CN215420286U

CN215420286U - NFC communication circuit, shell assembly and NFC communication system

Info

Publication number: CN215420286U
Application number: CN202121750930.0U
Authority: CN
Inventors: 吴立强
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2022-01-04
Anticipated expiration: 2031-07-29

Abstract

The application relates to an NFC communication circuit, casing subassembly and NFC communication system, wherein, NFC communication circuit includes: a first NFC antenna for coupling with an external NFC device; the first switch module is connected with the first NFC antenna; the resonance module is connected with the first switch module; and the control module is respectively connected with the resonance module and the first switch module and used for controlling the switch state of the first switch module according to the output voltage of the resonance module so as to switch on or off the connection between the resonance module and the first NFC antenna. Whether the communication object of the electronic equipment is the circuit or not can be identified according to the output voltage of the resonance module, and the on-off state of the first switch module is controlled accordingly, so that the resonance frequency of the first NFC antenna is changed. Therefore, the influence of the first NFC antenna on the load of the NFC module of the electronic equipment can be avoided, and the resonance frequency of the electronic equipment is kept as the target resonance frequency, so that the NFC performance of the electronic equipment is prevented from being reduced.

Description

NFC communication circuit, shell assembly and NFC communication system

Technical Field

The present application relates to the field of communications technologies, and in particular, to an NFC communication circuit, a housing assembly, and an NFC communication system.

Background

With the richness of the integrated functions of electronic devices, NFC (Near Field Communication) is widely used in various aspects. Currently, NFC functionality of electronic devices includes card emulation, reader/writer, and P2P (Peer-to-Peer) transmission. In order to further broaden the functions of the electronic device, a housing assembly (e.g., a terminal protection housing) used in cooperation with the electronic device has been developed, where the housing assembly is provided with a first NFC antenna and a corresponding application circuit, and the first NFC antenna of the housing assembly may be coupled with an NFC module of the electronic device to drive the application circuit and implement a corresponding function.

However, when the housing assembly is used in cooperation with the electronic device, the NFC performance of the electronic device may be degraded, which may affect the original NFC function of the electronic device.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an NFC communication circuit, a shell assembly and an NFC communication system, and the NFC performance of electronic equipment can be prevented from being influenced when the NFC communication circuit is matched with the electronic equipment for use.

An NFC communications circuit, comprising:

a first NFC antenna for coupling with an external NFC device;

the first switch module is connected with the first NFC antenna;

the resonance module is connected with the first switch module;

and the control module is respectively connected with the resonance module and the first switch module and used for controlling the switch state of the first switch module according to the output voltage of the resonance module so as to switch on or off the connection between the resonance module and the first NFC antenna.

A housing assembly comprising:

the NFC communication circuit described above;

the NFC communication circuit is arranged on the shell.

An NFC communication system comprising:

the above-mentioned housing assembly;

an electronic device including a second NFC antenna coupled with the first NFC antenna.

According to the NFC communication circuit, the shell assembly and the NFC communication system, the resonance module is connected with the first NFC antenna through the first switch module, the control module is respectively connected with the resonance module and the first switch module, and the on-off state of the first switch module is controlled according to the output voltage of the resonance module. The output voltage of the resonance module reflects the field intensity of the first NFC antenna coupled to the resonance module, and whether the first NFC antenna is coupled with the NFC module of the electronic device or coupled with other NFC devices can be identified through the field intensity. Meanwhile, the function mode of the electronic equipment can be judged according to the field intensity, namely the electronic equipment carries out card simulation, reader-writer or P2P transmission. Therefore, the control module can identify whether a communication object of the electronic device is the circuit according to the output voltage of the resonance module, and control the on-off state of the first switch module according to the identification result so as to change the resonance frequency of the first NFC antenna, so that the resonance frequency of the first NFC antenna is the target resonance frequency of NFC communication or deviates from the target resonance frequency. When the resonant frequency of the first NFC antenna is the target resonant frequency, the first NFC antenna may perform NFC communication with the electronic device. When the resonant point of the first NFC antenna deviates from the target resonant frequency, the first NFC antenna can be prevented from affecting the load of the NFC module of the electronic device, and it is further ensured that the resonant frequency of the electronic device is kept at the target resonant frequency, so as to prevent the NFC performance of the electronic device from being degraded. The electronic device can communicate with the remaining NFC communication circuits/devices other than the NFC communication circuit of the housing assembly to implement functions such as card emulation, card reader, and P2P transport.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an NFC communication circuit according to an embodiment;

