Impedance matching circuit, related circuit and circuit system

Abstract

The invention relates to an impedance matching circuit, a related circuit and a circuit system. The impedance matching circuit is connected between a signal source circuit and a surface acoustic wave chip, and comprises an MCU controller, a temperature measurement circuit and an impedance matching network, the impedance matching network comprises a matching inductor combination and a matching capacitor combination, the matching inductor combination comprises a plurality of matching inductors which are connected in series and have different inductance values, and an inductor switch which is connected in parallel to each matching inductor; the matching inductor combination comprises a plurality of matching capacitors which are connected in parallel and have different capacitance values, and a capacitor switch which is connected in series with each matching capacitor; the temperature measuring circuit is connected with the MCU controller and is used for measuring temperature data of the surface acoustic wave chip in real time and sending the temperature data to the MCU controller; and the MCU controller is connected with each inductance switch and each capacitance switch and is used for outputting a control signal according to the received temperature data so as to control the corresponding inductance switches and capacitance switches to be switched off or switched on.

Description

Technical Field

[0001] The invention belongs to the technical field of surface acoustic wave device driving, and in particular relates to an impedance matching circuit, a related circuit and a circuit system. Background Art

[0002] The surface acoustic wave chip is mainly composed of a piezoelectric substrate and an interdigital transducer (IDT) made of metal thin film on the polished surface of the piezoelectric substrate. By applying a high-frequency AC signal (MHz-GHz) to the IDT through a signal source circuit, a surface acoustic wave (SAW) can be excited on the substrate surface and propagated along the surface of the piezoelectric substrate. When the surface acoustic wave encounters a liquid on its transmission path, it will further radiate acoustic wave energy to the liquid in the form of a longitudinal pressure wave due to the acoustic impedance difference between the liquid and the solid, thereby forming a surface acoustic wave acoustic streaming effect in the liquid. This special effect has been used to derive a series of fluid-driven applications, such as microfluid atomization, droplet injection, solution mixing, cell fusion and separation, particle arrangement and sorting, etc.

[0003] As a driving element, the surface acoustic wave chip has its own particularity. On the one hand, due to the inherent material properties of piezoelectric materials, there are mechanical losses and dielectric losses during the working process, which gradually increase the temperature of the device; on the other hand, when the surface acoustic wave interacts with the fluid, part of the energy will be lost due to the viscosity loss of the liquid and converted into heat. The heat in the liquid is transferred to the surface acoustic wave device, which will cause further temperature rise.

[0004] If the signal source circuit is directly connected to the SAW chip, there will be a large degree of impedance mismatch, resulting in large power reflection, so that the energy output by the power source cannot be fully absorbed by the load, greatly reducing its energy transmission efficiency. In order to ensure that the SAW chip maintains its driving capability, it is necessary to further increase the output power of the signal source circuit, which brings great burden and challenges to the signal source circuit. As the output power of the signal source circuit increases, the heat loss becomes more and more serious. Affected by temperature, the performance of the signal source circuit decreases rapidly, causing the output alternating voltage signal to decay rapidly, thereby affecting the load driving capability of the signal source circuit and reducing the driving capability of the SAW chip. Summary of the invention

[0005] In view of the technical defects and technical drawbacks existing in the prior art, the embodiments of the present disclosure provide an impedance matching circuit, related circuits and circuit systems that overcome the above problems or at least partially solve the above problems.

[0006] As a first aspect of an embodiment of the present disclosure, it relates to an impedance matching circuit connected between a signal source circuit and a surface acoustic wave chip, wherein the impedance matching circuit includes an MCU controller, a temperature measurement circuit and an impedance matching network;

[0007] The impedance matching network includes a matching inductor combination and a matching capacitor combination, wherein the matching inductor combination includes a plurality of matching inductors of different inductances connected in series, and an inductor switch connected in parallel to each matching inductor; the matching inductor combination includes a plurality of matching capacitors of different capacitances connected in parallel, and a capacitor switch connected in series to each matching capacitor;

[0008] The temperature measurement circuit is connected to the MCU controller, and is used to measure the temperature data of the surface acoustic wave chip in real time and send the data to the MCU controller;

[0009] The MCU controller is connected to each of the inductance switches and each of the capacitance switches respectively, and is used to output a control signal according to the received temperature data to control the corresponding inductance switches and capacitance switches to be opened or closed.

[0010] In one or some optional embodiments, the MCU controller is specifically used to determine the real-time impedance of the surface acoustic wave chip based on the received temperature data and a pre-configured temperature and impedance matching relationship table, and calculate the inductance and capacitance of the impedance to be matched based on the following impedance calculation formula according to the impedance of the signal source circuit and the real-time impedance of the surface acoustic wave chip:

[0011]

[0012] in,

[0013]

[0014] Z M =Z I +X L *i, formula 5;

[0015] The impedance of the signal source circuit is Z I =R I +X I *i, where R I is the real part of the signal source impedance, X I is the imaginary part of the signal impedance;

[0016] The current impedance of the SAW chip is Z O =R O +X O *i, where R O is the real part of the impedance of the SAW chip, X Ois the imaginary part of the impedance of the SAW chip;

[0017] L is the inductance of the impedance to be matched, C is the capacitance of the impedance to be matched, and f is the operating frequency of the surface acoustic wave chip;

[0018] At least one matching capacitor and matching inductor that need to be connected is determined according to the inductance and capacitance of the impedance to be matched, and the control signal is determined and output according to the at least one matching capacitor and matching inductor that need to be connected.

[0019] In one or some optional embodiments, the matching inductor combination includes four matching inductors and four inductor switches; the matching inductor combination includes four matching capacitors and four capacitor switches;

[0020] The values ​​of the four matching inductors are and

[0021] The values ​​of the four matching capacitors are and

[0022] Among them, L M and C M The value of is calculated based on the impedance calculation formula according to the impedance of the signal source circuit and the maximum impedance of the surface acoustic wave chip.

[0023] In one or some optional embodiments, the temperature measurement circuit includes a DC power supply, a thermistor, a current limiting resistor, a compensation resistor and a measurement circuit;

[0024] The DC power supply, current limiting resistor and thermistor are connected in sequence;

[0025] The compensation resistor is connected in parallel with the thermistor and is grounded;

[0026] The measuring circuit is connected between the current limiting resistor and the thermistor, and is used for measuring the voltage signal in real time, converting the voltage signal into temperature data of the surface acoustic wave chip, and sending the data to the MCU controller.

[0027] As a second aspect of the embodiments of the present disclosure, it relates to a surface acoustic wave chip driving circuit, comprising a signal source circuit and the above-mentioned impedance matching circuit;

[0028] The signal source circuit is connected to the impedance matching circuit and is used to provide a high-frequency AC signal.

[0029] In one or some optional embodiments, the signal source circuit includes a high-frequency signal generating circuit, a signal processing circuit and a power amplifier matching circuit connected in sequence;

[0030] The high-frequency signal generating circuit is used to output a high-frequency square wave signal;

[0031] The signal processing circuit is used to process the high-frequency square wave signal to obtain a processed high-frequency square wave signal;

[0032] The power amplifier matching circuit is used to amplify the power of the processed high-frequency square wave signal to obtain a power-amplified high-frequency square wave signal, and filter the power-amplified high-frequency square wave signal to obtain a high-frequency AC signal.

