Wireless charging receiver, method, chip and electronic equipment

Abstract

The invention provides a wireless charging receiver, a wireless charging method, a chip and electronic equipment, and relates to the technical field of wireless charging. The wireless charging receiver for identifying whether there is a magnetic accessory coupled to the wireless charging receiver includes a receiving circuit. When free oscillation is generated, the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is smaller than the first preset frequency. Therefore, the magnitude of the free oscillation current of the receiving circuit can be influenced by the existence of the magnetic accessory, so that the voltage of the receiving coil can be changed. Therefore, the receiving circuit detects the voltage of the receiving coil in the receiving circuit, and obtains a Q value detection result according to the voltage of the receiving coil, so as to determine whether the magnetic accessory is coupled with the wireless charging receiver or not. Therefore, a Hall device does not need to be arranged in the receiving circuit, the cost of the receiving circuit can be reduced, and large area and space of a circuit board of the receiving circuit are prevented from being occupied.

Description

Technical Field

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

[0002] The principle of wireless charging technology is to wirelessly transmit electrical energy through electromagnetic field coupling between a transmitting coil in the transmitter (TX) circuit and a receiving coil in the receiver (RX) circuit. For example, in a mobile phone wireless charger, the phone is the RX circuit, the wireless charger is the TX circuit, the transmitting coil is located in the wireless charger, and the receiving coil is located inside the phone. Because wireless charging relies on the alignment of the transmitting and receiving coils, traditional wireless chargers cannot achieve optimal charging simply by placing them. If placed crooked, they will suffer from low wireless charging efficiency, slow charging, and severe heat generation. This is why magnetic charging technology has been developed. However, some electronic devices cannot directly support magnetic charging technology, so magnetic accessories have been developed. Magnetic accessories are portable accessories for electronic devices such as smartphones and tablets. Users simply attach the electronic device equipped with the magnetic accessory to the wireless charger to charge it.

[0003] In related technologies, a Hall effect device is typically installed inside the RX. This allows the RX to identify whether a magnetic accessory is placed on it through Hall effect detection, enabling the RX to adjust the maximum charging power and / or prevent charging interruptions.

[0004] However, in the related art, the RX requires a Hall device, which results in a high cost of the RX and occupies a large area and space of the RX circuit board. Summary of the Invention

[0005] The present application provides a wireless charging receiver, method, chip, and electronic device, which can reduce the cost of RX and avoid occupying a large area and space of the RX circuit board.

[0006] In a first aspect, the present application provides a wireless charging receiver for identifying whether a magnetic accessory is coupled to the wireless charging receiver, the wireless charging receiver comprising: a receiving circuit;

[0007] The receiving circuit is used to detect the voltage of the receiving coil in the receiving circuit when free oscillation is generated, and obtain a Q value detection result based on the voltage of the receiving coil. The Q value detection result is used to determine whether the magnetic accessory is coupled with the wireless charging receiver, wherein the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is less than a first preset frequency.

[0008] With the wireless charging receiver provided by the first aspect, when free oscillation occurs, the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is less than the first preset frequency. Therefore, the presence or absence of the magnetic accessory will affect the magnitude of the free oscillation current of the receiving circuit, causing the voltage of the receiving coil to change accordingly. In this way, the receiving circuit can detect the voltage of the receiving coil in the receiving circuit, and obtain a Q value detection result based on the voltage of the receiving coil to determine whether the magnetic accessory is coupled with the wireless charging receiver. Therefore, there is no need to set a Hall device in the receiving circuit, which can reduce the cost of the receiving circuit and avoid occupying a large area and space of the circuit board of the receiving circuit.

[0009] In one possible design, the receiving circuit includes: a resonant circuit, a synchronous rectifier bridge, and a Q-value detection result output circuit;

[0010] The input end of the synchronous rectifier bridge is used to receive the input voltage, the first output end of the synchronous rectifier bridge is electrically connected to the first end of the resonant circuit, the second output end of the synchronous rectifier bridge is electrically connected to the second end of the resonant circuit, the third end of the resonant circuit is electrically connected to the input end of the Q value detection result output circuit, and the output end of the Q value detection result output circuit is used to output the Q value detection result;

[0011] The synchronous rectifier bridge is used to control the first field effect transistor and the fourth field effect transistor in the synchronous rectifier bridge to be turned on, so as to transmit the input voltage to the resonant circuit;

[0012] The resonant circuit is configured to charge a first capacitor and a second capacitor in the resonant circuit using the input voltage until a voltage across the first capacitor reaches the input voltage;

[0013] The synchronous rectifier bridge is further configured to control the first field effect transistor to be turned off first and the second field effect transistor in the synchronous rectifier bridge to be turned on later when the voltage across the first capacitor is the input voltage, and the conduction time is preset;

[0014] The resonant circuit is further configured to start free oscillation after the second field effect transistor is turned off, so as to enable the receiving circuit to generate the free oscillation;

[0015] The Q value detection result output circuit is used to detect the voltage of the receiving coil and obtain the Q value detection result according to the voltage of the receiving coil.

