Charging circuit and electronic device

Abstract

The utility model belongs to charging technical field, concretely relates to a charging circuit and electronic equipment, aims at solving scheme to rely on hardware stack to increase cost, or the problem that the efficiency is low because of resonance parameter mismatch, always cannot realize balance between " single transmitting end compatible multi -device " and " high -efficient energy transmission ". The charging circuit provided includes: full bridge drive circuit, first drive node and second drive node are included at least in full bridge drive circuit, LC resonance circuit is connected between first drive node and second drive node, and includes multiple parallelly connected transmitting end coil, multiple coil switching switch, at least one coil switching switch is connected with one transmitting end coil in series. Through multiple parallel coils in single LC resonance circuit cooperation switching switch, only needs a set of drive circuit to realize multi -device compatibility, and the circuit structure is greatly simplified, and hardware cost and space occupation are reduced.

Description

Technical Field

[0001] This utility model belongs to the field of charging technology, specifically relating to a charging circuit and electronic device. Background Technology

[0002] In the field of charging, especially wireless charging, achieving efficient compatibility of a single transmitter with multiple different types of devices has always been a technical challenge for the industry. Current technologies typically employ two independent coil and drive circuit schemes when charging devices with different power ratings and resonant parameters, such as mobile phones and smartwatches: for example, using separate wireless charging coils for mobile phones and smartwatches, each matched with its corresponding drive and demodulation circuits. While this approach achieves the functionality, it has significant drawbacks: firstly, the two independent hardware sets result in complex circuit structures and high costs; secondly, the operating frequencies and LC resonant parameters (such as coil turns, inductance, and AC impedance) of different devices vary significantly. Forcing a single traditional coil to be compatible with different devices will lead to low energy transfer efficiency and severe heat generation due to excessive coil impedance at high frequencies, failing to meet the demands of efficient charging across all scenarios. Utility Model Content

[0003] This application provides a charging circuit and electronic device that aims to solve the problem that existing solutions either rely on hardware stacking to increase costs or suffer from low efficiency due to mismatched resonant parameters, and can never achieve a balance between "single transmitter compatibility with multiple devices" and "efficient power transmission".

[0004] In a first aspect, this application provides a charging circuit, comprising: A full-bridge drive circuit, wherein the full-bridge drive circuit includes at least a first drive node and a second drive node; An LC resonant circuit is connected between the first driving node and the second driving node, and the LC resonant circuit includes a plurality of transmitting coils connected in parallel. Multiple coil switching switches, at least one of the coil switching switches being connected in series with one of the transmitting coils.

[0005] In some embodiments, the LC resonant circuit further includes a resonant capacitor connected in series with the parallel connection points corresponding to the plurality of transmitting coils.

[0006] In some embodiments, a plurality of the transmitting coils are connected in parallel to form a first parallel connection point and a second parallel connection point. The first parallel connection point is connected to the first driving node, and the second parallel connection point is connected to the second driving node. The resonant capacitor is connected between the first parallel connection point and the first driving node, or the resonant capacitor is connected between the second parallel connection point and the second driving node.

[0007] In some embodiments, the LC resonant circuit includes a plurality of resonant capacitors connected in parallel and a plurality of resonant switches, wherein the resonant capacitors are connected in series with the resonant switches.

[0008] In some embodiments, the full-bridge drive circuit includes at least a first switch group and a second switch group, wherein the first switch group forms the first drive node and the second switch group forms the second drive node.

[0009] In some embodiments, the first switch group includes at least two switching transistors, and the first drive node is disposed between the two switching transistors.

[0010] In some embodiments, the second switch group includes at least two switching transistors, and the second drive node is disposed between the two switching transistors.

[0011] In some embodiments, the capacitance value of each resonant capacitor is different, and the number of resonant switches is less than or equal to the number of resonant capacitors.

[0012] In some embodiments, the first switch group and the second switch group are respectively connected between a preset power supply and a preset ground terminal. The full-bridge drive circuit includes a first drive mode and a second drive mode. In the first drive mode, the preset power supply is connected to the first drive node and the second drive node is connected to the preset ground terminal. In the second drive mode, the preset power supply is connected to the second drive node and the first drive node is connected to the preset ground terminal.

[0013] In a second aspect, this application provides an electronic device, which includes a charging circuit as provided in any of the first aspects above.

