Wireless charging circuit, wireless charging module and electronic equipment

Abstract

The present application discloses a wireless charging circuit, a wireless charging module and an electronic device, which relate to the field of wireless charging technology. The wireless charging circuit includes a first switch device, a first unidirectional device, a first capacitor and a first coil. When the first switch device is in the on state, the alternating current output by the alternating current power source passes through the first switch device or the first unidirectional device, and radiates electromagnetic energy into space through the first capacitor and the first coil; when the first switch device is in the off state, the alternating current power source charges the first capacitor to a preset voltage through the first unidirectional device, and stops radiating electromagnetic energy into space. Based on the solution of the present application, the on and off of the wireless charging path can be achieved through a switch device, a unidirectional device and a capacitor, so that the number of electronic devices used in the wireless charging circuit is small, the cost is low, and the volume is small. Therefore, it is more suitable for the future development trend of miniaturization and low cost of electronic equipment.

Description

Technical Field

[0001] The present application relates to the field of wireless charging technology, and in particular, to a wireless charging circuit, a wireless charging module and an electronic device. Background Art

[0002] With the continuous advancement of science and technology, in order to improve the convenience of users in using electronic devices, in addition to the functions of electronic devices themselves, the charging methods of electronic devices are also constantly innovating. For example, for a stylus or keyboard used with a tablet computer, in addition to charging it through the tablet computer in a wired manner, it can also be charged wirelessly through the tablet computer.

[0003] When a tablet computer is wirelessly charging a stylus or keyboard, only one of the electronic devices in the stylus or keyboard can be charged at the same time. Since the stylus and keyboard have different wireless charging paths, a wireless charging circuit is needed to control the wireless charging path of the tablet computer, allowing only one wireless charging path to be turned on at a time. However, existing wireless charging circuits generally use dual MOSFETs to turn on and off the wireless charging path, which requires more electronic components, has a higher overall cost and a larger size, and is not suitable for the development trend of miniaturization and low cost of electronic devices.

[0004] Therefore, a new solution is urgently needed to solve the above problems. Summary of the invention

[0005] The present application provides a wireless charging circuit, a wireless charging module and an electronic device, which can realize the conduction and disconnection of the wireless charging path through a switch device, a unidirectional device and a capacitor. As a result, the number of electronic devices used in the wireless charging circuit is small, the cost is low, and the volume is small. Therefore, it is more suitable for the future development trend of miniaturization and low cost of electronic equipment.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, a wireless charging circuit is provided, comprising a first switching device, a first unidirectional device, a first capacitor and a first coil. The first end of the first switching device is connected to the first power supply end of the AC power supply and the first end of the first unidirectional device. The second end of the first switching device is connected to the first plate of the first capacitor and the second end of the first unidirectional device. The second plate of the first capacitor is connected to the first end of the first coil. The second end of the first coil is connected to the second power supply end of the AC power supply. When the first switching device is in an on state, the AC power output by the AC power supply passes through the first switching device or the first unidirectional device, and radiates electromagnetic energy into space through the first capacitor and the first coil. When the first switching device is in an off state, the AC power supply charges the first capacitor to a preset voltage through the first unidirectional device, and stops radiating electromagnetic energy into space.

[0008] In the embodiment of the present application, the on and off of the wireless charging circuit is controlled according to the on and off of the first switching device and the first unidirectional device and the first capacitor. When the first switching device is in the on state, the current output by the AC power supply can pass through the first switching device or the first unidirectional device, and radiate electromagnetic energy to the space through the first capacitor and the first coil, so that the terminal device that is wirelessly connected to the wireless charging circuit can be wirelessly charged. When the first switching device is in the off state, the AC power output by the AC power supply can charge the first capacitor to a preset voltage through the first unidirectional device, and stop radiating electromagnetic energy to the space, thereby stopping wireless charging to the terminal device that is wirelessly connected to the wireless charging circuit. Therefore, through the wireless charging circuit, not only can the on and off of the wireless charging path be realized, but also fewer electronic devices are required, the overall cost of the wireless charging circuit is low, the volume is small, and it is more suitable for the development trend of miniaturization and low cost of electronic equipment.

[0009] In combination with the first aspect, in some implementations of the first aspect, the wireless charging circuit includes a first PMOSFET, the first PMOSFET includes a transistor structure and a parasitic diode, the first switching device is a transistor structure, and the first unidirectional device is a parasitic diode.

[0010] In this implementation, a first PMOSFET can include a first switch device and a first unidirectional device at the same time, that is, a transistor structure is used as a first switch device, and a parasitic diode is used as a first unidirectional device, so that when the transistor structure is in an on state, electromagnetic energy is radiated into space through the transistor structure and the parasitic diode in conjunction with the first capacitor and the first coil. When the transistor structure is in an off state, the first capacitor is charged to a preset voltage through the parasitic diode, and electromagnetic energy is stopped from being radiated into space.

[0011] In combination with the first aspect, in some implementations of the first aspect, the wireless charging circuit also includes a second switching device, a first end of the second switching device is connected to the control end of the first switching device, and a second end of the second switching device is grounded; when the second switching device is in an on state, the first switching device is also in an on state.

[0012] In this implementation, the second switch device serves as an auxiliary device. When the second switch device is turned on, the first switch device is also turned on, thereby putting the wireless charging circuit in an on state. When the second switch device is turned off, the first switch device is also turned off, thereby putting the wireless charging circuit in an off state.

[0013] In combination with the first aspect, in some implementations of the first aspect, the second switching device includes a second NMOSFET, a drain of the second NMOSFET is connected to the control terminal of the first switching device, and a source of the second NMOSFET is grounded.

[0014] In this implementation, the second NMOSFET is used as the second switching device, and the on state or off state of the second NMOSFET is controlled according to a control signal received by the gate of the second NMOSFET, thereby controlling the on or off state of the first switching device.

[0015] In combination with the first aspect, in some implementations of the first aspect, the wireless charging circuit also includes a first resistor and a second resistor, the first end of the first resistor and the first end of the second resistor are both connected to the control end of the first switching device, and the second end of the second resistor is connected to the second end of the first switching device.

[0016] In this implementation, the first resistor and the second resistor are used as voltage-dividing resistors, and the voltage between the control terminal and the second terminal of the first switching device is adjusted according to the resistance ratio of the first resistor and the second resistor.

[0017] In combination with the first aspect, in some implementations of the first aspect, the wireless charging circuit also includes a second capacitor, a first end of the second capacitor is connected to the control end of the first switching device, and a second end of the second capacitor is connected to the second end of the first switching device.

[0018] In this implementation, the second capacitor is used as a voltage stabilizing capacitor to stabilize the voltage between the control terminal and the second terminal of the first switching device.

[0019] In the second aspect, a wireless charging module is provided, including a control module and multiple wireless charging circuits; the control module is connected to the multiple wireless charging circuits respectively; the control module is used to control one of the multiple wireless charging circuits to be turned on; when the wireless charging circuit is in the turned-on state, it is used to radiate electromagnetic energy into space.

[0020] In the embodiment of the present application, the control module is used to output a control signal to control one of the multiple wireless charging circuits to be turned on and the other wireless charging circuits to be turned off. The wireless charging circuit is turned on according to the control signal of the control module and radiates electromagnetic energy into space to wirelessly charge the corresponding terminal device, thereby effectively reducing the number of electronic components used in the wireless charging module, reducing the cost and size, and therefore, more suitable for the future development trend of miniaturization and low cost of electronic equipment.

[0021] In combination with the second aspect, in some implementations of the second aspect, the wireless charging circuit includes at least one of a stylus charging circuit and a wireless keyboard charging circuit, and only one of the stylus charging circuit and the wireless keyboard charging circuit is turned on at a time.

[0022] In an embodiment of the present application, when the wireless charging circuit includes a stylus charging circuit and the stylus charging circuit is turned on, the AC power supply is used to wirelessly charge the stylus through the stylus charging circuit. When the wireless charging circuit includes a wireless keyboard charging circuit and the wireless keyboard charging circuit is turned on, the AC power supply is used to wirelessly charge the wireless keyboard through the wireless keyboard charging circuit. When the wireless charging circuit includes a stylus charging circuit and a wireless keyboard charging circuit, only one of the stylus charging circuit and the wireless keyboard charging circuit is turned on at a time, and the AC power supply is used to wirelessly charge the stylus through the stylus charging circuit, or the AC power supply is used to wirelessly charge the wireless keyboard through the wireless keyboard charging circuit.

[0023] In combination with the second aspect, in certain implementations of the second aspect, the wireless charging module also includes a first packaging structure and a second packaging structure, one of the first switching devices in the two wireless charging circuits is encapsulated in the first packaging structure, and the other of the first switching devices in the two wireless charging circuits is encapsulated in the second packaging structure.

