A wireless transmitting circuit and device with a coding and demodulation identification function

Abstract

The utility model provides a wireless transmitting circuit and device with encoding and demodulation identification function belong to circuit technical field, include: transmitting subcircuit, sampling subcircuit and wireless charging control subcircuit, wherein, transmitting subcircuit is connected with input voltage VEE and sampling subcircuit respectively, wireless charging control subcircuit includes singlechip, the inside of singlechip has operational amplifier, singlechip is connected with input voltage VCC, sampling subcircuit and transmitting subcircuit respectively, singlechip ground connection. Adopt the utility model can ensure that wireless charging product can pass through encoding and identify the identity of the product to be charged to control its wireless charging, can detect and identify metal foreign matter and identify host computer and turn into normal wireless charging, reduce the cost of wireless charging product.

Description

TECHNICAL FIELD

[0001] The utility model relates to a circuit technical field especially relates to a wireless transmitting circuit and device with encoding demodulation identification function. BACKGROUND

[0002] Nowadays, the wireless charging products tend to be universal in appearance, so there is a risk of cross-compatibility between products produced by different manufacturers. In view of this, some manufacturers have begun to design electronic identification functions based on communication coding for identity recognition of wireless charging products, so that the wireless charging products produced by the manufacturers can only charge the power hosts of their own brands, thereby preventing users from mistakenly placing other brands on the wireless charging products produced by the manufacturers for charging, which may lead to out-of-control wireless charging (such as excessive heating due to excessive charging current or too small charging current, device breakdown due to excessive resonance voltage of the receiving circuit, etc.) or even cause danger or accidents.

[0003] However, in the related art, for wireless charging products that need to identify the identity of the product to be charged through communication coding to control charging, the wireless transmitting circuit must have the functions of encoding and decoding and identification, and be able to identify the host and enable the wireless transmitting circuit to switch from the intermittent transmission standby mode of ultra-low power saving to the normal wireless charging mode of continuous transmission, and be able to detect and identify metal foreign objects to prevent inductive heating of metal foreign objects. This is usually achieved by using a special wireless charging transmitting chip with communication protocol function in the wireless charging circuit, which results in a relatively high overall cost of the wireless charging product. SUMMARY

[0004] The main purpose of the utility model is to provide a wireless transmitting circuit and device with encoding demodulation identification function, which can identify the identity of the product to be charged through encoding to control wireless charging, detect and identify metal foreign objects, and identify the host and switch to normal wireless charging, thereby reducing the cost and difficulty of preparing materials for the wireless charging product.

[0005] To achieve the above purpose, the first aspect of the utility model provides a wireless transmitting circuit with encoding demodulation identification function, which comprises a transmitting sub-circuit, a sampling sub-circuit, and a wireless charging control sub-circuit, wherein,

[0006] The transmitting sub-circuit is connected with the input voltage VEE and the sampling sub-circuit, respectively;

[0007] The wireless charging control sub-circuit comprises a single-chip microcomputer, which has an operational amplifier inside, and is connected with the input voltage VCC, the sampling sub-circuit, and the transmitting sub-circuit, respectively, and is grounded.

[0008] In some embodiments, the wireless transmitting circuit further comprises: a voltage stabilizing sub-circuit;

[0009] The voltage stabilizing sub-circuit comprises: a first resistor (R1) and a voltage stabilizing diode (DZ1); one end of the first resistor (R1) is connected with an input voltage VEE, the other end of the first resistor (R1) and the cathode of the voltage stabilizing diode (DZ1) are connected, the cathode of the voltage stabilizing diode (DZ1) is connected with the single-chip microcomputer, the anode of the voltage stabilizing diode (DZ1) is grounded, and the cathode of the voltage stabilizing diode (DZ1) is an input voltage VCC.

[0010] In some embodiments, the wireless transmitting circuit further comprises: an overvoltage protection sub-circuit;

[0011] The voltage input end of the overvoltage protection sub-circuit is connected with an input voltage VDD, the voltage output end VEE of the overvoltage protection sub-circuit is connected with the voltage input end of the transmitting sub-circuit and the voltage input end of the voltage stabilizing sub-circuit respectively, and the voltage output end VCC of the voltage stabilizing sub-circuit is connected with the single-chip microcomputer.

