Wireless charging circuit

Abstract

The wireless charging circuit includes: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies the AC voltage received from the power receiving circuit and outputs a rectified voltage; an adjustment circuit that outputs a charging voltage for charging the battery using the rectified voltage; an overvoltage protection circuit connected in parallel between the rectifier circuit and the regulation circuit; and a controller detecting the rectified voltage and controlling the overvoltage protection circuit. The overvoltage protection circuit comprises a first overvoltage protection circuit and a second overvoltage protection circuit. By separating the on-hold time of the first overvoltage protection circuit and the second overvoltage protection circuit, the wireless charging circuit is effectively protected from overvoltage, and damage to the circuit due to heat generation is prevented.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of Korean Patent Application No. 10-2023-0098353 filed in the Korean Intellectual Property Office on July 27, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments of the inventive concept relate to a wireless charging circuit. Background Art

[0004] An electronic device generally includes a battery that supplies a power voltage for operation, and a charging circuit that charges the battery using power supplied from an external source. Battery charging methods can be divided into a wired charging method that charges the battery by directly connecting a charging terminal to the electronic device, and a wireless charging method that charges the battery by using power output to the charging pad when the electronic device approaches the charging pad without connecting the charging terminal. In the wireless charging method, when the electronic device is not accurately aligned with the wireless charging pad, an overvoltage may occur in the wireless charging circuit in the electronic device. Summary of the invention

[0005] Embodiments of the inventive concept prevent damage to a battery and a wireless charging circuit by including a first overvoltage protection circuit having a current source and a second overvoltage protection circuit having a resistor and by alternately turning the first overvoltage protection circuit and the second overvoltage protection circuit on and off to effectively generate power loss when an overvoltage occurs.

[0006] According to an embodiment, a wireless charging circuit includes: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies an AC voltage received from the power receiving circuit and outputs a rectified voltage; a regulating circuit that outputs a charging voltage for charging a battery using the rectified voltage; an overvoltage protection circuit that is connected in parallel between the rectifier circuit and the regulating circuit; and a controller that detects the rectified voltage and controls the overvoltage protection circuit. The overvoltage protection circuit includes a first overvoltage protection circuit and a second overvoltage protection circuit. The second overvoltage protection circuit is turned off when the first overvoltage protection circuit is turned on, and the second overvoltage protection circuit is turned on when the first overvoltage protection circuit is turned off.

[0007] According to an embodiment, a wireless charging circuit includes: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies an AC voltage received from the power receiving circuit and outputs a rectified voltage; a regulating circuit that outputs a charging voltage for charging a battery using the rectified voltage; an overvoltage protection circuit that is connected in parallel between the rectifier circuit and the regulating circuit; and a controller that detects the rectified voltage and controls the overvoltage protection circuit. The overvoltage protection circuit includes a first overvoltage protection circuit and a second overvoltage protection circuit. The first overvoltage protection circuit is turned on before the second overvoltage protection circuit, and at least one of the first overvoltage protection circuit and the second overvoltage protection circuit is repeatedly turned on and off.

[0008] According to an embodiment, a wireless charging circuit includes: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies an AC voltage received from the power receiving circuit and outputs a rectified voltage; a regulating circuit that outputs a charging voltage for charging a battery using the rectified voltage; an overvoltage protection circuit that includes at least one first overvoltage protection circuit and at least one second overvoltage protection circuit, the at least one first overvoltage protection circuit being connected in parallel between the rectifier circuit and the regulating circuit and including a current source, the at least one second overvoltage protection circuit being connected in parallel between the rectifier circuit and the regulating circuit and including a resistor; and a controller that detects the rectified voltage and controls the overvoltage protection circuit. The controller turns on the first overvoltage protection circuit when the overvoltage protection circuit meets a first operating condition, turns off the first overvoltage protection circuit and turns on the second overvoltage protection circuit when the overvoltage protection circuit meets a second operating condition, and turns on one of the first overvoltage protection circuit and the second overvoltage protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a diagram of a wireless charging system according to an embodiment.

[0010] Figure 2 is a block diagram of a wireless charging system according to an embodiment.

[0011] Figure 3 is a detailed block diagram of a wireless charging system according to an embodiment.

[0012] Figure 4 is a schematic circuit diagram of a wireless charging system according to an embodiment.

[0013] Figure 5 Graphs showing changes in rectified voltage and operation of switches in an overvoltage protection circuit as a function of time are shown according to an embodiment.

[0014] Figures 6 to 12is a graph illustrating the operation of a switch in an overvoltage protection circuit as a function of time according to an embodiment.

[0015] Fig.13 is a schematic circuit diagram of an overvoltage protection circuit according to an embodiment.

[0016] Fig.14 The diagram shows the Fig.13 A graph of the operation of a switch in an overvoltage protection circuit as a function of time.

[0017] Fig.15 is a graph of temperature variation of a wireless charging circuit and a resistor as a function of time when an overvoltage protection circuit operates according to an embodiment.

[0018] Fig.16 is a block diagram of an electronic device according to an embodiment.

[0019] Fig.17 is a flow chart of an operation process of an overvoltage protection circuit according to an embodiment.

[0020] Fig.18 is a flow chart of an operation process of an overvoltage protection circuit according to an embodiment. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0022] Figure 1 is a diagram of a wireless charging system according to an embodiment.

[0023] Reference Figure 1 In an embodiment, the wireless charging system 1 includes a wireless power transmitter 10 and a wireless power receiver 20. Figure 1 In the embodiment shown in , there may be one wireless power receiver 20, but the embodiment is not necessarily limited thereto. The wireless power receiver 20 may be implemented as a mobile communication terminal, a PDA, a PMP, a smart phone, etc., and include a wireless charging circuit.

[0024] The wireless power transmitter 10 is electrically connected to the wireless power receiver 20. In an embodiment, the wireless power transmitter 10 transmits wireless power to the wireless power receiver 20 in the form of electromagnetic waves. In addition, the wireless power transmitter 10 can perform two-way communication with the wireless power receiver 20. For example, the wireless power receiver 20 transmits a signal requesting wireless power transmission, information for wireless power reception, state information of the wireless power receiver 20, control information of the wireless power transmitter 10, etc. to the wireless power transmitter 10. The wireless power transmitter 10 transmits power to the wireless power receiver 20 based on the received information.

[0025] The wireless power receiver 20 receives wireless power from the wireless power transmitter 10 and charges the battery in the wireless power receiver 20. The wireless power transmitter 10 and the wireless power receiver 20 should be placed in a desired position to be properly charged. For example, when the wireless power transmitter 10 is not placed in a desired position, the wireless power receiver 20 receives more power than requested.

[0026] An overvoltage may occur in the wireless charging circuit in the wireless power receiver 20, and the circuit is protected by causing power loss through the overvoltage protection circuit. In an embodiment, the overvoltage protection circuit includes a current source and a resistor connected in parallel, and each of the current source and the resistor is turned on alternately. Therefore, the wireless charging circuit is protected from overvoltage by causing effective power loss, and the internal circuit in the wireless power receiver 20 is protected from heat generated by the resistor.

