WO2022170460A1

WO2022170460A1 - Wireless charging device

Info

Publication number: WO2022170460A1
Application number: PCT/CN2021/076189
Authority: WO
Inventors: 李健雄; 汪海翔
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2021-02-09
Filing date: 2021-02-09
Publication date: 2022-08-18
Also published as: CN114128080A

Abstract

The present application discloses a wireless charging device, coupled to an antenna and a battery, for use in charging the battery according to an electric field signal received from the antenna. The wireless charging device comprises a low-frequency blocking circuit, a rectifier circuit, a charging path control circuit, a filter capacitor, an overvoltage protection circuit, a battery management circuit, a near field communication controller, and a matched filter circuit. The low-frequency blocking circuit is used for blocking low-frequency noise in the electric field signal. The rectifier circuit is used for converting the electric field signal into a direct current signal. The charging path control circuit is used for connecting or disconnecting a charging path for a battery according to a charging control signal. The filter capacitor is used for smoothing the waveform of the direct current signal when the charging path is connected. The overvoltage protection circuit is used for reducing the voltage value of the direct current signal when the voltage of the direct current signal exceeds a threshold. The battery management circuit is used for providing charging power to the battery according to the direct current signal. The near field communication controller is used for generating the charging control signal.

Description

wireless charging device

technical field

The present application relates to a wireless charging device, and more particularly, to a wireless charging device that shares an antenna with near field communication.

Background technique

As smart wearable devices and small smart devices have higher and higher requirements for product water resistance, traditional charging connectors usually cannot meet the high water resistance requirements. In addition, the efficiency of wireless charging is also improving day by day, so wireless charging has become a common charging method for smart wearable devices and small smart devices. In the process of wireless charging, it is often necessary to carry out necessary communication, which includes device anti-counterfeiting authentication, product pairing, wireless charging handshake, charging parameter monitoring and charging process monitoring, and is usually communicated through near field communication. In addition, due to the small size of smart wearable devices and small smart devices, near-field communication and wireless charging often share the same antenna coil, which is the so-called integration of wireless charging and communication, thereby reducing space requirements.

However, wireless charging needs to use a large capacitor to stabilize the waveform of the charging voltage, which will affect the matching impedance of the near field communication when sending and receiving signals through the antenna, making it difficult to improve the signal quality of the near field communication. Correspondingly, the matching impedance required for near field communication will also cause the conduction angle of the rectifier to be small, thereby reducing the efficiency of wireless charging. Since the wireless charging circuit and the near field communication circuit need to share the same circuit, there will be mutual constraints between the charging efficiency and the communication quality. How to improve the efficiency of wireless charging without affecting the near field communication in the case of sharing the antenna Quality has become a problem to be solved in this field.

SUMMARY OF THE INVENTION

One of the objectives of the present application is to disclose a wireless charging device capable of sharing an antenna with near field communication to solve the above problems.

An embodiment of the present application provides a wireless charging device coupled to an antenna and a battery for charging the battery according to an electric field signal received from the antenna. The wireless charging device includes a low frequency blocking circuit, a rectifier circuit, a charging path control circuit, a filter capacitor, an overvoltage protection circuit, a battery management circuit, a near field communication controller and a matched filter circuit. The low frequency blocking circuit is coupled to the antenna for blocking low frequency noise in the electric field signal. The rectifying circuit is coupled to the low-frequency blocking circuit for converting the electric field signal into a DC signal. The charging path control circuit is coupled to the rectifier circuit, and is used for turning on or off the charging path of the battery with the DC signal according to the charging control signal. The filter capacitor is coupled to the charging path control circuit for smoothing the waveform of the DC signal when the charging path is turned on. The overvoltage protection circuit is coupled to the filter capacitor for reducing the voltage value of the DC signal when the voltage of the DC signal exceeds a critical value. The battery management circuit is coupled to the overvoltage protection circuit for providing charging power to the battery according to the DC signal. The near field communication controller is coupled to the charging path control circuit for generating the charging control signal and the near field communication signal. The matched filter circuit is coupled to the antenna and the near field communication controller, and is used for providing impedance matching with the antenna to transmit the near field communication signal through the antenna.

The wireless charging device of the present application can share an antenna with near field communication, and can separate the paths of near field communication and wireless charging, so that the efficiency of wireless charging can be improved without affecting the quality of near field communication.

Description of drawings

FIG. 1 is a functional block diagram of a wireless charging device according to an embodiment of the present application.

FIG. 2 is another schematic diagram of the wireless charging device of FIG. 1 .

FIG. 3 is a schematic diagram of a wireless charging device according to another embodiment of the present application.

Detailed ways

The following disclosure provides various implementations, or illustrations, that can be used to implement various features of the present disclosure. Specific examples of components and configurations are described below to simplify the present disclosure. As can be appreciated, these descriptions are exemplary only, and are not intended to limit the present disclosure. For example, in the description below, forming a first feature on or over a second feature may include some embodiments in which the first and second features are in direct contact with each other; and may also include Certain embodiments may have additional components formed between the first and second features described above, such that the first and second features may not be in direct contact. Furthermore, the present disclosure may reuse reference numerals and/or reference numerals in various embodiments. Such reuse is for brevity and clarity, and does not in itself represent a relationship between the different embodiments and/or configurations discussed.

