Single-coil wireless charging circuit compatible with multiple devices and control method

Abstract

The invention relates to a single-coil wireless charging circuit compatible with multiple devices and a control method. The charging circuit comprises a main control module and a wireless charging power control module. A first control signal output end of the main control module is connected with a control signal input end of the charging and discharging management unit, and the main control module identifies a corresponding equipment type through a wireless charging standard protocol; the power input end of the wireless charging power control module is connected with the wireless charging source output end of the charging and discharging management unit, and the control signal input end of the wireless charging power control module is connected with the second control signal output end of the main control module so as to switch to the corresponding resonant capacitor bank according to the equipment type. And outputting wireless charging power parameters adaptive to different types of equipment. Dynamic bus adjustment, equipment protocol identification and resonance parameter switching means are added on a single-coil architecture, so that the wireless charging system is converted from multi-hardware stacked adaptation to single-hardware intelligent adaptation, and the functions of miniaturization, low cost, high efficiency and high compatibility are realized.

Description

Technical Field

[0001] This invention relates to the technical field of a single-coil wireless charging circuit compatible with multiple devices, and in particular to a single-coil wireless charging circuit and control method compatible with multiple devices. Background Technology

[0002] Currently, with the widespread use of portable devices such as smartphones, smartwatches, and wireless earphones, the demand for magnetic wireless power banks that can simultaneously support multiple devices is constantly increasing. Existing wireless power banks typically employ a multi-coil structure, meaning that each device has its own independent transmitting coil and corresponding resonant drive circuit. While this can cover the charging needs of multiple devices, multiple coils and their associated drive circuits occupy a significant amount of space, increasing the overall size of the power bank, complicating its structure, and raising material costs. This hinders the miniaturization and lightweight design of the device. Furthermore, the close proximity of multiple coils during operation can easily lead to electromagnetic coupling interference, causing resonance misalignment, reduced efficiency, and localized overheating, thus affecting charging stability and safety. Summary of the Invention

[0003] To address the problems of existing multi-coil wireless charging solutions being bulky, costly, subject to severe electromagnetic interference, and difficult to achieve efficient compatibility with multiple devices, this application provides a single-coil wireless charging circuit and control method compatible with multiple devices.

[0004] A single-coil wireless charging circuit compatible with multiple devices, the single-coil wireless charging circuit compatible with multiple devices includes a power management module, a main control module and a wireless charging power control module; The power management module includes a charge / discharge management unit and a device connection terminal. The device connection terminal is used to connect to an external device and is connected to the power connection terminal of the charge / discharge management unit. The charge / discharge management unit identifies the power supply attributes of the external device and switches to the corresponding working direction to output corresponding power when discharging the external device, or to charge the lithium battery when charging. The first control signal output terminal of the main control module is connected to the control signal input terminal of the charge and discharge management unit to configure the bus voltage output parameters of the power connection terminal and the wireless charging power output terminal in the charge and discharge management unit. After the wireless charging power control module receives the bus voltage output according to the bus voltage output parameters, the main control module communicates bidirectionally with the external device through the wireless charging standard protocol to identify the corresponding device type. The power input terminal of the wireless charging power control module is connected to the wireless charging power output terminal of the charging and discharging management unit, and the control signal input terminal of the wireless charging power control module is connected to the second control signal output terminal of the main control module, so as to switch to the corresponding resonant capacitor group according to the device type, and then output wireless charging power parameters adapted to different types of devices.

[0005] By adopting the above technical solution, the single-coil wireless charging circuit, through the collaboration of the power management module, the main control module and the wireless charging power control module, enables the charging and discharging direction to automatically switch according to the power supply attributes of the external device, and dynamically adjusts the wireless charging power parameters after identifying different device types, so as to achieve accurate adaptation charging of a single coil for multiple types of devices, thereby significantly reducing the complexity of the hardware structure, reducing the electromagnetic interference caused by multiple coils, and improving the overall energy efficiency and compatibility.

[0006] Preferably, the charge / discharge management unit includes a bidirectional power management chip U1, MOSFETs Q2, Q3, Q6, Q7, and an inductor L1. The first half-bridge conducting terminal of the bidirectional power management chip U1 is connected to the first terminal of the inductor L1, and the second half-bridge conducting terminal of the bidirectional power management chip U1 is connected to the second terminal of the inductor L1. The first conducting terminal of MOSFET Q2 is connected to a device connection terminal, and the second conducting terminal of MOSFET Q2 is connected to a common node between the first half-bridge conducting terminal of the bidirectional power management chip U1 and the first terminal of the inductor L1. The controlled terminal of MOSFET Q2 is connected to the first left half-bridge enable driving terminal of the bidirectional power management chip U1. The first conducting terminal of MOSFET Q6 is grounded, and the second conducting terminal of MOSFET Q7 is connected to the first half-bridge enabling terminal of the bidirectional power management chip U1. On a common node between the half-bridge conduction terminal and the first terminal of the inductor L1, the controlled terminal of the MOSFET Q6 is connected to the second left half-bridge enable drive terminal of the bidirectional power management chip U1, the first conduction terminal of the MOSFET Q3 is connected to the battery, the second conduction terminal of the MOSFET Q3 is connected to a common node between the second half-bridge conduction terminal of the bidirectional power management chip U1 and the second terminal of the inductor L1, the controlled terminal of the MOSFET Q3 is connected to the first right half-bridge enable drive terminal of the bidirectional power management chip U1, the first conduction terminal of the MOSFET Q7 is grounded, the second conduction terminal of the MOSFET Q7 is connected to a common node between the second half-bridge conduction terminal of the bidirectional power management chip U1 and the second terminal of the inductor L1, and the controlled terminal of the MOSFET Q7 is connected to the second right half-bridge enable drive terminal of the bidirectional power management chip U1.

[0007] By adopting the above technical solution, the charging and discharging management unit forms a complete buck-boost power path with a bidirectional power management chip, multiple MOSFETs and inductors, enabling the system to flexibly switch the current direction under different power supply modes, and realize controllable power flow between the USB port, C port and battery under the control of the main control signal, thereby ensuring the stability, efficiency and safety of the charging and discharging process.

[0008] Preferably, the device connection terminals include terminal USB1 and terminal C2+, and the charge / discharge management unit further includes MOSFET Q1 and MOSFET Q8. The first conducting terminal of MOSFET Q1 is connected to terminal USB1, the first conducting terminal of MOSFET Q8 is connected to terminal C2+, the second conducting terminals of MOSFET Q1 and MOSFET Q8 are merged into the same node to be connected to the first conducting terminal of MOSFET Q2, the controlled terminal of MOSFET Q1 is connected to the first enable signal output terminal of the charge / discharge management unit, and the controlled terminal of MOSFET Q8 is connected to the second enable signal output terminal of the charge / discharge management unit.

[0009] By adopting the above technical solution, the device connection terminal adds a MOS transistor switching structure, enabling the USB1 and C2+ ports to automatically select ports under the enable signal of the main control module. This ensures that external devices can obtain the correct power supply path under different connection methods, improving interface compatibility and multi-port adaptive capability.

[0010] Preferably, the wireless charging power control module includes a wireless charging transmitter control chip U4, a MOSFET Q5, a capacitor C43, a controllable capacitor bank, and a wireless charging coil LP1. The power input terminal of the wireless charging transmitter control chip U4 is connected to the wireless charging power output terminal of the charging and discharging management unit. The first power output terminal of the wireless charging transmitter control chip U4 is connected to the first terminal of the wireless charging coil LP1. The second power output terminal of the wireless charging transmitter control chip U4 is connected to the first conducting terminal of the MOSFET Q5 and the first terminal of the capacitor C43. The second conducting terminal of the MOSFET Q5 is connected to the first terminal of the controllable capacitor bank. The second terminal of the controllable capacitor bank and the second terminal of the capacitor C43 are combined into a sampling node. The sampling node is connected to the second terminal of the wireless charging coil LP1. The controlled terminal of the MOSFET Q5 is connected to the second power output terminal of the wireless charging transmitter control chip U4.

[0011] By adopting the above technical solution, the wireless charging power control module uses a resonant network composed of a wireless charging transmitter control chip, a MOS transistor, a capacitor bank, and a transmitter coil. This enables the transmitter to adjust the resonant parameters and establish a stable magnetic field coupling path according to the control signal of the main control module, thereby achieving reliable single-coil wireless energy output and improving the stability and adaptability of wireless charging power.