[0014] This application provides a charging circuit that, by creatively introducing an architecture combining "parallel coils and switching switches," fundamentally breaks through the bottlenecks of existing technologies and possesses the following significant advantages: 1. Cost and structural optimization: The design of two independent coils and drive circuits in the traditional solution is abandoned. By using multiple parallel coils in a single LC resonant circuit with a switching switch, only one drive circuit is needed to achieve compatibility with multiple devices, which greatly simplifies the circuit structure and reduces hardware costs and space occupation.

[0015] 2. Highly efficient adaptation to all scenarios: The effective inductance of the transmitting coil is dynamically adjusted by the coil switching switch, and the LC parameters are adjusted synchronously by the resonant capacitor selection switch. This enables the system to adapt to the resonance requirements of different devices in a wide frequency range of 100kHz-2MHz (such as low-frequency high-power scenarios for mobile phones and high-frequency fast / slow charging scenarios for watches). This significantly reduces the AC impedance difference of the coil at different frequencies, improves energy coupling efficiency, and reduces heat generation.

[0016] 3. Enhanced compatibility and flexibility: There is no need to design dedicated transmitters for different devices. By simply switching the coil inductance and resonance parameters, it can match the size differences (such as coil area and number of turns) and LC resonant frequency parameters of receivers such as mobile phones and watches, achieving full-scenario coverage of "one coil, multiple functions" and solving the problem of poor adaptability caused by fixed hardware parameters in traditional solutions.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic block diagram of the charging circuit provided in one embodiment of this application; Figure 2 This is a circuit diagram of the charging circuit provided in one embodiment of this application; Figure 3 This is a schematic block diagram of the structure of an electronic device provided in an embodiment of this application.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] It should be understood that this application can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0023] To fully understand this application, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0024] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other. In the field of wireless charging and power conversion, achieving efficient compatibility of a single transmitter with multiple different types of devices has always been a technical challenge for the industry. Current technologies typically employ two independent coil and drive circuit schemes when charging devices with different power outputs and resonant parameters, such as mobile phones and smartwatches: for example, using separate wireless charging coils for mobile phones and smartwatches, each matched with its corresponding drive and demodulation circuits. While this approach achieves the functionality, it has significant drawbacks: firstly, the two independent hardware sets result in complex circuit structures and high costs; secondly, the operating frequencies and LC resonant parameters (such as coil turns, inductance, and AC impedance) of different devices vary significantly. Forcing a single traditional coil to be compatible with different devices would lead to low energy transfer efficiency and severe heat generation due to excessive coil impedance at high frequencies, failing to meet the demands of efficient charging across all scenarios.

[0025] The core problem with traditional solutions lies in the failure to address how a single coil can adapt to the differences in resonant parameters between different devices. Because mobile phones and watches operate at different frequency ranges (e.g., mobile phone wireless charging typically operates at 100kHz-200kHz, while watch fast charging may involve higher frequencies), and because of inherent differences in coil size and inductance design, a single fixed-parameter LC resonant circuit struggles to achieve efficient coupling across a wide frequency range. While existing technologies have attempted adaptation by adjusting capacitance or frequency, none have addressed the dynamic switching of coil inductance, nor have they proposed a technical approach to flexibly adjust inductance through parallel coils combined with switching devices. Therefore, existing solutions either rely on hardware stacking, increasing costs, or suffer from inefficiency due to mismatched resonant parameters, failing to achieve a balance between "single transmitter compatibility with multiple devices" and "efficient power transmission."

[0026] To resolve the above issues, please refer to [link / reference needed]. Figures 1 to 2This application provides a charging circuit, including a full-bridge drive circuit 11, which includes at least a first drive node and a second drive node; an LC resonant circuit 12 connected between the first drive node and the second drive node, the LC resonant circuit including a plurality of parallel-connected transmitting coils 121; and a plurality of coil switching switches 13, at least one of which is connected in series with a transmitting coil 121.

[0027] Specifically, this utility model provides a tunable wireless charging circuit based on single-coil / multi-coil parallel switching. By dynamically adjusting the LC resonance parameters (inductance L, capacitance C), it achieves efficient wireless charging of a single transmitter compatible with different receiving devices (such as fast / slow charging of mobile phones and watches).

[0028] The full-bridge drive circuit is used to generate a high-frequency drive signal to excite the LC resonant circuit. The LC resonant adjustable unit contains multiple parallel transmitting coils and adjustable capacitors. By switching the combination, the inductance L and capacitance C can be dynamically adjusted. The coil switching switch is used to automatically switch the coil and capacitor combination according to the type of receiving device (such as mobile phone or watch) to match the optimal resonant frequency and impedance.