[0033] In one or some optional embodiments, the power amplifier matching circuit includes a MOS tube, a choke inductor, a parallel capacitor, a resonant inductor and a resonant capacitor;

[0034] The gate of the MOS tube is connected to the output end of the signal processing circuit, the drain of the MOS tube is respectively connected to the choke inductor, the shunt capacitor and the resonant inductor, the source of the MOS tube is grounded, the other end of the choke inductor is connected to the input voltage, the other end of the shunt capacitor is grounded, the other end of the resonant inductor is connected to the resonant capacitor, and the other end of the resonant capacitor is used to output the high-frequency AC signal;

[0035] The duty cycle of the processed high-frequency square wave signal input to the gate of the MOS tube is 0.5.

[0036] In one or some optional embodiments, the minimum value of the choke inductance L1 is calculated by the following formula 6:

[0037]

[0038] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, L1 represents the minimum value of the choke inductance L1, and f represents the frequency of the high-frequency AC voltage signal;

[0039] The value of the parallel capacitor C1 is calculated by the following formula 7:

[0040]

[0041] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, C1 represents the value of the parallel capacitor C1, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, f represents the frequency of the high-frequency AC voltage signal;

[0042] The value of the resonant inductor L2 is calculated by the following formula 8:

[0043]

[0044] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, L2 represents the value of the resonant inductor L2, Q L represents the quality factor of the LC series resonant circuit, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, f represents the frequency of the high-frequency AC voltage signal;

[0045] The value of the resonant capacitor C2 is calculated by the following formula 9:

[0046]

[0047] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, C2 represents the value of the resonant capacitor C2, L2 represents the value of the resonant inductor L2, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, and f represents the frequency of the high-frequency AC voltage signal.

[0048] In one or some optional embodiments, the high-frequency signal generating circuit includes an active crystal oscillator;

[0049] The enable terminal of the active crystal oscillator is connected to the MCU control circuit;

[0050] The oscillation frequency of the active crystal oscillator is equal to the frequency of the surface acoustic wave chip.

[0051] In one or some optional embodiments, the signal processing circuit includes a gate driver, a first resistor and a second resistor;

[0052] The gate driver is connected to the first resistor and the second resistor respectively, and the output ends of the first resistor and the second resistor are connected in parallel;

[0053] The enable terminal of the gate driver is connected to the output terminal of the MCU control circuit.

[0054] As a third aspect of the embodiment of the present disclosure, it relates to a surface acoustic wave chip driving source circuit system, including: a charging circuit, a DC power supply circuit, an MCU control circuit, a human-computer interaction circuit and the surface acoustic wave chip driving circuit mentioned above;

[0055] The MCU control circuit is electrically connected to the charging circuit, the DC power supply circuit, the surface acoustic wave chip driving circuit, and the human-computer interaction circuit respectively;

[0056] The charging circuit is connected to the DC power supply circuit;

[0057] The output end of the DC power supply circuit is connected to the surface acoustic wave chip drive circuit, the MCU control circuit and the power supply end of the human-computer interaction circuit respectively;

[0058] The human-computer interaction circuit is used to send a control signal to the MCU control circuit and receive an indication signal returned by the MCU control circuit;

[0059] The MCU control circuit is used to control the operation of the surface acoustic wave chip driving circuit according to the control signal received from the human-machine interaction circuit, and send an indication signal to the human-machine interaction circuit.

[0060] In one or some optional embodiments, the charging circuit includes a charging interface, a boost circuit module, a charging control module, a battery and a voltage collection terminal;

[0061] The charging interface is connected to the boost circuit module, and the boost circuit module is connected to the battery;

[0062] The charging control module is connected to the boost circuit module and the battery respectively, and is used to control the magnitude of the output voltage and current of the boost circuit module and to stop the boost circuit module from working and output information that the battery is fully charged after the battery is fully charged;

[0063] The voltage acquisition end is connected to the voltage output end of the battery and the MCU control circuit;

[0064] The MCU control circuit is used to monitor the battery power information in real time through the voltage signal collected by the voltage collection terminal.

[0065] The embodiments of the present disclosure achieve at least the following technical effects:

[0066] The impedance matching circuit provided in the embodiment of the present invention is arranged between the signal source circuit and the surface acoustic wave chip load, so as to realize good signal and energy transmission between the signal source circuit and the surface acoustic wave chip load, reduce the interference of the reflected wave at the surface acoustic wave chip load end on the incident wave of the signal source circuit, so as to avoid oscillation of the signal source circuit, and effectively ensure the stable operation of the signal source circuit.

[0067] The impedance matching circuit provided in the embodiment of the present invention utilizes the changing relationship between temperature and the impedance of the surface acoustic wave chip, measures the temperature data of the surface acoustic wave chip load through a temperature measurement circuit, and obtains the impedance of the surface acoustic wave chip in real time by matching. It does not need to set up a complex detection circuit and a signal processing circuit, and can effectively simplify the complex structure of the impedance matching circuit and reduce the manufacturing cost.

[0068] The impedance matching circuit provided by the embodiment of the present invention sets a plurality of inductors and capacitors in the impedance matching network and sets control switches accordingly. The MCU controller can realize fast impedance matching according to the actual impedance matching requirements, and the impedance matching has strong operability. The impedance matching between the signal source circuit and the surface acoustic wave chip load is ensured by the impedance matching circuit, thereby maximizing the power transmission and realizing reflection-free power transmission, so that the signal energy can be efficiently transmitted to the surface acoustic wave chip load, and the reflection of the signal can be reduced, and the loss of the signal during the transmission process can be reduced, and the vicious cycle of further heating caused by mismatch due to parameter changes can be minimized, thereby improving the transmission efficiency of the signal, effectively ensuring the stable operation of the signal source circuit, and improving the surface acoustic wave chip load driving capability of the signal source circuit.

[0069] The impedance matching circuit provided in the embodiment of the present invention achieves matching of the real-time changing surface acoustic wave chip load with the signal source circuit through the impedance matching circuit, thereby ensuring that the energy of the signal source circuit is well absorbed by the surface acoustic wave chip load during the surface acoustic wave chip load driving process, reducing the rapid temperature rise of the signal source circuit due to energy reflection, reducing the additional heat dissipation cost of the signal source circuit, and improving the chip life in the signal source circuit and the system operation stability.

[0070] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. The purpose and other advantages of the present disclosure can be realized and obtained by the structures described in the written description, claims, and drawings.

[0071] The technical solution of the present disclosure is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0073] Figure 1 A schematic diagram of the structure of an impedance matching circuit provided in an embodiment of the present disclosure;

[0074] Figure 2 for Figure 1 A schematic diagram of the structure of an impedance matching network in the impedance matching circuit shown;

[0075] Figure 3 A graph showing the relationship between the real part of an acoustic surface wave load impedance and temperature provided in an embodiment of the present disclosure;

[0076] Figure 4 A graph showing the relationship between the imaginary part of an acoustic surface wave load impedance and temperature provided in an embodiment of the present disclosure;

[0077] Figure 5 for Figure 1 A schematic diagram of the structure of the temperature measurement circuit in the impedance matching circuit shown;

[0078] Figure 6 A schematic diagram of the structure of a signal source circuit provided by an embodiment of the present disclosure;

[0079] Figure 7 A schematic diagram of the structure of another signal source circuit provided by an embodiment of the present disclosure;

[0080] Figure 8 A schematic diagram of the structure of a driving source circuit system provided by an embodiment of the present disclosure;

[0081] Fig. 9 A schematic diagram of a charging circuit provided in an embodiment of the present disclosure;

[0082] Fig.10 A schematic diagram of the structure of a buck power supply circuit provided in an embodiment of the present disclosure;

[0083] Fig.11 A schematic diagram of the structure of another buck power supply circuit provided in an embodiment of the present disclosure;

[0084] Fig.12 A schematic diagram of a boost power supply circuit provided in an embodiment of the present disclosure;

[0085] Fig.13 A schematic diagram of the structure of an MCU control circuit provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0086] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The described implementation modes are part of the implementation modes of the present application, rather than all the implementation modes. The implementation modes described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the implementation modes in the present application, all other implementation modes obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0087] The embodiments of the present application are described in detail below in conjunction with the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0088] The inventors have discovered that if the signal source circuit is directly connected to the surface acoustic wave chip, there will be a large degree of impedance mismatch, resulting in a large power reflection, so that the energy output by the power source cannot be fully absorbed by the load, greatly reducing its energy transmission efficiency. In order to ensure that the surface acoustic wave chip maintains its driving capability, it is necessary to further increase the output power of the signal source circuit, which brings great burden and challenges to the signal source circuit. As the output power of the signal source circuit increases, the heat loss becomes more and more serious. Affected by temperature, the performance of the signal source circuit decreases rapidly, causing the output alternating voltage signal to decay rapidly, thereby affecting the load driving capability of the signal source circuit and reducing the driving capability of the surface acoustic wave chip. To this end, the inventors have made the present invention after further research and development, proposing an impedance matching circuit, related circuits and circuit systems.