[0024] In the embodiment of the present application, the first switch devices in the two wireless charging circuits can be independently packaged in the first packaging structure and the second packaging structure. For example, the two first switch devices can be two separately packaged PMOSFETs, which are respectively connected to the two wireless charging circuits.

[0025] In combination with the second aspect, in some implementations of the second aspect, the wireless charging module also includes a third packaging structure, and the first switching devices in the two wireless charging circuits are both packaged in the third packaging structure.

[0026] In the embodiment of the present application, the first switch devices in the two wireless charging circuits are packaged together in a third packaging structure. For example, the two first switch devices can be a combined packaged dual PMOSFET, which is connected to the two wireless charging circuits respectively.

[0027] In a third aspect, an electronic device is provided, including a wireless charging circuit or a wireless charging module, and the electronic device also includes a battery. The wireless charging circuit or the wireless charging module is used to convert the electric energy of the battery into electromagnetic energy and radiate it into space.

[0028] In the embodiment of the present application, the wireless charging circuit or wireless charging module can realize the conduction and disconnection of the wireless charging path through a switching device, a unidirectional device and a capacitor, so as to convert the electric energy stored in the battery into electromagnetic energy and transmit it into space, thereby effectively reducing the electronic devices used in electronic devices, reducing the cost of electronic devices, and reducing the size of electronic devices, which is more suitable for the development trend of miniaturization and low cost of electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a wireless charging scenario applicable to an embodiment of the present application;

[0030] Figure 2 A schematic diagram of another wireless charging scenario applicable to an embodiment of the present application;

[0031] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0032] Figure 4 This is a schematic diagram of the structure of a wireless charging module provided in an embodiment of the present application;

[0033] Figure 5 A circuit diagram of a wireless charging module provided in an embodiment of the present application;

[0034] Figure 6 A circuit diagram of a wireless charging circuit provided in an embodiment of the present application;

[0035] Figure 7 A circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application;

[0036] Figure 8 A circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application;

[0037] Fig. 9 A circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application;

[0038] Fig.10 A circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application;

[0039] Fig.11 A circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application;

[0040] Fig.12This is a structural schematic diagram of a wireless charging module provided in another embodiment of the present application;

[0041] Fig.13 A circuit diagram of a wireless charging module provided in another embodiment of the present application;

[0042] Fig.14 This is a simulation waveform diagram of a wireless charging module provided in an embodiment of the present application;

[0043] Fig.15 This is a measured waveform diagram of a wireless charging module provided in an embodiment of the present application;

[0044] Fig.16 A hardware system of a terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0046] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0047] In order to facilitate the understanding of the embodiments of the present application, the relevant concepts involved in the embodiments of the present application are first briefly described.

[0048] 1. Wireless charging technology

[0049] In the field of communications, wireless charging technology generally refers to the technology of charging electrical devices through electromagnetic fields or electromagnetic waves without physical wires. Specifically, wireless charging can be divided into electromagnetic induction, electromagnetic resonance, and radio wave. Electromagnetic induction generally generates current through the primary coil and the secondary coil, thereby transferring energy from the transmitting end to the receiving end. However, the transmission distance of electromagnetic induction is generally short, and the power loss during the charging process will gradually increase as the transmission distance increases. For example, the wireless charging process of a mobile phone by a wireless charger, or the wireless charging process of a stylus or keyboard by a tablet. Electromagnetic resonance generally transmits energy efficiently through two objects with the same vibration frequency. When the transmitter and the receiver vibrate at the same frequency, the receiver obtains energy from the electromagnetic field generated by the transmitter and converts it into current to power or charge the mobile device. For example, the wireless charging process of most electric vehicles. Radio wave type generally converts electromagnetic waves into electrical energy through a rectifier circuit to charge electrical devices.

[0050] 2. Metal oxide semiconductor field effect transistor (MOSFET), hereinafter referred to as "MOS tube".

[0051] In the field of communications, MOS tube refers to a voltage-driven semiconductor device. MOS tubes generally have three electrodes, namely: gate G, source S and drain D. MOS tubes can be divided into PMOS tubes and NMOS tubes according to their semiconductor structure. In general electronic circuits, MOS tubes are usually used in amplifier circuits or switching circuits. As a voltage-controlled element, when the voltage loaded on the gate of the MOS tube exceeds the preset value, the source and drain of the MOS tube can conduct current. For example, when the voltage received by the gate of the NMOS tube is greater than the preset value, the source and drain of the NMOS tube are conducted; when the voltage received by the gate of the NMOS tube is not greater than the preset value, the source and drain of the NMOS tube are cut off. When the voltage received by the gate of the PMOS tube is less than the preset value, the source and drain of the PMOS tube are conducted; when the voltage received by the gate of the PMOS tube is not less than the preset value, the source and drain of the PMOS tube are cut off.

[0052] The above is a brief introduction to the terms involved in the embodiments of the present application, which will not be repeated below.

[0053] Combine the following Figures 1 to 4 , firstly, the application scenarios of the embodiments of the present application and the structure of the electronic device to which they are applied are introduced.

[0054] Figure 1 A schematic diagram of a wireless charging scenario applicable to an embodiment of the present application.

[0055] like Figure 1 As shown, the user can use the electronic device 10 to wirelessly charge the stylus 20. When the stylus 20 is within a preset distance of the electronic device 10 and is recognized and connected by the electronic device 10, the electronic device 10 can wirelessly charge the stylus 20. When the stylus 20 is away from the electronic device 10 beyond the preset distance, the electronic device 10 stops wirelessly charging the stylus 20. The embodiment of the present application does not specifically limit the type of the electronic device 10. In some embodiments, the electronic device 10 can be a mobile phone, a wearable device (such as a smart bracelet, a smart watch, a headset, etc.), a tablet computer, a laptop computer, a handheld computer, a notebook computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a cellular phone, a personal digital assistant (personal digital assistant, PDA), an augmented reality (Augmented reality, AR)\virtual reality (virtual reality, VR) device and other IOT (internet of things, Internet of Things) devices, and can also be a TV, a large screen, a printer, a projector and other devices. For ease of understanding, the following embodiments take the electronic device 10 as a tablet computer as an example for exemplary description.

[0056] Figure 2 The present invention is a schematic diagram of another wireless charging scenario applicable to an embodiment of the present application.

[0057] like Figure 2 As shown, the user can use the electronic device 10 to wirelessly charge the wireless keyboard 30. When the wireless keyboard 30 is within a preset distance from the electronic device 10 and is recognized and connected by the electronic device 10, the electronic device 10 can wirelessly charge the wireless keyboard 30. When the wireless keyboard 30 is beyond the preset distance from the electronic device 10, the electronic device 10 stops wirelessly charging the wireless keyboard 30.

[0058] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0059] like Figure 3 As shown, the electronic device 10 may include a central processing unit 100 (CPU), a wireless charging module 200, and a battery 300, etc., and these devices may be coupled through various interconnection buses or other electrical connection methods. For example, the wireless charging module 200 is electrically connected to the central processing module 100 and the battery 300, respectively, and the wireless charging module 200 is also wirelessly connected to the stylus 20 and the wireless keyboard 30, respectively.

[0060] The central processing module 100 is one of the main devices of a personal computer and is a core component in a personal computer. Its main function is to interpret computer instructions and process data in computer software. The CPU is responsible for reading instructions for all operations in a personal computer and is the core component that decodes and executes instructions. A program is a sequence of instructions, and executing a program is to execute instructions one by one according to the instruction sequence. Once the program is loaded into the main memory, the CPU can automatically complete the task of reading instructions from the main memory and executing instructions. At the same time, the function of an instruction is often realized by a series of operations performed by components in a personal computer. The CPU will generate corresponding operation control signals according to the function of the instruction and send them to the corresponding components, thereby controlling these components to act according to the requirements of the instruction.

[0061] Exemplarily, the central processing module 100 may include an arithmetic logic unit, a register unit, an operator, and a control unit. The arithmetic logic unit may perform fixed-point or floating-point arithmetic operations, shift operations, and logic operations, and may also perform address operations and conversions. The register unit includes a general register, a special register, and a control register. The control unit is mainly responsible for decoding instructions and issuing control signals for each operation to be performed to complete each instruction.