[0012] In some embodiments, the overvoltage protection sub-circuit comprises: an overvoltage protection chip (U1), a first capacitor (C1) and a second capacitor (C2);

[0013] The voltage input end of the overvoltage protection chip (U1) is connected with the input voltage VDD, and the voltage output end VEE of the overvoltage protection chip (U1) is connected with the transmitting sub-circuit and the voltage stabilizing sub-circuit respectively;

[0014] One end of the first capacitor (C1) is connected with the voltage input end of the overvoltage protection chip (U1), and the other end of the first capacitor (C1) is grounded;

[0015] One end of the second capacitor (C2) is connected with the voltage output end VEE of the overvoltage protection chip (U1), and the other end of the second capacitor (C2) is grounded.

[0016] In some embodiments, the transmitting sub-circuit comprises: a second resistor (R2), a third resistor (R3), a resonant circuit and a metal oxide semiconductor field effect transistor (MOS) (Q1);

[0017] The resonant circuit is connected with an input voltage VEE and the drain of the MOS (Q1) respectively;

[0018] One end of the second resistor (R2) is connected with the gate of the MOS (Q1), and the other end of the second resistor (R2) is connected with the PWM port of the single-chip microcomputer;

[0019] One end of the third resistor (R3) is connected with the gate of the MOS tube (Q1), and the other end of the third resistor (R3) is grounded.

[0020] The source of the MOS tube (Q1) is connected with the sampling sub-circuit.

[0021] In some embodiments, the transmitting sub-circuit further comprises a diode (D1).

[0022] The cathode of the diode (D1) is connected with the drain of the MOS tube (Q1), and the anode of the diode is connected with the source of the MOS tube (Q1).

[0023] In some embodiments, the sampling sub-circuit comprises a fourth resistor (R4) and a filtering sub-circuit.

[0024] One end of the fourth resistor (R4) is connected with the transmitting sub-circuit, and the other end of the fourth resistor (R4) is grounded.

[0025] The filtering sub-circuit is connected with the fourth resistor (R4) in parallel, and the filtering sub-circuit is connected with the single-chip microcomputer.

[0026] In some embodiments, the filtering sub-circuit comprises a third capacitor (C3), a fourth capacitor (C4) and a fifth resistor (R5).

[0027] The third capacitor (C3) is connected with the fourth resistor (R4) in parallel.

[0028] One end of the fifth resistor (R5) is connected with one end of the fourth resistor (R4), the other end of the fifth resistor (R5) is connected with the non-inverting input terminal OPAP of the operational amplifier of the single-chip microcomputer and one end of the fourth capacitor (C4), and the other end of the fourth capacitor (C4) is grounded.

[0029] In some embodiments, the wireless transmitting circuit further comprises a non-inverting operational amplification sub-circuit; the non-inverting operational amplification sub-circuit comprises a sixth resistor (R6), a seventh resistor (R7), an eighth resistor (R8) and a fifth capacitor (C5).

[0030] One end of the sixth resistor (R6) is connected with the non-inverting input terminal OPAN of the operational amplifier of the single-chip microcomputer, and the other end of the sixth resistor (R6) is grounded.

[0031] One end of the seventh resistor (R7) is connected with the non-inverting input terminal OPAN of the operational amplifier of the single-chip microcomputer, and the other end of the seventh resistor (R7) is connected with the output terminal OPAO of the operational amplifier of the single-chip microcomputer.

[0032] One end of the eighth resistor (R8) is connected with the operational amplifier output end OPAO of the single-chip microcomputer, the other end of the eighth resistor (R8) is connected with one end of the fifth capacitor (C5), the other end of the fifth capacitor (C5) is grounded.

[0033] To achieve the above object, the second aspect of the utility model provides a wireless transmitting device with encoding and decoding identification function, the wireless transmitting device includes the wireless transmitting circuit provided by the first aspect.

[0034] The utility model discloses a wireless transmitting circuit and device with encoding and decoding identification function, the wireless transmitting circuit includes: transmitting subcircuit, sampling subcircuit and wireless charging control subcircuit, wherein, transmitting subcircuit is connected with input voltage VEE and sampling subcircuit respectively, the wireless charging control subcircuit includes single-chip microcomputer, the inside of single-chip microcomputer has operational amplifier, single-chip microcomputer is connected with input voltage VCC, sampling subcircuit and transmitting subcircuit respectively, and single-chip microcomputer is grounded.