[0012] Preferably, the wireless charging power control module further includes a resonant capacitor switching drive unit, which includes a bipolar complementary transistor array Q4. The bipolar complementary transistor array Q4 includes a first switch, a second switch, a first resistor, and a second resistor. The first conducting terminal of the first switch and the first terminal of the first resistor are both connected to the second power output terminal of the wireless charging transmitter control chip U4. The second conducting terminal of the first switch and the first terminal of the first resistor are both connected to the controlled terminal of the MOS transistor Q5. The second terminal of the first resistor is connected to the first terminal of the second resistor. The second terminal of the second resistor is connected to the first conducting terminal of the second switch. The second conducting terminal of the second switch is grounded. The common node between the second terminal of the first resistor and the first terminal of the second resistor is connected to the controlled terminal of the first switch. The controlled terminal of the second switch is connected to the transmitter start / stop signal output terminal of the main control module.

[0013] By adopting the above technical solution, the resonant capacitor switching drive unit rapidly drives the controlled terminal of the MOS transistor through a bipolar complementary transistor array, enabling the controllable capacitor bank to achieve high-speed switching between different device types, thereby improving the resonant frequency conversion speed, reducing energy loss during the switching process, and ensuring the continuity and stability of wireless charging during dynamic adjustment.

[0014] Preferably, the wireless charging power control module further includes a full-bridge high-side input switch Q12, which is composed of two MOSFETs connected in series. The first conducting terminal of the full-bridge high-side input switch Q12 is connected to the wireless charging power output terminal of the charging and discharging management unit, and the second conducting terminal of the full-bridge high-side input switch Q12 is connected to the power input terminal of the wireless charging transmitter control chip U4. The controlled terminals of the two MOSFETs in the full-bridge high-side input switch Q12 are connected to the bus voltage start / stop signal output terminal of the bidirectional power management chip U1.

[0015] By adopting the above technical solution, the full-bridge high-side input switch structure realizes the overall start-stop control of the wireless charging power source input through series MOS transistors, so that the wireless charging transmitter control chip is powered on only when wireless power is needed, avoiding standby loss and ineffective heat generation caused by the transmitter being kept in a powered state for a long time, thereby improving system energy efficiency and operational safety.

[0016] Preferably, the wireless charging power control module further includes MOSFET Q13, MOSFET Q9, and diode D1. The first conducting terminal of MOSFET Q13 is connected to the battery, the second conducting terminal of MOSFET Q13 is connected to the anode terminal of diode D1, the cathode terminal of diode D1 is connected to the power input terminal of the wireless charging transmitter control chip U4, the controlled terminal of MOSFET Q13 is connected to the first conducting terminal of MOSFET Q9, the second conducting terminal of MOSFET Q9 is grounded, and the controlled terminal of MOSFET Q9 is connected to the battery voltage start / stop signal output terminal of the bidirectional power management chip U1.

[0017] By adopting the above technical solution, the additional battery input path composed of the MOS transistor and diode enables the battery to provide emergency or compensation power to the wireless charging transmitter chip under specific start / stop signals. This ensures that the wireless charging transmitter can maintain continuous power supply even when the power bank's input power is unstable or fluctuates transiently, thereby improving the system's reliability and anti-interference capability.

[0018] Preferably, the single-coil wireless charging circuit compatible with multiple devices further includes a protection module. The protection module includes a master control protection chip U2, a MOSFET Q10, and a MOSFET Q11. The MOSFETs Q10 and Q11 are connected in series and form a corresponding power output path with the battery. The controlled terminal of the MOSFET Q10 is connected to the first protection output terminal of the master control protection chip U2, the controlled terminal of the MOSFET Q11 is connected to the second protection output terminal of the master control protection chip U2, the first output node of the battery is connected to the first over-discharge detection terminal of the master control protection chip U2, and the second output node of the battery is connected to the second over-discharge detection terminal of the master control protection chip U2.

[0019] By adopting the above technical solution, the protection module uses a back-to-back switch structure composed of a main control protection chip and dual MOS transistors to ensure that the charging current and discharging current of the battery both pass through a unified and controllable path. When overcharging, over-discharging, or abnormal current is detected, the positive terminal of the battery can be quickly disconnected, thereby effectively protecting the battery safety and preventing system overload damage.

[0020] Preferably, the protection module further includes a single-unit protection chip UT1, a single-unit protection chip UT2, a MOSFET QS1, and a MOSFET QS2. The first conducting terminal of the MOSFET QS1 is connected to the first output node. The second conducting terminal of the MOSFET QS1 is connected to the first conducting terminal of the MOSFET QS2. The second conducting terminal of the MOSFET QS2 is connected to the MOSFET Q11. The common node between the second conducting terminal of the MOSFET QS1 and the first conducting terminal of the MOSFET QS2 is connected to the second output node and the detection input terminal of the single-unit protection chip UT1, respectively. The enable output terminal of the single-unit protection chip UT1 is connected to the controlled terminal of the MOSFET QS1. The common node between the second conducting terminal of the MOSFET QS2 and the MOSFET Q11 is connected to the detection input terminal of the single-unit protection chip UT2. The enable output terminal of the single-unit protection chip UT2 is connected to the controlled terminal of the MOSFET QS2.

[0021] By adopting the above technical solution, the multi-level protection architecture formed by the single-cell protection chip and the MOS transistor connected in series can independently monitor and control the voltage of each single cell in the battery pack. When an abnormal voltage occurs, the current path of the corresponding cell is cut off individually, thereby further improving the accuracy and safety level of battery management and avoiding overall battery failure caused by single-cell imbalance.

[0022] A control method for a multi-device compatible single-coil wireless charging circuit, comprising: Obtain the power supply attributes of the external device, and switch to either discharge mode or charging mode based on the power supply attributes; When in discharge mode and the discharge mode is wireless charging working mode, configure the corresponding bus voltage output parameters, and power on the external device through the bus voltage generated by the bus voltage output parameters; Based on the wireless charging standard protocol, it communicates bidirectionally with external devices to identify the device type of the external device. Based on the device type, determine the corresponding wireless charging power parameters; The wireless charging power parameters are switched to the corresponding resonant capacitor group, thereby driving a single transmitting coil to output the corresponding wireless power to an external device to achieve wireless charging.

[0023] By adopting the above technical solution, the control method determines the working mode by identifying power supply attributes, configures bus voltage parameters, identifies device types based on wireless charging protocols, and switches resonant capacitor banks accordingly, thereby realizing adaptive wireless charging of multiple devices by a single coil. This enables the system to automatically select the optimal power output strategy when different devices are connected, thereby improving wireless charging efficiency, compatibility, and user experience.

[0024] In summary, this application includes at least one of the following beneficial technical effects: This application reorganizes the traditional multi-coil wireless charging architecture into a single-coil dynamic adaptation system composed of a power management module, a main control module, and a wireless charging power control module. It constructs a comprehensive control method capable of automatically identifying device characteristics at the hardware level and switching parameters in real time within the resonant network. The power management module automatically determines the power supply direction and outputs a stable bus voltage when different devices are connected. The main control module completes the handshake and type identification with external devices based on the wireless charging protocol, and then sends corresponding control signals to the wireless charging power control module based on the identification results. This causes the module to automatically switch the resonant capacitor bank and generate resonant conditions adapted to the power requirements of different devices. This allows a single transmitting coil to achieve adaptive wireless charging for different loads such as mobile phones, headphones, and watches. This avoids the problems of bulkiness, complex wiring, and high material costs associated with multi-coil solutions, and completely eliminates coupling interference and heat generation risks between multiple coils, achieving higher system energy efficiency, a simpler hardware architecture, and stronger device compatibility. By adding dynamic bus adjustment, device protocol identification, and resonant parameter switching to the single-coil architecture, the wireless charging system is transformed from multi-hardware stacking adaptation to single-hardware intelligent adaptation, thereby achieving miniaturization, low cost, high efficiency, and high compatibility. Attached Figure Description

[0025] Figure 1 This is a flowchart of a single-coil wireless charging circuit compatible with multiple devices according to one embodiment of this application.

