Impedance spectrum measuring circuit of piezoelectric actuator, chip and electronic equipment

Abstract

The invention discloses an impedance spectrum measuring circuit and chip of a piezoelectric actuator and electronic equipment, and belongs to the technical field of electronic circuits, and a driving circuit outputs a driving signal according to a test control signal so as to drive the piezoelectric actuator to work; the current detection circuit is used for detecting current flowing through the piezoelectric actuator so as to output a current detection signal; the first resistor assembly and the first sampling circuit sample the voltage at the two ends of the piezoelectric actuator so as to output a single-end voltage signal. The second resistor assembly and the second sampling circuit are used for sampling the current detection signal so as to output a single-end current signal; the control circuit outputs a test control signal of each frequency point, and obtains an impedance spectrum of the piezoelectric actuator according to each single-end voltage signal and each single-end current signal; wherein each single-end voltage signal and each single-end current signal are in one-to-one correspondence with each frequency point; therefore, the hardware design of the impedance spectrum measurement circuit of the piezoelectric actuator is simplified, and the cost is saved.

Description

Technical Field

[0001] The present application belongs to the field of electronic circuit technology, and in particular relates to an impedance spectrum measurement circuit and chip of a piezoelectric actuator, and an electronic device. Background Art

[0002] The impedance spectrum measuring device of the related piezoelectric actuator includes: a sampling resistor, a parallel resistor, a first electromagnetic relay, a parallel capacitor, a second electromagnetic relay, a function generator, a voltage amplifier, a first digital multimeter, a second digital multimeter and a computer; wherein the piezoelectric actuator to be measured is connected in series with the sampling resistor, and the resistance of the sampling resistor is much smaller than the minimum impedance value of the piezoelectric actuator to be measured within the measurement frequency range; the parallel resistor is connected in series with the first electromagnetic relay and then in parallel with the piezoelectric actuator to be measured; the parallel capacitor is connected in series with the second electromagnetic relay and then in parallel with the piezoelectric actuator to be measured; the piezoelectric actuator to be measured and the sampling resistor connected in series are connected to the voltage amplifier; the voltage amplifier is connected to the function generator; the two ends of the piezoelectric actuator to be measured and the sampling resistor connected in series are connected to the first digital multimeter; the two ends of the sampling resistor are connected to the second digital multimeter; the first electromagnetic relay, the second electromagnetic relay, the function generator, the first digital multimeter and the second digital multimeter are connected to the computer.

[0003] It can be seen that the relevant impedance spectrum measurement device of the piezoelectric actuator includes multiple instruments, generators and computers, and the system is complex. Therefore, it is urgent to provide an impedance spectrum measurement circuit of the piezoelectric actuator to simplify the hardware design and save costs. Summary of the invention

[0004] The purpose of the present application is to provide an impedance spectrum measurement circuit and chip, and electronic equipment for a piezoelectric actuator, aiming to solve the problem of complex hardware design and high cost of the impedance spectrum measurement device of the related piezoelectric actuator.

[0005] The embodiment of the present application provides an impedance spectrum measurement circuit for a piezoelectric actuator, which is connected to a first resistor component, a second resistor component, a driving circuit, a current detection circuit, and a piezoelectric actuator; the driving circuit is used to output a driving signal according to a test control signal to drive the piezoelectric actuator to work; the current detection circuit is used to detect the current flowing through the piezoelectric actuator to output a current detection signal; The impedance spectrum measurement circuit of the piezoelectric actuator includes a first sampling circuit, a second sampling circuit and a control circuit; The first sampling circuit is connected to the first resistance component, and the first resistance component and the first sampling circuit are used to sample the voltage across the piezoelectric actuator to output a single-ended voltage signal; The second sampling circuit is connected to the second resistance component, and the second resistance component and the second sampling circuit are used to sample the current detection signal to output a single-ended current signal; The control circuit is connected to the first sampling circuit, the second sampling circuit and the driving circuit, and is used to output test control signals of various frequencies, and obtain an impedance spectrum of the piezoelectric actuator according to each of the single-ended voltage signals and each of the single-ended current signals; Wherein, each of the single-ended voltage signals and each of the single-ended current signals corresponds one-to-one to each frequency point.

[0006] In one embodiment, the control circuit is specifically used to output the test control signal of each frequency point, and use the difference between the maximum value of each single-ended voltage signal and the minimum value of each single-ended voltage signal as each first voltage, use the difference between the maximum value of each single-ended current signal and the minimum value of each single-ended current signal as each first current, and use the quotient of each first voltage and each first current as the impedance of the piezoelectric actuator corresponding to each frequency point; The impedance spectrum includes the impedance of the piezoelectric actuator corresponding to each frequency point.