[0035] Thus, the host needing wireless charging receives the signal (transmitting subcircuit is in intermittent transmission state to realize standby low power consumption when standby) transmitted in the transmitting period of transmitting subcircuit through wireless receiving circuit, and coupling feedback is given to transmitting subcircuit with the encoding signal of the host transmission through the transceiving coil. Thus, the single-chip microcomputer continuously outputs the transmitting frequency waveform to the transmitting subcircuit under the condition that the current jump of the sampling subcircuit two ends is detected, and the encoding signal demodulated after the current is amplified by the internal operational amplifier is consistent with the program setting, so that the transmitting subcircuit is switched from intermittent transmission to continuous transmission, thereby the host with wireless receiving circuit is wirelessly charged, otherwise, the single-chip microcomputer continues to make the transmitting subcircuit keep the power saving state of intermittent transmission, so that the host cannot be charged.

[0036] Compared with the mode that the wireless charging control is carried out by using special wireless transmitting chip communication encoding, the single-chip microcomputer with built-in operational amplifier can make the wireless transmitting circuit have the functions of encoding and decoding and identification, so that the wireless charging product based on the wireless transmitting circuit can identify the identity of the product to be charged through encoding to control the wireless charging of the product, and the application of single-chip microcomputer and internal operational amplifier can help to reduce the overall cost and material difficulty of the wireless charging product compared with the use of special wireless transmitting chip.

[0037] In addition, since the utility model has made the wireless transmitting circuit have the functions of encoding and decoding and identification through the single-chip microcomputer combined with the internal operational amplifier, and the metal foreign matter does not generate the encoding signal, so the wireless charging product based on the wireless transmitting circuit can naturally detect and identify the metal foreign matter. BRIEF DESCRIPTION OF DRAWINGS

[0038] The utility model is further described below in combination with the drawings and embodiments, in which:

[0039] Figure 1 The structure schematic diagram of wireless transmitting circuit provided by the utility model in some embodiments;

[0040] Figure 2 The specific structure schematic diagram of voltage stabilizing sub circuit and overvoltage sub circuit related in some embodiments of wireless transmitting circuit provided by the utility model;

[0041] Figure 3 The specific structure schematic diagram of transmitting sub circuit related in some embodiments of wireless transmitting circuit provided by the utility model;

[0042] Figure 4 The specific structure schematic diagram of sampling sub circuit related in some embodiments of wireless transmitting circuit provided by the utility model;

[0043] Figure 5 The specific structure schematic diagram of in-phase operational amplification sub circuit and single-chip microcomputer related in some embodiments of wireless transmitting circuit provided by the utility model. DETAILED DESCRIPTION

[0044] The embodiments of the utility model are described in detail below, and the examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0045] In the description of the utility model, it should be understood that the orientation description, such as the orientation or position relationship of the upper, lower, etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model.

[0046] In the description of the utility model, the plurality refers to two or more. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0047] In the description of the utility model, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.

[0048] Please refer to Figure 1 , Figure 1 The structure schematic diagram of the wireless transmitting circuit provided by the utility model in some embodiments.

[0049] As Figure 1 shown, in some embodiments, the utility model provides a wireless transmitting circuit with encoding and demodulation identification function, which comprises a transmitting sub-circuit, a sampling sub-circuit and a wireless charging control sub-circuit. Among them, the transmitting sub-circuit is connected with input voltage VEE and the sampling sub-circuit respectively; the wireless charging control sub-circuit comprises a single-chip microcomputer, the single-chip microcomputer is internally provided with an operational amplifier, the single-chip microcomputer is connected with input voltage VCC, the sampling sub-circuit and the transmitting sub-circuit respectively, and the single-chip microcomputer is grounded.

[0050] It should be noted that the encoding can be pre-set in the single-chip microcomputer through a program, and the encoding is used to identify the identity of the host allowed to perform wireless charging. It should be understood that the encoding set in the single-chip microcomputer through the program can of course be different based on different design needs of actual applications, and the utility model does not limit the specific type and content of the encoding.

[0051] In addition, the host needing wireless charging is provided with a wireless receiving circuit, and the CPU of the host drives the electronic device (such as a switching tube of a series capacitor, which controls the current change of detuning and resonance by whether the series capacitor is inserted into the wireless receiving loop; or such as a constant current charging management chip with a switching pin, which controls the load current change by controlling the opening and closing of the charging switching pin through the CPU). By controlling the load current change of the wireless charging receiving loop through the CPU of the host, the load consumption current and the whole machine current of the wireless transmitting circuit can be changed, so that the wireless transmitting circuit presents the whole machine current change synchronized with the communication encoding.