[0016] In one possible design, the Q value detection result output circuit includes: a voltage divider circuit and a Q value detection circuit;

[0017] The input end of the voltage divider circuit is electrically connected to the third end of the resonant circuit, the output end of the voltage divider circuit is electrically connected to the input end of the Q value detection circuit, and the output end of the Q value detection circuit is used to output the Q value detection result;

[0018] The voltage divider circuit is used to detect the voltage of the receiving coil, obtain a detection voltage, and transmit the detection voltage to the Q value detection circuit;

[0019] The Q value detection circuit is used to calculate the Q value detection result according to the detection voltage.

[0020] In one possible design, the voltage divider circuit includes: a first resistor and a second resistor;

[0021] The first end of the first resistor is electrically connected to the third end of the resonant circuit, the second end of the first resistor is electrically connected to the first end of the second resistor, the input end of the Q value detection circuit is electrically connected between the second end of the first resistor and the first end of the second resistor, and the second end of the second resistor is grounded.

[0022] In one possible design, the resonant circuit includes: a first capacitor, a second capacitor, and a receiving coil;

[0023] The first plate of the first capacitor and the first plate of the second capacitor are both electrically connected to the first output end of the synchronous rectifier bridge, the second plate of the first capacitor is respectively electrically connected to the first end of the receiving coil and the input end of the Q-value detection result output circuit, and the second end of the receiving coil is respectively electrically connected to the second plate of the second capacitor and the second output end of the synchronous rectifier bridge.

[0024] In one possible design, the synchronous rectifier bridge includes: a first field effect transistor, a second field effect transistor, a third field effect transistor, and a fourth field effect transistor;

[0025] The first end of the first field effect transistor and the first end of the third field effect transistor are both used to access the input voltage, the second end of the first field effect transistor is electrically connected to the first end of the second field effect transistor, the first end of the resonant circuit is electrically connected between the second end of the first field effect transistor and the first end of the second field effect transistor, the second end of the third field effect transistor is electrically connected to the first end of the fourth field effect transistor, the second end of the resonant circuit is electrically connected between the second end of the third field effect transistor and the first end of the fourth field effect transistor, the control end of the first field effect transistor, the control end of the second field effect transistor, the control end of the third field effect transistor and the control end of the fourth field effect transistor are all used to access a control signal, and the control signal is used to control the conduction or shutdown of the field effect transistors. The second end of the second field effect transistor and the second end of the fourth field effect transistor are both grounded.

[0026] In one possible design, the magnetic attraction accessory includes: a first coil, a third capacitor, and a third resistor;

[0027] The first plate of the third capacitor is electrically connected to the first end of the first coil, the second plate of the third capacitor is electrically connected to the first end of the third resistor, and the second end of the third resistor is electrically connected to the second end of the first coil.

[0028] In a second aspect, the present application provides a detection method, which is performed by a wireless charging receiver in the first aspect and various possible designs of the first aspect, wherein the wireless charging receiver is used to identify whether a magnetic accessory is coupled to the wireless charging receiver, the wireless charging receiver comprising: a receiving circuit; the method comprising:

[0029] When the receiving circuit generates free oscillation, the receiving circuit detects the voltage of the receiving coil in the receiving circuit, and obtains a Q value detection result based on the voltage of the receiving coil. The Q value detection result is used to determine whether the magnetic accessory is coupled with the wireless charging receiver, wherein the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is less than a first preset frequency.

[0030] In one possible design, when the receiving circuit generates free oscillation, detecting the voltage of a receiving coil in the receiving circuit, and obtaining a Q value detection result based on the voltage of the receiving coil includes:

[0031] The synchronous rectifier bridge controls the first field effect transistor and the fourth field effect transistor in the synchronous rectifier bridge to be turned on, so as to transmit the input voltage to the resonant circuit;

[0032] The resonant circuit charges a first capacitor and a second capacitor in the resonant circuit using the input voltage until a voltage across the first capacitor reaches the input voltage;

[0033] When the voltage across the first capacitor is equal to the input voltage, the synchronous rectifier bridge controls the first field effect transistor to be turned off first, and then the second field effect transistor in the synchronous rectifier bridge is turned on for a preset time period;

[0034] The resonant circuit starts free oscillation after the second field effect transistor is turned off, so that the receiving circuit generates the free oscillation;

[0035] The Q value detection result output circuit detects the voltage of the receiving coil and obtains the Q value detection result according to the voltage of the receiving coil.

[0036] The beneficial effects of the methods provided in the above-mentioned second aspect and each possible design of the above-mentioned second aspect can be referred to the beneficial effects brought about by the above-mentioned first aspect and each possible implementation method of the first aspect, and will not be repeated here.