[0089] Embodiment 1

[0090] The embodiment of the present invention provides an impedance matching circuit 10, which is connected between a signal source circuit 30 and a surface acoustic wave chip 20. Figure 1 and Figure 2 As shown, the impedance matching circuit 10 includes an MCU controller 101, a temperature measurement circuit 102, and an impedance matching network 103;

[0091] The impedance matching network 103 includes a matching inductor combination (not shown in the figure) and a matching capacitor combination (not shown in the figure), wherein the matching inductor combination includes a plurality of matching inductors of different inductances connected in series, and an inductor switch connected in parallel to each matching inductor; the matching inductor combination includes a plurality of matching capacitors of different capacitances connected in parallel, and a capacitor switch connected in series to each matching capacitor;

[0092] The temperature measurement circuit 102 is connected to the MCU controller 101 and is used to measure the temperature data of the surface acoustic wave chip 20 in real time and send the temperature data to the MCU controller 101;

[0093] The MCU controller 101 is connected to each of the inductance switches and each of the capacitance switches respectively, and is used to output a control signal according to the received temperature data to control the corresponding inductance switches and capacitance switches to be opened or closed.

[0094] The impedance matching circuit 10 provided in the embodiment of the present invention is arranged between the signal source circuit and the surface acoustic wave chip 30 to achieve good signal and energy transmission between the signal source circuit 30 and the surface acoustic wave chip 20, reduce the interference of the reflected wave at the load end of the surface acoustic wave chip 20 on the incident wave of the signal source circuit 30, so as to avoid oscillation of the signal source circuit 30, and effectively ensure the stable operation of the signal source circuit 30.

[0095] The impedance matching circuit 10 provided in the embodiment of the present invention utilizes the changing relationship between temperature and the impedance of the surface acoustic wave chip 20, measures the temperature data of the surface acoustic wave chip 20 through a temperature measuring circuit, and obtains the impedance of the surface acoustic wave chip 20 through real-time matching. It does not need to set up a complex detection circuit and a signal processing circuit, which can effectively simplify the complex structure of the impedance matching circuit 10 and reduce the manufacturing cost.

[0096] The impedance matching circuit 10 provided in the embodiment of the present invention sets a plurality of inductors and capacitors in the impedance matching network and sets corresponding control switches. The MCU controller can realize fast impedance matching according to the actual impedance matching requirements, and the impedance matching has strong operability. The impedance matching between the signal source circuit and the surface acoustic wave chip 20 is ensured by the impedance matching circuit 10, thereby maximizing the power transmission and realizing reflection-free power transmission, so that the signal energy can be efficiently transmitted to the surface acoustic wave chip 20, which can reduce the reflection of the signal and reduce the loss of the signal during the transmission process, and minimize the vicious cycle of further heating caused by mismatch caused by parameter changes, thereby improving the transmission efficiency of the signal, effectively ensuring the stable operation of the signal source circuit 30, and improving the surface acoustic wave chip load driving capability of the signal source circuit 30.

[0097] The impedance matching circuit 10 provided in the embodiment of the present invention achieves matching of the real-time changing surface acoustic wave chip 20 with the signal source circuit 30 through the impedance matching circuit 10, thereby ensuring that the energy of the signal source circuit is well absorbed by the surface acoustic wave chip load during the driving process of the surface acoustic wave chip 20, reducing the rapid temperature rise of the signal source circuit 30 due to energy reflection, reducing the additional heat dissipation cost of the signal source circuit 30, and improving the chip life and system operation stability in the signal source circuit 30.

[0098] In a specific embodiment, the corresponding relationship between the temperature and the impedance of the piezoelectric surface acoustic wave chip 20 can be pre-established in the MCU controller 101 to obtain a temperature and impedance matching relationship table. The MCU controller 101 is specifically used to determine the real-time impedance of the surface acoustic wave chip 20 based on the received temperature data and the pre-configured temperature and impedance matching relationship table, and calculate the inductance and capacitance of the impedance to be matched based on the impedance of the signal source circuit 30 and the real-time impedance of the surface acoustic wave chip 20 based on the following impedance calculation formula:

[0099]

[0100] in,

[0101]

[0102] Z M =Z I +XL *i, formula 5;

[0103] The impedance of the signal source circuit is Z I =R I +X I *i, where R I is the real part of the signal source impedance, X I is the imaginary part of the signal impedance;

[0104] The real-time impedance of the surface acoustic wave chip 20 is Z O =R O +X O *i, where R O is the real part of the impedance of the SAW chip 20, X O is the imaginary part of the impedance of the surface acoustic wave chip 20;

[0105] L is the inductance of the impedance to be matched, C is the capacitance of the impedance to be matched, and f is the operating frequency of the surface acoustic wave chip 20;

[0106] At least one matching capacitor and matching inductor that need to be connected is determined according to the inductance and capacitance of the impedance to be matched, and the control signal is determined and output according to the at least one matching capacitor and matching inductor that need to be connected.

[0107] In the embodiment of the present invention, the impedance of the signal source circuit 30 is measured to be Z I =R I +X I *i, where R I is the real part of the signal source impedance, X I is the imaginary part of the signal impedance. The real-time impedance of the surface acoustic wave chip 20 is calculated to be Z O =R O +X O *i, where R O is the real part of the impedance of the SAW chip 20, X O is the imaginary part of the impedance of the surface acoustic wave chip 20. Then, impedance matching is performed between the signal source circuit 30 and the surface acoustic wave chip 20, and the inductive reactance X required to be connected in series is calculated according to Formula 2. L Based on Formula 1, the inductance value of the inductor L that needs to be connected in series can be calculated, and then the impedance Z of the signal source circuit 30 after the inductor L is connected in series can be calculated by Formula 5. M , and then calculate the capacitive reactance X of the capacitor C that needs to be connected in parallel based on formula 4 C , and finally the capacitance of the parallel capacitor C is obtained.

[0108] In the embodiment of the present invention, the impedance Z of the signal source circuit 30 is I It can be calculated using conventional impedance calculation methods.

