NFC chip circuit and NFC card thereof
By connecting the voltage divider module in series on the NFC chip and coil, the problem of NFC card burning out during wireless charging of the mobile phone is solved, and effective protection and stable operation of the NFC chip are achieved.
Patent Information
- Application Number
- CN202420855724.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-23
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-04-23
AI Technical Summary
NFC card is prone to burn out when the phone is charged wirelessly, causing trouble for users.
The voltage divider module is connected in series on the NFC chip and the coil. When the coil receives the induced current, the voltage divider module divides the induced current to prevent the NFC chip from being burned out.
Effectively protect the NFC chip, ensure that its induced voltage is within the bearable range, avoid burnout, and tests prove that there are no abnormalities within 48 hours or even longer.
Smart Images
Figure CN222600229U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of NFC technology, and specifically relates to an NFC chip circuit and an NFC card thereof. Background Art
[0002] In the related technologies, with the development of NFC technology, NFC has played an important role in daily life. For example, in the automotive industry, current car manufacturers are gradually introducing smart cards and RFID tags into the automotive industry to replace traditional car keys, and call them NFC car cards (NFC keys or card keys).
[0003] However, in actual usage scenarios, after users open the car door with the NFC car card, they often place the car card in the wireless charging position in the car. When the mobile phone is being wirelessly charged, the NFC car card often burns out, causing great trouble to the user.
[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention
[0005] The purpose of the present application is to provide an NFC chip circuit and an NFC card thereof, which can at least to some extent overcome the technical problems in the related art such as the NFC chip burning out when the NFC card is wirelessly charged in a mobile phone.
[0006] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.
[0007] One aspect of the present application provides an NFC chip circuit, including: an NFC chip and a coil, the NFC chip and the coil are connected in series, and a voltage dividing module is further connected in series between the NFC chip and the coil; the voltage dividing module is used to divide the induced current when the coil receives the induced current, so as to prevent the NFC chip from being burned.
[0008] In one embodiment of the present application, the voltage division module includes a first capacitor.
[0009] In one embodiment of the present application, it also includes:
[0010] An adjustment module, wherein the adjustment module is connected in parallel with the NFC chip and then in series with the voltage divider module, and the adjustment module is also connected in series with the coil, and the adjustment module is used to adjust the resonance of the voltage divider module and the coil.
[0011] In one embodiment of the present application, the voltage division module includes a first capacitor, and the adjustment module includes a second capacitor.
[0012] Another aspect of the present application further provides an NFC card, comprising a card body, wherein the NFC chip circuit as described in any one of the above items is encapsulated in the card body.
[0013] In one embodiment of the present application, the NFC card further includes a first wire,
[0014] The first capacitor is connected to the NFC chip through the first wire;
[0015] The NFC chip is provided with a first wire port and a second wire port, and the first capacitor is provided with a third wire port and a fourth wire port;
[0016] The first wire passes through the first wire port, the third wire port, the fourth wire port and the second wire port in sequence to achieve connection between the first capacitor and the NFC chip;
[0017] A cutting area is formed below the third wire opening and the fourth wire opening, in which the first wire is closed; wherein the cutting area is used for punching by an external cutting device to disconnect the first wire.
[0018] The beneficial effect of the present application is that: in the technical solution provided in the embodiment of the present application, the present application further connects a voltage divider module in series with the NFC chip and the coil. When the coil receives the induced electromotive force of the external device, the voltage divider module is used to reduce the voltage of the external device during wireless charging, which can effectively protect the NFC chip, so as to control the induced voltage obtained by the NFC chip within the range that the chip can withstand.
[0019] In the technical solution provided in the embodiment of the present application, the NFC card provided in the solution of the present application can be used as a smart key card. The smart key card can be placed in the wireless fast charging area of the car. When the wireless fast charger is used to wirelessly charge the mobile phone, the NFC card will not be damaged at all, and there will be no abnormalities after testing for 48 hours or even longer.
[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0022] Figure 1 The circuit block diagram applying the technical solution of the present application is schematically shown.
[0023] Figure 2 The circuit diagram of an embodiment of the present application is schematically shown.
[0024] Figure 3 A circuit block diagram of another embodiment of the present application is schematically shown.
[0025] Figure 4 A circuit diagram of another embodiment of the present application is schematically shown.
[0026] Figure 5 The structural diagram of the NFC card of the present application is schematically shown. DETAILED DESCRIPTION
[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.
[0028] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.
[0029] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.
[0030] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.