[0037] In a third aspect, the present application provides a foreign object detection method, which is applied to the wireless charging receiver in the first aspect and any possible design of the first aspect, and the method includes:

[0038] Based on the Q value detection result, it is determined whether there is a foreign object within the working range of the wireless charging receiver.

[0039] In a fourth aspect, the present application provides a chip, comprising the wireless charging receiver according to the first aspect and various possible designs of the first aspect.

[0040] In a fifth aspect, the present application provides an electronic device, comprising: the chip in the fourth aspect above.

[0041] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] Figure 1 A schematic structural diagram of a wireless charging receiver provided in one embodiment of the present application;

[0044] Figure 2 A schematic diagram of a detection method according to an embodiment of the present application;

[0045] Figure 3 A schematic diagram of a waveform of a voltage of a receiving coil provided in an embodiment of the present application;

[0046] Figure 4 A schematic diagram of operating waveforms of a wireless charging receiver provided in one embodiment of the present application. DETAILED DESCRIPTION

[0047] In this application, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a alone, b alone, or c alone can represent: a alone, b alone, c alone, a and b in combination, a and c in combination, b and c in combination, or a, b, and c in combination, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0048] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present application.

[0049] The terms "connected" and "connect" should be interpreted broadly. For example, "connected" or "connected" in a circuit structure can refer not only to a physical connection, but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as the circuit is interconnected. It can also refer to internal connectivity between two components. Signal connection can refer not only to signal connection through circuits but also to signal connection through media, such as radio waves. Those skilled in the art will understand the specific meanings of the above terms in this application on a case-by-case basis.

[0050] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of a wireless charging receiver provided in one embodiment of the present application. Figure 1 As shown, the wireless charging receiver 1000 may include: a receiving circuit 100 .

[0051] Below, refer to Figure 2 , Figure 2 A flow chart of a detection method provided in one embodiment of the present application.

[0052] S101 , when the receiving circuit generates free oscillation, the receiving circuit detects the voltage of the receiving coil in the receiving circuit, and obtains a Q value detection result according to the voltage of the receiving coil.

[0053] The Q value detection result is used to determine whether the magnetic accessory 200 is coupled with the wireless charging receiver 1000 .

[0054] The magnetic accessories 200 may include: a magnetic back clip, a magnetic phone case, a magnetic patch, and a magnetic finger ring buckle. In other words, the magnetic accessories 200 may be presented in various forms such as a magnetic back clip, a magnetic phone case, a magnetic patch, and a magnetic finger ring buckle.

[0055] The frequency difference between the free oscillation frequency of the receiving circuit 100 and the free oscillation frequency of the magnetic accessory 200 is smaller than the first preset frequency.

[0056] The capacitance value of the third capacitor C in the magnetic accessory 200 is smaller than the preset capacitance value, and the inductance value of the first coil L is smaller than the preset inductance value.

[0057] The capacitance of the third capacitor C is smaller than the preset capacitance, which means that the third capacitor C is a small capacitor. The inductance of the first coil L is smaller than the preset inductance, which means that the first coil L is a small coil.

[0058] The preset capacitance value is in the order of nF. The preset inductance value is related to the preset capacitance value and the free oscillation frequency of the magnetic accessory 200. For example, when the preset capacitance value is in the order of nF and the free oscillation frequency of the magnetic accessory 200 is 1 MHz, the preset inductance value is in the order of μH.

[0059] Since the frequency difference between the free oscillation frequency of the receiving circuit 100 and the free oscillation frequency of the magnetic accessory 200 is less than the first predetermined frequency, a Hall effect device is not required in the receiving circuit 100, thereby reducing the cost of the receiving circuit 100 and avoiding occupying a large area and space on the PCB of the receiving circuit 100.

[0060] When free oscillation is generated, the receiving circuit 100 can detect the voltage Vtank of the receiving coil Coil in the receiving circuit 100. Furthermore, the receiving circuit 100 can obtain a Q value detection result based on the voltage Vtank of the receiving coil Coil.

[0061] The Q value test result is used to determine whether the magnetic accessory 200 is coupled to the wireless charging receiver 1000. When the Q value test result is small, it indicates that the magnetic accessory 200 is present, that is, the magnetic accessory 200 is coupled to the wireless charging receiver 1000. When the Q value test result is large, it indicates that the magnetic accessory 200 is not present, that is, the magnetic accessory 200 is not coupled to the wireless charging receiver 1000.

[0062] The frequency difference between the free oscillation frequency of the receiving circuit 100 and the free oscillation frequency of the magnetic accessory 200 is less than the first preset frequency. In other words, the free oscillation frequency of the receiving circuit 100 and the free oscillation frequency of the magnetic accessory 200 are close.

[0063] The free oscillation frequency of the magnetic accessory 200 is, for example, 1 MHz, which is significantly different from the wireless charging switching frequency of the receiving circuit 100, which is 110 kHz to 205 kHz. Therefore, during the wireless charging power transmission process, the losses generated by the magnetic accessory 200 are small and negligible. In other words, the losses generated by the magnetic accessory 200 have little impact on power transmission.