[0052] The wireless transmitting circuit is in an intermittent transmitting state to realize standby low power consumption in ordinary times. The host needing wireless charging receives the signal transmitted by the transmitting sub-circuit in the wireless transmitting circuit during the transmitting period through the wireless receiving circuit, and couples the encoding signal to the transmitting sub-circuit through the receiving coil in the wireless charging circuit. In this way, when the single-chip microcomputer of the wireless transmitting circuit detects that there is a current jump at both ends of the sampling sub-circuit, and the encoding signal demodulated after the current is amplified by the operational amplifier in the single-chip microcomputer is consistent with the program setting, the single-chip microcomputer continuously outputs the transmitting frequency waveform to the transmitting sub-circuit, so that the transmitting sub-circuit changes from intermittent transmission to continuous transmission, thereby performing wireless charging on the host with the wireless receiving circuit, otherwise, the single-chip microcomputer continues to keep the transmitting sub-circuit in the power saving state of intermittent transmission, so that the host cannot be charged.

[0053] Please refer to Figure 2 ,Figure 2 The specific structure diagram of the voltage stabilizing sub-circuit and the overvoltage sub-circuit involved in the wireless transmitting circuit provided by the utility model in some embodiments is shown in the figure;

[0054] As shown in the figure, the wireless transmitting circuit provided by the utility model in some embodiments further comprises a voltage stabilizing sub-circuit. Figure 2 The voltage stabilizing sub-circuit comprises a first resistor R1 and a voltage stabilizing tube DZ1; one end of the first resistor R1 is connected with an input voltage VEE, the other end of the first resistor R1 and the cathode of the voltage stabilizing tube DZ1 are connected, the cathode of the voltage stabilizing tube DZ1 is connected with the single-chip microcomputer, the anode of the voltage stabilizing tube DZ1 is grounded, and the cathode of the voltage stabilizing tube DZ1 is the input voltage VCC.

[0055] In addition, the wireless transmitting circuit provided by the utility model can further be connected in parallel with a capacitor C7 and the voltage stabilizing tube DZ1. Figure 2 As shown in the figure, one end of the capacitor C7 is connected with the cathode of the voltage stabilizing tube DZ1, and the other end of the capacitor C7 is grounded.

[0056] The wireless transmitting circuit supplies power to the single-chip microcomputer after the external power supply is stabilized to 5.1V by the first resistor R1 and the voltage stabilizing tube DZ1 through the voltage stabilizing sub-circuit.

[0057] It should be noted that the first resistor R1 functions as a current limiter before the single-chip microcomputer, and the first resistor R1 can specifically be a 0603 chip resistor of 10Ω. In addition, the capacitor C7 can specifically be a 10uF chip capacitor with a voltage resistance of 16V or above, and the voltage stabilizing tube DZ1 can specifically be a voltage stabilizing tube of 5.1V and 1 / 2W.

[0058] It should be noted that the input voltage comprises the power supply voltage VCC, VEE and VDD.

[0059] As shown in the figure, the wireless transmitting circuit provided by the utility model in some embodiments further comprises an overvoltage protection sub-circuit. Figure 2 The voltage input end of the overvoltage protection sub-circuit is connected with the input voltage VDD, the voltage output end VEE of the overvoltage protection sub-circuit is connected with the voltage input end of the transmitting sub-circuit and the voltage stabilizing sub-circuit respectively, and the voltage output end VCC of the voltage stabilizing sub-circuit is connected with the single-chip microcomputer.

[0060] In the wireless transmitting circuit, the overvoltage protection sub-circuit ensures that the input voltage VDD exceeds 6.1V or the current exceeds 2.5A, so that the power supply can be automatically cut off, thereby protecting the devices of other circuits behind from being damaged due to overcurrent or overvoltage.

[0061] As shown in the figure, the wireless transmitting circuit provided by the utility model in some embodiments further comprises an overvoltage protection sub-circuit.