[0026] Figure 2 This is a partial circuit diagram of the charge / discharge management unit in a multi-device compatible single-coil wireless charging circuit according to one embodiment of this application; Figure 3 This is a partial circuit diagram of the device connection terminals in a single-coil wireless charging circuit compatible with multiple devices according to one embodiment of this application; Figure 4 This is a partial circuit structure diagram of the main control module in a single-coil wireless charging circuit compatible with multiple devices according to one embodiment of this application; Figure 5 This is a partial circuit diagram of the wireless charging power control module in a multi-device compatible single-coil wireless charging circuit according to one embodiment of this application. Figure 1 ; Figure 6 This is a partial circuit diagram of the wireless charging power control module in a multi-device compatible single-coil wireless charging circuit according to one embodiment of this application. Figure 2 ; Figure 7This is a partial circuit structure diagram of the protection module in a single-coil wireless charging circuit compatible with multiple devices according to one embodiment of this application; Figure 8 This is a flowchart of a control method for a single-coil wireless charging circuit compatible with multiple devices, according to one embodiment of this application. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the accompanying drawings.

[0028] In one embodiment, such as Figures 1-7 As shown, this application discloses a single-coil wireless charging circuit compatible with multiple devices. The single-coil wireless charging circuit compatible with multiple devices includes a power management module, a main control module, and a wireless charging power control module. The power management module includes a charge / discharge management unit and a device connection terminal. The device connection terminal is used to connect to external devices and is connected to the power connection terminal of the charge / discharge management unit. The charge / discharge management unit identifies the power supply attributes of the external devices and switches to the corresponding working direction to output the corresponding power when discharging the external devices or to charge the lithium battery when charging. The first control signal output terminal of the main control module is connected to the control signal input terminal of the charge and discharge management unit to configure the bus voltage output parameters of the power connection terminal and the wireless charging power output terminal in the charge and discharge management unit. After the wireless charging power control module receives the bus voltage output according to the bus voltage output parameters, the main control module communicates bidirectionally with the external device through the wireless charging standard protocol to identify the corresponding device type. The power input terminal of the wireless charging power control module is connected to the wireless charging power output terminal of the charging and discharging management unit, and the control signal input terminal of the wireless charging power control module is connected to the second control signal output terminal of the main control module, so as to switch to the corresponding resonant capacitor group according to the device type, and then output wireless charging power parameters adapted to different types of devices.

[0029] In this embodiment, the multi-device compatible single-coil wireless charging circuit comprises an integrated power supply and wireless transmission architecture consisting of a power management module, a main control module, and a wireless charging power control module. The components are connected according to predetermined power flow and signal control logic. The power management module internally houses a charge / discharge management unit and establishes power and communication paths with external electronic devices via device connection terminals. In terms of hardware connection, the device connection terminals are directly connected to the input node of the charge / discharge management unit, enabling the power management module to identify the power supply attribute of external devices upon connection. The charge / discharge management unit detects the port power supply direction, voltage level, and message protocol signals to determine whether the external device is in a charging state requiring power to the circuit or a discharging state requiring wireless or wired power from the circuit, and switches the internal power path direction accordingly. Through this connection, the charge / discharge management unit can dynamically adjust the current direction between battery charging and external device discharging, while ensuring the stability of the bus between the battery, power input terminal, and wireless transmitter.

[0030] The main control module's first control signal output terminal is directly connected to the charge / discharge management unit's control signal input terminal. This connection allows the main control module to send bus voltage configuration commands to the charge / discharge management unit. In the initial stage after peripheral connection, the main control module sets the required bus voltage output parameters for the wireless transmitter based on the current operating mode and wireless charging standard protocol requirements. The charge / discharge management unit then generates the bus voltage to power the wireless charging power control module based on these parameters using its own power switching structure. This connection ensures that the wireless charging transmitter module can obtain a suitable and stable input voltage for different device types, thus providing the prerequisites for subsequent resonant configuration and power output.

[0031] The power input terminal of the wireless charging power control module is directly connected to the wireless charging power output terminal of the charging and discharging management unit, enabling the bus voltage regulated by the power management module to be transmitted losslessly to the transmitting chip and resonant network. The second control signal output terminal of the main control module is connected to the control signal input terminal of the wireless charging power control module. This connection is used by the main control module to send resonant parameter configuration commands to the wireless charging transmitter control link after identifying the external device type, achieving rapid switching between controllable capacitor banks and fixed resonant capacitors. After receiving the second control signal, the wireless charging power control module drives internal controllable switches, MOSFETs, or transistor arrays to switch different capacitor branches, changing the equivalent capacitance and resonant frequency of the resonant network, thereby creating wireless power output conditions suitable for different devices such as mobile phones, headphones, and watches. This module further outputs the adjusted resonant energy through a single transmitting coil, achieving magnetic field coupling power supply to external devices.

[0032] The main control module maintains bidirectional information exchange with both the charge / discharge management unit and the wireless charging power control module. Through unified scheduling of power supply direction, bus voltage, capacitor combination, and peripheral type, it achieves adaptive control of multi-device wireless charging under a single-coil architecture. The power management module ensures stable switching between power input and output, the main control module performs device identification and power strategy formulation, and the wireless charging power control module completes dynamic matching of resonant parameters and magnetic field energy output. All structural components form a complete closed loop through power paths and control signal paths, enabling a single coil to be compatible with the wireless charging needs of multiple devices without the need for additional transmitting coils, reducing the space occupation and electromagnetic interference problems caused by traditional multi-coil layouts.

[0033] Furthermore, such as Figure 2 As shown, the charge / discharge management unit includes a bidirectional power management chip U1, MOSFETs Q2, Q3, Q6, and Q7, and an inductor L1. The first half-bridge conducting terminal of the bidirectional power management chip U1 is connected to the first terminal of inductor L1, and the second half-bridge conducting terminal of the bidirectional power management chip U1 is connected to the second terminal of inductor L1. The first conducting terminal of MOSFET Q2 is connected to the device connection terminal, and the second conducting terminal of MOSFET Q2 is connected to a common node between the first half-bridge conducting terminal of the bidirectional power management chip U1 and the first terminal of inductor L1. The controlled terminal of MOSFET Q2 is connected to the first left half-bridge enable driving terminal of the bidirectional power management chip U1. The first conducting terminal of MOSFET Q6 is grounded, and the second conducting terminal of MOSFET Q6 is connected to the first half-bridge enabling terminal of the bidirectional power management chip U1. At a common node between the conducting half-bridge terminal and the first terminal of inductor L1, the controlled terminal of MOSFET Q6 is connected to the enable / drive terminal of the second left half-bridge of bidirectional power management chip U1. The first conducting terminal of MOSFET Q3 is connected to the battery. The second conducting terminal of MOSFET Q3 is connected to a common node between the conducting half-bridge terminal of bidirectional power management chip U1 and the second terminal of inductor L1. The controlled terminal of MOSFET Q3 is connected to the enable / drive terminal of the first right half-bridge of bidirectional power management chip U1. The first conducting terminal of MOSFET Q7 is grounded. The second conducting terminal of MOSFET Q7 is connected to a common node between the conducting half-bridge terminal of bidirectional power management chip U1 and the second terminal of inductor L1. The controlled terminal of MOSFET Q7 is connected to the enable / drive terminal of the second right half-bridge of bidirectional power management chip U1.

[0034] In this embodiment, the charge / discharge management unit comprises a bidirectional power management chip U1, MOSFETs Q2, Q3, Q6, and Q7, and an inductor L1, forming a complete power regulation circuit capable of realizing bidirectional energy flow in both boost and buck modes. The connections between the components are arranged according to the engineering logic of bidirectional energy transfer, enabling the system to automatically switch the current direction and stably regulate the bus voltage under different states such as external device access, system discharge, external input charging, and battery powering the wireless power module. The bidirectional power management chip U1 has two half-bridge conducting terminals that can be used as high-side and low-side switches, respectively. Its first half-bridge conducting terminal is electrically connected to the first terminal of inductor L1, and its second half-bridge conducting terminal is electrically connected to the second terminal of inductor L1. Inductor L1, as the energy storage element in the entire buck-boost topology, is placed between the two half-bridges of the bidirectional power management chip U1 to store and release energy in different switching cycles, thereby completing the energy transfer from external devices to the battery or from the battery to external devices.

