Modulation method and apparatus for wireless charging system, and wireless charging system

Abstract

The present disclosure relates to the technical field of wireless charging, and provides a modulation method and apparatus for a wireless charging system, and a wireless charging system. The method comprises: in response to the startup of a wireless charging system, controlling the operation of a rectifying circuit on the basis of a pre-configured rectification logic, so as to rectify the energy obtained by coil coupling at a receiving end; monitoring an operating state of a lower MOS transistor during the operation of the rectifying circuit; and if it is monitored that the operating state of the lower MOS transistor switches from an on state to an off state, controlling the lower MOS transistor to turn off with a delay on the basis of a pre-configured turn-off delay parameter. The modulation method and apparatus for a wireless charging system, and the wireless charging system provided by the present disclosure allow the lower MOS transistor to turn off with a delay on the basis of the pre-configured turn-off delay parameter, so as to achieve communication modulation at the receiving end; and in addition, the entire modulation process does not require additional material costs, and the flexibility of modulation depth adjustment is improved, thereby meeting diverse application requirements.

Description

Modulation method, device and wireless charging system for wireless charging system

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 2024119216162, filed on December 25, 2024, entitled "Modulation Method, Apparatus and Wireless Charging System for Wireless Charging System", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the technical field of wireless charging, and in particular to a modulation method, apparatus and wireless charging system for a wireless charging system. Background Technology

[0004] In the field of wireless charging, to ensure the safety and stability of power transmission, a communication mechanism is typically required between the transmitter (Tx) and receiver (Rx) of the wireless charging system. To this end, related technologies employ signal modulation at the receiver (Rx). Specifically, a capacitor and a corresponding control switch are connected to the resonant circuit at the receiver. During wireless charging, the capacitor is connected or removed via the control switch, thereby altering the resonant parameters in the resonant circuit and achieving load modulation at the receiver.

[0005] However, this design not only increases material costs, but also limits the ability to continuously adjust the modulation depth because the modulation depth is limited by the actual modulation capacitor value, making it difficult to meet the needs of different application scenarios.

[0006] Application content

[0007] In view of this, the purpose of this disclosure is to provide a modulation method, apparatus and wireless charging system for a wireless charging system, which can achieve load modulation effect at the receiving end of the wireless charging system without increasing material costs.

[0008] This disclosure provides a modulation method for a wireless charging system, applied to a wireless charging system including a transmitter and a receiver. The receiver includes a receiver coil and a rectifier circuit connected to the receiver coil, the rectifier circuit being a circuit based on a MOSFET. The method includes: responding to the start of the wireless charging system, controlling the operation of the rectifier circuit according to a pre-configured rectification logic to rectify the energy coupled from the receiver coil; monitoring the operating state of the lower MOSFET during the operation of the rectifier circuit; wherein the lower MOSFET is the MOSFET in the rectifier circuit closest to the ground terminal; if the operating state of the lower MOSFET is detected to switch from an on state to an off state, controlling the lower MOSFET to turn off with a delay according to a pre-configured delay turn-off parameter.

[0009] This disclosure provides a possible implementation of a modulation method for a wireless charging system, wherein the aforementioned delay shutdown parameter is used to characterize the delay duration of the lower MOSFET's delayed shutdown; the step of controlling the lower MOSFET's delayed shutdown according to the pre-configured delay shutdown parameter includes: in response to the lower MOSFET's operating state switching from an on state to an off state, controlling the lower MOSFET to maintain the on state; recording the duration of the on state, and if the duration of the on state reaches the delay duration corresponding to the delay shutdown parameter, then controlling the lower MOSFET to turn off.

[0010] This disclosure provides another possible implementation of the modulation method for a wireless charging system, wherein the method further includes: monitoring the current parameters corresponding to the lower MOSFET during the delayed turn-off phase; generating a modulation signal based on the current parameters; and sending the modulation signal to the transmitter.