[0062] Figure 2 ​As shown in the figure, in some embodiments, the overvoltage protection subcircuit comprises: an overvoltage protection chip U1, a first capacitor C1 and a second capacitor C2. Among them, the voltage input end of the overvoltage protection chip U1 is connected with the input voltage VDD, and the voltage output end VEE of the overvoltage protection chip U1 is connected with the transmitting subcircuit and the voltage stabilizing subcircuit respectively; one end of the first capacitor C1 is connected with the voltage input end of the overvoltage protection chip U1, and the other end of the first capacitor C1 is grounded; one end of the second capacitor C2 is connected with the voltage output end VEE of the overvoltage protection chip U1, and the other end of the second capacitor C2 is grounded.

[0063] In the wireless transmitting circuit, the input voltage VDD exceeding 6.1V or the current exceeding 2.5A can be automatically powered off through the overvoltage protection chip U1, and the wireless transmitting circuit further filters the noise in the power supply through the first capacitor C1 and the second capacitor C2.

[0064] The external power supply provided by the input voltage VDD is supplied to the single-chip microcomputer after being stabilized to 5.1V through the overvoltage protection chip U1 in the overvoltage protection subcircuit, the first resistor R1 and the voltage stabilizing tube DZ1 in the wireless transmitting circuit.

[0065] It should be noted that the overvoltage protection chip U1 can be selected from an overvoltage protection chip with a working voltage range of not less than 4V-36V, a current resistance of 2A or more, and an overvoltage protection voltage of 6.1V, such as SA8205 and the like. In addition, the first capacitor C1 can be selected as a 100nF patch capacitor, and the second capacitor C2 can be selected as a 10uF patch capacitor with a voltage resistance of 16V or more.

[0066] Please refer to Figure 3 , Figure 3 The specific structure diagram of the transmitting subcircuit involved in the wireless transmitting circuit provided by the utility model in some embodiments.

[0067] As shown in the figure, Figure 3 In some embodiments, the transmitting subcircuit of the wireless transmitting circuit provided by the utility model comprises: a second resistor R2, a third resistor R3, a resonant circuit and a MOS tube Q1. Among them, the resonant circuit is connected with the input voltage VEE and the drain of the MOS tube Q1 respectively, one end of the second resistor R2 is connected with the gate of the MOS tube Q1, the other end of the second resistor R2 is connected with the PWM port of the single-chip microcomputer, one end of the third resistor R3 is connected with the gate of the MOS tube Q1, the other end of the third resistor R3 is grounded, and the source of the MOS tube Q1 is connected with the sampling subcircuit.

[0068] As shown in the figure, Figure 3As shown in some embodiments, the resonance loop can be composed of the capacitor C6 and the transmitting coil L1. And, the wireless transmitting circuit provided by the utility model further can access the capacitor C8 at the voltage input end VEE of the resonance loop composed of the capacitor C6 and the transmitting coil L1. Namely: one end of the capacitor C8 is connected with the voltage input end VEE of the resonance loop, and the other end of the capacitor C8 is grounded.

[0069] In the wireless transmitting circuit, the PWM port of the single-chip microcomputer outputs a transmitting frequency waveform to drive the MOS tube Q1 to turn on and off according to the frequency and duty cycle of pulse width modulation (PWM), the resonance loop composed of the capacitor C6 and the transmitting coil L1 is the load of the MOS tube Q1, the resonance loop composed of the capacitor C6 and the transmitting coil L1 generates a high-voltage oscillation waveform with the same frequency as the PWM frequency at both ends, and transmits the high-voltage oscillation waveform to the outside through the transmitting coil L1. In addition, the capacitor C8 is used to provide a filtering channel between the input voltage VEE of the wireless transmitting circuit and the ground to filter out noise signals in the VEE.

[0070] It should be noted that the second resistor R2 can be specifically selected as a 0603 chip resistor of 10Ω, the third resistor R3 can be specifically selected as 4.7K-10K, the capacitor C8 can be specifically selected as a 10uF chip capacitor with a withstand voltage of 16V or more, for the wireless charging transmitting circuit with a transmitting frequency of 125KHz-145KHz, the capacitor C6 can be specifically selected as an NPO chip capacitor with a withstand voltage of 100V and a capacitance of 100nF±5%, the transmitting coil L1 can be selected as a multi-strand winding coil with an inductance of 4uH-5uH and an outer diameter of about 20mm, and the specific inductance is selected according to actual debugging. The MOS tube Q1 can be specifically selected as an N-channel MOSFET tube with a VDS withstand voltage of ≥60V and a current resistance of 3A or more, such as NCE6003M, NCE6003Y and the like.