[0029] The full-bridge drive circuit can be composed of four switching transistors (S1-S4) forming an H-bridge structure. The input is connected to a DC power supply, and the output is the first drive node (SW1) and the second drive node (SW2). By alternately controlling the on / off state of S1 / S4 and S2 / S3 (such as complementary PWM signals), a high-frequency alternating voltage (adjustable from 100kHz to 2MHz) is generated at both ends, driving the LC resonant circuit to generate a high-frequency magnetic field.

[0030] An LC resonant circuit can include transmitting coils (L1-Ln): multiple coils are connected in parallel, and each coil (e.g., L1 corresponds to a mobile phone charging coil, L2 to a watch fast charging coil, and L3 to a watch slow charging coil) has a different number of turns, size, and inductance (L1 > L2 > L3, because the mobile phone receiver is larger and requires a larger inductance; the watch receiver is smaller and has a lower inductance). The coil winding method can be optimized for high-frequency Q value and coupling efficiency through special designs (such as layered winding or multi-strand winding).

[0031] The adjustable resonant capacitors (C1-Cn) are connected in parallel with multiple sets of capacitors. Different capacitor combinations can be selected by switching (S7-Sn) to achieve dynamic adjustment of the capacitance value C (e.g., C1 corresponds to the resonant capacitor of a mobile phone, and C2 corresponds to the fast charging capacitor of a watch).

[0032] The coil switching switches (S5-S6) connect a switch in series with each transmitting coil (e.g., S5 controls the on / off state of L1, S6 controls the on / off state of L2), selecting the coil participating in the resonance by closing / opening the switch. The capacitor switching switches (S7-Sn) control the connection / disconnection of the resonant capacitor, working in conjunction with the coil switching to precisely adjust the LC resonant frequency. ).

[0033] In the corresponding embodiments of this application, the electronic device connected to the receiving end takes mobile phone / watch charging as an example. Device type detection and parameter matching are performed by identifying the device type through handshake signals (such as frequency and power requirements) sent by the transmitting end to the receiving end: Mobile phone charging: requires low frequency band (such as 100-200kHz), high inductance (L1), large coil coupling, and matching the LC resonance parameters of the mobile phone receiver (such as L1+C1 combination). For slow charging of the watch: Requires mid-to-high frequency bands (e.g., 100-500kHz) and medium inductance (L2). Switch to the L2+C2 combination to improve power transfer rate. For fast charging of the watch: Requires high frequency bands (e.g., 1-2MHz) and low inductance (L3). Switch to the L3+C3 combination to reduce heat generation and ensure compatibility with small-sized receivers.

[0034] It should also be noted that the parameters can be adjusted for different mobile phones / watches, and the circuit provided in this application can also charge any type of electronic device. Those skilled in the art can adjust the parameters arbitrarily according to the actual type of device being charged, and the embodiments of this application do not limit this.

[0035] The dynamic switching process includes: Step 1: Full-bridge drive startup: S1-S4 are turned on according to complementary logic, generating high-frequency square waves at both ends to excite the LC resonant circuit. Step 2: Coil and capacitor switching: If a mobile phone receiver is detected, S5 is closed (connected to L1), and S7 is closed (connected to C1), forming an L1+C1 resonant circuit with a resonant frequency f1 matching the mobile phone receiver. If a watch fast charging requirement is detected, S5 is disconnected, S6 is closed (connected to L2), and S8 is closed (connected to C2), forming an L2+C2 circuit with a frequency f2 increased to the frequency band required for fast charging. If the watch is slow charging, S5 and S6 are disconnected, S9 is closed (connected to L3), and S10 is closed (connected to C3), forming an L3+C3 circuit with a further increase in frequency f3 to meet the low inductance requirements of the small coil. Step 3: Energy coupling and transmission: The selected coil generates a high-frequency magnetic field, which is electromagnetically coupled to the receiver, which converts it to DC charging through a demodulation circuit.