Furthermore, the use of spatially relative terms, such as "below", "below", "below", "above", "above" and the like, may be used to facilitate the description of the drawings. relationship between one component or feature shown with respect to another component or feature. These spatially relative terms are intended to encompass many different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be positioned in other orientations (eg, rotated 90 degrees or at other orientations) and these spatially relative descriptors should be interpreted accordingly.

Notwithstanding that the numerical ranges and parameters setting forth the broader scope of the application are approximations, the numerical values set forth in the specific examples have been reported as precisely as possible. Any numerical value, however, inherently contains the standard deviation resulting from individual testing methods. As used herein, "about" generally means within plus or minus 10%, 5%, 1%, or 0.5% of the actual value of a particular value or range. Alternatively, the word "about" means that the actual value lies within an acceptable standard error of the mean, as considered by one of ordinary skill in the art to which this application pertains. It should be understood that all ranges, quantities, numerical values and percentages used herein (for example, to describe material amounts, time durations, temperatures, operating conditions, quantity ratios and other similar) are modified by "about". Therefore, unless otherwise stated to the contrary, the numerical parameters disclosed in this specification and the accompanying claims are approximate numerical values and may be changed as required. At a minimum, these numerical parameters should be construed to mean the number of significant digits indicated and the numerical values obtained by applying ordinary rounding. Numerical ranges are expressed herein as being from one endpoint to the other or between the endpoints; unless otherwise indicated, the numerical ranges recited herein are inclusive of the endpoints.

FIG. 1 is a functional block diagram of a wireless charging device 100 according to an embodiment of the present application. In this embodiment, the wireless charging device 100 can be coupled to the antenna AT1 and the battery BT1, and can charge the battery BT1 according to the electric field signal ES1 received from the antenna AT1.

The wireless charging device 100 may include a low frequency blocking circuit 110 , a rectifying circuit 120 , a charging path control circuit 130 , a filter capacitor _CF , an overvoltage protection circuit 140 , a battery management circuit 150 , a matched filter circuit 160 and a near field communication controller 170 .

The low frequency blocking circuit 110 can be coupled to the antenna AT1, and can block low frequency noise in the electric field signal ES1. The rectifier circuit 120 can be coupled to the low frequency blocking circuit 110 and can convert the electric field signal ES1 transmitted in the form of alternating current into a direct current signal DS1. The charging path control circuit 130 can be coupled to the rectifier circuit 120 and can turn on or off the charging path of the battery BT1 by the DC signal DS1 according to the charging control signal SIG _CC .

The filter capacitor _CF can be coupled to the charging path control circuit 130, and can smooth the waveform of the DC signal DS1 when the charging path is turned on. The overvoltage protection circuit 140 can be coupled to the filter capacitor _CF. When the voltage of the DC signal DS1 exceeds a critical value, the overvoltage protection circuit 140 can reduce the voltage of the DC signal DS1. The battery management circuit 150 can be coupled to the overvoltage protection circuit 140 and can provide charging power to the battery BT1 according to the DC signal DS1.

The near field communication controller 170 can be coupled to the charging path control circuit 130, and can generate a charging control signal SIG _CC to control the charging path control circuit 130 to turn on or off the charging path of the battery BT1 by the DC signal DS1. For example, when the near field communication controller 170 does not perform near field communication through the antenna AT1, the near field communication controller 170 can make the charging path control circuit 130 conduct the charging path for the battery BT1, and when the near field communication control When the controller 170 needs to send the near field communication signal through the antenna AT1, the near field communication controller 170 can make the charging path control circuit 130 cut off the charging path for the battery BT1.

In addition, the matched filter circuit 160 can be coupled to the antenna AT1 and the near field communication controller 170 . When the near field communication controller 170 wants to send the near field communication signal through the antenna AT1, the matched filter circuit 160 can provide the impedance matching with the antenna AT1 to send the near field communication signal through the antenna AT1. In this embodiment, when the near field communication controller 170 stops generating the near field communication signal, the near field communication controller 170 can not only control the charging path control circuit 130 to turn on the charging path, but also pass the impedance adjustment signal SIG The _IA controls the matched filter circuit 160 to increase the impedance of the matched filter circuit 160 , thereby reducing the electric field signal ES1 of wireless charging to enter the near field communication controller 170 through the matched filter circuit 160 . On the other hand, when the near field communication controller 170 wants to send the near field communication signal through the antenna AT1, the near field communication controller 170 can not only control the charging path control circuit 130 to cut off the charging path, but also pass the impedance adjustment signal SIG _IA to control the matched filter circuit 160 to adjust the impedance of the matched filter circuit 160 so as to transmit the near field communication signal.

Since the near field communication controller 170 can control the charging path control circuit 130 to turn on or off the charging path according to whether the near field communication signal needs to be sent through the antenna AT1, and can also adjust the impedance of the matched filter circuit 160 accordingly, the wireless charging device 100 can separate the paths of near field communication and wireless charging, reducing the mutual restriction between wireless charging efficiency and near field communication quality, so as to improve the efficiency of wireless charging without affecting the quality of near field communication. However, in some other embodiments, under the condition that the matched filter circuit 160 provides a fixed impedance, if the electric field signal ES1 can be effectively reduced from entering the near field communication controller 170, and when the near field communication is performed, the The near field communication signal enters the near field communication controller 170 through the matched filter circuit 160, so that the matched filter circuit 160 can be maintained to provide a fixed impedance, and the near field communication controller 170 may not additionally generate the impedance adjustment signal SIG _IA to control Matched filter circuit 160 .