[0031] With the continuous development of wireless charging technology, the wireless charging technology of WPC (Wireless Power Consortium) standard came into being. In view of the advantages and development prospects of wireless charging, the electric vehicle wireless charging market will become the fastest growing field in the wireless charging segment.
[0032] Currently, automobile manufacturers are gradually introducing smart cards and RFID tags into the automobile industry to replace traditional car keys, called NFC car cards (NFC keys or card keys). Therefore, automobile manufacturers integrate WPC and NFC readers in the same module. In actual application scenarios, NFC car cards are often placed in the area of the vehicle where the WPC and the wireless charging function are located. This area is also the area where the mobile phone is wirelessly charged. When the mobile phone is wirelessly charged, the NFC car card will burn out.
[0033] Specifically, the chip circuit in the related technology adopts the LC resonance principle, that is, it is composed of a chip, a built-in capacitor in the chip and an inductor coil. The RFID structure used in this method can work normally under ordinary reader-writer conditions. However, there is a possibility of burning out in WPC application scenarios. This is because the wireless charging function in WPC is large. Through the principle of electromagnetic induction, the coil in the NFC car card will obtain strong electromagnetic energy, generating a high induced electromotive force that exceeds the limit value that the chip can withstand, causing burning. For example, when the current mobile phone is charged using the wireless charger in the car, the NFC smart card or RFID tag is in a wireless charging environment. The NFC smart card or RFID tag chip will be broken down and burned out at the moment the mobile phone charging starts or even within tens of seconds.
[0034] In order to solve the above problems, the present application proposes the following technical solutions.
[0035] like Figure 1 As shown, Figure 1 The circuit block diagram applying the technical solution of the present application is schematically shown.
[0036] One aspect of the present application provides an NFC chip circuit, including: an NFC chip U1 and a coil L1, the NFC chip U1 and the coil L1 are connected in series, and a voltage dividing module is also connected in series between the NFC chip U1 and the coil L1; the voltage dividing module is used to divide the induced current when the coil L1 receives the induced current, so as to prevent the NFC chip U1 from being burned.
[0037] In the technical solution provided in the embodiment of the present application, the present application further connects a voltage divider module in series with the NFC chip and the coil. When the coil receives the induced electromotive force of the external device, the voltage divider module is used to reduce the voltage of the external device during wireless charging, which can effectively protect the NFC chip and control the induced voltage obtained by the NFC chip within the range that the chip can withstand.
[0038] In one embodiment of the present application, Figure 2 As shown, Figure 2 The circuit diagram of an embodiment of the present application is schematically shown. The voltage dividing module of the present application includes a first capacitor C1.
[0039] By using the first capacitor 1 as a voltage divider module, the NFC chip can be protected from breakdown. By changing the value of the first capacitor C1, the voltage divider can be controlled, so that different values of the first capacitor C1 can be selected according to different NFC chips to control the induced voltage obtained by the NFC chip within the range that the chip can withstand. Moreover, by changing the value of the first capacitor C1, the capacitance of the first capacitor C1 can be changed, so that the inductive reactance corresponding to the inductance of the coil L and the capacitive reactance corresponding to the capacitance value of the first capacitor C1 can be offset to achieve conjugation. Improve the stability of the entire NFC chip circuit.
[0040] In other embodiments of the present application, the voltage divider module may also use other circuit components, such as resistors, etc. Considering that the NFC card is relatively thin and light, the first capacitor C1 can fit the structure of the NFC card.
[0041] In one embodiment of the present application, the capacitance of the first capacitor may be 220 pF.
[0042] In one embodiment of the present application, Figure 3 As shown, Figure 3 A circuit block diagram of another embodiment of the present application is schematically shown.
[0043] The NFC chip circuit of the present application further includes an adjustment module, which is connected in parallel with the NFC chip U1 and then in series with the voltage divider module. The adjustment module is also connected in series with the coil L1, and the adjustment module is used to adjust the resonance of the voltage divider module and the coil L1.
[0044] The resonance between the voltage divider module and the coil L1 can be effectively adjusted through the adjustment module. Therefore, it can be applicable to most NFC chips. For example, when the limit voltage of some NFC chips is very small and it is difficult to adjust it with the voltage divider module alone, the adjustment module can be used to adapt to different NFC chips and adjust the resonance between the voltage divider module and the coil L1 to improve stability.
[0045] In one embodiment of the present application, Figure 4 As shown, Figure 4 A circuit diagram of another embodiment of the present application is schematically shown. In this embodiment, the voltage dividing module includes a first capacitor C1, and the adjustment module includes a second capacitor C2.