fig. 2 is a second schematic structural diagram of an NFC communication circuit according to an embodiment;

fig. 3 is a third schematic structural diagram of an NFC communication circuit according to an embodiment;

fig. 4 is a fourth schematic structural diagram of an NFC circuit according to an embodiment;

fig. 5 is a fifth schematic structural diagram of an NFC communication circuit according to an embodiment;

fig. 6 is a sixth schematic structural diagram of an NFC circuit according to an embodiment;

fig. 7 is a seventh schematic structural diagram of an NFC communication circuit according to an embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first capacitance may be referred to as a second capacitance, and similarly, a second capacitance may be referred to as a first capacitance, without departing from the scope of the present application. The first and second capacitances are both capacitances, but they are not the same capacitance.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments is understood to mean "electrical connection", "communication connection", or the like, if there is a transfer of electrical signals or data between the connected objects.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, as used in this specification, the term "and/or" includes any and all combinations of the associated listed items.

As mentioned in the background, when the housing assembly is used with an electronic device, the NFC performance of the electronic device may be degraded, which may affect the original NFC function of the electronic device. The inventor finds that the reason for the problem is that the NFC antenna of the housing component is close to the NFC module of the electronic device and has a close resonant frequency, so that the NFC antenna of the housing component affects the load of the NFC module of the electronic device, and the resonant frequency of the NFC module of the electronic device changes. The change of the resonant frequency greatly affects the transceiving performance of the NFC module of the electronic device, so that the NFC performance of the electronic device is reduced, and even the NFC performance is disabled. When casing subassembly and electronic equipment cooperation were used, electronic equipment's NFC module only can be used to drive the casing subassembly, and can't communicate with the NFC communication circuit except that casing subassembly, lead to unable functions such as realizing card simulation, read write line and P2P transmission, influence user experience greatly.

Based on this, the embodiment of the application provides an NFC communication circuit, a housing assembly and an NFC communication system, which can avoid influencing the NFC performance of an electronic device when being used in cooperation with the electronic device.

The embodiment of the application provides an NFC communication circuit, which can be coupled with an electronic device to obtain energy from the electronic device and drive the circuit to work. It is understood that the electronic device may be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable wearable devices. It should be understood that the NFC communication circuit may also interact with NFC devices other than electronic devices to achieve corresponding functionality.

As shown in fig. 1, the NFC communication circuit includes a first NFC antenna 110, a first switching module 120, a resonance module 130, and a control module 140, which are connected in sequence, and the control module 140 is further connected to the first switching module 120.

The first NFC antenna 110 refers to an antenna structure capable of radiating NFC radio frequency signals, that is, an antenna capable of coupling with an external NFC device to obtain energy. Specifically, when the NFC communication circuit is used with an electronic device, the first NFC antenna may be coupled to a second NFC antenna on the electronic device to harvest energy and drive the circuit to operate.

It is understood that the first NFC antenna 110 may be an NFC antenna of any structure, and the present application is not limited thereto. In one example, the first NFC antenna 110 may be a coil structured antenna.

The resonance module 130 refers to a circuit capable of adjusting a resonance frequency of the first NFC antenna 110. Considering that NFC communication needs to be performed at a target resonant frequency (e.g., 13.56MHz), the resonant frequency of the first NFC antenna 110 needs to be adjusted to the target resonant frequency to improve the coupling efficiency of the first NFC antenna 110 with an external NFC device, so that the NFC communication is performed normally. The first NFC antenna 110 may implement the adjustment of the resonant frequency by connecting the resonance module 130. It is understood that the specific circuit structure and component parameters of the resonance module 130 can be determined according to the antenna parameter and the target resonance frequency of the first NFC antenna 110, which is not particularly limited in this application.