[0062] The wireless charging module 200 is a charging module provided inside the electronic device 10. The wireless charging module 200 may include a wireless charging receiving unit and / or a wireless charging transmitting unit, and the wireless charging receiving unit and the wireless charging transmitting unit are respectively connected to the central processing module 100. The wireless charging receiving unit is used to sense the external magnetic field energy according to the receiving coil and convert it into electric energy and store it in the battery 300. For example, when the electronic device 10 is a mobile phone, the magnetic field energy from the wireless charger can be received by the wireless charging receiving unit and the mobile phone can be wirelessly charged, and the electric energy can be stored in the battery 300. The wireless charging transmitting unit is used to transmit the electric energy of the battery 300 to the external space through the transmitting coil. For example, when the electronic device 10 is a tablet computer, the electric energy of the battery 300 can be converted into magnetic field energy and transmitted to the external space through the wireless charging transmitting coil of the wireless charging transmitting unit, so that the stylus 20 or the wireless keyboard 30 can be wirelessly charged. Correspondingly, a wireless charging receiving coil is also provided inside the stylus 20 or the wireless keyboard 30 to receive the magnetic field energy and convert it into electric energy for use by the stylus 20 or the wireless keyboard 30.

[0063] The wireless charging transmitting unit (TX) may be an electronic device with a wireless charging transmitter, such as a tablet computer. The wireless charging transmitting end may include a first MCU, a power full bridge, and a first LC resonant circuit. The first LC resonant circuit includes a transmitting end coil and a transmitting capacitor, and the transmitting end coil may be equivalent to a transmitting inductor. The input end of the wireless charging transmitting unit is a DC voltage, and the DC voltage generates an AC voltage, i.e., a square wave, through the power full bridge. The square wave is loaded at both ends of the first LC resonant circuit to generate an AC current, and the AC current generates a magnetic field through the transmitting end coil, thereby radiating magnetic field energy into space.

[0064] The wireless charging receiving unit (RX) can be an electronic device with wireless charging function, such as a stylus or keyboard. The wireless charging receiving end can include a second MCU, a rectifier bridge, a low dropout regulator (LDO), a charging chip, a battery, and a second LC resonant circuit, and the second LC resonant circuit includes a receiving coil and a receiving capacitor. The receiving coil senses the energy of the spatial magnetic field and generates an AC current in the second LC resonant circuit. The AC current is converted into a DC voltage through a rectifier bridge, and the DC voltage is then charged to the battery through a low dropout regulator and an electrical chip.

[0065] It should be understood that the above is only an example of the structure of the electronic device 10, and the electronic device 10 may also include other subsystems or devices, which can be configured and modified as needed, and the embodiments of the present application do not impose any limitations on this.

[0066] Figure 4 The present invention is a schematic diagram of the structure of a wireless charging module provided in an embodiment of the present application.

[0067] like Figure 4 As shown, the wireless charging module 200 includes a wireless charging transmitter chip 201 and a wireless charging unit 202. The wireless charging unit 202 includes a stylus charging circuit 2021 and a wireless keyboard charging circuit 2022. Both the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022 are connected to the wireless charging transmitter chip 201.

[0068] The wireless charging transmitter chip 201 is used to control the operation of the wireless charging unit 202, so that the electric energy stored in the battery 300 can be used to charge the stylus 20 or the wireless keyboard 30 through the wireless charging unit 202. Exemplarily, the wireless charging transmitter chip 201 is used to control the stylus charging circuit 2021 to be turned on or off, so as to wirelessly charge the stylus or stop wirelessly charging the stylus 20. The wireless charging transmitter chip 201 is also used to control the wireless keyboard charging circuit 2022 to be turned on or off, so as to wirelessly charge the wireless keyboard 30 or stop wirelessly charging the stylus.

[0069] When the stylus pen 20 approaches the electronic device 10 within a preset distance range and the Hall sensor in the electronic device 10 detects the stylus pen 20, the wireless charging transmitter chip 201 controls the stylus pen charging circuit 2021 to conduct the wireless charging path between the electronic device 10 and the stylus pen 20, so that the electronic device 10 wirelessly charges the stylus pen 20. When the wireless keyboard 30 approaches the electronic device 10 within a preset distance range and the Hall sensor in the electronic device 10 detects the wireless keyboard 30, the wireless charging transmitter chip 201 controls the wireless keyboard charging circuit 2022 to conduct the wireless charging path between the electronic device 10 and the wireless keyboard 30, so that the electronic device 10 wirelessly charges the wireless keyboard 30.

[0070] Combine the following Figure 5 , and then give a detailed introduction to the technical problems existing in related technologies.

[0071] Figure 5 A circuit diagram of a wireless charging module provided in an embodiment of the present application.

[0072] like Figure 5 As shown, the wireless charging module includes a wireless charging transmitter chip IC_Tx, a stylus charging circuit 2021 and a wireless keyboard charging circuit 2022. Among them, the stylus charging circuit 2021 includes a twenty-first PMOS tube Q21, a twenty-second PMOS tube Q22, a first capacitor C1 and a first coil L1. The gate of the twenty-first PMOS tube Q21 is connected to the gate of the twenty-second PMOS tube Q22. The drain of the twenty-first PMOS tube Q21 is connected to the first power supply terminal of the wireless charging transmitter chip IC_Tx. The source of the twenty-first PMOS tube Q21 is connected to the source of the twenty-second PMOS tube Q22, and the gate of the twenty-second PMOS tube Q22 is connected in series with the first capacitor C1 and the first coil L1 in sequence, and then connected to the second power supply terminal of the wireless charging transmitter chip IC_Tx.

[0073] When the gate of the twenty-first PMOS transistor Q21 and the gate of the twenty-second PMOS transistor Q22 are connected to the stylus pen conduction signal (i.e., a low-level signal), the stylus pen charging circuit 2021 is in a conduction state, and is used to radiate electromagnetic energy into space through a resonant circuit formed by the first capacitor C1 and the first coil L1, thereby wirelessly charging the stylus pen 20. When the gate of the twenty-first PMOS transistor Q21 and the gate of the twenty-second PMOS transistor Q22 are connected to the stylus pen disconnection signal (i.e., a high-level signal), the stylus pen charging circuit 2021 is in a disconnection state, stops radiating electromagnetic energy into space, thereby stopping wirelessly charging the stylus pen 20.

[0074] The wireless keyboard charging circuit 2022 includes a twenty-third PMOS tube Q23, a twenty-fourth PMOS tube Q24, a second capacitor C2, and a second coil L2. The gate of the twenty-third PMOS tube Q23 is connected to the gate of the twenty-fourth PMOS tube Q24. The drain of the twenty-third PMOS tube Q23 is connected to the first power supply terminal of the wireless charging transmitter chip IC_Tx. The source of the twenty-third PMOS tube Q23 is connected to the source of the twenty-fourth PMOS tube Q24. The gate of the twenty-fourth PMOS tube Q24 is connected in series with the second capacitor C2 and the second coil L2 in sequence, and then connected to the second power supply terminal of the wireless charging transmitter chip IC_Tx.

[0075] When the gate of the twenty-third PMOS tube Q23 and the gate of the twenty-fourth PMOS tube Q24 are connected to the wireless keyboard conduction signal (i.e., a low-level signal), the wireless keyboard charging circuit 2022 is in a conducting state, and is used to radiate electromagnetic energy into space through the resonant circuit formed by the second capacitor C2 and the second coil L2, thereby wirelessly charging the wireless keyboard 30. When the gate of the twenty-third PMOS tube Q23 and the gate of the twenty-fourth PMOS tube Q24 are connected to the wireless keyboard disconnection signal (i.e., a high-level signal), the wireless keyboard charging circuit 2022 is in a disconnected state, stops radiating electromagnetic energy into space, thereby stopping wireless charging the wireless keyboard 30.

[0076] However, in the above-mentioned wireless charging unit 202, the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022 both use two reverse-series PMOS tubes to realize the conduction and disconnection of the wireless charging path. A large number of electronic components are required, and the overall cost and volume of the wireless charging circuit are high. Therefore, it is not suitable for the development trend of miniaturization and low cost of the electronic device 10.

[0077] In view of this, an embodiment of the present application provides a wireless charging circuit, which can realize the conduction and shutdown of the wireless charging path through a switching device, a unidirectional device and a capacitor, thereby effectively reducing the number of electronic devices used in the wireless charging circuit, reducing the cost of the wireless charging circuit, and reducing the size of the wireless charging circuit. Therefore, it is more suitable for the development trend of miniaturization and low cost of electronic equipment.

[0078] Combine the following Figures 6 to 15 , and then the solution provided in the embodiment of the present application is introduced in detail.

[0079] Figure 6 A circuit diagram of a wireless charging circuit provided in an embodiment of the present application.

[0080] like Figure 6As shown, in one embodiment provided in the present application, the wireless charging circuit 600 includes a first switch device 601, a first unidirectional device 602, a first capacitor C1 and a first coil L1. The first switch device 601 includes three terminals. The first terminal of the first switch device 601 is connected to the first power terminal of the AC power supply and the first terminal of the first unidirectional device 602, and is used to input the AC power when the first power terminal of the AC power supply outputs the AC power. The second terminal of the first switch device 601 is connected to the first plate of the first capacitor C1 and the second terminal of the first unidirectional device 602. The second plate of the first capacitor C1 is connected to the first terminal of the first coil L1. The second terminal of the first coil L1 is connected to the second power terminal of the AC power supply for outputting the AC power. The third terminal of the first switch device 601 is a control port. The first switch device 601 and the first unidirectional device 602 are used to cooperate with the first capacitor C1 and the first coil L1, and control whether to perform wireless charging to the corresponding terminal device according to the conduction and disconnection of the first switch device 601.