[0011] This disclosure provides another possible implementation of the modulation method for a wireless charging system, wherein the rectifier circuit includes a first upper MOSFET, a second upper MOSFET, a first lower MOSFET, and a second lower MOSFET; wherein a first terminal of the first upper MOSFET is connected to a power supply pin, a second terminal of the first upper MOSFET is connected to a first terminal of the first lower MOSFET, and a second terminal of the first lower MOSFET is grounded; a first terminal of the second upper MOSFET is connected to a power supply pin, a second terminal of the second upper MOSFET is connected to a first terminal of the second lower MOSFET, and a second terminal of the second lower MOSFET is grounded; one end of the receiving coil is connected to the connection path of the first upper MOSFET and the first lower MOSFET, and the other end of the receiving coil is connected to the connection path of the second upper MOSFET and the second lower MOSFET; the step of controlling the operation of the rectifier circuit according to a pre-configured rectifier logic to rectify the energy coupled by the receiving coil includes: controlling the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET to be alternately turned on according to the pre-configured rectifier logic to rectify the energy coupled by the receiving coil.

[0012] This disclosure provides another possible implementation of the modulation method for a wireless charging system, wherein the step of monitoring the operating state of the lower MOSFET during the operation of the rectifier circuit includes: monitoring the operating states of the first lower MOSFET and the second lower MOSFET during the operation of the rectifier circuit.

[0013] This disclosure provides another possible implementation of the modulation method for a wireless charging system, wherein the step of controlling the lower MOSFET to remain in the on state in response to the switching of the operating state of the lower MOSFET from the on state to the off state includes: controlling the first lower MOSFET to remain in the on state in response to the switching of the operating state of the first lower MOSFET from the on state to the off state, and controlling the first upper MOSFET to remain in the off state; and controlling the second upper MOSFET to turn off and controlling the second lower MOSFET to turn on; or, controlling the second lower MOSFET to remain in the on state in response to the switching of the operating state of the second lower MOSFET from the on state to the off state, and controlling the second upper MOSFET to remain in the off state; and controlling the first upper MOSFET to turn off and controlling the first lower MOSFET to turn on.

[0014] This disclosure provides another possible implementation of the modulation method for a wireless charging system, wherein the receiving end is further configured with a rectifier driving circuit, the rectifier driving circuit having a control interface corresponding to each MOSFET; the control interface is connected to the control terminal of the corresponding MOSFET; the step of controlling the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET to conduct alternately according to a pre-configured rectification logic includes: controlling the rectifier driving circuit to generate control signals for the first upper MOSFET, the second lower MOSFET, the second upper MOSFET, and the first lower MOSFET according to the rectification logic; and outputting the control signals through the control interface to control the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET to conduct alternately.

[0015] This disclosure also provides a modulation device for a wireless charging system, applied to a wireless charging system including a transmitter and a receiver. The receiver includes a receiver coil and a rectifier circuit connected to the receiver coil, the rectifier circuit being a circuit based on a MOSFET. The device includes: a rectifier module configured to respond to the start of the wireless charging system and control the operation of the rectifier circuit according to a pre-configured rectifier logic to rectify the energy coupled from the receiver coil; a monitoring module configured to monitor the operating state of the lower MOSFET during the operation of the rectifier circuit; wherein the lower MOSFET is the MOSFET in the rectifier circuit closest to the ground terminal; and a modulation module configured to control the lower MOSFET to delay turn off according to a pre-configured delay turn-off parameter if the operating state of the lower MOSFET is detected to switch from an on state to an off state.

[0016] This disclosure also provides a wireless charging system, which includes a transmitter and a receiver. The controller of the receiver is configured with the modulation device of the wireless charging system described above. The receiver also includes a receiver coil and a rectifier circuit connected to the receiver coil. The rectifier circuit is a circuit based on a MOSFET. The rectifier circuit is connected to the controller.

[0017] This disclosure provides a possible implementation of a wireless charging system, wherein the rectifier circuit includes a first upper MOSFET, a second upper MOSFET, a first lower MOSFET, and a second lower MOSFET; wherein a first terminal of the first upper MOSFET is connected to a power supply pin, a second terminal of the first upper MOSFET is connected to a first terminal of the first lower MOSFET, and a second terminal of the first lower MOSFET is grounded; a first terminal of the second upper MOSFET is connected to a power supply pin, a second terminal of the second upper MOSFET is connected to a first terminal of the second lower MOSFET, and a second terminal of the second lower MOSFET is grounded; one end of the receiving coil is connected to the connection path of the first upper MOSFET and the first lower MOSFET, and the other end of the receiving coil is connected to the connection path of the second upper MOSFET and the second lower MOSFET; the receiving end is further configured with a rectifier drive circuit, the rectifier drive circuit being provided with a control interface corresponding to each MOSFET; the control interface is connected to the control terminal of the corresponding MOSFET.