The control module 140 refers to a circuit or a device having a signal acquisition function, a data processing function, and a signal output function, and may be implemented by a circuit having a certain structure or a control device. In one example, the control module 140 may include an IC (Integrated Circuit) chip.

Specifically, when the first switch module 120 is turned on, the resonance module 130 is connected to the first NFC antenna 110, and the resonance frequency of the first NFC antenna 110 is adjusted to a target resonance frequency, so as to couple with an external NFC device with high coupling efficiency and obtain energy. The output voltage of the resonance module 130 is associated with the coupling energy of the first NFC antenna 110, the coupling energy of the first NFC antenna 110 is associated with the magnitude of the field intensity coupled thereto, and the magnitude of the field intensity is associated with the distance between the first NFC antenna 110 and the external NFC device. When the distance between the first NFC antenna 110 and the external NFC device is small, the field strength is large, the first NFC antenna 110 can couple to more energy, and the output voltage of the resonance module 130 is large; when the distance between the first NFC antenna 110 and the external NFC device is larger, the field strength is smaller, the energy coupled to the first NFC antenna 110 is smaller, and the output voltage of the resonant module 130 is also smaller. Further, the magnitude of the field strength is also associated with the radiated energy of the external NFC device, which can be differentiated when implementing different NFC functions. When the radiation energy of the external NFC device is larger, the field strength is larger, the first NFC antenna 110 can be coupled to more energy, and the output voltage of the resonance module 130 is larger; when the radiation energy of the external NFC device is smaller, the field strength is smaller, the coupling energy of the first NFC antenna 110 is smaller, and the output voltage of the resonant module 130 is also smaller.

The control module 140 may determine a distance between the first NFC antenna 110 and an external NFC device through the output voltage of the resonance module 130, and further determine whether the first NFC antenna 110 is coupled with an electronic device or coupled with another NFC device (such as an entrance guard or an attendance machine) other than the electronic device. Meanwhile, the control module 140 may determine the functional mode of the electronic device through the output voltage of the resonance module 130, that is, whether the electronic device is driving the circuit or attempting to communicate with other NFC devices except for the circuit. In this way, the control module 140 can identify whether the communication object of the electronic device is the circuit according to the output voltage of the resonance module 130. The control module 140 controls a switching state of the first switching module 120 according to the identification result to turn on or off the connection between the resonance module 130 and the first NFC antenna 110. When the resonance module 130 is connected to the first NFC antenna 110 through the first switch module 120, the resonance frequency of the first NFC antenna 110 is a target resonance frequency of NFC communication, so that the first NFC antenna 110 can perform NFC communication with an electronic device. Under the condition that the first switch module 120 is turned off, the resonance module 130 is disconnected from the first NFC antenna 110, and the resonant frequency of the first NFC antenna 110 deviates from the target resonant frequency, so that the first NFC antenna 110 can be prevented from affecting the load of the NFC module of the electronic device, the resonant frequency of the electronic device can be kept at the target resonant frequency of NFC communication, and the NFC performance of the electronic device can be prevented from being reduced. Meanwhile, the electronic device can also communicate with other NFC communication circuits/devices except the NFC communication circuit described in the embodiment, so as to implement functions of card emulation, card reader, P2P transmission, and the like.

As shown IN FIG. 2, IN one embodiment, the resonant module 130 includes a first output terminal OUT1, a second output terminal OUT2, a first input terminal IN1, and a second input terminal IN 2. Here, the output voltage of the resonant module 130 may be understood as a voltage of the first output terminal OUT1, a voltage of the second output terminal OUT2, and/or a voltage difference between the first output terminal OUT1 and the second output terminal OUT2, and the input voltage of the resonant module 130 may be understood as a voltage of the first input terminal IN1, a voltage of the second input terminal IN2, and/or a voltage difference between the first input terminal IN1 and the second input terminal IN 2. The first switch module 120 includes a first terminal, a second terminal, and a control terminal. The first switch module 120 may switch on or off the connection between the first terminal and the second terminal according to the voltage/current of the control terminal, so as to switch on and off the first switch module 120.