FIG. 2 is another schematic diagram of the wireless charging device 100 . In FIG. 2, the low frequency blocking circuit 110 may include a first capacitor C1 and a second capacitor C2. The first capacitor C1 has a first end and a second end, and the first end of the first capacitor C1 can be coupled to the first end of the antenna AT1. The second capacitor C2 has a first end and a second end, the first end of the second capacitor C2 can be coupled to the second end of the first capacitor C1, and the second end of the second capacitor C2 can be coupled to the antenna AT1 second end. In this embodiment, the first capacitor C1 can block low-frequency noise in the electric field signal ES1, and the second capacitor C2 and the first capacitor C1 can also divide the voltage of the electric field signal ES1, so that the rectifier circuit 120 can receive the voltage within an appropriate range voltage.

The rectifier circuit 120 includes a first inductor L1 , a second inductor L2 , a first diode D1 , a second diode D2 , a third diode D3 and a fourth diode D4 . The first inductor L1 has a first end and a second end, and the first end of the first inductor L1 can be coupled to the second end of the first capacitor C1. The second inductor L2 has a first terminal and a second terminal, and the first terminal of the second inductor L2 can be coupled to the second terminal of the second capacitor C2.

The first diode D1 has a first end and a second end, the first end of the first diode D1 can be coupled to the second end of the first inductor L1, and the second end of the first diode D1 can be is coupled to the output end of the rectifier circuit 120 . The second diode D2 has a first end and a second end, the first end of the second diode D2 can be coupled to the second end of the second inductor L2, and the second end of the second diode D2 can be is coupled to the output end of the rectifier circuit 120 . The third diode D3 has a first terminal and a second terminal, the first terminal of the third diode D3 can be coupled to the ground terminal GND, and the second terminal of the third diode D3 can be coupled to the first terminal The second end of the inductor L1. The fourth diode D4 has a first terminal and a second terminal, the first terminal of the fourth diode D4 can be coupled to the ground terminal GND, and the second terminal of the fourth diode D4 can be coupled to the second terminal The second end of the inductor L2.

In this embodiment, the first terminals of the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 may be anode terminals, and the first diodes D1, The second terminals of the second diode D2, the third diode D3 and the fourth diode D4 may be cathode terminals. In the rectifier circuit 120, the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 can rectify the electric field signal ES1, and convert the electric field signal originally input in the form of alternating current. ES1 is converted to DC signal DS1.

In addition, since the electric field signal ES1 is an alternating current, if the electric field signal ES1 is attenuated during transmission, it may cause the first diode D1, the second diode D2, the third diode D3 and the fourth diode D1 The conduction angle of the pole tube D4 is small. Furthermore, since the first capacitor C1 and the second capacitor C2 are high-pass filter components, it is difficult to increase the electric field signal ES1 to the first diode D1, the second diode D2, the third diode D3 and the fourth diode. The conduction angle of diode D4. On the other hand, the first inductor L1 and the second inductor L2 can generate self-induced electromotive force, so that the waveform of the electric field signal ES1 changes slowly, thereby increasing the effect of the electric field signal ES1 on the first diode D1 and the second diode. D2, the conduction angles of the third diode D3 and the fourth diode D4, and improve the efficiency of wireless charging.

Since the wireless charging device 100 can separate the paths of near field communication and wireless charging, in the rectifier circuit 120, the first inductance L1 and the second inductance L2 used to increase the conduction angle can improve the efficiency of ineffective charging on the one hand, and on the other hand, in the rectifier circuit 120. On the one hand, it will not affect the matching filter circuit on the near-field communication path to meet the impedance matching conditions, and on the other hand, it will not be unable to improve the conduction angle of the rectifier circuit because of the matching circuit required for near-field communication. Therefore, the wireless charging device 100 of this embodiment can take into account the quality of near field communication and better charging efficiency.

In some embodiments, if the conduction angle of the rectifier circuit 120 can meet the requirements, the first inductor L1 and the second inductor L2 can also be omitted, and the first end of the first diode D1 can be coupled to the The second end of the first capacitor C1, the first end of the second diode D2 can be coupled to the second end of the second capacitor C2, and the second end of the third diode D3 can be coupled to the first capacitor C1 The second end of the fourth diode D4 can be coupled to the second end of the second capacitor C2.

In FIG. 1 , the charging path control circuit 130 may include a first transistor T1 , a second transistor T2 , a control driver 132 and a first resistor R1 . The first transistor T1 has a first terminal, a second terminal and a control terminal, the second terminal of the first transistor T1 can be coupled to the ground terminal GND, and the control terminal of the first transistor T1 can receive the charging control signal SIG _CC . The second transistor T2 has a first terminal, a second terminal and a control terminal. The first terminal of the second transistor T2 can receive the DC signal DS1, and the second terminal of the second transistor T2 can be coupled to the filter capacitor _CF. The first resistor R1 has a first end and a second end, the first end of the first resistor R1 can be coupled to the first end of the second transistor T2, and the second end of the first resistor R1 can be coupled to the second transistor The control terminal of T2.