[0018] The embodiments disclosed herein bring the following beneficial effects:

[0019] The modulation method, apparatus, and wireless charging system provided in this disclosure can respond to the start of the wireless charging system by controlling the operation of the rectifier circuit according to the pre-configured rectifier logic to rectify the energy coupled from the coil at the receiving end. It also monitors the operating state of the lower MOSFET during the operation of the rectifier circuit. If the operating state of the lower MOSFET is detected to switch from the on state to the off state, the lower MOSFET is controlled to be turned off in a delayed manner according to the pre-configured delayed turn-off parameters. This delayed turn-off of the lower MOSFET can generate a significant modulation current in the resonant cavity at the receiving end. These modulation currents cause a significant phase change in the resonant cavity current, thereby achieving communication modulation at the receiving end. Simultaneously, at the transmitting end, demodulation can be achieved by detecting the phase change of the coil current signal, thus realizing the communication mechanism between the transmitting and receiving ends. Furthermore, the entire modulation process does not require additional material costs and improves the flexibility of modulation depth adjustment to adapt to diverse application needs.

[0020] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objects and other advantages of this disclosure are realized and obtained through the structures particularly pointed out in the description, claims and drawings.

[0021] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 is a schematic diagram of load modulation;

[0024] Figure 2 is a schematic diagram of a wireless charging system provided in an embodiment of this disclosure;

[0025] Figure 3 is a flowchart of a modulation method for a wireless charging system provided in an embodiment of this disclosure;

[0026] Figure 4 is a schematic diagram of a signal flow provided in an embodiment of this disclosure;

[0027] Figure 5 is a schematic diagram of a modulation signal provided in an embodiment of this disclosure;

[0028] Figure 6 is a structural block diagram of a modulation device for a wireless charging system provided in an embodiment of this disclosure. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0030] Currently, in the field of wireless charging, the communication mechanism between the transmitter and receiver of a wireless charging system must meet the in-band communication protocol based on capacitor modulation established by the Wireless Power Consortium (WPC). Figure 1 shows a load modulation schematic diagram, including schematic diagrams of the transmitter and receiver of the wireless charging system. Optionally, Figure 1 shows coil L2 of the transmitter and coil L1 of the receiver. Energy transfer between the transmitter and receiver of the wireless charging system is achieved through coil coupling. Furthermore, the receiver also includes a rectifier circuit, namely the rectifier circuit composed of diodes D1, D2, D3, and D4 in Figure 1.

[0031] Based on the circuit diagram shown in Figure 1, the two signals LM1 and LM2 are responsible for controlling the two switching transistors Q1 and Q2, respectively, to connect or remove capacitors C6 and C7 from the resonant circuit, thereby changing the LC resonant parameters in the receiver and realizing load modulation. In addition, Figure 1 also shows other components, such as the load Rload, the load capacitor C2, and the resonant capacitors C1 and C4, etc.

[0032] However, the design described in Figure 1 not only increases material costs (e.g., capacitors C6 and C7, switching transistors Q1 and Q2, and the load control circuit), but also limits the continuous adjustment capability of the modulation depth because it is constrained by the actual modulation capacitor value, making it difficult to meet the needs of different application scenarios. Therefore, in IC design, two pairs of LM control pins are typically reserved, and each LM pair is configured with a modulation capacitor of a different value. The specific LM capacitor pair is selected via firmware to adjust the modulation depth. While this method is feasible, it consumes more IC pin resources and also increases material costs.

[0033] Based on this, the modulation method, apparatus and wireless charging system of the wireless charging system provided in this disclosure can achieve the load modulation effect at the receiving end while also saving material costs.

[0034] To facilitate understanding of this embodiment, a modulation method for a wireless charging system disclosed in this disclosure will first be described in detail.

[0035] The modulation method of the wireless charging system in this embodiment is applied to a wireless charging system, which includes a transmitter and a receiver. The receiver includes a receiver coil and a rectifier circuit connected to the receiver coil. The rectifier circuit is a circuit based on a MOS transistor.

[0036] For ease of understanding, Figure 2 shows a schematic diagram of a wireless charging system, including a transmitter and a receiver. The transmitter only shows the transmitter coil L2 and the capacitor C for illustrative purposes. The receiver further shows the receiver coil L1, resonant capacitors C1 and C2, as well as a rectifier circuit, a capacitor C3 at the load output terminal, and a load Rload. The rectifier circuit includes a first upper MOSFET M1, a second upper MOSFET M2, a first lower MOSFET M3, and a second lower MOSFET M4.