[0027] Figure 2 is a block diagram of a wireless charging system according to an embodiment.

[0028] In an embodiment, the wireless charging system 50 includes a wireless power transmitter 60 and a wireless power receiver 70. The wireless power transmitter 60 includes a power transmitter 61, a controller 62, and a communication unit 63. The wireless power receiver 70 includes a power receiver 71, a controller 72, a communication unit 73, and a battery 74.

[0029] The power transmitter 61 transmits the power requested by the wireless power receiver 70, and wirelessly transmits the power to the power receiver 71. For example, the power transmitter 61 supplies and transmits power in the form of an alternating current (AC) waveform, and converts the power of a direct current (DC) waveform into an AC waveform while supplying power in the form of a DC waveform, and thus also transmits power in the form of an AC waveform. In addition, the power transmitter 61 is implemented in the form of a built-in battery, a power receiving interface, and a receiver that receives power from the outside and supplies power to other components. In an embodiment, the power transmitter 61 transmits the AC waveform to the power receiver 71 in the form of an electromagnetic wave.

[0030] The communication unit 63 of the wireless power transmitter 60 communicates with the communication unit 73 of the wireless power receiver 70, and performs communication, for example, using at least one of near field communication (NFC), infrared communication, visible light communication, etc. The communication unit 63 transmits a signal related to information of the wireless power transmitter 60. The communication unit 63 receives the requested power information from the wireless power receiver 70, and for example, the communication unit 63 receives the remaining battery amount, the number of charging times, the usage amount, the battery capacity, the battery percentage, etc. of the wireless power receiver 70.

[0031] The controller 62 of the wireless power transmitter 60 controls the overall operation of the wireless power transmitter 60. For example, the controller 62 is implemented in the form of one of a CPU, a microprocessor, and a minicomputer. The controller 62 calculates the power information received by the communication unit 63, and controls whether the power transmitter 61 generates power, the magnitude of the generated power, the power transmission time, etc.

[0032] The power receiver 71 wirelessly receives power from the power transmitter 61. The power receiver 71 receives power in an alternating current form and charges the battery 74 through one or more of a rectifier circuit, a regulating circuit, etc. The communication unit 73 of the wireless power receiver 70 transmits the requested power information to the communication unit 63, and the controller 72 controls the overall operation of the wireless power receiver 70.

[0033] The power receiver 71 includes an overvoltage protection circuit having a current source and a resistor connected in parallel, and the controller 72 controls the overvoltage protection circuit. When the wireless power receiver 70 is repeatedly attached to and detached from the wireless power transmitter 60 in a short period of time, the power receiver 71 may receive more power than requested from the wireless power transmitter 60. Overvoltage may occur in the power receiver 71, and power should be leaked through the overvoltage protection circuit. According to an embodiment of the inventive concept, the controller 72 alternately connects the resistor and the current source in the overvoltage protection circuit, thereby leaking a certain amount of power. Therefore, the power receiver 71 is effectively protected from overvoltage, and the power leakage efficiency is maintained by reducing the heat generated by the resistor due to power leakage.

[0034] Figure 3 is a detailed block diagram of a wireless charging system according to an embodiment.

[0035] Reference Figure 3 In an embodiment, the wireless charging system 100 includes a wireless power transmitter 200 and a wireless power receiver 300. The wireless power transmitter 200 includes a power transmitter 210, and control and communication units 220 and 230, and the power transmitter 210 includes a power transmission circuit 211, a rectifier circuit 212, and a power generation circuit 213. The wireless power receiver 300 includes a power receiver 310, control and communication units 320 and 330, and a battery 340, and the power receiver 310 includes a power receiving circuit 311, a rectifier circuit 312, an overvoltage protection circuit 313, a regulation circuit 314, and a charger 315.

[0036] The control and communication units 220 and 230 of the wireless power transmitter 200 perform bidirectional communication with the control and communication units 320 and 330 of the wireless power receiver 300. The communication unit 230 receives power information from the wireless power receiver 300, and the control unit 220 controls the power transmitter 210 based on the received power information.

[0037] The wireless power transmitter 200 generates power and wirelessly transmits the power to the wireless power receiver 300. For the embodiment, the power generation circuit 213 outputs AC power having a voltage and frequency specified for the wireless power receiver 300. The AC power is rectified by the rectifier circuit 212, and, for example, the rectifier circuit 212 outputs rectified power obtained by single-phase full-wave rectification of the AC power. The power transmission circuit 211 transmits the rectified power to the wireless power receiver 300 by performing impedance matching with the power receiving circuit 311.

[0038] The wireless power receiver 300 wirelessly receives power from the wireless power transmitter 200 and outputs an AC voltage. In an embodiment, the power receiving circuit 311 outputs single-phase full-wave rectified power. The rectifier circuit 312 outputs a rectified voltage by rectifying the AC voltage received from the power receiving circuit 311. The regulating circuit 314 outputs a charging voltage for charging the battery using the rectified voltage, and the charging voltage has a preset voltage value for charging the battery 340. The charger 315 charges the battery 340 using the charging voltage. The power receiver 310 and the battery 340 are controlled by the control unit 320.

[0039] According to an embodiment, the power receiver 310 includes an overvoltage protection circuit 313 connected in parallel between the rectifier circuit 312 and the regulating circuit 314. The overvoltage protection circuit 313 includes at least one current source and at least one resistor. When the rectified voltage is greater than the level required by the wireless power receiver 300, the overvoltage protection circuit 313 leaks power to protect the power receiver 310. For example, at least one current source and at least one resistor of the overvoltage protection circuit 313 are alternately connected to the circuit. Therefore, the internal temperature of the power receiver 310 and the resistor can be maintained within a predetermined range. The operating standard of the overvoltage protection circuit 313 is the rectified voltage or internal temperature of the power receiver 310.

[0040] Figure 4 is a schematic circuit diagram of a wireless charging system according to an embodiment.

[0041] Reference Figure 4 In an embodiment, the wireless charging system 400 may include a power transmitter 500, a power receiver 600, and a battery 630. The battery 630 may be included in the power receiver 600.

[0042] The power transmitter 500 generates power and wirelessly transmits the power to the power receiver 600. The power transmitter 500 includes a power generation circuit 510, a rectifier circuit 520, and a power transmission circuit 530. In an embodiment, the power generation circuit 510 outputs AC power having a voltage and frequency specified for the wireless power receiver. For example, the power generation circuit 510 includes an AC voltage source. The rectifier circuit 520 rectifies the AC power received from the power generation circuit 510. In an embodiment, the rectifier circuit 520 is implemented in the form of a bridge diode (S1-S4), and outputs rectified power obtained by single-phase full-wave rectification of AC power.