[0081] It should be understood that before the wireless charging circuit performs wireless charging, the terminal device corresponding to the electronic device first establishes a wireless connection with the electronic device including the wireless charging circuit. For example, before the tablet computer performs wireless charging to the stylus 20, the tablet computer first establishes a wireless connection with the stylus 20. Or before the tablet computer performs wireless charging to the wireless keyboard 30, the tablet computer first establishes a wireless connection with the wireless keyboard 30.

[0082] Exemplarily, when the first switch device 601 is in the on state, the first capacitor C1 and the first coil L1 form a resonant circuit, and the alternating current passes through the first switch device 601 or the first unidirectional device 602, and is converted into magnetic field energy through the first capacitor C1 and the first coil L1 and radiated into space, thereby wirelessly charging the corresponding terminal device (for example, the stylus 20 or the wireless keyboard 30). When the first switch device 601 is in the off state, the alternating current charges the first capacitor C1 to a preset voltage through the first unidirectional device 602, and stops radiating electromagnetic energy into space, thereby stopping wireless charging the corresponding terminal device.

[0083] Figure 7 This is a circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application.

[0084] like Figure 7As shown, in one embodiment provided in the present application, the wireless charging circuit 600 includes a first PMOS transistor Q1, a first capacitor C1 and a first coil L1. Among them, the first PMOS transistor Q1 includes a first transistor structure A1 and a first parasitic diode D1. The gate of the first transistor structure A1 is a control port, the drain of the first transistor structure A1 is connected to the first power supply terminal of the AC power supply and the positive electrode of the first parasitic diode D1, the source of the first transistor structure A1 is connected to the first plate of the first capacitor C1 and the negative electrode of the first parasitic diode D1, the second plate of the first capacitor C1 is connected to the first end of the first coil L1, and the second end of the first coil L1 is connected to the second power supply terminal of the AC power supply. The first PMOS tube Q1 (i.e., the first transistor structure A1 and the first parasitic diode D1) is used to cooperate with the first capacitor C1 and the first coil L1, and control whether to perform wireless charging to the corresponding terminal device according to the conduction and disconnection of the first transistor structure A1.

[0085] Exemplarily, when the gate of the first transistor structure A1 receives a low-level signal and the AC power of the AC power source is in a positive half-cycle, the gate-source voltage Vsg of the first transistor structure A1 is greater than the conduction threshold, and the AC power flows from the first power supply terminal of the AC power source to the second power supply terminal of the AC power source through the first parasitic diode D1. When the gate of the first transistor structure A1 receives a low-level signal and the AC power source is in a negative half-cycle, the gate-source voltage Vsg of the first transistor structure A1 is greater than the conduction threshold, the source and drain of the first transistor structure A1 are turned on, and the AC power flows from the second power supply terminal of the AC power source to the first power supply terminal of the AC power source through the first transistor structure A1. Therefore, in the process of the gate of the first transistor structure A1 receiving a low-level signal, the first capacitor C1 and the first coil L1 form a resonant circuit, and the AC power of the AC power source passes through the first transistor structure A1 or the first parasitic diode D1, and is converted into magnetic field energy through the first capacitor C1 and the first coil L1 and radiated to space, thereby wirelessly charging the corresponding terminal device (for example, the stylus 20 or the wireless keyboard 30).

[0086] When the gate of the first transistor structure A1 receives a high-level signal or does not receive a signal, and the AC power of the AC power source is in a positive half-cycle, when the AC power of the AC power source is powered on for the first time, the AC power of the AC power source will charge the first capacitor C1 to a preset voltage through the first parasitic diode D1. When the gate of the first transistor structure A1 receives a high-level signal or does not receive a signal, and the AC power of the AC power source is in a negative half-cycle, due to the unidirectional conduction characteristic of the body diode of the first parasitic diode D1, the first parasitic diode D1 is reversely cut off, and thus due to the characteristic of the first capacitor C1 that blocks direct current and passes alternating current, the wireless charging circuit 600 cannot form a wireless charging path, cannot radiate electromagnetic energy into space, and stops wirelessly charging the corresponding terminal device.

[0087] It should be understood that in some other embodiments, the first switch device 601 may also be an electronic device such as a thyristor, a triode, or an insulated gate bipolar transistor (IGBT).

[0088] It should be understood that the preset voltage is the maximum voltage of the first capacitor C1.

[0089] Figure 8 This is a circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application.

[0090] like Figure 8 As shown, in one embodiment provided in the present application, the wireless charging circuit 600 includes a first switch device 601, a first unidirectional device 602, a first capacitor C1, a first coil L1 and a second switch device 603, and the first switch device 601 includes three terminals. The first terminal of the first switch device 601 is connected to the first power terminal of the AC power supply and the first terminal of the first unidirectional device 602, and is used to input the AC power when the first power terminal of the AC power supply outputs the AC power. The second terminal of the first switch device 601 is connected to the first plate of the first capacitor C1 and the second terminal of the first unidirectional device 602. The second plate of the first capacitor C1 is connected to the first terminal of the first coil L1. The second terminal of the first coil L1 is connected to the second power terminal of the AC power supply for outputting the AC power. The third terminal of the first switch device 601 is connected to the first terminal of the second switch device 603. The second terminal of the second switch device 603 is grounded, and the third terminal of the second switch device 603 is a control port. The second switch device 603 is used to receive a control signal and turn on or off according to the control signal, thereby controlling the on and off of the first switch device 601 through the on and off of the second switch device 603. The first switch device 601 and the first unidirectional device 602 are used to cooperate with the first capacitor C1 and the first coil L1, and control whether to perform wireless charging on the corresponding terminal device according to the on and off of the first switch device 601.

[0091] Exemplarily, when the second switch device 603 is in the on state, the second switch device 603 is also in the on state. At this time, the first capacitor C1 and the first coil L1 form a resonant circuit, and the alternating current passes through the first switch device 601 or the first unidirectional device 602, and is converted into magnetic field energy through the first capacitor C1 and the first coil L1 and radiated into space, thereby wirelessly charging the corresponding terminal device (for example, the stylus 20 or the wireless keyboard 30). When the second switch device 603 is in the off state, the second switch device 603 is also in the off state. At this time, the alternating current charges the first capacitor C1 to a preset voltage through the first unidirectional device 602, and stops radiating electromagnetic energy into space, thereby stopping wireless charging to the corresponding terminal device.

[0092] Fig. 9 This is a circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application.

[0093] like Fig. 9 As shown, in one embodiment provided in the present application, the wireless charging circuit 600 includes a first PMOS transistor Q1, a first capacitor C1, a first coil L1, and a second NMOS transistor Q2, wherein the first PMOS transistor Q1 includes a first transistor structure A1 and a first parasitic diode D1. The drain of the first transistor structure A1 is connected to the first power supply terminal of the AC power supply and the positive electrode of the first parasitic diode D1, the source of the first transistor structure A1 is connected to the first plate of the first capacitor C1 and the negative electrode of the first parasitic diode D1, the second plate of the first capacitor C1 is connected to the first end of the first coil L1, and the second end of the first coil L1 is connected to the second power supply terminal of the AC power supply. The gate of the second NMOS transistor Q2 is a control port, the drain of the second NMOS transistor Q2 is connected to the first end of the first PMOS transistor Q1, and the source of the second NMOS transistor Q2 is grounded. The second NMOS transistor Q2 is used to receive a control signal and is turned on or off according to the control signal, thereby controlling the turning on and off of the first PMOS transistor Q1 by turning on and off the second NMOS transistor Q2. The first PMOS transistor Q1 (ie, the first transistor structure A1 and the first parasitic diode D1) is used to cooperate with the first capacitor C1 and the first coil L1, and controls whether to perform wireless charging on the corresponding terminal device according to the conduction and disconnection of the first transistor structure A1.

[0094] Exemplarily, when the gate of the second NMOS transistor Q2 receives a high level signal, the second NMOS transistor Q2 is turned on, so that the gate of the first transistor structure A1 receives a low level signal and is pulled low, and the first transistor structure A1 is turned on.