[0035] The first conducting terminal of MOSFET Q2 is directly connected to the device connection terminal, and its second conducting terminal is connected to the common node between the first half-bridge conducting terminal of bidirectional power management chip U1 and the first terminal of inductor L1. The controlled terminal of MOSFET Q2 is connected to the first left half-bridge enable driving terminal of bidirectional power management chip U1. Through this connection, MOSFET Q2 is driven to conduct by bidirectional power management chip U1 when the system enters the external device input power supply mode (such as USB-C connected charger), so that the external input current can smoothly enter the left half-bridge region of bidirectional power management chip U1 and participate in the step-down charging process. When the system is in the external discharge mode instead of the input mode, MOSFET Q2 is controlled to turn off to prevent the energy on the battery side from flowing back to the external device.

[0036] The first conducting terminal of MOSFET Q6 is grounded, and the second conducting terminal is also connected to the common node between the first half-bridge conducting terminal of the bidirectional power management chip U1 and the first terminal of inductor L1. Its controlled terminal is connected to the second left half-bridge enable driving terminal of the bidirectional power management chip U1, so that MOSFET Q6 provides a controlled low-side conduction path when the bidirectional power management chip U1 executes buck mode, enabling the first half-bridge to complete the complete PWM switching action. MOSFET Q6 is also used to quickly discharge the common node of the left half-bridge in boost mode, so that the left half-bridge conduction state can achieve a clean falling edge, thereby improving the overall commutation efficiency.

[0037] The first conducting terminal of MOSFET Q3 is directly connected to the battery, and its second conducting terminal is connected to the common node between the second half-bridge conducting terminal of the bidirectional power management chip U1 and the second terminal of inductor L1. The controlled terminal of MOSFET Q3 is connected to the first right half-bridge enable driving terminal of the bidirectional power management chip U1. Through this connection, MOSFET Q3 serves as the main power channel between the battery and the bidirectional power management chip U1. When the system provides energy from the battery to external devices in discharge mode, the current required for charging inductor L1 can be injected into the second half-bridge through MOSFET Q3. In charging mode, MOSFET Q3 is controlled to turn off to prevent external input power from directly returning to the battery through the second half-bridge, thereby ensuring the correct direction of bidirectional energy.

[0038] The first conducting terminal of MOSFET Q7 is grounded, and the second conducting terminal is also connected to the common node between the second half-bridge conducting terminal of bidirectional power management chip U1 and the second terminal of inductor L1. Its controlled terminal is connected to the second right half-bridge enable driving terminal of bidirectional power management chip U1, so that MOSFET Q7 provides the low-side power channel of the second half-bridge, enabling bidirectional power management chip U1 to realize PWM modulation of the second half-bridge during the boost process. MOSFET Q7 is also used to quickly release the node current of the second half-bridge in buck mode, so that inductor L1 can smoothly complete the energy output in the buck cycle, and maintain a stable state of continuous or intermittent conduction in the bidirectional buck-boost process.

[0039] Furthermore, such as Figure 3 As shown, the device connection terminals include terminal USB1 and terminal C2+. The charge / discharge management unit also includes MOSFET Q1 and MOSFET Q8. The first conducting terminal of MOSFET Q1 is connected to terminal USB1, and the first conducting terminal of MOSFET Q8 is connected to terminal C2+. The second conducting terminals of MOSFET Q1 and MOSFET Q8 are merged into the same node to be connected to the first conducting terminal of MOSFET Q2. The controlled terminal of MOSFET Q1 is connected to the first enable signal output terminal of the charge / discharge management unit, and the controlled terminal of MOSFET Q8 is connected to the second enable signal output terminal of the charge / discharge management unit.

[0040] In this embodiment, the device connection terminals consist of terminal USB1 and terminal C2+, and controlled access to the two physical ports is achieved through MOSFETs Q1 and Q8 respectively. Together with MOSFET Q2, they form the external device connection path selection mechanism, enabling the charging and discharging management unit to automatically establish the corresponding power supply or power draw path based on the actual access port. Terminal USB1 is used to connect to a traditional USB-A or USB input module, and its output voltage first reaches the first conducting terminal of MOSFET Q1 when the user inserts the charger or data cable. Similarly, terminal C2+ is used to connect to the USB Type-C interface, and its external input or output voltage signal reaches the first conducting terminal of MOSFET Q8. The second conducting terminals of MOSFETs Q1 and Q8 are merged into the same node, which is directly connected to the first conducting terminal of MOSFET Q2. This allows the input signals of the two ports to converge structurally into the main power path of the charging and discharging management unit, but the actual conducting port is determined by the controlled terminal signal of the corresponding MOSFET.

[0041] The controlled terminal of MOSFET Q1 is connected to the first enable signal output terminal of the charge / discharge management unit, while the controlled terminal of MOSFET Q8 is connected to the second enable signal output terminal of the charge / discharge management unit. The charge / discharge management unit can determine whether to turn on MOSFET Q1 or MOSFET Q8 based on the detected external power supply attributes, Type-C protocol handshake information, or the voltage validity of the USB port. When MOSFET Q1 is turned on, the external power supply or load current at terminal USB1 will enter MOSFET Q2 through a low-loss path, thereby entering the half-bridge input node corresponding to the bidirectional power management chip U1. At this time, MOSFET Q8 remains off because it does not receive an enable signal, ensuring that terminal C2+ is not accidentally powered in reverse or interfered with. When MOSFET Q8 is turned on, the voltage or load current at terminal C2+ enters the node connected to MOSFET Q2 through MOSFET Q8. At this time, MOSFET Q1 remains off because it does not receive the first enable signal, thereby preventing voltage short circuits or reverse current between the two ports.

[0042] MOSFET Q2 is located between the port selection structure and the first half-bridge conduction terminal of the bidirectional power management chip U1. It is the key switching path for all input power from external devices to enter the charge / discharge management unit. When MOSFET Q2 is turned on by the enable drive terminal of the first left half-bridge of the bidirectional power management chip U1, power from terminal USB1 or terminal C2+ can smoothly enter the main buck-boost power circuit formed by the bidirectional power management chip U1 and inductor L1. When MOSFET Q2 is turned off, regardless of whether there is external voltage in terminal USB1 or terminal C2+, power cannot enter the charge / discharge management unit, thus ensuring that the system can maintain a safe power-off state during working mode switching, reverse charging protection, or when no device is connected. As a unified switch after port selection, MOSFET Q2, together with MOSFETs Q1 and Q8, forms a cascade selection link for the external power supply path. This structured arrangement ensures that the system has high robustness and controllability when dealing with different interface specifications, voltage directions, and power supply modes.

[0043] Furthermore, such as Figure 5 As shown, the wireless charging power control module includes a wireless charging transmitter control chip U4, a MOSFET Q5, a capacitor C43, a controllable capacitor bank, and a wireless charging coil LP1. The power input terminal of the wireless charging transmitter control chip U4 is connected to the wireless charging power output terminal of the charging and discharging management unit. The first power output terminal of the wireless charging transmitter control chip U4 is connected to the first terminal of the wireless charging coil LP1. The second power output terminal of the wireless charging transmitter control chip U4 is connected to the first conducting terminal of the MOSFET Q5 and the first terminal of the capacitor C43, respectively. The second conducting terminal of the MOSFET Q5 is connected to the first terminal of the controllable capacitor bank. The second terminal of the controllable capacitor bank and the second terminal of the capacitor C43 are combined into a sampling node, which is connected to the second terminal of the wireless charging coil LP1. The controlled terminal of the MOSFET Q5 is connected to the second power output terminal of the wireless charging transmitter control chip U4.

[0044] In this embodiment, the wireless charging power control module consists of a wireless charging transmitter control chip U4, a MOSFET Q5, a capacitor C43, a controllable capacitor bank, and a wireless charging coil LP1. These components are connected according to the energy flow direction of the wireless power transmission and the parameter adjustment logic of the resonant network, enabling the system to automatically construct corresponding resonant conditions and output stable wireless energy for different external devices. The power input terminal of the wireless charging transmitter control chip U4 is directly connected to the wireless charging power output terminal of the charge / discharge management unit. This connection ensures that U4 receives the bus voltage controlled by the bidirectional power management chip U1 from the charge / discharge management unit during each operation, allowing U4 to establish a stable drive voltage reference according to the device type requirements. The wireless charging transmitter control chip U4 integrates a full-bridge or half-bridge drive structure. Its first power output terminal is connected to the first terminal of the wireless charging coil LP1, enabling U4 to generate a changing magnetic field on the wireless charging coil LP1 using PWM or resonant drive methods for wireless energy transfer to external devices.