[0007] In one of the embodiments, the control circuit is further used to obtain a target frequency based on the impedance spectrum and output a target control signal of the target frequency; The driving circuit is used to output a driving signal according to the target control signal to drive the piezoelectric actuator to operate.

[0008] In one embodiment, the control circuit is specifically used to obtain the maximum impedance and the minimum impedance based on the impedance spectrum, and the frequency corresponding to the average value of the maximum impedance and the minimum impedance is used as the target frequency, and output a target control signal of the target frequency.

[0009] In one embodiment, it also includes: a phase difference circuit, connected to the first sampling circuit, the second sampling circuit and the control circuit, and configured to output a phase difference signal according to the single-ended voltage signal and the single-ended current signal; the phase difference signal represents a phase difference between the single-ended voltage signal and the single-ended current signal at a target frequency; The control circuit is also used to record the characteristic parameter of the phase difference signal in real time, and adjust the target frequency of the control signal so that the change value of the characteristic parameter is less than a preset value.

[0010] In one embodiment, the phase difference circuit includes: a first comparison circuit, connected to the first sampling circuit, for comparing the single-ended voltage signal with a first reference voltage, and outputting a digital voltage signal according to a comparison result; a second comparison circuit, connected to the second sampling circuit, for comparing the single-ended current signal with a second reference voltage, and outputting a digital current signal according to a comparison result; a logic circuit connected to the first sampling circuit and the second sampling circuit, and configured to perform logic processing on the digital voltage signal and the digital current signal to output a logic signal; the logic signal represents the similarities and differences between the polarities of the digital voltage signal and the digital current signal; The pulse width measurement circuit is connected to the logic circuit and the control circuit, and is used to output the phase difference signal based on the logic signal.

[0011] In one embodiment, the control circuit comprises: A selection circuit, connected to the first sampling circuit and the second sampling circuit, for sequentially selecting and outputting the polarity of the single-ended voltage signal and the single-ended current signal based on a selection signal; an analog-to-digital conversion circuit, connected to the selection circuit, and configured to convert the single-ended voltage signal into a voltage digital signal, and convert the single-ended current signal into a current digital signal; The processing circuit is connected to the analog-to-digital conversion circuit, and is used to output the test control signal of each frequency point, and obtain the impedance of each piezoelectric actuator according to each voltage digital signal and each current digital signal.

[0012] In one embodiment, the processing circuit comprises: A calculation circuit, connected to the analog-to-digital conversion circuit, for obtaining the impedance of each of the piezoelectric actuators according to each of the voltage digital signals and each of the current digital signals; A processor connected to the calculation circuit and the drive circuit, configured to output the test control signal at each frequency point, obtain an impedance spectrum according to the impedance of each piezoelectric actuator, obtain a target frequency point based on the impedance spectrum, and output a target control signal at the target frequency point; The driving circuit is used to output a driving signal according to the target control signal to drive the piezoelectric actuator to operate.

[0013] In one of the embodiments, the first sampling circuit includes a third resistor component, a first protection circuit and a first conversion circuit; The third resistor component is connected to the first resistor component, and the first resistor component and the third resistor component are used to sample and limit the voltage across the piezoelectric actuator to output a voltage limiting signal; The first protection circuit is connected to the third resistance component and the first resistance component, and is used to perform overvoltage protection on the voltage limiting signal; The first conversion circuit is connected to the first protection circuit, the third resistance component and the control circuit, and is used for converting the voltage limiting signal after overvoltage protection into a single-ended voltage signal.

[0014] In one embodiment, the second sampling circuit includes a fourth resistor component, a second protection circuit and a second conversion circuit; The fourth resistor component is connected to the second resistor component, and the second resistor component and the fourth resistor component are used to limit the current detection signal to output a current limit signal; The second protection circuit is connected to the fourth resistance component and the second resistance component, and is used to perform overvoltage protection on the current limiting signal; The second conversion circuit is connected to the second protection circuit, the fourth resistor component and the control circuit, and is used to convert the current limiting signal after overvoltage protection into a single-ended current signal.

[0015] An embodiment of the present invention further provides a chip, wherein the chip includes the impedance spectrum measurement circuit of the piezoelectric actuator mentioned above.

[0016] An embodiment of the present invention further provides an electronic device, wherein the electronic device includes the impedance spectrum measurement circuit of the piezoelectric actuator described above.