[0109] Exemplarily, the pre-configured temperature and impedance matching relationship table can be obtained in the following manner: before impedance matching is performed, the impedance change diagram of the surface acoustic wave chip 20 from the initial temperature to the maximum operating temperature is measured, such as Figure 3 and Figure 4 The figure shows the impedance variation of the surface acoustic wave chip 20 from room temperature to the maximum operating temperature of 160°. As can be seen from the figure, as the operating temperature of the surface acoustic wave chip 20 increases, its impedance is constantly changing, and each temperature corresponds to an impedance value. Therefore, a table representing the corresponding relationship between the temperature and the impedance of the piezoelectric surface acoustic wave chip 20, i.e., a matching relationship table of temperature and impedance, can be established, and the matching relationship table representing the corresponding relationship between temperature and impedance is stored in the MCU controller 101. During the operation of the surface acoustic wave chip 20, it is only necessary to measure the temperature data of the surface acoustic wave chip 20 in real time through the temperature measurement circuit 102. The temperature data is transmitted to the MCU controller 101, and the real-time impedance of the surface acoustic wave chip 20 at the current temperature can be obtained according to the stored matching relationship table of temperature and impedance.

[0110] In a specific embodiment, referring to Figure 2 As shown, the impedance matching network 103 includes a matching inductor combination including inductor L1031, inductor L1032, inductor L1033 and inductor L1034, a matching capacitor combination including capacitor C1031, capacitor C1032, capacitor C1033 and capacitor C1034, four inductor switches including switch S1, switch S2, switch S3 and switch S4, and four capacitor switches including switch S5, switch S6, switch S7 and switch S8.

[0111] One end of the inductor L1031 connected in parallel with the switch S1 is connected to the resonant capacitor C2, and the other end is connected to one end of the inductor L1032 connected in parallel with the switch S2, the other end of the inductor L1032 connected in parallel with the switch S2 is connected to one end of the inductor L1033 connected in parallel with the switch S3, the other end of the inductor L1033 connected in parallel with the switch S3 is connected to one end of the inductor L1034 connected in parallel with the switch S4, the other end of the inductor L4 connected in parallel with the switch S4 is connected to the surface acoustic wave chip 20 and one end of the switch S5, the switch S6, the switch S7, and the switch S8 in parallel, the switch S5 is connected to one end of the capacitor C1031, the switch S6 is connected to one end of the capacitor C1032, the switch S7 is connected to one end of the capacitor C1033, the switch S8 is connected to one end of the capacitor C1034, and the other ends of the capacitors C1031, C1032, C1033, and C1034 are connected in parallel and then grounded.

[0112] When the switches S1, S2, S3 and S4 connected in parallel with the inductor L1031, L1032, L1033 and L1034 are closed, the corresponding inductors fail; when the switches S1, S2, S3 and S4 connected in parallel with the inductor L1031, L1032, L1033 and L1034 are disconnected, the corresponding inductors are valid; when the switches S5, S6, S7 and S8 connected in series with the capacitor C1031, C1032, C1033 and C1034 are closed, the corresponding capacitors are valid; when the switches S5, S6, S7 and S8 connected in series with the capacitor C1031, C1032, C1033 and C1034 are disconnected, the corresponding capacitors fail.

[0113] The MCU controller 101 can control the open and closed states of all switches S1 to S8. By controlling the MCU controller 101 to control different combinations of closing and opening of the four switches connected in parallel with the inductor, different values ​​of the inductor connected to the impedance matching circuit 10 can be obtained. Similarly, by controlling the MCU controller 101 to control different combinations of closing and opening of the four switches connected in series with the capacitor, different values ​​of the capacitor connected to the impedance matching circuit 10 can be obtained. Then, different impedance values ​​can be matched by combinations of different inductance values ​​and capacitance values. Therefore, after calculating the inductance and capacitance of the impedance to be matched, the MCU controller can determine the inductance value combination that is equal to or closest to the inductance of the impedance to be matched, and determine the capacitance value combination that is equal to or closest to the capacitance of the impedance to be matched, determine at least one matching capacitor and matching inductor that need to be connected, determine the open and closed states of all switches S1 to S8 according to the at least one matching capacitor and matching inductor that need to be connected, and output a control signal for controlling the open and closed of all switches S1 to S8.

[0114] For example, based on the pre-configured temperature and impedance matching relationship table, the maximum impedance Z of the surface acoustic wave chip 20 can be determined. M , assuming that the impedance of the signal source circuit 30 is Z I If the impedance is unchanged, then according to the above formulas 1 to 5, the maximum inductance value L required for series impedance matching can be calculated. M And the maximum capacitance C that needs to be connected in parallel M . You can set Figure 2 The values ​​of the inductance L1031, the inductance L1032, the inductance L1033 and the inductance L1034 are as follows: set up Figure 2 The values ​​of the capacitor C1031, the capacitor C1032, the capacitor C1033 and the capacitor C1034 are as follows:

[0116] By controlling the MCU controller 101 to open and close the switches S1, S2, S3, and S4, the inductance value of the series inductor L actually connected to the impedance matching circuit 10 can be obtained (1 indicates that the switch is closed, and 0 indicates that the switch is open), that is:

[0117] S1=1, S2=0, S3=0, S4=0:

[0118] S1=0, S2=1, S3=0, S4=0:

[0119] S1=0, S2=0, S3=1, S4=0:

[0120] S1=0, S2=0, S3=0, S4=1:

[0121] S1=1, S2=0, S3=0, S4=1:

[0122] S1=0, S2=1, S3=0, S4=1:

[0123] S1=0, S2=0, S3=1, S4=1:

[0124] S1=1, S2=0, S3=1, S4=1:

[0125] S1=0, S2=1, S3=1, S4=1:

[0126] S1=1, S2=1, S3=1, S4=1:L=1L M ;

[0127] All the above switch combinations and the corresponding values ​​of the inductance L are stored in the MCU controller 101, and the corresponding value of the series inductance L can be selected by selecting the corresponding switch combination.

[0128] Similarly, by controlling the MCU controller 101 to open and close the switches S5, S6, S7, and S8, the capacitance of the parallel capacitor C actually connected to the impedance matching circuit 10 can be obtained (1 indicates that the switch is closed, and 0 indicates that the switch is open), that is:

[0129] S5=1, S6=0, S7=0, S8=0:

[0130] S5=0, S6=1, S7=0, S8=0:

[0131] S5=0, S6=0, S7=1, S8=0:

[0132] S5=0, S6=0, S7=0, S8=1:

[0133] S5=1, S6=0, S7=0, S8=1:

[0134] S5=0, S6=1, S7=0, S8=1:

[0135] S5=0, S6=0, S7=1, S8=1:

[0136] S5=1, S6=0, S7=1, S8=1:

[0137] S5=0, S6=1, S7=1, S8=1:

[0138] S5=1, S6=1, S7=1, S8=1:C=1C M ;

[0139] All the above switch combinations and the corresponding values ​​of the capacitor C are stored in the MCU controller 101, and the corresponding capacitance value of the parallel capacitor C can be selected by selecting the corresponding switch combination.

[0140] During the operation of the surface acoustic wave chip 20, the temperature data of the surface acoustic wave chip 20 is measured in real time by the temperature measuring circuit 102, and the MCU controller 101 obtains the real-time impedance of the surface acoustic wave chip 20 under the current temperature data according to the above matching relationship table. Then, the inductance value of the required series inductor and the capacitance value of the required parallel capacitor under the current impedance are calculated according to Formulas 1 to 5. Thus, it is determined that the inductance value of the required series inductor is closest to the inductance value of the series inductor L under which of the above switch combinations, and it is determined that the capacitance value of the required parallel capacitor is closest to the capacitance value of the parallel capacitor C under which of the above switch combinations, and then the corresponding control signals for controlling the switches S1 to S8 to be closed or opened are output.

[0141] Of course, the impedance matching network in the embodiment of the present invention may also adopt other types of matching networks in the prior art, and the number of inductors, capacitors, and switches in the matching network may also adopt other numbers. In this regard, no specific limitation is made in the embodiment of the present invention.