[0045] The second power output terminal of the wireless charging transmitter control chip U4 is simultaneously connected to the first conducting terminal of MOSFET Q5 and the first terminal of capacitor C43, forming the main node of the resonant network. This node is responsible for the energy exchange between the drive signal output from U4 and the resonant capacitor branch. The second terminal of capacitor C43 is connected to the second terminal of wireless charging coil LP1 through a sampling node, so that capacitor C43 and wireless charging coil LP1 together form a basic resonant network. When MOSFET Q5 is off, the drive signal output by U4 forms a fixed set of resonant parameters only between capacitor C43 and wireless charging coil LP1. This is suitable for charging scenarios with high output power or wide resonant range requirements, such as wireless charging of smartphones.

[0046] The second conducting terminal of MOSFET Q5 is connected to the first terminal of the controllable capacitor bank. The second terminal of the controllable capacitor bank is then combined with the second terminal of capacitor C43 to form a sampling node. This sampling node is further electrically connected to the second terminal of the wireless charging coil LP1, allowing MOSFET Q5 to connect the controllable capacitor bank in parallel to capacitor C43 when it is controlled to conduct, thus changing the total capacitance of the resonant network. The controlled terminal of MOSFET Q5 is driven by the second power output terminal of the wireless charging transmitter control chip U4, enabling U4 to automatically control MOSFET Q5 to conduct or turn off based on the communication results with external devices, thereby connecting or removing the controllable capacitor bank from the resonant network. The controllable capacitor bank consists of multiple capacitors with different capacitance values, allowing the wireless charging power control module to construct different resonant frequencies with the cooperation of MOSFET Q5 and the upper-level control signal, to adapt to device types such as smartwatches and earphone charging cases that require higher resonant frequencies, lower power, or have special communication methods.

[0047] The two ends of the wireless charging coil LP1 are connected to the first power output terminal of the wireless charging transmitter control chip U4 and the aforementioned sampling node, respectively, making it the transmitting element of the entire resonant network. Under the AC drive signal output by U4, the wireless charging coil LP1 generates an alternating magnetic field, which couples energy with the internal coil of the external receiving device. Its magnetic field strength, coupling efficiency, and power output capability are all affected by the resonant parameters. By using capacitor C43 as a fixed resonant element and a controllable capacitor bank as a dynamically adjustable element, and by controlling the conduction of MOSFET Q5 to form two or more switchable resonant conditions, the wireless charging power control module can construct the corresponding optimal resonant frequency according to different device types (such as mobile phones, headphones, and watches) under different output power, communication frequencies, and charging protocol requirements. This ensures that the wireless charging coil LP1 can achieve high-efficiency, low-loss wireless energy output in various scenarios.

[0048] Furthermore, such as Figure 6 As shown, the wireless charging power control module also includes a resonant capacitor switching drive unit. The resonant capacitor switching drive unit includes a bipolar complementary transistor array Q4. The bipolar complementary transistor array Q4 includes a first switch, a second switch, a first resistor, and a second resistor. The first conducting terminal of the first switch is connected to the second power output terminal of the wireless charging transmitter control chip U4. The second conducting terminal of the first switch and the first terminal of the first resistor are both connected to the controlled terminal of the MOSFET Q5. The second terminal of the first resistor is connected to the first terminal of the second resistor. The second terminal of the second resistor is connected to the first conducting terminal of the second switch. The second conducting terminal of the second switch is grounded. The common node between the second terminal of the first resistor and the first terminal of the second resistor is connected to the controlled terminal of the first switch. The controlled terminal of the second switch is connected to the transmitter start / stop signal output terminal of the main control module.

[0049] In this embodiment, the resonant capacitor switching drive unit is composed of a bipolar complementary transistor array Q4. The bipolar complementary transistor array Q4 includes a first switch, a second switch, a first resistor, and a second resistor. Through its connection with the wireless charging transmitter control chip U4, the MOSFET Q5, and the controllable capacitor bank, it achieves gate signal modulation of the MOSFET Q5, enabling the controllable capacitor bank to stably, quickly, and with anti-interference capabilities connect to or disconnect from the resonant network in different operating modes. The first conducting terminal of the first switch in the bipolar complementary transistor array Q4 is directly connected to the second power output terminal of the wireless charging transmitter control chip U4, allowing the first switch to obtain real-time drive signals from the wireless charging transmitter control chip U4. The second conducting terminal of the first switch and the first terminal of the first resistor are connected together to the controlled terminal of the MOSFET Q5, allowing the control waveform output by the wireless charging transmitter control chip U4 to be applied to the gate node of the MOSFET Q5 through the conducting state of the first switch, thereby determining whether the controllable capacitor bank is incorporated into the resonant capacitor network.

[0050] The second end of the first resistor is connected to the first end of the second resistor. The common node between them serves as the controlled input of the first switch, enabling the first switch to stably turn on or off in switching mode when the potential of this node changes. This ensures that the gate potential of the MOSFET Q5 can be promptly increased or decreased during different operating phases. The second end of the second resistor is electrically connected to the first conducting terminal of the second switch, which is grounded. This allows the second switch to form a low-resistance discharge path to the gate node of the MOSFET Q5 through the second resistor when it is controlled to turn on. This ensures that the gate voltage of the MOSFET Q5 can be quickly reduced when the controllable capacitor bank needs to be turned off, achieving high-speed de-excitation during the resonant capacitor switching process.

[0051] The controlled terminal of the second switch is connected to the transmit / stop signal output terminal of the main control module, enabling the main control module to precisely manage the opening and closing of the second switch through this control path, thereby indirectly controlling the rise and fall of the gate potential of the MOSFET Q5. When the main control module sends a transmit / stop signal, the second switch turns on, which quickly pulls the gate node of the MOSFET Q5 low, causing the controllable capacitor bank to exit the resonant network. When the transmit / stop signal remains off, the second switch no longer turns on, allowing the second power signal output by the wireless charging transmit control chip U4 to be coupled to the MOSFET Q5 through the first switch and the first resistor, thereby allowing the controllable capacitor bank to connect to the resonant network and form a resonant frequency that matches a specific external device.

[0052] Furthermore, such as Figure 5 As shown, the wireless charging power control module also includes a full-bridge high-side input switch Q12, which consists of two MOSFETs connected in series. The first conducting terminal of the full-bridge high-side input switch Q12 is connected to the wireless charging power output terminal of the charging and discharging management unit, and the second conducting terminal of the full-bridge high-side input switch Q12 is connected to the power input terminal of the wireless charging transmitter control chip U4. The controlled terminals of the two MOSFETs in the full-bridge high-side input switch Q12 are connected to the bus voltage start / stop signal output terminal of the bidirectional power management chip U1.

[0053] In this embodiment, the full-bridge high-side input switch Q12 consists of two MOSFETs connected in series. Its first conducting terminal is electrically connected to the wireless charging power output terminal of the charge / discharge management unit, while its second conducting terminal is connected to the power input terminal of the wireless charging transmitter control chip U4, thus forming a controllable power-on switch for the wireless charging transmitter path. The controlled terminals of both MOSFETs in the full-bridge high-side input switch Q12 are connected to the bus voltage start / stop signal output terminal of the bidirectional power management chip U1, enabling the bidirectional power management chip U1 to control the overall conduction or shutdown of Q12 according to the system's operating state. When the wireless charging function needs to be activated, the bidirectional power management chip U1 outputs a valid bus voltage start / stop signal to turn on the full-bridge high-side input switch Q12, thereby allowing the wireless charging transmitter control chip U4 to obtain a stable bus voltage. When the wireless charging function does not need to be activated or the system is in standby mode, this signal turns off Q12, thereby blocking the power supply path to the wireless charging transmitter control chip U4 and avoiding standby losses and unnecessary heat generation at the transmitter. With the Q12's configuration, the wireless charging power control module can obtain clear power-on and power-off logic during different mode switching processes, ensuring the system's safety and energy efficiency when dynamically switching between multiple modes.

[0054] Furthermore, such as Figure 5 As shown, the wireless charging power control module also includes MOSFET Q13, MOSFET Q9, and diode D1. The first conducting terminal of MOSFET Q13 is connected to the battery, the second conducting terminal of MOSFET Q13 is connected to the anode of diode D1, the cathode of diode D1 is connected to the power input terminal of wireless charging transmitter control chip U4, the controlled terminal of MOSFET Q13 is connected to the first conducting terminal of MOSFET Q9, the second conducting terminal of MOSFET Q9 is grounded, and the controlled terminal of MOSFET Q9 is connected to the battery voltage start / stop signal output terminal of bidirectional power management chip U1.