[0017] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: since the driving circuit outputs a driving signal according to a test control signal to drive the piezoelectric actuator to work; the current detection circuit is used to detect the current flowing through the piezoelectric actuator to output a current detection signal; the first resistor component and the first sampling circuit sample the voltage across the piezoelectric actuator to output a single-ended voltage signal; the second resistor component and the second sampling circuit sample the current detection signal to output a single-ended current signal; the control circuit outputs a test control signal of each frequency point, and obtains the impedance spectrum of the piezoelectric actuator according to each single-ended voltage signal and each single-ended current signal; wherein each single-ended voltage signal and each single-ended current signal corresponds to each frequency point one by one; therefore, there is no need to configure multiple instruments, generators and computers, which simplifies the hardware design of the impedance spectrum measurement circuit of the piezoelectric actuator and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical invention in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of a structure of an impedance spectrum measurement circuit for a piezoelectric actuator provided in one embodiment of the present application; Figure 2 Another structural schematic diagram of an impedance spectrum measurement circuit for a piezoelectric actuator provided in one embodiment of the present application; Figure 3 A schematic diagram of a structure of a phase difference circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided in an embodiment of the present application; Figure 4 A schematic diagram of a structure of a control circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided in an embodiment of the present application; Figure 5 A schematic diagram of a structure of a processing circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of a first sampling circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided in an embodiment of the present application; Figure 7 A schematic structural diagram of a second sampling circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided in an embodiment of the present application; Figure 8 A partial exemplary circuit schematic diagram of an impedance spectrum measurement circuit for a piezoelectric actuator provided in an embodiment of the present application; Fig. 9 A partial exemplary circuit schematic diagram of an impedance spectrum measurement circuit for a piezoelectric actuator provided in an embodiment of the present application; Fig.10 A partial exemplary circuit schematic diagram of an impedance spectrum measurement circuit for a piezoelectric actuator provided in an embodiment of the present application; Fig.11 A partial exemplary circuit schematic diagram of a first sampling circuit in an impedance spectrum measurement circuit for a piezoelectric actuator provided in an embodiment of the present application; Fig.12 A partial exemplary circuit schematic diagram of a first sampling circuit in an impedance spectrum measurement circuit for a piezoelectric actuator provided in an embodiment of the present application; Fig.13 A partial exemplary circuit schematic diagram of a phase difference circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided in an embodiment of the present application; Fig.14Another partial exemplary circuit schematic diagram of a phase difference circuit in an impedance spectrum measurement circuit for a piezoelectric actuator provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0022] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0024] Figure 1 The structure diagram of the impedance spectrum measurement circuit of the piezoelectric actuator provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows: The impedance spectrum measurement circuit of the piezoelectric actuator is connected to the first resistor component 10, the second resistor component 20, the drive circuit 30, the current detection circuit 40 and the piezoelectric actuator; the drive circuit 30 is used to output a drive signal according to a test control signal to drive the piezoelectric actuator to work; the current detection circuit 40 is used to detect the current flowing through the piezoelectric actuator to output a current detection signal.

[0025] The impedance spectrum measurement circuit of the piezoelectric actuator includes a first sampling circuit 01 , a second sampling circuit 02 and a control circuit 03 .

[0026] The first sampling circuit 01 is connected to the first resistor component 10 , and the first resistor component 10 and the first sampling circuit 01 are used to sample the voltage across the piezoelectric actuator to output a single-ended voltage signal.

[0027] The second sampling circuit 02 is connected to the second resistor component 20 , and the second resistor component 20 and the second sampling circuit 02 are used to sample the current detection signal to output a single-ended current signal.

[0028] The control circuit 03 is connected to the first sampling circuit 01, the second sampling circuit 02 and the driving circuit 30, and is used to output test control signals of various frequency points, and obtain the impedance spectrum of the piezoelectric actuator according to each single-ended voltage signal and each single-ended current signal.

[0029] Among them, each single-ended voltage signal and each single-ended current signal corresponds to each frequency point one by one.

[0030] It can be understood that the control circuit 03 outputs the test control signals of each frequency point in sequence, and obtains the impedance of the piezoelectric actuator at each frequency point according to the received single-ended voltage signal corresponding to each frequency point and the single-ended current signal corresponding to each frequency point, and obtains the impedance spectrum of the piezoelectric actuator according to the impedance of the piezoelectric actuator at each frequency point.