[0071] As shown in some embodiments, the wireless transmitting circuit further comprises a diode D1. Figure 3 As shown in some embodiments, the wireless transmitting circuit further comprises a diode D1.

[0072] The wireless transmitting circuit uses the diode D1 as a reverse protection diode of the MOS tube Q1, so as to provide reverse current protection for the MOS tube Q1 when the MOS tube Q1 is turned off, thereby preventing the MOS tube Q1 from being damaged.

[0073] It should be noted that the diode D1 can be specifically selected as a Schottky fast diode such as IN5819W.

[0074] Please refer to Figure 4 , Figure 4The wireless transmitting circuit provided by the utility model relates to a specific structure diagram of a sub-circuit in some embodiments.

[0075] As Figure 4 shown, in some embodiments, the sub-circuit of the wireless transmitting circuit provided by the utility model comprises a fourth resistor R4 and a filter sub-circuit.

[0076] In some embodiments, the filter sub-circuit comprises a third capacitor C3, a fourth capacitor C4 and a fifth resistor R5.

[0077] In the wireless transmitting circuit, the fourth resistor R4, the third capacitor C3, the fifth resistor R5 and the fourth capacitor C4 form the sub-circuit, the working current of the wireless transmitting circuit generates a voltage drop across the fourth resistor R4, and after one-stage filtering by the third capacitor C3 and two-stage filtering by the fifth resistor R5 and the fourth capacitor C4, the current is sent to the single-chip microcomputer for amplification.

[0078] It should be noted that the fourth resistor R4 can be specifically selected as a 0.22Ω±1% 1210 patch precision resistor, and the fifth resistor R5 can be specifically selected as a 1K±1% 0603 patch precision resistor.

[0079] Please refer to Figure 5 , Figure 5 The specific structure diagram of the in-phase operational amplification sub-circuit and the single-chip microcomputer involved in the wireless transmitting circuit provided by the utility model in some embodiments.

[0080] As Figure 5As shown, in some embodiments, the wireless transmitting circuit further includes: a same-phase operational amplifier sub-circuit; the same-phase operational amplifier sub-circuit includes: a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a fifth capacitor C5; wherein one end of the sixth resistor R6 is connected with an inverting input end OPAN of the single-chip microcomputer, and the other end of the sixth resistor R6 is grounded; one end of the seventh resistor R7 is connected with an operational amplifier inverting input end OPAN of the single-chip microcomputer, and the other end of the seventh resistor R7 is connected with an operational amplifier output end OPAO of the single-chip microcomputer; one end of the eighth resistor R8 is connected with the operational amplifier output end OPAO of the single-chip microcomputer, and the other end of the eighth resistor R8 is connected with one end of the fifth capacitor C5, and the other end of the fifth capacitor C5 is grounded.

[0081] In the wireless transmitting circuit, the operational amplifier in the single-chip microcomputer U2, together with the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the fifth capacitor C5, constitutes a same-phase operational amplifier sub-circuit, to amplify the small-amplitude coded signal obtained by the sampling sub-circuit, and the amplification multiple = 1+R7 / R6, and the amplification multiple is determined by the seventh resistor R7 connected between the operational amplifier same-phase input end OPAP (pin 6) and the operational amplifier output end OPAO (pin 5) of the single-chip microcomputer U2, and the sixth resistor R6 connected between the operational amplifier inverting input end OPAN (pin 7) of the single-chip microcomputer U2 and the ground. The coded voltage waveform output by the operational amplifier output end OPAO of the single-chip microcomputer U2 is sent to the AD port or the I / O port (pin 3) of the single-chip microcomputer U2 for detection, to identify whether it is consistent with the code set by the internal program of the single-chip microcomputer U2, if yes, the PWM port (pin 4) of the single-chip microcomputer U2 continuously outputs the transmitting drive waveform, otherwise, it returns to the original intermittent transmitting state of ultra-low power consumption.

[0082] It should be noted that the sixth resistor R6 can be specifically selected from a 1K±1% 0603 precision resistor, the seventh resistor R7 can be specifically selected from a 20K±1% 0603 precision resistor, and the eighth resistor R8 can be specifically selected from a 100Ω 0603 resistor. The fifth capacitor C5 can be specifically selected from a 100nF capacitor, and the single-chip microcomputer U2 can be selected from a single-chip microcomputer with a working voltage not less than 2.5V-5.5V, 12-bit ADC, internal operational amplifier and PWM, and internal memory of more than 3K, such as an MC32F7062 model.