[0064] The following combination Figure 3 , Figure 3 This is a waveform diagram of the voltage of the receiving coil provided in an embodiment of the present application, which details the change of the voltage Vtank of the receiving coil Coil corresponding to the presence and absence of the magnetic accessory 200.

[0065] like Figure 3 As shown in Figure a, when magnetic accessory 200 is present, that is, when magnetic accessory 200 is coupled to wireless charging receiver 1000, the free oscillation frequency of receiving circuit 100 approaches that of magnetic accessory 200, causing losses in magnetic accessory 200. This causes the free oscillation current in receiving circuit 100 to decay more rapidly, causing the voltage Vtank of receiving coil Coil to decay more quickly, resulting in a smaller Q-value detection result. Consequently, receiving circuit 100 adjusts its charging strategy to prevent charging interruptions when magnetic accessory 200 is present.

[0066] In addition, when the free oscillation frequency of the receiving circuit 100 is equal to the free oscillation frequency of the magnetic accessory 200, the magnetic accessory 200 generates the greatest loss, causing the free oscillation current of the receiving circuit 100 to decay fastest, and the voltage Vtank of the receiving coil Coil to decay fastest.

[0067] like Figure 3 As shown in Figure b, when the magnetic accessory 200 is absent—that is, when the magnetic accessory 200 is uncoupled from the wireless charging receiver 1000—the magnetic accessory 200 generates no losses. Consequently, the free-running current in the receiving circuit 100 decays more slowly, causing the voltage Vtank of the receiving coil Coil to decay more slowly, resulting in a larger Q-value detection result. Consequently, the receiving circuit 100 adjusts its charging strategy to prevent charging interruptions when the magnetic accessory 200 is absent.

[0068] The wireless charging receiver, method, chip and electronic device provided by the present application, when generating free oscillation, the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is less than the first preset frequency. Therefore, the presence or absence of the magnetic accessory will affect the magnitude of the free oscillation current of the receiving circuit, causing the voltage of the receiving coil to change accordingly. In this way, the receiving circuit can detect the voltage of the receiving coil in the receiving circuit, and obtain the Q value detection result based on the voltage of the receiving coil to determine the coupling between the magnetic accessory and the wireless charging receiver. Therefore, there is no need to set a Hall device in the receiving circuit, which can reduce the cost of the receiving circuit and avoid occupying a large area and space of the circuit board of the receiving circuit.

[0069] Based on the description of the above embodiment, a possible implementation of the receiving circuit 100 is exemplified. Figure 1 As shown, the receiving circuit 100 may include: a resonant circuit 120 , a synchronous rectifier bridge 110 and a Q-value detection result output circuit 130 .

[0070] The input end of the synchronous rectifier bridge 110 is used to connect to the input voltage Vrect, the first output end of the synchronous rectifier bridge 110 is electrically connected to the first end of the resonant circuit 120, the second output end of the synchronous rectifier bridge 110 is electrically connected to the second end of the resonant circuit 120, the third end of the resonant circuit 120 is electrically connected to the input end of the Q value detection result output circuit 130, and the output end of the Q value detection result output circuit 130 is used to output the Q value detection result.

[0071] Among them, the resonant circuit 120, the synchronous rectifier bridge 110 and the Q-value detection result output circuit 130 can be set separately or integrated, and the embodiment of the present application does not make specific limitations on this.

[0072] The synchronous rectifier bridge 110 can control the first field effect transistor Q1 and the fourth field effect transistor Q4 in the synchronous rectifier bridge 110 to be turned on, so that the synchronous rectifier bridge 110 can transmit the input voltage Vrect to the resonant circuit 120 .

[0073] In this way, the resonant circuit 120 can use the input voltage Vrect to charge the first capacitor Cs and the second capacitor Cd in the resonant circuit 120 until the voltage across the first capacitor Cs reaches the input voltage Vrect. The second capacitor Cd is charged to the input voltage Vrect faster than the first capacitor Cs.

[0074] The first capacitor Cs has a larger capacitance, and the second capacitor Cd has a smaller capacitance.

[0075] When the voltage across the first capacitor Cs reaches the input voltage Vrect, the synchronous rectifier bridge 110 can control the first field-effect transistor Q1 to turn off first, and then turn on the second field-effect transistor Q2 in the synchronous rectifier bridge 110 for a preset duration, so that both the first capacitor Cs and the second capacitor Cd are in a discharged state. Due to the presence of the receiving coil Coil, the first capacitor Cs discharges very quickly. As a result, within the preset duration, the voltage on the second capacitor Cd is quickly released, even to zero, while the voltage on the first capacitor Cs remains almost unchanged, resulting in a voltage difference between the second capacitor Cd and the first capacitor that is greater than a certain amplitude.

[0076] The preset time duration is relatively short, that is, the time during which the second field effect transistor Q2 is turned on is relatively short.