[0043] The power transmission circuit 530 performs impedance matching and wireless power transmission functions. In an embodiment, the power transmission circuit 530 includes a first capacitor C1 and a first inductor L1, and the first capacitor C1 and the first inductor L1 are connected in series. The controller of the wireless power transmitter adjusts the values ​​of the first capacitor C1 and the first inductor L1 of the power transmission circuit 530 so that power is effectively transmitted. For example, the power transmission circuit 530 and the power receiving circuit 611 are implemented as resonant circuits having the same resonant frequency. Therefore, the power transmission circuit 530 transmits the rectified power to the power receiving circuit 611 in the form of electromagnetic waves.

[0044] The power receiver 600 charges the battery 630 using the power received from the power transmitter 500. The power receiver 600 includes a wireless charging circuit 610 and a charger 620, and the wireless charging circuit 610 includes a power receiving circuit 611, a rectifier circuit 612, an overvoltage protection circuit 613, and a regulating circuit 614.

[0045] The power receiving circuit 611 is impedance matched with the power transmitting circuit 530 to wirelessly receive power. The power receiving circuit 611 includes a second inductor L2, a second capacitor C2, and a third capacitor C3. The second inductor L2 and the second capacitor C2 are connected in series, and are connected in parallel with the third capacitor C3. The power received by the power receiving circuit 611 is obtained by single-phase full-wave rectification of the AC power in the power transmitter 500, and the power receiving circuit 611 outputs an AC voltage.

[0046] The rectifier circuit 612 rectifies the power received by the power receiving circuit 611 into a direct current, and the rectifier circuit 612 outputs a rectified voltage V RECT For example, the rectifier circuit 612 is implemented in the form of a bridge diode S5-S8.

[0047] The overvoltage protection circuit 613 performs an overvoltage protection (OVP) operation to prevent an overvoltage from occurring in the wireless charging circuit 610. The controller 615 in the wireless power receiver may detect the rectified voltage V received from the rectifier circuit 612. RECT and the temperature of the wireless charging circuit 610. The overvoltage protection circuit 613 performs an overvoltage protection operation using the detection result, and the controller 615 controls the overvoltage protection circuit 613.

[0048] According to an embodiment, the overvoltage protection circuit 613 is connected in parallel between the rectifier circuit 612 and the regulating circuit 614. The overvoltage protection circuit 613 includes a first overvoltage protection circuit 613A and a second overvoltage protection circuit 613B. The first overvoltage protection circuit 613A includes a current source A and a first switch OVP_SW1 connected in series. The second overvoltage protection circuit 613B includes a resistor R and a second switch OVP_SW2 connected in series. Figure 4 Unlike that shown in , the resistor R is located outside the area of ​​the overvoltage protection circuit 613.

[0049] According to an embodiment, when the first overvoltage protection circuit 613A is turned on, the second overvoltage protection circuit 613B is turned off, and when the first overvoltage protection circuit 613A is turned off, the second overvoltage protection circuit 613B is turned on. For example, when the overvoltage protection circuit 613 satisfies the first operating condition defined below, the controller 615 turns on the first overvoltage protection circuit 613A. When the overvoltage protection circuit 613 satisfies the second operating condition defined below, the controller 615 turns off the first overvoltage protection circuit 613A and turns on the second overvoltage protection circuit 613B. For example, the controller 615 only turns on one of the first overvoltage protection circuit 613A and the second overvoltage protection circuit 613B.

[0050] The first operating condition refers to when the rectified voltage V RECT is greater than or equal to the first threshold voltage or the temperature of the wireless charging circuit is greater than or equal to the first threshold temperature. The second operating condition refers to when the rectified voltage V RECT When the rectified voltage V of the wireless charging circuit is greater than or equal to the second threshold voltage or the temperature of the wireless charging circuit is equal to or greater than the second threshold temperature. The second threshold voltage is greater than the first threshold voltage, and the second threshold temperature is higher than the first threshold temperature. In an embodiment, the controller 615 detects the rectified voltage V of the wireless charging circuit. RECT The controller 615 controls the overvoltage protection circuit 613 according to the first operating condition and the second operating condition, and the overvoltage protection circuit 613 outputs the overvoltage protection rectified voltage V RECT '.

[0051] The first overvoltage protection circuit 613A leaks a first current I1 when turned on, and the second overvoltage protection circuit 613B leaks a second current I2 when turned on. According to an embodiment, the magnitude of the second current I2 is greater than the magnitude of the first current I1, and the amount of power leaked through the second overvoltage protection circuit 613B is greater than the amount of power leaked through the first overvoltage protection circuit 613A. For example, the power supplied to the regulating circuit 614 is less than the power output by the rectifier circuit 612, and for example, the power supplied to the regulating circuit 614 when the second overvoltage protection circuit 613B is turned on is less than the power supplied to the regulating circuit 614 when the first overvoltage protection circuit 613A is turned on.

[0052] The regulation circuit 614 outputs the rectified voltage V using an overvoltage protection RECT 'The charging voltage V for charging the battery 630 CRG The regulation circuit 614 includes an AC / DC converter or a Figure 4 The low voltage drop circuit shown in the figure includes a switch (Q1), a current sensor and a resistor. CRG When the level of V is maintained at a specific value, the battery 630 can be stably charged. The regulating circuit 614 converts the overvoltage protection rectified voltage V RECT 'Converted to a specific value for charging the battery 630, and output the conversion result - charging voltage V CRG The charger 620 uses a charging voltage V CRG The battery 630 is charged.

[0053] When the first overvoltage protection circuit 613A is turned on, the temperature of the wireless charging circuit 610 increases, and when the second overvoltage protection circuit 613B is turned on, the temperature of the resistor R increases. According to an embodiment, the first overvoltage protection circuit 613A and the second overvoltage protection circuit 613B are alternately turned on and off to perform an overvoltage protection operation. For example, by repeatedly turning on and off, the temperature of the wireless charging circuit 610 and the resistor R can be maintained within a predetermined range. Therefore, damage to the wireless charging circuit 610 due to heat generation can be prevented, and the efficiency of the overvoltage protection operation of the resistor R can be maintained.

[0054] Figure 5 Graphs showing changes in rectified voltage and operation of switches in an overvoltage protection circuit as a function of time are shown according to an embodiment.

[0055] The wireless power receiver includes a wireless charging circuit and a controller, and wirelessly receives power from the wireless power transmitter to charge the built-in battery. The wireless charging circuit includes a power receiving circuit, a rectifier circuit, a regulating circuit, and an overvoltage protection circuit connected in parallel between the rectifier circuit and the regulating circuit. The rectifier circuit outputs a rectified voltage V RECT .

[0056] Reference Figure 5 A first graph showing a rectified voltage V when the wireless power receiver wirelessly receives power according to an embodiment RECT As a function of time. When the wireless power receiver starts to receive power, the rectified voltage V RECT Increase. Rectified voltage V RECT At the first time t1, the rectified voltage V increases to the first threshold voltage V1, and at the second time t2, the rectified voltage V increases to the second threshold voltage V2. RECT Maintained at the second threshold voltage V2.