[0142] In a specific embodiment, referring to Figure 5As shown, the temperature measurement circuit 102 includes a DC power supply VCC, a thermistor R es , current limiting resistor R x , compensation resistor R b and measurement circuit ADC;

[0143] The DC power supply VCC, the current limiting resistor R x and thermistor R es Connect in sequence;

[0144] The compensation resistor R b With the thermistor R es Connect in parallel and ground;

[0145] The measuring circuit ADC is connected to the current limiting resistor R x With the thermistor R es It is used to measure the voltage signal in real time, convert the voltage signal into temperature data of the surface acoustic wave chip 20, and send it to the MCU controller 101.

[0146] In the embodiment of the present invention, the thermistor R es Can be NTC thermistor, current limiting resistor R x With thermistor R es When the SAW chip 20 is working, the resistance of the thermistor changes with the temperature of the SAW chip 20. By measuring the output voltage of the voltage divider circuit through the measuring circuit ADC, a voltage signal proportional to the resistance of the thermistor can be obtained. es Since the resistance of the thermistor has a linear relationship with the temperature, the temperature of the SAW chip 20 can be inferred, and the compensation resistor R b It can compensate for the nonlinearity of the NTC resistor and can convert the thermistor R es The relationship between resistance and temperature becomes linear, thereby improving the accuracy of the measured temperature data.

[0147] In the embodiment of the present invention, the MCU controller 101 can be implemented by a single chip microcomputer in the prior art, and those skilled in the art can make a choice according to actual needs. The chip and circuit settings of the MCU controller are not specifically limited here.

[0148] Embodiment 2

[0149] The embodiment of the present invention provides a surface acoustic wave chip driving circuit 3, referring to Figure 1 and Figure 2 As shown, it includes: a signal source circuit 30 and the impedance matching circuit 10 described in the first embodiment;

[0150] Reference Figure 6 and Figure 7 , the signal source circuit 30 includes a high-frequency signal generating circuit 31, a signal processing circuit 32 and a power amplifier matching circuit 33 connected in sequence;

[0151] The high-frequency signal generating circuit 31 is used to output a high-frequency square wave signal;

[0152] The signal processing circuit 32 is used to process the high-frequency square wave signal to obtain a processed high-frequency square wave signal;

[0153] The power amplifier matching circuit 33 is used to amplify the power of the processed high-frequency square wave signal to obtain a power-amplified high-frequency square wave signal, and filter the power-amplified high-frequency square wave signal to obtain a high-frequency AC signal.

[0154] In the embodiment of the present invention, the square wave signal generated by the high-frequency signal generating circuit 31 is processed by the signal processing circuit 32 to increase the voltage and current of the high-frequency square wave signal, realize the stable conduction and shutdown of the switch tube circuit, and reduce the switching loss. The power amplifier matching circuit 33 is used to amplify and filter the signal to obtain the high-frequency AC signal required by the surface acoustic wave chip 20 load. Compared with the driving source system excited by the high-frequency AC sinusoidal signal synthesized by push-pull resonance and other methods in the prior art, the driving source circuit system has a simpler topological structure, higher conversion efficiency, low power consumption, and low board temperature. Correspondingly, the circuit device is smaller in size, more compact in structure, and the overall size of the circuit board is effectively reduced, with higher reliability, which is convenient for realizing stable and efficient output of high-frequency AC signals to drive the surface acoustic wave chip 20 load, and can be applied to more application scenarios requiring miniaturization and portable driving.

[0155] In one embodiment, referring to Figure 7 , the power amplifier matching circuit 33 includes a MOS tube Q1, a choke inductor L1, a parallel capacitor C1, a resonant inductor L2 and a resonant capacitor C2; wherein:

[0156] The gate of the MOS transistor Q1 is connected to the output end of the signal processing circuit 32, the drain of the MOS transistor Q1 is respectively connected to the choke inductor L1, the parallel capacitor C1 and the resonant inductor L2, the source of the MOS transistor Q1 is grounded, the other end of the choke inductor L1 is connected to the input voltage, the other end of the parallel capacitor C1 is grounded, and the other end of the resonant inductor L2 is connected to the resonant capacitor C2, and the resonant capacitor C2 is used to output the high-frequency AC signal;

[0157] The duty cycle of the high-frequency square wave signal input to the gate of the MOS transistor Q1 is 0.5.

[0158] In the embodiment of the present invention, the MOS transistor Q1 can be an NMOS transistor, the MOS transistor Q1 works in a switching mode, and the duty cycle of the high-frequency square wave signal input to the gate is 0.5, the processed high-frequency square wave signal output by the signal processing circuit 32 is input to the gate of the MOS transistor Q1, thereby driving the MOS transistor Q1 to perform rapid on and off switching, and the MOS transistor quickly switches on and off to achieve the function of amplifying the input high-frequency square wave signal power. The resonant inductor L2 and the resonant capacitor C2 are used to form an LC series resonant circuit, so that the circuit works in a resonant state, and the amplified high-frequency square wave signal is filtered through the LC series resonant circuit, and the harmonic signal in the high-frequency square wave signal is filtered out to leave the fundamental signal, that is, the high-frequency AC signal.

[0159] In a specific embodiment, the parallel capacitor C1 includes the parasitic capacitance of the MOS transistor Q1. In order to further reduce the power loss of the MOS transistor Q1 and improve the overall conversion efficiency of the circuit, it is known that the duty cycle of the high-frequency square wave signal input to the gate of the MOS transistor Q1 is 0.5, the frequency f of the high-frequency AC voltage signal (i.e., the operating frequency f of the surface acoustic wave chip), and the given DC input voltage V dc , output power P o And the quality factor Q of the LC series resonant circuit L Under the condition of, the minimum value of the choke inductor L1, the value of the parallel capacitor C1, the value of the resonant inductor L2 and the value of the resonant capacitor C2 can be calculated by the following equations 6 to 9. Specifically:

[0160] The minimum value of the choke inductor L1 is calculated by the following formula 6:

[0161]

[0162] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, L1 represents the minimum value of the choke inductance L1, and f represents the frequency of the high-frequency AC voltage signal;

[0163] The value of the parallel capacitor C1 is calculated by the following formula 7:

[0164]

[0165] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, C1 represents the value of the parallel capacitor C1, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, f represents the frequency of the high-frequency AC voltage signal;

[0166] The value of the resonant inductor L2 is calculated by the following formula 8:

[0167]

[0168] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, L2 represents the value of the resonant inductor L2, Q L represents the quality factor of the LC series resonant circuit, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, f represents the frequency of the high-frequency AC voltage signal;

[0169] The value of the resonant capacitor C2 is calculated by the following formula 9:

[0170]

[0171] in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, C2 represents the value of the resonant capacitor C2, L2 represents the value of the resonant inductor L2, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, and f represents the frequency of the high-frequency AC voltage signal.

[0172] In the embodiment of the present invention, when the above-mentioned signal source circuit 30 is used, the impedance Z of the signal source circuit is I It can be calculated as follows:

[0173]

[0174] in, V dc Indicates DC input voltage, P o Indicates the output power.

[0175] In the embodiment of the present invention, the resonant capacitor C2 of the signal source circuit is connected in series with a plurality of matching inductors in the impedance matching circuit 10, and is used to connect the surface acoustic wave chip 20, and output a high-frequency AC voltage signal to the surface acoustic wave chip 20; the plurality of matching capacitors of the impedance matching circuit 10 are connected in parallel with the surface acoustic wave chip 20. The impedance matching between the signal source circuit and the surface acoustic wave chip 20 is ensured by the impedance matching circuit 10, so as to maximize the transmission of power, realize non-reflection power transmission, enable the signal energy to be efficiently transmitted to the load, reduce the reflection of the signal, and reduce the loss of the signal during the transmission process, thereby improving the transmission efficiency of the signal and effectively ensuring the working stability of the signal source circuit.