[0037] The first terminal of the first upper MOSFET M1 is connected to the power supply pin VCC, which is configured to supply power to the MOSFETs in the rectifier circuit. The second terminal of the first upper MOSFET is connected to the first terminal of the first lower MOSFET M3, and the second terminal of the first lower MOSFET M3 is grounded. The first terminal of the second upper MOSFET M2 is connected to the power supply pin VCC, and the second terminal of the second upper MOSFET M2 is connected to the first terminal of the second lower MOSFET M4, and the second terminal of the second lower MOSFET M4 is grounded.

[0038] Furthermore, as shown in Figure 2, one end of the receiving coil L1 is connected to the connection path of the first upper MOSFET M1 and the first lower MOSFET M3, and the other end of the receiving coil L2 is connected to the connection path of the second upper MOSFET M2 and the second lower MOSFET M4.

[0039] In practical use, based on the wireless charging system shown in Figure 2, the rectifier circuit composed of four MOSFETs is a rectifier bridge circuit, which can rectify the output of the LC resonant network at the receiver end of the wireless charging system. Typically, a corresponding control circuit can be configured at the receiver end to control the MOSFETs. The control circuit usually includes logic controllers, comparators, and other logic circuits to control the conduction and cutoff of the four MOSFETs.

[0040] Based on the wireless charging system shown in Figure 2, Figure 3 also shows a flowchart of a modulation method for the wireless charging system, as shown in Figure 3, including the following steps:

[0041] Step S302: In response to the start of the wireless charging system, the rectifier circuit is controlled to operate according to the pre-configured rectifier logic to rectify the energy coupled from the receiving coil.

[0042] Step S304: Monitor the operating status of the lower MOSFET during the operation of the rectifier circuit;

[0043] In this embodiment of the present disclosure, the lower MOS transistor is the MOS transistor closest to the ground terminal in the rectifier circuit, such as the first lower MOS transistor M3 and the second lower MOS transistor M4 in Figure 2.

[0044] Step S306: If the operating state of the lower MOSFET is detected to switch from the on state to the off state, the lower MOSFET is controlled to be turned off with a delay according to the pre-configured delay turn-off parameters.

[0045] The aforementioned off state is also called the cut-off state. In actual use, to implement the rectification logic of the rectifier circuit, the first upper MOSFET M1, the second upper MOSFET M2, the first lower MOSFET M3, and the second lower MOSFET M4 in Figure 2 are alternately turned on. That is, the first upper MOSFET and the second lower MOSFET are turned on simultaneously, and while the first upper MOSFET and the second lower MOSFET are turned on, the second upper MOSFET and the first lower MOSFET are turned off. Similarly, while the first upper MOSFET and the second lower MOSFET are turned off, the second upper MOSFET and the first lower MOSFET are turned on, thus achieving the rectification purpose.

[0046] Therefore, in step S302 above, when the rectifier circuit is controlled to run according to the pre-configured rectifier logic, the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET need to be alternately turned on according to the pre-configured rectifier logic to rectify the energy coupled by the receiving coil. The specific rectifier control logic depends on the actual use case, and this embodiment does not limit it.

[0047] Under normal rectification conditions, if the receiver is not modulated, when the wireless charging system is started and the load is being charged, the receiver can rectify the energy coupled by the receiver coil according to the above step S302, and then charge the load.

[0048] To ensure the safety and stability of power transmission, a communication mechanism needs to be established between the transmitter and receiver of the wireless charging system. Therefore, load modulation needs to be performed at the receiver, that is, during the load charging process at the receiver, the transmitter and receiver communicate with each other.

[0049] In this embodiment of the present disclosure, the operating state of the lower MOSFET of the rectifier circuit is monitored, and when the operating state of the lower MOSFET is detected to switch from the on state to the off state, the lower MOSFET is controlled to be turned off in a delayed manner according to the pre-configured delayed turn-off parameters, thereby realizing the modulation process at the receiving end.

[0050] Optionally, in this embodiment of the present disclosure, the above-mentioned delayed turn-off parameter is configured to characterize the delay duration of the delayed turn-off of the lower MOSFET; in the above step S306, when controlling the delayed turn-off of the lower MOSFET, the lower MOSFET can be controlled to remain in the conducting state in response to the switching of the operating state of the lower MOSFET from the conducting state to the turning-off state; then the holding duration of the conducting state is recorded, and if the holding duration reaches the delay duration corresponding to the delayed turn-off parameter, the lower MOSFET is controlled to turn off.