[0031] It should be noted that the control circuit 03 is specifically used to output the test control signal of each frequency point, and use the difference between the maximum value of each single-ended voltage signal and the minimum value of each single-ended voltage signal as each first voltage, use the difference between the maximum value of each single-ended current signal and the minimum value of each single-ended current signal as each first current, and use the quotient of each first voltage and each first current as the impedance of the piezoelectric actuator corresponding to each frequency point; wherein the impedance spectrum includes the impedance of the piezoelectric actuator corresponding to each frequency point.

[0032] Through the above technical solution, the impedance of the piezoelectric actuator corresponding to each frequency point is accurately calculated, thereby improving the accuracy of the impedance spectrum of the piezoelectric actuator.

[0033] It is worth emphasizing that the control circuit 03 is also used to obtain a target frequency point based on the impedance spectrum and output a target control signal of the target frequency point.

[0034] The driving circuit 30 is used to output a driving signal according to the target control signal to drive the piezoelectric actuator to work.

[0035] Through the above technical solution, the piezoelectric actuator works in a resistive state, the piezoelectric actuator has a maximum amplitude and a minimum loss, and the working performance of the piezoelectric actuator is improved.

[0036] It can be understood that the control circuit 03 is specifically used to obtain the maximum impedance and the minimum impedance based on the impedance spectrum, and the frequency corresponding to the average value of the maximum impedance and the minimum impedance is used as the target frequency, and output the target control signal of the target frequency.

[0037] It can be understood that at the frequency points corresponding to the maximum impedance and the minimum impedance in the impedance spectrum, the piezoelectric actuator exhibits maximum capacitance and maximum inductance, respectively. Therefore, the frequency point corresponding to the average value of the maximum impedance and the minimum impedance is used as the target frequency point, and the target frequency point that makes the piezoelectric actuator work in a resistive state is obtained, thereby improving the working performance of the piezoelectric actuator.

[0038] like Figure 2 As shown, the impedance spectrum measurement circuit of the piezoelectric actuator further includes a phase difference circuit 04 .

[0039] The phase difference circuit 04 is connected to the first sampling circuit 01, the second sampling circuit 02 and the control circuit 03, and is used to output a phase difference signal according to the single-ended voltage signal and the single-ended current signal; the phase difference signal represents the phase difference between the single-ended voltage signal and the single-ended current signal at the target frequency.

[0040] The control circuit 03 is also used to record the characteristic parameters of the phase difference signal in real time, and adjust the target frequency of the control signal so that the change value of the characteristic parameter is less than a preset value.

[0041] It is understandable that the resonant frequency and anti-resonant frequency will change with changes in temperature and lifespan. If the operating frequency is not adjusted accordingly, the piezoelectric actuator may deviate from the working state, resulting in performance degradation, such as: smaller amplitude, greater energy consumption, device heating, etc. Therefore, it is necessary to monitor the phase difference of the piezoelectric actuator to dynamically adjust the operating frequency to ensure that the piezoelectric actuator works in the most suitable state.

[0042] like Figure 3 As shown, the phase difference circuit 04 includes a first comparison circuit 041 , a second comparison circuit 042 , a logic circuit 043 and a pulse width measurement circuit 044 .

[0043] The first comparison circuit 041 is connected to the first sampling circuit 01 and is used to compare the single-ended voltage signal with the first reference voltage and output a digital voltage signal according to the comparison result.

[0044] The second comparison circuit 042 is connected to the second sampling circuit 02, and is used to compare the single-ended current signal with the second reference voltage, and output a digital current signal according to the comparison result.

[0045] The logic circuit 043 is connected to the first sampling circuit 01 and the second sampling circuit 02, and is used to perform logic processing on the digital voltage signal and the digital current signal to output a logic signal; the logic signal represents the similarities and differences between the polarities of the digital voltage signal and the digital current signal.

[0046] The pulse width measurement circuit 044 is connected to the logic circuit 043 and the control circuit 03, and is used to output a phase difference signal based on the logic signal.

[0047] It can be understood that the analog single-ended voltage signal is converted into a digital voltage signal through the first comparison circuit 041, the analog single-ended current signal is converted into a digital current signal through the second comparison circuit 042, and a logic signal representing the differences and similarities between the polarity of the digital voltage signal and the polarity of the digital current signal is obtained through the logic circuit 043, and then a phase difference signal is obtained according to the duration of a preset level in the logic signal according to the pulse width measurement circuit 044.

[0048] The phase difference circuit 04 has a simple structure and low hardware cost.