[0055] In this embodiment, to enhance the power supply stability of the wireless charging power control module under specific operating conditions, the system is configured with an auxiliary power input path consisting of MOSFET Q13, MOSFET Q9, and diode D1. The first conducting terminal of MOSFET Q13 is directly connected to the battery, and its second conducting terminal is connected to the anode of diode D1. This allows the battery voltage to provide controlled power to diode D1 through MOSFET Q13 when a specific control signal is valid. The cathode of diode D1 is further connected to the power input terminal of the wireless charging transmitter control chip U4, enabling the battery to provide a backup or compensation power supply path for the wireless charging transmitter control chip U4 when MOSFET Q13 is conducting and diode D1 is forward biased. This ensures that the wireless charging transmitter can still obtain a continuous and stable input voltage even when the main bus voltage experiences a transient drop or the system is in a specific power supply mode.

[0056] The controlled terminal of MOSFET Q13 is connected to the first conducting terminal of MOSFET Q9, while the second conducting terminal of MOSFET Q9 is grounded, making MOSFET Q9 a controlled discharge path for the gate of MOSFET Q13. When MOSFET Q9 is turned on, its second conducting terminal forms a low-resistance pull-down to the gate of MOSFET Q13, causing MOSFET Q13 to turn off quickly. This ensures that the battery voltage is not mistakenly applied to the power input terminal of the wireless charging transmitter control chip U4 when battery power is not required. The controlled terminal of MOSFET Q9 is connected to the battery voltage start / stop signal output terminal of the bidirectional power management chip U1, enabling the bidirectional power management chip U1 to determine whether MOSFET Q13 should be turned on based on the start / stop status of the wireless transmitter function, battery level, or system power scheduling requirements.

[0057] Furthermore, such as Figure 7 As shown, a single-coil wireless charging circuit compatible with multiple devices also includes a protection module. The protection module includes a master control protection chip U2, MOSFET Q10, and MOSFET Q11. MOSFETs Q10 and Q11 are connected in series and form a corresponding power output path with the battery. The controlled terminal of MOSFET Q10 is connected to the first protection output terminal of the master control protection chip U2, and the controlled terminal of MOSFET Q11 is connected to the second protection output terminal of the master control protection chip U2. The first output node of the battery is connected to the first over-discharge detection terminal of the master control protection chip U2, and the second output node of the battery is connected to the second over-discharge detection terminal of the master control protection chip U2.

[0058] In this embodiment, the protection module consists of a main control protection chip U2 and two MOSFETs Q10 and Q11 connected in series, forming a main battery protection link. This link monitors the overall battery status during charging or discharging and executes a rapid current interruption when an abnormality is detected. The battery's first output node is connected to the first over-discharge detection terminal of the main control protection chip U2, and the battery's second output node is connected to the second over-discharge detection terminal of the main control protection chip U2. This allows the main control protection chip U2 to collect the overall terminal voltage of the battery pack and its changing trend in real time, and to determine whether there is over-discharge, overcharge, or abnormal battery output based on the battery's operating stage. MOSFETs Q10 and Q11 are connected in series with their sources facing each other to form a back-to-back switch structure. Together, they form the only controlled conductive link in the battery energy output path. This link simultaneously carries bidirectional current for both battery discharge and external charging. Therefore, the electrical state of its controlled terminal directly determines whether the battery can exchange energy with the rest of the system. The controlled terminal of MOSFET Q10 is connected to the first protection output terminal of the main control protection chip U2, and the controlled terminal of MOSFET Q11 is connected to the second protection output terminal of the main control protection chip U2. This allows the main control protection chip U2 to regulate the gate potential of the two MOSFETs separately, thereby achieving complete shutdown or complete conduction of the entire back-to-back structure by adjusting their conduction states. When the main control protection chip U2 detects over-discharge of the battery, its protection output terminal will quickly pull down the gates of MOSFETs Q10 and Q11, completely shutting down the back-to-back structure, isolating the battery from the system, and preventing further discharge that could damage the battery. When overcharging or abnormally high charging current is detected, the main control protection chip U2 similarly controls MOSFETs Q10 and Q11 to turn off, blocking the external charging path to the battery. Because the back-to-back MOSFET structure avoids the body diode forming a reverse conduction path, reliable current interruption can still be achieved in bidirectional current scenarios, ensuring comprehensive protection for the battery under any abnormal conditions.

[0059] Furthermore, such as Figure 7As shown, the protection module also includes a single-unit protection chip UT1, a single-unit protection chip UT2, a MOSFET QS1, and a MOSFET QS2. The first conducting terminal of MOSFET QS1 is connected to the first output node. The second conducting terminal of MOSFET QS1 is connected to the first conducting terminal of MOSFET QS2. The second conducting terminal of MOSFET QS2 is connected to MOSFET Q11. The common node between the second conducting terminal of MOSFET QS1 and the first conducting terminal of MOSFET QS2 is connected to the second output node and the detection input terminal of single-unit protection chip UT1, respectively. The enable output terminal of single-unit protection chip UT1 is connected to the controlled terminal of MOSFET QS1. The common node between the second conducting terminal of MOSFET QS2 and MOSFET Q11 is connected to the detection input terminal of single-unit protection chip UT2. The enable output terminal of single-unit protection chip UT2 is connected to the controlled terminal of MOSFET QS2.

[0060] In this embodiment, to further enhance the precision of battery protection, in addition to the overall battery protection provided by the master control protection chip U2, the system also includes individual cell protection chips UT1 and UT2. These chips form a cascaded protection structure for the individual cells within the battery via MOSFETs QS1 and QS2. The first conducting terminal of MOSFET QS1 is directly connected to the first output node of the battery, and the second conducting terminal of MOSFET QS1 is connected to the first conducting terminal of MOSFET QS2. This connection point is the intermediate node between the two individual cells and is also connected to the detection input terminal of the individual cell protection chip UT1, enabling UT1 to collect the terminal voltage of the upper half of the individual cells in real time. The second conducting terminal of MOSFET QS2 is ultimately connected to MOSFET Q11, embedding the entire individual cell-level protection link within the overall battery protection path. The common node between MOSFETs QS1 and QS2 is also connected to the second output node of the battery and further connected to the detection input terminal of the individual cell protection chip UT2, enabling UT2 to collect the terminal voltage of the lower half of the individual cells in real time. The enable output of the single-cell protection chip UT1 is connected to the controlled terminal of the MOSFET QS1, so that when the upper half of the single-cell battery cells experience overvoltage or undervoltage, the single-cell protection chip UT1 can quickly control the MOSFET QS1 to turn off, directly cutting off the current path of the corresponding single-cell battery cell. Similarly, the enable output of the single-cell protection chip UT2 is connected to the controlled terminal of the MOSFET QS2, so that it can control the MOSFET QS2 to turn off when the lower half of the single-cell battery cells is abnormal, cutting off the current path of the corresponding battery cell.

[0061] like Figure 8 As shown, a control method for a multi-device compatible single-coil wireless charging circuit is described. The control method includes: S10. Obtain the power supply attributes of the external device and switch to either discharge mode or charging mode based on the power supply attributes. The power supply attributes of the external device refer to the power status information presented to the system by the external terminal through the device connection terminal, including whether the terminal is currently providing power to this circuit as an energy source or being provided with energy by this circuit as a load, as well as the characteristics of the power supply in terms of protocol, voltage level, and directionality. The system will determine whether the external device should be identified as an input power source or an output load based on the power supply attributes, thereby providing a basis for subsequent power scheduling. Discharge mode refers to the working state in which this circuit uses the internal battery as an energy source and delivers energy to the external load through the charge and discharge management unit. Essentially, the system is in an external power supply state. In contrast, charging mode refers to the external power source inputting electrical energy to the battery through the device connection terminal, and the charge and discharge management unit executing step-down control and battery management strategies to keep the battery in the charging stage.

[0062] S20. When in discharge mode and the discharge mode is the wireless charging working mode, configure the corresponding bus voltage output parameters, and power on the external device through the bus voltage generated by the bus voltage output parameters. The wireless charging working mode further defines the energy path provided by this circuit to the external device as a wireless transmission path based on the discharge mode. That is, the wireless charging power control module transmits a magnetic field to the receiving coil of the external device, which is a specific working sub-state of the discharge mode. The bus voltage output parameters are a set of parameters such as the target voltage level, ripple tolerance, and drive strategy set by the main control module according to the wireless transmission requirements. These parameters will adjust the bidirectional power management chip U1 through the charge and discharge management unit so that it outputs a bus voltage that meets the wireless charging transmission conditions after the boost or buck process. The bus voltage is the actual supply voltage generated according to the above bus voltage output parameters. It is the main energy input reference of the wireless charging transmission control chip U4 and is used to drive the resonant network to establish a magnetic field.