[0095] When the gate of the first transistor structure A1 receives a low-level signal and the AC power of the AC power source is in a positive half-cycle, the gate-source voltage Vsg of the first transistor structure A1 is greater than the conduction threshold, and the AC power flows from the first power supply terminal of the AC power source to the second power supply terminal of the AC power source through the first parasitic diode D1. When the gate of the first transistor structure A1 receives a low-level signal and the AC power source is in a negative half-cycle, the gate-source voltage Vsg of the first transistor structure A1 is greater than the conduction threshold, the source and drain of the first transistor structure A1 are turned on, and the AC power flows from the second power supply terminal of the AC power source to the first power supply terminal of the AC power source through the first transistor structure A1. Therefore, in the process of the gate of the first transistor structure A1 receiving a low-level signal, the first capacitor C1 and the first coil L1 form a resonant circuit, and the AC power of the AC power source passes through the first transistor structure A1 or the first parasitic diode D1, and is converted into magnetic field energy through the first capacitor C1 and the first coil L1 and radiated to space, thereby wirelessly charging the corresponding terminal device (such as the stylus 20 or the wireless keyboard 30).

[0096] When the gate of the second NMOS transistor Q2 receives a low-level signal, the second NMOS transistor Q2 is disconnected, so that the gate of the first transistor structure A1 receives a high-level signal and is pulled high. When the gate of the first transistor structure A1 receives a high-level signal or does not receive a signal, and the AC power of the AC power source is in a positive half-cycle, when the AC power of the AC power source is powered on for the first time, the AC power of the AC power source will charge the first capacitor C1 to a preset voltage through the first parasitic diode D1. When the gate of the first transistor structure A1 receives a high-level signal or does not receive a signal, and the AC power of the AC power source is in a negative half-cycle, due to the unidirectional conduction characteristic of the first parasitic diode D1, the first parasitic diode D1 is reversely cut off, and thus due to the characteristic of the first capacitor C1 that blocks direct current and passes alternating current, the wireless charging circuit 600 cannot form a wireless charging path, so that the wireless charging circuit 600 stops radiating electromagnetic energy into space and stops wirelessly charging the corresponding terminal device. It should be understood that in some other embodiments, the first switch device 601 may also be an electronic device such as a thyristor, a triode, or an insulated gate bipolar transistor (IGBT).

[0097] It should be understood that the preset voltage is the maximum voltage of the first capacitor C1.

[0098] Fig.10 This is a circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application.

[0099] like Fig.10As shown, in an embodiment provided in the present application, the wireless charging circuit 600 includes a first switch device 601, a first unidirectional device 602, a first capacitor C1 and a first coil L1. It should be noted that the embodiment of the present application is different from Figure 6 The difference between the wireless charging circuit shown is that the wireless charging circuit also includes a first resistor R1 and a second resistor R2, the first end of the first resistor R1 and the first end of the second resistor R2 are both connected to the control end of the first switch device 601, the second end of the first resistor R1 is the control port, and the second end of the second resistor R2 is connected to the second end of the first switch device 601.

[0100] In the embodiment of the present application, the first resistor R1 and the second resistor R2 form a voltage divider resistor, so that the voltage between the control terminal and the second terminal connected to the first switch device 601 is adjusted according to the resistance ratio of the first resistor R1 and the second resistor R2.

[0101] It should be understood that in the embodiment of the present application, for other specific implementations of the wireless charging circuit 600, reference can be made to the above description of the embodiment of the present application. Figure 6 The introduction of , I will not go into details here.

[0102] Fig.11 This is a circuit diagram of a wireless charging circuit provided in yet another embodiment of the present application.

[0103] like Fig.11 As shown, in an embodiment provided in the present application, the wireless charging circuit 600 includes a first switch device 601, a first unidirectional device 602, a first capacitor C1 and a first coil L1. It should be noted that the embodiment of the present application is different from Figure 6 The difference between the wireless charging circuit shown is that the wireless charging circuit further includes a second capacitor C2, a first end of the second capacitor C2 is connected to the control end of the first switch device 601, and a second end of the second capacitor C2 is connected to the second end of the first switch device 601.

[0104] In the embodiment of the present application, the second capacitor C2 is used as a voltage stabilizing capacitor to stabilize the voltage between the control terminal and the second terminal of the first switching device 601.

[0105] It should be understood that in the embodiment of the present application, for other specific implementations of the wireless charging circuit 600, reference can be made to the above description of the embodiment of the present application. Figure 6 The introduction of , I will not go into details here.

[0106] Fig.12 This is a structural schematic diagram of a wireless charging module provided in yet another embodiment of the present application.

[0107] like Fig.12As shown, in one embodiment provided in the present application, the wireless charging module 200 includes a control module 701 and a plurality of wireless charging circuits. The wireless charging circuit shown in the figure includes a first wireless charging circuit 600A and a second wireless charging circuit 600B. The first wireless charging circuit 600A and the second wireless charging circuit 600B are both Figures 6 to 11 The wireless charging circuit 600 shown. The control module 701 includes a power input terminal, a power output terminal and a control terminal. The power output terminal of the control module 701 is respectively connected to the AC power input terminals of multiple wireless charging circuits 600, and the power input terminal of the control module 701 is respectively connected to the AC power output terminals of multiple wireless charging circuits 600. The control terminal of the control module 701 is respectively connected to the control terminals of multiple wireless charging circuits 600. The control module 701 is used to control one of the multiple wireless charging circuits 600 to be turned on, and the other wireless charging circuits 600 to be turned off. The wireless charging circuit 600 is used to wirelessly charge a wirelessly connected terminal device.

[0108] Exemplarily, when the wireless charging circuit 600 receives a turn-on signal from the control module 701, the wireless charging circuit 600 turns on and radiates electromagnetic energy into space, thereby wirelessly charging the corresponding terminal device. When the wireless charging circuit 600 receives a turn-off signal from the control module 701, the wireless charging circuit 600 turns off and stops radiating electromagnetic energy into space, thereby stopping wireless charging the corresponding terminal device.

[0109] Fig.13 This is a circuit diagram of a wireless charging module provided in yet another embodiment of the present application.

[0110] like Fig.13As shown, in one embodiment provided by the present application, the wireless charging module 200 includes a control module 701, a stylus charging circuit 2021 and a wireless keyboard charging circuit 2022. The control module 701 includes a power input terminal, a power output terminal and a control terminal. The power output terminal of the control module 701 is respectively connected to the first power terminal of the AC power of the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022, and the power input terminal of the control module 701 is respectively connected to the second power terminal of the AC power of the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022. The control terminal of the control module 701 is respectively connected to the control terminals of multiple stylus charging circuits 2021 and wireless keyboard charging circuits 2022. The control module 701 is used to control one of the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022 to be turned on and the other to be turned off. The stylus charging circuit 2021 is used to wirelessly charge the stylus in the turned-on state, and to stop wirelessly charging the stylus in the turned-off state. The wireless keyboard charging circuit 2022 is used to wirelessly charge the wireless keyboard when in the on state, and to stop wirelessly charging the wireless keyboard when in the off state.

[0111] It should be understood that in the embodiment of the present application, the wireless charging module 200 may include not only the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022, but also other similar wireless charging circuits, such as a watch wireless charging circuit or a headphone wireless charging circuit.

[0112] Exemplarily, the stylus charging circuit 2021 includes a first PMOS transistor Q1, a first capacitor C1, a first coil L1, a second NMOS transistor Q2, a first resistor R1, a second resistor R2, and a second capacitor C2. Among them, the first PMOS transistor Q1 includes a first transistor structure A1 and a first parasitic diode D1. The gate of the first transistor structure A1 is connected to the drain of the second NMOS transistor Q2 through the first resistor R1, the drain of the first transistor structure A1 is connected to the power output end of the control module 701 and the positive electrode of the first parasitic diode D1, the source of the first transistor structure A1 is connected to the negative electrode of the first parasitic diode D1 and the first plate of the first capacitor C1, the second plate of the first capacitor C1 is connected to the first end of the first coil L1, the second end of the first coil L1 is connected to the power input end of the control module 701, the gate of the second NMOS transistor Q2 is connected to the control end of the control module 701, and the source of the second NMOS transistor Q2 is grounded. The second resistor R2 and the second capacitor C2 are both connected between the gate and the source of the first transistor structure A1.

[0113] When the stylus pen 20 is close to the electronic device 10, and the control module 701 obtains that the stylus pen 20 is within a preset range close to the electronic device 10, the control module 701 outputs a stylus pen wireless charging conduction signal and sends it to the gate of the second NMOS transistor Q2 of the stylus pen charging circuit 2021. When the gate of the second NMOS transistor Q2 receives the stylus pen conduction signal (i.e., a high-level signal), the second NMOS transistor Q2 is turned on, thereby pulling down the gate of the first transistor structure A1. When the gate of the first transistor structure A1 receives a low-level signal, the first transistor structure A1 is turned on, thereby radiating electromagnetic energy to the stylus pen 20 through the first transistor structure A1 or the first parasitic diode D1, and the first capacitor C1 and the first inductor L1 to form a resonant circuit, so that the stylus pen charging circuit 2021 performs wireless charging on the stylus pen 20. The first resistor R1 and the second resistor R2 form a voltage divider circuit to adjust the voltage connected between the gate and the source of the first transistor structure A1. The second capacitor C2 is used to stabilize the voltage connected between the gate and the source of the first transistor structure A1.