[0176] In an alternative embodiment, referring to Figure 7As shown, the high-frequency signal generating circuit 31 includes an active crystal oscillator Y1;

[0177] The enable terminal EN of the active crystal oscillator Y1 is connected to the MCU control circuit 4;

[0178] The oscillation frequency of the active crystal oscillator Y1 is equal to the frequency of the surface acoustic wave chip 20 .

[0179] When the MCU control circuit 4 outputs an enable signal, the high-frequency signal generating circuit 31 outputs a high-frequency square wave signal.

[0180] In the surface acoustic wave chip driving circuit provided in the embodiment of the present invention, the oscillation frequency of the active crystal oscillator Y1 can be determined according to the frequency of the surface acoustic wave chip 20, so that the frequency of the high-frequency AC voltage signal finally output is consistent with the frequency of the surface acoustic wave chip 20, so that the high-frequency signal generating circuit outputs a radio frequency signal that best matches the load of the surface acoustic wave chip 20, so that the load of the surface acoustic wave chip 20 always works in the optimal resonant state, effectively reducing energy loss, and at the same time ensuring that the surface acoustic wave chip 20 outputs a large amplitude and strong driving capability.

[0181] In an alternative embodiment, referring to Figure 7 As shown, the signal processing circuit 32 includes a gate driver U1, a first resistor R1 and a second resistor R2;

[0182] The gate driver U1 is connected to the first resistor R1 and the second resistor R2 respectively, and the output ends of the first resistor R1 and the second resistor R2 are connected in parallel;

[0183] The enable terminal ON of the gate driver U1 is connected to the output terminal of the MCU control circuit 4. When the MCU control circuit 4 outputs an enable signal, the high-frequency square wave signal input by the high-frequency signal generating circuit 31 is processed and then output as a high-frequency square wave signal having the gate driving capability of the MOS tube Q1.

[0184] In the embodiment of the present invention, the gate driver U1 may adopt an isolated gate driver, such as LM5114BMF / NOPB type isolated gate driver. Of course, the gate driver U1 in the embodiment of the present invention may also adopt other isolated gate drivers in the prior art, which is not specifically limited in the embodiment of the present invention.

[0185] Embodiment 3

[0186] The embodiment of the present invention provides a surface acoustic wave chip driving source circuit system, referring to Figure 8 As shown, it includes: a charging circuit 1, a DC power supply circuit 2, an MCU control circuit 4, a human-computer interaction circuit 5 and the surface acoustic wave chip driving circuit 3 described in the second embodiment;

[0187] The MCU control circuit 4 is electrically connected to the charging circuit 1, the DC power supply circuit 2, the surface acoustic wave chip driving circuit 3, and the human-computer interaction circuit 5 respectively;

[0188] The charging circuit 1 is connected to the DC power supply circuit 2 and is used to provide an input voltage signal to the DC power supply circuit 2;

[0189] The output end of the DC power supply circuit 2 is respectively connected to the power supply end of the surface acoustic wave chip driving circuit 3, the MCU control circuit 4 and the human-computer interaction circuit 5, and is used to perform voltage step-up or voltage step-down processing on the voltage signal provided by the charging circuit 1 and then output the DC voltage signal required by the MCU control circuit 4, the human-computer interaction circuit 5, the high-frequency signal generating circuit 31, the signal processing circuit 32 and the power amplifier matching circuit 33;

[0190] The human-computer interaction circuit 5 is used to send a control signal to the MCU control circuit 4 and receive an indication signal returned by the MCU control circuit 4, so as to provide a corresponding indication judgment for the user;

[0191] The MCU control circuit 4 is used to control the operation of the surface acoustic wave chip driving circuit 3 according to the control signal received from the human-machine interaction circuit 5 , and send an indication signal to the human-machine interaction circuit 5 .

[0192] Specifically, the MCU control circuit 4 may be electrically connected to the charging circuit 1, the DC power supply circuit 2, the high-frequency signal generating circuit 31, the signal processing circuit 32, and the human-computer interaction circuit 5 respectively;

[0193] The output end of the DC power supply circuit 2 is respectively connected to the power supply end of the high-frequency signal generating circuit 31, the signal processing circuit 32, the power amplifier matching circuit 33, the MCU control circuit 4 and the human-computer interaction circuit 5, and is used to perform voltage step-up or voltage step-down processing on the voltage signal provided by the charging circuit 1 and then output the DC voltage signal required by the MCU control circuit 4, the human-computer interaction circuit 5, the high-frequency signal generating circuit 31, the signal processing circuit 32 and the power amplifier matching circuit 33;

[0194] The MCU control circuit 4 is used to control the operation of the high-frequency signal generating circuit 31 and the signal processing circuit 32 according to the control signal received from the human-machine interaction circuit 5 , and send an instruction signal to the human-machine interaction circuit 5 .

[0195] In one embodiment, referring to Fig. 9 As shown, the charging circuit 1 includes a charging interface 11, a boost circuit module 12, a charging control module 13, a battery 14 and a voltage collection terminal AD0;

[0196] The charging interface 11 is connected to the boost circuit module 12, and the boost circuit module 12 is connected to the battery;

[0197] The charging control module 13 is connected to the boost circuit module 12 and the battery 14 respectively, and is used to control the magnitude of the output voltage and current of the boost circuit module 12 and to stop the boost circuit module from working and output information that the battery is fully charged after the battery 14 is fully charged;

[0198] The voltage acquisition terminal AD0 is connected to the voltage output terminal BAT+ of the battery and the MCU control circuit 4;

[0199] The MCU control circuit is used to monitor the battery power information in real time through the voltage signal collected by the voltage collection terminal AD0.

[0200] In a specific embodiment, the charging interface 11 is used to input a charging voltage signal to the system, and the input voltage of the charging interface 11 may be 5V. The boost circuit module 12 is used to convert the voltage signal input from the charging interface 11 to a suitable charging voltage. The charging control module 13 is used to control the magnitude of the output voltage and current of the boost circuit module 12 during the entire charging process, and to stop the boost circuit module from working and output information that the battery is fully charged after the battery 14 is fully charged.

[0201] In a specific embodiment, the battery may be a fully charged 12.6V battery, which is used to provide power for the entire surface acoustic wave chip driving source circuit system. The voltage acquisition terminal AD0 is connected between the third resistor R3 and the fourth resistor R4, and is connected to the analog signal acquisition port of the MCU control circuit 4. The MCU control circuit monitors the battery power information in real time by real-time acquisition of the voltage signal of the voltage acquisition terminal AD0.

[0202] In an optional embodiment, the battery 14 can also be 1.5V, 3.7V, 8.4V, 24V, etc., without specific limitation. Different boost circuit modules are selected accordingly according to the voltage value of the battery 14 to convert the voltage input by the charging interface 11 to the charging voltage required by the battery 14.

[0203] In a specific embodiment, the charging control module 13 controls the battery charging to be divided into three stages, namely, a pre-charging stage, a constant current stage, and a constant voltage stage. The specific working process of the charging circuit 1 specifically includes:

[0204] When the charging interface 11 is connected to a 5V DC power supply, the boost circuit module 12 boosts the 5V power supply voltage to the current battery power supply voltage;

[0205] If the battery voltage is lower than 9V, the charging control module 13 controls the boost circuit module 12 to enter the pre-charging stage, for example, to pre-charge the battery with a current of 200mA;

[0206] If the battery voltage reaches 9V, the charging control module 13 controls the boost circuit module 12 to enter the constant current stage to charge the battery with a constant current, for example, the charging current is constant at 0.8A;

[0207] If the battery voltage reaches 12.6V, the charging control module 13 controls the boost circuit module 12 to enter the constant voltage stage. At this time, the output voltage of the charging circuit 1 changes in real time with the battery voltage. When the battery voltage reaches 12.6V, the battery is fully charged and the charging process is terminated. If the battery voltage is consumed and drops below 12.3V, the charging control module 13 controls the boost circuit module 12 again to charge the battery.