[0051] That is, when the operating state of the MOSFET changes from the on state to the off state under the control of the rectification logic, based on the delay turn-off parameter, the lower MOSFET that needs to be turned off will continue to be turned on until the duration of being turned on reaches the delay duration corresponding to the delay turn-off parameter, and then the lower MOSFET will be turned off.

[0052] Since the lower MOSFET that needs to be turned off remains on, based on the rectification logic described above, the other lower MOSFET in the rectifier circuit will turn on. That is, within the delay time corresponding to the delayed turn-off parameter, both lower MOSFETs in the rectifier circuit (the first and second lower MOSFETs in Figure 2) are on, resulting in a brief short circuit between the two lower MOSFETs. This leads to an increase in the current flowing through the lower MOSFETs. By monitoring the current flowing through the lower MOSFETs, load modulation can be achieved. Therefore, this embodiment of the present disclosure also includes the following process:

[0053] The current parameters of the MOSFET during the delayed turn-off phase are monitored. For example, the current flowing through the MOSFET is sampled and monitored, and then a modulation signal is generated based on the current parameters. The modulation signal is then sent to the transmitter to realize communication between the transmitter and the receiver.

[0054] Furthermore, the aforementioned delay duration can be configured. For example, by increasing or decreasing the delay duration while maintaining the modulation signal strength, flexible control of different modulation depths can be achieved, thereby causing a phase change in the resonant current of the receiver's resonant cavity relative to the driving switch voltage of the receiver. The specific control of the modulation depth depends on the actual application, and this disclosure does not impose any limitations on it.

[0055] In practical use, considering that there are two lower MOSFETs in the above rectifier circuit, namely the first lower MOSFET and the second lower MOSFET in Figure 2, the specific step S304 is to monitor the operating status of the first lower MOSFET and the second lower MOSFET during the operation of the rectifier circuit.

[0056] Furthermore, when the MOSFET is turned off under control with a delay, in response to the switching of the operating state of the first lower MOSFET from the on state to the off state, the first lower MOSFET can be kept in the on state, and the first upper MOSFET can be kept in the off state, while the second upper MOSFET is turned off and the second lower MOSFET is turned on; or, in response to the switching of the operating state of the second lower MOSFET from the on state to the off state, the second lower MOSFET can be kept in the on state, and the second upper MOSFET can be kept in the off state, while the first upper MOSFET is turned off and the first lower MOSFET is turned on.

[0057] That is, based on the rectification logic, while implementing delayed turn-off control for the lower MOSFET, the upper MOSFET that needs to be turned on is also controlled with a time delay to avoid short circuits caused by the simultaneous turn-on of the upper and lower MOSFETs on the same path.

[0058] To facilitate understanding, in addition to the schematic diagram of the wireless charging system shown in Figure 2, Figure 4 also shows a schematic diagram of the signal path to illustrate the modulation process.

[0059] Optionally, the energy coupled from the transmitting coil to the receiving coil L1 is actually an alternating current signal. Therefore, in the rectifier circuit, the first upper MOSFET M1, the second upper MOSFET M2, the first lower MOSFET M3, and the second lower MOSFET M4 are alternately turned on. That is, while the first upper MOSFET M1 and the second lower MOSFET M4 are turned on, the second upper MOSFET M2 and the first lower MOSFET M3 are turned off. Similarly, while the first upper MOSFET M1 and the second lower MOSFET M4 are turned off, the second upper MOSFET M2 and the first lower MOSFET M3 are turned on.

[0060] Assuming that during rectification within one signal cycle, the first upper MOSFET M1 and the second lower MOSFET M4 are turned on first, while the second upper MOSFET M2 and the first lower MOSFET M3 are turned off. The rectified signal path is shown by the solid arrow in Figure 4. When the AC signal coupled from the transmitter undergoes commutation, to achieve signal rectification, according to the rectification logic, the first upper MOSFET M1 and the second lower MOSFET M4 will be turned off, while the second upper MOSFET M2 and the first lower MOSFET M3 will be turned on.