[0114] When the stylus pen 20 is away from the electronic device 10, and the control module 701 obtains that the stylus pen 20 is away from the preset range of the electronic device 10, the control module 701 outputs a stylus pen wireless charging disconnection signal and sends it to the gate of the second NMOS transistor Q2 of the stylus pen charging circuit 2021. When the gate of the second NMOS transistor Q2 receives the stylus pen disconnection signal (i.e., a low-level signal), the second NMOS transistor Q2 is disconnected, thereby pulling up the gate of the first transistor structure A1. When the gate of the first transistor structure A1 receives a high-level signal, the first transistor structure A1 is disconnected, thereby causing the stylus pen charging circuit 2021 to stop wirelessly charging the stylus pen 20.

[0115] Exemplarily, the wireless keyboard charging circuit 2022 includes a third PMOS tube Q3, a third capacitor C3, a second coil L2, a fourth NMOS tube Q4, a third resistor R3, a fourth resistor R4 and a fourth capacitor C4. Among them, the third PMOS tube Q3 includes a third transistor structure A3 and a second parasitic diode D2. The gate of the third transistor structure A3 is connected to the drain of the fourth NMOS tube Q4 through the third resistor R3, the drain of the third transistor structure A3 is connected to the power output end of the control module 701 and the positive electrode of the second parasitic diode D2, the source of the third transistor structure A3 is connected to the negative electrode of the second parasitic diode D2 and the first plate of the third capacitor C3, the second plate of the third capacitor C3 is connected to the first end of the second coil L2, the second end of the second coil L2 is connected to the power input end of the control module 701, the gate of the fourth NMOS tube Q4 is connected to the control end of the control module 701, and the source of the fourth NMOS tube Q4 is grounded. The fourth resistor R4 and the fourth capacitor C4 are both connected between the gate and the source of the third transistor structure A3.

[0116] When the wireless keyboard 30 is close to the electronic device 10, and the control module 701 obtains that the wireless keyboard 30 is within a preset range close to the electronic device 10, the control module 701 outputs a wireless keyboard wireless charging conduction signal and sends it to the gate of the fourth NMOS transistor Q4 of the wireless charging circuit 703 of the wireless keyboard 30. When the gate of the fourth NMOS transistor Q4 receives the wireless keyboard 30 conduction signal (i.e., a high-level signal), the fourth NMOS transistor Q4 is turned on, thereby pulling down the gate of the third transistor structure A3. When the gate of the third transistor structure A3 receives a low-level signal, the third transistor structure A3 is turned on, thereby radiating electromagnetic energy to the wireless keyboard 30 through the third transistor structure A3 or the second parasitic diode D2, and the third capacitor C3 and the second inductor L2 to form a resonant circuit, so that the wireless keyboard charging circuit 2022 performs wireless charging on the wireless keyboard 30. The third resistor R3 and the fourth resistor R4 form a voltage divider circuit to adjust the voltage connected between the gate and the source of the third transistor structure A3, and the fourth capacitor C4 is used to stabilize the voltage connected between the gate and the source of the third transistor structure A3.

[0117] When the wireless keyboard 30 is far away from the electronic device 10, and the control module 701 obtains that the wireless keyboard 30 is far away from the preset range of the electronic device 10, the control module 701 outputs a wireless keyboard wireless charging disconnection signal and sends it to the gate of the fourth NMOS transistor Q4 of the wireless keyboard charging circuit 2022. When the gate of the fourth NMOS transistor Q4 receives the wireless keyboard disconnection signal (i.e., a low-level signal), the fourth NMOS transistor Q4 is disconnected, thereby pulling up the gate of the third transistor structure A3. When the gate of the third transistor structure A3 receives a high-level signal, the third transistor structure A3 is disconnected, thereby causing the wireless keyboard charging circuit 2022 to stop wirelessly charging the wireless keyboard 30.

[0118] The following is a simulation test of the circuit diagram of the wireless charging module provided in the embodiment of the present application in combination with the simulation waveform diagram and the measured waveform diagram of the wireless charging module.

[0119] Fig.14 This is a simulation waveform diagram of a wireless charging module provided in an embodiment of the present application.

[0120] For example, in one embodiment provided in the present application, Fig.13It can be seen from the simulation of the circuit diagram of the wireless charging module shown in the figure that: the power output end of the control module 701 outputs a stable square wave of 147KHz. After running for 0.2ms, the control module 701 outputs a stylus conduction signal (i.e., a high-level signal) to the second NMOS tube Q2. The second NMOS tube Q2 enters the conduction state according to the stylus conduction signal, thereby lowering the gate voltage of the first PMOS tube Q1. When the first PMOS tube Q1 receives a low-level signal, the first PMOS tube Q1 is turned on, so that the first capacitor C1 and the first coil L1 convert the square wave into electromagnetic energy and radiate it into space, so that the stylus charging circuit 2021 wirelessly charges the stylus 20. It should be noted that at this time, the fourth NMOS tube Q4 is not driven, and the third PMOS tube Q3 and the fourth NMOS tube Q4 are always kept in the disconnected state, so that the wireless keyboard charging circuit 2022 does not wirelessly charge the wireless keyboard 30.

[0121] like Fig.14 As shown, VIN is a stable square wave of 147KHz, Q2-G is the gate signal of the second NMOS tube Q2 in the stylus path, Q3-G is the gate signal of the third PMOS tube Q3 in the wireless keyboard path, VC1 is the voltage across the resonant capacitor of the stylus path (i.e., the first capacitor C1), VC3 is the voltage across the resonant capacitor of the wireless keyboard path (i.e., the third capacitor C3), Ipen is the current of the stylus path, and Ikeyboard is the current of the wireless keyboard path.

[0122] It can be seen from the simulation waveform that during the period from the start to 0.2ms, a 147KHz stable square wave is stably output from the power output end of the control module 701 to the stylus charging circuit 2021 and the wireless keyboard charging circuit 2022. When the stylus charging circuit 2021 receives the 147KHz stable square wave, the 147KHz stable square wave will charge the resonant capacitor (i.e., the first capacitor C1) through the body diode in the first PMOS tube Q1. When the first capacitor C1 is fully charged, the voltage VC1 across the first capacitor C1 maintains the charged voltage, the first PMOS tube Q1 is disconnected, and the current Ipen flowing through the stylus path of the first PMOS tube Q1 is 0. At this time, the gate of the second NMOS tube Q2 has no driving voltage, and the driving signal Q2-G of the stylus path is a low-level signal.

[0123] When the wireless keyboard charging circuit 2022 receives a 147KHz stable square wave, the 147KHz stable square wave will charge the resonant capacitor (i.e., the third capacitor C3) through the body diode in the third PMOS tube Q3. When the third capacitor C3 is fully charged, the voltage VC3 across the third capacitor C3 maintains the charged voltage, the third PMOS tube Q3 is disconnected, and the current Ikeyboard of the wireless keyboard path flowing through the third PMOS tube Q3 path is 0. At this time, the gate of the third PMOS tube Q3 has no driving voltage, and the driving signal Q3-G of the wireless keyboard path is a high-level signal.

[0124] After 0.2ms, the control module 701 inputs a high-level signal to the gate of the second NMOS transistor Q2, i.e., Q2-G is at a high level, thereby turning on the second NMOS transistor Q2, pulling down the gate voltage of the first PMOS transistor Q1, thereby turning on the first PMOS transistor Q1, and further turning on the stylus charging circuit 2021, and wirelessly charging the stylus 20. At this time, the current Ipen in the stylus path begins to change in waveform, and the voltage VC1 across the resonant capacitor (i.e., the first capacitor C1) also begins to change in voltage.

[0125] It should be noted that, in the process of the stylus charging circuit 2021 being turned on and wirelessly charging the stylus 20, the wireless keyboard charging circuit 2022 does not receive an enable signal, so the wireless keyboard path always remains disconnected, the current Ikeyboard of the wireless keyboard path remains at 0, the driving signal Q3-G of the wireless keyboard path remains at a high level, and the resonant capacitor (i.e., the third capacitor C3) has no current discharge, so the voltage VC3 across the third capacitor C3 is stable and maintains the previous voltage level. Therefore, based on the above simulation waveforms, it can be seen that the wireless charging circuit 600 provided in the embodiment of the present application meets the expected design and can realize the conduction and disconnection of the wireless charging path.