[0077] Furthermore, after the second field effect transistor Q2 is turned off, the resonant circuit 120 starts to free oscillate, causing the receiving circuit 100 to generate free oscillation.

[0078] Thus, the Q value detection result output circuit 130 can detect the voltage Vtank of the receiving coil Coil. Furthermore, the Q value detection result output circuit 130 can obtain a Q value detection result based on the voltage Vtank of the receiving coil Coil, so that the receiving circuit 100 can obtain the Q value detection result.

[0079] In summary, the synchronous rectifier bridge can control the first and fourth field-effect transistors in the synchronous rectifier bridge to conduct to transmit the input voltage to the resonant circuit. In this way, the resonant circuit can use the input voltage to charge the first and second capacitors in the resonant circuit until the voltage across the first capacitor reaches the input voltage. When the voltage across the first capacitor reaches the input voltage, the synchronous rectifier bridge can control the first field-effect transistor to turn off first, and then turn on the second field-effect transistor in the synchronous rectifier bridge for a preset duration, so that a voltage difference exists between the first and second capacitors. Furthermore, after the second field-effect transistor turns off, the resonant circuit begins to oscillate freely, causing the receiving circuit to generate free oscillation. Thus, the Q-value detection result output circuit can detect the voltage of the receiving coil and obtain a Q-value detection result based on the voltage of the receiving coil, so that the receiving circuit can obtain the Q-value detection result.

[0080] Based on the description of the above embodiment, a possible implementation of the Q value detection result output circuit 130 is exemplified. Figure 1 As shown, the Q value detection result output circuit 130 may include: a voltage divider circuit 131 and a Q value detection circuit 132 .

[0081] The input end of the voltage divider circuit 131 is electrically connected to the third end of the resonant circuit 120 , the output end of the voltage divider circuit 131 is electrically connected to the input end of the Q value detection circuit 132 , and the output end of the Q value detection circuit 132 is used to output the Q value detection result.

[0082] The input end of the voltage divider circuit 131 is the input end of the Q value detection result output circuit 130 , and the output end of the Q value detection circuit 132 is the output end of the Q value detection result output circuit 130 .

[0083] The voltage divider circuit 131 can detect the voltage Vtank of the receiving coil Coil to obtain a detection voltage QDET. Furthermore, the voltage divider circuit 131 can transmit the detection voltage QDET to the Q value detection circuit 132 so that the Q value detection circuit 132 can obtain the detection voltage QDET.

[0084] Therefore, the Q value detection circuit 132 can calculate and obtain the Q value detection result according to the detection voltage QDET, so that the Q value detection result output circuit 130 can obtain the Q value detection result.

[0085] In summary, the voltage divider circuit can detect the voltage of the receiving coil, obtain a detection voltage, and transmit the detection voltage to the Q-value detection circuit, allowing the Q-value detection circuit to obtain the detection voltage. The Q-value detection circuit can then calculate the Q-value detection result based on the detection voltage, allowing the Q-value detection result output circuit to obtain the Q-value detection result.

[0086] Based on the description of the above embodiment, a possible implementation of the voltage divider circuit 131 is exemplified. Figure 1 As shown, the voltage divider circuit 131 may include a first resistor R1 and a second resistor R2.

[0087] A first end of the first resistor R1 is electrically connected to the third end of the resonant circuit 120, a second end of the first resistor R1 is electrically connected to a first end of the second resistor R2, an input end of the Q value detection circuit 132 is electrically connected between the second end of the first resistor R1 and the first end of the second resistor R2, and a second end of the second resistor R2 is grounded.

[0088] The first end of the first resistor R1 is the input end of the voltage divider circuit 131 , and the output end of the voltage divider circuit 131 is located between the second end of the first resistor R1 and the first end of the second resistor R2 .

[0089] Based on the description of the above embodiment, a possible implementation of the resonant circuit 120 is exemplified. Figure 1 As shown, the resonant circuit 120 may include: a first capacitor Cs, a second capacitor Cd and a receiving coil Coil.

[0090] The first plate of the first capacitor Cs and the first plate of the second capacitor Cd are both electrically connected to the first output end of the synchronous rectifier bridge 110, the second plate of the first capacitor Cs is electrically connected to the first end of the receiving coil Coil and the input end of the Q value detection result output circuit 130, and the second end of the receiving coil Coil is electrically connected to the second plate of the second capacitor Cd and the second output end of the synchronous rectifier bridge 110.

[0091] Among them, the first plate of the first capacitor Cs and the first plate of the second capacitor Cd are both the first ends of the resonant circuit 120, the second end of the receiving coil Coil and the second plate of the second capacitor Cd are both the second ends of the resonant circuit 120, and the first end of the receiving coil Coil is the third end of the resonant circuit 120.

[0092] Based on the description of the above embodiment, a possible implementation of the synchronous rectifier bridge 110 is exemplified. Figure 1 As shown, the synchronous rectifier bridge 110 may include a first field effect transistor Q1 , a second field effect transistor Q2 , a third field effect transistor Q3 and a fourth field effect transistor Q4 .