[0036] By connecting multiple coils in parallel (not simultaneously), a single circuit can reuse coils with different inductances, avoiding the high cost and complexity of two independent coils in traditional solutions. Coil switching (replaced with L) and capacitor switching (replaced with C) are performed synchronously, ensuring that the resonant frequency f always matches the receiver (e.g., f≈100kHz-500kHz for mobile phones, f≈1-2MHz for fast charging of watches, and f≈100kHz-500kHz for slow charging), reducing AC impedance loss and improving efficiency (traditional solutions suffer from high impedance and low efficiency due to frequency mismatch; this solution improves efficiency through matching). The same transmitter, through switching, is compatible with devices of different sizes, frequencies, and power requirements, covering scenarios such as mobile phones (10W+), fast charging of watches (5W), and slow charging (2W), without requiring additional hardware modules.

[0037] This solution features unique coil winding methods (such as optimization for the number of turns / wire diameter for different devices) and a dynamic LC parameter switching mechanism, which can be extended to: power supply scenarios such as half-bridge drive and AC / DC conversion; scenarios requiring compatibility with different receivers, such as multi-device wireless charging docks and in-vehicle wireless chargers; and any power electronic system that achieves frequency / impedance adaptation by switching coil / inductance values. Through the above design, this utility model breaks through the limitations of traditional wireless charging's "one coil, one device" approach, achieving "one transmitter, multiple scenario compatibility," combining cost advantages with high efficiency.

[0038] In some embodiments, the LC resonant circuit further includes a resonant capacitor connected in series with the parallel connection points corresponding to the plurality of transmitting coils.

[0039] In an LC resonant circuit, the resonant capacitor is connected in series with the parallel connection points of multiple transmitting coils. That is, the resonant capacitor is connected to the "total circuit of the parallel coil group", rather than a single coil branch.

[0040] Multiple transmitting coils (L1-Ln) are first connected in parallel to form a coil group, with their two ends being a common connection point; a resonant capacitor (Cx) is connected in series between this common connection point and the driving node of the full-bridge driving circuit (e.g., a common connection point is first connected to Cx, and then connected to the first driving node).

[0041] When the coil switching switch (such as S5-S6) selects to connect several coils (such as L1+L2 in parallel), the resonant capacitor Cx and the total inductance after parallel connection ( This forms an LC resonant circuit. The LC parameters can be adjusted by switching different coil combinations (changing the total current) or replacing the resonant capacitor (as discussed in subsequent embodiments). By concentrating the resonant capacitors in series in the main circuit, the capacitor switching circuit is simplified, which is suitable for scenarios where the capacitor and coil switching are coordinated (such as when only the coil inductance needs to be adjusted to cover the target frequency).

[0042] In some embodiments, a plurality of the transmitting coils are connected in parallel to form a first parallel connection point and a second parallel connection point. The first parallel connection point is connected to the first driving node, and the second parallel connection point is connected to the second driving node. The resonant capacitor is connected between the first parallel connection point and the first driving node, or the resonant capacitor is connected between the second parallel connection point and the second driving node.

[0043] Multiple transmitting coils are connected in parallel to form a first / second parallel connection point, which is then connected to the first / second driving node of the full-bridge drive, respectively. The resonant capacitor can be connected in series between the driving node and the parallel connection point (two positions: between the first connection point and the first driving node, or between the second connection point and the second driving node).

[0044] The parallel connection structure is connected in parallel with coils, and the two ends are the first parallel connection point and the second parallel connection point. The first parallel connection point is connected to the first drive node (SW1) of the full bridge drive, and the second parallel connection point is connected to the second drive node (SW2).

[0045] Regardless of which side the resonant capacitor is connected to, it forms an LC circuit with the total inductance of the parallel coil. The resonant frequency can be adjusted by switching the coil combination (changing the total inductance) or replacing the capacitor (which requires a switch).

[0046] Application scenarios include: suitable for scenarios that require a fixed capacitor position and rely mainly on coil switching (such as using a large coil + fixed capacitor for mobile phone charging, and a small coil + the same capacitor for watch charging, with frequency matching achieved solely through changes in coil inductance).

[0047] In some embodiments, the LC resonant circuit includes a plurality of resonant capacitors connected in parallel and a plurality of resonant switches, wherein the resonant capacitors are connected in series with the resonant switches.

[0048] An LC resonant circuit contains multiple resonant capacitors connected in parallel. Each capacitor is connected in series with an independent resonant switch. The combination of capacitors connected is selected by switching the switch on and off, thereby achieving dynamic adjustment of the capacitance value.