[0057] The overvoltage protection circuit includes a first overvoltage protection circuit and a second overvoltage protection circuit, the first overvoltage protection circuit includes a current source and a first switch OVP_SW1, and the second overvoltage protection circuit includes a resistor R and a second switch OVP_SW2. When the first switch OVP_SW1 is closed, the first overvoltage protection circuit is turned on, and when the second switch OVP_SW2 is closed, the second overvoltage protection circuit is turned on.

[0058] Reference Figure 5 The second graph and Figure 5 In the third graph, when the first switch OVP_SW1 is closed, the second switch OVP_SW2 is opened. When the first switch OVP_SW1 is opened, the second switch OVP_SW2 is closed. For example, when the first overvoltage protection circuit is turned on, the second overvoltage protection circuit is turned off, and when the first overvoltage protection circuit is turned off, the second overvoltage protection circuit is turned on. Therefore, the turn-on time (t1, t3, ...) of the first overvoltage protection circuit is the same as the turn-off time (t1, t3, ...) of the second overvoltage protection circuit, and the turn-off time (t2, t4, ...) of the first overvoltage protection circuit is the same as the turn-on time (t2, t4, ...) of the second overvoltage protection circuit.

[0059] Reference Figure 5 , the first switch OVP_SW1 and the second switch OVP_SW2 are both disconnected until the rectified voltage V RECT Before the first time t1 when the first threshold voltage V1 is reached. For example, both the first overvoltage protection circuit and the second overvoltage protection circuit remain in the off state until before the first time t1.

[0060] When the rectified voltage V RECT When the voltage increases to the first threshold voltage V1, the first switch OVP_SW1 is closed and the first overvoltage protection circuit is turned on. Figure 5 In the embodiment shown in , the first overvoltage protection circuit is turned on at the first time t1. On the other hand, since the second switch OVP_SW2 is still turned off, the second overvoltage protection circuit remains turned off for a period of time after the first time t1.

[0061] When the rectified voltage V RECT During the time when the voltage is greater than or equal to the first threshold voltage V1 and less than the second threshold voltage V2, the first overvoltage protection circuit remains in the on state and the second overvoltage protection circuit remains in the off state. For example, during the first on-holding time t of the first overvoltage protection circuit ON11 During this period, the second overvoltage protection circuit is turned off, and the rectified voltage V RECT Increase.

[0062] When the rectified voltage V RECT At the second time t2 when the second threshold voltage V2 is reached, the first switch OVP_SW1 is turned off, and the first overvoltage protection circuit is changed to an off state. In addition, the second switch OVP_SW2 is closed at the second time t2, and the second overvoltage protection circuit is changed to an on state. For example, at the second time t2, the first overvoltage protection circuit is turned off and the second overvoltage protection circuit is turned on.

[0063] After the second time t2, the first switch OVP_SW1 and the second switch OVP_SW2 are alternately opened and closed. For example, the first overvoltage protection circuit and the second overvoltage protection circuit repeat the on-operation and the off-operation. Therefore, the rectified voltage V RECT is limited to not exceed the second threshold voltage V2.

[0064] For example, at the third time t3, the first switch OVP_SW1 is closed, and the first overvoltage protection circuit is changed to the on state. In addition, at the third time t3, the second switch OVP_SW2 is opened again, and the second overvoltage protection circuit is changed to the off state. For example, at the third time t3, the first overvoltage protection circuit is turned on and the second overvoltage protection circuit is turned off.

[0065] Since the first overvoltage protection circuit and the second overvoltage protection circuit are repeatedly turned on and off, the wireless charging circuit and the resistor are adjusted not to exceed a predetermined temperature, thereby preventing damage to the wireless charging circuit and the resistor due to high temperature.

[0066] Figures 6 to 12is a graph illustrating the operation of a switch in an overvoltage protection circuit as a function of time according to an embodiment.

[0067] The overvoltage protection circuit includes a first overvoltage protection circuit including a current source and a first switch OVP_SW1 and a second overvoltage protection circuit including a resistor and a second switch OVP_SW2. At least one of a period and a time when the first and second switches OVP_SW1 and OVP_SW2 are turned off may be set differently.

[0068] For example, refer to Figures 6 to 12 , the first overvoltage protection circuit is turned on before the second overvoltage protection circuit, and at least one of the first overvoltage protection circuit and the second overvoltage protection circuit is repeatedly turned on and off. Figure 5 When compared with the embodiment shown in Figures 6 to 12 In the embodiment shown in , the turn-on time of the first overvoltage protection circuit and the turn-off time of the second overvoltage protection circuit are inconsistent, and the turn-off time of the first overvoltage protection circuit and the turn-on time of the second overvoltage protection circuit are inconsistent.

[0069] Reference Figures 6 to 10 , the first switch OVP_SW1 repeats the opening operation and the closing operation at regular intervals. For example, the first overvoltage protection circuit is repeatedly turned on and off. Figures 6 to 10 The detailed operation of the first switch OVP_SW1 shown in FIG. Figure 5 The operation of the first switch OVP_SW1 shown in FIG. 1 is substantially similar. For example, the on-hold time (t ON11 ,t ON12 , ...) is equal to the turn-off holding time of the first overvoltage protection circuit (t OFF11 ,t OFF12 ,……).

[0070] Reference Figure 6 and Figure 7 , at the first time t1, the first switch OVP_SW1 is closed before the second switch OVP_SW2. At the second time t2, the second switch OVP_SW2 is closed and the first switch OVP_SW1 is opened. For example, at the second time t2, the second overvoltage protection circuit is turned on and the first overvoltage protection circuit is turned off.

[0071] according to Figure 6 In the embodiment shown in FIG. 1 , the second switch OVP_SW2 remains in the closed state after the second time t2. The first on-holding time t ON21 Longer than the total on-hold time (t ON11 ,tON12 For example, the total turn-off holding time of the second overvoltage protection circuit is shorter than the total turn-off holding time of the first overvoltage protection circuit (t OFF11 ,t OFF12 ,... and...). exist Figure 6 In the embodiment shown in , since the second switch OVP_SW2 remains closed after the second time t2, the wireless charging circuit is strongly protected from the power leaked through the second overvoltage protection circuit. Figure 5 Compared with the embodiment shown in Figure 6 The heat generated by the resistor in the second overvoltage protection circuit shown in FIG. Figure 5 The heat, and therefore power leakage efficiency, of the embodiment shown in FIG. 5 is relatively low.

[0072] according to Figure 7 The embodiment shown in Figure 6 Unlike the embodiment shown in , the second switch OVP_SW2 repeats the opening operation and the closing operation at regular intervals. For example, the second overvoltage protection circuit repeats the turning-on operation and the turning-off operation. For example, the on-holding time (t ON21 ,t ON22 , ...) is shorter than the turn-off holding time (t OFF21 ,t OFF22 ,……).

