CN116663586A

CN116663586A - Circuit for multiplexing wireless charge-SOC chip into NFC chip, control method and electronic equipment

Info

Publication number: CN116663586A
Application number: CN202210148013.8A
Authority: CN
Inventors: 徐杰
Original assignee: Meixinsheng Technology Beijing Co ltd
Current assignee: Meixinsheng Technology Beijing Co ltd
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2023-08-29

Abstract

The application relates to a circuit, a control method and electronic equipment for multiplexing a wireless charge-SOC chip into an NFC chip, which comprises a wireless charge coil, an NFC coil, a coil selection circuit, an NFC demodulation circuit, an NFC signal detection circuit, the wireless charge-SOC chip and an AP main control chip; the wireless charging coil and the NFC coil are respectively connected with a coil selection circuit, the coil selection circuit is respectively connected with a wireless charging SOC chip and an AP main control chip, and the wireless charging SOC chip is connected with the AP main control chip; the wireless charging coil, the NFC demodulation circuit and the NFC signal detection circuit are sequentially connected; the NFC demodulation circuit is connected with the wireless charging SOC chip; the NFC signal detection circuit is connected with the wireless SOC chip and the AP main control chip respectively. According to the application, through the NFC demodulation circuit, the NFC signal detection circuit, the wireless charging SOC chip and the AP main control chip, the wireless charging SOC chip can realize a wireless charging mode and an NFC mode, a plurality of chips are not required to be arranged, so that resources can be saved, and the cost can be reduced.

Description

Circuit for multiplexing wireless charge-SOC chip into NFC chip, control method and electronic equipment

Technical Field

The application belongs to the technical field of electronic equipment, and particularly relates to a circuit for multiplexing a wireless charging SOC chip into an NFC chip, a control method and the electronic equipment.

Background

With the popularization of electronic devices, wireless charging technology is widely used, electromagnetic induction is often adopted in low-power wireless charging, and wireless charging of Qi protocol is widely used in intelligent devices such as mobile phones at present. Qi is a "wireless charging" standard which is introduced by the wireless charging alliance (Wireless Power Consortium, abbreviated as WPC), which is a standardization organization for promoting wireless charging technology for the first time worldwide, and has two major characteristics of convenience and universality. Wireless is fully a transmitting end and a receiving end, and in small-power charging equipment such as a smart watch, the function of the receiving end is usually only provided. The wireless charging SOC chip of the receiving end supports the Qi wireless charging protocol and is applied to products such as intelligent watches, intelligent mobile phones and tablet computers.

Near field communication (Near Field Communication, abbreviated as NFC) is an emerging technology, devices (such as mobile phones) using NFC technology can exchange data in a situation of being close to each other, and the devices are integrated and evolved by non-contact Radio Frequency Identification (RFID) and interconnection technology, and by integrating functions of an inductive card reader, an inductive card and point-to-point communication on a single chip, mobile terminals are utilized to realize applications such as mobile payment, electronic ticketing, access control and the like. The NFC control chip PN80T, for example NXP, PN80T also contains an embedded Security Element (SE).

In the related art, the NFC controller chip and the wireless charging and receiving chip in the current smart watch generally have two functions respectively, which is wasteful in terms of resources, and meanwhile, the cost of the final product is also increased. For small devices such as smart watches NFC functionality is most used in the daily life in card emulation mode. The NFC controller chip and the wireless charging receiving chip have a plurality of modules with similar functions, for example, the two chips contain an ARM Cortex M0 microprocessor core, both use IIC interfaces to communicate with the processor of the AP, both contain rectifier circuit modules, and both transmit ends and receive ends use ASK modulation, thereby causing resource waste.

Disclosure of Invention

In view of the above, the present application aims to overcome the defects of the prior art, and provide a circuit, a control method and an electronic device for multiplexing a wireless charging and SOC chip into an NFC chip, so as to solve the problem in the prior art that many modules with similar functions exist in an NFC controller chip and a wireless charging and receiving chip in the same electronic device, resulting in resource waste.

In order to achieve the above purpose, the application adopts the following technical scheme: a circuit for multiplexing a wireless charge-to-SOC chip into an NFC chip, comprising: the wireless charging coil, the NFC coil, the coil selection circuit, the NFC demodulation circuit, the NFC signal detection circuit, the wireless charging SOC chip and the AP main control chip;

the wireless charging coil and the NFC coil are respectively connected with a coil selection circuit, the coil selection circuit is respectively connected with the wireless charging SOC chip and the AP main control chip, and the wireless charging SOC chip is connected with the AP main control chip;

the NFC coil, the NFC demodulation circuit and the NFC signal detection circuit are sequentially connected;

the NFC demodulation circuit is connected with the wireless charging SOC chip;

the NFC signal detection circuit is respectively connected with the wireless charging SOC chip and the AP main control chip;

when the NFC demodulation circuit outputs a high level, the NFC signal detection circuit is driven to output a low level signal, so that the AP main control chip sends an NFC coil access selection signal to the coil selection circuit, and the coil selection circuit accesses the NFC coil to the wireless charging SOC chip;

when the NFC demodulation circuit outputs a low level, the NFC signal detection circuit is driven to output a high level signal, so that the AP main control chip sends a wireless charging coil access signal to the coil selection circuit, and the coil selection circuit accesses the wireless charging coil to the wireless charging SOC chip.