[0049] like Figure 4 As shown, the control circuit 03 includes a selection circuit 031 , an analog-to-digital conversion circuit 032 and a processing circuit 033 .

[0050] The selection circuit 031 is connected to the first sampling circuit 01 and the second sampling circuit 02 , and is used to sequentially select the polarity of the output single-ended voltage signal and the single-ended current signal based on the selection signal.

[0051] The analog-to-digital conversion circuit 032 is connected to the selection circuit 031 and is used to convert the single-ended voltage signal into a voltage digital signal and convert the single-ended current signal into a current digital signal.

[0052] The processing circuit 033 is connected to the analog-to-digital conversion circuit 032, and is used to output the test control signal of each frequency point, and obtain the impedance of each piezoelectric actuator according to each voltage digital signal and each current digital signal.

[0053] The selection circuit 031 sequentially selects the polarity of the output single-ended voltage signal and the single-ended current signal, thereby saving port resources of the microprocessor 332 in the processing circuit 033 .

[0054] like Figure 5 As shown, the processing circuit 033 includes a computing circuit 331 and a processor 332 .

[0055] The calculation circuit 331 is connected to the analog-to-digital conversion circuit 032, and is used to obtain the impedance of each piezoelectric actuator according to each voltage digital signal and each current digital signal.

[0056] The processor 332 is connected to the calculation circuit 331 and the driving circuit 30, and is used to output the test control signal of each frequency point, obtain the impedance spectrum according to the impedance of each piezoelectric actuator, obtain the target frequency point based on the impedance spectrum, and output the target control signal of the target frequency point.

[0057] The driving circuit 30 is used to output a driving signal according to the target control signal to drive the piezoelectric actuator to work.

[0058] By setting the calculation circuit 331 to calculate the impedance of each piezoelectric actuator, the performance of the processing circuit 033 is enhanced.

[0059] like Figure 6 As shown, the first sampling circuit 01 includes a third resistance component 011 , a first protection circuit 012 and a first conversion circuit 013 .

[0060] The third resistor component 011 is connected to the first resistor component 10 , and the first resistor component 10 and the third resistor component 011 are used to sample and limit the voltage across the piezoelectric actuator to output a voltage limiting signal.

[0061] The first protection circuit 012 is connected to the third resistance component 011 and the first resistance component 10, and is used for performing overvoltage protection on the voltage limiting signal.

[0062] The first conversion circuit 013 is connected to the first protection circuit 012, the third resistance component 011 and the control circuit 03, and is used to convert the voltage limiting signal after overvoltage protection into a single-ended voltage signal.

[0063] Through the overvoltage protection function of the first protection circuit 012 and the limiting function of the third resistor component 011, a voltage limiting signal that meets the electrical characteristic requirements of the input port of the first conversion circuit 013 is obtained, and the double-ended voltage limiting signal is converted into a single-ended voltage signal through the first conversion circuit 013, thereby meeting the electrical characteristic requirements of the input port of the control circuit 03.

[0064] like Figure 7 As shown, the second sampling circuit 02 includes a fourth resistor component 021, a second protection circuit 022 and a second conversion circuit 023; The fourth resistor component 021 is connected to the second resistor component 20 , and the second resistor component 20 and the fourth resistor component 021 are used to limit the current detection signal to output a current limit signal.

[0065] The second protection circuit 022 is connected to the fourth resistor component 021 and the second resistor component 20 and is used for performing overvoltage protection on the current limiting signal.

[0066] The second conversion circuit 023 is connected to the second protection circuit 022, the fourth resistor component 021 and the control circuit 03, and is used to convert the current limiting signal after overvoltage protection into a single-ended current signal.

[0067] Through the overvoltage protection function of the second protection circuit 022 and the limiting function of the fourth resistor component 021, a current limiting signal that meets the electrical characteristic requirements of the input port of the second conversion circuit 023 is obtained, and the double-ended current limiting signal is converted into a single-ended current signal through the second conversion circuit 023, thereby meeting the electrical characteristic requirements of the input port of the control circuit 03.