[0073] exist Figure 7 In the embodiment shown in , the off time of the second overvoltage protection circuit is inconsistent with the on time (t3, t5, ...) of the first overvoltage protection circuit. For example, the total off holding time (t OFF21 ,t OFF22 , ...) is longer than the total turn-off holding time (t OFF11 ,t OFF12 In addition, the turn-off holding time (t OFF21 ,t OFF22 , ...) and the first overvoltage protection circuit off holding time (t OFF11 ,t OFF12 For example, the first off-hold time t of the second overvoltage protection circuit is OFF21 A portion of the first overvoltage protection circuit and the first off-hold time t OFF11 By overlapping the off-hold time of the first overvoltage protection circuit and the second overvoltage protection circuit, the heat generation of the wireless charging circuit and the resistor can be more effectively reduced, thereby improving the efficiency of overvoltage protection.

[0074] Reference Figures 8 to 10 , the first switch OVP_SW1 is closed at the first time t1 before the second switch OVP_SW2. Figure 6 and Figure 7 Unlike the embodiment shown in , the closing time of the second switch OVP_SW2 is inconsistent with the opening time of the first switch OVP_SW1. For example, the turning-on time of the first overvoltage protection circuit is inconsistent with the turning-off time of the second overvoltage protection circuit, and the turning-off time of the first overvoltage protection circuit is inconsistent with the turning-on time of the second overvoltage protection circuit.

[0075] according to Figure 8 In the embodiment shown in FIG. 1 , the on-holding time (t ON11 ,t ON12 , ...) is longer than the on-hold time (t ON21 ,t ON22 , ...), and is shorter than the turn-off holding time (t OFF21 ,t OFF22 , ...). The off-holding time of the second overvoltage protection circuit overlaps with each of the adjacent off-holding times of the first overvoltage protection circuit. For example, the first off-holding time t of the second overvoltage protection circuit OFF21 A portion of the first overvoltage protection circuit and the first off-hold time t OFF11 and the second off-hold time t OFF12 Overlap. Figure 7 Compared with the second switch OVP_SW2 shown in FIG, due to the on-hold time t ON21 ,t ON22 , ... are shortened, so the amount of current leakage through the second overvoltage protection circuit is reduced, but the performance of the second overvoltage protection circuit is protected by effectively reducing the temperature of the resistor.

[0076] according to Fig. 9 In the embodiment shown in , the second switch OVP_SW2 is not closed at the second time t2 and the second switch OVP_SW2 is not opened at the third time t3. For example, the on-holding time (t ON21 ,t ON22 , ...) and the on-holding time (t ON11 ,t ON12 In addition, the turn-off holding time (t OFF21 ,t OFF22 , ...) and the first overvoltage protection circuit off holding time (t OFF11 ,t OFF12, ...) overlap. During the on-hold time (t ON11 ,t ON12 , ...) and the on-holding time of the second overvoltage protection circuit (t ON21 ,t ON22 , ...), since both the first overvoltage protection circuit and the second overvoltage protection circuit perform overvoltage protection operations, Figure 7 The embodiment shown in more effectively protects the wireless charging circuit from overvoltage.

[0077] according to Fig.10 In the embodiment shown in , the second switch OVP_SW2 is not closed at the second time t2, and the second switch OVP_SW2 is not opened at the third time t3. For example, at least a portion of the on-holding time of the second overvoltage protection circuit overlaps with each adjacent on-holding time of the first overvoltage protection circuit. For example, the first on-holding time t ON21 The first part and the first on-hold time t ON11 overlap, and the first on-hold time t of the second overvoltage protection circuit ON21 The second part and the second on-holding time t of the first overvoltage protection circuit ON12 Overlap. Fig. 9 Compared with the second switch OVP_SW2 shown in FIG. , the on-holding time t of the second switch OVP_SW2 ON21 ,t ON22 , ... increases, and therefore, the amount of current leakage through the second overvoltage protection circuit increases. Fig. 9 The embodiment shown in more effectively protects the wireless charging circuit from overvoltage.

[0078] according to Fig.11 and Fig.12 In the embodiment shown in , the second switch OVP_SW2 repeats the opening operation and the closing operation at regular intervals. For example, the second overvoltage protection circuit repeats the turning-on operation and the turning-off operation. Fig.11 and Fig.12 The detailed operation of the second switch OVP_SW2 shown in FIG. Figure 5 The operation of the second switch OVP_SW2 shown in FIG. 1 is substantially similar, and a repeated description thereof may be summarized or omitted.

[0079] Fig.11 The first on-holding time t of the first overvoltage protection circuit ON11 Longer than Figure 5 The first on-holding time t of the first overvoltage protection circuit ON11 The first on-hold time t ON11The first overvoltage protection circuit is changed according to the magnitude of the current source. For example, the longer the first on-hold time of the first overvoltage protection circuit is, the smaller the current emitted by the current source is.

[0080] according to Fig.12 In the embodiment shown in FIG. 1 , after the first switch OVP_SW1 is closed at the first time t1, it remains in the closed state. The first on-holding time (t ON11 ) is longer than the total on-hold time (t ON21 ,t ON22 For example, the total turn-off holding time of the first overvoltage protection circuit is shorter than the total turn-off holding time of the second overvoltage protection circuit (t OFF21 ,t OFF22 ,... and...). exist Fig.12 In the embodiment shown in , since the first switch OVP_SW1 is not repeatedly opened and closed, the wireless charging circuit is protected from power leaking through the first overvoltage protection circuit. Fig.12 The heat generated by the current source in the first overvoltage protection circuit shown in FIG. Figure 5 The heat of the embodiment.

[0081] Fig.13 A circuit diagram of an overvoltage protection circuit according to an embodiment is schematically shown. Fig.14 is a diagram showing a method according to an embodiment of the present invention. Fig.13 A graph of the operation of a switch in an overvoltage protection circuit as a function of time.

[0082] The wireless charging circuit includes a power receiving circuit, a rectifier circuit, a regulating circuit, a controller and an overvoltage protection circuit. Fig.13 The circuit diagram of the embodiment shown in FIG. 1 simply represents a circuit diagram of the overvoltage protection circuit 1600, and Fig.13 The configuration of the wireless charging circuit is omitted. Figure 4 Compared with the wireless charging circuit 610 , there is a difference in the configuration of the overvoltage protection circuit.

[0083] The overvoltage protection circuit 1600 is connected in parallel between the rectifier circuit and the regulating circuit, and the rectified voltage V RECT The output overvoltage protection rectified voltage V is input to RECT 'Overvoltage protection circuit 1600. The overvoltage protection circuit 1600 includes at least one current source and / or at least one resistor, and the current source and / or the resistor are connected in parallel. Fig.13In the embodiment shown in , the overvoltage protection circuit 1600 includes a first overvoltage protection circuit 1600A, a second overvoltage protection circuit 1600B, and a third overvoltage protection circuit 1600C. The first overvoltage protection circuit 1600A includes a first current source A1 and a first switch SW1, the second overvoltage protection circuit 1600B includes a second current source A2 and a second switch SW2, and the third overvoltage protection circuit 1600C includes a resistor R and a third switch SW3. For example, the first current I1 leaked by the first overvoltage protection circuit 1600A may be the same as the second current I2 leaked by the second overvoltage protection circuit 1600B or different from the second current I2 leaked by the second overvoltage protection circuit 1600B. The configuration of the overvoltage protection circuit 1600 is not necessarily limited thereto.