[0061] However, in this embodiment, due to the presence of a modulation mechanism, the operating state of the lower MOSFET is monitored during the operation of the rectifier circuit. Specifically, when the operating state of the second lower MOSFET M4 changes from the on state to the off state, based on the modulation mechanism, the second lower MOSFET M4 is controlled to delay its turn-off, i.e., enter a modulation state. In this state, the first lower MOSFET M3 will conduct normally according to the rectification logic, the first upper MOSFET M1 will be normally turned off according to the rectification logic, and the second upper MOSFET M2 will be delayed based on the modulation mechanism. The modulation mechanism delays the turn-on, meaning that the second upper MOSFET M2 remains off. At this time, the first upper MOSFET M1 and the second upper MOSFET M2 will be off in the rectifier circuit, while the first lower MOSFET M3 and the second lower MOSFET M4 will be on. At this time, the receiving coil L1, the first lower MOSFET M3 and the second lower MOSFET M4 will form a path, as shown by the dashed arrow in Figure 4. That is, the two lower MOSFETs will experience a brief short circuit, which will increase the current flowing through the lower MOSFETs, thereby forming the modulation state in this embodiment.

[0062] The duration of this modulation state is determined by the delay-off parameter.

[0063] When the duration of the modulation state is detected to reach the delay time corresponding to the above-mentioned delay turn-off parameter, the normal rectification state is entered, that is, the second lower MOSFET M4 is turned off, and the second upper MOSFET M2 is turned on. Thus, one modulation cycle is completed.

[0064] Similarly, when the next AC signal is switched, the next modulation signal can be obtained by repeating this process until the entire charging process is completed.

[0065] Furthermore, for ease of understanding, Figure 5 also shows a schematic diagram of a modulation signal. As shown in Figure 5, it specifically illustrates the modulation signal monitored at the transmitting end based on the above-described modulation method according to the embodiments of this disclosure, such as the signal obtained after phase demodulation of the current of the transmitting end coil and low-pass filtering, and the change of the signal over time.

[0066] In Figure 5, signal A1 is the signal after modulation, and signal A2 is the signal before modulation, i.e., the signal under normal rectification state. As can be seen from Figure 5, signal A1 has obvious jumps. That is, the modulation method provided in this embodiment generates significant modulation current in the resonant cavity. These modulation currents can cause obvious phase changes in the resonant cavity current at the transmitting end. Therefore, the above-mentioned modulation method in this embodiment can achieve equivalent load modulation effect, which not only saves material costs but also improves the adjustment flexibility of modulation depth to adapt to diverse application needs.

[0067] In addition, the above-mentioned receiving end is also equipped with a rectifier drive circuit. The rectifier drive circuit is provided with a control interface corresponding to each MOS transistor. The control interface is connected to the control terminal of the corresponding MOS transistor. For example, the gates G1, G2, G3, and G4 of each MOS transistor in Figure 2 have corresponding control interfaces. The MOS transistor is turned on and off by controlling the gate.

[0068] Therefore, based on the above-mentioned rectifier drive circuit, when the rectifier circuit is controlled to run according to the pre-configured rectifier logic, the rectifier drive circuit can be controlled to generate control signals for the first upper MOSFET, the second lower MOSFET, the second upper MOSFET, and the first lower MOSFET according to the rectifier logic; the control signals are output through the control interface to control the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET, the first lower MOSFET to conduct alternately. Moreover, the process of delaying the turn-off of the lower MOSFET can also be realized by the rectifier drive circuit, such as continuously controlling the first lower MOSFET or turning on the second lower MOSFET during the delay period, etc.

[0069] The specific rectifier drive circuit is also connected to the controller, that is, under the drive of the controller, control signals are generated according to the rectification logic to control the on and off states of each MOSFET. The specific rectifier drive circuit depends on the actual use case, and this disclosure embodiment does not limit it.

[0070] Furthermore, based on the above embodiments, this disclosure also provides a modulation device for a wireless charging system, applied to a wireless charging system, the wireless charging system including a transmitter and a receiver, the receiver including a receiver coil, and a rectifier circuit connected to the receiver coil, the rectifier circuit being a circuit based on MOS transistors;

[0071] Figure 6 shows a structural block diagram of a modulation device for a wireless charging system. The device includes:

[0072] The rectifier module 50 is configured to respond to the start of the wireless charging system and control the operation of the rectifier circuit according to the pre-configured rectifier logic to rectify the energy coupled by the receiving coil.

