Wireless charging circuit and system, electronic device and control method

Abstract

The application provides a wireless charging circuit and system, an electronic device and a control method, relates to the technical field of wireless charging, and aims to improve the problem of small charging power of an electronic device with a wireless reverse charging function. In the wireless charging circuit, a first voltage conversion circuit converts a power supply voltage into a first battery voltage of a first battery, and charges the first battery. The first voltage conversion circuit also outputs the first battery voltage provided by the first battery. A second voltage conversion circuit boosts the first battery voltage. The second voltage conversion circuit comprises a first voltage boosting circuit and at least one stage of a switched capacitor direct current converter connected in series. A first alternating current-direct current conversion circuit converts a direct current voltage output by the second voltage conversion circuit into an alternating current voltage.

Description

Technical Field

[0001] This application relates to the field of wireless charging technology, and in particular to a wireless charging circuit and system, electronic device and control method. Background Technology

[0002] Wireless charging technology (WCT) uses conductive media such as electric fields, magnetic fields, microwaves, or lasers to achieve wireless transmission of electrical energy. Due to its advantages such as no wire restrictions and no plugging and unplugging, it is being used more and more widely in electronic devices.

[0003] To further enhance the user experience, some electronic devices, such as mobile phones, employ wireless charging technology. This technology uses a wireless coil to emit electromagnetic waves, which can then charge other wirelessly charging-enabled devices in reverse. Currently, the charging power provided by these devices is relatively low, typically between 5W and 10W. This low charging power results in slow charging speeds, significant charging losses, and high emission levels during reverse wireless charging, thus degrading the user experience. Summary of the Invention

[0004] This application provides a wireless charging circuit and system, an electronic device and a control method to improve the problem of low charging power in electronic devices with wireless reverse charging function.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] One aspect of this application provides a wireless charging circuit. This wireless charging circuit can be integrated into a chip. The wireless charging circuit may include a first voltage conversion circuit, a second voltage conversion circuit, and a first AC-DC conversion circuit. The first voltage conversion circuit is electrically connected to a first battery. The first voltage conversion circuit is used to convert the power supply voltage into a first battery voltage for charging the first battery. The first voltage conversion circuit is also used to output the first battery voltage provided by the first battery. The second voltage conversion circuit is electrically connected to the first voltage conversion circuit and is used to boost the first battery voltage. The second voltage conversion circuit includes a first boost circuit connected in series and at least one stage of switched-capacitor DC-DC converter. The first AC-DC conversion circuit is electrically connected to the second voltage conversion circuit and is used to convert the DC voltage output by the second voltage conversion circuit into an AC voltage. In summary, the second voltage conversion circuit of the wireless charging circuit provided in this application embodiment includes a first boost circuit. When an electronic device equipped with this wireless charging circuit performs wireless reverse charging on an electronic device to be charged, the difference between the output voltage and input voltage of the first boost circuit can be reduced, allowing the first boost circuit to operate at or near its peak voltage conversion efficiency. This reduces the heating of the inductor in the first boost circuit and improves its voltage conversion efficiency. Furthermore, to provide greater charging power during the reverse charging process, the second voltage conversion circuit may include at least one stage of a switched-capacitor DC-DC converter connected in series with the first boost circuit. This switched-capacitor DC-DC converter mainly consists of multiple switching transistors and capacitors. It is an inductive DC-DC voltage converter without internal inductors. Therefore, by controlling the on / off state of the switching transistors in the switched-capacitor DC-DC converter, the capacitors can be charged and discharged, achieving a boost in the input voltage and resulting in higher voltage conversion efficiency. In this way, when the first voltage circuit and at least one switched-capacitor DC-DC converter in series both boost the input voltage, the second voltage conversion circuit can output a larger voltage while maintaining high voltage conversion efficiency. This allows the electronic device to output a larger charging power when wirelessly reverse-charging the electronic device being charged, thereby increasing the charging speed. Furthermore, the switched-capacitor DC-DC transformer is small in size, which helps to increase the power density of the electronic device. It also generates less electromagnetic interference to the radio frequency circuitry.

[0007] Optionally, the wireless charging circuit further includes a second boost circuit and a second AC-DC converter circuit. The second boost circuit is electrically connected to the first voltage conversion circuit and is used to boost the voltage of the first battery before outputting it. The boost factor of the second boost circuit is less than or equal to the boost factor of the first boost circuit. The second AC-DC converter circuit is electrically connected to the second boost circuit and is used to convert the DC voltage output by the second boost circuit into an AC voltage. Thus, when an electronic device to be charged is located at the position of the second coil in an electronic device with this wireless charging circuit, the electronic device can reverse charge the electronic device to be charged through the charging path formed by the second boost circuit, the second AC-DC converter circuit, and the second coil.

[0008] Optionally, the first boost circuit has a feedback terminal. The second voltage conversion circuit further includes a pull-up resistor, a pull-down resistor, and an adjustable resistor. The first end of the pull-up resistor is electrically connected to the output terminal of the first boost circuit, and the second end of the pull-up resistor is electrically connected to the feedback terminal of the first boost circuit. The first end of the pull-down resistor is electrically connected to the feedback terminal of the first boost circuit, and the second end of the pull-down resistor is grounded. The first end of the adjustable resistor is electrically connected to the feedback terminal of the first boost circuit, and the second end of the adjustable resistor is used to be left floating, grounded, or to receive a pulse width modulation signal. Thus, when the electronic device with the above-described wireless charging circuit performs low-power charging on the electronic device to be charged at the first coil location, the processor of the electronic device can control the second end of the adjustable resistor to be left floating. When the electronic device performs high-power charging on the electronic device to be charged at the first coil location, the processor can control the second end of the adjustable resistor to be grounded, or provide a pulse width modulation signal to the second end of the adjustable resistor according to the efficiency peak value of the first boost circuit, so that the voltage output by the first boost circuit is adjusted as needed.

[0009] Optionally, the first boost circuit and at least one switched-capacitor DC-DC converter are sequentially electrically connected between the first voltage conversion circuit and the first AC-DC conversion circuit. In this case, since the switched-capacitor DC-DC converter is located at the output terminal of the first boost circuit, the voltage input to the switched-capacitor DC-DC converter from the first boost circuit is greater than the voltage at the input terminal of the first boost circuit. Therefore, the withstand voltage requirement of the switching transistor in the switched-capacitor DC-DC converter is higher than that of the switching transistor in the first boost circuit, thereby reducing the withstand voltage requirement of the switching transistor in the first boost circuit.

[0010] Optionally, the wireless charging circuit also includes a first switching circuit. The control terminal of the first switching circuit receives a first switching control signal. The first terminal of the first switching circuit is electrically connected to the input terminal of the first voltage conversion circuit, and the second terminal of the first switching circuit is electrically connected between the first boost circuit and at least one stage of a switched-capacitor DC-DC converter. The first switching circuit is used to turn on or off according to the first switching control signal. The first AC-DC conversion circuit is also used to convert the AC voltage induced by the first coil of the electronic device with the above-mentioned wireless charging circuit into a DC voltage. When a wireless charging circuit is provided at the first coil location, the processor can control the first switching circuit to be in a conducting state and control the at least one stage of a switched-capacitor DC-DC converter electrically connected between the second terminal of the first switching circuit and the first AC-DC conversion circuit to operate in bypass mode, i.e., equivalent to a wire. At this time, the DC voltage output by the first AC-DC conversion circuit can be transmitted to the first voltage conversion circuit through the switched-capacitor DC-DC converter operating in bypass mode and the first switching circuit to charge the first battery, realizing forward charging of the electronic device. Furthermore, at least one switched-capacitor DC-DC converter, which is electrically connected between the second terminal of the first switching circuit and the first AC-DC conversion circuit, operates in bypass mode. This switched-capacitor DC-DC converter itself has a certain resistance, so when the DC voltage output by the first AC-DC conversion circuit passes through the switched-capacitor DC-DC converter operating in bypass mode, the voltage value is slightly reduced, thereby reducing the withstand voltage of the switching transistor in the first switching circuit used to receive the DC voltage.

[0011] Optionally, the wireless charging circuit also includes a first switching circuit. The control terminal of the first switching circuit receives a first switching control signal. A first terminal of the first switching circuit is electrically connected to the input terminal of a first voltage conversion circuit, and a second terminal of the first switching circuit is electrically connected to a first AC-DC conversion circuit. The first switching circuit is used to turn on or off according to the first switching control signal. The first coil also receives an alternating magnetic field and induces an AC voltage. The first AC-DC conversion circuit further converts the AC voltage on the first coil into a DC voltage. The DC voltage output by the first AC-DC conversion circuit can be directly transmitted through the first switching circuit to the first voltage conversion circuit to charge the first battery, thus achieving forward charging of the electronic device.

[0012] Optionally, the first switching circuit includes a first switching transistor, a second switching transistor, a first resistor, a second resistor, and a third switching transistor. The first terminal of the first switching transistor serves as the first terminal of the first switching circuit. The first terminal of the second switching transistor is electrically connected to the second terminal of the first switching transistor, and the second terminal of the second switching transistor serves as the second terminal of the first switching circuit. The first terminal of the first resistor is electrically connected to both the second terminal of the first switching transistor and the first terminal of the second switching transistor, and the second terminal of the first resistor is electrically connected to the gates of the first and second switching transistors. The first terminal of the second resistor is electrically connected to the second terminal of the second resistor. The second terminal of the third switching transistor is grounded, and the gate of the third switching transistor serves as the control terminal of the first switching circuit and is electrically connected to the processor to receive the first switching control signal issued by the processor. When the processor controls the third switching transistor to conduct via the first switching control signal, both the first and second switching transistors are conducted, and the entire first switching circuit is in a conducting state. When the processor controls the third switching transistor to cut off via the first switching control signal, both the first and second switching transistors are cut off, and the entire first switching circuit is in a disconnected state. In addition, the first resistor and the second resistor, through the voltage division effect, ensure that the voltage across the gate and source (or drain) of the first switch and the second switch is within a reasonable range, so that the voltage across the switch can avoid damage to the switch when it is turned on.

[0013] Optionally, the wireless charging circuit also includes a second switching circuit. The control terminal of the second switching circuit receives a second switching control signal. The first terminal of the second switching circuit is electrically connected to the first boost circuit, and the second terminal is electrically connected to at least one stage of a switched-capacitor DC-DC converter. The second switching circuit is used to turn on or off according to the second switching control signal. In this case, when the wireless charging power supply is forward charging the electronic device, the processor can output a second switching control signal to the control terminal of the second switching circuit to control the second switching circuit to be in the off state. This avoids the DC voltage output by the switched-capacitor DC-DC converter being too high during the forward charging process, which could damage the switching transistor in the first boost circuit.

[0014] Optionally, the second switching circuit includes a fourth switching transistor, a third resistor, a fifth switching transistor, a fourth resistor, a fifth resistor, and a sixth switching transistor. The first terminal of the fourth switching transistor serves as the first terminal of the second switching circuit, and the second terminal of the fourth switching transistor serves as the second terminal of the second switching circuit. The first terminal of the third resistor is electrically connected to the gate of the fourth switching transistor, and the second terminal is electrically connected to the second terminal of the fourth switching transistor. The first terminal of the fifth switching transistor is electrically connected to the first terminal of the fourth switching transistor, and the second terminal of the fifth switching transistor is electrically connected to the second terminal of the fourth switching transistor. The first terminal of the fourth resistor is electrically connected to the gates of both the fourth and fifth switching transistors, and the second terminal is electrically connected to the second terminal of the fifth switching transistor. The first terminal of the fifth resistor is electrically connected to the gate of the fifth switching transistor. The first terminal of the sixth switching transistor is electrically connected to the second terminal of the fifth resistor, the second terminal of the sixth switching transistor is grounded, and the gate of the sixth switching transistor serves as the control terminal of the second switching circuit, electrically connected to the processor, for receiving the second switching control signal output by the processor. In this case, when the processor controls the sixth switching transistor to conduct via the second switching control signal, both the fourth and fifth switching transistors are turned on, and the entire second switching circuit is in a conducting state. The fourth and fifth switching transistors are connected in parallel. When the first boost circuit outputs an electrical signal to the switched capacitor DC-DC converter through the second switching circuit, it can effectively reduce the on-resistance of the second switching circuit, thereby improving signal transmission efficiency. Furthermore, the series-connected third and fifth resistors, through voltage division, ensure that the voltage across the gate and source (or drain) of the fourth switching transistor is within a reasonable range, thus preventing damage to the switching transistor while it is conducting. Similarly, the series-connected fourth and fifth resistors, through voltage division, ensure that the voltage across the gate and source (or drain) of the fifth switching transistor is within a reasonable range. Moreover, when the processor controls the sixth switching transistor to turn off via the second switch control signal, both the fourth and fifth switching transistors are in the off state, and the entire second switching circuit is in the open state.

[0015] Optionally, the wireless charging circuit also includes a third switch circuit. The control terminal of the third switch circuit receives a third switch control signal. The first terminal of the third switch circuit is electrically connected to the USB interface, and the second terminal is electrically connected to the output terminal of the second boost circuit. The third switch circuit is used to turn on or off according to the third switch control signal. When the third switch circuit is on, the electronic device can supply power to an external device electrically connected to it via the USB interface for data transmission.

[0016] Optionally, the wireless charging circuit also includes a fourth switch circuit. The control terminal of the fourth switch circuit receives a fourth switch control signal. The first terminal of the fourth switch circuit is electrically connected to the output terminal of the second boost circuit, and the second terminal of the fourth switch circuit is electrically connected to the second AC-DC conversion circuit. The fourth switch circuit is used to turn on or off according to the fourth switch control signal. When the fourth switch circuit is on, the electronic device with this wireless charging circuit can wirelessly reverse charge the electronic device to be charged located at the second coil position.

[0017] Optionally, the wireless charging circuit also includes a fifth switch circuit. The control terminal of the fifth switch circuit receives a fifth switch control signal. The first terminal of the fifth switch circuit is electrically connected to the USB interface, and the second terminal is electrically connected to the input terminal of the first voltage conversion circuit. The fifth switch circuit is used to turn on or off according to the fifth switch control signal. When the USB interface is electrically connected to a charging power source, the fifth switch circuit can be controlled to turn on to perform wired forward charging of the electronic device. When a wireless charging circuit is provided at the first coil position of the electronic device, the fifth switch circuit can be controlled to turn off, thereby avoiding conflict between wireless and wired forward charging methods.

[0018] Optionally, any one of the at least one switched-capacitor DC-DC converters includes a seventh switch, an eighth switch, a first capacitor, a ninth switch, and a tenth switch. The first terminal of the seventh switch serves as the input terminal of the switched-capacitor DC-DC converter. The first terminal of the eighth switch is electrically connected to the second terminal of the seventh switch, and the second terminal of the eighth switch serves as the output terminal of the switched-capacitor DC-DC converter. The first terminal of the first capacitor is electrically connected to the second terminal of the seventh switch. The first terminal of the ninth switch is electrically connected to the second terminal of the first capacitor, and the second terminal of the ninth switch is grounded. The first terminal of the tenth switch is electrically connected to the first terminal of the seventh switch, and the second terminal of the tenth switch is electrically connected to the second terminal of the first capacitor. The switched-capacitor DC-DC converter uses these four switches and one capacitor to boost the input voltage.

[0019] Optionally, any one of the at least one switched-capacitor DC-DC converters includes a seventh switch, an eighth switch, a first capacitor, a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a second capacitor, a thirteenth switch, and a fourteenth switch. The first terminal of the seventh switch serves as the input terminal of the switched-capacitor DC-DC converter. The first terminal of the eighth switch is electrically connected to the second terminal of the seventh switch, and the second terminal of the eighth switch serves as the output terminal of the switched-capacitor DC-DC converter. The first terminal of the first capacitor is electrically connected to the second terminal of the seventh switch. The first terminal of the ninth switch is electrically connected to the second terminal of the first capacitor, and the second terminal of the ninth switch is electrically connected to the second terminal of the eighth switch. The first terminal of the tenth switch is electrically connected to the first terminal of the seventh switch, and the second terminal of the tenth switch is electrically connected to the second terminal of the first capacitor. The second terminal of the eleventh switch is electrically connected to the first terminal of the seventh switch. The first terminal of the twelfth switch is grounded, and the second terminal of the twelfth switch is electrically connected to the first terminal of the eleventh switch. The first terminal of the second capacitor is electrically connected to the first terminal of the eleventh switch. The first terminal of the thirteenth switch is grounded, and its second terminal is electrically connected to the second terminal of the second capacitor. The first terminal of the fourteenth switch is electrically connected to the second terminal of the second capacitor, and its second terminal is electrically connected to the second terminal of the eleventh switch. In this switched-capacitor DC-DC converter, the above eight switches and two capacitors achieve a positive input voltage. The use of a relatively large number of switches in this converter is beneficial for increasing the output current.