Further, the method further comprises the following steps:

the voltage converter is respectively connected with the AP main control chip, the wireless charging SOC chip and the battery, and is used for receiving a control signal of the AP main control chip and supplying voltage output by the battery to the wireless charging SOC chip.

Further, the NFC demodulation circuit includes: an envelope detection circuit and a low-pass filter circuit connected with the envelope detection circuit;

the envelope detection circuit is used for acquiring a baseband signal output by the NFC coil;

the low-pass filter circuit is used for performing filter processing on the baseband signal.

Further, the envelope detection circuit includes: the first resistor, the first diode, the second resistor and the first capacitor;

the positive pole of first diode is connected the output of NFC coil, the one end of first resistance is connected to the negative pole of first diode, the one end of second resistance, the one end of first electric capacity are connected respectively to the other end of first resistance, the other end of second resistance and the other end of first electric capacity are all grounded.

Further, the low-pass filter circuit includes: a third resistor and a second capacitor;

one end of the third resistor is connected with the other end of the first resistor, the other end of the third resistor is connected with one end of the second capacitor, and the other end of the second capacitor is grounded.

Further, the NFC signal detection circuit includes: the voltage stabilizing diode, the controllable switch tube and the fourth resistor;

the cathode of the zener diode is connected with the output end of the NFC demodulation circuit, and the anode of the zener diode is grounded;

the control end of the controllable switch tube is connected with the output end of the NFC demodulation circuit, the first end of the controllable switch tube is connected with the fourth resistor, and the second end of the controllable switch tube is grounded.

Further, the wireless charging SOC chip includes: the device comprises a rectifier bridge, a decoding circuit, a timer and a microprocessor;

the rectifier bridge is used for providing working voltage for the decoding circuit, the timer and the microprocessor;

the microprocessor is used for controlling the decoding circuit to adjust decoding parameters so as to correspondingly decode signals output by the wireless charging coil or the NFC coil;

the microprocessor is further used for controlling the timer to enter a PWM mode so as to process the decoded signal and output a modulation baseband signal of NFC.

The embodiment of the application provides electronic equipment, and the wireless charging SOC chip provided by any embodiment is multiplexed into a circuit of an NFC chip.

The embodiment of the application provides a control method for multiplexing a wireless charge-SOC chip into an NFC chip, which comprises the following steps:

receiving signals output by the NFC demodulation circuit and the NFC signal detection circuit;

when the AP main control chip detects that the signal output by the NFC signal detection circuit is converted from high level to low level, the coil selection circuit is driven to connect the NFC coil to the wireless charging SOC chip;

when the wireless charging SOC chip detects that the signal output by the NFC demodulation circuit is at a low level, the NFC signal detection circuit is driven to output a high-level signal, and the AP main control chip drives the coil selection circuit to connect the wireless charging coil to the wireless charging SOC chip according to the high-level signal, so that the wireless charging SOC chip carries out wireless charging on a terminal to which the AP main control chip belongs.

Further, the method further comprises the following steps:

when the wireless charging SOC chip detects that the signal output by the NFC demodulation circuit is at a low level, a wireless charging on signal with the AP main control chip is generated.

Further, after the coil selection circuit accesses the NFC coil to the wireless charging SOC chip, the method further includes:

the wireless charging SOC chip receives the signal output by the NFC coil and decodes the signal; the method specifically comprises the following steps:

acquiring the signal width of the signal and storing the signal width into a buffer area;

splitting the buffer areas according to preset time lengths, accumulating and calculating the signal width in each split buffer area, and determining that the signal is low level if the accumulated signal width in the buffer area is smaller than a first preset threshold value;

if the accumulated signal width is larger than a second preset threshold value, splitting the accumulated signal width in the buffer area by the second preset threshold value to obtain a plurality of data buffer areas;

decoding a plurality of data buffers to obtain data bits;

and judging whether NFC signal transmission is carried out or not according to the data bit.

Further, when the coil selection circuit accesses the NFC coil to the wireless charging SOC chip, the method further includes:

the AP main control chip sends a control signal to a voltage converter, and the voltage converter supplies the voltage output by the battery to the wireless charging SOC chip according to the control signal.

Further, the method further comprises the following steps:

and when NFC data interaction is completed or the NFC data interaction time exceeds the preset time, the AP main control chip sends a wireless charging coil access signal to a coil selection circuit, and the wireless charging coil is accessed to the wireless charging SOC chip.