[0063] S30. Based on the wireless charging standard protocol, bidirectional communication is established with external devices to identify the device type. The wireless charging standard protocol is the communication specification used between this circuit and external devices. It is used to transmit device identification information, power request information, and energy control information between the transmitter and receiver, enabling the system to establish a unified communication mechanism with devices of different brands and models. The device type is the load category identified by the wireless charging transmitter control chip U4 and the main control module after the initial communication is completed. This includes different wireless charging receivers such as smartphones, smartwatches, and wireless headphones. Each device type has different requirements for operating frequency, resonant parameters, and power level.

[0064] S40. Based on the device type, determine the corresponding wireless charging power parameters. The wireless charging power parameters are the target power settings generated by the main control module after identifying the device type to drive the wireless charging transmission. These parameters include the target operating frequency, duty cycle, equivalent capacitance of the resonant network, power limit value, and feedback dynamic adjustment strategy. They are the key basis for the control of the resonant network and the transmission power.

[0065] S50: Based on the wireless charging power parameters, the system switches to the corresponding resonant capacitor bank, thereby driving a single transmitting coil to output the corresponding wireless power to the external device to achieve wireless charging. The resonant capacitor bank is a controllable combination of capacitors forming the resonant network of the wireless charging transmitter. It consists of fixed capacitors and switchable capacitor branches. By adjusting the number or combination of capacitors participating in the resonance, the equivalent capacitance of the resonant network changes to match the resonant frequency required by different device types. The single transmitting coil is a magnetic field transmitting coil used to transmit wireless power to the external device. It, together with the resonant network, forms a highly efficient energy coupling path. By adjusting the resonant capacitor bank and the bus voltage, the single transmitting coil can output a stable magnetic field strength to meet the corresponding energy requirements under different device types. Wireless power refers to the energy coupled to the receiving coil of the external device in the form of a magnetic field through the single transmitting coil at the resonant frequency. It is the effective wireless charging output ultimately provided by this system to the external device.

[0066] For example, when a user places their smartphone in the wireless charging area, the system first identifies whether the phone is currently providing input power or needs to output power through the device connection terminal, thereby determining the power supply attribute and switching to discharge mode. After the main control module confirms that the discharge mode belongs to the wireless charging working mode, in order to meet the phone's fast wireless charging needs, it configures a higher level of bus voltage output parameters, so that the bidirectional power management chip U1 outputs a bus voltage that meets the resonant drive conditions. The wireless charging transmitter control chip U4 then communicates with the phone based on the wireless charging standard protocol, identifies that the device is a smartphone, and generates wireless charging power parameters according to the power level requested by the phone. This causes the wireless charging power control module to switch to a large capacitor resonant capacitor bank suitable for the phone, so that the single transmitting coil operates at the resonant frequency that matches the smartphone's optimal charging efficiency, ultimately achieving a stable and efficient wireless charging process.

[0067] Specifically, the main control module utilizes the communication modulation and demodulation circuit integrated within the wireless charging transmitter control chip U4 to perform bidirectional communication with external devices via the wireless charging standard protocol to identify device types. When an external device is placed above the wireless charging coil LP1, the wireless charging transmitter control chip U4 first drives the resonant network to output initial card-finding power at a preset frequency and minimum excitation duty cycle according to the protocol requirements. This provides sufficient energy for the external device's receiver rectifier bridge and power management unit to activate its communication modulation unit. After receiving this activation energy, the external device's internal communication load modulation circuit modulates the alternating magnetic field output by the wireless charging transmitter control chip U4 according to the wireless charging standard protocol. By periodically changing the equivalent load impedance at the receiver, it causes slight changes in the DC component and AC envelope characteristics of the transmitter's resonant current. The wireless charging transmitter control chip U4 detects this load disturbance in real time through its built-in communication sampling amplifier and envelope detector, restoring the sampled modulation signal to the protocol-defined ASK or FSK encoded bit stream, and then transmitting the decoded communication frame to the main control module via a serial data interface. The main control module parses the identification fields in the communication frame according to the wireless charging standard protocol. These fields include the device manufacturer's identifier, device category code, effective diameter range of the receiving coil, maximum allowable input power level, communication modulation rate, and whether extended fast charging protocols are supported. These protocol parameters are then matched against a pre-stored device characteristic table to accurately determine whether the external device is a smartphone, smartwatch, wireless headset, or other terminal with wireless charging capabilities. After the device type is determined, the main control module feeds back the parsing results to the wireless charging transmitter control chip U4. Based on the external device's type and power level requirements, it generates a new resonant frequency target, maximum output power limit, and dynamic modulation strategy. This enables the system to construct the optimal wireless charging power output conditions matching the device category, achieving accurate identification and adaptive wireless charging control.

[0068] More specifically, after identifying the device type of the external device, the main control module will construct a corresponding power model based on the device characteristic data reported by the wireless charging standard protocol. By analyzing the device's maximum input power level, equivalent impedance of the receiving coil, optimal operating frequency band, allowable input range of the power management chip, and real-time modulation waveform characteristics fed back by the receiver, the target wireless charging power parameters corresponding to the device are comprehensively determined. The main control module first selects a pre-stored power template based on the device type (such as a smartphone, smartwatch, or wireless earphone). For example, it selects a high-power curve for smartphones, a high-frequency low-power mode for smartwatches, and an ultra-low-power stable mode for wireless earphones. Then, it uses the current, phase difference, and reflection impedance of the transmitting coil LP1 collected by the wireless charging transmitter control chip U4 to calculate the coupling coefficient between the transmitting and receiving sides, thereby evaluating the dynamic matching relationship between the actual output power and the device's allowable absorption power. Subsequently, based on the operating frequency range corresponding to the device type, the main control module selects the appropriate resonant capacitor group participation by solving the LC resonance formula, and calculates the target driving frequency, switching duty cycle reference value, and magnetic field excitation intensity of the wireless charging transmitter control chip U4 to ensure that the resonant network operates near the optimal frequency point of the external device. Meanwhile, based on the maximum input current limit of external devices, the power request value issued by the protocol, and the stability evaluation results of the transmitter bus voltage, the main control module establishes a multi-level power limiting strategy for the power circuit of the wireless charging transmitter control chip U4. This includes setting the maximum output power, maximum current slope, magnetic field excitation rise rate, and temperature feedback adjustment threshold. This generates wireless charging power parameters including the target resonant frequency, equivalent capacitance selection parameters, initial duty cycle value, maximum output limit value, and real-time dynamic adjustment rules. This enables the system to maintain a stable, controllable, and adaptable working state for different devices throughout the entire wireless charging process, and achieves refined power matching for multi-device scenarios.

[0069] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A single-coil wireless charging circuit compatible with multiple devices, characterized in that, The single-coil wireless charging circuit compatible with multiple devices includes a power management module, a main control module, and a wireless charging power control module. The power management module includes a charge / discharge management unit and a device connection terminal. The device connection terminal is used to connect to an external device and is connected to the power connection terminal of the charge / discharge management unit. The charge / discharge management unit identifies the power supply attributes of the external device and switches to the corresponding working direction to output corresponding power when discharging the external device, or to charge the lithium battery when charging. The first control signal output terminal of the main control module is connected to the control signal input terminal of the charge and discharge management unit to configure the bus voltage output parameters of the power connection terminal and the wireless charging power output terminal in the charge and discharge management unit. After the wireless charging power control module receives the bus voltage output according to the bus voltage output parameters, the main control module communicates bidirectionally with the external device through the wireless charging standard protocol to identify the corresponding device type. The power input terminal of the wireless charging power control module is connected to the wireless charging power output terminal of the charging and discharging management unit, and the control signal input terminal of the wireless charging power control module is connected to the second control signal output terminal of the main control module, so as to switch to the corresponding resonant capacitor group according to the device type, and then output wireless charging power parameters adapted to different types of devices.