[0049] The capacitor array design uses a group of resonant capacitors (C1-Cn) connected in parallel, with each capacitor Ck connected in series with a resonant switch Sk (k=1 to n), and the two ends of the total capacitor are connected to the common connection point of the parallel coils.

[0050] The switching logic works by disconnecting a large-capacity capacitor (e.g., C1=100nF) and closing a small-capacity capacitor (e.g., C2=47nF) when high-frequency resonance is needed (e.g., fast charging of a watch), thus reducing the total capacitance and increasing the frequency (f∝1 / √C). It also supports the connection of capacitor combinations (e.g., C2+C3 in parallel, with the capacitance values ​​superimposed) to achieve more precise capacitance adjustment (e.g., adjustable in increments from 47nF to 100nF).

[0051] Coordination with coil switching includes: for example, when charging a mobile phone, connecting a large coil (L1=5μH-9uH) + a large capacitor (C1+C3=103nF-506.8nF), f≈100kHz-165kHz; when slow charging a watch, switching to a small coil (L1=2μH-5uH) + a minimum capacitor (C1=3nF-6.8nF), f≈1.3MHz-1.36MHz. The capacitor values ​​can be flexibly combined, forming a two-dimensional parameter adjustment (both L and C are variable) with the coil inductance switching, covering a wider frequency range (100kHz-2MHz).

[0052] In some embodiments, the full-bridge drive circuit includes at least a first switch group and a second switch group, wherein the first switch group forms the first drive node and the second switch group forms the second drive node.

[0053] The full-bridge drive circuit is divided into a first switch group and a second switch group, which form the first drive node (SW1) and the second drive node (SW2) respectively, and are used to output high-frequency alternating voltage to drive the LC resonant circuit.

[0054] The full-bridge structure is broken down as follows: First switch group: upper bridge arm switch S1 (such as MOSFET) is connected to the power supply PVIN, lower bridge arm switch S2 is connected to the ground terminal GND, and the first drive node is located between S1 and S2; Second switch group: upper bridge arm switch S3 is connected to PVIN, lower bridge arm switch S4 is connected to GND, and the SW2 node is located between S3 and S4.

[0055] The driving signals include: complementary conduction of the first and second switch groups: when S1 and S4 are on, the voltage of the first driving node is PVIN, the voltage of the second driving node is GND, and the LC circuit voltage is PVIN; when S2 and S3 are on, the voltage of the first driving node is GND, the voltage of the second driving node is PVIN, and the LC circuit voltage is -PVIN, forming alternating drive. Through the alternating conduction of the two sets of switches, a high-frequency square wave (frequency controlled by PWM) is generated at the first and second driving nodes, which excites the LC resonant circuit to generate a high-frequency magnetic field.

[0056] In some embodiments, the first switch group includes at least two switching transistors, and the first drive node is disposed between the two switching transistors.

[0057] The first switch group contains at least two switching transistors (one for the upper bridge arm and one for the lower bridge arm), and the first drive node (SW1) is located between the two switching transistors, that is, at the midpoint between the upper and lower bridge arms.

[0058] Switch group structure: The first switch group consists of upper bridge arm switch S1 (N type or P type) and lower bridge arm switch S2. The drain of S1 is connected to the power supply PVIN, the source is connected to the drain of S2, and the source of S2 is connected to GND. The first driving node is the midpoint of the connection between S1 and S2.

[0059] The operating modes include: when S1 is on and S2 is off, the voltage of the first drive node is approximately equal to PVIN; when S1 is off and S2 is on, the voltage of the first drive node is approximately equal to GND; the effective value of the output voltage of the first drive node is adjusted by controlling the duty cycle of S1 / S2 through PWM (for power regulation).

[0060] The second switch group has the same structure as the full bridge, and the second drive node is located between S3 and S4. The two switch groups complement each other to achieve full bridge drive of the H bridge.

[0061] In some embodiments, the second switch group includes at least two switching transistors, and the second drive node is disposed between the two switching transistors.

[0062] The second switch group is symmetrical to the first switch group and contains at least two switching transistors. The second drive node (SW2) is located between the two switching transistors and together with the first drive node (SW1) forms the output terminal of the full-bridge drive.