The embodiment of the application provides electronic equipment, and the control method for multiplexing the wireless charging SOC chip provided by any embodiment into the NFC chip is applied.

By adopting the technical scheme, the application has the following beneficial effects:

the application provides a circuit, a control method and electronic equipment for multiplexing a wireless charge-to-SOC chip into an NFC chip. In addition, the technical scheme provided by the application can provide working voltage for the wireless charging SOC chip through the outside so that the NFC coil can be made smaller.

Drawings

In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a circuit of multiplexing a wireless charge-SOC chip into an NFC chip according to the present application;

FIG. 2 is a schematic diagram of the internal structure of a wireless SOC chip according to the present application;

FIG. 3 is a schematic diagram of a rectifier bridge according to the present application;

fig. 4 is a schematic diagram of a coil selection circuit according to the present application.

FIG. 5 is a schematic diagram illustrating steps of a control method of multiplexing a wireless charge-SOC chip into an NFC chip according to the present application;

FIG. 6 is a schematic diagram of a Qiask baseband and an NFC ASK baseband provided by the present application;

fig. 7 is a schematic diagram illustrating decoding provided by the circuit of the wireless charging SOC chip multiplexing to the NFC chip according to the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail below. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, based on the examples herein, which are within the scope of the application as defined by the claims, will be within the scope of the application as defined by the claims.

The following describes a specific circuit, a control method and an electronic device for multiplexing a wireless charging and discharging chip into an NFC chip according to an embodiment of the present application with reference to the accompanying drawings.

As shown in fig. 1, a circuit for multiplexing a wireless charging chip into an NFC chip according to an embodiment of the present application includes: the wireless charging coil 1, the NFC coil 2, the coil selection circuit 3, the NFC demodulation circuit 4, the NFC signal detection circuit 5, the wireless charging SOC chip 6 and the AP main control chip 7;

the wireless charging coil 1 and the NFC coil 2 are respectively connected with a coil selection circuit 3, the coil selection circuit 3 is respectively connected with the wireless charging SOC chip 6 and the AP main control chip 7, and the wireless charging SOC chip 6 is connected with the AP main control chip 7;

the NFC coil 2, the NFC demodulation circuit 4 and the NFC signal detection circuit 5 are sequentially connected;

the NFC demodulation circuit 4 is connected with the wireless charging SOC chip 6;

the NFC signal detection circuit 5 is respectively connected with the wireless charging SOC chip 6 and the AP main control chip 7;

when the NFC demodulation circuit 4 outputs a high level, the NFC signal detection circuit 5 is driven to output a low level signal, so that the AP main control chip 7 sends a signal for selecting the NFC coil 2 to be connected to the coil selection circuit 3, and the coil selection circuit 3 connects the NFC coil 2 to the wireless charging SOC chip 6;

when the NFC demodulation circuit 4 outputs a low level, the NFC signal detection circuit 5 is driven to output a high level signal, so that the AP main control chip 7 sends a wireless charging coil 1 access signal to the coil selection circuit 3, and the coil selection circuit 3 accesses the wireless charging coil 1 to the wireless charging SOC chip 6.

The working principle of the circuit for multiplexing the wireless charging SOC chip into the NFC chip is that two coils are arranged in the wireless charging system, one coil is a wireless charging coil 1, the other coil is an NFC coil 2, wherein the wireless charging coil 1 is used for wirelessly charging a terminal, and the NFC coil 2 is used for realizing a data interaction function with the terminal. The working frequency of the wireless charging coil 1 is smaller than 200KHz, and the NFC communication working frequency is 13.56MHz. The wireless charging coil 1 is used for outputting one path of AC signal; the NFC coil 2 is used for outputting another path of AC signal; the coil selection circuit 3 is used for selecting one of the two paths of AC signals to output to the wireless charging SOC chip 6 so as to realize a wireless charging function or an NFC data transmission function, and it should be noted that in the technical scheme provided by the application, in order to charge the battery through the wireless charging function under the condition that the terminal product is completely unpowered, the coil selection circuit 3 is selected to be connected to the wireless charging coil by default.

In the application, the NFC demodulation circuit 4 carries out modulation and demodulation on the baseband signal output by the NFC coil 2, outputs an NFC_dmod signal, the NFC_dmod signal is respectively transmitted to the wireless charging SOC chip 6 and the NFC signal detection circuit 5, and the NFC signal detection circuit 5 outputs an NFC_DET signal according to the NFC_dmod signal. When the AP main control chip 7 detects that the NFC_DET signal is converted from high level to low level, the coil_select signal is pulled up, so that the Coil selection circuit 3 selects an NFC Coil 2 access signal, and the NFC Coil 2 is accessed to the wireless charging SOC chip 6; when the nfc_dmod signal is output to be at a low level, the wireless charging SOC chip 6 is in a wireless charging mode, and drives the NFC signal detecting circuit 5 to output a high level signal, so that the AP main control chip 7 sends a wireless charging coil 1 access signal to the coil selecting circuit 3, and the wireless charging coil 1 is accessed to the wireless charging SOC chip 6. For example, when the NFC data transmission is finished, the default wireless charging function is converted.