The control driver 132 can be coupled to the first end of the first transistor T1 and the control end of the second transistor T2, and the control driver 132 can turn on or turn off the second transistor T2 according to the voltage of the first end of the first transistor T1 to enable charging The path is turned on or off. In this embodiment, the control driver 132 may include a third transistor T3, the third transistor T3 has a first end, a second end and a control end, and the first end of the third transistor T3 may be coupled to the control of the second transistor T2 terminal, the second terminal of the third transistor T3 can be coupled to the ground terminal GND, and the control terminal of the third transistor T3 can be coupled to the first terminal of the first transistor T1.

For example, the first transistor T1 and the third transistor T3 may be, for example, but not limited to, N-type transistors, and the second transistor T2 may be, for example, but not limited to, P-type transistors. In this case, when the charging control signal SIG _CC is at a high level, the first transistor T1 will be turned on, and the control terminal voltage of the third transistor T3 will be pulled down to a low level close to the system voltage GND, so that the third transistor T3 is pulled down to a low level close to the system voltage GND. Transistor T3 is turned off. At this time, when the charging path control circuit 130 has received the DC signal DS1, the DC signal DS1 will increase the voltage of the control terminal of the second transistor T2 through the first resistor R1, so that the second transistor T2 is turned off, so that the DC The charging path of the signal DS1 to the battery BT1 is turned off. Conversely, if the charging control signal SIG _CC is at a low level, the first transistor T1 is turned off. In this embodiment, the control terminal of the third transistor T3 can receive a bias voltage related to the electric field signal ES1. Therefore, when the wireless charging device 100 receives the electric field signal ES1 and the first transistor T1 is turned off, the third transistor T1 is turned off. The transistor T3 will be turned on, so that the voltage of the control terminal of the second transistor T2 is pulled down to a low level close to the system voltage GND. At this time, the second transistor T2 will be turned on, so that the DC signal DS1 charges the battery BT1. is turned on.

That is, the near field communication controller 170 can correspondingly turn on or turn off the charging path of the battery BT1 by the DC signal DS1 by adjusting the potential of the charging control signal SIG _CC . In addition, in FIG. 2 , the wireless charging device 100 may further include an electric field detection circuit 180 . The electric field detection circuit 180 can generate the charging detection signal CD1 related to the voltage of the DC signal DS1 according to the DC signal DS1, so that the near field communication controller 170 can further generate the charging control signal SIG _CC according to the charging detection signal CD1.

For example, the near field communication controller 170 can determine the strength of the DC signal DS1 according to the charging detection signal CD1. When the DC signal DS1 is relatively large, it means that there is an external power supply available for wireless charging. At this time, the near field communication controller 170 can keep the charging control signal SIG _CC at a low level without sending the near field communication signal through the antenna AT1. The electric potential turns on the charging path of the battery BT1 by the DC signal DS1 correspondingly. On the other hand, when the DC signal DS1 is too small, it means that there is no external power supply for wireless charging. At this time, the near field communication controller 170 can make the charging control signal SIG _CC at a high level to correspondingly cut off the DC signal DS1 to the battery BT1. charging path.

In this embodiment, the electric field detection circuit 180 may include a filter clamping unit 182 and a voltage dividing unit 184 . The filter clamping unit 182 can filter the DC signal DS1 to generate the electric field reference signal ER1, and the voltage dividing unit 184 can divide the electric field reference signal ER1 to generate the charging detection signal CD1.

The filter clamping unit 182 may include a third resistor R3, a fourth capacitor C4 and a first clamping diode TSV1. The third resistor R3 has a first end and a second end, and the first end of the third resistor R3 can receive the DC signal DS1. The fourth capacitor C4 has a first end and a second end, the first end of the fourth capacitor C4 can be coupled to the second end of the third resistor R3 and can output the electric field reference signal ER1, and the second end of the fourth capacitor C4 It can be coupled to the ground terminal GND. The first clamp diode TSV1 has a first end and a second end, the first end of the first clamp diode TSV1 can be coupled to the first end of the fourth capacitor C4, and the second end of the first clamp diode TSV1 can be is coupled to the second end of the fourth capacitor C4. In this embodiment, the third resistor R3 and the fourth capacitor C4 can filter the DC signal DS1, so that the waveform of the electric field reference signal ER1 is relatively stable. In addition, the first clamping diode TSV1 can provide a voltage relief path to clamp the electric field reference signal ER1 within a safe voltage range when the voltage of the DC signal DS1 is too large. In this case, the first terminal of the first transistor T1 and the control terminal of the third transistor T3 can be coupled to the second terminal of the third resistor R3 to receive the electric field reference signal ER1 as a bias voltage during operation.

The voltage dividing unit 184 includes a fourth resistor R4 and a fifth resistor R5. The fourth resistor has a first end and a second end, and the first end of the fourth resistor R4 can receive the electric field reference signal ER1. The fifth resistor R5 has a first end and a second end, the first end of the fifth resistor R5 can be coupled to the second end of the fourth resistor R4 and can output the charging detection signal CD1, and the second end of the fifth resistor R5 The terminal can be coupled to the ground terminal GND. In this embodiment, the fourth resistor R4 and the fifth resistor R5 can divide the electric field reference signal ER1 to generate the charge detection signal CD1.