[0084] The turning on of the overvoltage protection circuits 1600A, 1600B, and 1600C changes according to the operating conditions satisfied by the overvoltage protection circuit 1600. For example, in an embodiment, the controller turns on only one of the first to third overvoltage protection circuits 1600A, 1600B, and 1600C alternately at a certain time, but embodiments of the inventive concept are not necessarily limited thereto.

[0085] according to Fig.14 In the embodiment shown in , when the first operating condition of the overvoltage protection circuit 1600 is met, the first switch SW1 is closed. When the second operating condition of the overvoltage protection circuit 1600 is met, the first switch SW1 is opened and the second switch SW2 is closed. When the third operating condition of the overvoltage protection circuit 1600 is met, the open state of the first switch SW1 is maintained, and the second switch SW2 is opened, and the third switch SW3 is closed. Then, one of the first switch SW1 to the third switch SW3 is alternately closed.

[0086] For example, when the overvoltage protection circuit 1600 satisfies the first operating condition, the first overvoltage protection circuit 1600A is turned on. When the overvoltage protection circuit 1600 satisfies the second operating condition, the first overvoltage protection circuit 1600A is turned off and the second overvoltage protection circuit 1600B is turned on. When the overvoltage protection circuit 1600 satisfies the third operating condition, the second overvoltage protection circuit 1600B is turned off and the third overvoltage protection circuit 1600C is turned on. For example, only one of the first to third overvoltage protection circuits 1600A, 1600B, and 1600C is alternately turned on.

[0087] The first operating condition refers to when the rectified voltage V RECT is greater than or equal to the first threshold voltage or the temperature of the wireless charging circuit is greater than or equal to the first threshold temperature. The second operating condition refers to when the rectified voltage V RECTis greater than or equal to the second threshold voltage or the temperature of the wireless charging circuit is equal to or greater than the second threshold temperature. The third operating condition refers to when the rectified voltage V RECT When the voltage is greater than or equal to the third threshold voltage or the temperature of the wireless charging circuit is equal to or greater than the third threshold temperature, the third threshold voltage is greater than the first threshold voltage and the second threshold voltage, and the third threshold temperature is higher than the first threshold temperature and the second threshold temperature.

[0088] and Figure 4 Compared with the overvoltage protection circuit 613 shown in FIG. Fig.13 The overvoltage protection circuit 1600 shown in FIG. 1 also includes an additional overvoltage protection circuit having a current source. Therefore, Fig.13 The power leakage efficiency is higher than Figure 4 In addition, Fig.14 The off holding time of each of the overvoltage protection circuits 1600A, 1600B, and 1600C shown in FIG. 1 is longer than Figure 4 For example, by ensuring sufficient time to reduce the off holding time of each of the overvoltage protection circuits 613A and 613B. Fig.13 The temperature of the resistor R and / or the internal temperature of the wireless charging circuit can effectively protect the wireless charging circuit and / or the resistor R from high temperature.

[0089] Fig.13 The operation of the switches SW1-SW3 in the overvoltage protection circuit 1600 shown in FIG. 1 is not necessarily limited to Fig.14 of those, and can be applied Figures 6 to 12 At least one of the switching operations shown in .

[0090] Fig.15 is a graph of temperature variation of a wireless charging circuit and a resistor as a function of time when an overvoltage protection circuit operates according to an embodiment.

[0091] The wireless charging circuit includes a power receiving circuit, a rectifier circuit, a regulating circuit, a controller, and an overvoltage protection circuit. The overvoltage protection circuit includes a first overvoltage protection circuit having a current source and a second overvoltage protection circuit having a resistor. Even when an overvoltage occurs in the power receiving circuit, the battery can be charged at a constant voltage by leaking power in the overvoltage protection circuit.

[0092] When the overvoltage protection circuit leaks power, the temperature of the wireless charging circuit or the temperature of the resistor increases. When the temperature of the wireless charging circuit becomes high, damage to the wireless charging circuit may occur. When the temperature of the resistor increases, the efficiency of power leakage through the resistor decreases. In an embodiment of the present inventive concept, by alternately turning on only one of the first overvoltage protection circuit and the second overvoltage protection circuit, the temperature (T IC ) and the temperature of the resistor (T R ) can be maintained within a predetermined range. In an embodiment, the temperature T of the wireless charging circuit IC is maintained within a first predetermined range based on the first temperature T1, and the temperature T R The temperature T2 is maintained within a second predetermined range based on the second temperature T2. For example, the second temperature T2 is higher than the first temperature T1, but is not necessarily limited thereto.

[0093] exist Fig.15 In the embodiment shown in FIG. 1 , when the first overvoltage protection circuit is turned on, the temperature T of the wireless charging circuit IC When the first overvoltage protection circuit is turned off, the temperature T IC When the second overvoltage protection circuit is turned on, the temperature of the resistor T R increases, and when the second overvoltage protection circuit is turned off, the temperature T of the resistor R Since the first overvoltage protection circuit and the second overvoltage protection circuit are alternately turned on and off, when the temperature T IC At the highest point, the resistor temperature T R The lowest temperature of the wireless charging circuit is T IC When the resistor temperature is at its lowest, T R Highest.

[0094] Fig.16 is a block diagram of an electronic device according to an embodiment.

[0095] according to Fig.16 In the embodiment shown in , the electronic device 2000 includes a processor 2120, a memory 2130, an input module 2150, a sensor module 2176, an interface 2177, a connection terminal 2178, a wireless power receiving module 2188, a battery 2189, etc. In addition, the electronic device 2000 includes a display module 2160, a sound output module 2155, a communication module 2190 including a wireless communication module 2192 and a wired communication module 2194, an audio module 2170, a haptic module 2179, a camera module 2180, an antenna module 2197, and a subscriber identification module 2196.

[0096] The processor 2120 executes software that controls at least one of the components of the electronic device 2000 connected to the processor 2120, and also performs various data processing operations or calculations. According to an embodiment, the processor 2120 stores commands or data received from other components in the volatile memory 2132, processes the commands or data stored in the volatile memory 2132, and stores the resulting data in the non-volatile memory 2134. According to an embodiment, the processor 2120 includes a main processor 2121 (such as a central processing unit, etc.) and an auxiliary processor 2123 (such as a graphics processing unit and / or a communication processor, etc.). The auxiliary processor 2123 uses less power than the main processor 2121.