Specifically, the nfc_det signal is connected to the GPIO port of the AP master control chip 7. When the output of the NFC_dmod signal is low level, when a user puts the wireless charging transmitter, the difference between the NFC_dmod signal and the 13.56MHz resonance point of NFC is relatively large, at the moment, the NFC_dmod signal is low level, the coil selection circuit 3 selects the wireless charging coil 1 to be connected, the wireless charging SOC chip 6 detects the wireless charging AC signal, and the wireless charging conducting signal informs the terminal AP main control chip 7 to realize the wireless charging function. When a user is placed on the NFC transmitter, under the action of the energy field of 13.56MHz, the NFC coil 2 changes the nfc_dmod signal to a high level, the output nfc_det signal changes from the high level to a low level, and if the AP main control chip 7 detects a level change, the user is considered to be placed on the NFC transmitter. By pulling the Coil Select signal high, the NFC Coil 2 is selected to be connected to the wireless charging chip 6.

In some embodiments, as shown in fig. 1, the circuit provided by the present application further includes:

the voltage converter 8 is connected with the AP main control chip 7, the wireless charging SOC chip 6 and the battery 9, and is configured to receive a control signal of the AP main control chip 7, and supply a voltage output by the battery 9 to the wireless charging SOC chip 6.

In some embodiments, since the NFC coil 2 of some electronic devices is relatively small, devices such as smart glasses; when the NFC coil 2 is small, it may not be possible to obtain enough energy from the coil to power the wireless charging SOC chip 6, and at this time, the voltage converter 8 opens the Boost circuit to output 5V from the battery of the terminal to the Vout pin of the wireless charging SOC chip 6, so as to power the wireless charging SOC chip 6. This allows the wireless charging chip 6 to operate without an energy field during ASK modulation, and can easily sample the low level width of the miller code.

In some embodiments, the NFC demodulation circuit 4 includes: an envelope detection circuit 41 and a low-pass filter circuit 42 connected to the envelope detection circuit 41;

the envelope detection circuit 41 is configured to obtain a baseband signal output by the NFC coil 2;

the low-pass filter circuit 42 is configured to perform a filtering process on the baseband signal.

As shown in fig. 1, the envelope detection circuit 41 includes: the first resistor R1, the first diode D1, the second resistor R2 and the first capacitor C1;

the positive pole of first diode D1 is connected the output of NFC coil 2, the one end of first resistance R1 is connected to the negative pole of first diode D1, the one end of second resistance R2, the one end of first electric capacity C1 are connected respectively to the other end of first resistance R1, the other end of second resistance R2 and the other end of first electric capacity C1 are all grounded.

The low-pass filter circuit 42 includes: a third resistor R3 and a second capacitor C2;

one end of the third resistor R3 is connected with the other end of the first resistor R1, the other end of the third resistor R3 is connected with one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

In some embodiments, the NFC signal detection circuit 5 includes: a zener diode D2, a controllable switching tube Q1, and a fourth resistor R4;

the cathode of the zener diode D2 is connected with the output end of the NFC demodulation circuit 4, and the anode of the zener diode D2 is grounded;

the control end of the controllable switch tube Q1 is connected with the output end of the NFC demodulation circuit 4, the first end of the controllable switch tube Q1 is connected with the fourth resistor R1, and the second end of the controllable switch tube Q1 is grounded.

It will be appreciated that the first resistor R1 is used to divide the voltage and the zener diode D2 acts to protect the controllable switch Q1 input. The first resistor R1, the first diode D1, the second resistor R2 and the first capacitor C1 form an envelope detection circuit, and a baseband signal sent by the NFC coil is obtained. The third resistor R3 and the second capacitor C2 form a low-pass filter circuit. When the controllable switch tube Q1 adopts an MOS tube, the grid electrode of the MOS tube is connected with the other end of the third resistor R3, the drain electrode of the MOS tube is connected with the fourth resistor R4, and the source electrode of the MOS tube is grounded.

In some embodiments, as shown in fig. 2, the wireless charging SOC chip 6 includes: a rectifier bridge 61, a decoder circuit 62, a timer 63 and a microprocessor 64;

the rectifier bridge 61 is used for providing working voltages to the decoding circuit 62, the timer 63 and the microprocessor 64;

the microprocessor 64 is used for controlling the decoding circuit 62 to adjust decoding parameters to correspondingly decode signals output by the wireless charging coil 1 or the NFC coil 2;

the microprocessor 64 is further configured to control the timer 63 to enter a PWM mode, so as to process the decoded signal and output a modulated baseband signal of NFC.