In this embodiment, the wireless charging device 100 detects the DC signal DS1 through the electric field detection circuit 180 to generate the charging detection signal CD1, but the present application is not limited to this. In some other embodiments, the wireless charging device 100 can detect the existence of the wireless charging electric field through other types or structures of detection circuits. For example, the wireless charging device 100 can use an electric field detection circuit capable of detecting alternating current to detect the electric field signal ES1 to generate a corresponding charging detection signal, so that the near field communication controller 170 can determine whether the wireless charging electric field exists. And further turn on or off the charging path of the battery BT1. In addition, in some embodiments, if the near field communication controller 170 can determine the timing of wireless charging in other ways, the wireless charging device 100 can also omit the electric field detection circuit 180, as shown in FIG. 1 .

In FIG. 2 , the overvoltage protection circuit 140 may include a first voltage dividing component 142 , a second voltage dividing component 144 , a sixth resistor R6 and a fourth transistor T4 . The first voltage dividing component 142 has a first end and a second end, and the first end of the first voltage dividing component 142 can receive the DC signal DS1. The second voltage dividing element 144 has a first end and a second end. The first end of the second voltage dividing element 144 can be coupled to the second end of the first voltage dividing element 142 , and the second voltage dividing element 144 has a second end. The terminal can be coupled to the ground terminal GND. In this embodiment, the first voltage dividing component 142 and the second voltage dividing component 144 are both implemented by using resistors, and the first voltage dividing component 142 and the second voltage dividing component 144 can divide the DC signal DS1 to generate Overvoltage reference signal OV1.

The sixth resistor R6 has a first end and a second end, and the first end of the sixth resistor R6 can receive the DC signal DS1. The fourth transistor T4 has a first end, a second end and a control end, the first end of the fourth transistor T4 can be coupled to the second end of the sixth resistor R6, and the second end of the fourth transistor T4 can be coupled to ground The terminal GND, and the control terminal of the fourth transistor T4 can be coupled to the second terminal of the first voltage dividing element 142 . The fourth transistor T4 can turn on the voltage relief path formed by the fourth transistor T4 and the sixth resistor R6 according to the overvoltage reference signal OV1 to reduce the voltage value of the DC signal DS1.

In some embodiments, if the overvoltage reference signal OV1 causes the fourth transistor T4 to operate in the saturation region, once the voltage of the DC signal DS1 is too large, the fourth transistor T4 will be completely turned off, and at this time the DC signal DS1 will pass through the pressure relief The path flows into the ground terminal GND, so that the battery management circuit 150 cannot charge the battery BT1 according to the DC signal DS1. However, in this embodiment, the overvoltage reference signal OV1 can be set in an appropriate range through the first voltage dividing component 142 and the second voltage dividing component 144, so that the fourth transistor T4 can mainly operate in the linear region, so the fourth The transistor T4 can control the conduction degree of the pressure relief path according to the magnitude of the overvoltage reference signal OV1. In this way, the DC signal DS1 passing through the overvoltage protection circuit 140 can be maintained within an appropriate voltage range to a limited extent, and the time that the battery management circuit 150 can receive the DC signal DS1 and charge the battery BT1 is prolonged, so that the wireless charging device The charging efficiency of 100 can be further improved.

In this case, in order to provide real-time protection when the DC signal DS1 is over-voltage, the over-voltage protection circuit 140 may further include a second clamping diode TSV2. The second clamping diode TSV2 has a first end and a second end. The first terminals of the two clamping diodes TSV2 can receive the DC signal DS1, and the second terminals of the second clamping diodes TSV2 can be coupled to the ground terminal GND. In this way, when the DC signal DS1 is over-voltage, the second clamping diode TSV2 will be turned on, and can provide a voltage relief path to prevent the battery management circuit 150 from being damaged by receiving high voltage.

In addition, the overvoltage protection circuit 140 may further include a third voltage dividing component 146 and a fourth voltage dividing component 148 . The third voltage divider 146 has a first terminal and a second terminal, the first terminal of the third voltage divider 146 can receive the DC signal DS1, and the second terminal of the third voltage divider 146 can output the overvoltage detection signal OD1 . The fourth voltage dividing element 148 has a first end and a second end, the first end of the fourth voltage dividing element 148 can be coupled to the second end of the third voltage dividing element 146 , and the second end of the fourth voltage dividing element 148 The terminal can be coupled to the ground terminal GND. In this embodiment, the third voltage dividing element 146 is a clamping diode, and the fourth voltage dividing element 148 is a resistor.

The third voltage dividing component 146 and the fourth voltage dividing component 148 can divide the DC signal DS1 to generate the overvoltage detection signal OD1, and the near field communication controller 170 can determine whether the DC signal DS1 is not based on the overvoltage detection signal OD1 Overvoltage can be generated accordingly, and the charging control signal SIG _CC can be generated to turn on or off the charging path of the battery BT1. In addition, the third voltage dividing component 146 and the fourth voltage dividing component 148 can also be used to provide a pressure relief path for the DC signal DS1 to further achieve the function of overvoltage protection, making the operation of the wireless charging device 100 safer.