[0020] Optionally, at least one stage of switched-capacitor DC-DC converter includes a first-stage switched-capacitor DC-DC converter and a second-stage switched-capacitor DC-DC converter, with the output terminal of the first-stage switched-capacitor DC-DC converter electrically connected to the input terminal of the second-stage switched-capacitor DC-DC converter. The second voltage conversion circuit also includes a third boost circuit, which is connected in parallel with the first boost circuit. The boost factor of the third boost circuit is the same as that of the first boost circuit. In this way, the output voltage of the second voltage conversion circuit can be further increased by the first-stage switched-capacitor DC-DC converter and the second-stage switched-capacitor DC-DC converter, thereby improving the output power of the electronic device during reverse charging. In addition, the wireless charging circuit also includes a first diode and a second diode. The anode of the first diode is electrically connected to the output terminal of the first boost circuit, and the cathode is electrically connected to the first AC-DC conversion circuit. The anode of the second diode is electrically connected to the output terminal of the third boost circuit, and the cathode is electrically connected to the first AC-DC conversion circuit. The aforementioned first diode and second diode can prevent signal crosstalk between the parallel-connected first-stage switched-capacitor DC-DC converter and the second-stage switched-capacitor DC-DC converter.

[0021] Optionally, the wireless charging circuit also includes a third diode. The anode of the third diode is electrically connected to the input terminal of the switched-capacitor DC-DC converter, and the cathode of the third diode is electrically connected to the output terminal of the switched-capacitor DC-DC converter. In this way, when the first boost circuit provides voltage to the input terminal of the switched-capacitor DC-DC converter through the first switching circuit, the output terminal of the switched-capacitor DC-DC converter also has voltage due to the freewheeling effect of the third diode. Furthermore, when the voltage at the output terminal of the third diode is greater than the voltage at the input terminal, pre-starting of the switched-capacitor DC-DC converter can be achieved.

[0022] Optionally, the wireless charging circuit also includes a first thermistor and a second thermistor. The first thermistor is used to sense the temperature of the first battery. The second thermistor is used to sense the temperature of the first boost circuit and the processor. The processor is also used to control the second terminal of the regulating resistor to be left floating, grounded, or to provide a pulse width modulation signal to the second terminal of the regulating resistor based on the sensing results of the first and second thermistors. In this way, over-temperature protection for the electronic device can be achieved through the aforementioned first and second thermistors.

[0023] Another aspect of this application provides an electronic device. This electronic device includes a first coil and any of the wireless charging circuits described above. The first coil is electrically connected to a first AC-DC conversion circuit. The first coil is used to emit an alternating magnetic field, and also to receive the alternating magnetic field and induce AC current. This electronic device has the same technical effects as the wireless charging circuit provided in the foregoing embodiments, and will not be repeated here.

[0024] Optionally, the wireless charging circuit further includes a second boost circuit and a second AC-DC converter circuit. The second boost circuit is electrically connected to the first voltage conversion circuit and is used to boost the voltage of the first battery before outputting it; wherein the boost factor of the second boost circuit is less than or equal to the boost factor of the first boost circuit. The second AC-DC converter circuit is electrically connected to the second boost circuit and is used to convert the DC voltage output by the second boost circuit into an AC voltage. In addition, the electronic device also includes a second coil, electrically connected to the second AC-DC converter circuit, for emitting an alternating magnetic field. When an electronic device to be charged is located at the position of the second coil in the electronic device with this wireless charging circuit, the electronic device can reverse charge the electronic device to be charged through the charging path formed by the second boost circuit, the second AC-DC converter circuit, and the second coil.

[0025] Optionally, the electronic device includes a first battery. The first battery is electrically connected to a first voltage conversion circuit in the wireless charging circuit. The electronic device can reverse charge the electronic device to be charged by discharging the first battery.

[0026] Optionally, the electronic device also includes a circuit board and a housing, with the housing covering the circuit board and the first battery. A wireless charging circuit is disposed on the circuit board. A first coil is located on the side of the first battery facing the housing and is in contact with the housing. In this way, the electronic device to be charged can be placed on the surface of the housing away from the first coil, allowing the alternating magnetic field emitted by the first coil to be transmitted to the coil of the electronic device to be charged.

[0027] Another aspect of this application provides a wireless charging system. This wireless charging system may include a first electronic device and a second electronic device. The first electronic device may be any of the aforementioned electronic devices. The second electronic device includes a second battery, a third coil, and a third AC / DC conversion circuit. The third coil is used to emit an alternating magnetic field to the first coil in the first electronic device, or to receive an alternating magnetic field emitted by the first coil. The third AC / DC conversion circuit is electrically connected to the third coil and the second battery, and is used to convert the AC voltage induced by the third coil after receiving the AC magnetic field into a DC voltage to charge the second battery. The third AC / DC conversion circuit is also used to convert the battery voltage provided by the second battery into an AC voltage and transmit it to the third coil, causing the third coil to emit an alternating magnetic field. When the second electronic device is located at the position of the first coil of the first electronic device, the first electronic device can reverse charge the second electronic device. This wireless charging system has the same technical effects as the electronic device provided in the foregoing embodiments, and will not be repeated here.

[0028] Optionally, the first electronic device includes a second boost circuit, a second AC-DC conversion circuit, and a second coil. The second boost circuit is electrically connected to the first voltage conversion circuit in the first electronic device and is used to boost the output voltage of the first voltage conversion circuit before outputting it. The boost factor of the second boost circuit is less than or equal to the boost factor of the first boost circuit. The second AC-DC conversion circuit is electrically connected to the second boost circuit and is used to convert the DC voltage output by the second boost circuit into AC voltage. The second coil and the second AC-DC conversion circuit are used to emit an alternating magnetic field. Furthermore, the wireless charging system also includes a third electronic device. The third electronic device includes a third battery, a fourth coil, and a fourth AC-DC conversion circuit. The fourth coil is used to receive the alternating magnetic field emitted by the second coil. The fourth AC-DC conversion circuit is electrically connected to the fourth coil and the third battery, and is used to convert the AC voltage induced by the fourth coil after receiving the AC magnetic field into a DC voltage to charge the third battery. When the third electronic device is located at the position of the second coil of the first electronic device, the first electronic device can reverse charge the third electronic device.

[0029] Another aspect of this application provides a control method. This control method is applied to a processor in any of the electronic devices described above. The electronic device further includes a first battery electrically connected to the processor, and the first battery is electrically connected to a first voltage conversion circuit in a wireless charging circuit. A first boost circuit and at least one stage of switched-capacitor DC-DC converter are sequentially electrically connected between the first voltage conversion circuit and the first AC-DC conversion circuit. The method includes: after receiving a user's control operation, if the charge of the first battery is greater than a minimum charge threshold, controlling the first voltage conversion circuit to output the first battery voltage provided by the first battery. The control operation is used to control the first battery to discharge. Controlling the first boost circuit to boost the first battery voltage, and controlling the at least one stage of switched-capacitor DC-DC converter to output the voltage output by the first boost circuit. After receiving a power boost request, controlling the at least one stage of switched-capacitor DC-DC converter to boost the voltage output by the first boost circuit. Controlling the first AC-DC conversion circuit to convert the voltage output by the at least one stage of switched-capacitor DC-DC converter into an AC voltage to excite a first coil to emit an alternating magnetic field. The above control method has the same technical effects as the electronic device provided in the foregoing embodiments, and will not be repeated here.

[0030] Optionally, the wireless charging circuit further includes a second boost circuit, a second AC-DC conversion circuit, and a second coil. The second boost circuit is electrically connected to the first voltage conversion circuit. The second AC-DC conversion circuit is electrically connected to the second boost circuit. The second coil is electrically connected to the second AC-DC conversion circuit. When the charge of the first battery is greater than a minimum charge threshold, the method further includes detecting whether there is an electronic device to be charged at the location of the second coil. If there is an electronic device to be charged at the location of the second coil, after controlling the first voltage conversion circuit to output the first battery voltage provided by the first battery, the method further includes controlling the second boost circuit to boost the first battery voltage. The voltage output by the second boost circuit is less than or equal to the voltage output by the first boost circuit. The second AC-DC conversion circuit converts the DC voltage output by the second boost circuit into an AC voltage to excite the second coil to emit an alternating magnetic field. The technical effects of the second boost circuit, the second AC-DC conversion circuit, and the second coil are the same as described above and will not be repeated here.

[0031] Optionally, the wireless charging circuit further includes a first switching circuit and a second switching circuit. A first terminal of the first switching circuit is electrically connected to the input terminal of the first voltage conversion circuit, and a second terminal of the first switching circuit is electrically connected between the first boost circuit and at least one stage of a switched-capacitor DC-DC converter. A first terminal of the second switching circuit is electrically connected to the first boost circuit, and a second terminal of the second switching circuit is electrically connected to at least one stage of the switched-capacitor DC-DC converter. Before controlling the first voltage conversion circuit to output the first battery voltage provided by the first battery after receiving a user's control operation, the method includes: generating a first switching control signal and a second switching control signal according to the control operation. Next, the first switching control signal is output to the control terminal of the first switching circuit to control the first switching circuit to disconnect. Next, the second switching control signal is output to the control terminal of the second switching circuit to control the second switching circuit to conduct, electrically connecting the first boost circuit to at least one stage of the switched-capacitor DC-DC converter. At this time, reverse charging can be performed on a second electronic device located at the first coil position.

[0032] Optionally, before receiving user control operations, the control method further includes: sending a detection signal, which is used to connect the electronic device and the electronic device to be charged. Next, if the electronic device and the electronic device to be charged are successfully wirelessly connected, an instruction request message is output. The instruction request message is used to instruct the user to input the aforementioned control operation. The aforementioned control operation can be displayed in the form of an information prompt box, allowing the user to operate on the instruction request message in the information prompt box according to their needs. When the user agrees to the aforementioned instruction request message, the aforementioned control operation can be sent to the processor.

[0033] Optionally, the wireless charging circuit also includes a third switch circuit. The first terminal of the third switch circuit is electrically connected to the USB interface, and the second terminal is electrically connected to the output terminal of the second boost circuit. The USB interface is used to electrically connect to an external device and identify the type of the external device. If the USB interface is electrically connected to an external device, the method further includes: generating a third switch control signal based on the USB interface's identification result of the external device type. Next, the third switch control signal is output to the control terminal of the third switch circuit to control the third switch circuit to conduct, electrically connecting the USB interface to the second boost circuit. Next, after controlling the first voltage conversion circuit to output the first battery voltage provided by the first battery, the method further includes: controlling the second boost circuit to boost the first battery voltage and transmitting it to the external device through the third switch circuit. In this way, the voltage output by the second boost circuit can power the external device electrically connected to the USB interface to achieve data transmission.

[0034] Optionally, the wireless charging circuit also includes a fourth switching circuit. The first terminal of the fourth switching circuit is electrically connected to the output terminal of the second boost circuit, and the second terminal is electrically connected to the second AC / DC conversion circuit. After detecting that an electronic device to be charged is located at the position of the second coil, before controlling the second boost circuit to boost the voltage of the first battery, the method further includes generating a fourth switching control signal. Next, the fourth switching control signal is output to the control terminal of the fourth switching circuit to control the fourth switching circuit to conduct, electrically connecting the second boost circuit and the second AC / DC conversion circuit. The technical effect of the fourth switching circuit is the same as described above and will not be repeated here.

[0035] Optionally, before receiving user control operations, the method further includes: first, generating a second switch control signal and outputting the second switch control signal to the control terminal of the second switch circuit to control the second switch circuit to disconnect. Next, if there is a wireless charging power source at the location of the first coil, a first switch control signal is generated. Next, the first switch control signal is output to the control terminal of the first switch circuit to control the first switch circuit to conduct, electrically connecting at least one stage of switched-capacitor DC-DC converter to the input terminal of the first voltage conversion circuit. Next, the at least one stage of switched-capacitor DC-DC converter is controlled to transmit the DC voltage output by the first AC-DC conversion circuit to the first switch circuit. Next, the first voltage conversion circuit is controlled to convert the DC voltage output by the first AC-DC conversion circuit into the first battery voltage of the first battery and apply it to the first battery to charge the first battery. At this time, the wireless charging power source located at the location of the first coil can perform forward charging of the first electronic device.

[0036] Optionally, the wireless charging circuit further includes a first switching circuit and a fifth switching circuit. The first terminal of the first switching circuit is electrically connected to the input terminal of the first voltage conversion circuit, and the second terminal of the first switching circuit is electrically connected between the first boost circuit and at least one stage of switched-capacitor DC-DC converter. The first terminal of the fifth switching circuit is electrically connected to a USB interface, and the second terminal is electrically connected to the input terminal of the first voltage conversion circuit. The USB interface is used to electrically connect to an external device and identify the type of the external device. If the USB interface is electrically connected to a charging power source, the method further includes: generating a first switch control signal and a fifth switch control signal based on the identification result of the external device type by the USB interface. Next, the first switch control signal is output to the control terminal of the first switching circuit to control the first switching circuit to disconnect. Next, the fifth switch control signal is output to the control terminal of the fifth switching circuit to control the fifth switching circuit to conduct, electrically connecting the USB interface to the input terminal of the first voltage conversion circuit, and the power supply voltage provided by the external device is transmitted to the input terminal of the first voltage conversion circuit through the fifth switching circuit. The technical effect of the fifth switching circuit is the same as described above and will not be repeated here.

[0037] Optionally, the wireless charging circuit also includes a first thermistor for sensing the temperature of the first battery. After controlling the first AC-DC conversion circuit to convert the DC voltage output from the second voltage conversion circuit into AC voltage, the method further includes: based on the sensing result of the first thermistor, if the temperature of the first battery is greater than a first temperature threshold, controlling at least one stage of switched-capacitor DC-DC converter to output the voltage output by the first boost circuit. If the temperature of the first battery is less than the first temperature threshold, controlling at least one stage of switched-capacitor DC-DC converter to maintain the boosting state of the voltage output by the first boost circuit. This provides over-temperature protection for the first electronic device.

[0038] Optionally, if the temperature of the first battery exceeds a first temperature threshold, and the second voltage conversion circuit outputs the voltage from the first boost circuit, the method further includes: if the temperature of the first battery exceeds a second temperature threshold, shutting down the first boost circuit. The second temperature threshold is greater than the first temperature threshold. This provides secondary over-temperature protection for the first electronic device.

[0039] Optionally, the method further includes: if the charge level of the first battery is less than a minimum charge threshold, shutting down the first boost circuit and outputting a low charge indication message. This low charge indication message indicates that the charge level of the first battery is less than the minimum charge threshold. This allows for undervoltage lockout of the first electronic device.

[0040] Optionally, the first boost circuit has a feedback terminal. The second voltage conversion circuit further includes a pull-up resistor, a pull-down resistor, and a regulating resistor. The first terminal of the pull-up resistor is electrically connected to the output terminal of the first boost circuit, and the second terminal is electrically connected to the feedback terminal of the first boost circuit. The first terminal of the pull-down resistor is electrically connected to the feedback terminal of the first boost circuit, and the second terminal is grounded; the first terminal of the regulating resistor is electrically connected to the feedback terminal of the first boost circuit. Before controlling the first boost circuit to boost the first battery voltage and controlling at least one switched-capacitor DC-DC converter to output the voltage output by the first boost circuit, the method further includes: controlling the second terminal of the regulating resistor to be left floating. This allows for low-power charging of the electronic device to be charged.

[0041] Optionally, after receiving a power boost request, before controlling at least one switched-capacitor DC-DC converter to boost the voltage output of the first boost circuit, the method further includes: grounding the second terminal of the regulating resistor. This allows for high-power charging of the electronic device to be charged. In this case, the voltage output of the first boost circuit is a fixed value.

[0042] Optionally, after receiving a power boost request and before controlling at least one switched-capacitor DC-DC converter to boost the voltage output of the first boost circuit, the method further includes: providing a pulse width modulation signal to the second terminal of the regulating resistor. This allows for high-power charging of the electronic device to be charged. At this time, the voltage output of the first boost circuit can be adjusted according to the duty cycle of the pulse width modulation signal, enabling the first boost circuit to operate at the peak of voltage conversion and improving the voltage conversion efficiency of the first boost circuit.

[0043] Another aspect of this application provides a computer-readable storage medium comprising computer instructions that, when executed on a processor in an electronic device, cause the processor to perform any of the control methods described above.