The control module 140 is respectively connected to the first output terminal OUT1, the second output terminal OUT2, the first terminal of the first switch module 120 and the control terminal of the first switch module 120, and is configured to control the switching state of the first switch module 120 according to a voltage difference between the output voltage of the first output terminal OUT1 and the output voltage of the second output terminal OUT2 (i.e., a first voltage difference) and a voltage difference between the output voltage of the first output terminal OUT1 and the voltage of the first terminal of the first switch module 120 (i.e., a second voltage difference). The first voltage difference reflects the magnitude of the coupling field strength of the first NFC antenna 110 when the first switching module 120 is turned on, and the second voltage difference reflects the magnitude of the coupling field strength of the first NFC antenna 110 when the first switching module 120 is turned off.

The first terminal of the first switch module 120 is connected to the first NFC antenna 110, the second terminal of the first switch module 120 is connected to the first input terminal IN1 of the resonant module 130, and the second input terminal IN2 of the resonant module 130 is connected to the first NFC antenna 110. When the first switch module 120 is turned on, a loop is formed between the first NFC antenna 110 and the resonance module 130, and under the action of the resonance module 130, the resonance frequency of the first NFC antenna 110 is adjusted to the target resonance frequency, so as to perform NFC communication with the electronic device. When the first switch module 120 is turned off, a loop cannot be formed between the first NFC antenna 110 and the resonance module 130, the NFC communication circuit is in a circuit-open state, and the resonant frequency of the first NFC antenna 110 deviates from the target resonant frequency, so that the NFC module of the electronic device is prevented from being affected, the electronic device can communicate with other NFC devices, and the original NFC function is realized.

In this embodiment, the control module 140 is respectively connected to the first output end OUT1 and the second output end OUT2 of the resonance module 130, the first end of the first switch module 120, and the control end of the first switch module 120, and the coupling field strength of the first NFC antenna 110 can be detected in different switching states of the first switch module 120, so as to adjust the switching state of the first switch module 120 accordingly. Therefore, the influence of the first NFC antenna 110 on the NFC function of the electronic device can be further reduced, and the NFC performance of the electronic device in cooperative use can be improved.

As shown in fig. 3, in one embodiment, the resonant module 130 includes a first capacitor C1 and a second capacitor C2. First ends of the first capacitors C1 are respectively connected to first ends of the first NFC antenna 110 and the second capacitors C2, and second ends of the first capacitors C1 are respectively connected to first terminals of the first switch module 120A second terminal and a second terminal of a second capacitor C2. The first terminal of the second capacitor C2 and the second terminal of the second capacitor C2 are respectively connected to the control module 140. A first end of the first capacitor C1 is used as the second input end IN2 of the resonant module 130, a second end of the first capacitor C1 is used as the first input end IN1 of the resonant module 130, a first end of the second capacitor C2 is used as the second output end OUT2 of the resonant module 130, a second end of the second capacitor C2 is used as the first output end OUT1 of the resonant module 130, the first voltage difference is V_ABThe second pressure difference is V_BC. It is to be understood that the specific capacitance values of the first capacitor C1 and the second capacitor C2 can be determined according to the antenna parameters of the first NFC antenna 110 and the target resonant frequency, which is not limited in this application. The resonance module 130 is realized by the two capacitors in the embodiment, so that the volume of the NFC communication circuit can be reduced, and the NFC communication circuit can be conveniently arranged and integrated.

In one embodiment, the first switch module 120 includes one or more electronic switch tubes, wherein the electronic switch tubes may be, but are not limited to, MOS tubes and transistors. It is understood that the specific connection relationship of the electronic switch tube may be determined according to the control signal type (such as current signal or voltage signal) of the electronic switch tube, the conduction condition of the electronic switch tube, and the like, which is not limited in this application. IN one example, as shown IN fig. 3, the first switching module 120 may be implemented by a PNP transistor, a base of the PNP transistor is connected to the control module 140, an emitter of the PNP transistor is connected to the first NFC antenna 110, and a collector of the PNP transistor is connected to the first input terminal IN1 of the resonant module 130. In this embodiment, the first switch module 120 is implemented by an electronic switch tube, so that the integration level of the NFC communication circuit can be improved, and the circuit volume can be reduced.