[0063] The symmetrical design utilizes a second switch group consisting of an upper bridge arm S3 and a lower bridge arm S4, with the connection method mirroring the first switch group: the drain of S3 is connected to PVIN, the source of S3 is connected to the drain of S4, and the source of S4 is connected to GND. The second drive node is the midpoint of the connection. Complementary drive logic: When the first switch group S1 is on and S2 is off, the second switch group S4 is on and S3 is off, forming a loop where the voltage of the first drive node = PVIN → the voltage of the second drive node = GND; when the first switch group S2 is on and S1 is off, the second switch group S3 is on and S4 is off, forming a loop where the voltage of the second drive node = PVIN → the voltage of the first drive node = GND, thus achieving voltage direction reversal. This symmetrical structure ensures the stability of the drive signal, avoids bridge arm shoot-through (requiring a dead time), and improves circuit reliability.

[0064] In some embodiments, the capacitance value of each of the resonant capacitors is different, and the number of the resonant switches is less than or equal to the number of the resonant capacitors.

[0065] By using the different capacitance values ​​of each capacitor in the resonant capacitor bank and ensuring that the number of resonant switches is less than or equal to the number of capacitors, it is possible to select one or more capacitors to be connected in parallel through switch combinations, thereby achieving flexible adjustment of capacitance values.

[0066] Capacitor configuration strategies include: designing capacitor values ​​according to binary or arithmetic sequences, and achieving multi-level capacitance values ​​through switch combinations (e.g., n capacitors can achieve 2...). n-1 tolerance value).

[0067] The number of switches is optimized so that if the number of capacitors is 3 (C1-C3), the number of switches is 3 (each capacitor is connected in series with a switch), which supports individual or combined access without the need for an additional master switch (because parallel circuits can be controlled independently).

[0068] Coordination with coil switching: For example, for slow charging of watches (high frequency), a small coil (L2=6uH-8μH) + small capacitor combination (C1+C2=50nF-200nF) is selected, with f≈125kHz-290kHz; for fast charging of watches (higher frequency), the minimum coil (L1=2μH-5uH) + minimum capacitor (C1=3nF-6.8nF) is switched, with f≈1.3MHz-1.36MHz. This capacitance combination expands the adjustment accuracy, reduces the number of capacitors (number of switches ≤ number of capacitors), and lowers hardware costs.

[0069] In some embodiments, the first switch group and the second switch group are respectively connected between a preset power supply and a preset ground terminal. The full-bridge drive circuit includes a first drive mode and a second drive mode. In the first drive mode, the preset power supply is connected to the first drive node and the second drive node is connected to the preset ground terminal. In the second drive mode, the preset power supply is connected to the second drive node and the first drive node is connected to the preset ground terminal.

[0070] The full-bridge drive circuit supports two drive modes. By switching the conduction direction of the switch group, an alternating voltage is generated across the LC resonant circuit to achieve high-frequency energy excitation.

[0071] The first driving mode (forward conduction) includes: the upper bridge arm S1 of the first switch group is turned on and the lower bridge arm S2 is turned off, and the voltage of the first driving node is PVIN; the lower bridge arm S4 of the second switch group is turned on and the upper bridge arm S3 is turned off, and the voltage of the second driving node is GND; the current path is: PVIN→S1→first driving node→LC resonant circuit→second driving node→S4→GND, and the voltage across the LC is +PVIN.

[0072] The second driving mode (reverse conduction) includes: the lower bridge arm S2 of the first switch group is turned on and the upper bridge arm S1 is turned off, and the voltage of the first driving node is GND; the upper bridge arm S3 of the second switch group is turned on and the lower bridge arm S4 is turned off, and the voltage of the second driving node is PVIN; the current path is: PVIN→S3→SW2→LC resonant circuit→SW1→S2→GND, and the voltage across the LC is -PVIN.

[0073] The two modes alternate at high frequencies (e.g., 100kHz-2MHz), forming a sinusoidal resonance in the LC circuit (actually a square wave drive, which is close to a sine wave after LC filtering), generating a high-frequency alternating magnetic field. The bidirectional voltage output of the full-bridge drive maximizes the energy excitation efficiency of the LC resonant circuit, improving the power output capability compared to the half-bridge drive (voltage swing is 2PVIN vs. half-bridge PVIN).

[0074] This application provides a charging circuit that, by creatively introducing an architecture combining parallel coils and switching switches, fundamentally breaks through the bottlenecks of existing technologies and possesses the following significant advantages: 1. Cost and structural optimization: The design of two independent coils and drive circuits in the traditional solution is abandoned. By using multiple parallel coils in a single LC resonant circuit with a switching switch, only one drive circuit is needed to achieve compatibility with multiple devices, which greatly simplifies the circuit structure and reduces hardware costs and space occupation.