[0208] In the embodiment of the present invention, the boost circuit module 12 and the charging control module 13 can be composed of an integrated chip HM4042_12.6 switch type lithium polymer battery charging management chip and its peripheral circuits. HM4042_12.6 is a chip for boosting and charging 5V input three-series lithium batteries, which has both boosting function and charging management function. Of course, the boost circuit module 12 and the charging control module in the embodiment of the present invention can also use other boost circuit chips and charging management chips in the prior art. In this regard, no specific limitation is made in the embodiment of the present invention.

[0209] In an optional embodiment, the DC power supply circuit 2 may include one or more buck power supply circuits and / or boost power supply circuits, the input end of each buck power supply circuit and / or boost power supply circuit is connected to the output end BAT+ of the charging circuit 1, and the output end is connected to at least one of the power supply ends of the high-frequency signal generating circuit 31, the signal processing circuit 32, the power amplifier matching circuit 33, the MCU control circuit 4 and the human-computer interaction circuit 5.

[0210] In a specific embodiment, the DC power supply circuit 2 may include two buck power supply circuits and one boost power supply circuit. The two buck power supply circuits each use an integrated buck chip TLV62130 to form a buck conversion DC / DC voltage stabilizing circuit, and the boost power supply circuit may use an integrated boost chip TPS61178 to form a boost conversion DC / DC voltage stabilizing circuit. For example, refer to Fig.10 As shown, a buck power supply circuit outputs a 3.3V voltage signal for providing power signals for the MCU control circuit 4 and the human-computer interaction circuit 5. Fig.11As shown, another buck power supply circuit outputs a 5V voltage signal for providing a power supply signal for the high-frequency signal generating circuit 31 and the signal processing circuit 32. Fig.12 As shown, the boost power supply circuit can adjust and output a voltage signal VCC_ADJ of 13V to 20V according to the power requirement of the driving source circuit system to drive the surface acoustic wave chip load, so as to provide input voltage for the power amplifier matching circuit 33 .

[0211] The surface acoustic wave chip driving source circuit system provided in the embodiment of the present invention can drive the power requirements of the surface acoustic wave chip load under different driving capabilities according to the driving source circuit system, adjust the size of the voltage signal input to the resistor R21, adjust the range of the output voltage signal of the DC power supply circuit, and further control the output power value of the power amplifier matching circuit 33 to meet the driving application of the surface acoustic wave chip in different scenarios, such as microfluid atomization, droplet injection, solution mixing, cell fusion and separation, particle arrangement and sorting.

[0212] The human-machine interaction circuit 5 only needs to be able to input a recognizable signal to the MCU control circuit and to prompt the user to start or stop the system and the battery level information. The corresponding circuit can be selected according to the usage scenario of the driving source circuit system.

[0213] In a specific embodiment, to facilitate understanding of the technical solution of the present invention, the human-computer interaction circuit 5 is composed of two common devices: a button and three indicator lights of different colors. The button is connected to the MCU microcontroller circuit 4 for inputting a control signal to the MCU control circuit 4. The three indicator lights of different colors are respectively connected to the MCU microcontroller circuit 4 for indicating whether the system is turned on or off and the battery level.

[0214] The user can send control information to the MCU control circuit by operating the length of time or number of times a button is pressed. When the MCU control circuit 4 receives the control information sent by the user by operating the button, the MCU control circuit 4 controls the system to start or stop working and controls the three indicator lights to make corresponding indications. If the system is in working state or the battery is in charging state, the MCU control circuit 4 can collect and feedback the battery power information in real time, and control the three indicators to make corresponding indications according to the power information, so that the user can monitor the current battery power and determine whether the battery needs to be charged.

[0215] In an optional embodiment, the MCU control circuit 4 can be implemented using a single-chip computer system, such as the N32L403KBQ7 chip. The MCU control circuit 4 is respectively connected to the battery power collection terminal AD0 in the charging circuit 1, the DC power supply circuit 2, the human-computer interaction circuit 5, and the enable terminal EN of the active crystal oscillator circuit in the high-frequency signal generating circuit 31, and the enable terminal ON of the gate driver U1 in the signal processing circuit 32. When the system is connected to the battery, the MCU control circuit 4 starts to be in working state to control the operation of the driving source circuit system. For example, assuming that the colors of the three indicator lights are red, green and blue, refer to Fig.13 As shown, it is a specific implementation of the MCU control circuit 4, wherein 6027 is a key interface, which matches the key of the human-machine interaction circuit 5, the 10-pin terminal of the MCU control chip is connected to the red indicator light of the human-machine interaction circuit 5, the 11-pin terminal of the MCU control chip is connected to the green indicator light of the human-machine interaction circuit 5, and the 12-pin terminal of the MCU control chip is connected to the blue indicator light of the human-machine interaction circuit 5. Exemplarily, in a specific implementation of the MCU control circuit 4, the 10-pin terminal of the MCU control chip can also output a voltage signal to the resistor R21 of the boost power supply circuit to adjust the size of the output voltage signal of the DC power supply circuit.

[0216] By programming the MCU control circuit 4, after the system is powered on for the first time, if there is no operation on the button within 2 seconds, the system will enter the low power consumption mode to reduce the loss of battery power. The system is set to press the button 5 times quickly and continuously within 2 seconds in the low power consumption mode, and the system is turned on and enters the standby state; in the system standby working state, it is set to press the button 5 times quickly and continuously within 2 seconds, and the system is shut down and enters the low power consumption mode. When the system is not turned on, if the user presses the button less than 5 times within 2s, the system will not turn on. After the system is turned on and enters the standby state, the MCU control circuit 4 will monitor the state of the button in real time. If it is detected that the user presses the button for a long time, the MCU control circuit 4, the high-frequency signal generating circuit 31, and the signal processing circuit 32 start working, and the system starts to output a high-frequency AC voltage signal to drive the load to be driven to work, and at the same time, the MCU control circuit 4 controls the indicator light to indicate the battery power information. If the user releases the button, the MCU control circuit 4 controls the high-frequency signal generating circuit 31 and the signal processing circuit 32 to stop working, and the system stops outputting the high-frequency AC voltage signal. When the system is in standby mode, if the MCU control circuit 4 does not receive any instruction from the user through a key for 40 consecutive seconds, the MCU control circuit 4 controls the system to enter a low power consumption mode.

[0217] By programming the MCU control circuit 4, when the system is turned on, the indicator light flashes three times in white; when the system is turned off, the indicator light flashes twice in white; when the system is in working state, long press the button and when the charging circuit 2 is working, the three-color indicator light displays the battery power status in real time. In a specific embodiment, when the system is in working state, when it is detected that the battery power is greater than 70%, the MCU control circuit 4 controls the green indicator light to be always on, when it is detected that the battery power is between 30% and 70%, the MCU control circuit 4 controls the blue indicator light to be always on, when it is detected that the battery power is less than 30%, the MCU control circuit 4 controls the red indicator light to be always on, when the charging circuit 4 is working, when it is detected that the battery power is greater than 70%, the MCU control circuit 2 controls the green indicator light to flash, when it is detected that the battery power is between 30% and 70%, the MCU control circuit 4 controls the blue indicator light to flash, when it is detected that the battery power is less than 30%, the MCU control circuit 4 controls the red indicator light to flash, when it is detected that the battery power is full, the MCU control circuit 4 controls all three-color indicators to light up and display in white for 10s and then turn off the display. When it is detected that the battery power is less than 10%, the MCU control circuit 4 first sends an instruction to control the red indicator light to flash three times, and then the control circuit 4 controls the system to enter the low power consumption mode.