Specifically, in the present application, the rectifier bridge 61 is full-bridge rectification, as shown in fig. 3, the rectifier bridge 61 includes a plurality of MOS transistors and corresponding diodes; when the coil area of the rectifier bridge 61 is small NFC and enough energy cannot be obtained from the coil, the boost current is turned on, meanwhile, the MOS tube in the rectifier bridge 61 is enabled to perform full-bridge rectification, working voltage is provided for the decoding circuit 62, the timer 63 and the microprocessor 64, at this time, the wireless charging SOC chip 6 is powered on for resetting, and the internal Cortex M0 microprocessor is started. When the wireless charging SOC chip 6 detects that the nfc_det signal is at a low level, the wireless charging SOC chip 6 switches to an NFC operation mode, and performs NFC card simulation in the NFC operation mode. The wireless charging SOC chip 6 initializes the decoding parameters, and the decoding circuit 62 increases the decoding rate from 2Kbps to 106Kbps in the Qi protocol. In the NFC operation mode, the initialization timer 63 is in a PWM mode, and is used for outputting a modulated baseband signal of NFC, so as to implement NFC communication between the wireless charging SOC chip 6 and the AP main control chip 7. Specifically, the REQA command reply ATQA command in the NFC protocol is received. After entering the APDU communication stage, the wireless charging SOC chip 6 sends a wireless charging on signal to the AP main control chip 7, and enters an NFC data transmission mode.

In some embodiments, the wireless charging SOC chip 6 is connected to the AP master chip 7 through an IIC bus.

Specifically, in the present application, the AP main control chip 7 performs data transceiving with the wireless charging SOC chip 6 through the IIC bus, so as to implement NFC application.

As shown in fig. 4, the coil selection circuit 3 provided by the present application includes:

a first sub-selection circuit 31 and a second sub-selection circuit 32, the first sub-selection circuit 31 being connected in parallel with the second sub-selection circuit 32, wherein the first sub-selection circuit 31 comprises: the first field effect transistor P1A, the third capacitor C3, the fifth resistor R5, the second field effect transistor P1B, the sixth resistor R6, the fourth capacitor C4 and the fifth capacitor C5;

the source electrode of the first field effect transistor P1A is connected to one end of the third capacitor C3, one end of the fifth resistor R5 is connected to the source electrode of the second field effect transistor P1B, the gate electrode of the first field effect transistor P1A is connected to the other end of the third capacitor C3, the other end of the fifth resistor R5 is connected to the gate electrode of the second field effect transistor P1B, the drain electrode of the second field effect transistor P1B is connected to one end of the sixth resistor R6 and one end of the fourth capacitor C4, the other end of the sixth resistor R6 is connected to one end of the fifth capacitor C5, and the other end of the fourth capacitor C4 is connected to the other end of the fifth capacitor C5.

The second sub-selection circuit 32 includes: a third field effect transistor P2A, a sixth capacitor C6, a seventh resistor R7, a fourth field effect transistor P2B, an eighth resistor R8, a seventh capacitor C7, and an eighth capacitor C8;

the source electrode of the third field effect transistor P2A is connected to one end of the sixth capacitor C6 and one end of the seventh resistor R7 and then is connected to the source electrode of the fourth field effect transistor P2B, the gate electrode of the third field effect transistor P2A is connected to the other end of the sixth capacitor C6 and the other end of the seventh resistor R7 and then is connected to the gate electrode of the fourth field effect transistor P2B, the drain electrode of the fourth field effect transistor P2B is connected to one end of the eighth resistor R8 and one end of the seventh capacitor C7, the other end of the eighth resistor R8 is connected to one end of the eighth capacitor C8, and the other end of the seventh capacitor C7 is connected to the other end of the eighth capacitor C8.

The drain of the first fet P1A is connected to the drain of the third fet P2A.

As shown in fig. 5, an embodiment of the present application provides a control method for multiplexing a wireless charging and SOC chip into an NFC chip, where the control method adopts the circuit for multiplexing a wireless charging and SOC chip into an NFC chip provided in any one of the above embodiments, and the control method includes:

s101, receiving signals output by the NFC demodulation circuit 4 and the NFC signal detection circuit 5;

s102, when the AP main control chip 7 detects that the signal output by the NFC signal detection circuit 5 is converted from high level to low level, the coil selection circuit 3 is driven to connect the NFC coil 2 to the wireless charging SOC chip 6;

and S103, when the wireless charging SOC chip 6 detects that the signal output by the NFC demodulation circuit 4 is at a low level, driving the NFC signal detection circuit 5 to output a high-level signal, and driving the coil selection circuit 3 by the AP main control chip 7 according to the high-level signal to access the wireless charging coil (1) to the wireless charging SOC chip 6, so that the wireless charging SOC chip 6 carries out wireless charging on a terminal to which the AP main control chip 7 belongs.