In one embodiment, the control module 140 is configured to, when the first switching module 120 is turned on, control the first switching module 120 to turn on the connection between the resonance module and the first NFC antenna if the first voltage difference is greater than a first threshold or the first voltage difference is equal to zero; if the first voltage difference is not zero and is smaller than the first threshold, the first switch module 120 is controlled to disconnect the resonance module from the first NFC antenna.

The control module 140 is further configured to, when the first switch module 120 is turned off, control the first switch module 120 to turn on the connection between the resonance module and the first NFC antenna if the second voltage difference is zero; if the second voltage difference is not zero, the first switching module 120 is controlled to disconnect the resonance module from the first NFC antenna.

Specifically, the first NFC antenna 110 may be in one of three coupling states: state one, the first NFC antenna 110 is not coupled with an external NFC device; in the second state, the first NFC antenna 110 is coupled to an external NFC device, and the coupling field strength is large, so that the first voltage difference is greater than the first threshold; in state three, the first NFC antenna 110 is coupled to an external NFC device and the coupling field strength is small, such that the first voltage difference is smaller than the first threshold or the second voltage difference is larger than zero. When the NFC communication circuit is coupled to the electronic device, since the distance between the electronic device and the NFC communication circuit is small, the resonance module 130 outputs a high voltage after the first NFC antenna 110 is coupled to the radio frequency field emitted by the electronic device. When the NFC communication circuit and the electronic device are close to other external NFC devices (such as a door access device and an attendance machine), the distance (for example, a distance greater than 2 centimeters) between the NFC communication circuit and the other external NFC devices can be controlled, so that the resonant module 130 outputs a lower voltage after the first NFC antenna 110 is coupled with the radio frequency field emitted by the other external NFC devices. It can be understood that the specific value of the first threshold may be configured according to actual requirements, and this application does not specifically limit this, as long as it can distinguish the electronic device from other external NFC devices.

The control module 140 is configured to determine a coupling state of the first NFC antenna 110 according to the first voltage difference. If the first NFC antenna 110 is in the first state or the second state, the first switch module 120 is turned on; if the first NFC antenna 110 is in state three, the first switching module 120 is turned off. When the current state of the first NFC antenna 110 is state one, the first switching module 120 is in a conducting state. When the last state of the first NFC antenna 110 is the first state and the current state is the second state, the first switching module 120 remains in the conducting state. When the current state of the first NFC antenna 110 is state one and the current state is state three, the first switch module 120 is switched to the off state. When the last state of the first NFC antenna 110 is state two and the current state is state one, the first switching module 120 remains in the on state. When the last state of the first NFC antenna 110 is state three and the current state is state one, that is, the first switch module 120 is turned off and the second voltage difference is zero, the first switch module 120 may be restored to the on state.

It is understood that, in this embodiment, the control module may implement the foregoing functions by a hardware circuit, for example, the control module may include a voltage comparison circuit, an add-subtract circuit, or the like.

In one example, for the NFC communication circuit shown in fig. 3, the switching logic table of the first switch module 120 may be as shown in table 1, wherein the second voltage difference is zero when the first switch module 120 is turned on, because the turning on of the first switch module 120 may cause the first output terminal OUT1 and the first terminal of the first switch module 120 to be short-circuited.

TABLE 1 switching logic table of a first switch module

Fig. 4 is a schematic diagram illustrating the switching of the switch state of the first switch module 120 in the circuit configuration shown in fig. 3. As shown in fig. 4, V is the first NFC antenna 110 is outside the coupling range of the external NFC device_AB＝0,V_BCThe first switching module 120 is turned on, which is equal to 0. If the first NFC antenna 110 comes within the coupling range of the external NFC device, V_AB≠0,V_BC0, the control module 140 is based on V_ABControls the switching state of the first switching module 120. If V_ABIf the value is greater than the first threshold, the first NFC antenna 110 is in the second coupling state, and the first switching module 120 remains on. If the first NFC antenna 110 leaves the coupling range of the external NFC device, V_ABThe first NFC antenna 110 is in the first coupling state, and the first switching module 120 remains on.

