflow node of the second rectifier device are connected to each other at the positive resonant output node, wherein at least one of the four rectifier devices is a multi-mode switch, wherein the impedance matching capacitor is connected in series between the receiver circuit and the bridge rectifier circuit;

the feedback control circuit includes;

an error feedback circuit, configured to operably generate a voltage error feedback signal according to a voltage feedback signal related to the rectified output voltage and/or to generate a current error feedback signal according to a current feedback signal related to the rectified output current; and

a switch control circuit, configured to operably generate a multi-mode switch control signal for controlling the multi-mode switch to operate at least in a portion of time in the Conductive Operation according to a voltage feedback signal related to the rectified output voltage and/or a current feedback signal related to the rectified output current so as to achieve the following functions;

(A) such that the voltage level of the rectified output voltage is substantially twice the amplitude of the AC resonant voltage;

or

(B) 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.

10. The feedback control circuit of claim 9, wherein the feedback control circuit controls the multi-mode switch by the multi-mode switch control signal, such that the multi-mode switch operate in a time-divided combination of a Synchronous Rectifying Switching Operation, and a Conductive 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.

11. The feedback control circuit of claim 10, further including a synchronous control circuit which is configured to operably generate a synchronous control signal according to the rectified output signal and the AC resonant signal;

wherein the switch control circuit generates the multi-mode switch control signal further according to the synchronous control signal.

12. The feedback control circuit of claim 9, wherein the four rectifier devices are configured as (A), or (B), or (C), or (D):

(A) the four rectifier devices include a multi-mode switch and three diodes, wherein the anode and the cathode of each of the three diodes correspond to the current inflow node and the current outflow node of each of the three diodes respectively, and the feedback control circuit controls the multi-mode switch by the multi-mode switch control signal;

(B) the four rectifier devices include four multi-mode switches, wherein the feedback control circuit controls the four multi-mode switches by the multi-mode switch control signal;

(C) the four rectifier devices include a combination of a diode and three multi-mode switches, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the diode respectively, and the feedback control circuit controls the three multi-mode switches by the multi-mode switch control signal;

(D) the four rectifier devices include a combination of two diode and two multi-mode switches, wherein the anode and the cathode of the two diodes correspond to the current inflow node and the current outflow node of the two diodes respectively, and the feedback control circuit controls the two multi-mode switches by the multi-mode switch control signal.

13. The feedback control circuit of claim 10, wherein the four rectifier devices are configured as (A), or (B), or (C), or (D):

(A) the four rectifier devices include a multi-mode switch and three diodes, wherein the anode and the cathode of each of the three diodes correspond to the current inflow node and the current outflow node of each of the three diodes respectively, and the feedback control circuit controls the multi-mode switch by the multi-mode switch control signal;

(B) the four rectifier devices include four multi-mode switches, wherein the feedback control circuit controls the four multi-mode switches by the multi-mode switch control signal;

(C) the four rectifier devices include a combination of a diode and three multi-mode switches, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the diode respectively, and the feedback control circuit controls the three multi-mode switches by the multi-mode switch control signal;

(D) the four rectifier devices include a combination of two diode and two multi-mode switches, wherein the anode and the cathode of the two diodes correspond to the current inflow node and the current outflow node of the two diodes respectively, and the feedback control circuit controls the two multi-mode switches by the multi-mode switch control signal.

14. The feedback control circuit of claim 9, wherein each of the multi-mode switches includes a semiconductor switch.

15. The feedback control circuit of claim 9, wherein the bridge rectifier circuit further includes one or plural bypass diodes of which the number corresponds to the number of the one or plural multi-mode diodes, and each of the multi-mode switches is connected to one individual diode of the one or plural bypass diodes in parallel respectively, and the anode and the cathode of each of the bypass diodes correspond to the current inflow node and the current outflow node of each of the multi-mode switches respectively.

16. A resonant wireless power conversion method, wherein a resonant circuit receives a wireless power and generates 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, and the resonant circuit includes an impedance matching capacitor;

the resonant wireless power conversion method includes;

controlling a bridge rectifier circuit to 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 bridge rectifier circuit includes at least four rectifier devices, wherein each of the four rectifier devices has a current outflow node and a current inflow node, wherein the four rectifier devices include a first rectifier device, a second rectifier device, a third rectifier device, and a forth rectifier device, and the current outflow nodes of the third rectifier device and the forth rectifier device are connected to each other at a rectified output node, and the current inflow nodes of the first rectifier device and the second rectifier device are connected to each other at a ground node, and the current inflow node of the third rectifier device and the current outflow node of the first rectifier device are connected to each other at the negative resonant output node, and the current inflow node of the forth rectifier device and the current outflow node of the second rectifier device are connected to each other at the positive resonant output node, wherein at least one of the four rectifier devices is a multi-mode switch;

wherein the step of controlling a bridge rectifier circuit to convert the AC resonant signal to generate a rectified output signal includes;

generating a multi-mode switch control signal according to a voltage feedback signal related to the rectified output voltage and/or a current feedback signal related to the rectified output current; and

controlling the multi-mode switch to operate at least in a portion of time in the Conductive Operation by the multi-mode switch control signal, so as to achieve the following functions;

(A) such that the voltage level of the rectified output voltage is substantially twice the amplitude of the AC resonant voltage;

or

(B) 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.