[0044] Another aspect of this application provides a computer program product including computer instructions that, when executed on a processor in an electronic device, cause the processor to perform any of the control methods described above. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of a wireless charging system provided in an embodiment of this application;

[0046] Figure 2 This is a schematic diagram of the structure of a second electronic device provided in an embodiment of this application;

[0047] Figure 3 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0048] Figure 4 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0049] Figure 5 A schematic diagram of the output current versus charging efficiency provided for an embodiment of this application;

[0050] Figure 6 A schematic diagram of power versus charging efficiency provided for an embodiment of this application;

[0051] Figure 7 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0052] Figure 8A This is a schematic diagram of the structure of a first electronic device provided in an embodiment of this application;

[0053] Figure 8B A schematic diagram of a wireless reverse charging method provided in an embodiment of this application;

[0054] Figure 9A flowchart illustrating a charging control method for an electronic device provided in an embodiment of this application;

[0055] Figure 10 This is a schematic diagram of the structure of another first electronic device provided in an embodiment of this application;

[0056] Figure 11A This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0057] Figure 11B for Figure 11A A schematic diagram of the control process of a wireless charging system;

[0058] Figure 12 for Figure 11A Another control process diagram of the wireless charging system in the diagram;

[0059] Figure 13A This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0060] Figure 13B for Figure 13A A schematic diagram of the control process of a wireless charging system;

[0061] Figure 13C for Figure 13A Another control process diagram of the wireless charging system in the diagram;

[0062] Figure 14A for Figure 13A Another control process diagram of the wireless charging system in the diagram;

[0063] Figure 14B for Figure 13A Another control process diagram of the wireless charging system in the diagram;

[0064] Figure 14C A schematic diagram of the display interface of an electronic device provided in an embodiment of this application;

[0065] Figure 14D A schematic diagram of the display interface of another electronic device provided in an embodiment of this application;

[0066] Figure 15 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0067] Figure 16 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0068] Figure 17A for Figure 16 A schematic diagram of a switched capacitor DC-DC converter;

[0069] Figure 17B for Figure 17A A schematic diagram of a control process for a switched capacitor DC-DC converter.

[0070] Figure 18A for Figure 17A A schematic diagram of a control process for a switched capacitor DC-DC converter.

[0071] Figure 18B for Figure 18A The equivalent circuit diagram of the circuit structure shown;

[0072] Figure 19A for Figure 17A A schematic diagram of a control process for a switched capacitor DC-DC converter.

[0073] Figure 19B for Figure 19A The equivalent circuit diagram of the circuit structure shown;

[0074] Figure 20A for Figure 16 Another schematic diagram of a switched capacitor DC-DC converter;

[0075] Figure 20B for Figure 20A A schematic diagram of a control process for a switched capacitor DC-DC converter.

[0076] Figure 20C for Figure 20A A schematic diagram of another control process for a switched capacitor DC-DC converter;

[0077] Figure 21 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0078] Figure 22A This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0079] Figure 22B for Figure 22A A schematic diagram of a specific structure;

[0080] Figure 23 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0081] Figure 24 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0082] Figure 25 A schematic diagram illustrating another wireless reverse charging method provided in an embodiment of this application;

[0083] Figure 26A flowchart illustrating another charging control method for an electronic device provided in this application embodiment;

[0084] Figure 27 This is a schematic diagram of another wireless charging system provided in an embodiment of this application;

[0085] Figure 28 A schematic diagram of a control process for a wireless charging system provided in an embodiment of this application;

[0086] Figure 29 This is a schematic diagram of another control process of the wireless charging system provided in an embodiment of this application;

[0087] Figure 30 This is a schematic diagram of another control process of the wireless charging system provided in an embodiment of this application;

[0088] Figure 31 This is a schematic diagram of another control process of the wireless charging system provided in an embodiment of this application.

[0089] Figure label:

[0090] 01-Wireless charging system; 10-First electronic device; 20-Second electronic device; 30-Wireless charging circuit; 301-First voltage conversion circuit; 302-Second voltage conversion circuit; 311-First AC-DC conversion circuit; 321-First coil; 100-First battery; 200-Second battery; 323-Third coil; 313-Third AC-DC conversion circuit; 31-First boost circuit; 33-Switched capacitor DC-DC converter; 330-Processor; 11-Display screen; 12-Carrier plate; 13-Housing; 40-Charging power supply; 20-Second battery Sub-device; 34-First switching circuit; 35-Second switching circuit; 36-Fifth switching circuit; 41-Wireless charging power supply; 61-First thermistor; 62-Second thermistor; 37-Third switching circuit; 38-Fourth switching circuit; 32-Second boost circuit; 312-Second AC-DC conversion circuit; 322-Second coil; 30-Third electronic device; 324-Fourth coil; 314-Fourth AC-DC conversion circuit; 300-Third battery; 50-USB interface; 51-Third boost circuit; 52-Control button; 53-Information prompt box. Detailed Implementation

[0091] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0092] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0093] Furthermore, in this application, directional terms such as "upper" and "lower" may be defined relative to the orientation in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation in which the components are placed in the accompanying drawings.

[0094] In this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "electrical connection" can be a direct electrical connection or an indirect electrical connection through an intermediate medium.

[0095] This application provides an embodiment of, as follows: Figure 1 The wireless charging system 01 shown here may include a first electronic device 10 and a second electronic device 20. The first electronic device 10 may be charged via a wired connection to a charging power source or via a wireless charging power source. For ease of description, the charging process of the first electronic device 10 will be referred to as forward charging. Furthermore, when the first electronic device 10 has sufficient power, it can charge the second electronic device 20 via wireless power transfer. The process of the first electronic device 10 wirelessly charging the electronic device to be charged, such as the second electronic device 20, will be referred to as wireless reverse charging.

[0096] The aforementioned first electronic device 10 may include a wireless charging dock, a tablet computer, a laptop (e.g., an ultra-thin or portable model), a mobile phone, a wireless charging electric vehicle, a wireless charging small home appliance (e.g., a soymilk maker, a robot vacuum cleaner), or other electronic products with wireless reverse charging capabilities. This application does not impose any special limitations on the specific form of the aforementioned first electronic device 10. Tablet computers generally offer better portability, and compared to mobile phones, they typically have larger battery capacities, for example, exceeding 10,000 mAh. For ease of explanation, the following description uses the first electronic device 10 as an example. Figure 1 The following explanation uses a tablet computer as an example.

[0097] In some embodiments of this application, the second electronic device 20 can be an electronic device with a relatively high charging power (≥5W), such as... Figure 1 The phone shown, or, Figure 2 The tablet computer shown in (a) is an example. Alternatively, in some other embodiments of this application, the second electronic device 20 described above may also be an electronic device with lower charging power (<5W), such as... Figure 2 The smartwatch (or smart bracelet) shown in (b) above, such as Figure 2 The wireless mouse shown in (c) is as follows: Figure 2 The wireless earphone shown in (d) is as follows: Figure 2 The stylus shown in (e) is as follows: Figure 2 The leather case with a keyboard shown in (f) above, or as shown in [the image] Figure 2 The battery-loaded leather case shown in (g) is shown in the image.

[0098] Among them, such as Figure 2 The leather case with a keyboard shown in (f) can be installed on a mobile phone or tablet. When the keyboard on the case is powered on, the user can control the mobile phone or tablet inside the case by operating the keyboard. Figure 2 When the battery-equipped case shown in (g) is installed on a mobile phone or tablet, the battery in the case can charge the mobile phone or tablet installed inside the case.

[0099] In order to enable the electronic device provided in this application embodiment, such as the first electronic device 10 described above, to charge the second electronic device 20 via wireless power transfer, such as... Figure 3 As shown, the first electronic device 10 may include a wireless charging circuit 30 and a first battery 100. The wireless charging circuit 30 includes circuit structures such as a first voltage conversion circuit 301, a second voltage conversion circuit 302, and a first AC-DC conversion circuit 311. The wireless charging circuit can be integrated into a chip. Furthermore, the first electronic device 10 may also include a first coil 321.

[0100] In some embodiments of this application, the first voltage conversion circuit 301 described above can be a buck circuit. The first voltage conversion circuit 301 is electrically connected to the first battery 100. When the first battery 100 needs to be charged, the first voltage conversion circuit 301 can transmit the power supply voltage Vin (e.g., 5V) provided by the charging power source (not shown in the figure) to the first voltage conversion circuit 301. The first voltage conversion circuit 301 is used to step down the power supply voltage Vin to convert it into the first battery voltage Vbat (e.g., 3.4V to 4.4V) of the first battery 100 for charging.

[0101] Furthermore, when the first electronic device 10 needs to charge the second electronic device 20, the first voltage conversion circuit 301 is also used to output the first battery voltage Vbat1 (e.g., the aforementioned 3.4V to 4.4V) provided by the first battery 100. For example, a switching transistor (not shown in the figure) may be provided in the first voltage conversion circuit 301. The first terminal (e.g., source) and the second terminal (e.g., drain) of the switching transistor are electrically connected to the first battery 100 and the output terminal of the first voltage conversion circuit 301, respectively. When the gate of the switching transistor is turned on, the first battery voltage Vbat1 provided by the first battery 100 can be transmitted to the output terminal of the first voltage conversion circuit 301 through the aforementioned switching transistor.

[0102] During the wireless reverse charging process of the first electronic device 10 to the second electronic device 20, the greater the charging power output of the first electronic device 10, the faster the wireless reverse charging speed and the higher the charging efficiency. The charging power W (W = I × V) of the first electronic device 10 is directly proportional to the charging current I and the charging voltage V of the first electronic device 10. When the charging current I is increased, due to the power loss P... loss (P loss =I 2 The impedance R is proportional to the square of the charging current I. Therefore, with the charging path impedance R between the first electronic device 10 and the second electronic device 20 remaining constant, the larger the charging current I, the greater the power loss. Thus, this application can increase the charging power W output by the first electronic device 10 by increasing the charging voltage V of the first electronic device 10.

[0103] Therefore, in order to increase the charging power W output by the first electronic device 10 and thus improve the efficiency of reverse charging, the wireless charging circuit 30 of the first electronic device 10 is provided with the following... Figure 3 The second voltage conversion circuit 302 is shown. This second voltage conversion circuit 302 is electrically connected to the first voltage conversion circuit 301. The second voltage conversion circuit 302 is used to boost the voltage output by the first voltage conversion circuit 301, thereby increasing the charging voltage V of the first electronic device 10 and thus increasing the charging power W output by the first electronic device 10.

[0104] It should be noted that the voltage output by the first voltage conversion circuit 301 can be the voltage after the first voltage conversion circuit 301 steps down the power supply voltage Vin when the first voltage conversion circuit 301 is electrically connected to the charging power supply used to provide the power supply voltage Vin. Alternatively, the voltage output by the first voltage conversion circuit 301 can be the first battery voltage Vbat1 output by the first battery 100.

[0105] Therefore, the second voltage conversion circuit 302 is also electrically connected to the first AC-DC conversion circuit 311. The first AC-DC conversion circuit 311 converts the DC voltage output by the second voltage conversion circuit 302 into an AC voltage. The first coil 321 can be electrically connected to the first AC-DC conversion circuit 311. The first coil 321, upon receiving the AC voltage output by the first AC-DC conversion circuit 311, can emit an alternating magnetic field.

[0106] It should be noted that the AC-DC conversion circuit provided in this application embodiment can be a bridge circuit mainly composed of multiple switching transistors, such as a full-bridge circuit. This bridge circuit can convert DC voltage into AC voltage, and vice versa.

[0107] In addition, such as Figure 3 As shown, the second electronic device 20 includes a second battery 200, a third coil 323, and a third AC-DC conversion circuit 313. The third coil 323 can receive the alternating magnetic field emitted by the first coil 321 and induce an AC voltage. The third AC-DC conversion circuit 313 is electrically connected to the third coil 323 and the second battery 200. This third AC-DC conversion circuit 313 can be used to convert the AC voltage induced by the third coil 323 after receiving the AC magnetic field into a DC voltage, and transmit the DC voltage to the second battery 200 to charge the second battery 200. In this way, a wireless reverse charging process can be realized from the first electronic device 10 to the second electronic device 20.

[0108] As described above, the second voltage conversion circuit 302 can over-boost the voltage output by the first voltage conversion circuit 301, thereby increasing the peak voltage of the AC voltage generated on the first coil 321, and ultimately achieving the purpose of increasing the charging voltage V provided by the first electronic device 10 to the second electronic device 20. The structure of the second voltage conversion circuit 302 will be described below.

[0109] In some embodiments of this application, such as Figure 4 As shown, the second voltage conversion circuit 302 may include a first boost circuit 31. When the first boost circuit 31 is working, it can boost the input first battery voltage Vbat before outputting it. At this time, the output voltage of the first boost circuit 31 is greater than the input voltage.

[0110] The first boost circuit 31 is a DC-DC voltage converter with an internal inductor. Due to the presence of the inductor, the boost circuit experiences power loss P during the boost process. loss (P loss =△U 2 / R) is proportional to the square of the difference ΔU between the output voltage and the input voltage of the boost circuit.

[0111] For example, when the input voltage of the boost circuit is the same, such as Figure 5 As shown, curves ①, ②, and ③ represent the voltage conversion efficiency versus output current of the boost circuit when the output voltage is 5V, 9V, and 12V, respectively. From these three curves, it can be seen that the higher the output voltage of the boost circuit, the greater the difference between the output voltage and the input voltage ΔU, and the lower the voltage conversion efficiency of the boost circuit.

[0112] For example, when the output voltage Vout of the preset second voltage conversion circuit 302 is 12V, if the first boost circuit 31 directly converts the first battery voltage Vbat (e.g., 3.7V) to 12V, ΔU = 8.3V. At this time, by... Figure 6 As shown in curve ①, the voltage conversion efficiency corresponding to the highest power of 12W in the first boost circuit 31 is 80%, which is relatively low. This will cause the inductor in the first boost circuit 31 to generate significant heat, and the temperature of the first boost circuit 31 can rise to 144℃.

[0113] Therefore, in the second voltage conversion circuit 302 provided in this application embodiment, in order to improve the voltage conversion efficiency of the first boost circuit 31, the difference ΔU between the output voltage and the input voltage of the first boost circuit 31 can be appropriately reduced, so that the first boost circuit 31 operates at the peak voltage conversion efficiency position or is located near the peak voltage conversion efficiency.

[0114] For example, when the output voltage Vout of the preset second voltage conversion circuit 302 is 12V, the first boost circuit 31 can convert the first battery voltage Vbat (e.g., 3.7V) to 6V, ΔU = 2.3V. Compared to the scheme of directly boosting to 12V, the difference ΔU between the output voltage and the input voltage of the first boost circuit 31 can be reduced by 6V (8.3V - 2.3V = 6V). At this time, the maximum output power of the first boost circuit 31 can be increased to 18W. Furthermore, when the maximum output power of the first boost circuit 31 is 12W, its voltage conversion efficiency can be 92%, and the voltage conversion efficiency is effectively improved. This reduces the inductor heating phenomenon in the first boost circuit 31, keeping the temperature of the first boost circuit 31 at around 86.4℃.

[0115] However, when the difference ΔU between the output voltage and input voltage of the first boost circuit 31 is reduced, in order to ensure that the output voltage Vout of the second voltage conversion circuit 302 remains at 12V and that the second voltage conversion circuit 302 has high voltage conversion efficiency, such as... Figure 4As shown, the second voltage conversion circuit 302 may further include at least one stage of switched capacitor DC-DC converter (charge pump) 33 electrically connected to the first boost circuit 31.

[0116] The switched-capacitor DC transformer 33 mainly consists of multiple switching transistors and capacitors that enable fast charging ("flying"). For example, the switching transistors can be metal-oxide-semiconductor field-effect transistors (MOSFETs). These MOSFETs can operate at a switching frequency of 1–2 MHz, thus exhibiting high switching speed, which is beneficial for improving the voltage conversion efficiency of the switched-capacitor DC transformer 33. Furthermore, the capacitors in the switched-capacitor DC transformer 33 can be small-sized, low-cost multilayer ceramic capacitors (MLCCs).

[0117] The switched-capacitor DC-DC converter 33 has no internal inductor, making it an inductive DC-DC voltage converter. Therefore, the capacitor can be charged and discharged by controlling the on / off state of the switching transistor in the switched-capacitor DC-DC converter 33, achieving the purpose of boosting the input voltage. Since the switched-capacitor DC-DC converter 33 has no inductor, its voltage conversion efficiency is relatively high, reaching approximately 97%, resulting in a voltage conversion efficiency of 89.24% (92% × 97% = 89.24%) for the entire second voltage conversion circuit 302. Based on this, as... Figure 6 As shown, curve ① represents the scheme where the first battery voltage Vbat (e.g., 3.7V) is converted to 12V using only the first boost circuit 31, and curve ② represents the scheme where the first battery voltage Vbat (e.g., 3.7V) is converted to 12V using a second voltage conversion circuit 302 composed of the first boost circuit 31 and at least one switched capacitor DC-DC converter 33. The difference between curve ① and curve ② shows that the voltage conversion efficiency of the scheme in curve ② can be improved by up to 11%. Therefore, the electronic device provided in this application embodiment can provide higher charging power and improve the charging speed of wireless reverse charging during the wireless reverse charging process of the electronic device to be charged.

[0118] Furthermore, since no inductor is included in the switched-capacitor DC transformer 33, its size is relatively small, resulting in higher power density (power provided per unit area of ​​the electronic device) and lower equivalent series resistance (ESR). Additionally, the absence of an inductor in the switched-capacitor DC transformer 33 leads to lower noise and less electromagnetic interference (EMI) to radio frequency (RF) circuits.

[0119] It should be noted that the embodiments of this application do not limit the sequential positional relationship between the first boost circuit 31 and the switched capacitor DC transformer 33 in the second voltage conversion circuit 302. For example, it can be as follows... Figure 4 As shown, the first boost circuit 31 and at least one switched-capacitor DC-DC converter 33 can be sequentially electrically connected between the first voltage conversion circuit 301 and the first AC-DC conversion circuit 311. Since the switched-capacitor DC-DC converter 33 is located at the output terminal of the first boost circuit 31, the voltage input from the first boost circuit 31 to the switched-capacitor DC-DC converter 33 is greater than the voltage at the input terminal of the first boost circuit 31. Therefore, the withstand voltage requirement of the switching transistor in the switched-capacitor DC-DC converter 33 is higher than that of the switching transistor in the first boost circuit 31, thereby reducing the withstand voltage requirement of the switching transistor in the first boost circuit 31.