[0097] The memory 2130 stores data used by the components of the electronic device 2000. The memory 2130 includes a volatile memory 2132 and / or a nonvolatile memory 2134. The nonvolatile memory 2134 includes a built-in memory 2136 and an external memory 2138. The input module 2150 receives a command or data from outside the electronic device 2000 to be used by the electronic device 2000. For example, the input module 2150 includes one or more of a microphone, a mouse, a keyboard, a key, and a digital pen.

[0098] The sensor module 2176 detects an operating state such as power or temperature of the electronic device 2000, or an external environmental state, and generates an electrical signal or data value corresponding to the sensed state. The interface 2177 supports one or more specified communication protocols that can be used to connect the electronic device 2000 directly or wirelessly to an external electronic device. The connection terminal 2178 includes a connector through which the electronic device 2000 can be physically connected to an external electronic device.

[0099] The wireless power receiving module 2188 manages the power wirelessly supplied to the electronic device 2000. According to an embodiment, the wireless power receiving module is implemented as a part of a power management integrated circuit (PMIC). According to an embodiment, the wireless power receiving module 2188 includes a wireless power receiver, a controller, and a communication unit, and the detailed embodiment is the same as that of the reference Figure 2 and Figure 3 Similar to those described.

[0100] The battery 2189 supplies power to at least one component of the electronic device 2000, and according to an embodiment, may be wirelessly charged through the wireless power receiving module 2188. The battery 2189 includes a rechargeable secondary cell or a fuel cell.

[0101] In an embodiment, the wireless power receiving module 2188 includes an overvoltage protection circuit. The overvoltage protection circuit includes at least one current source and / or at least one resistor connected in parallel. At least one current source and / or at least one resistor are alternately connected to the wireless charging circuit at regular intervals. Therefore, by maintaining the temperature of the wireless power receiving module 2188 within a predetermined range, damage to the wireless power receiving module 2188 that may occur due to high temperature can be prevented.

[0102] Fig.17 is a flow chart of an operation process of an overvoltage protection circuit according to an embodiment.

[0103] In an embodiment, a wireless charging system includes a wireless power transmitter and a wireless power receiver. The wireless power transmitter includes a power transmitter (Tx), a controller, and a communication unit. The wireless power transmitter sends power to the wireless power receiver through the power transmitter Tx in an alternating current form. The wireless power receiver includes a power receiver (Rx), a controller, a communication unit, and a battery. The wireless power receiver receives AC power from the wireless power transmitter through the power receiver Rx and converts the AC power into DC power that can charge the battery.

[0104] according to Fig.17 In the embodiment shown in FIG. 1 , the power receiver Rx requests power from the power transmitter Tx (S101), and the power receiver Rx also transmits information about the power required for charging the battery through a communication unit. The power transmitter Tx generates AC power using the received information and transmits the generated AC power to the power receiver Rx (S102). The power is transmitted in the form of electromagnetic waves.

[0105] The power receiver Rx rectifies the received AC power and discharges the rectified voltage to the overvoltage protection circuit. The controller in the wireless power receiver detects the rectified voltage (S103) and compares the detected voltage with the first threshold voltage (S104). If the rectified voltage is not equal to or greater than the first threshold voltage, the rectified voltage is detected again (S103). When the rectified voltage is equal to or greater than the first threshold voltage, the first overvoltage protection circuit is turned on (S105).

[0106] The controller detects the rectified voltage again and compares the detected voltage with the second threshold voltage (S106). If the rectified voltage is not equal to or greater than the second threshold voltage, the rectified voltage is detected again (S103). When the rectified voltage is equal to or greater than the second threshold voltage, the first overvoltage protection circuit is turned off and the second overvoltage protection circuit is turned on (S107). Afterwards, the first overvoltage protection circuit and the second overvoltage protection circuit repeat the turning-on operation and the turning-off operation at regular intervals (S108).

[0107] The controller detects the rectified voltage again and compares the detected voltage with the second threshold voltage (S109). If the rectified voltage is not equal to or less than the second threshold voltage, the rectified voltage is detected again (S103). When the rectified voltage is less than or equal to the second threshold voltage, the second overvoltage protection circuit is turned off (S110).

[0108] Afterwards, the rectified voltage is compared with the first threshold voltage (S111). If the rectified voltage is not equal to or less than the first threshold voltage, the rectified voltage can be detected again (S103). When the rectified voltage is less than or equal to the first threshold voltage, the first overvoltage protection circuit is turned off (S112).

[0109] By operating the first overvoltage protection circuit and the second overvoltage protection circuit based on the rectified voltage, the wireless charging circuit is more accurately protected from overvoltage. In addition, since the first overvoltage protection circuit and the second overvoltage protection circuit are alternately turned on and off, the temperature of the wireless charging circuit and the resistor is maintained within a predetermined range, and overvoltage protection is also effectively performed.

[0110] Fig.18 is a flow chart of an operation process of an overvoltage protection circuit according to an embodiment.

[0111] Fig.17 The operating standard of the overvoltage protection circuit is the rectified voltage condition, while Fig.18 and Fig.17 The difference is that the operating criterion of the overvoltage protection circuit is the temperature of the wireless charging circuit. Fig.18 Detailed embodiments and Fig.17 The detailed embodiments described in are basically similar.

[0112] according to Fig.18 In the embodiment shown in , the power receiver Rx requests power from the power transmitter Tx ( S201 ), and the power transmitter (Tx) generates AC power and transmits the power to the power receiver (Rx) ( S202 ).

[0113] The power receiver Rx rectifies the received AC power and discharges the rectified voltage to the overvoltage protection circuit. The controller in the wireless power receiver detects the temperature of the wireless charging circuit (S203) and compares the detected temperature with the first threshold temperature (S204). If the temperature of the wireless charging circuit is not equal to or higher than the first threshold temperature, the temperature of the wireless charging circuit is detected again (S203). When the temperature of the wireless charging circuit is equal to or higher than the first threshold temperature, the first overvoltage protection circuit is turned on (S205).

[0114] The controller detects the temperature of the wireless charging circuit again and compares the detected temperature with the second threshold temperature (S206). If the temperature of the wireless charging circuit is not equal to or higher than the second threshold temperature, the temperature of the wireless charging circuit is detected again (S203). When the temperature of the wireless charging circuit is equal to or higher than the second threshold temperature, the first overvoltage protection circuit is turned off and the second overvoltage protection circuit is turned on (S207). Thereafter, the first overvoltage protection circuit and the second overvoltage protection circuit repeat the turning-on operation and the turning-off operation at regular intervals (S208).

[0115] The controller detects the temperature of the wireless charging circuit and compares the detected temperature with the second threshold temperature again (S209). When the temperature of the wireless charging circuit is not equal to or less than the second threshold temperature, the temperature of the wireless charging circuit is detected again (S203). When the temperature of the wireless charging circuit is less than or equal to the second threshold temperature, the second overvoltage protection circuit is turned off (S210).