In some embodiments, further comprising:

when the wireless charging SOC chip 6 detects that the signal output by the NFC demodulation circuit 4 is at a low level, a wireless charging on signal with the AP main control chip 7 is generated.

The NFC demodulation circuit 4 outputs an nfc_dmod signal, and the NFC signal detection circuit 5 outputs an nfc_det signal according to the nfc_dmod signal; when a user puts the wireless charging transmitter, the NFC_dmod signal is low level, the wireless charging SOC chip 6 detects that the NFC_dmod signal is low level, the coil selection circuit 3 selects the wireless charging coil 1 to be connected, the wireless charging SOC chip 6 detects the wireless charging AC signal, a wireless charging on signal is generated and sent to the AP main control chip 7, and at the moment, the working mode of the wireless charging SOC chip 6 is wireless charging. When a user is placed on the NFC transmitter, the NFC demodulation circuit 4 outputs an NFC_dmod signal to be high level, the NFC_DET signal is conducted through the controllable switch tube Q1, the high level is changed to be low level, the terminal AP main control chip 7 detects the level change of the high level to be low level, and the user is considered to be placed on the NFC transmitter without receiving a wireless charging conducting signal, the NFC Coil 2 is selectively connected to the wireless charging SOC chip 6 by pulling the coil_select signal high, and when the wireless charging SOC chip 6 detects that the NFC signal detection circuit 5 outputs the low level signal, NFC data transmission between a transmitting end to which the wireless charging SOC chip 6 belongs and a terminal to which the AP main control chip 7 belongs is realized.

As shown in fig. 6, the Qi wireless charging communication baseband signal and the NFC communication baseband signal have a certain difference, but the modulation modes are ASK modulation, the ASK modulation depth sent by the transmitter in the type a mode of NFC is 100%, the baseband is Modified Miller, and the rate is 106Kbit/s. The two Qi wireless charging demodulation circuit parameters are different from those of NFC. The Qi wireless charging and decoding program is used by default by the firmware program in the wireless charging and SOC chip 6, and the wireless charging and SOC chip 6 is notified to enter the NFC communication mode through the IIC bus when the AP main control chip 7 recognizes the NFC mode. The wireless charging SOC chip 6 uses Miller decoding circuitry to communicate NFC protocol commands at the same time. When REQA (Request Command, type A) and Anticolision LOOP completing NFC enter application data transmission, the wireless charging SOC chip 6 sends received data to the AP main control chip 7 through the IIC bus to perform card simulation APDU (Application Protocol Data Unit- -application protocol data unit) application data exchange, and an NFC card simulation function is realized. The application connects the demodulated baseband signal to the dmod pin of the wireless Qi-filling protocol, and obtains the length of bit0 and bit1 by using a decoding circuit of the Qi protocol in the chip.

In some embodiments, after the coil selection circuit 3 connects the NFC coil 2 to the wireless charging SOC chip 6, the method further includes:

the wireless charging SOC chip 6 receives the signal output by the NFC coil 2 and decodes the signal; the method specifically comprises the following steps:

decoding a plurality of data buffers to obtain data bits;

In some embodiments, before storing the signal width of the signal in the buffer, further comprising:

and filtering the signal.

Specifically, as shown in fig. 7, the rectifier bridge 61 includes a pair of MOS transistors and a diode, the wireless charging SOC chip 6 detects a signal output by the NFC demodulation circuit 4, obtains a signal width of the nfc_dmod signal through the internal comparator C, generates a wireless charging on signal, and stores the signal Pause width in the Buffer after receiving the wireless charging on signal. The voltage drop of the body diode in the full-bridge MOS tube is judged by the comparator C in the wireless charging SOC chip 6, so that the working frequency fc of the NFC coil 2 is recovered. As shown in fig. 6, 2 Pause memory units cannot be resolved into 1 bit because there is no groove in the middle of Pause Y. The Pause width buffer needs to be filtered to take account of the possibility of burrs or jitter in the Pause width. The buffer is disassembled into a preset time length of 64/fc, the Pause width of the buffer with the period of 64/fc is accumulated, and if the buffer width is smaller than the first preset threshold value 32/fc, the buffer is considered as a low level Pause.