[0120] Alternatively, in some other embodiments of this application, it can be as follows: Figure 7 As shown, at least one switched-capacitor DC-DC converter 33 and a first boost circuit 31 can be electrically connected sequentially between a first voltage conversion circuit 301 and a first AC-DC conversion circuit 311. In this case, since the switched-capacitor DC-DC converter 33 is located at the input terminal of the first boost circuit 31, the voltage input from the first voltage conversion circuit 301 to the switched-capacitor DC-DC converter 33 is less than the voltage at the input terminal of the first boost circuit 31. Therefore, the withstand voltage requirement of the switching transistor in the first boost circuit 31 is higher than that of the switching transistor in the switched-capacitor DC-DC converter 33.

[0121] For ease of explanation, the following will all use the format of... Figure 4 The following description uses the example of a first boost circuit 31 and at least one switched capacitor DC-DC converter 33 being electrically connected in sequence between a first voltage conversion circuit 301 and a first AC-DC conversion circuit 311.

[0122] The following example illustrates the positions of the wireless charging circuit 30 and the first battery 100 within the first electronic device 10. For example, as... Figure 8AAs shown, the first electronic device 10 may further include: a display screen 11, a carrier plate 12, a housing 13, and a printed circuit board (PCB), which can be simply referred to as a circuit board. The PCB and the first battery 100 may be disposed on the surface of the carrier plate 12 near the housing 13.

[0123] It should be noted that the aforementioned display screen 11 can be a liquid crystal (LC) display screen or an organic light emitting diode (OLED) display screen capable of self-illumination. This application does not limit it in this regard.

[0124] Based on this, the first voltage conversion circuit 301, the second voltage conversion circuit 302, and the first AC-DC conversion circuit 311 in the aforementioned wireless charging circuit 30 can be mounted on a PCB. Furthermore, the first coil 321 in the first electronic device 10 can be located on the side of the first battery 100 facing the housing 13 and in contact with the housing 13. In this way, when the first electronic device 10 charges the electronic device to be charged, such as the aforementioned second electronic device 20, ... Figure 8B As shown, the second electronic device 20 can be placed on the back of the housing 13 of the first electronic device 10. This allows the first coil 321 in the first electronic device 10 (as shown) to... Figure 8A The alternating magnetic field emitted by (as shown) can be transmitted to the third coil 323 in the second electronic device 20 (e.g., Figure 4 (As shown), this achieves the purpose of wireless reverse charging.

[0125] Based on this, the aforementioned first electronic device 10 may further include components electrically connected to the wireless charging circuit 30 and the first battery 100, such as... Figure 4 The processor 330 shown is a central processing unit (CPU) or a system-on-a-chip (SoC). The following is in conjunction with... Figure 4 The structure of the wireless charging system 01 shown is illustrated by example, illustrating the method by which the processor 330 controls the first electronic device 10 to wirelessly reverse charge the second electronic device 20 and to forward charge the first battery 100 in the first electronic device 10. The control method of the processor is as follows: Figure 9 As shown, it may include S101 to S112.

[0126] S101. Determine whether the charge level of the first battery 100 is less than the minimum charge threshold Qth.

[0127] When the charge of the first battery 100 is less than the minimum charge threshold Qth, the following step S102 can be executed; when the charge of the first battery 100 is greater than the minimum charge threshold Qth, the following step S103 can be executed. The minimum charge threshold Qth can be the charge level of the first battery 100 when its battery voltage is 3.4V.

[0128] S102, Send charging command.

[0129] The charging command instructs the first electronic device 10 to issue a low battery indication message, indicating that the charge level of the first battery 100 is below a minimum charge threshold. This low battery indication message can be a graphic or text message displayed on the screen of the first electronic device 10. Alternatively, it can be a low battery warning sound emitted by the first electronic device 10. When the user receives the low battery indication message, the first electronic device 10 can be forward-charged using a charging power supply. The following example illustrates the forward charging process of the first battery 100 using a second voltage conversion circuit 302 with a single-stage switched-capacitor DC-DC converter 33.

[0130] In some embodiments of this application, the first electronic device 10 described above may include, for example: Figure 10 The Universal Serial Bus (USB) interface 50 is shown. In this case, a charging power supply 40 (e.g., an adapter) for providing the power supply voltage Vin can be electrically connected to the first voltage conversion circuit 301 in the first electronic device 10 via the USB interface. Furthermore, the processor 330 can be electrically connected to the first voltage conversion circuit 301, thereby controlling the first voltage conversion circuit 301 to convert the power supply voltage Vin into the first battery voltage Vbat1 of the first battery 100 for charging the first battery 100. The charging power supply 40 can be used to convert 220V AC power into the power supply voltage Vin (e.g., 5V).

[0131] Alternatively, in some other embodiments of this application, such as Figure 11A As shown, a wireless charging power supply 41, such as a wireless charging dock, can be used to charge the first electronic device 10 via wireless power transfer. This wireless charging power supply 41 includes a coil and an AC / DC conversion circuit. Furthermore, the wireless charging circuit in the first electronic device 10 also includes a first switching circuit 34.

[0132] For example, the control terminal g of the first switching circuit 34 can be connected to the processor 330 (e.g., Figure 4The circuit is electrically connected (as shown) to receive the first switch control signal SEN1 from the processor 330. The first terminal a of the first switch circuit 34 is electrically connected to the input terminal of the first voltage conversion circuit 301. Furthermore, the switched-capacitor DC-DC converter 33 is electrically connected between the second terminal b of the first switch circuit 34 and the first AC-DC conversion circuit 311. The first switch circuit 34 is used to turn on or off according to the first switch control signal SEN1.

[0133] In this case, when the wireless charging power supply 41 is positioned at the location of the first coil 321 of the first electronic device 10, the AC-DC conversion circuit in the wireless charging power supply 41 can convert the DC voltage of the battery into AC voltage and transmit it to the coil to generate an alternating magnetic field. Furthermore, the first coil 321 is also used to receive this alternating magnetic field and induce an AC voltage, and the first AC-DC conversion circuit 311 is also used to convert the AC voltage induced by the first coil 321 into a DC voltage.

[0134] Based on this, the control method of the processor 330 includes: outputting a first switch control signal SEN1 to the control terminal g of the first switch circuit 34 to control the first switch circuit 34 to conduct, and electrically connecting the switched capacitor DC converter 33, which is electrically connected between the second terminal b of the first switch circuit 34 and the first AC-DC conversion circuit 311, to the input terminal of the first voltage conversion circuit 301. Furthermore, the switched capacitor DC converter 33, which is electrically connected between the second terminal b of the first switch circuit 34 and the first AC-DC conversion circuit 311, is controlled to operate in bypass mode. In this mode, the switched capacitor DC converter 33 acts as a wire, which can be connected along... Figure 11B The arrow indicates that the DC voltage output from the first AC-DC conversion circuit 311 is transmitted to the first switching circuit 34.

[0135] Furthermore, since the first switching circuit 34 is in the ON state, the DC voltage output by the first AC-DC conversion circuit 311 serves as the aforementioned power supply voltage Vin, flowing along... Figure 11B As indicated by the arrow, the voltage is transmitted through the first switching circuit 34 to the input terminal of the first voltage conversion circuit 301. In this way, under the control of the processor 330, the first voltage conversion circuit 301 can convert the power supply voltage Vin into the first battery voltage Vbat1 of the first battery 100 to charge the first battery 100.

[0136] When the wireless charging power supply 41 is forward charging the first electronic device 10, since the first electronic device 10 cannot reverse charge other electronic devices to be charged, the processor 330 can control the first boost circuit 31 in the second voltage conversion circuit 302 to be in a closed state. Furthermore, to prevent damage to the switching transistor in the first boost circuit 31 caused by a large DC voltage output from the first AC-DC conversion circuit 311 after passing through the switched capacitor DC-DC converter 33 when the voltage withstand capability of the switching transistor in the first boost circuit 31 is weak, the wireless charging circuit in the first electronic device 10 may also include, for example... Figure 11A The second switching circuit 35 is shown. The control terminal g of the second switching circuit 35 is connected to the processor 330 (e.g., Figure 4 (As shown) is electrically connected to receive the second switch control signal SEN2 issued by the processor 330. The first terminal a of the second switch circuit 35 can be electrically connected to the first boost circuit 31, and the second terminal b of the second switch circuit 35 is electrically connected to at least one stage of switched-capacitor DC-DC converter 33. The second switch circuit 35 is used to turn on or off according to the second switch control signal SEN2.

[0137] The second switching circuit 35 is in an off state by default. The processor 330 outputs the second switching control signal SEN2 to the control terminal g of the second switching circuit 35 to control the second switching circuit 35 to be in the off state. In this way, the first electronic device 10 will not perform reverse charging in the default state, thus ensuring that the power of the first electronic device 10 is controllable. Furthermore, when the wireless charging power supply 41 performs forward charging on the first electronic device 10, the processor 330 can output the second switching control signal SEN2 to the control terminal g of the second switching circuit 35 to control the second switching circuit 35 to be in the off state. Figure 11B The switch capacitor DC-DC converter 33 is in the off state, as shown. This avoids the switching capacitor DC-DC converter 33 from being in the off state during the aforementioned forward charging process. Figure 11B The DC voltage output in the direction of the arrow is too high, which damages the switching transistor in the first boost circuit 31.

[0138] It should be noted that, for ease of explanation in the embodiments of this application, an "×" sign is added to the switch circuit in the off state in the accompanying drawings.

[0139] The above is based on Figure 11AThe following example illustrates the connection method of the second terminal b of the first switching circuit 34, where the switched-capacitor DC-DC converter 33 is electrically connected between the second terminal b of the first switching circuit 34 and the first AC-DC conversion circuit 311. As described above, when the wireless charging power supply 41 charges the first electronic device 10, the switched-capacitor DC-DC converter 33 operates in bypass mode, equivalent to a wire. At this time, the switched-capacitor DC-DC converter 33 itself has a certain resistance, causing the DC voltage output from the first AC-DC conversion circuit 311 to decrease after passing through the switched-capacitor DC-DC converter 33. This reduces the withstand voltage of the switching transistor in the first switching circuit 34 used to receive the DC voltage.

[0140] Alternatively, as another example, the first electronic device 10 includes, Figure 12 In the case of the first switching circuit 34 shown, the connection method between the control terminal g and the first terminal a of the first switching circuit 34 is the same as... Figure 11A Same. The difference lies in, for example Figure 12 As shown, the second terminal b of the first switching circuit 34 is electrically connected between the first AC-DC conversion circuit 311 and the switched capacitor DC converter 33. In this way, when the wireless charging power supply 41 performs forward charging on the first electronic device 10, the DC voltage output by the first AC-DC conversion circuit 311 can be... Figure 12 The signal is transmitted directly to the first switching circuit 34 in the direction of the arrow, without passing through the first switching circuit 34 again. At this time, the voltage withstand requirement of the switching transistor in the first switching circuit 34 is relatively high.

[0141] It should be noted that this application does not limit the connection method of the second terminal b of the first switch power circuit 34, and it can be any of the following: Figure 11A The method shown can also be used as follows: Figure 12 The following explanation uses the method shown below for ease of explanation. Figure 11A The following is an example of the method shown.

[0142] As can be seen from the above, when the first electronic device 10 is being forward-charged, it can be done as follows: Figure 10 As shown, a wired connection is used so that the charging power supply 40 (e.g., an adapter) can positively charge the first electronic device 10 via a USB interface. Alternatively, it can also be as follows: Figure 11A As shown, the first electronic device 10 is wirelessly charged via a wireless charging power source 41 (e.g., a charging dock). Therefore, to avoid conflicts between wireless charging and wireless forward charging, the wireless charging circuit in the first electronic device 10 may further include, for example... Figure 13A The fifth switching circuit 36 ​​is shown. The control terminal g of the fifth switching circuit 36 ​​is connected to the processor 330 (e.g., Figure 4The circuit is electrically connected to the processor 330 to receive the fifth switch control signal SEN5. The first terminal a of the fifth switch circuit 36 ​​is electrically connected to the USB interface 50, and the second terminal b of the fifth switch circuit 36 ​​is electrically connected to the input terminal of the first voltage conversion circuit 301. The fifth switch circuit 36 ​​is used to turn on or off according to the fifth switch control signal SEN5.

[0143] In this case, such as Figure 13B As shown, when the USB interface 50 is electrically connected to an external device, it identifies the type of that external device. For example, when the USB interface 50 is a Type-C interface, the Type-C interface is equipped with a CC pin as specified in the Type-C interface protocol. The CC pin can identify the type of the connected external device.

[0144] If the USB port recognizes the external device as a charging power supply 40, the charging power supply 40 can perform forward charging on the first electronic device 10. At this time, the control method of the processor 330 may include: First, the processor 330 can generate the first switch control signal SEN1 and the fifth switch control signal SEN5 based on the identification result of the external device type by the USB interface 50. Next, the processor 330 can output the first switch control signal SEN1 to the control terminal g of the first switch circuit 34, controlling the first switch circuit 34 to be in an off state. Furthermore, the processor 330 outputs the fifth switch control signal SEN5 to the control terminal g of the fifth switch circuit 36, controlling the fifth switch circuit 36 ​​to be turned on, electrically connecting the USB interface 50 to the input terminal of the first voltage conversion circuit 301, so that the power supply voltage Vin provided by the charging power supply 40 is... Figure 13B The direction of the arrow in the signal is transmitted to the input of the first voltage conversion circuit 301 via the fifth switch circuit 36 ​​to charge the first battery 100. At this time, the processor 330 can control the second switch circuit 35 as follows: Figure 13B It is currently in an off state.

[0145] Or, such as Figure 13CAs shown, when the first electronic device 10 is being forward-charged using a wireless charging power supply 41, the control method of the processor 330 may include: if a wireless charging power supply 41 (e.g., a wireless charging dock) is present at the location of the first coil 321, then a first switch control signal SEN1 and a fifth switch control signal SEN5 are generated. For example, when the first electronic device 10 is located on the wireless charging power supply 41, which serves as a wireless charging dock, the wireless charging power supply 41 can communicate wirelessly with the first electronic device 10, thereby enabling the wireless charging power supply 41 to send an presence signal to the processor 330 of the first electronic device 10, so that the processor 330 generates the first switch control signal SEN1 and the fifth switch control signal SEN5 based on the presence signal.

[0146] Next, the processor 330 can output a first switch control signal SEN1 to the control terminal g of the first switch circuit 34, controlling the first switch circuit 34 to be in the on state. Furthermore, it can output a fifth switch control signal SEN5 to the control terminal g of the fifth switch circuit 36, controlling the fifth switch circuit 36 ​​to be in the off state. Additionally, the processor 330 can control the second switch circuit 35 as follows: Figure 13B The device is in the off state. At this time, the voltage provided by the wireless charging power supply 41 can flow along... Figure 13C The direction of the arrow in the circuit is transmitted through the first switching circuit 34 to the input terminal of the first voltage conversion circuit 301. The first voltage conversion circuit 301 can convert the DC voltage output by the first AC-DC conversion circuit 311 into the first battery voltage of the first battery 100 and apply it to the first battery 100 to charge the first battery 100.

[0147] By charging the first electronic device 10 in the above manner, the charge level of the first battery 100 can be made greater than the minimum charge threshold Q. Lth At this point, the following can be executed: Figure 9 S103 is shown.

[0148] S103, turn on the second switch circuit 35.

[0149] As described above, to ensure the controllable power of the first electronic device 10, the second switching circuit 35 is in a default off state before executing S103. Based on this, taking a tablet computer as an example, to facilitate user control over when the first electronic device 10 performs reverse charging, in some embodiments of this application, such as... Figure 14C As shown, the display interface of the first electronic device 10 can be equipped with a corresponding reverse charging control button 52. When the charge of the first battery 100 is greater than the minimum charge threshold Q... LthAt this time, the user can trigger the aforementioned reverse charging control button 52 to perform a control operation, which is used to control the discharge of the first battery 100 in the first electronic device 10.

[0150] Next, the processor 330 in the first electronic device 10 receives the aforementioned control operation from the user and generates a first switch control signal SEN1 and a second switch control signal SEN2 based on the control operation. The processor 330 then sends... Figure 14A The control terminal g of the second switching circuit 35 shown outputs the aforementioned second switching control signal SEN2, so that the second switching circuit 35 is in the conducting state. At this time, the second switching circuit 35 can electrically connect the first boost circuit 31 and at least one stage of switched capacitor DC-DC converter 33, which is electrically connected between the second terminal b of the second switching circuit 35 and the first AC-DC conversion circuit 311.