In FIG. 1 , the wireless charging device 100 may further include a power management circuit 190 , and the power management circuit 190 may be coupled to the battery management circuit 150 . In this case, the battery management circuit 150 can output the power supply to the power management circuit 190 according to the DC signal DS1, and the power management circuit 190 can provide the power required by the near field communication controller 170 according to the supply power. That is, the power obtained through wireless charging can not only be used to charge the battery BT1, but also can be provided to the near field communication controller 170, so that the power obtained through wireless charging can be used more efficiently.

Since the wireless charging device 100 can separate the paths of near field communication and wireless charging, the wireless charging device 100 can set the inductors L1 and L2 in the rectifier circuit 120 to increase the conduction angles of the diodes D1 , D2 , D3 and D4 in the rectifier circuit 120 , thereby improving the efficiency of wireless charging. In addition, the electric field detection circuit 180 can generate a charging detection signal CD1 for the near field communication controller 170 to determine whether there is an electric field signal ES1 capable of providing wireless charging, and turn on or off the charging path control circuit 130 accordingly to enable wireless charging The device 100 can switch between the functions of wireless charging and near field communication more smoothly. Furthermore, since the overvoltage protection circuit 140 can set the overvoltage reference signal OV1 in an appropriate range, so that the fourth transistor T4 can mainly operate in the linear region, the DC signal passing through the overvoltage protection circuit 140 can be limited to a limited extent. The DS1 is maintained within an appropriate voltage range, which prolongs the time during which the battery management circuit 150 can receive the DC signal DS1 and charge the battery BT1 , so that the charging efficiency of the wireless charging device 100 can be further improved.

FIG. 3 is a schematic diagram of a wireless charging device 200 according to another embodiment of the present application. The wireless charging device 200 and the wireless charging device 100 have similar structures and operate according to similar principles. The wireless charging device 200 may include a low frequency blocking circuit 210, a rectification circuit 220, a charging path control circuit 230, a filter capacitor _CF , an overvoltage protection circuit 240, a battery management circuit 250, a matched filter circuit 260, a near field communication controller 270, a filter The clamping unit 282 and the power management circuit 290 .

In FIG. 3 , the low frequency blocking circuit 210 may include a first capacitor C1 , a second capacitor C2 and a third capacitor C3 . The first capacitor C1 and the second capacitor C2. The first capacitor C1 has a first end and a second end, and the first end of the first capacitor C1 can be coupled to the first end of the antenna AT1. The second capacitor C2 has a first terminal and a second terminal, and the first terminal of the second capacitor C2 can be coupled to the second terminal of the first capacitor C1. The third capacitor C3 has a first end and a second end, the first end of the third capacitor C3 can be coupled to the second end of the antenna AT1, and the second end of the third capacitor C3 can be coupled to the second end of the second capacitor C2 second end. In this embodiment, the first capacitor C1 and the third capacitor C3 can block low-frequency noise in the electric field signal ES1, and the second capacitor C2 and the first capacitor C1 and the third capacitor C3 can divide the voltage of the electric field signal ES1, so that The rectifier circuit 220 can receive a voltage within an appropriate range.

In addition, the wireless charging device 200 can generate the bias voltages required by the transistors T1B and T3 in the charging path control circuit 230 through the filter clamping unit 282 . That is to say, in the embodiment of FIG. 3 , the wireless charging device 200 does not provide the charging detection signal CD1 to the near field communication controller 270 through the electric field detection circuit 180 . In this case, the charging detection signal CD1 may be generated by other circuits for the near field communication controller 270 to determine whether the electric field signal ES1 exists, or in some embodiments, the near field communication controller 270 may also rely on other signals or other rules to control the charging path control circuit 230 .

Furthermore, in FIG. 3 , the charging path control circuit 230 may change the MOSFET T1 in the charging path control circuit 130 to a bipolar transistor T1B, and the charging path control circuit 230 may further include a second resistor R2 . The second resistor R2 has a first end and a second end, the first end of the second resistor R2 is coupled to the control end of the first transistor T1B, and the second end of the second resistor R2 is coupled to the second end of the first transistor T1B two ends.

Similarly, in some embodiments, the second transistor T2 and the third transistor T3 can also be implemented as bipolar transistors. However, since the third transistor T3 is disposed on the charging path for the battery BT1, it needs to conduct a larger current. In this case, a MOSFET with a smaller on-resistance is selected to implement the third transistor Transistor T3 will help improve the overall charging efficiency.

Furthermore, in the overvoltage protection circuit 240, the first voltage dividing component 242 is implemented by a clamping diode, and the second voltage dividing component 244 is implemented by using a resistor. The first voltage dividing component 242 and the second voltage dividing component 244 can divide the DC signal DS1 to generate the overvoltage reference signal OV1. That is to say, according to system requirements, the first voltage dividing component 242 can be implemented by a clamping diode or a resistor. Similarly, the third voltage dividing component 246 can also be implemented with a clamping diode or a resistor. For example, in FIG. 3, the third voltage divider component 246 is a clamping diode, and the fourth voltage divider component 218 is a resistor.