[0093] The first end of the first field-effect transistor Q1 and the first end of the third field-effect transistor Q3 are both used to receive the input voltage Vrect. The second end of the first field-effect transistor Q1 is electrically connected to the first end of the second field-effect transistor Q2. The first end of the resonant circuit 120 is electrically connected between the second end of the first field-effect transistor Q1 and the first end of the second field-effect transistor Q2. The second end of the third field-effect transistor Q3 is electrically connected to the first end of the fourth field-effect transistor Q4. The second end of the resonant circuit 120 is electrically connected between the second end of the third field-effect transistor Q3 and the first end of the fourth field-effect transistor Q4. The control ends of the first field-effect transistor Q1, the second field-effect transistor Q2, the third field-effect transistor Q3, and the fourth field-effect transistor Q4 are all used to receive control signals, which are used to control the on or off of the field-effect transistors. The second end of the second field-effect transistor Q2 and the second end of the fourth field-effect transistor Q4 are both grounded.

[0094] The first output terminal of the synchronous rectifier bridge 110 is located between the second terminal of the first field effect transistor Q1 and the first terminal of the second field effect transistor Q2, and the second output terminal of the synchronous rectifier bridge 110 is located between the second terminal of the third field effect transistor Q3 and the first terminal of the fourth field effect transistor Q4.

[0095] Among them, the first field effect transistor Q1, the second field effect transistor Q2, the third field effect transistor Q3 and the fourth field effect transistor Q4 can be P-type field effect transistors PMOS or N-type field effect transistors NMOS, which is not specifically limited in the embodiment of the present application.

[0096] For example, when the first field effect transistor Q1, the second field effect transistor Q2, the third field effect transistor Q3 and the fourth field effect transistor Q4 are N-type field effect transistors NMOS, the first end of the first field effect transistor Q1, the first end of the second field effect transistor Q2, the first end of the third field effect transistor Q3 and the first end of the fourth field effect transistor Q4 are all drains of the N-type field effect transistor NMOS, the second end of the first field effect transistor Q1, the second end of the second field effect transistor Q2, the second end of the third field effect transistor Q3 and the second end of the fourth field effect transistor Q4 are all sources of the N-type field effect transistor NMOS, and the control end of the first field effect transistor Q1, the control end of the second field effect transistor Q2, the control end of the third field effect transistor Q3 and the control end of the fourth field effect transistor Q4 are all gates of the N-type field effect transistor NMOS.

[0097] For example, when the first field effect transistor Q1, the second field effect transistor Q2, the third field effect transistor Q3 and the fourth field effect transistor Q4 are P-type field effect transistors PMOS, the first end of the first field effect transistor Q1, the first end of the second field effect transistor Q2, the first end of the third field effect transistor Q3 and the first end of the fourth field effect transistor Q4 are all sources of the P-type field effect transistor PMOS, the second end of the first field effect transistor Q1, the second end of the second field effect transistor Q2, the second end of the third field effect transistor Q3 and the second end of the fourth field effect transistor Q4 are all drains of the P-type field effect transistor PMOS, and the control end of the first field effect transistor Q1, the control end of the second field effect transistor Q2, the control end of the third field effect transistor Q3 and the control end of the fourth field effect transistor Q4 are all gates of the P-type field effect transistor PMOS.

[0098] The following combination Figure 4 , Figure 4 This is a schematic diagram of operating waveforms of a wireless charging receiver provided in one embodiment of the present application, which details the operating principle of the receiving circuit 100 generating free oscillation. The content is as follows:

[0099] At time t0, the first and fourth field-effect transistors Q1 and Q4 turn on, causing the voltage at the first output terminal AC1 of the synchronous rectifier bridge 110 to rapidly rise to the input voltage Vrect. This causes the voltage Vtank of the receiving coil Coil to be charged to the input voltage Vrect via the first capacitor Cs. Simultaneously, the second capacitor Cd is rapidly charged to the input voltage Vrect.

[0100] During the period t0-t1, the input voltage Vrect gradually charges the first capacitor Cs through the first field-effect transistor Q1, the receiving coil Coil, and the fourth field-effect transistor Q4 until the voltage across the first capacitor Cs equals the input voltage Vrect. Furthermore, when there is no free-running current in the receiving coil Coil, the voltage Vtank of the receiving coil Coil returns to 0.

[0101] Before time t1, the first field effect transistor Q1 is turned off. At time t1, the second field effect transistor Q2 is turned on, causing the voltage Vtank of the receiving coil Coil to change from 0 to a negative voltage.

[0102] During the period t1-t2, since the conduction time of the second field effect transistor Q2 is relatively short, the voltage on the second capacitor Cd is released, while the voltage on the first capacitor Cs remains almost unchanged.