[0151] At this time, the second electronic device 20, which is the electronic device to be charged, is located at the position of the first coil 321 in the first electronic device 10. The first electronic device 10 can reverse charge the second electronic device 20; therefore, the first electronic device 10 cannot perform the aforementioned forward charging via wireless charging. Therefore, the processor 330 can charge the second electronic device 20 as described above. Figure 14A The control terminal g of the first switch circuit 34 shown outputs the first switch control signal SEN1 to control the first switch circuit 34 to open.

[0152] The above description illustrates an example of a user directly triggering the reverse charging control button 52 to perform the aforementioned control operation. Alternatively, in some other embodiments of this application, before the processor 330 receives the user's control operation, the processor 330 may send a detection signal. This detection signal is used to connect the first electronic device 10 and the electronic device to be charged (e.g., the second electronic device 20). For example, the detection signal can be transmitted via Bluetooth. Next, if the first electronic device 10 and the electronic device to be charged successfully connect wirelessly, the processor 330 may output as follows: Figure 14D The instruction request information in the information prompt box 53 shown is used to instruct the user to perform a control operation. At this time, the user can trigger the "Y" button in the information prompt box 53 to perform the above control operation. After the processor 330 receives the user's control operation, it generates the first switch control signal SEN1 and the second switch control signal SEN2 as described above.

[0153] Furthermore, in some embodiments of this application, when the USB interface 50 is not electrically connected to a charging power source, such as an adapter, the processor 330 in the first electronic device 10 can control, for example... Figure 14A The fifth switch circuit 36 ​​shown is in the open state. At this time, the first electronic device 10 only needs to follow the... Figure 14AThe arrow indicates reverse charging of the second electronic device 20. Alternatively, in some other embodiments of this application, when the USB interface 50 is as shown... Figure 14B When electrically connected to the charging power supply 40, the processor 330 in the first electronic device 10 can control the fifth switching circuit 36 ​​to be in the conducting state. At this time, while the charging power supply 40 can forward charge the first battery 100 in the first electronic device 10, the first electronic device 10 can also... Figure 14A The arrow shown indicates that the second electronic device 20 is being reverse-charged.

[0154] The following combination Figure 15 The structures of the first switching circuit 34, the second switching circuit 35, and the fifth switching circuit 36 ​​described above are illustrated with examples. The first switching circuit 34 may include a first switching transistor M1, a second switching transistor M2, a third switching transistor M3, a first resistor R1, and a second resistor R2. The first terminal of each switching transistor can be the source, and the second terminal can be the drain. Alternatively, the first terminal can be the drain, and the second terminal can be the source.

[0155] The first terminal (c) of the first switching transistor M1 serves as the first terminal of the first switching circuit 34 and is electrically connected to the input terminal of the first voltage conversion circuit 301. The second terminal (d) of the first switching transistor M1 is electrically connected to the first terminal (c) of the second switching transistor M2. The second terminal (d) of the second switching transistor M2 serves as the second terminal of the first switching circuit 34 and is electrically connected between the second switching circuit 35 and the switched capacitor DC-DC converter 33.

[0156] Furthermore, the first terminal of the first resistor R1 is electrically connected to the second terminal d of the first switching transistor M1 and the first terminal cc of the second switching transistor M2. The second terminal of the first resistor R1 is electrically connected to the gate g of the first switching transistor M1 and the gate g of the second switching transistor M2. The first terminal c of the second resistor R2 is electrically connected to the second terminal of the second resistor R2. The first terminal c of the third switching transistor M3 is electrically connected to the second terminal of the second resistor R2, and the second terminal d of the third switching transistor M3 is grounded. The gate g of the third switching transistor M3 serves as the control terminal of the first switching circuit 34 and is electrically connected to the processor 330 to receive the first switching control signal SEN1 issued by the processor 330.

[0157] In this configuration, when the processor 330 controls the third switch M3 to turn on via the first switch control signal SEN1, both the first switch M1 and the second switch M2 are turned on, and the entire first switch circuit 34 is in a conducting state. The first resistor R1 and the second resistor R2, through voltage division, ensure that the voltage across the gate and source (or drain) of the first and second switch transistors M1 and M2 is within a reasonable range, thus preventing damage to the switch transistors while they are turned on. Furthermore, the parasitic diodes inside the first and second switch transistors M1 and M2 are reverse-biased. When the processor 330 controls the third switch M3 to turn off via the first switch control signal SEN1, both the first and second switch transistors M1 and M2 are in a cut-off state, and the entire first switch circuit 34 is in a disconnected state.

[0158] Furthermore, the aforementioned second switching circuit 35, as shown above... Figure 15 The circuit may include a fourth switch M4, a fifth switch M5, a sixth switch M6, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first terminal (c) of the fourth switch M4 serves as the first terminal of the second switching circuit 35 and is electrically connected to the first boost circuit 31. The second terminal (d) of the fourth switch M4 serves as the second terminal of the second switching circuit 35 and is electrically connected to the switched capacitor DC-DC converter 33. The first terminal (c) of the fifth switch M5 is electrically connected to the first terminal (c) of the fourth switch M4, and the second terminal (d) of the fifth switch M5 is electrically connected to the second terminal (d) of the fourth switch M4.

[0159] Furthermore, the first terminal of the third resistor R3 is electrically connected to the gate g of the fourth switch M4, and the second terminal is electrically connected to the second electrode d of the fourth switch M4. The first terminal of the fourth resistor R4 is electrically connected to the gate g of both the fourth switch M4 and the gate g of the fifth switch M5, and the second terminal is electrically connected to the second electrode d of the fifth switch M5. The first electrode of the fifth resistor R5 is electrically connected to the gate g of the fifth switch M5. The first electrode c of the sixth switch M6 is electrically connected to the second terminal of the fifth resistor R5, the second electrode d of the sixth switch M6 is grounded, and the gate g of the sixth switch M6 serves as the control terminal of the second switching circuit 35, which is electrically connected to the processor 330 to receive the second switch control signal SEN2 output by the processor 330.

[0160] In this scenario, when the processor 330 controls the sixth switch M6 to turn on via the second switch control signal SEN2, both the fourth switch M4 and the fifth switch M5 are also turned on, and the entire second switch circuit 35 is in a conducting state. The fourth switch M4 and the fifth switch M5 are connected in parallel. When the first boost circuit 31 outputs an electrical signal to the switched capacitor DC-DC converter 33 through the second switch circuit 35, it can effectively reduce the on-resistance (Rdson) of the second switch circuit 35, thereby improving signal transmission efficiency. Furthermore, the series-connected third resistor R3 and fifth resistor R5, through voltage division, ensure that the voltage across the gate and source (or drain) of the fourth switch M4 is within a reasonable range, thus preventing damage to the switch while it is conducting. Similarly, the series-connected fourth resistor R4 and fifth resistor R5, through voltage division, ensure that the voltage across the gate and source (or drain) of the fifth switch M5 is within a reasonable range. Furthermore, when the processor 330 controls the sixth switch transistor M6 to turn off via the second switch control signal SEN2, the fourth switch transistor M4 and the fifth switch transistor M5 are both in the off state, and the entire second switch circuit 35 is in the open state.

[0161] like Figure 15 As shown, the fifth switching circuit 36 ​​may include two switching transistors M. The parasitic diodes inside the two switching transistors M can be reversed. When the processor 330 controls the fifth switching circuit 36 ​​to be turned off through the fifth switch control signal SEN5, both switching transistors M in the fifth switching circuit 36 ​​are in the off state, and the entire fifth switching circuit 36 ​​is in the open state.

[0162] Furthermore, the fifth switching circuit 36 ​​may include a control circuit Con. This control circuit Con not only provides logic control signals to the two switching transistors in the fifth switching circuit 36, but also detects the voltage and current on the fifth switching circuit 36. When the USB interface is connected to a charging power source to charge the first electronic device 10, if the voltage and current on the fifth switching circuit 36 ​​are too high, the control circuit Con can send a command to the processor 330, causing the processor 330 to control the fifth switching circuit 36 ​​to turn off via the aforementioned fifth switching control signal SEN5, thereby achieving overcurrent protection (OCP) and overvoltage protection (OVP).

[0163] S104, Perform low-power charging.

[0164] Specifically, the first boost circuit 31 is controlled to boost the first battery voltage Vbat, and at least one switched capacitor DC-DC converter 33 is controlled to output the voltage output by the first boost circuit 31.

[0165] In order to control the power output of the first boost circuit 31, such as Figure 16 As shown, the first boost circuit can be equipped with a feedback terminal FB, and the second voltage conversion circuit also includes, for example, Figure 16 The diagram shows a pull-up resistor Ru, a pull-down resistor Rd, and a regulating resistor Rc. The first end of the pull-up resistor Ru is electrically connected to the output terminal of the first boost circuit 31, and the second end is electrically connected to the feedback terminal FB of the first boost circuit 31. The first end of the pull-down resistor Rd is electrically connected to the feedback terminal FB of the first boost circuit, and the second end is grounded. The first end of the regulating resistor Rc is electrically connected to the feedback terminal FB of the first boost circuit 31, and the second end is electrically connected to the general purpose input / output (GPIO) interface of the processor 330.

[0166] Based on this, when the user activates the second switch circuit 35 via the aforementioned reverse charging control button, causing the first electronic device 10 to begin reverse charging the second electronic device 20, the first boost circuit 31 can output a fixed low power (e.g., 5W) under the control of the processor 330, thereby enabling the first electronic device 10 to perform low-power slow charging on the second electronic device 20. For example, the first boost circuit 31 can boost the first battery voltage Vbat, for example, 3.7V, to 5V.

[0167] To control the output power of the first boost circuit 31 to be low (e.g., 5W), the processor 330 can leave the second end of the regulating resistor Rc floating. In this case, the regulating resistor Rc will not affect the voltage Vfb at the feedback terminal FB in the first boost circuit. The voltage Vfb at the feedback terminal FB and the voltage Vo1 at the output terminal of the first boost circuit 31 satisfy the following formula (1). At this time, by setting the values ​​of the pull-up resistor Ru and the pull-down resistor Rd, the voltage Vo1 at the output terminal of the first boost circuit 31 can be made 5V, resulting in an output power of approximately 5W for the first boost circuit 31. This allows the first electronic device 10 to perform low-power slow charging of the second electronic device 20.

[0168]

[0169] Based on this, taking the current on the first coil 321 as 1A as an example, in order for the first electronic device 10 to output 5W of charging power to the second electronic device 20, the switched capacitor DC-DC converter 33 can operate in the above-mentioned bypass mode, so that it can be used as a wire to transmit the voltage output by the first boost circuit 31, for example 5V, to the first AC-DC conversion circuit 311.

[0170] In some embodiments of this application, the structure of the switched capacitor DC-DC converter 33 can be as follows: Figure 17A As shown, the circuit includes a seventh switch M7, an eighth switch M8, a ninth switch M9, a tenth switch M10, and a first capacitor C1. The first terminal (c) of the seventh switch M7 serves as the input terminal (I / O1) of the switched-capacitor DC-DC converter 33 and is electrically connected to one end of the second switching circuit 35. The first terminal (c) of the eighth switch M8 is electrically connected to the second terminal (d) of the seventh switch M7, and the second terminal (d) of the eighth switch M8 serves as the output terminal (I / O2) of the switched-capacitor DC-DC converter 33 and is electrically connected to the first AC-DC conversion circuit. The first terminal of the first capacitor C1 is electrically connected to the second terminal (d) of the seventh switch M7. The first terminal (c) of the ninth switch M9 is electrically connected to the second terminal of the first capacitor C1, and the second terminal (d) of the ninth switch M9 is grounded. The first terminal (c) of the tenth switch M10 is electrically connected to the first terminal of the seventh switch M7, and the second terminal of the tenth switch M10 is electrically connected to the second terminal of the first capacitor C1.

[0171] In this case, when all switched-capacitor DC-DC converters 33 are operating in the aforementioned bypass mode, it can be as follows: Figure 17B As shown, the seventh switch M7 and the eighth switch M8 are turned on, while the ninth switch M9 and the tenth switch M10 are turned off. At this time, the switched capacitor DC-DC converter 33 can act as a wire, electrically connecting the second switching circuit 35 to the first AC-DC conversion circuit 311, so that the voltage output by the first boost circuit 31, for example, 5V, can be transmitted to the first AC-DC conversion circuit 311 through the second switching circuit 35 and the switched capacitor DC-DC converter 33.

[0172] In summary, when the first electronic device 10 begins to reverse charge the second electronic device 20, only the first boost circuit 31 in the second voltage conversion circuit 302 of the first electronic device 10 operates in boost mode. At this time, after executing the above S107, the first electronic device 10 defaults to charging the second electronic device 20 with low power (e.g., 5W).

[0173] S105, Request to increase receiving power.

[0174] When the second electronic device 20 located at the first coil 321 is a mobile phone or tablet requiring high power (e.g., 12W), the second electronic device 20 can send a wireless charging standard (Qi) protocol to the processor 330 of the first electronic device 10 via Bluetooth or a carrier signal. This Qi protocol may include fields matching a basic device identifier and fields matching a power boost request. The field matching the power boost request can be defined in the extended identification data packet of the Qi protocol. Thus, when the first electronic device 10 receives the Qi protocol sent by the second electronic device 20, it can identify the type of the second electronic device 20 through the field matching the basic device identifier and obtain the power boost request through the field matching the power boost request. When the power boost request is received, step S106 can be executed. When the power boost request is not received, step S104 is executed.

[0175] S106, Perform high-power charging.

[0176] Specifically, the first boost circuit 31 is controlled to boost the first battery voltage Vbat, and at least one switched capacitor DC-DC converter 33 is controlled to boost the voltage output by the first boost circuit 31.

[0177] When the first electronic device 10 receives the Qi protocol sent by the second electronic device 20, the first electronic device 10 needs to charge the second electronic device 20 with high power to improve the charging rate. In this case, in some embodiments of this application, when the processor 330 executes the above-described S105, the second terminal of the regulating resistor Rc can be grounded. At this time, the regulating resistor Rc and the pull-down resistor Rd are connected in parallel, and the total resistance value after parallel connection will decrease, thereby increasing the voltage Vo1 at the output terminal of the first boost circuit 31. At this time, by setting the resistance values ​​of the pull-up resistor Ru, the pull-down resistor Rd, and the regulating resistor Rc, the voltage Vo1 at the output terminal of the first boost circuit 31 can be increased to a fixed voltage value, such as 6V, so that the first boost circuit 31 operates at the peak position of voltage conversion efficiency. Taking the current on the first coil 321 as 1A as an example, the output power of the first boost circuit 31 increases to 6W.

[0178] Alternatively, in some other embodiments of this application, during the execution of S105 described above, the processor 330 may provide a pulse width modulation (PWM) signal to the second terminal of the control resistor Rc. In this case, the duty cycle D of the PWM signal can be changed as needed, causing a change in the voltage Vfb at the feedback terminal FB in the first boost circuit, thereby changing the voltage Vo1 at the output terminal of the first boost circuit 31. This allows the first boost circuit 31 to operate at its peak voltage conversion efficiency, for example, outputting 6W of power. At this time, the first boost circuit 31 operating at its peak voltage conversion efficiency can achieve higher voltage conversion efficiency.

[0179] In this case, the voltage Vo1 at the output of the first boost circuit 31, the voltage Vfb at the feedback terminal FB, and the voltage Vc at the second terminal of the regulating resistor Rc satisfy the following formula (2) with respect to the pull-up resistor Ru, the pull-down resistor Rd, and the regulating resistor Rc. Wherein, V GPIO This is the reference voltage for the aforementioned PWM signal.

[0180]

[0181] Based on this, in order for the first electronic device 10 to output 12W of charging power to the second electronic device 20, the switched-capacitor DC-DC converter 33 operates in boost mode. Taking a current of 1A on the first coil 321 as an example, the boost ratio of the switched-capacitor DC-DC converter 33 can be 2. At this time, the ratio of the input voltage to the output voltage of the switched-capacitor DC-DC converter 33 is 1:2. In this way, the switched-capacitor DC-DC converter 33 operating in boost mode can boost the voltage of 6V output from the first boost circuit 31 to 12V before outputting it.

[0182] The following is Figure 17A Taking the structure of the switched-capacitor DC-DC converter 33 shown as an example, the process by which the switched-capacitor DC-DC converter 33 achieves an input voltage to output voltage ratio of 1:2 will be described. Specifically, when the switched-capacitor DC-DC converter 33 operates in boost mode, the gate g of the seventh switch M7 and the gate g of the ninth switch M9 in the switched-capacitor DC-DC converter 33 receive the same drive signal. Similarly, the gate g of the eighth switch M8 and the gate g of the tenth switch M10 receive the same drive signal.

[0183] Based on this, in the first boost stage of the switched capacitor DC-DC converter 33, such as Figure 18A As shown, the seventh switch M7 and the ninth switch M9 are in the on state, while the eighth switch M8 and the tenth switch M10 are in the off state. The input voltage Vin charges the first capacitor C1 and the input capacitor Cin in the direction of the arrow. Figure 18AThe equivalent circuit diagram is as follows Figure 18B As shown, the input capacitor Cin is connected in parallel with the first capacitor C1. In this case, the voltage Vin across the input capacitor Cin is the same as the voltage Vc1 across the first capacitor C1, that is, Vin = Vc1.