The method polls the Pause width in the Buffer after the contrast filtering, if the Buffer width is larger than 128/fc us, the Buffer is subtracted by 128/fc us and split into 2 buffers, and the bit width Buffer is obtained. And decoding out bit by bit width Buffer. The specific method is to find the start sequence "sequence Z" first, by polling the Buffer width from the 0 address, and consider it as the start sequence if the first Buffer is low-level Buffer and less than 64/fc and greater than 10/fc time. If the value in the first memory cell is greater than the second cell value and both are less than 8 in the bit width Buffer, then sequence X is considered to be decoded to 1b. If the median value of the bit width Buffer is greater than or equal to 9, decoding into sequence Y and decoding into 0b. If the value in the second memory cell is greater than the first cell value in the bit width Buffer, then it is considered that sequence Z resolves to a start signal. And when the start signal is analyzed, NFC data transmission is carried out.

In some embodiments, when the coil selection circuit 3 connects the NFC coil 2 to the wireless charging SOC chip 6, the method further includes:

the AP main control chip 7 sends a control signal to the voltage converter 8, and the voltage converter 8 supplies the voltage output by the battery 9 to the wireless charging SOC chip 6 according to the control signal.

When the area of the NFC coil 2 is small and the wireless charging SOC chip 6 cannot obtain enough energy from the coil, the boost current is turned on, and meanwhile, the MOS tube in the rectifier bridge is enabled to carry out full-bridge rectification. The application uses the external power supply to supply power to the wireless charging SOC chip 6 when decoding and correcting the miller code, can enable the wireless charging SOC chip 6 to work without an energy field when 100% ASK modulation is performed, and can easily sample the low level width of the miller code.

In some embodiments, further comprising:

when the NFC data interaction is completed or the NFC data interaction time exceeds the preset time, the AP main control chip 7 sends a wireless charging coil 1 access signal to the coil selection circuit 3, and the wireless charging coil 1 is accessed to the wireless charging SOC chip 6.

Specifically, when the NFC communication is finished or overtime, the AP main control chip 7 pulls coil_select low so that the Coil selection circuit 3 connects the wireless charging Coil 1 to the wireless charging SOC chip 6, and resumes the wireless charging mode.

In summary, the application provides a circuit, a control method and electronic equipment for multiplexing a wireless charging and SOC chip into an NFC chip, wherein the circuit comprises a wireless charging coil, an NFC coil, a coil selection circuit, an NFC demodulation circuit, an NFC signal detection circuit, the wireless charging and SOC chip and an AP main control chip; the wireless charging coil and the NFC coil are respectively connected with a coil selection circuit, the coil selection circuit is respectively connected with a wireless charging SOC chip and an AP main control chip, and the wireless charging SOC chip is connected with the AP main control chip; the wireless charging coil, the NFC demodulation circuit and the NFC signal detection circuit are sequentially connected; the NFC demodulation circuit is connected with the wireless charging SOC chip; the NFC signal detection circuit is connected with the wireless SOC chip and the AP main control chip respectively. According to the application, through the NFC demodulation circuit, the NFC signal detection circuit, the wireless charging SOC chip and the AP main control chip, the wireless charging SOC chip can realize a wireless charging mode and an NFC mode, a plurality of chips are not required to be arranged, so that resources can be saved, and the cost can be reduced.

It can be understood that the above-provided control method embodiment corresponds to the above-mentioned circuit embodiment, and the corresponding specific details may be referred to each other and will not be described herein.

It will be appreciated by those skilled in the art that embodiments of the application may be provided as a control method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, magnetic disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of control methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A circuit for multiplexing a wireless charge-to-SOC chip into an NFC chip, comprising: the wireless charging device comprises a wireless charging coil (1), an NFC coil (2), a coil selection circuit (3), an NFC demodulation circuit (4), an NFC signal detection circuit (5), a wireless charging SOC chip (6) and an AP main control chip (7);

the wireless charging coil (1) and the NFC coil (2) are respectively connected with a coil selection circuit (3), the coil selection circuit (3) is respectively connected with the wireless charging SOC chip (6) and the AP main control chip (7), and the wireless charging SOC chip (6) is connected with the AP main control chip (7);

the NFC coil (2), the NFC demodulation circuit (4) and the NFC signal detection circuit (5) are sequentially connected;

the NFC demodulation circuit (4) is connected with the wireless charging SOC chip (6);

the NFC signal detection circuit (5) is respectively connected with the wireless charging SOC chip (6) and the AP main control chip (7);

when the NFC demodulation circuit (4) outputs high level, the NFC signal detection circuit (5) is driven to output low level signals, so that the AP main control chip (7) sends a signal for selecting the access of the NFC coil (2) to the coil selection circuit (3), and the coil selection circuit (3) accesses the NFC coil (2) to the wireless charging SOC chip (6);

when the NFC demodulation circuit (4) outputs a low level, the NFC signal detection circuit (5) is driven to output a high level signal, so that the AP main control chip (7) sends a wireless charging coil (1) access signal to the coil selection circuit (3), and the coil selection circuit (3) accesses the wireless charging coil (1) to the wireless charging SOC chip (6).