[0116] The temperature of the wireless charging circuit is compared with a first threshold temperature (S211). If the temperature of the wireless charging circuit is not equal to or less than the first threshold temperature, the temperature of the wireless charging circuit is detected again (S203). When the temperature of the wireless charging circuit is less than or equal to the first threshold temperature, the first overvoltage protection circuit is turned off (S212).

[0117] By operating the first overvoltage protection circuit and the second overvoltage protection circuit based on the temperature of the wireless charging circuit, the wireless charging circuit can be effectively protected from high temperature. In addition, since the first overvoltage protection circuit and the second overvoltage protection circuit are alternately turned on and off, the heat generated by the wireless charging circuit and the resistor is maintained within a predetermined range, and the overvoltage protection also operates effectively.

[0118] As explained above, according to the embodiment, when an overvoltage occurs in the wireless charging circuit, power loss is effectively generated by turning on the overvoltage protection circuit. The wireless charging circuit includes a first overvoltage protection circuit and a second overvoltage protection circuit, and by repeating the turning-on operation and the turning-off operation for at least one of the first overvoltage protection circuit and the second overvoltage protection circuit, circuit damage due to heat can be prevented.

[0119] While embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of embodiments of the inventive concept as defined by the appended claims.

Claims

1. A wireless charging circuit, comprising: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies the AC voltage received from the power receiving circuit and outputs the rectified voltage; a regulating circuit which outputs a charging voltage for charging a battery using the rectified voltage; an overvoltage protection circuit connected in parallel between the rectifier circuit and the regulating circuit; as well as a controller that detects the rectified voltage and controls the overvoltage protection circuit, The overvoltage protection circuit includes a first overvoltage protection circuit and a second overvoltage protection circuit, wherein the second overvoltage protection circuit is turned off when the first overvoltage protection circuit is turned on, and the second overvoltage protection circuit is turned on when the first overvoltage protection circuit is turned off.

2. The wireless charging circuit according to claim 1, wherein: The power supplied to the regulation circuit is less than the power received from the rectifier circuit.

3. The wireless charging circuit according to claim 1, wherein: The first overvoltage protection circuit includes a current source, and the second overvoltage protection circuit includes a resistor.

4. The wireless charging circuit according to claim 3, wherein: The power supplied to the regulation circuit when the second overvoltage protection circuit is turned on is less than the power supplied to the regulation circuit when the first overvoltage protection circuit is turned on.

5. The wireless charging circuit according to claim 1, wherein: The controller turns on the first overvoltage protection circuit when the rectified voltage is equal to or greater than a first threshold voltage, and turns on the second overvoltage protection circuit when the rectified voltage is greater than or equal to a second threshold voltage.

6. The wireless charging circuit according to claim 5, wherein: The second threshold voltage is greater than the first threshold voltage.

7. The wireless charging circuit according to claim 5, wherein: The on-holding time of the first overvoltage protection circuit is equal to the on-holding time of the second overvoltage protection circuit.

8. The wireless charging circuit according to claim 1, wherein: The controller detects a temperature of the wireless charging circuit, and The first overvoltage protection circuit is turned on when the temperature of the wireless charging circuit is greater than or equal to a first threshold temperature, and the second overvoltage protection circuit is turned on when the temperature of the wireless charging circuit is greater than or equal to a second threshold temperature.

9. The wireless charging circuit according to claim 8, wherein: The second threshold temperature is greater than the first threshold temperature.

10. The wireless charging circuit according to claim 9, wherein: The on-holding time of the first overvoltage protection circuit is the same as the on-holding time of the second overvoltage protection circuit.

11. A wireless charging circuit, comprising: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies the AC voltage received from the power receiving circuit and outputs the rectified voltage; a regulating circuit which outputs a charging voltage for charging a battery using the rectified voltage; an overvoltage protection circuit connected in parallel between the rectifier circuit and the regulating circuit; as well as a controller that detects the rectified voltage and controls the overvoltage protection circuit, The overvoltage protection circuit includes a first overvoltage protection circuit and a second overvoltage protection circuit, the first overvoltage protection circuit is turned on before the second overvoltage protection circuit, and at least one of the first overvoltage protection circuit and the second overvoltage protection circuit is repeatedly turned on and off.

12. The wireless charging circuit according to claim 11, wherein: The first overvoltage protection circuit is repeatedly turned on and off.

13. The wireless charging circuit according to claim 12, wherein: A first turn-on time of the second overvoltage protection circuit is consistent with a first turn-off time of the first overvoltage protection circuit.

14. The wireless charging circuit according to claim 13, wherein: A total off-holding time of the second overvoltage protection circuit is shorter than a total off-holding time of the first overvoltage protection circuit.

15. The wireless charging circuit according to claim 13, wherein: The total turn-off holding time of the second overvoltage protection circuit is longer than the total turn-off holding time of the first overvoltage protection circuit, and At least a portion of a turn-off holding time of the second overvoltage protection circuit overlaps with a turn-off holding time of the first overvoltage protection circuit.

16. The wireless charging circuit according to claim 12, wherein: At least a portion of an on-holding time of the second overvoltage protection circuit overlaps with an on-holding time of the first overvoltage protection circuit.

17. The wireless charging circuit according to claim 12, wherein: At least a portion of the turn-off holding time of the second overvoltage protection circuit overlaps with each adjacent turn-off holding time of the first overvoltage protection circuit.

18. The wireless charging circuit according to claim 11, wherein: The second overvoltage protection circuit is repeatedly turned on and off.

19. A wireless charging circuit, comprising: a power receiving circuit that wirelessly receives power and includes an inductor and a capacitor; a rectifier circuit that rectifies the AC voltage received from the power receiving circuit and outputs the rectified voltage; a regulating circuit which outputs a charging voltage for charging a battery using the rectified voltage; an overvoltage protection circuit, the overvoltage protection circuit comprising at least one first overvoltage protection circuit and at least one second overvoltage protection circuit, the at least one first overvoltage protection circuit being connected in parallel between the rectifier circuit and the regulating circuit and comprising a current source, the at least one second overvoltage protection circuit being connected in parallel between the rectifier circuit and the regulating circuit and comprising an external resistor; as well as a controller that detects the rectified voltage and controls the overvoltage protection circuit, wherein the controller turns on the first overvoltage protection circuit when the overvoltage protection circuit meets a first operating condition, When the overvoltage protection circuit meets a second operating condition, the first overvoltage protection circuit is turned off and the second overvoltage protection circuit is turned on, and One of the first overvoltage protection circuit and the second overvoltage protection circuit is turned on.

20. The wireless charging circuit according to claim 19, wherein: The controller detects the temperature of the wireless charging circuit. The first operating condition is when the rectified voltage is greater than or equal to a first threshold voltage or when the temperature of the wireless charging circuit is greater than or equal to a first threshold temperature, The second operating condition is when the rectified voltage is greater than or equal to a second threshold voltage or when the temperature of the wireless charging circuit is greater than or equal to a second threshold temperature, and The second threshold voltage is greater than the first threshold voltage, and the second threshold temperature is higher than the first threshold temperature.

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