17. The resonant wireless power conversion method of claim 16, wherein the step of regulating 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 includes:

controlling the multi-mode switch by the multi-mode switch control signal, such that the multi-mode switch operate in a time-divided combination of a Synchronous Rectifying Switching Operation, and a Conductive Operation.

18. The resonant wireless power conversion method of claim 16, wherein the step of generating the multi-mode switch control signal further includes:

generating a synchronous control signal according to the rectified output signal and the AC resonant signal; and

generating the multi-mode switch control signal according to the synchronous control signal.

19. The resonant wireless power conversion method of claim 16, wherein the four rectifier devices include (A), or (B), or (C), or (D):

(A) the four rectifier devices include a multi-mode switch and three diodes, wherein the anode and the cathode of each of the three diodes correspond to the current inflow node and the current outflow node of each of the three diodes respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the multi-mode switch by the multi-mode switch control signal;

(B) the four rectifier devices include four multi-mode switches, wherein the step of controlling the bridge rectifier circuit includes controlling the four multi-mode switches by the multi-mode switch control signal;

(C) the four rectifier devices include a combination of a diode and three multi-mode switches, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the diode respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the three multi-mode switches by the multi-mode switch control signal;

(D) the four rectifier devices include a combination of two diode and two multi-mode switches, wherein the anode and the cathode of the two diodes correspond to the current inflow node and the current outflow node of the two diodes respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the two multi-mode switches by the multi-mode switch control signal.

20. The resonant wireless power conversion method of claim 17, wherein the four rectifier devices include (A), or (B), or (C), or (D):

(A) the four rectifier devices include a multi-mode switch and three diodes, wherein the anode and the cathode of each of the three diodes correspond to the current inflow node and the current outflow node of each of the three diodes respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the multi-mode switch by the multi-mode switch control signal;

(B) the four rectifier devices include four multi-mode switches, wherein the step of controlling the bridge rectifier circuit includes controlling the four multi-mode switches by the multi-mode switch control signal;

(C) the four rectifier devices include a combination of a diode and three multi-mode switches, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the diode respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the three multi-mode switches by the multi-mode switch control signal;

(D) the four rectifier devices include a combination of two diode and two multi-mode switches, wherein the anode and the cathode of the two diodes correspond to the current inflow node and the current outflow node of the two diodes respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the two multi-mode switches by the multi-mode switch control signal.

21. The resonant wireless power conversion method of claim 18, wherein the four rectifier devices include (A), or (B), or (C), or (D):

(A) the four rectifier devices include a multi-mode switch and three diodes, wherein the anode and the cathode of each of the three diodes correspond to the current inflow node and the current outflow node of each of the three diodes respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the multi-mode switch by the multi-mode switch control signal;

(B) the four rectifier devices include four multi-mode switches, wherein the step of controlling the bridge rectifier circuit includes controlling the four multi-mode switches by the multi-mode switch control signal;

(C) the four rectifier devices include a combination of a diode and three multi-mode switches, wherein the anode and the cathode of the diode correspond to the current inflow node and the current outflow node of the diode respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the three multi-mode switches by the multi-mode switch control signal;

(D) the four rectifier devices include a combination of two diode and two multi-mode switches, wherein the anode and the cathode of the two diodes correspond to the current inflow node and the current outflow node of the two diodes respectively, wherein the step of controlling the bridge rectifier circuit includes controlling the two multi-mode switches by the multi-mode switch control signal.

22. The resonant wireless power conversion method of claim 16, wherein each of the multi-mode switches includes a semiconductor switch.

23. The resonant wireless power conversion method of claim 16, wherein the bridge rectifier circuit further includes one or plural bypass diodes of which the number corresponds to the number of the one or plural multi-mode diodes, and each of the multi-mode switches is connected to one individual diode of the one or plural bypass diodes in parallel respectively, and the anode and the cathode of each of the bypass diodes correspond to the current inflow node and the current outflow node of each of the multi-mode switches respectively.

24. The resonant wireless power conversion method of claim 16, wherein the rectified output voltage is the voltage across an output capacitor which is connected between the rectified output node and the ground node, wherein when the level of the rectified output voltage is configured to be substantially twice the amplitude of the AC resonant voltage, the impedance capacitor is charged by the AC resonant voltage during a negative half wave voltage of AC resonant voltage, and the impedance capacitor charges the output capacitor during a positive half wave voltage of AC resonant voltage.