[0184] In the second boost stage of the switched capacitor DC-DC converter 33, such as Figure 19A As shown, the seventh switch M7 and the ninth switch M9 are in the off state, while the eighth switch M8 and the tenth switch M10 are in the on state. The first capacitor C1 and the input capacitor Cin discharge to the output terminal I / O2 of the switched capacitor DC-DC converter 33 in the direction of the arrow. Figure 19A The equivalent circuit diagram is as follows Figure 19B As shown, the input capacitor Cin is connected in series with the first capacitor C1, and then in parallel with the output capacitor Cout. In this case, the voltage Vout across the output capacitor Cout is the sum of the voltage Vin across the input capacitor Cin and the voltage Vc1 across the first capacitor C1, i.e., Vout = Vin + Vc1. Since Vin = Vc1, Vout = 2Vin. This allows the switched capacitor DC-DC converter 33 to double the input voltage before outputting it, achieving the goal of boosting the 6V output from the first boost circuit 31 to 12V before output.

[0185] The above description illustrates the structure of a switched-capacitor DC-DC converter 33, using an example of a switched-capacitor DC-DC converter 33 with four switching transistors (M7, M8, M9, and M10) and one capacitor (C1). In other embodiments of this application, such as... Figure 20A As shown, the switched capacitor DC-DC converter 33 may include a seventh switch M7, an eighth switch M8, a ninth switch M9, a tenth switch M10, an eleventh switch M11, a twelfth switch M12, a thirteenth switch M13, a fourteenth switch M10, a first capacitor C1, and a second capacitor C2.

[0186] In this circuit, the first terminal (c) of the seventh switch transistor M7 serves as the input terminal (I / O1) of the switched-capacitor DC-DC converter 33 and is electrically connected to one end of the second switching circuit 35. The first terminal (c) of the eighth switch transistor M8 is electrically connected to the second terminal (d) of the seventh switch transistor M7, and the second terminal (d) of the eighth switch transistor M8 serves as the output terminal (I / O2) of the switched-capacitor DC-DC converter 33 and is electrically connected to the first AC conversion circuit 311. The first terminal of the first capacitor C1 is electrically connected to the second terminal (d) of the seventh switch transistor M7. The first terminal (c) of the ninth switch transistor M9 is electrically connected to the second terminal of the first capacitor C1, and the second terminal (d) of the ninth switch transistor M9 is electrically connected to the second terminal (d) of the eighth switch transistor M8. The first terminal (c) of the tenth switch transistor M10 is electrically connected to the first terminal (c) of the seventh switch transistor M7, and the second terminal (d) of the tenth switch transistor M10 is electrically connected to the second terminal of the first capacitor C1.

[0187] Furthermore, the second terminal (d) of the eleventh switch M11 is electrically connected to the first terminal (c) of the seventh switch M7. The first terminal (c) of the twelfth switch M12 is grounded, and the second terminal (d) of the twelfth switch M12 is electrically connected to the first terminal (c) of the eleventh switch M11. The first terminal of the second capacitor C2 is electrically connected to the first terminal (c) of the eleventh switch M11. The first terminal (c) of the thirteenth switch M13 is grounded, and the second terminal (d) of the thirteenth switch M13 is electrically connected to the second terminal of the second capacitor C2. The first terminal (c) of the fourteenth switch M14 is electrically connected to the second terminal of the second capacitor C2, and the second terminal (d) of the fourteenth switch M14 is electrically connected to the second terminal (d) of the eleventh switch M1.

[0188] Figure 20A The switched-capacitor DC-DC converter 33 shown can also achieve an input voltage to output voltage ratio of 1:2 when operating in boost mode. Specifically, when the switched-capacitor DC-DC converter 33 operates in boost mode, the gates g of the seventh switch M7, the ninth switch M9, the fourteenth switch M14, and the twelfth switch M12 in the switched-capacitor DC-DC converter 33 receive the same drive signal. Similarly, the gates g of the eighth switch M8, the tenth switch M10, the eleventh switch M11, and the thirteenth switch M13 also receive the same drive signal.

[0189] Based on this, in the first boost stage of the switched capacitor DC-DC converter 33, such as Figure 20BAs shown, the seventh switch M7, the ninth switch M9, the fourteenth switch M14, and the twelfth switch M12 are turned on, while the eighth switch M8, the tenth switch M10, the eleventh switch M11, and the thirteenth switch M13 are turned off. Similarly, the input capacitor Cin is connected in parallel with the first capacitor C1 and the second capacitor C2. In this case, the voltage Vin across the input capacitor Cin is the same as the voltage Vc1 across the first capacitor C1 and the voltage Vc2 across the second capacitor C2, i.e., Vin = Vc1 = Vc2.

[0190] In the second boost stage of the switched capacitor DC-DC converter 33, such as Figure 20C As shown, the seventh switch M7, the ninth switch M9, the fourteenth switch M14, and the twelfth switch M12 are off, while the eighth switch M8, the tenth switch M10, the eleventh switch M11, and the thirteenth switch M13 are on. Similarly, the input capacitor Cin is connected in series with the first capacitor C1 and then in parallel with the output capacitor Cout. Furthermore, the second capacitor C2 is connected in series with the input capacitor Cin and then in parallel with the output capacitor Cout. In this case, the voltage Vout across the output capacitor Cout is the sum of the voltage Vin across the input capacitor Cin and the voltage Vc1 across the first capacitor C1. Also, the voltage Vout across the output capacitor Cout is the sum of the voltage Vin across the input capacitor Cin and the voltage Vc2 across the second capacitor C2, i.e., Vout = Vin + Vc1 = Vin + Vc2. Since Vin = Vc1 = Vc2, therefore, Vout = 2Vin. In this way, the switched capacitor DC-DC converter 33 can double the input voltage before outputting it, thus achieving the purpose of boosting the 6V output voltage of the first boost circuit 31 to 12V before outputting it.

[0191] The above is an example of a switched capacitor DC-DC converter 33. Figure 20A The structure of the switched-capacitor DC-DC converter 33 is illustrated using an example of a converter with eight switching transistors (M7, M8, M9, M10, M11, M12, M13, and M14) and one capacitor (C1 and C2). (Compared to...) Figure 17A For the switched capacitor DC-DC converter 33 shown, the boost factor is 2, but because Figure 20A The use of a large number of switching transistors increases the current carrying capacity, which is beneficial for increasing the output current of the switched capacitor DC-DC converter 33.

[0192] Based on this, the switching transistor in the aforementioned switched-capacitor DC-DC converter 33 has a certain load driving capability, therefore, this switching transistor requires a relatively high voltage for driving. Therefore, as... Figure 20AAs shown, the switched-capacitor DC-DC converter 33 may further include a logic control circuit 42 and multiple drivers 43, with each switch's gate g connected to a driver 43. The logic control circuit 42 is electrically connected to the processor 330 and provides logic control signals to the gates of each switch, indicating the on or off state of the switch. Furthermore, the drivers 43 convert the logic control signals output by the logic control circuit 42 into drive signals with driving capability to control the on and off states of the switches.

[0193] Furthermore, in order for the aforementioned switched-capacitor DC-DC converter 33 to start normally, the wireless charging circuit in the first electronic device may also include, for example, Figure 21 The third diode D3 is shown. The anode of the third diode D3 is electrically connected to the input terminal of the switched-capacitor DC-DC converter 33, and the cathode of the third diode D3 is electrically connected to the output terminal of the switched-capacitor DC-DC converter 33. Thus, when the first boost circuit 31 supplies voltage to the input terminal of the switched-capacitor DC-DC converter 33 through the second switching circuit 35, the output terminal of the switched-capacitor DC-DC converter 33 also has voltage due to the freewheeling effect of the third diode D3. Furthermore, when the voltage at the output terminal of the third diode D3 is greater than the voltage at the input terminal, pre-starting of the switched-capacitor DC-DC converter 33 can be achieved.

[0194] The above description uses the example of the second voltage conversion circuit 302 of the first electronic device 10 having a single-stage switched-capacitor DC-DC converter 33, where the input voltage to output voltage ratio of the switched-capacitor DC-DC converter 33 is 1:2, thereby boosting the voltage output of the first boost circuit 31 from 6V to 12V. In other embodiments of this application, when the charging power of the second electronic device 20, which is the electronic device to be charged, increases to 24W, the first electronic device 10 may include two stages such as... Figure 22A The switched capacitor DC-DC converters shown are a first-stage switched capacitor DC-DC converter 33a and a second-stage switched capacitor DC-DC converter 33b, respectively. The output terminal of the first-stage switched capacitor DC-DC converter 33a is electrically connected to the input terminal of the second-stage switched capacitor DC-DC converter 33b.

[0195] In either the first-stage switched-capacitor DC-DC converter 33a or the second-stage switched-capacitor DC-DC converter 33b, the ratio of the input voltage to the output voltage is 1:2. When the structures of the first-stage switched-capacitor DC-DC converter 33a and the second-stage switched-capacitor DC-DC converter 33b can be as follows... Figure 20A As shown, each has eight switching transistors (M7, M8, M9, M10, M11, M12, M13 and M14) and one capacitor (C1 and C2).

[0196] Based on this, since the output power of the first electronic device 10 is increased to 24W, in order to improve the driving capability of the second voltage conversion circuit 302, the second voltage conversion circuit 302 further includes, for example, Figure 22B The third boost circuit 51 is shown. This third boost circuit 51 is connected in parallel with the first boost circuit 31, and its structure and boost factor are the same as the first boost circuit 31. In this way, by setting the third boost circuit 51 and the first boost circuit 31 in parallel in the second voltage conversion circuit 302, the number of cascaded first-stage switched-capacitor DC-DC converters 33a and 33b can be matched, thereby facilitating the increase of the output power of the first electronic device 10 from 12W to 24W.

[0197] In addition, the wireless charging circuit of the first electronic device may also include, for example Figure 22A The first diode D1 and the second diode D2 are shown. The anode of the first diode D1 is electrically connected to the output terminal of the first boost circuit 31, and the cathode of the first diode D1 can be electrically connected to the first AC-DC conversion circuit 311 through the second switching circuit 35, the first-stage switched-capacitor DC-DC converter 33a, and the second-stage switched-capacitor DC-DC converter 33b. The anode of the second diode D2 is electrically connected to the output terminal of the third boost circuit 51, and the cathode of the second diode D2 can be electrically connected to the first AC-DC conversion circuit 311 through the second switching circuit 35, the first-stage switched-capacitor DC-DC converter 33a, and the second-stage switched-capacitor DC-DC converter 33b. Through the unidirectional conduction of the first diode D1 and the second diode D2, signal crosstalk between the parallel-connected first boost circuit 31 and the third boost circuit 51 can be avoided.

[0198] In this way, the first-stage switched-capacitor DC-DC converter 33a can boost the 6V output from the parallel first boost circuit 31 and third boost circuit 51 to 12V and then transmit it to the second-stage switched-capacitor DC-DC converter 33b. The second-stage switched-capacitor DC-DC converter 33b can boost the 12V output from the first-stage switched-capacitor DC-DC converter 33a to 24V and then output it to the first AC-DC conversion circuit 311. Taking the current on the first coil 321 as an example, the first electronic device 10 can provide 20W of output power to the second electronic device 20, which is the electronic device to be charged. The boosting process of the first-stage switched-capacitor DC-DC converter 33a and the second-stage switched-capacitor DC-DC converter 33b is the same as described above, and will not be repeated here.

[0199] S107, the first coil 321 emits an alternating magnetic field.

[0200] Specifically, after executing S104 or S106, S107 can be executed to control the first AC-DC conversion circuit 311 to convert the voltage output by at least one stage switched capacitor DC converter 33 into AC voltage, so as to excite the first coil 321 to emit an alternating magnetic field.

[0201] In some embodiments of this application, the first AC-DC conversion circuit 311 described above may include, for example: Figure 21 The multiple switching transistors shown Figure 21 (Taking four switching transistors as an example) and an inverter and control circuit Con used to control the switching transistors to turn on and off. In this way, the four switching transistors can form a full-bridge circuit, capable of converting the DC voltage output from the switched-capacitor DC-DC converter 33 into AC voltage. When the first coil 321 receives this AC voltage, it can emit an alternating magnetic field. The electronic device to be charged, located at the position of the first coil 321, such as the second electronic device 20 mentioned above (e.g., ... Figure 22A The third coil 323 in the diagram generates an AC voltage. The third AC-DC conversion circuit 313 converts the AC voltage induced by the third coil 323 after receiving the AC magnetic field into a DC voltage and transmits the DC voltage to the second battery 200 to charge the second battery 200, thereby realizing the wireless reverse charging process of the first electronic device 10 to the second electronic device 20.

[0202] S108. Determine whether the temperature of the first battery 100 is greater than the first temperature threshold Tth1 (e.g., Tth1 = 37°C).

[0203] After S107, the first electronic device 10 can charge the second electronic device 20 at high power, such as 12W (or 24W). Therefore, at any time after S107, S108 and S109 can be executed to perform the first over-temporal protection (OTP) on the first electronic device 10.

[0204] Specifically, the wireless charging circuit of the aforementioned first electronic device may further include, for example: Figure 23 The first thermistor 61 is shown. The first thermistor 61 is electrically connected to the processor 330 and can be positioned near the first battery 100. This first thermistor 61 is used to sense the temperature of the first battery 100. In this way, the above-described S108 can be executed based on the result sensed by the first thermistor 61.

[0205] Furthermore, the wireless charging circuit of the aforementioned first electronic device may also include, for example: Figure 23The second thermistor 62 is shown. The second thermistor 62 can be electrically connected to the processor 300 and is located near the first boost circuit 31 and the processor 330. The second thermistor 62 is used to sense the temperature of the first boost circuit 31 and the processor 330.

[0206] It should be noted that, Figure 23 For ease of explanation, the distance between the processor 330 and the first boost circuit 31 is set relatively far. In actual application scenarios, the processor 330 can be placed near the first boost circuit 31, so that the second thermistor 62 is close to both the first boost circuit 31 and the processor 330, thereby enabling it to sense the temperature of the first boost circuit 31 and the processor 330.

[0207] In this case, the processor 330 can control the second terminal of the regulating resistor Rc to be left floating or grounded, or provide a PWM signal to the second terminal of the regulating resistor Rc, based on the sensing results of the first thermistor 61 and the second thermistor 62, so as to control the output power of the first boost circuit 31.

[0208] During the execution of S108, when the temperature of the first battery 100 is greater than the first temperature threshold Tth1, the following S109 is executed. Furthermore, when the temperature of the first battery 100 is less than the first temperature threshold Tth1, the above-mentioned S106 is executed, meaning that the first boost circuit 31 and the switched capacitor DC-DC converter 33 in the second voltage conversion circuit 302 both operate in boost mode, and the output power of the first electronic device 10 can maintain its original high power, for example, 12W (or 24W) to charge the second electronic device 20.

[0209] S109. Control at least one stage switched capacitor DC-DC converter 33 to output the voltage output by the first boost circuit 31.

[0210] At this time, the switched-capacitor DC-DC converter 33 operates in the bypass mode described above, acting as a wire to transmit the voltage (e.g., 5V or 6V) output by the first boost circuit 31 to the first AC-DC conversion circuit. In this case, only the first boost circuit 31 in the second voltage conversion circuit 302 operates in boost mode, and the power output of the entire first electronic device 10 is reduced from a high power, such as 12W (or 24W), to a low power, such as 5W or 6W. Thus, when the temperature of the first battery 100 exceeds the first temperature threshold Tth1, the output power of the first electronic device 10 can be reduced to prevent severe overheating of the first battery 100. After executing S109, S110 and S111 can be executed to perform a second over-temperature protection for the first electronic device 10.

[0211] S110. Determine whether the temperature of the first battery 100 is greater than the second temperature threshold Tth2 (e.g., Tth2 = 50°C).

[0212] After executing S109 and reducing the output power of the first electronic device 10, the temperature of the first battery 100 needs to be detected again. During S110, the temperature of the first battery 100 needs to be compared with a second temperature threshold Tth2. This second temperature threshold Tth2 is greater than the first temperature threshold Tth1 (e.g., Tth2 = 37°C). If the temperature of the first battery 100 is greater than the second temperature threshold Tth2, S111 needs to be executed to shut down the first boost circuit 31, thereby stopping the first electronic device 10 from reverse charging the second electronic device 20. When the temperature of the first battery 100 is less than the second temperature threshold Tth2, S112 can be executed.

[0213] S111, Turn off the first boost circuit 31.

[0214] In addition, after the first AC-DC conversion circuit 311 converts the DC voltage output by the second voltage conversion circuit 302 into AC voltage to charge the second electronic device 20, the above method may also include the following S112.

[0215] S112. Determine whether the charge of the first battery 100 is less than the minimum charge threshold Qth.

[0216] During the charging process of the first electronic device 10 to the second electronic device 20, the above-described S112 can be executed to determine the power level of the first battery 100. When the power level of the first battery 100 is less than the minimum power threshold Qth, the above-described S111 can be executed to shut down the first boost circuit 31, thereby causing the first electronic device 10 to stop reverse charging the second electronic device 20, achieving the purpose of undervoltage lockout (UVLO). When the power level of the first battery 100 is greater than the minimum power threshold Qth, the above-described S106 can be executed.