If V_ABIf the value is smaller than the first threshold, the first NFC antenna 110 is in the third coupling state, the first switch module 120 is adjusted from the on state to the off state, and V is set to V after the first switch module is turned off_AB0 and V_BC≠0. When the first NFC antenna 110 leaves the coupling range of an external NFC device, V_BCIf the coupling state of the first NFC antenna 110 is equal to 0, the first switching module 120 is switched to the on state.

In this embodiment, it is determined whether the radio frequency field coupled to the first NFC antenna 110 is emitted by the electronic device or emitted by another NFC device through the output voltage of the resonance module 130, and the on-off state of the first switch module 120 is controlled accordingly, so that the card simulation function of the electronic device can be prevented from being affected when the function of the NFC communication circuit is implemented.

In one embodiment, the control module 140 is configured to, when the first switching module 120 is turned on, control the first switching module 120 to turn on the connection between the resonance module and the first NFC antenna if the first voltage difference is smaller than the second threshold; if the first voltage difference is greater than the second threshold, the first switch module 120 is controlled to disconnect the resonance module from the first NFC antenna.

The first NFC antenna 110 may be in one of three coupling states: state one, the first NFC antenna 110 is not coupled with an external NFC device; in the second state, the first NFC antenna 110 is coupled with an external NFC device, and the coupling field strength is small, so that the first voltage difference is not zero and is smaller than the second threshold; in state three, the first NFC antenna 110 is coupled to an external NFC device and the coupling field strength is large, such that the first voltage difference is larger than the second threshold. It is understood that the specific value of the second threshold can be configured according to the actual requirement, and the application is not limited thereto.

When the NFC communication circuit is used in cooperation with an electronic device, if the electronic device is in a reader/writer mode or a P2P transmission mode, the radio frequency field intensity emitted by the electronic device is larger, and after the first NFC antenna 110 is coupled with the electronic device, the resonance module 130 outputs a higher voltage.

Similar to the previous embodiment, in the present embodiment, the control module 140 is configured to determine the coupling state of the first NFC antenna 110 according to the first voltage difference. If the first NFC antenna 110 is in the first state or the second state, the first switch module 120 is turned on; if the first NFC antenna 110 is in state three, the first switching module 120 is turned off. When the current state of the first NFC antenna 110 is state one, the first switching module 120 is in a conducting state. When the last state of the first NFC antenna 110 is the first state and the current state is the second state, the first switching module 120 remains in the conducting state. When the current state of the first NFC antenna 110 is state one and the current state is state three, the first switch module 120 is switched to the off state. When the last state of the first NFC antenna 110 is state two and the current state is state one, the first switching module 120 remains in the on state. When the last state of the first NFC antenna 110 is state three and the current state is state one, that is, the first switch module 120 is turned off and the second voltage difference is zero, the first switch module 120 may be restored to the on state.

In this embodiment, the output voltage of the resonance module 130 is used to determine the functional mode of the electronic device, that is, the electronic device is performing card simulation, reader/writer or P2P transmission, so as to identify whether the communication object of the electronic device is the circuit, and accordingly control the on/off state of the first switch module 120, thereby avoiding affecting the functions of the reader/writer and P2P transmission of the electronic device when the function of the NFC communication circuit is implemented.

As shown in fig. 5, in one embodiment, the NFC communication circuit further includes a second switch module 150 and an application circuit 160, where the number of the application circuit 160 may be one or more, and the specific number thereof may be determined according to actual requirements, which is not particularly limited in this application. It is understood that the functions implemented by the application circuit 160 can also be determined according to actual requirements, and the application is not limited thereto. In one example, the application circuit 160 may be at least one of a light emitting circuit, a distance detection circuit, and a temperature detection circuit.