[0126] Fig.15 This is a measured waveform diagram of a wireless charging module provided in an embodiment of the present application.

[0127] like Fig.15 As shown, illustratively, in an embodiment provided in the present application, it is possible to Fig.13 The circuit diagram of the wireless charging module shown in FIG. 2 is used for actual verification. The gate signal of the third PMOS transistor Q3 in the wireless keyboard charging circuit 2022 is mos-g-keyboard, the path current of the wireless keyboard charging circuit 2022 is I-mos-s-to-C-keyboard, the gate signal of the first PMOS transistor Q1 in the stylus charging circuit 2021 is mos-g-pen, and the path current of the stylus charging circuit 2021 is I-mos-s-to-C-pen.

[0128] When the wireless charging module 200 uses the stylus charging circuit 2021 to wirelessly charge the stylus 20, the wireless keyboard charging circuit 2022 is in a disconnected state. Fig.15 It can be seen that when the gate of the first PMOS tube Q1 of the stylus charging circuit 2021 receives a driving signal, the gate of the first PMOS tube Q1 is pulled low, so that the first PMOS tube Q1 is turned on, an alternating current passes through the stylus wireless charging path, and the stylus charging circuit 2021 can normally perform wireless charging on the stylus 20. At the same time, since the gate of the third PMOS tube Q3 in the wireless keyboard charging circuit 2022 does not receive a driving signal, the gate of the third PMOS tube Q3 is at a high level, and the third PMOS tube Q3 is in an off state.

[0129] It should be noted that, since the third PMOS tube Q3 is in the off state and no current flows, the right plate voltage of the resonant capacitor (i.e., the third capacitor C3) in the wireless keyboard charging circuit 2022 is equal to the power input terminal voltage of the control module 701, i.e., V 回流 However, at this time, the stylus charging circuit 2021 is wirelessly charging the stylus 20, so the power input voltage V 回流 At the same time, when charging the resonant capacitor (i.e., the third capacitor C3) of the wireless keyboard charging circuit 2022 for the first time, in the absence of a discharge path, the voltage across the third capacitor C3 is stable, i.e., V 回流 Since the voltage across the capacitor cannot change suddenly, the voltage on the left plate of the third capacitor C3 is equal to V 回流 Therefore, the gate-source Vsg of the third PMOS tube Q3 has no voltage difference and will not be turned on, and a periodically changing waveform is presented. Exemplarily, the waveform of the third PMOS tube Q3 can be a square wave that periodically changes within the range of 5.3-10.6V.

[0130] In addition, in the embodiment of the present application, since the wireless charging path can be turned on and off by a switch device and a capacitor, the number of electronic devices used in the wireless charging circuit is effectively reduced, the cost of the wireless charging circuit is reduced, and the volume of the wireless charging circuit is reduced. It should be noted that when the wireless charging module 200 includes at least two wireless charging circuits, the wireless charging module also includes a first packaging structure and a second packaging structure, one of the first switch devices in the two wireless charging circuits is packaged in the first packaging structure, and the other of the first switch devices in the two wireless charging circuits is packaged in the second packaging structure. Alternatively, the wireless charging module also includes a third packaging structure, and the first switch devices in the two wireless charging circuits are both packaged in the third packaging structure. In other words, the first switch device in each wireless charging circuit can be packaged separately and connected to the wireless charging circuit as an independent device, or every two first switch devices can be packaged together and connected to their respective wireless charging circuits. As shown in Table 1 below, Figure 5 Two PMOS tubes and Fig.13 The cost comparison table of using a PMOS tube to realize the conduction and shutdown of the wireless charging path is shown in the figure, where X1 is the cost of a single PMOS tube and X2 is the cost of a dual PMOS tube.

[0131] Table 1 Cost comparison table

[0132]

[0133] In combination with the above Table 1, it can be seen that when the wireless charging module 200 includes two wireless charging circuits, the single PMOS tube solution provided in the embodiment of the present application can save the cost of two separate PMOS tubes or one dual PMOS tube, which is more suitable for the development trend of miniaturization and low cost of electronic equipment.

[0134] Combination of the above Figures 1 to 15 , describes the structural schematic diagrams, circuit diagrams, waveform diagrams, and applicable scenarios of several embodiments provided in this application. Fig.16 , describes in detail the hardware system and chip system of the electronic device to which the present application is applicable. It should be understood that the hardware system and chip system in the embodiments of the present application can execute the various structural schematic diagrams or circuit diagrams of the aforementioned embodiments of the present application, that is, the specific working processes of the following various products can refer to the corresponding working processes in the aforementioned embodiments.

[0135] Fig.16 A hardware system of a terminal device provided in an embodiment of the present application.

[0136] like Fig.16 As shown, for example, in the embodiment of the present application, the electronic device 10 may be Figure 1 and Figure 2 The tablet computer shown can also be a mobile phone, a smart screen, a wearable electronic device, an in-vehicle electronic device, an augmented reality device, a virtual reality (VR) device, a laptop, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), and other terminal devices with wireless charging functions. The embodiment of the present application does not impose any restrictions on the specific type of the electronic device 10. The electronic device 10 provided in the embodiment of the present application can realize the conduction and disconnection of the wireless charging path through a switch device and a capacitor, thereby effectively reducing the number of electronic devices applied to the wireless charging circuit, reducing the cost of the wireless charging circuit, and reducing the volume of the wireless charging circuit, so it is more suitable for the development trend of miniaturization and low cost of electronic devices.

[0137] The electronic device 10 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 300, a first antenna 1, a second antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a magnetic sensor 180A, which is the Hall sensor mentioned above.

[0138] It should be noted that the structure shown in the hardware system does not constitute a specific limitation on the electronic device. In other embodiments of the present application, the electronic device may include more or fewer components than those shown in the hardware system, or the electronic device may include a combination of some of the components shown in the hardware system, or the electronic device may include sub-components of some of the components shown in the hardware system. The components shown in the hardware system may be implemented in hardware, software, or a combination of software and hardware.

[0139] The processor 110 may include one or more processing units. For example, the processor 110 may include at least one of the following processing units: an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and a neural-network processing unit (NPU). Different processing units may be independent devices or integrated devices. The controller may generate an operation control signal according to the instruction opcode and the timing signal to complete the control of fetching and executing instructions.

[0140] The processor 110 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in the processor 110 is a cache memory. The memory may store instructions or data that the processor 110 has just used or cyclically used. If the processor 110 needs to use the instruction or data again, it may be directly called from the memory. This avoids repeated access, reduces the waiting time of the processor 110, and thus improves the efficiency of the system.

[0141] The connection relationship between the modules shown in the hardware system is only a schematic illustration and does not constitute a limitation on the connection relationship between the modules of the electronic device. Optionally, the modules of the electronic device may also adopt a combination of multiple connection modes in the above embodiments.

[0142] The charging management module 140 is used to receive power from the charger or transmit power to other electronic devices. While charging the battery 300, the charging management module 140 can also power the electronic device through the power management module 141, and can also wirelessly charge other electronic devices close to the electronic device 10 through the internal wireless charging module. The power management module 141 is used to connect the battery 300, the charging management module 140 and the processor 110. The power management module 141 receives input from the battery 300 and / or the charging management module 140, and provides power to the processor 110, the internal memory 121, the display 194, the camera 193 and the wireless communication module 160. The power management module 141 can also be used to monitor parameters such as battery capacity, battery cycle number and battery health status (e.g., leakage, impedance). Optionally, the power management module 141 can be set in the processor 110, or the power management module 141 and the charging management module 140 can be set in the same device.

[0143] For example, in the embodiment of the present application, the electronic device 10 supports the stylus 20 or the wireless keyboard 30 to be magnetically adsorbed to the preset area of ​​the electronic device 10. When the magnetic sensor 180A detects that the stylus 20 or the wireless keyboard 30 is adsorbed to the electronic device 10, the electronic device can determine the in-place state of the stylus 20 or the wireless keyboard 30 through the processor 110. When the stylus 20 or the wireless keyboard 30 is in the in-place state, the processor 110 controls the charging management module 140 (for example, a charging chip) to wirelessly charge the stylus 20 or the wireless keyboard 30. At the same time, the processor 110 controls the charging management module 140 to continue or stop charging the stylus 20 or the wireless keyboard 30 according to whether the magnetic sensor 180A reports the event of the stylus 20 or the wireless keyboard 30 being removed and whether the charging management module 140 receives an interruption event of charging stopping.

[0144] It should be understood that the electronic device 10 can only wirelessly charge one terminal device at a time, the stylus pen 20 or the wireless keyboard 30. That is, when the electronic device 10 wirelessly charges the stylus pen 20, the electronic device 10 only charges the stylus pen 20, and does not wirelessly charge the wireless keyboard 30 or other terminal devices. When the electronic device wirelessly charges the wireless keyboard 30, the electronic device 10 only charges the wireless keyboard 30, and does not wirelessly charge the stylus pen 20 or other terminal devices.