2. The circuit of claim 1, further comprising:

the voltage converter (8), voltage converter (8) respectively with AP main control chip (7), wireless charge SOC chip (6) and battery (9) are connected, are used for receiving the control signal of AP main control chip (7), supply the voltage of battery (9) output to wireless charge SOC chip (6).

3. The circuit according to claim 1 or 2, characterized in that the NFC demodulation circuit (4) comprises: an envelope detection circuit (41) and a low-pass filter circuit (42) connected to the envelope detection circuit (41);

the envelope detection circuit (41) is used for acquiring a baseband signal output by the NFC coil;

the low-pass filter circuit (42) is configured to filter the baseband signal.

4. A circuit according to claim 3, characterized in that the envelope detection circuit (41) comprises: a first resistor (R1), a first diode (D1), a second resistor (R2) and a first capacitor (C1);

the positive pole of first diode (D1) is connected the output of NFC coil (2), the one end of first resistance (R1) is connected to the negative pole of first diode (D1), the one end of second resistance (R2), the one end of first electric capacity (C1) are connected respectively to the other end of first resistance (R1), the other end of second resistance (R2) and the other end of first electric capacity (C1) all ground connection.

5. The circuit according to claim 4, wherein the low-pass filter circuit (42) comprises: a third resistor (R3) and a second capacitor (C2);

one end of the third resistor (R3) is connected with the other end of the first resistor (R1), the other end of the third resistor (R3) is connected with one end of the second capacitor (C2), and the other end of the second capacitor (C2) is grounded.

6. The circuit according to claim 1, characterized in that the NFC signal detection circuit (5) comprises: a zener diode (D2), a controllable switching tube (Q1) and a fourth resistor (R4);

the cathode of the zener diode (D2) is connected with the output end of the NFC demodulation circuit (4), and the anode of the zener diode (D2) is grounded;

the control end of the controllable switch tube (Q1) is connected with the output end of the NFC demodulation circuit (4), the first end of the controllable switch tube (Q1) is connected with the fourth resistor (R4) and the second end of the controllable switch tube (Q1) is grounded.

7. The circuit according to claim 2, characterized in that said wireless charging SOC-chip (6) comprises: a rectifier bridge (61), a decoding circuit (62), a timer (63) and a microprocessor (64);

the rectifier bridge (61) is used for providing working voltage for the decoding circuit, a timer and a microprocessor;

the microprocessor (63) is used for controlling the decoding circuit (62) to adjust decoding parameters so as to correspondingly decode signals output by the wireless charging coil (1) or the NFC coil (2);

the microprocessor (64) is further configured to control the timer (63) to enter a PWM mode, so as to process the decoded signal and output a modulated baseband signal of NFC.

8. A control method for multiplexing a wireless charging SOC chip into an NFC chip, wherein the control method employs the circuit according to any one of claims 1 to 8, the control method comprising:

receiving signals output by an NFC demodulation circuit (4) and an NFC signal detection circuit (5);

when the AP main control chip (7) detects that the signal output by the NFC signal detection circuit (5) is converted from high level to low level, the coil selection circuit (3) is driven to connect the NFC coil (2) to the wireless charging SOC chip (6);

when the wireless charging SOC chip (6) detects that the signal output by the NFC demodulation circuit (4) is in a low level, the NFC signal detection circuit (5) outputs a high level signal, the AP main control chip (7) drives the coil selection circuit (3) to access the wireless charging coil (1) to the wireless charging SOC chip (6) according to the high level signal, so that the wireless charging SOC chip (6) carries out wireless charging on a terminal to which the AP main control chip (7) belongs.

9. The control method according to claim 8, characterized by further comprising:

when the wireless charging SOC chip (6) detects that the signal output by the NFC demodulation circuit (4) is at a low level, a wireless charging on signal with the AP main control chip (7) is generated.

10. The control method according to claim 8, characterized by further comprising, after the coil selection circuit (3) has switched in the NFC coil (2) to the wireless charging SOC chip (6):

a wireless charging SOC chip (6) receives signals output by the NFC coil (2) and decodes the signals; the method specifically comprises the following steps:

decoding a plurality of data buffers to obtain data bits;

11. The control method according to claim 8, characterized in that when the coil selection circuit (3) switches the NFC coil (2) on the wireless charging SOC chip (6), it further comprises:

the AP main control chip (7) sends a control signal to the voltage converter (8), and the voltage converter (8) supplies the voltage output by the battery (9) to the wireless charging SOC chip (6) according to the control signal.

12. The control method according to claim 8, characterized by further comprising:

when NFC data interaction is completed or the NFC data interaction time exceeds the preset time, the AP main control chip (7) sends a wireless charging coil (1) access signal to the coil selection circuit (3), and the wireless charging coil (1) is accessed to the wireless charging SOC chip (6).

13. Electronic device, characterized by a circuit applying the wireless charging chip according to any of claims 1-7 multiplexed to an NFC chip.