The second switch module 150 is respectively connected to the first output terminal OUT1, the control module 140 and the application circuit 160, and the application circuit 160 is connected to the second output terminal OUT 2. The control module 140 is configured to control a switching state of the second switching module 150 according to the first voltage difference to connect or disconnect the application circuit 160 and the resonance module 130. Under the condition that the first switch module 120 and the second switch module 150 are both turned on, the first NFC antenna 110, the resonance module 130, and the application circuit 160 form a loop, so that the application circuit 160 can operate under the driving of the output voltage of the resonance module 130 and realize corresponding functions. In case the second switching module 150 is opened, the connection between the application circuit 160 and the resonance module 130 is also opened, so that the application circuit 160 stops operating.

It is understood that, in this embodiment, the control module may implement the foregoing functions by a hardware circuit, for example, the control module may be a voltage comparison circuit or an add-subtract circuit.

In this embodiment, the control module 140 controls the switching state of the second switching module 150 through the first voltage difference to turn on or off the connection between the application circuit 160 and the resonance module 130, so that the controllability of the application circuit 160 can be improved, and the application scenarios of the NFC communication circuit can be widened.

As shown in fig. 6, in one embodiment, the number of the application circuits 160 is multiple, the number of the second switch modules 150 is multiple, the multiple second switch modules 150 are connected to the multiple application circuits 160 in a one-to-one correspondence, and each second switch module 150 is connected to the first output terminal OUT1 and the control module 140. It should be noted that any two application circuits 160 may be application circuits (for example, both of the application circuits are light emitting circuits) that realize the same function, or may also be application circuits that realize different functions, and the application is not particularly limited thereto.

The control module 140 may control the on/off state of each second switch module 150 according to the second voltage difference to select different application circuits 160 to operate, such as controlling a plurality of LED lamps respectively, so as to implement corresponding functions. In the embodiment, the plurality of second switch modules 150 are connected to the plurality of application circuits 160 in a one-to-one correspondence manner, so that the operating state of each application circuit 160 can be controlled respectively, thereby improving the flexibility of the NFC communication circuit.

In one embodiment, the second switch module 150 includes one or more electronic switch transistors, which may be, but not limited to, MOS transistors and transistors. It is understood that the specific connection relationship of the electronic switch tube may be determined according to the control signal type (such as current signal or voltage signal) of the electronic switch tube, the conduction condition of the electronic switch tube, and the like, which is not limited in this application. In one example, as shown in fig. 6, the second switching module 150 may be implemented by a PNP transistor having a base connected to the control module 140, an emitter connected to the application circuit 160, and a collector connected to the first output terminal OUT1 of the resonance module 130. In this embodiment, the second switch module 150 is implemented by an electronic switch tube, so that the integration level of the NFC communication circuit can be improved, and the circuit volume can be reduced.

Fig. 7 shows a circuit configuration of an NFC communication circuit in one example. The NFC communication circuit includes a first NFC antenna 110, a first switching module 120, a first capacitor C1, a second capacitor C2, a control module 140, a plurality of application circuits 160, and a plurality of second switching modules 150. The first NFC antenna 110 is an antenna with a coil structure, the first switch module 120 is a PNP transistor, the second switch module 150 is a PNP transistor, and the control module 140 is implemented by an IC. Specifically, a first end of the first NFC antenna 110 is connected to a first end of a first capacitor C1, a first end of the first capacitor C1 is connected to a first end of a second capacitor C2, a first end of the second capacitor C2 is connected to a plurality of application circuits 160, the plurality of application circuits 160 are connected to first ends of a plurality of second switch modules 150 in a one-to-one correspondence manner, second ends of the plurality of second switch modules 150 are all connected to a second end of a second capacitor C2, a second end of the second capacitor C2 is connected to a second end of a first capacitor C1, a second end of the first capacitor C1 is connected to a second end of the first switch module 120, and the first end of the first switch module 120 is connected to the first NFC antenna 110. The control module 140 is connected to the first terminal of the second capacitor C2, the second terminal of the second capacitor C2, the first terminal of the first switch module 120, the control terminal of the first switch module 120, and the control terminals of the plurality of second switch modules 150, respectively. For the specific operation process of the NFC communication circuit shown in fig. 7, reference may be made to the above embodiments, and details are not repeated here.