[0103] At time t2, the second field effect transistor Q2 is turned off, so that the resonant circuit 120 composed of the first capacitor Cs, the second capacitor Cd and the receiving coil Coil starts to oscillate freely, causing the receiving circuit 100 to oscillate freely.

[0104] Based on the description of the above embodiment, a possible implementation of the magnetic accessory 200 is exemplified. Figure 1 As shown, the magnetic accessory 200 may include: a first coil L, a third capacitor C and a third resistor R3.

[0105] The first plate of the third capacitor C is electrically connected to the first end of the first coil L, the second plate of the third capacitor C is electrically connected to the first end of the third resistor R3, and the second end of the third resistor R3 is electrically connected to the second end of the first coil L.

[0106] Since the magnetic accessory 200 includes the first coil L and the third capacitor C, a Hall device may not be provided in the receiving circuit 100 , that is, the receiving circuit 100 does not include a Hall device.

[0107] The third resistor R3 may be a parasitic resistor of the first coil L and the third capacitor C connected in series, or may be a separately configured resistor, which is not specifically limited in the embodiment of the present application.

[0108] When the resonant circuit 120 is in free oscillation, the free oscillating current generates an alternating magnetic field on the surface of the receiving coil Coil. If the magnetic accessory 200 is present, the free oscillation frequency of the resonant circuit 120 is close to that of the magnetic accessory 200. This coupling generates an electromotive force in the first coil L, causing the magnetic accessory 200 to generate a large coupling current. This coupling current, passing through the third resistor R3, generates losses, causing the free oscillating current in the receiving coil Coil to decay more rapidly. Consequently, the voltage Vtank across the receiving coil Coil also decays more rapidly.

[0109] The present application also provides a foreign body detection method, which comprises:

[0110] Based on the Q value detection result, it is determined whether there is a foreign object within the working range of the wireless charging receiver.

[0111] The introduction of foreign matter (here, the foreign matter is a metal conductor) changes the Q value of the receiving circuit 100. Therefore, people have invented a method for determining whether a foreign matter exists by detecting the change in the Q value.

[0112] The second capacitor Cd has a relatively small capacitance, which reduces the free oscillation current of the receiving coil Coil. This reduces the eddy current loss of the receiving coil Coil caused by foreign matter, which reduces the Q value attenuation of the receiving circuit 100.

[0113] Among them, the degree of Q value attenuation caused by foreign matter is far less than the degree of Q value attenuation caused by the magnetic accessory 200.

[0114] The foreign object detection method provided in the embodiment of the present application has the same beneficial effects as the wireless charging receiver provided in the embodiment of the present application, and will not be described in detail here.

[0115] An embodiment of the present application also provides a chip, including: a wireless charging receiver.

[0116] The wireless charging receiver can be a chip or a circuit module.

[0117] The chip provided in the embodiment of the present application has the same beneficial effects as the wireless charging receiver provided in the embodiment of the present application, and will not be described in detail here.

[0118] An embodiment of the present application also provides an electronic device, including: a chip.

[0119] In this application, electronic devices may include but are not limited to: tablet computers, mobile phones and phone watches.

[0120] The electronic device provided in the embodiment of the present application has the same beneficial effects as the chip provided in the embodiment of the present application, which will not be repeated here.

[0121] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A wireless charging receiver for identifying whether a magnetic accessory is coupled to the wireless charging receiver, characterized in that: The wireless charging receiver includes: a receiving circuit; The receiving circuit is used to detect the voltage of the receiving coil in the receiving circuit when free oscillation is generated, and obtain a Q value detection result based on the voltage of the receiving coil. The Q value detection result is used to determine whether the magnetic accessory is coupled with the wireless charging receiver, wherein the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is less than a first preset frequency.

2. The wireless charging receiver according to claim 1, wherein: The receiving circuit includes: a resonant circuit, a synchronous rectifier bridge and a Q value detection result output circuit; The input end of the synchronous rectifier bridge is used to receive the input voltage, the first output end of the synchronous rectifier bridge is electrically connected to the first end of the resonant circuit, the second output end of the synchronous rectifier bridge is electrically connected to the second end of the resonant circuit, the third end of the resonant circuit is electrically connected to the input end of the Q value detection result output circuit, and the output end of the Q value detection result output circuit is used to output the Q value detection result; The synchronous rectifier bridge is used to control the first field effect transistor and the fourth field effect transistor in the synchronous rectifier bridge to be turned on, so as to transmit the input voltage to the resonant circuit; The resonant circuit is configured to charge a first capacitor and a second capacitor in the resonant circuit using the input voltage until a voltage across the first capacitor reaches the input voltage; The synchronous rectifier bridge is further configured to control the first field effect transistor to be turned off first and the second field effect transistor in the synchronous rectifier bridge to be turned on later when the voltage across the first capacitor is the input voltage, and the conduction time is preset; The resonant circuit is further configured to start free oscillation after the second field effect transistor is turned off, so as to enable the receiving circuit to generate the free oscillation; The Q value detection result output circuit is used to detect the voltage of the receiving coil and obtain the Q value detection result according to the voltage of the receiving coil.