[0218] In the embodiment of the present invention, the number of key presses and the key press time of the user and the indication of the indicator light can be set according to specific needs. In this regard, no specific limitation is made in the embodiment of the present invention.

[0219] Based on the same inventive concept, the embodiment of the present disclosure further provides a load driving system, including: a surface acoustic wave chip 20 and the above-mentioned surface acoustic wave chip driving source circuit system.

[0220] The specific implementation of the surface acoustic wave chip driving source circuit system in the load driving system provided by the embodiment of the present invention can refer to the detailed description in the above embodiment, which will not be repeated here.

[0221] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and examples are considered to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the claims. It should be understood that the present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An impedance matching circuit connected between a signal source circuit and a surface acoustic wave chip, characterized in that: The impedance matching circuit includes an MCU controller, a temperature measurement circuit and an impedance matching network; The impedance matching network includes a matching inductor combination and a matching capacitor combination, wherein the matching inductor combination includes a plurality of matching inductors of different inductances connected in series, and an inductor switch connected in parallel to each matching inductor; the matching inductor combination includes a plurality of matching capacitors of different capacitances connected in parallel, and a capacitor switch connected in series to each matching capacitor; The temperature measurement circuit is connected to the MCU controller, and is used to measure the temperature data of the surface acoustic wave chip in real time and send the data to the MCU controller; The MCU controller is connected to each of the inductance switches and each of the capacitance switches respectively, and is used to output a control signal according to the received temperature data to control the corresponding inductance switches and capacitance switches to be opened or closed.

2. The impedance matching circuit according to claim 1, wherein: The MCU controller is specifically used to determine the real-time impedance of the surface acoustic wave chip according to the received temperature data and based on a pre-configured temperature and impedance matching relationship table, and calculate the inductance and capacitance of the impedance to be matched based on the following impedance calculation formula according to the impedance of the signal source circuit and the real-time impedance of the surface acoustic wave chip: in, Z M = Z l + X L * i, Equation 5; The impedance of the signal source circuit is Z I =R I +X I *i, where R I is the real part of the signal source impedance, X I is the imaginary part of the signal impedance; The current impedance of the SAW chip is Z O =R O +X O *i, where R O is the real part of the impedance of the SAW chip, X O is the imaginary part of the impedance of the SAW chip; L is the inductance of the impedance to be matched, C is the capacitance of the impedance to be matched, and f is the operating frequency of the surface acoustic wave chip; At least one matching capacitor and matching inductor that need to be connected is determined according to the inductance and capacitance of the impedance to be matched, and the control signal is determined and output according to the at least one matching capacitor and matching inductor that need to be connected.

3. The impedance matching circuit according to claim 2, characterized in that: The matching inductor combination includes four matching inductors and four inductor switches; the matching inductor combination includes four matching capacitors and four capacitor switches; The values ​​of the four matching inductors are and The values ​​of the four matching capacitors are and Among them, L M and C M The value of is calculated based on the impedance calculation formula according to the impedance of the signal source circuit and the maximum impedance of the surface acoustic wave chip.

4. The impedance matching circuit according to any one of claims 1 to 3, characterized in that: The temperature measurement circuit includes a DC power supply, a thermistor, a current limiting resistor, a compensation resistor and a measurement circuit; The DC power supply, current limiting resistor and thermistor are connected in sequence; The compensation resistor is connected in parallel with the thermistor and is grounded; The measuring circuit is connected between the current limiting resistor and the thermistor, and is used for measuring the voltage signal in real time, converting the voltage signal into temperature data of the surface acoustic wave chip, and sending the data to the MCU controller.

5. A surface acoustic wave chip driving circuit, characterized in that: Comprising a signal source circuit and an impedance matching circuit according to any one of claims 1 to 4; The signal source circuit is connected to the impedance matching circuit and is used to provide a high-frequency AC signal.

6. The surface acoustic wave chip driving circuit according to claim 5, characterized in that: The signal source circuit comprises a high-frequency signal generating circuit, a signal processing circuit and a power amplifier matching circuit connected in sequence; The high-frequency signal generating circuit is used to output a high-frequency square wave signal; The signal processing circuit is used to process the high-frequency square wave signal to obtain a processed high-frequency square wave signal; The power amplifier matching circuit is used to amplify the power of the processed high-frequency square wave signal to obtain a power-amplified high-frequency square wave signal, and filter the power-amplified high-frequency square wave signal to obtain a high-frequency AC signal.

7. The surface acoustic wave chip driving circuit according to claim 6, characterized in that: The power amplifier matching circuit includes a MOS tube, a choke inductor, a parallel capacitor, a resonant inductor and a resonant capacitor; The gate of the MOS tube is connected to the output end of the signal processing circuit, the drain of the MOS tube is respectively connected to the choke inductor, the shunt capacitor and the resonant inductor, the source of the MOS tube is grounded, the other end of the choke inductor is connected to the input voltage, the other end of the shunt capacitor is grounded, the other end of the resonant inductor is connected to the resonant capacitor, and the other end of the resonant capacitor is used to output the high-frequency AC signal; The duty cycle of the processed high-frequency square wave signal input to the gate of the MOS tube is 0.

5.

8. The surface acoustic wave chip driving circuit according to claim 7, characterized in that: The minimum value of the choke inductor L1 is calculated by the following formula 6: in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, L1 represents the minimum value of the choke inductance L1, and f represents the frequency of the high-frequency AC voltage signal; The value of the parallel capacitor C1 is calculated by the following formula 7: in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, C1 represents the value of the parallel capacitor C1, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, f represents the frequency of the high-frequency AC voltage signal; The value of the resonant inductor L2 is calculated by the following formula 8: in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, L2 represents the value of the resonant inductor L2, Q L represents the quality factor of the LC series resonant circuit, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, f represents the frequency of the high-frequency AC voltage signal; The value of the resonant capacitor C2 is calculated by the following formula 9: in, V dc Indicates DC input voltage, P o represents the maximum value of the output power, C2 represents the value of the resonant capacitor C2, L2 represents the value of the resonant inductor L2, ω represents the angular frequency of the high-frequency AC voltage signal, ω=2πf, and f represents the frequency of the high-frequency AC voltage signal.

9. A surface acoustic wave chip driving source circuit system, characterized in that: include: A charging circuit, a DC power supply circuit, an MCU control circuit, a human-computer interaction circuit, and a surface acoustic wave chip driving circuit as described in any one of claims 5 to 8; The MCU control circuit is electrically connected to the charging circuit, the DC power supply circuit, the surface acoustic wave chip driving circuit, and the human-computer interaction circuit respectively; The charging circuit is connected to the DC power supply circuit; The output end of the DC power supply circuit is connected to the surface acoustic wave chip drive circuit, the MCU control circuit and the power supply end of the human-computer interaction circuit respectively; The human-computer interaction circuit is used to send a control signal to the MCU control circuit and receive an indication signal returned by the MCU control circuit; The MCU control circuit is used to control the operation of the surface acoustic wave chip driving circuit according to the control signal received from the human-machine interaction circuit, and send an indication signal to the human-machine interaction circuit.

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