To sum up, the wireless charging device provided by the embodiments of the present application can separate the paths of near field communication and wireless charging, so that the efficiency of wireless charging can be improved without affecting the quality of near field communication. For example, the wireless charging device may set an inductor in the rectifier circuit to increase the conduction angle of the rectifier circuit, thereby improving the efficiency of wireless charging. In addition, the wireless charging device can determine whether there is an electric field signal capable of providing wireless charging, and turn on or off the charging path control circuit accordingly, so that the wireless charging device can switch between the functions of wireless charging and near-field communication. smooth. Furthermore, since the overvoltage protection circuit of the wireless charging device can set the overvoltage reference signal in an appropriate range, the time for the battery management circuit to receive the DC signal and charge the battery can be prolonged, so that the charging efficiency of the wireless charging device can be improved. promote.

The foregoing description briefly sets forth features of certain embodiments of the application, so that those skilled in the art to which this application pertains can more fully understand the various aspects of the present disclosure. It should be apparent to those skilled in the art to which this application pertains that they can readily use the present disclosure as a basis to design or modify other processes and structures for carrying out the same purposes and/or of the embodiments described herein achieve the same advantages. Those with ordinary knowledge in the technical field to which this application belongs should understand that these equivalent embodiments still belong to the spirit and scope of the present disclosure, and various changes, substitutions and alterations can be made without departing from the spirit of the present disclosure. with scope.

Claims

A wireless charging device is coupled to an antenna and a battery for charging the battery according to an electric field signal received from the antenna, wherein the wireless charging device comprises:

a low-frequency blocking circuit, coupled to the antenna, for blocking low-frequency noise in the electric field signal;

a rectifier circuit, coupled to the low-frequency blocking circuit, for converting the electric field signal into a DC signal;

a charging path control circuit, coupled to the rectifier circuit, for turning on or off the charging path of the DC signal to the battery according to the charging control signal;

a filter capacitor, coupled to the charging path control circuit, for smoothing the waveform of the DC signal when the charging path is turned on;

an overvoltage protection circuit, coupled to the filter capacitor, for reducing the voltage value of the DC signal when the voltage of the DC signal exceeds a critical value;

a battery management circuit, coupled to the overvoltage protection circuit, for providing charging power to the battery according to the DC signal;

a near field communication controller, coupled to the charging path control circuit, for generating the charging control signal and the near field communication signal; and

A matched filter circuit, coupled to the antenna and the near field communication controller, is used for providing impedance matching with the antenna to transmit the near field communication signal through the antenna.
The wireless charging device of claim 1, wherein the low frequency blocking circuit comprises:

a first capacitor, having a first end and a second end, the first end of the first capacitor is coupled to the first end of the antenna; and

A second capacitor has a first end and a second end, the first end of the second capacitor is coupled to the second end of the first capacitor, and the second end of the second capacitor is coupled to connected to the second end of the antenna;

in:

the first capacitor is used to block the low frequency noise in the electric field signal; and

The second capacitor and the first capacitor are used to divide the voltage of the electric field signal.
The wireless charging device of claim 2, wherein the low frequency blocking circuit further comprises:

A third capacitor has a first end and a second end, the first end of the third capacitor is coupled to the second end of the antenna, and the second end of the third capacitor is coupled to the second end of the second capacitor;

in:

the third capacitor is used to block the low frequency noise in the electric field signal; and

The second capacitor and the third capacitor are used to divide the voltage of the electric field signal.
The wireless charging device according to claim 2 or 3, wherein the rectifying circuit comprises:

A first diode has a first end and a second end, the first end of the first diode is coupled to the second end of the first capacitor, and the first diode the second end of the tube is coupled to the output end of the rectifier circuit;

A second diode has a first end and a second end, the first end of the second diode is coupled to the second end of the second capacitor, and the second diode the second end of the tube is coupled to the output end of the rectifier circuit;

A third diode has a first end and a second end, the first end of the third diode is coupled to the ground end, and the second end of the third diode is coupled to the ground at the second end of the first capacitor; and

a fourth diode, having a first end and a second end, the first end of the fourth diode is coupled to the ground end, and the second end of the fourth diode coupled to the second end of the second capacitor;

The first diode, the second diode, the third diode and the fourth diode are used for rectifying the electric field signal to generate the DC signal.
The wireless charging device of claim 4, wherein the rectifying circuit further comprises:

A first inductor has a first end and a second end, the first end of the first inductor is coupled to the second end of the first capacitor, and the second end of the first inductor a terminal coupled to the first terminal of the first diode; and

A second inductor has a first end and a second end, the first end of the second inductor is coupled to the second end of the second capacitor, and the second end of the second inductor an end coupled to the first end of the second diode;

The first inductance and the second inductance are used to increase the electric field signal to the first diode, the second diode, the third diode and the fourth and second diodes. The conduction angle of the pole tube.
The wireless charging device according to any one of claims 1-5, wherein the charging path control circuit comprises:

The first transistor has a first terminal, a second terminal and a control terminal, the second terminal of the first transistor is coupled to the ground terminal, and the control terminal of the first transistor is used for receiving the charging control signal;

A second transistor has a first end, a second end and a control end, the first end of the second transistor is used for receiving the DC signal, and the second end of the second transistor is coupled to the filter capacitor;

a control driver, coupled to the first end of the first transistor and the control end of the second transistor, the control driver is used for conducting the voltage according to the voltage of the first end of the first transistor turning on or off the second transistor so that the charging path is turned on or off; and

A first resistor has a first end and a second end, the first end of the first resistor is coupled to the first end of the second transistor, and the second end of the first resistor The terminal is coupled to the control terminal of the second transistor.
The wireless charging device of claim 6, wherein the control driver comprises:

A third transistor has a first end, a second end and a control end, the first end of the third transistor is coupled to the control end of the second transistor, the first end of the third transistor is Two terminals are coupled to the ground terminal, and the control terminal of the third transistor is coupled to the first terminal of the first transistor.
The wireless charging device of claim 6, wherein the charging path control circuit further comprises:

A second resistor has a first end and a second end, the first end of the second resistor is coupled to the control end of the first transistor, and the second end of the second resistor is coupled to the second end of the first transistor.
The wireless charging device of claim 6, wherein:

the first transistor is a MOSFET or a bipolar transistor; and

The second transistor is a MOSFET or a bipolar transistor.
The wireless charging device according to any one of claims 6-9, further comprising an electric field detection circuit for generating a charging detection signal according to the DC signal, wherein the voltages of the charging detection signal and the DC signal are Related, and the near field communication controller generates the charging control signal at least according to the charging detection signal.
The wireless charging device of claim 10, wherein the electric field detection circuit comprises:

a filter clamping unit for filtering the DC signal to generate an electric field reference signal; and

The voltage dividing unit is used for generating the charging detection signal by dividing the voltage of the electric field reference signal.
The wireless charging device of claim 11, wherein the filter clamping unit comprises:

a third resistor, having a first end and a second end, and the first end of the third resistor is used for receiving the DC signal;

a fourth capacitor, having a first end and a second end, the first end of the fourth capacitor is coupled to the second end of the third resistor and used for outputting the electric field reference signal, and the the second terminal of the fourth capacitor is coupled to the ground terminal; and

a first clamp diode has a first end and a second end, the first end of the first clamp diode is coupled to the first end of the fourth capacitor, and the first clamp The second end of the diode is coupled to the second end of the fourth capacitor.
The wireless charging device according to claim 11 or 12, wherein the voltage dividing unit comprises:

a fourth resistor, having a first end and a second end, and the first end of the fourth resistor is used for receiving the electric field reference signal;

A fifth resistor has a first end and a second end, the first end of the fifth resistor is coupled to the second end of the fourth resistor and is used for outputting the charging detection signal, and the The second terminal of the fifth resistor is coupled to the ground terminal.
The wireless charging device according to any one of claims 1-13, wherein the overvoltage protection circuit comprises:

a first voltage dividing component, having a first end and a second end, and the first end of the first voltage dividing component is used for receiving the DC signal;

A second voltage dividing element has a first end and a second end, the first end of the second voltage dividing element is coupled to the second end of the first voltage dividing element, and the second the second end of the voltage divider is coupled to the ground;

a sixth resistor, having a first end and a second end, and the first end of the sixth resistor is used for receiving the DC signal;

a fourth transistor, having a first end, a second end and a control end, the first end of the fourth transistor is coupled to the second end of the sixth resistor, the The second terminal is coupled to the ground terminal, and the control terminal of the fourth transistor is coupled to the second terminal of the first voltage dividing element; and

A second clamp diode has a first end and a second end, the first end of the second clamp diode is used for receiving the DC signal, and the second end of the second clamp diode coupled to the ground terminal;

in:

The first voltage dividing component and the second voltage dividing component are used for dividing the voltage of the DC signal to generate an overvoltage reference signal; and

The fourth transistor is used for turning on the voltage relief path jointly formed by the fourth transistor and the sixth resistor according to the overvoltage reference signal to reduce the voltage value of the DC signal.
The wireless charging device of claim 14 , wherein the fourth transistor operates in a linear region to control the degree of conduction of the voltage relief path according to the magnitude of the overvoltage reference signal.
The wireless charging device of claim 14, wherein:

the first voltage dividing component is a resistor or a clamping diode; and

The second voltage dividing component is a resistor.
The wireless charging device of claim 14, wherein the overvoltage protection circuit further comprises:

A third voltage dividing component has a first end and a second end, the first end of the third voltage dividing component is used for receiving the DC signal, and the second end of the third voltage dividing component for outputting an overvoltage detection signal; and

A fourth voltage dividing component has a first end and a second end, the first end of the fourth voltage dividing component is coupled to the second end of the third voltage dividing component, and the fourth the second end of the voltage dividing component is coupled to the ground end;

The near field communication controller generates the charging control signal at least according to the overvoltage detection signal.
The wireless charging device of claim 17, wherein:

the third voltage divider is a resistor or a clamping diode; and

The fourth voltage dividing component is a resistor.
The wireless charging device of claim 1, wherein:

When the near field communication controller stops generating the near field communication signal, the near field communication controller generates the charging control signal to make the charging path control circuit turn on the charging path, and make the charging path The impedance of the matched filter circuit increases; or

When the near field communication controller generates the near field communication signal and transmits the near field communication signal through a matched filter circuit and the antenna, the near field communication controller generates the charging control signal to make the near field communication signal The charging path control circuit cuts off the charging path and reduces the impedance of the matched filter circuit.
The wireless charging device according to any one of claims 1-19, further comprising a power management circuit, coupled to the battery management circuit, wherein:

The battery management circuit is further used for supplying power to the power management circuit according to the DC signal output; and

The power management circuit is used for providing the power required by the near field communication controller according to the supply power.