[0075] 2. High-efficiency adaptation for all scenarios: The effective inductance of the transmitting coil is dynamically adjusted by the coil switching switch, and the LC parameters are adjusted synchronously by the resonant capacitor selection switch. This enables the system to adapt to the resonance requirements of different devices in a wide frequency range of 100kHz-2MHz (such as low-frequency high-power scenarios for mobile phones and high-frequency fast / slow charging scenarios for watches). This significantly reduces the AC impedance difference of the coil at different frequencies, improves energy coupling efficiency, and reduces heat generation.

[0076] 3. Enhanced compatibility and flexibility: There is no need to design dedicated transmitters for different devices. By simply switching the coil inductance and resonance parameters, it can match the size differences (such as coil area and number of turns) and LC resonant frequency parameters of receivers such as mobile phones and watches, achieving full-scenario coverage of "one coil, multiple functions" and solving the problem of poor adaptability caused by fixed hardware parameters in traditional solutions.

[0077] Please refer to the foregoing embodiments. Figure 3 , Figure 3 This is a schematic block diagram illustrating the structure of an electronic device 100 provided in some embodiments of this application. The electronic device 100 includes a charging circuit 10 provided in any embodiment of this application.

[0078] In some embodiments, the provided charging circuit 10 includes a full-bridge drive circuit 11, which includes at least a first drive node and a second drive node; an LC resonant circuit 12 connected between the first drive node and the second drive node, which includes a plurality of parallel-connected transmitter coils 121; and a plurality of coil switching switches 13, at least one of which is connected in series with a transmitter coil 121.

[0079] The specific principles and implementation methods of the electronic devices provided in this application are similar to the charging circuits in the aforementioned embodiments, and will not be repeated here.

[0080] It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. It should be understood that when an element or layer is referred to as “on,” “adjacent to,” “connected to,” or “coupled to” other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as “directly on,” “directly adjacent to,” “directly connected to,” or “directly coupled to” other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion.

[0081] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0082] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0083] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0084] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A charging circuit, characterized in that, include: A full-bridge drive circuit, wherein the full-bridge drive circuit includes at least a first drive node and a second drive node; An LC resonant circuit is connected between the first driving node and the second driving node, and the LC resonant circuit includes a plurality of transmitting coils connected in parallel. Multiple coil switching switches, at least one of the coil switching switches being connected in series with one of the transmitting coils.

2. The charging circuit according to claim 1, characterized in that, The LC resonant circuit also includes a resonant capacitor, which is connected in series with the parallel connection points corresponding to the multiple transmitting coils.

3. The charging circuit according to claim 2, characterized in that, Multiple transmitting coils are connected in parallel to form a first parallel connection point and a second parallel connection point. The first parallel connection point is connected to the first driving node, and the second parallel connection point is connected to the second driving node. The resonant capacitor is connected between the first parallel connection point and the first driving node, or the resonant capacitor is connected between the second parallel connection point and the second driving node.

4. The charging circuit according to claim 2, characterized in that, The LC resonant circuit includes multiple resonant capacitors connected in parallel and multiple resonant switches, with the resonant capacitors connected in series with the resonant switches.

5. The charging circuit according to claim 1, characterized in that, The full-bridge drive circuit includes at least a first switch group and a second switch group, wherein the first switch group forms the first drive node and the second switch group forms the second drive node.

6. The charging circuit according to claim 5, characterized in that, The first switch group includes at least two switching transistors, and the first drive node is disposed between the two switching transistors.

7. The charging circuit according to claim 5, characterized in that, The second switch group includes at least two switching transistors, and the second drive node is disposed between the two switching transistors.

8. The charging circuit according to claim 4, characterized in that, Each of the resonant capacitors has a different capacitance value, and the number of the resonant switches is less than or equal to the number of the resonant capacitors.

9. The charging circuit according to claim 5, characterized in that, The first switch group and the second switch group are respectively connected between a preset power supply and a preset ground terminal. The full-bridge drive circuit includes a first drive mode and a second drive mode. In the first drive mode, the preset power supply is connected to the first drive node and the second drive node is connected to the preset ground terminal. In the second drive mode, the preset power supply is connected to the second drive node and the first drive node is connected to the preset ground terminal.

10. An electronic device, characterized in that, The electronic device includes the charging circuit according to any one of claims 1-9.

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