The embodiment of the application provides a casing subassembly, including the casing to and above-mentioned NFC communication circuit, this NFC communication circuit can locate on the casing. It is to be appreciated that portions of the NFC communications circuitry can be disposed on the housing (e.g., attached to a surface of the housing or embedded within the housing) in the same or different arrangements, and the portions can be disposed on the same or different locations of the housing. For example, the first NFC antenna 110 may be embedded within a housing and the application circuit 160 may be attached to a surface of the housing.

The embodiment of the application also provides an NFC communication system which comprises the electronic equipment and the shell assembly. It is understood that the electronic device may be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable wearable devices.

The electronic equipment is provided with a second NFC antenna to radiate NFC radio-frequency signals through the second NFC antenna, and NFC communication is achieved. The first NFC antenna 110 of the housing assembly may be coupled to a second NFC antenna of the electronic device so that energy may be harvested from the electronic device and drive application circuitry 160 disposed on the housing assembly.

In the description herein, references to the description of "some embodiments," "other embodiments," "desired embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, a schematic description of the above terminology may not necessarily refer to the same embodiment or example.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An NFC communications circuit, comprising:

a first NFC antenna for coupling with an external NFC device;

the first switch module is connected with the first NFC antenna;

the resonance module is connected with the first switch module;

2. The NFC communication circuit of claim 1,

the control module is respectively connected with a first output end of the resonance module, a second output end of the resonance module, a first end of the first switch module and a control end of the first switch module, and is used for controlling the switching state of the first switch module according to a first voltage difference between the output voltage of the first output end and the output voltage of the second output end and a second voltage difference between the output voltage of the first output end and the voltage of the first end of the first switch module;

the first end of the first switch module is connected with the first NFC antenna, the second end of the first switch module is connected with the first input end of the resonance module, and the second input end of the resonance module is connected with the first NFC antenna.

3. The NFC communication circuit of claim 2,

the control module is configured to, when the first switch module is turned on, control the first switch module to turn on the connection between the resonance module and the first NFC antenna if the first voltage difference is greater than a first threshold or the first voltage difference is zero, otherwise, control the first switch module to turn off the connection between the resonance module and the first NFC antenna;

the control module is further configured to, when the first switch module is turned off, control the first switch module to turn on the connection between the resonance module and the first NFC antenna if the second voltage difference is zero, and otherwise, control the first switch module to turn off the connection between the resonance module and the first NFC antenna.

4. The NFC communication circuit of claim 2,

the control module is configured to, when the first switch module is turned on, control the first switch module to turn on the connection between the resonance module and the first NFC antenna if the first voltage difference is smaller than a second threshold, and otherwise, control the first switch module to turn off the connection between the resonance module and the first NFC antenna;

5. NFC communication circuit according to one of the claims 2 to 4, characterised in that the resonance module comprises a first and a second capacitance;

a first end of the first capacitor is connected to the first NFC antenna and a first end of the second capacitor, respectively, and a second end of the first capacitor is connected to a second end of the first switch module and a second end of the second capacitor, respectively; and the first end of the second capacitor and the second end of the second capacitor are respectively connected with the control module.

6. NFC communication circuit according to one of the claims 2 to 4, characterised in that the first switching module comprises an electronic switching tube.

7. The NFC communications circuit of claim 2, further comprising a second switching module and an application circuit;

the second switch module is respectively connected with the first output end, the control module and the application circuit, and the application circuit is connected with the second output end;

the control module is further used for controlling the switching state of the second switching module according to the first pressure difference so as to connect or disconnect the application circuit and the resonance module.

8. The NFC communication circuit of claim 7, wherein the number of application circuits is plural, and the number of second switch modules is plural;

the plurality of second switch modules are connected with the plurality of application circuits in a one-to-one correspondence manner, and the plurality of second switch modules are connected with the first output end and the control module.

9. A housing assembly, comprising:

an NFC communications circuit as claimed in any one of claims 1 to 8;

the NFC communication circuit is arranged on the shell.

10. An NFC communication system, comprising:

the housing assembly of claim 9;