[0145] The wireless communication function of the electronic device can be implemented by devices such as antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modulation and demodulation processor, and baseband processor. Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the electronic device can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve the utilization rate of the antenna.

[0146] The mobile communication module 150 can provide a wireless communication solution applied to the electronic device, such as at least one of the following solutions: a second generation (2G) mobile communication solution, a third generation (3G) mobile communication solution, a fourth generation (5G) mobile communication solution, and a fifth generation (5G) mobile communication solution.

[0147] The modem processor may include a modulator and a demodulator. The modulator is used to modulate the low-frequency baseband signal to be sent into a medium-high frequency signal. The demodulator is used to demodulate the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing. After the low-frequency baseband signal is processed by the baseband processor, it is passed to the application processor. The application processor outputs a sound signal through an audio device (e.g., a speaker 170A, a receiver 170B), or displays an image or video through a display screen 194. In some embodiments, the modem processor may be an independent device. In other embodiments, the modem processor may be independent of the processor 110 and may be set in the same device as the mobile communication module 150 or other functional modules.

[0148] Similar to the mobile communication module 150, the wireless communication module 160 can also provide wireless communication solutions for application in electronic devices, such as at least one of the following solutions: wireless local area networks (WLAN), Bluetooth (BT), Bluetooth low energy (BLE), ultra wide band (UWB), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared (IR) technology, etc.

[0149] In some embodiments, the antenna 1 of the electronic device is coupled to the mobile communication module 150, and the antenna 2 of the electronic device is coupled to the wireless communication module 160, so that the electronic device can communicate with the network and other electronic devices through wireless communication technology.

[0150] The external memory interface 120 can be used to connect an external memory card, such as a secure digital (SD) card, to expand the storage capacity of the electronic device. The external memory card communicates with the processor 110 through the external memory interface 120 to implement a data storage function. For example, files such as music and videos can be stored in the external memory card.

[0151] The internal memory 121 may be used to store computer executable program codes, which include instructions. The internal memory 121 may include a program storage area and a data storage area.

[0152] The key 190 includes a power key and a volume key. The key 190 can be a mechanical key or a touch key. The electronic device can receive a key input signal and implement a function related to the case input signal.

[0153] Exemplarily, an embodiment of the present application also provides an electronic device, including a wireless charging circuit or a wireless charging module as described above, the electronic device also includes a battery, the battery is used to store electrical energy, the wireless charging circuit or the wireless charging module is used to convert the electrical energy of the battery into electromagnetic energy and radiate it into space, so as to be able to wirelessly charge other terminal devices (such as a stylus or a wireless keyboard, etc.). The wireless charging module includes the wireless charging circuit described above. It should be understood that the wireless charging circuit of the electronic device provided in the embodiment of the present application can realize the conduction and disconnection of the wireless charging path only through a switching device and a capacitor, thereby effectively reducing the number of electronic devices applied to the wireless charging circuit, reducing the cost of the wireless charging circuit, and reducing the size of the wireless charging circuit, so it is more suitable for the development trend of miniaturization and low cost of electronic equipment.

[0154] It should be understood that the above is only an example of the structure of the electronic device 10, and the electronic device 10 may also include other subsystems or devices, which can be configured and modified as needed, and the embodiments of the present application do not impose any limitations on this.

[0155] The beneficial effects that can be achieved by the electronic device provided in the above-mentioned embodiment of the present application can refer to the beneficial effects corresponding to the modules provided above, which will not be repeated here.

[0156] It should be understood that the above is only to help those skilled in the art to better understand the embodiments of the present application, rather than to limit the scope of the embodiments of the present application. According to the above examples given, those skilled in the art can obviously make various equivalent modifications or changes. For example, some steps in each embodiment of the above detection method may be unnecessary, or some steps may be newly added. Or a combination of any two or any multiple embodiments of the above. Such modifications, changes or combined solutions also fall within the scope of the embodiments of the present application. In addition, the coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0157] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0158] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0159] It should also be understood that the above description of the embodiments of the present application focuses on emphasizing the differences between the various embodiments. The same or similar points that are not mentioned can be referenced to each other. For the sake of brevity, they will not be repeated here.

[0160] It should also be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0161] It should also be understood that in the embodiments of the present application, "pre-setting" and "pre-definition" can be achieved by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in a device (for example, including an electronic device), and the present application does not limit its specific implementation method.

[0162] It should also be understood that the division of the methods, situations, categories and embodiments in the embodiments of the present application is only for the convenience of description and should not constitute a special limitation. The features of various methods, categories, situations and embodiments can be combined without contradiction.

[0163] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0164] Finally, it should be noted that the above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims. In short, the above is only a preferred embodiment of the technical solution of the present application, and is not used to limit the protection scope of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A wireless charging circuit, characterized in that: The device comprises a first switch device, a first unidirectional device, a first capacitor and a first coil, wherein a first end of the first switch device is connected to a first power supply terminal of an AC power source and a first end of the first unidirectional device, a second end of the first switch device is connected to a first plate of the first capacitor and a second end of the first unidirectional device, a second plate of the first capacitor is connected to a first end of the first coil, and a second end of the first coil is connected to a second power supply terminal of the AC power source; When the first switch device is in the on state and the AC power output by the AC power source is in a positive half cycle, the AC power flows from the first power supply terminal of the AC power source to the second power supply terminal of the AC power source through the first unidirectional device; when the first switch device is in the on state and the AC power output by the AC power source is in a negative half cycle, the AC power flows from the second power supply terminal of the AC power source to the first power supply terminal of the AC power source through the first switch device; at the same time, electromagnetic energy is radiated into space through the first capacitor and the first coil; When the first switching device is in the off state and the AC power output by the AC power supply is in the positive half cycle, the AC power charges the first capacitor to a preset voltage through the first unidirectional device; when the first switching device is in the off state and the AC power output by the AC power supply is in the negative half cycle, the first unidirectional device is reversely cut off and stops radiating electromagnetic energy into the space.

2. The wireless charging circuit according to claim 1, characterized in that: The wireless charging circuit includes a first PMOSFET, the first PMOSFET includes a transistor structure and a parasitic diode, the first switching device is the transistor structure, and the first unidirectional device is the parasitic diode.

3. The wireless charging circuit according to claim 1, characterized in that: The wireless charging circuit also includes a second switch device, a first end of the second switch device is connected to the control end of the first switch device, and a second end of the second switch device is grounded; when the second switch device is in a conducting state, the first switch device is also in a conducting state.

4. The wireless charging circuit according to claim 3, characterized in that: The second switch device includes a second NMOSFET, a drain of the second NMOSFET is connected to the control terminal of the first switch device, and a source of the second NMOSFET is grounded.

5. The wireless charging circuit according to any one of claims 1 to 4, characterized in that: The wireless charging circuit also includes a first resistor and a second resistor, wherein the first end of the first resistor and the first end of the second resistor are both connected to the control end of the first switch device, and the second end of the first resistor is connected to a control signal; and the second end of the second resistor is connected to the second end of the first switch device.

6. The wireless charging circuit according to any one of claims 1 to 4, characterized in that: The wireless charging circuit further includes a second capacitor, a first end of the second capacitor is connected to the control end of the first switch device, and a second end of the second capacitor is connected to the second end of the first switch device.

7. A wireless charging module, characterized in that: It comprises a control module and a plurality of wireless charging circuits as described in any one of claims 1 to 6; the control module is respectively connected to the plurality of wireless charging circuits; the control module is used to control one of the plurality of wireless charging circuits to be turned on; when the wireless charging circuit is in the turned-on state, it is used to radiate electromagnetic energy into the space.

8. The wireless charging module according to claim 7, characterized in that: The wireless charging circuit includes at least one of a stylus charging circuit and a wireless keyboard charging circuit, and only one of the stylus charging circuit and the wireless keyboard charging circuit is turned on at a time.

9. The wireless charging module according to claim 7, wherein: The wireless charging module also includes a first packaging structure and a second packaging structure, one of the first switching devices in the two wireless charging circuits is packaged in the first packaging structure, and the other of the first switching devices in the two wireless charging circuits is packaged in the second packaging structure.

10. The wireless charging module according to claim 7, wherein: The wireless charging module also includes a third packaging structure, and the first switching devices in the two wireless charging circuits are both packaged in the third packaging structure.

11. An electronic device, characterized in that: The electronic device comprises a wireless charging circuit as described in any one of claims 1 to 6 or a wireless charging module as described in any one of claims 7 to 10, and the electronic device also comprises a battery; the wireless charging circuit and the wireless charging module are both used to convert the electrical energy of the battery into electromagnetic energy and radiate it into the space.

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