[0073] The monitoring module 52 is configured to monitor the operating status of the lower MOSFET during the operation of the rectifier circuit; wherein the lower MOSFET is the MOSFET in the rectifier circuit that is closest to the ground terminal;

[0074] The modulation module 54 is configured to control the lower MOSFET to turn off in a delayed manner according to a pre-configured delayed turn-off parameter if it detects that the operating state of the lower MOSFET has switched from the on state to the off state.

[0075] Furthermore, this disclosure also provides a wireless charging system, which includes a transmitter and a receiver, wherein the controller of the receiver is configured with the modulation device of the wireless charging system described above.

[0076] Optionally, the receiver also includes a receiver coil and a rectifier circuit connected to the receiver coil, the rectifier circuit being a circuit based on a MOSFET; the rectifier circuit is connected to the controller.

[0077] Optionally, the wireless charging system provided in this embodiment can be referenced to the schematic diagram shown in FIG2, that is, the rectifier circuit includes a first upper MOSFET, a second upper MOSFET, a first lower MOSFET, and a second lower MOSFET; wherein, the first end of the first upper MOSFET is connected to a power supply pin, the second end of the first upper MOSFET is connected to the first end of the first lower MOSFET, and the second end of the first lower MOSFET is grounded; the first end of the second upper MOSFET is connected to a power supply pin, the second end of the second upper MOSFET is connected to the first end of the second lower MOSFET, and the second end of the second lower MOSFET is grounded; one end of the receiving coil is connected to the connection path of the first upper MOSFET and the first lower MOSFET, and the other end of the receiving coil is connected to the connection path of the second upper MOSFET and the second lower MOSFET; the receiving end is also configured with a rectifier drive circuit, the rectifier drive circuit is provided with a control interface corresponding to each MOSFET; the control interface is connected to the control terminal of the corresponding MOSFET.

[0078] The wireless charging system and modulation device for the wireless charging system provided in this disclosure have the same technical features as the modulation method for the wireless charging system provided in the above embodiments, so they can also solve the same technical problems and achieve the same technical effects.

[0079] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the wireless charging system and the modulation device of the wireless charging system described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0080] The modulation method, apparatus, and computer program product of the wireless charging system provided in this disclosure include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation details, please refer to the method embodiments, which will not be repeated here.

[0081] Furthermore, in the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0082] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0083] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are configured for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0084] Finally, it should be noted that the above embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure. Such modifications, changes, 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 disclosure, and should all be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims. Industrial applicability

[0085] The modulation method, apparatus, and wireless charging system provided in this disclosure can achieve load modulation effect at the receiving end of the wireless charging system without increasing material costs.

Claims

1. A modulation method for a wireless charging system, characterized in that, The invention relates to a wireless charging system, which includes a transmitter and a receiver. The receiver includes a receiver coil and a rectifier circuit connected to the receiver coil. The rectifier circuit is a circuit based on a MOSFET. The method includes: In response to the activation of the wireless charging system, the rectifier circuit is controlled to operate according to the pre-configured rectifier logic to rectify the energy coupled by the receiving coil. The operating status of the lower MOSFET is monitored during the operation of the rectifier circuit; wherein, the lower MOSFET is the MOSFET in the rectifier circuit that is closest to the ground terminal; If the operating state of the lower MOSFET is detected to switch from the on state to the off state, the lower MOSFET is controlled to be turned off with a delay according to the pre-configured delay turn-off parameters.

2. The method according to claim 1, characterized in that, The delayed turn-off parameter is used to characterize the delay duration of the delayed turn-off of the lower MOS transistor; The steps of controlling the delayed turn-off of the lower MOSFET according to the pre-configured delayed turn-off parameters include: In response to the switching of the operating state of the lower MOSFET from the on state to the off state, the lower MOSFET is controlled to maintain the on state; Record the duration of the on-state. If the duration of the on-state reaches the delay duration corresponding to the delay turn-off parameter, then control the lower MOS transistor to turn off.

3. The method according to claim 1, characterized in that, The method further includes: Monitor the current parameters of the lower MOSFET during the delayed turn-off phase; A modulation signal is generated based on the current parameters, and the modulation signal is sent to the transmitting end.