[0083] The wireless transmitting circuit provided by the utility model, when in the signal transmitting period, the wireless receiving circuit of the host computer which needs to be wirelessly charged can receive the transmitting signal, and the encoding signal transmitted by the host computer is coupled and fed back to the transmitting sub-circuit through the transmitting and receiving coil. The wireless receiving circuit of the host computer can generate load current variation with the encoding change, and through the mutual coupling of the transmitting and receiving coils, the whole machine current of the wireless transmitting circuit can also present current variation synchronized with the communication encoding, so that the voltage variation synchronized with the communication encoding can be generated at the two ends of the fourth resistor R4 in the sub-circuit, in order to reduce the influence of the fourth resistor R4 on the transmitting power, the resistance value of the fourth resistor R4 is usually small, so as to reduce the power consumption, and therefore the voltage waveform at the two ends of the fourth resistor R4 is also small. Therefore, the wireless transmitting circuit is amplified by the in-phase operational amplifier sub-circuit, so that the voltage variation amplitude which can be recognized by the single-chip microcomputer U2 is obtained, and then the single-chip microcomputer U2 reads and recognizes.

[0084] The wireless transmitting circuit is in the intermittent transmitting state when waiting, so as to realize low power consumption in standby. When the wireless transmitting circuit is in the signal transmitting period, if the single-chip microcomputer U2 of the transmitting circuit detects that the current jump at the two ends of the fourth resistor R4 is consistent with the program setting after the encoding signal is demodulated after amplification, the single-chip microcomputer U2 continuously outputs the transmitting frequency waveform based on PWM, so that the wireless transmitting circuit is switched from intermittent transmission to continuous transmission, and the host computer is wirelessly charged, otherwise, the wireless transmitting circuit continues to keep the power saving state of intermittent transmission, so that the host computer cannot be charged.

[0085] Compared with the mode that the communication encoding of the special wireless transmitting chip is used to control the wireless charging, the wireless transmitting circuit can have the functions of encoding decoding and recognition only by the single-chip microcomputer with the built-in operational amplifier, so that the wireless charging product based on the wireless transmitting circuit can recognize the identity of the product to be charged by the encoding, so as to control the wireless charging, and compared with the special wireless transmitting chip, the application of the single-chip microcomputer and the internal operational amplifier can help to reduce the overall cost and material difficulty of the wireless charging product.

[0086] In addition, since the wireless transmitting circuit has the functions of encoding decoding and recognition by the single-chip microcomputer combined with the internal operational amplifier, and the metal foreign matter cannot generate the encoding signal, so the wireless charging product based on the wireless transmitting circuit can also detect and recognize the metal foreign matter.

[0087] The utility model also relates to a wireless transmitting device with encoding demodulation recognition function, and the wireless transmitting device is provided with the wireless transmitting circuit of the above embodiment, so that the wireless transmitting device can realize the same operation process as the above wireless transmitting circuit. The specific embodiment of the wireless transmitting device will not be described here.

[0088] The utility model embodiment has been explained in detail above in combination with the drawings, but the utility model is not limited to the above-mentioned embodiment, still can make various changes in the knowledge range of the ordinary skill of the people in the prior art within the premise of not departing from the utility model's tenet.

Claims

1. A wireless transmitting circuit with a band-coded demodulation identification function, characterized by comprising: The wireless transmitting circuit comprises a transmitting sub-circuit, a sampling sub-circuit and a wireless charging control sub-circuit, wherein, The transmitting sub-circuit is connected with the input voltage VEE and the sampling sub-circuit respectively; The wireless charging control sub-circuit comprises a single-chip microcomputer, the single-chip microcomputer is internally provided with an operational amplifier, and the single-chip microcomputer is connected with the input voltage VCC, the sampling sub-circuit and the transmitting sub-circuit respectively, and the single-chip microcomputer is grounded.

2. The wireless transmit circuit of claim 1, wherein, The wireless transmitting circuit further comprises a voltage stabilizing sub-circuit; The voltage stabilizing sub-circuit comprises a first resistor (R1) and a voltage stabilizing tube (DZ1), one end of the first resistor (R1) is connected with the input voltage VEE, the other end of the first resistor (R1) and the cathode of the voltage stabilizing tube (DZ1) are connected, the cathode of the voltage stabilizing tube (DZ1) is connected with the single-chip microcomputer, the anode of the voltage stabilizing tube (DZ1) is grounded, and the cathode of the voltage stabilizing tube (DZ1) is the input voltage VCC.