[0217] The above description illustrates the process of the first electronic device 10 reverse-charging the second electronic device 20. As explained above, the second electronic device 20 can be an electronic device capable of low-power charging, such as a smartwatch, wireless headphones, or a stylus, or an electronic device requiring high-power charging, such as a mobile phone or tablet. In other embodiments of this application, in addition to the first electronic device 10 reverse-charging the second electronic device 20, the wireless charging system 01 may further include, for example... Figure 24 The third electronic device 31 shown. The first electronic device 10 can also handle, for example, Figure 24The third electronic device 31 shown performs reverse charging. This third electronic device 31 can be an electronic device that performs low-power charging, for example, such as... Figure 2 The stylus shown in (e) is shown in the image.

[0218] In this case, the wireless charging circuit in the first electronic device may further include, for example: Figure 24 The diagram shows a second boost circuit 32, a second AC-DC converter 312, and a second coil 322. The second boost circuit 32 can be connected to the output of the first voltage conversion circuit 301. The second boost circuit 32 can boost the first battery voltage Vbat output from the first voltage conversion circuit 301 and output it to the second AC-DC converter. The boost factor of the second boost circuit 32 is less than or equal to the boost factor of the first boost circuit 31. For example, the output voltage of the second boost circuit 32 can be 5V. The second AC-DC converter 312 is electrically connected to the second boost circuit 32. The second AC-DC converter 312 can convert the DC voltage output from the second boost circuit 32 into an AC voltage. The second coil 322 is electrically connected to the second AC-DC converter 312 and is used to emit an alternating magnetic field. Taking a current of 1A in the second coil 322 as an example, when the output voltage of the second boost circuit 32 is 5V, the first electronic device 10 can provide 5W of charging power to the third electronic device 31.

[0219] Based on this, the third electronic device 31 may include a third battery 300, a fourth coil 324, and a fourth AC-DC conversion circuit 314. The fourth coil 324 receives the alternating magnetic field emitted by the second coil 322 and induces an AC voltage. The fourth AC-DC conversion circuit 314 is electrically connected to the fourth coil 324 and the third battery 300. This fourth AC-DC conversion circuit 314 converts the AC voltage induced by the fourth coil 324 after receiving the AC magnetic field into a DC voltage to charge the third battery 300. In this way, a wireless reverse charging process can be realized between the first electronic device 10 and the third electronic device 31.

[0220] In some embodiments of this application, when the first electronic device 10 reverse-charges the stylus, which is a third electronic device 31, the stylus can perform the following functions: Figure 25 As shown, the stylus is attached to the edge of the first electronic device 10. At this time, the second coil 322 in the first electronic device 10 can be disposed at the edge of the third electronic device 31, so that when the stylus is attached to the edge of the first electronic device 10, the fourth coil 324 in the stylus can correspond to the position of the second coil 322 in the first electronic device 10.

[0221] The following example illustrates a method for the first electronic device 10 to reverse charge a stylus that serves as a third electronic device 31. This method may include, for example... Figure 26 S201 to S203 are shown.

[0222] S201, Receive in-situ command.

[0223] The in-situ instruction is used to indicate that the location of the second coil 322 of the first electronic device 10 has an electronic device to be charged, such as the third electronic device 31 described above.

[0224] Specifically, in the first electronic device 10, a Hall detector (not shown in the figure) can be placed near the location of the second coil 322. The Hall detector is used to detect whether the third electronic device 31 is in place. When the third electronic device 31 is detected to be in place, an in-place instruction can be sent to the processor 330 in the first electronic device 10, so that the processor 330 can receive the above-mentioned in-place instruction.

[0225] In this case, when the processor 330 of the first electronic device 10 controls as follows Figure 24 After the first voltage conversion circuit 301 shown outputs the first battery voltage Vbat provided by the first battery 100, it can execute the following S202.

[0226] S202. According to the in-situ instruction, control the second boost circuit 32 to boost the first battery voltage Vbat and output it to the second AC-DC conversion circuit 312.

[0227] Specifically, as described above, when the Hall detector detects that an electronic device to be charged, such as a third electronic device 31, is located at the position of the second coil 322, the Hall detector can send a presence command to the processor 330, so that the processor 330 can generate a fourth switch control signal SEN4 according to the presence command. Next, the processor 330 can send... Figure 28 The control terminal g of the fourth switching circuit 38 shown outputs the fourth switching control signal SEN4, controlling the fourth switching circuit SEN4 to conduct. This electrically connects the second boost circuit 32 and the second AC-DC converter circuit 312, thereby executing the above-described 202.

[0228] S203, the second AC-DC conversion circuit 312 converts the DC voltage output by the second boost circuit 32 into AC voltage.

[0229] Specifically, the processor 330 of the first electronic device 10 can execute step 203 as described above to excite the second coil 322 to emit an alternating magnetic field. In this way, the fourth coil 324 in the third electronic device 31 receives the alternating magnetic field emitted by the second coil 322 and induces an alternating voltage. The fourth AC-DC conversion circuit 314 converts the alternating voltage induced by the fourth coil 324 after receiving the alternating magnetic field into a direct current voltage to charge the third battery 300, thereby realizing the process of the first electronic device 10 reversibly charging the stylus of the third electronic device 31.

[0230] Based on this, the wireless charging circuit 30 may also include, for example: Figure 24 The third switch circuit 37 and the fourth switch circuit 38 are shown. The control terminal g of the third switch circuit 37 can be connected to, for example... Figure 27 The processor 330 shown is electrically connected. The control terminal g of the third switch circuit 37 is used to receive the third switch control signal SEN3. The first terminal a of the third switch circuit 37 is electrically connected to the USB interface 50, and the second terminal b of the third switch circuit 37 is electrically connected to the output terminal of the second boost circuit 32. The third switch circuit 37 is used to turn on or off according to the third switch control signal SEN3.

[0231] For example, such as Figure 27 As shown, the third switching circuit 37 may include two switching transistors M. The parasitic diodes inside the two switching transistors M can be reversed. When the processor 330 controls the third switching circuit 37 to turn off via the third switch control signal SEN3, both switching transistors M in the third switching circuit 37 are in the off state, and the entire third switching circuit 37 is in the open state. Furthermore, the third switching circuit 37 may include a control circuit Con. This control circuit Con can not only provide logic control signals to the two switching transistors in the third switching circuit 37, but also detect the voltage and current on the third switching circuit 37. When the voltage and current at the USB interface are too high, the control circuit Con can send a command to the processor 330, causing the processor 330 to control the third switching circuit 37 to turn off via the third switch control signal SEN3, thereby realizing OCP and OVP.

[0232] In addition, such as Figure 24 As shown, the control terminal g of the fourth switch circuit 38 can be electrically connected to the processor 330. The control terminal g of the fourth switch circuit 38 is used to receive the fourth switch control signal SEN4. The first terminal of the fourth switch circuit 38 is electrically connected to the output terminal of the second boost circuit 32, and the second terminal of the fourth switch circuit 38 is electrically connected to the second AC / DC converter circuit 312. The fourth switch circuit 38 is used to turn on or off according to the fourth switch control signal SEN4.

[0233] Based on this, in some embodiments of this application, such as Figure 28 As shown, when a second electronic device 20 to be charged is positioned at the location of the first coil 321 of the first electronic device 10, and a third electronic device 31 to be charged is positioned at the location of the second coil 322, the processor 330 can control as follows: Figure 28 The first switch circuit 34, the third switch circuit 37, and the fifth switch circuit 36 ​​shown are disconnected, and the second switch circuit 35 and the fourth switch circuit 38 are turned on. At this time, after the first voltage conversion circuit 301 outputs the first battery voltage Vbat1 provided by the first battery 100, the charging path composed of the first boost circuit 31, the switched capacitor DC-DC converter 33, the first AC-DC conversion circuit 311, and the first coil 321 can be constructed as described above. Figure 9 The control method shown performs reverse charging of the second electronic device 20 in the direction of the arrow.

[0234] Meanwhile, the charging path formed by the second AC-DC conversion circuit 312 and the second coil 322 can be adopted as follows: Figure 26 The control method shown performs reverse charging of the third electronic device 31 in the direction of the arrow.

[0235] Alternatively, in some other embodiments of this application, when the USB interface 50 is electrically connected to an external device (e.g., a mobile storage medium, a keyboard, etc.), and the first electronic device 10 is simultaneously charging the second electronic device 20 and the third electronic device 31, the control method of the processor 330 may further include generating a third switch control signal SEN3 based on the identification result of the external device type by the USB interface 50. For example, if the USB interface 50 is electrically connected to an external device, such as a keyboard, the USB interface 50 will determine the type of the external device. When it is determined that the external device needs the first battery 100 to supply power, the USB interface 50 will send a control command to the processor 330, so that the processor 330 generates the aforementioned third switch control signal SEN3 according to the control command.

[0236] Next, the processor 330 generates the aforementioned third switch control signal SEN3 according to the third control instruction, and outputs the third switch control signal SEN3 to the control terminal g of the third switch circuit 37, controlling the third switch circuit 37 to conduct and electrically connect the USB interface 50 to the second boost circuit 32. Next, the processor 330 controls the third switch circuit 37 as follows... Figure 29 The circuit is in the on state.

[0237] At this time, the second boost circuit 32 boosts the first battery voltage Vbat1 and transmits the boosted voltage to the external device via the third switching circuit 37 in the direction of the arrow, so as to power the external device, such as a mobile storage medium, keyboard, etc. When the external device is powered by the first electronic device 10, it can transmit data with the first electronic device 10, so that the USB interface 50 of the first electronic device 10 has the function of data exchange (on-the-go, OTG).

[0238] Alternatively, in some other embodiments of this application, when the USB interface 50 is electrically connected to an external device (e.g., a mobile storage medium, a keyboard, etc.), the processor 330 can also control the fourth switching circuit 38 as follows: Figure 30 The device is in a disconnected state. In this way, the first electronic device 10 supplies power to the second electronic device 20 and the aforementioned external device simultaneously, but no longer supplies power to the third electronic device 31, thereby reducing the power consumption of the first battery 100 in the first electronic device 10.

[0239] The above description uses the example of the first electronic device 10 reverse charging the second electronic device 20 and the third electronic device 31, or supplying power to an external device electrically connected via the USB interface 50. In other embodiments of this application, such as Figure 31 As shown, when a wireless charging power supply 41 is positioned at the location of the first coil 321 of the first electronic device 10, the processor 330 can control the first switching circuit 34 and the third switching circuit 37 to be turned on, and control the second switching circuit 35, the fourth switching circuit 38, and the fifth switching circuit 36 ​​to be turned off. In this case, the wireless charging power supply 41 can charge the first battery 100 in the first electronic device 10 via the first switching circuit 34 in the direction of the arrow. At the same time, after the first voltage conversion circuit 301 outputs the first battery voltage Vbat1 provided by the first battery 100, the second boost circuit 32 boosts the first battery voltage Vbat1 and transmits the boosted voltage to the external device via the third switching circuit 37 in the direction of the arrow to power the external device.

[0240] This application provides a computer-readable storage medium including computer instructions that, when executed on the processor 330 of the first electronic device 10, cause the processor 330 to perform any of the control methods described above.

[0241] Furthermore, this application provides a computer program product, including computer instructions, which, when executed on the processor 330 of the first electronic device 10, can cause the processor 330 to perform any of the aforementioned control methods.

[0242] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A wireless charging circuit, comprising: The wireless charging circuit comprises: a first voltage conversion circuit electrically connected with the first battery; the first voltage conversion circuit is configured to convert a power supply voltage into a first battery voltage of the first battery, and charge the first battery; the first voltage conversion circuit is further configured to output the first battery voltage provided by the first battery; a second voltage conversion circuit electrically connected with the first voltage conversion circuit, configured to step up the first battery voltage; the second voltage conversion circuit comprises a first step-up circuit and at least one stage of a switched capacitor direct current converter connected in series; a first alternating current-direct current conversion circuit electrically connected with the second voltage conversion circuit, configured to convert a direct current voltage output by the second voltage conversion circuit into an alternating current voltage; the wireless charging circuit further comprises a first switch circuit; a control end of the first switch circuit is configured to receive a first switch control signal; a first end of the first switch circuit is electrically connected with an input end of the first voltage conversion circuit; a second end of the first switch circuit is electrically connected with the first alternating current-direct current conversion circuit; the first switch circuit is configured to be turned on or turned off according to the first switch control signal; the second end of the first switch circuit is electrically connected between the first step-up circuit and the at least one stage of the switched capacitor direct current converter; the second end of the first switch circuit is indirectly electrically connected with the first alternating current-direct current conversion circuit through the at least one stage of the switched capacitor direct current converter; the first alternating current-direct current conversion circuit is further configured to convert the alternating current voltage into the direct current voltage.

2. The wireless charging circuit of claim 1, wherein, The wireless charging circuit further comprises: a second step-up circuit electrically connected with the first voltage conversion circuit, configured to output a stepped-up first battery voltage; wherein a step-up multiple of the second step-up circuit is less than or equal to a step-up multiple of the first step-up circuit; a second alternating current-direct current conversion circuit electrically connected with the second step-up circuit, configured to convert a direct current voltage output by the second step-up circuit into an alternating current voltage.

3. The wireless charging circuit of claim 1 or 2, wherein, The first step-up circuit has a feedback end; the second voltage conversion circuit further comprises: a pull-up resistor; a first end of the pull-up resistor is electrically connected with an output end of the first step-up circuit; a second end of the pull-up resistor is electrically connected with the feedback end of the first step-up circuit; a pull-down resistor; a first end of the pull-down resistor is electrically connected with the feedback end of the first step-up circuit; a second end of the pull-down resistor is grounded; a regulation resistor; a first end of the regulation resistor is electrically connected with the feedback end of the first step-up circuit; a second end of the regulation resistor is configured to be left floating, grounded, or receive a pulse width modulation signal.

4. The wireless charging circuit according to any one of claims 1-3, wherein: the first step-up circuit and the at least one stage of the switched capacitor direct current converter are electrically connected in sequence between the first voltage conversion circuit and the first alternating current-direct current conversion circuit.

5. The wireless charging circuit of claim 1, wherein, The first switch circuit comprises: a first switch tube; a first pole of the first switch tube serves as the first end of the first switch circuit. a second switch tube; a first electrode of the second switch tube is electrically connected with a second electrode of the first switch tube, and a second electrode of the second switch tube is used as a second end of the first switch circuit; a first resistor; a first end of the first resistor is electrically connected with the second electrode of the first switch tube and a first electrode of the second switch tube, and a second end of the first resistor is electrically connected with a gate electrode of the first switch tube and a gate electrode of the second switch tube; a second resistor; a first end of the second resistor is electrically connected with the second end of the first resistor; a third switch tube; a first electrode of the third switch tube is electrically connected with the second end of the second resistor, a second electrode of the third switch tube is grounded, and a gate electrode of the third switch tube is used as a control end of the first switch circuit.

6. The wireless charging circuit of any one of claims 1-5, wherein, The wireless charging circuit further comprises a second switch circuit; a control end of the second switch circuit is used for receiving a second switch control signal, a first end of the second switch circuit is electrically connected with the first boost circuit, and a second end of the second switch circuit is electrically connected with the at least one-stage switched-capacitor direct-current converter; and the second switch circuit is used for being turned on or turned off according to the second switch control signal.

7. The wireless charging circuit of claim 6, wherein, The second switch circuit comprises: a fourth switch tube; a first electrode of the fourth switch tube is used as a first end of the second switch circuit, and a second electrode of the fourth switch tube is used as a second end of the second switch circuit; a third resistor; a first end of the third resistor is electrically connected with a gate electrode of the fourth switch tube, and a second end of the third resistor is electrically connected with a second electrode of the fourth switch tube; a fifth switch tube; a first electrode of the fifth switch tube is electrically connected with a first electrode of the fourth switch tube, and a second electrode of the fifth switch tube is electrically connected with a second electrode of the fourth switch tube; a fourth resistor; a first end of the fourth resistor is electrically connected with the gate electrode of the fourth switch tube and a gate electrode of the fifth switch tube, and a second end of the fourth resistor is electrically connected with a second electrode of the fifth switch tube; a fifth resistor; a first electrode of the fifth resistor is electrically connected with the gate electrode of the fifth switch tube; a sixth switch tube; a first electrode of the sixth switch tube is electrically connected with a second end of the fifth resistor, a second electrode of the sixth switch tube is grounded, and a gate electrode of the sixth switch tube is used as a control end of the second switch circuit.

8. The wireless charging circuit according to claim 2, wherein the wireless charging circuit further comprises a third switch circuit; a control end of the third switch circuit is used for receiving a third switch control signal, a first end of the third switch circuit is electrically connected with a USB interface, and a second end of the third switch circuit is electrically connected with an output end of the second boost circuit; and the third switch circuit is used for being turned on or turned off according to the third switch control signal.