4. The method according to claim 2, characterized in that, The rectifier circuit includes a first upper MOSFET, a second upper MOSFET, a first lower MOSFET, and a second lower MOSFET; Wherein, the first terminal of the first upper MOSFET is connected to the power supply pin, the second terminal of the first upper MOSFET is connected to the first terminal of the first lower MOSFET, and the second terminal of the first lower MOSFET is grounded; The first terminal of the second upper MOSFET is connected to the power supply pin, the second terminal of the second upper MOSFET is connected to the first terminal of the second lower MOSFET, and the second terminal of the second lower MOSFET is grounded. One end of the receiving coil is connected to the connection path between the first upper MOSFET and the first lower MOSFET, and the other end of the receiving coil is connected to the connection path between the second upper MOSFET and the second lower MOSFET. The step of controlling the rectifier circuit to operate according to pre-configured rectifier logic to rectify the energy coupled from the receiving coil includes: The first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET are alternately turned on according to the pre-configured rectification logic to rectify the energy coupled by the receiving coil.

5. The method according to claim 4, characterized in that, The steps for monitoring the operating status of the lower MOSFET during the operation of the rectifier circuit include: The operating status of the first lower MOSFET and the second lower MOSFET is monitored during the operation of the rectifier circuit.

6. The method according to claim 5, characterized in that, The step of controlling the lower MOSFET to maintain the on state in response to the switching of the operating state of the lower MOSFET from the on state to the off state includes: In response to the switching of the operating state of the first lower MOSFET from the on state to the off state, the first lower MOSFET is controlled to remain in the on state, and the first upper MOSFET is controlled to remain in the off state; and, Control the second upper MOSFET to turn off and control the second lower MOSFET to turn on; or, In response to the switching of the operating state of the second lower MOSFET from the on state to the off state, the second lower MOSFET is controlled to remain in the on state, and the second upper MOSFET is controlled to remain in the off state; and, Control the first upper MOSFET to turn off and control the first lower MOSFET to turn on.

7. The method according to claim 4, characterized in that, The receiving end is also equipped with a rectifier drive circuit, which has a control interface corresponding to each MOS transistor; the control interface is connected to the control terminal of the corresponding MOS transistor. The steps of controlling the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET to conduct alternately according to the pre-configured rectification logic include: The rectifier drive circuit is controlled to generate control signals for the first upper MOSFET, the second lower MOSFET, the second upper MOSFET, and the first lower MOSFET according to the rectification logic; The control signal is output through the control interface to control the first upper MOSFET, the second lower MOSFET, and the second upper MOSFET and the first lower MOSFET to conduct alternately.

8. A modulation device for a wireless charging system, characterized in that, The invention relates to a wireless charging system, which includes a transmitter and a receiver. The receiver includes a receiver coil and a rectifier circuit connected to the receiver coil. The rectifier circuit is a circuit based on a MOSFET. The device includes: The rectifier module is configured to respond to the start of the wireless charging system and control the operation of the rectifier circuit according to the pre-configured rectifier logic to rectify the energy coupled by the receiving coil. The monitoring module is configured to monitor the operating status of the lower MOSFET during the operation of the rectifier circuit; wherein the lower MOSFET is the MOSFET in the rectifier circuit that is closest to the ground terminal; The modulation module is configured to control the lower MOSFET to turn off with a delay according to a pre-configured delay turn-off parameter if it detects that the operating state of the lower MOSFET has switched from the on state to the off state.

9. A wireless charging system, characterized in that, The wireless charging system includes a transmitter and a receiver, and the controller of the receiver is configured with a modulation device of the wireless charging system as described in claim 8. The receiving end also includes a receiving end coil and a rectifier circuit connected to the receiving end coil, the rectifier circuit being a circuit based on a MOS transistor. The rectifier circuit is connected to the controller.

10. The wireless charging system according to claim 9, characterized in that, The rectifier circuit includes a first upper MOSFET, a second upper MOSFET, a first lower MOSFET, and a second lower MOSFET; Wherein, the first terminal of the first upper MOSFET is connected to the power supply pin, the second terminal of the first upper MOSFET is connected to the first terminal of the first lower MOSFET, and the second terminal of the first lower MOSFET is grounded; The first terminal of the second upper MOSFET is connected to the power supply pin, the second terminal of the second upper MOSFET is connected to the first terminal of the second lower MOSFET, and the second terminal of the second lower MOSFET is grounded. One end of the receiving coil is connected to the connection path between the first upper MOSFET and the first lower MOSFET, and the other end of the receiving coil is connected to the connection path between the second upper MOSFET and the second lower MOSFET. The receiving end is also equipped with a rectifier drive circuit, which has a control interface corresponding to each MOS transistor; the control interface is connected to the control terminal of the corresponding MOS transistor.

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