3. The wireless transmit circuit of claim 2, wherein, The wireless transmitting circuit further comprises an overvoltage protection sub-circuit; The voltage input end of the overvoltage protection sub-circuit is connected with the input voltage VDD, the voltage output end VEE of the overvoltage protection sub-circuit is connected with the voltage input end of the transmitting sub-circuit and the voltage input end of the voltage stabilizing sub-circuit respectively, and the voltage output end VCC of the voltage stabilizing sub-circuit is connected with the single-chip microcomputer.

4. The wireless transmit circuit of claim 3, wherein, The overvoltage protection sub-circuit comprises an overvoltage protection chip (U1), a first capacitor (C1) and a second capacitor (C2); The voltage input end of the overvoltage protection chip (U1) is connected with the input voltage VDD, and the voltage output end VEE of the overvoltage protection chip (U1) is connected with the transmitting sub-circuit and the voltage stabilizing sub-circuit respectively; One end of the first capacitor (C1) is connected with the voltage input end of the overvoltage protection chip (U1), and the other end of the first capacitor (C1) is grounded; One end of the second capacitor (C2) is connected with the voltage output end VEE of the overvoltage protection chip (U1), and the other end of the second capacitor (C2) is grounded.

5. The wireless transmit circuit of claim 1, wherein, The transmitting sub-circuit comprises a second resistor (R2), a third resistor (R3), a resonance circuit and a metal oxide semiconductor field effect transistor (MOS) (Q1); The resonance circuit is connected with the input voltage VEE and the drain of the MOS (Q1) respectively; One end of the second resistor (R2) is connected with the gate of the MOS (Q1), and the other end of the second resistor (R2) is connected with the PWM port of the single-chip microcomputer; One end of the third resistor (R3) is connected with the gate of the MOS (Q1), and the other end of the third resistor (R3) is grounded; The source of the MOS (Q1) is connected with the sampling sub-circuit.

6. The wireless transmit circuit of claim 5, wherein, The transmitting sub-circuit further comprises a diode (D1); The cathode of the diode (D1) is connected with the drain of the MOS (Q1), and the anode of the diode is connected with the source of the MOS (Q1).

7. The wireless transmit circuit of claim 1, wherein, The sampling sub-circuit comprises a fourth resistor (R4) and a filtering sub-circuit; One end of the fourth resistor (R4) is connected with the transmitting sub-circuit, and the other end of the fourth resistor (R4) is grounded. The filter sub-circuit is connected in parallel with the fourth resistor (R4), and the filter sub-circuit is connected with the single-chip microcomputer.

8. The wireless transmit circuit of claim 7, wherein, The filter sub-circuit comprises a third capacitor (C3), a fourth capacitor (C4) and a fifth resistor (R5). The third capacitor (C3) is connected in parallel with the fourth resistor (R4). One end of the fifth resistor (R5) is connected with one end of the fourth resistor (R4), the other end of the fifth resistor (R5) is connected with the OPAP of the single-chip microcomputer and one end of the fourth capacitor (C4), and the other end of the fourth capacitor (C4) is grounded.

9. The wireless transmit circuit of any one of claims 1 to 8, wherein, The wireless transmitting circuit further comprises a same-phase operational amplification sub-circuit, and the same-phase operational amplification sub-circuit comprises a sixth resistor (R6), a seventh resistor (R7), an eighth resistor (R8) and a fifth capacitor (C5). One end of the sixth resistor (R6) is connected with the OPAN of the single-chip microcomputer, and the other end of the sixth resistor (R6) is grounded. One end of the seventh resistor (R7) is connected with the OPAN of the single-chip microcomputer, and the other end of the seventh resistor (R7) is connected with the OPAO of the single-chip microcomputer. One end of the eighth resistor (R8) is connected with the OPAO of the single-chip microcomputer, the other end of the eighth resistor (R8) is connected with one end of the fifth capacitor (C5), and the other end of the fifth capacitor (C5) is grounded.

10. A wireless transmitting apparatus with a band-coded demodulation identification function, characterized by comprising: The wireless transmitting device comprises the wireless transmitting circuit according to any one of claims 1 to 9.

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