2. The single-coil wireless charging circuit compatible with multiple devices according to claim 1, characterized in that, The charge / discharge management unit includes a bidirectional power management chip U1, MOSFETs Q2, Q3, Q6, and Q7, and an inductor L1. The first half-bridge conducting terminal of the bidirectional power management chip U1 is connected to the first terminal of the inductor L1, and the second half-bridge conducting terminal of the bidirectional power management chip U1 is connected to the second terminal of the inductor L1. The first conducting terminal of MOSFET Q2 is connected to a device connection terminal, and the second conducting terminal of MOSFET Q2 is connected to a common node between the first half-bridge conducting terminal of the bidirectional power management chip U1 and the first terminal of the inductor L1. The controlled terminal of MOSFET Q2 is connected to the first left half-bridge enable driving terminal of the bidirectional power management chip U1. The first conducting terminal of MOSFET Q6 is grounded, and the second conducting terminal of MOSFET Q6 is connected to the first half-bridge of the bidirectional power management chip U1. At a common node between the bridge conduction terminal and the first terminal of the inductor L1, the controlled terminal of the MOSFET Q6 is connected to the second left half-bridge enable drive terminal of the bidirectional power management chip U1, the first conduction terminal of the MOSFET Q3 is connected to the battery, the second conduction terminal of the MOSFET Q3 is connected to a common node between the second half-bridge conduction terminal of the bidirectional power management chip U1 and the second terminal of the inductor L1, the controlled terminal of the MOSFET Q3 is connected to the first right half-bridge enable drive terminal of the bidirectional power management chip U1, the first conduction terminal of the MOSFET Q7 is grounded, the second conduction terminal of the MOSFET Q7 is connected to a common node between the second half-bridge conduction terminal of the bidirectional power management chip U1 and the second terminal of the inductor L1, and the controlled terminal of the MOSFET Q7 is connected to the second right half-bridge enable drive terminal of the bidirectional power management chip U1.

3. The single-coil wireless charging circuit compatible with multiple devices according to claim 2, characterized in that, The device connection terminals include terminal USB1 and terminal C2+. The charge / discharge management unit also includes MOSFET Q1 and MOSFET Q8. The first conducting terminal of MOSFET Q1 is connected to terminal USB1, and the first conducting terminal of MOSFET Q8 is connected to terminal C2+. The second conducting terminals of MOSFET Q1 and MOSFET Q8 are merged into the same node to be connected to the first conducting terminal of MOSFET Q2. The controlled terminal of MOSFET Q1 is connected to the first enable signal output terminal of the charge / discharge management unit, and the controlled terminal of MOSFET Q8 is connected to the second enable signal output terminal of the charge / discharge management unit.

4. The single-coil wireless charging circuit compatible with multiple devices according to claim 1, characterized in that, The wireless charging power control module includes a wireless charging transmitter control chip U4, a MOSFET Q5, a capacitor C43, a controllable capacitor bank, and a wireless charging coil LP1. The power input terminal of the wireless charging transmitter control chip U4 is connected to the wireless charging power output terminal of the charging and discharging management unit. The first power output terminal of the wireless charging transmitter control chip U4 is connected to the first terminal of the wireless charging coil LP1. The second power output terminal of the wireless charging transmitter control chip U4 is connected to the first conducting terminal of the MOSFET Q5 and the first terminal of the capacitor C43. The second conducting terminal of the MOSFET Q5 is connected to the first terminal of the controllable capacitor bank. The second terminal of the controllable capacitor bank and the second terminal of the capacitor C43 are combined into a sampling node. The sampling node is connected to the second terminal of the wireless charging coil LP1. The controlled terminal of the MOSFET Q5 is connected to the second power output terminal of the wireless charging transmitter control chip U4.

5. A single-coil wireless charging circuit compatible with multiple devices according to claim 4, characterized in that, The wireless charging power control module further includes a resonant capacitor switching drive unit, which includes a bipolar complementary transistor array Q4. The bipolar complementary transistor array Q4 includes a first switch, a second switch, a first resistor, and a second resistor. The first conducting terminal of the first switch and the first terminal of the first resistor are both connected to the second power output terminal of the wireless charging transmitter control chip U4. The second conducting terminal of the first switch and the first terminal of the first resistor are both connected to the controlled terminal of the MOS transistor Q5. The second terminal of the first resistor is connected to the first terminal of the second resistor. The second terminal of the second resistor is connected to the first conducting terminal of the second switch. The second conducting terminal of the second switch is grounded. The common node between the second terminal of the first resistor and the first terminal of the second resistor is connected to the controlled terminal of the first switch. The controlled terminal of the second switch is connected to the transmitter start / stop signal output terminal of the main control module.

6. A single-coil wireless charging circuit compatible with multiple devices according to claim 4, characterized in that, The wireless charging power control module also includes a full-bridge high-side input switch Q12, which consists of two MOSFETs connected in series. The first conducting terminal of the full-bridge high-side input switch Q12 is connected to the wireless charging power output terminal of the charging and discharging management unit, and the second conducting terminal of the full-bridge high-side input switch Q12 is connected to the power input terminal of the wireless charging transmission control chip U4. The controlled terminals of the two MOSFETs in the full-bridge high-side input switch Q12 are connected to the bus voltage start / stop signal output terminal of the bidirectional power management chip U1.

7. A single-coil wireless charging circuit compatible with multiple devices according to claim 4, characterized in that, The wireless charging power control module also includes MOSFET Q13, MOSFET Q9, and diode D1. The first conducting terminal of MOSFET Q13 is connected to the battery, the second conducting terminal of MOSFET Q13 is connected to the anode of diode D1, the cathode of diode D1 is connected to the power input terminal of wireless charging transmitter control chip U4, the controlled terminal of MOSFET Q13 is connected to the first conducting terminal of MOSFET Q9, the second conducting terminal of MOSFET Q9 is grounded, and the controlled terminal of MOSFET Q9 is connected to the battery voltage start / stop signal output terminal of bidirectional power management chip U1.

8. A single-coil wireless charging circuit compatible with multiple devices according to claim 1, characterized in that, The single-coil wireless charging circuit compatible with multiple devices further includes a protection module. The protection module includes a master control protection chip U2, a MOSFET Q10, and a MOSFET Q11. The MOSFETs Q10 and Q11 are connected in series and form a corresponding power output path with the battery. The controlled terminal of the MOSFET Q10 is connected to the first protection output terminal of the master control protection chip U2, and the controlled terminal of the MOSFET Q11 is connected to the second protection output terminal of the master control protection chip U2. The first output node of the battery is connected to the first over-discharge detection terminal of the master control protection chip U2, and the second output node of the battery is connected to the second over-discharge detection terminal of the master control protection chip U2.

9. A single-coil wireless charging circuit compatible with multiple devices according to claim 8, characterized in that, The protection module further includes a single-unit protection chip UT1, a single-unit protection chip UT2, a MOSFET QS1, and a MOSFET QS2. The first conducting terminal of the MOSFET QS1 is connected to the first output node. The second conducting terminal of the MOSFET QS1 is connected to the first conducting terminal of the MOSFET QS2. The second conducting terminal of the MOSFET QS2 is connected to the MOSFET Q11. The common node between the second conducting terminal of the MOSFET QS1 and the first conducting terminal of the MOSFET QS2 is connected to the second output node and the detection input terminal of the single-unit protection chip UT1, respectively. The enable output terminal of the single-unit protection chip UT1 is connected to the controlled terminal of the MOSFET QS1. The common node between the second conducting terminal of the MOSFET QS2 and the MOSFET Q11 is connected to the detection input terminal of the single-unit protection chip UT2. The enable output terminal of the single-unit protection chip UT2 is connected to the controlled terminal of the MOSFET QS2.

10. A control method for a single-coil wireless charging circuit compatible with multiple devices, characterized in that, Using a multi-device compatible single-coil wireless charging circuit as described in any one of claims 1-9, the control method includes: Obtain the power supply attributes of the external device, and switch to either discharge mode or charging mode based on the power supply attributes; When in discharge mode and the discharge mode is wireless charging working mode, configure the corresponding bus voltage output parameters, and power on the external device through the bus voltage generated by the bus voltage output parameters; Based on the wireless charging standard protocol, it communicates bidirectionally with external devices to identify the device type of the external device. Based on the device type, determine the corresponding wireless charging power parameters; The wireless charging power parameters are switched to the corresponding resonant capacitor group, thereby driving a single transmitting coil to output the corresponding wireless power to an external device to achieve wireless charging.

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