9. The wireless charging circuit according to claim 2 or 8, wherein The wireless charging circuit further comprises a fourth switch circuit; a control end of the fourth switch circuit is used for receiving a fourth switch control signal, a first end of the fourth switch circuit is electrically connected with an output end of the second voltage boosting circuit, and a second end of the fourth switch circuit is electrically connected with the second AC-DC conversion circuit; the fourth switch circuit is used for being turned on or turned off according to the fourth switch control signal.

10. The wireless charging circuit of any one of claims 1-7, wherein, The wireless charging circuit further comprises a fifth switch circuit; a control end of the fifth switch circuit is used for receiving a fifth switch control signal, a first end of the fifth switch circuit is electrically connected with a USB interface, and a second end of the fifth switch circuit is electrically connected with an input end of the first voltage conversion circuit; the fifth switch circuit is used for being turned on or turned off according to the fifth switch control signal.

11. The wireless charging circuit of any of claims 1-10, wherein, Any one of the at least one stage of the switched capacitor DC-DC converter comprises: a seventh switch tube; a first pole of the seventh switch tube is used as an input end of the switched capacitor DC-DC converter; an eighth switch tube; a first pole of the eighth switch tube is electrically connected with a second pole of the seventh switch tube, and a second pole of the eighth switch tube is used as an output end of the switched capacitor DC-DC converter; a first capacitor; a first end of the first capacitor is electrically connected with the second pole of the seventh switch tube; a ninth switch tube; a first pole of the ninth switch tube is electrically connected with a second end of the first capacitor, and a second pole of the ninth switch tube is grounded; a tenth switch tube; a first pole of the tenth switch tube is electrically connected with the first pole of the seventh switch tube, and a second pole of the tenth switch tube is electrically connected with the second end of the first capacitor.

12. The wireless charging circuit of any one of claims 1-10, wherein, Any one of the at least one stage of the switched capacitor DC-DC converter comprises: a seventh switch tube; a first pole of the seventh switch tube is used as an input end of the switched capacitor DC-DC converter; an eighth switch tube; a first pole of the eighth switch tube is electrically connected with a second pole of the seventh switch tube, and a second pole of the eighth switch tube is used as an output end of the switched capacitor DC-DC converter; a first capacitor; a first end of the first capacitor is electrically connected with the second pole of the seventh switch tube; a ninth switch tube; a first pole of the ninth switch tube is electrically connected with a second end of the first capacitor, and a second pole of the ninth switch tube is electrically connected with the second pole of the eighth switch tube; a tenth switch tube; a first pole of the tenth switch tube is electrically connected with the first pole of the seventh switch tube, and a second pole of the tenth switch tube is electrically connected with the second end of the first capacitor; an eleventh switch tube; a second pole of the eleventh switch tube is electrically connected with the first pole of the seventh switch tube; a twelfth switch tube; a first pole of the twelfth switch tube is grounded, and a second pole of the twelfth switch tube is electrically connected with a first pole of the eleventh switch tube; a second capacitor; a first end of the second capacitor is electrically connected with the first pole of the eleventh switch tube; a thirteenth switch tube; a first pole of the thirteenth switch tube is grounded, and a second pole of the thirteenth switch tube is electrically connected with a second end of the second capacitor; a fourteenth switch tube; a first pole of the fourteenth switch tube is electrically connected with a second end of the second capacitor, and a second pole of the fourteenth switch tube is electrically connected with a second pole of the eleventh switch tube.

13. The wireless charging circuit according to claim 11 or 12, wherein, the at least one-stage switched capacitor DC converter comprises a first-stage switched capacitor DC converter and a second-stage switched capacitor DC converter, and an output end of the first-stage switched capacitor DC converter is electrically connected with an input end of the second-stage switched capacitor DC converter; the second voltage conversion circuit further comprises a third voltage boosting circuit, and the third voltage boosting circuit is in parallel connection with the first voltage boosting circuit; a boosting multiple of the third voltage boosting circuit is the same as a boosting multiple of the first voltage boosting circuit; the wireless charging circuit further comprises: a first diode, an anode of the first diode is electrically connected with an output end of the first voltage boosting circuit, and a cathode of the first diode is electrically connected with the first AC-DC conversion circuit; a second diode, an anode of the second diode is electrically connected with an output end of the third voltage boosting circuit, and a cathode of the second diode is electrically connected with the first AC-DC conversion circuit.

14. The wireless charging circuit of any one of claims 1-13, wherein, the wireless charging circuit further comprises a third diode, an anode of the third diode is electrically connected with an input end of the switched capacitor DC converter, and a cathode of the third diode is electrically connected with an output end of the switched capacitor DC converter.

15. The wireless charging circuit of claim 3, wherein, the wireless charging circuit further comprises: a first thermistor for sensing a temperature of the first battery; a second thermistor for sensing a temperature of the first voltage boosting circuit and a processor.

16. An electronic device, comprising: the wireless charging circuit according to any one of claims 1-15; and a first coil electrically connected with the first AC-DC conversion circuit, the first coil being configured to emit an alternating magnetic field and to receive an alternating magnetic field and generate an alternating current.

17. The electronic device according to claim 16, wherein, the wireless charging circuit further comprises: a second voltage boosting circuit electrically connected with the first voltage conversion circuit and configured to boost and output a voltage of the first battery; wherein a boosting multiple of the second voltage boosting circuit is less than or equal to a boosting multiple of the first voltage boosting circuit; a second AC-DC conversion circuit electrically connected with the second voltage boosting circuit and configured to convert a direct current voltage output by the second voltage boosting circuit into an alternating current voltage; the electronic device further comprises: a second coil electrically connected with the second AC-DC conversion circuit and configured to emit an alternating magnetic field.

18. The electronic device of claim 16 or 17, wherein, the electronic device further comprises: a first battery electrically connected with the first voltage conversion circuit in the wireless charging circuit.

19. The electronic device of claim 18, wherein, the electronic device further comprises a circuit board and a housing, and the housing covers the circuit board and the first battery; the wireless charging circuit is arranged on the circuit board, and the first coil is located on a side of the first battery facing the housing and in contact with the housing.

20. A wireless charging system, comprising: the electronic device according to any one of claims 16-19; and the second electronic device comprises: a second battery; a third coil configured to emit an alternating magnetic field to the first coil in the first electronic device or receive the alternating magnetic field emitted by the first coil; a third AC-DC conversion circuit electrically connected to the third coil and the second battery, configured to convert an AC voltage induced by the third coil after receiving an AC magnetic field into a DC voltage to charge the second battery; the third AC-DC conversion circuit is also configured to convert a battery voltage provided by the second battery into an AC voltage and transmit the AC voltage to the third coil, so that the third coil emits an alternating magnetic field.

21. The wireless charging system of claim 20, wherein, The first electronic device comprises a second voltage boosting circuit, a second AC-DC conversion circuit and a second coil; the second voltage boosting circuit is electrically connected to the first voltage conversion circuit in the first electronic device and is configured to output a boosted voltage of the output voltage of the first voltage conversion circuit; wherein the voltage boosting multiple of the second voltage boosting circuit is less than or equal to the voltage boosting multiple of the first voltage boosting circuit; the second AC-DC conversion circuit is electrically connected to the second voltage boosting circuit and is configured to convert a DC voltage output by the second voltage boosting circuit into an AC voltage; and the second coil is electrically connected to the second AC-DC conversion circuit and is configured to emit an alternating magnetic field. The wireless charging system further comprises a third electronic device, wherein the third electronic device comprises: a third battery; a fourth coil configured to receive the alternating magnetic field emitted by the second coil; a fourth AC-DC conversion circuit electrically connected to the fourth coil and the third battery, configured to convert an AC voltage induced by the fourth coil after receiving an AC magnetic field into a DC voltage to charge the third battery.

22. A control method characterized by, The control method is applied to a processor in the electronic device of any one of claims 16-19, wherein the electronic device further comprises a first battery electrically connected to the processor, the first battery is electrically connected to a first voltage conversion circuit in the wireless charging circuit; the first voltage boosting circuit and the at least one stage of switched capacitor DC-DC converter are electrically connected between the first voltage conversion circuit and the first AC-DC conversion circuit in sequence; The method comprises: after receiving a control operation of a user, if the power of the first battery is greater than a minimum power threshold, controlling the first voltage conversion circuit to output a first battery voltage provided by the first battery; the control operation is used to control the first battery to discharge; controlling the first voltage boosting circuit to boost the first battery voltage and controlling the at least one stage of switched capacitor DC-DC converter to output the voltage output by the first voltage boosting circuit; after receiving a power boost request, controlling the at least one stage of switched capacitor DC-DC converter to boost the voltage output by the first voltage boosting circuit; controlling the first AC-DC conversion circuit to convert the voltage output by the at least one stage of switched capacitor DC-DC converter into an AC voltage to excite the first coil to emit an alternating magnetic field.

23. The control method according to claim 22, wherein The wireless charging circuit further comprises a second voltage boosting circuit, a second AC-DC conversion circuit and a second coil; the second voltage boosting circuit is electrically connected with the first voltage conversion circuit; the second AC-DC conversion circuit is electrically connected with the second voltage boosting circuit; and the second coil is electrically connected with the second AC-DC conversion circuit; The method further comprises detecting whether the position where the second coil is located has an electronic device to be charged; If the position where the second coil is located has the electronic device to be charged, after the first voltage conversion circuit outputs the first battery voltage provided by the first battery, the method further comprises: controlling the second voltage boosting circuit to boost the first battery voltage; wherein the voltage output by the second voltage boosting circuit is less than or equal to the voltage output by the first voltage boosting circuit; The second AC-DC conversion circuit converts the DC voltage output by the second voltage boosting circuit into an AC voltage to excite the second coil to emit an alternating magnetic field.

24. The control method according to claim 22 or 23, characterized by, The wireless charging circuit further comprises a first switch circuit and a second switch circuit; a first end of the first switch circuit is electrically connected with an input end of the first voltage conversion circuit, and a second end of the first switch circuit is electrically connected between the first voltage boosting circuit and the at least one-stage switched capacitor DC converter; a first end of the second switch circuit is electrically connected with the first voltage boosting circuit, and a second end of the second switch circuit is electrically connected with the at least one-stage switched capacitor DC converter; After receiving the control operation of the user, before controlling the first voltage conversion circuit to output the first battery voltage provided by the first battery, the method comprises: generating a first switch control signal and a second switch control signal according to the control operation; outputting the first switch control signal to a control end of the first switch circuit to control the first switch circuit to be turned off; outputting the second switch control signal to a control end of the second switch circuit to control the second switch circuit to be turned on, and electrically connecting the first voltage boosting circuit with the at least one-stage switched capacitor DC converter.

25. The control method according to claim 23, wherein Before receiving the control operation of the user, the control method further comprises: sending a detection signal; the detection signal is used to connect the electronic device and the electronic device to be charged; if the electronic device and the electronic device to be charged are successfully wirelessly connected, outputting instruction request information; the instruction request information is used to instruct the user to input the control operation.

26. The control method according to claim 23, wherein The wireless charging circuit further comprises a third switch circuit; a first end of the third switch circuit is electrically connected with a USB interface, and a second end of the third switch circuit is electrically connected with an output end of the second voltage boosting circuit; the USB interface is used to be electrically connected with an external device and identify the type of the external device; If the USB interface is electrically connected with the external device, the method further comprises: generating a third switch control signal according to the identification result of the type of the external device by the USB interface; outputting the third switch control signal to a control end of the third switch circuit to control the third switch circuit to be turned on, and electrically connecting the USB interface with the second voltage boosting circuit; The method further comprises, after the first voltage conversion circuit is controlled to output the first battery voltage provided by the first battery, controlling the second voltage boost circuit to boost the first battery voltage and transmit the boosted first battery voltage to the external device through the third switch circuit.

27. The control method according to claim 23, 25 or 26, characterized by, The wireless charging circuit further comprises a fourth switch circuit, a first end of the fourth switch circuit is electrically connected to an output end of the second voltage boost circuit, and a second end of the fourth switch circuit is electrically connected to the second AC-DC conversion circuit. Before the second voltage boost circuit is controlled to boost the first battery voltage after the position where the second coil is located is detected to have the electronic device to be charged, the method further comprises: generating a fourth switch control signal; outputting the fourth switch control signal to a control end of the fourth switch circuit to control the fourth switch circuit to be turned on, and electrically connecting the second voltage boost circuit and the second AC-DC conversion circuit.

28. The control method according to claim 24, wherein Before the control operation of the user is received, the method further comprises: generating the second switch control signal and outputting the second switch control signal to a control end of the second switch circuit to control the second switch circuit to be turned off; if the position where the first coil is located has a wireless charging power supply, generating the first switch control signal; outputting the first switch control signal to a control end of the first switch circuit to control the first switch circuit to be turned on, and electrically connecting the at least one-stage switched capacitor DC converter and the input end of the first voltage conversion circuit; controlling the at least one-stage switched capacitor DC converter to transmit the DC voltage output by the first AC-DC conversion circuit to the first voltage conversion circuit; controlling the first voltage conversion circuit to convert the DC voltage output by the first AC-DC conversion circuit into the first battery voltage of the first battery and apply the first battery voltage to the first battery to charge the first battery.

29. The control method according to claim 22, wherein The wireless charging circuit further comprises a first switch circuit and a fifth switch circuit, a first end of the first switch circuit is electrically connected to an input end of the first voltage conversion circuit, a second end of the first switch circuit is electrically connected between the first voltage boost circuit and the at least one-stage switched capacitor DC converter, a first end of the fifth switch circuit is electrically connected to a USB interface, and a second end of the fifth switch circuit is electrically connected to the input end of the first voltage conversion circuit; the USB interface is used to be electrically connected to an external device and identify a type of the external device. If the USB interface is electrically connected to the external device, the method further comprises: generating a first switch control signal and a fifth switch control signal according to an identification result of the type of the external device by the USB interface; outputting the first switch control signal to a control end of the first switch circuit to control the first switch circuit to be turned off; and outputting the fifth switch control signal to a control end of the fifth switch circuit to control the fifth switch circuit to be turned on. The fifth switch control signal is output to a control end of the fifth switch circuit to control the fifth switch circuit to be turned on, so that the USB interface is electrically connected with an input end of the first voltage conversion circuit, and a power supply voltage provided by the external device is transmitted to the input end of the first voltage conversion circuit through the fifth switch circuit.

30. The control method of claim 22, wherein The wireless charging circuit further comprises a first thermistor configured to sense a temperature of the first battery. After the first AC-DC conversion circuit is controlled to convert the voltage output by the at least one-stage switched-capacitor DC converter into an AC voltage, the method further comprises: According to a sensing result of the first thermistor, if the temperature of the first battery is greater than a first temperature threshold, the at least one-stage switched-capacitor DC converter is controlled to output the voltage output by the first voltage boost circuit. If the temperature of the first battery is less than the first temperature threshold, the at least one-stage switched-capacitor DC converter is controlled to maintain a state of boosting the voltage output by the first voltage boost circuit.

31. The control method of claim 30, wherein If the temperature of the first battery is greater than the first temperature threshold and the at least one-stage switched-capacitor DC converter outputs the voltage output by the first voltage boost circuit, the method further comprises: if the temperature of the first battery is greater than a second temperature threshold, the first voltage boost circuit is turned off; and wherein the second temperature threshold is greater than the first temperature threshold.

32. The control method of any one of claims 22-31, wherein The method further comprises: if the power of the first battery is less than the minimum power threshold, the first voltage boost circuit is turned off, and low-power indication information is output; and the low-power indication information is used to indicate that the power of the first battery is less than the minimum power threshold.

33. The control method of claim 22, wherein The first voltage boost circuit has a feedback end; the second voltage conversion circuit further comprises: a pull-up resistor, a pull-down resistor, and a regulation resistor; a first end of the pull-up resistor is electrically connected with an output end of the first voltage boost circuit, and a second end of the pull-up resistor is electrically connected with the feedback end of the first voltage boost circuit; a first end of the pull-down resistor is electrically connected with the feedback end of the first voltage boost circuit, and a second end of the pull-down resistor is grounded; and a first end of the regulation resistor is electrically connected with the feedback end of the first voltage boost circuit. Before the first voltage boost circuit is controlled to boost the voltage of the first battery and the at least one-stage switched-capacitor DC converter is controlled to output the voltage output by the first voltage boost circuit, the method further comprises: a second end of the regulation resistor is controlled to be suspended.

34. The control method of claim 33, wherein Before the at least one-stage switched-capacitor DC converter is controlled to boost the voltage output by the first voltage boost circuit after the power boost request is received, the method further comprises: the second end of the regulation resistor is grounded.

35. The control method of claim 33, wherein After the power boost request is received, before the at least one stage of switched capacitor DC-DC converter boosts the voltage output by the first boost circuit, the method further includes providing a pulse width modulation signal to the second end of the regulating resistor.

36. A computer-readable storage medium, characterized in that, comprising computer instructions that, when executed on a processor in an electronic device, cause the processor to perform the control method of any of claims 22-35.

37. A computer program product, characterised in that, comprising computer instructions that, when executed on a processor in an electronic device, cause the processor to perform the control method of any of claims 22-35.

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