[0046] In one embodiment of the present application, the capacitance of the first capacitor C1 may be 680 pF, and the capacitance of the second capacitor C2 may be 68 pF.
[0047] By connecting the first capacitor 1 in series, the voltage division protection chip can be achieved, and by connecting the second capacitor in parallel, the LC resonance of the chip can be better adjusted. Moreover, by changing the value of the first capacitor C1 and the second capacitor C2, the capacitance of the first capacitor C1 and the second capacitor C2 can be changed, so that the inductance of the coil L and the inductive reactance and capacitive reactance corresponding to the capacitance of the first capacitor C1 and the second capacitor C2 can be offset to achieve conjugation, thereby improving the stability of the entire NFC chip circuit.
[0048] like Figure 5 As shown, Figure 5 The structural diagram of the NFC card of the present application is schematically shown. Another aspect of the present application further provides an NFC card, comprising a card body 1, wherein the card body 1 encapsulates an NFC chip circuit as described above.
[0049] In one embodiment of the present application, reference Figure 5 The card body 1 is encapsulated with an NFC chip 3 and a first capacitor 2 .
[0050] The NFC card provided by the present application can be used as a smart key card. The smart key card is placed in the wireless fast charging area of the car. When the wireless fast charger is used to wirelessly charge the mobile phone, when the coil receives the induced electromotive force of the external device, the voltage divider module is used to reduce the voltage of the external device during wireless charging, which can effectively protect the NFC chip and control the induced voltage obtained by the NFC chip within the range that the chip can withstand. Therefore, the NFC card of the present application has no damage and is still normal after testing for 48 hours or even longer.
[0051] In one embodiment of the present application, the NFC card further includes a first wire, and the first capacitor is connected to the NFC chip through the first wire; the NFC chip is provided with a first wire port and a second wire port, and the first capacitor is provided with a third wire port and a fourth wire port;
[0052] The first wire passes through the first wire port, the third wire port, the fourth wire port and the second wire port in sequence to connect the first capacitor to the NFC chip;
[0053] A cutting area is formed below the third wire opening and the fourth wire opening, in which the first wire is closed; wherein the cutting area is used for punching by an external cutting device to disconnect the first wire.
[0054] In this embodiment, the NFC card of the present application uses the first wire to pass through the first wire port, the third wire port, the fourth wire port and the second wire port in sequence to achieve the connection between the first capacitor and the NFC chip. Therefore, only one wire can be used to achieve the connection, which reduces the complexity of the process and the thickness. It can be effectively used in the NFC card to reduce the thickness of the NFC card.
[0055] Moreover, the present application forms a cutting area below the third wire port and the fourth wire port, and uses an external cutting device to punch the cutting area, thereby avoiding a short circuit between the first capacitor and the NFC chip, improving safety, and making the manufacturing process simpler.
[0056] It should be noted that although the steps of the method in the present application are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.
[0057] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.
[0058] It should be noted that, although several modules or units of the equipment for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into being embodied by multiple modules or units.
[0059] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.
[0060] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.
Claims
1. An NFC chip circuit, characterized in that: include: An NFC chip and a coil, wherein the NFC chip and the coil are connected in series, and a voltage dividing module is also connected in series between the NFC chip and the coil; the voltage dividing module is used to divide the induced current when the coil receives the induced current, so as to prevent the NFC chip from being burned.
2. The NFC chip circuit according to claim 1, characterized in that: The voltage dividing module includes a first capacitor.
3. The NFC chip circuit according to claim 1, characterized in that: Also includes: An adjustment module, wherein the adjustment module is connected in parallel with the NFC chip and then in series with the voltage divider module, and the adjustment module is also connected in series with the coil, and the adjustment module is used to adjust the resonance of the voltage divider module and the coil.
4. The NFC chip circuit according to claim 3, characterized in that: The voltage dividing module includes a first capacitor, and the adjusting module includes a second capacitor.
5. An NFC card, characterized in that: The invention comprises a card body, wherein the NFC chip circuit as claimed in any one of claims 1 to 4 is encapsulated in the card body.
6. The NFC card according to claim 5, characterized in that: Also includes a first conductor, The first capacitor is connected to the NFC chip through the first wire; The NFC chip is provided with a first wire port and a second wire port, and the first capacitor is provided with a third wire port and a fourth wire port; The first wire passes through the first wire port, the third wire port, the fourth wire port and the second wire port in sequence to achieve connection between the first capacitor and the NFC chip; A cutting area is formed below the third wire opening and the fourth wire opening, in which the first wire is closed; wherein the cutting area is used for punching by an external cutting device to disconnect the first wire.