3. The wireless charging receiver according to claim 2, wherein: The Q value detection result output circuit includes: a voltage divider circuit and a Q value detection circuit; The input end of the voltage divider circuit is electrically connected to the third end of the resonant circuit, the output end of the voltage divider circuit is electrically connected to the input end of the Q value detection circuit, and the output end of the Q value detection circuit is used to output the Q value detection result; The voltage divider circuit is used to detect the voltage of the receiving coil, obtain a detection voltage, and transmit the detection voltage to the Q value detection circuit; The Q value detection circuit is used to calculate the Q value detection result according to the detection voltage.

4. The wireless charging receiver according to claim 3, wherein: The voltage divider circuit includes: a first resistor and a second resistor; The first end of the first resistor is electrically connected to the third end of the resonant circuit, the second end of the first resistor is electrically connected to the first end of the second resistor, the input end of the Q value detection circuit is electrically connected between the second end of the first resistor and the first end of the second resistor, and the second end of the second resistor is grounded.

5. The wireless charging receiver according to claim 2, wherein: The resonant circuit includes: a first capacitor, a second capacitor and a receiving coil; The first plate of the first capacitor and the first plate of the second capacitor are both electrically connected to the first output end of the synchronous rectifier bridge, the second plate of the first capacitor is respectively electrically connected to the first end of the receiving coil and the input end of the Q-value detection result output circuit, and the second end of the receiving coil is respectively electrically connected to the second plate of the second capacitor and the second output end of the synchronous rectifier bridge.

6. The wireless charging receiver according to claim 2, wherein: The synchronous rectifier bridge comprises: a first field effect transistor, a second field effect transistor, a third field effect transistor and a fourth field effect transistor; The first end of the first field effect transistor and the first end of the third field effect transistor are both used to access the input voltage, the second end of the first field effect transistor is electrically connected to the first end of the second field effect transistor, the first end of the resonant circuit is electrically connected between the second end of the first field effect transistor and the first end of the second field effect transistor, the second end of the third field effect transistor is electrically connected to the first end of the fourth field effect transistor, the second end of the resonant circuit is electrically connected between the second end of the third field effect transistor and the first end of the fourth field effect transistor, the control end of the first field effect transistor, the control end of the second field effect transistor, the control end of the third field effect transistor and the control end of the fourth field effect transistor are all used to access a control signal, and the control signal is used to control the conduction or shutdown of the field effect transistors. The second end of the second field effect transistor and the second end of the fourth field effect transistor are both grounded.

7. The wireless charging receiver according to any one of claims 1 to 6, wherein: The magnetic attraction accessory includes: a first coil, a third capacitor and a third resistor; The first plate of the third capacitor is electrically connected to the first end of the first coil, the second plate of the third capacitor is electrically connected to the first end of the third resistor, and the second end of the third resistor is electrically connected to the second end of the first coil.

8. A detection method, characterized in that: The method is performed by a wireless charging receiver, which is used to identify whether a magnetic accessory is coupled to the wireless charging receiver. The wireless charging receiver includes: a receiving circuit; the method includes: When the receiving circuit generates free oscillation, the receiving circuit detects the voltage of the receiving coil in the receiving circuit, and obtains a Q value detection result based on the voltage of the receiving coil. The Q value detection result is used to determine whether the magnetic accessory is coupled with the wireless charging receiver, wherein the frequency difference between the free oscillation frequency of the receiving circuit and the free oscillation frequency of the magnetic accessory is less than a first preset frequency.

9. The detection method according to claim 8, characterized in that When the receiving circuit generates free oscillation, detecting the voltage of the receiving coil in the receiving circuit, and obtaining a Q value detection result according to the voltage of the receiving coil includes: The synchronous rectifier bridge controls the first field effect transistor and the fourth field effect transistor in the synchronous rectifier bridge to be turned on, so as to transmit the input voltage to the resonant circuit; The resonant circuit charges a first capacitor and a second capacitor in the resonant circuit using the input voltage until a voltage across the first capacitor reaches the input voltage; When the voltage across the first capacitor is equal to the input voltage, the synchronous rectifier bridge controls the first field effect transistor to be turned off first, and then the second field effect transistor in the synchronous rectifier bridge is turned on for a preset time period; The resonant circuit starts free oscillation after the second field effect transistor is turned off, so that the receiving circuit generates the free oscillation; The Q value detection result output circuit detects the voltage of the receiving coil and obtains the Q value detection result according to the voltage of the receiving coil.

10. A foreign body detection method, characterized in that: The method is applied to the wireless charging receiver according to any one of claims 1 to 7, and the method includes: According to the Q value detection result, it is determined whether there is a foreign object within the working range of the wireless charging receiver.

11. A chip, characterized in that: include: The wireless charging receiver according to any one of claims 1 to 7.

12. An electronic device, characterized in that: include: The chip according to claim 11.

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