[0068] Figures 8 to 10 A partial exemplary circuit structure of an impedance spectrum measurement circuit for a piezoelectric actuator provided by an embodiment of the present invention is shown. Fig.11 A partial exemplary circuit structure of a first sampling circuit in an impedance spectrum measurement circuit for a piezoelectric actuator provided by an embodiment of the present invention is shown. Fig.12 A partial exemplary circuit structure of a second sampling circuit in an impedance spectrum measurement circuit for a piezoelectric actuator provided by an embodiment of the present invention is shown. Fig.13 A partial exemplary circuit structure of a phase difference circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided by an embodiment of the present invention is shown. Fig.14 Another partial exemplary circuit structure of a phase difference circuit in an impedance spectrum measurement circuit of a piezoelectric actuator provided by an embodiment of the present invention is shown. For ease of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows: like Figure 8 As shown, the driving circuit 30 includes a first PMOS transistor PM1, a first NMOS transistor NM1 and a first inductor L1; the gate of the first PMOS transistor PM1 and the gate of the first NMOS transistor NM1 together constitute the input end of the driving circuit 30, which is connected to the control circuit 03 to receive the control signal; the drain of the first PMOS transistor PM1 is connected to the drain of the first NMOS transistor NM1 and the first end of the first inductor L1, and the second end of the first inductor L1 constitutes the output end of the driving circuit 30, which is connected to the piezoelectric actuator to output the driving signal; the source of the first PMOS transistor PM1 is connected to the first power supply VAA, and the source of the first NMOS transistor NM1 is connected to the power ground.

[0069] like Fig. 9 and Fig.10As shown, the driving circuit 30 includes a second PMOS transistor PM2, a second NMOS transistor NM2, a third PMOS transistor PM3, a third NMOS transistor NM3 and a second inductor L2; the gate of the second PMOS transistor PM2, the gate of the second NMOS transistor NM2, the gate of the third PMOS transistor PM3 and the gate of the third NMOS transistor NM3 together constitute the input end of the driving circuit 30, which is connected to the control circuit 03 to receive the control signal; the drain of the second PMOS transistor PM2 is connected to the drain of the second NMOS transistor NM2 and the first inductor L 1, the drain of the third PMOS transistor PM3 is connected to the drain of the third NMOS transistor NM3 and the first end of the second inductor L2; the second end of the first inductor L1 and the second end of the second inductor L2 jointly constitute the output end of the driving circuit 30, which is connected to the piezoelectric actuator and the current detection circuit 40 to output the driving signal; the source of the second PMOS transistor PM2 and the source of the third PMOS transistor PM3 are commonly connected to the first power supply VAA, and the source of the second NMOS transistor NM2 and the source of the third NMOS transistor NM3 are commonly connected to the power ground.

[0070] like Figure 8 and Fig. 9 As shown, the first resistor component 10 includes a first resistor R1 and a second resistor R2; the first end of the first resistor R1 is connected to the first end of the piezoelectric actuator, the first end of the second resistor R2 is connected to the second end of the piezoelectric actuator, and the second end of the first resistor R1 and the second end of the second resistor R2 are both connected to the third resistor component 011. The second resistor component 20 includes a third resistor R3 and a second resistor R2; the first end of the third resistor R3 is connected to the second end of the current detection circuit 40, the first end of the second resistor R2 is connected to the second end of the piezoelectric actuator and the first end of the current detection circuit 40, and the second end of the third resistor R3 and the second end of the second resistor R2 are both connected to the fourth resistor component 021.

[0071] like Fig.10 As shown, the first resistor component 10 includes a fourth resistor R4 and a fifth resistor R5; the first end of the fourth resistor R4 is connected to the first end of the piezoelectric actuator, the first end of the fifth resistor R5 is connected to the second end of the piezoelectric actuator, and the second end of the fourth resistor R4 and the second end of the fifth resistor R5 are both connected to the third resistor component 011. The second resistor component 20 includes a sixth resistor R6 and a seventh resistor R7; the first end of the seventh resistor R7 is connected to the second end of the current detection circuit 40, the first end of the sixth resistor R6 is connected to the second end of the piezoelectric actuator and the first end of the current detection circuit 40, and the second end of the seventh resistor R7 and the second end of the sixth resistor R6 are both connected to the fourth resistor component 021.

[0072] like Figures 8 to 10As shown, the current detection circuit 40 includes a detection resistor R0 ; a first end of the detection resistor R0 constitutes a first end of the current detection circuit 40 , and a second end of the detection resistor R0 constitutes a second end of the current detection circuit 40 .

[0073] like Fig.11 and Fig.12 As shown, the third resistor component 011 and the fourth resistor component 021 both include a resistor module; the resistor module includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and an eleventh resistor R11; the first end of the eighth resistor R8 and the first end of the tenth resistor R10 are commonly connected to the second power supply VBB, the first end of the ninth resistor R9 and the first end of the eleventh resistor R11 are commonly connected to the power ground, and the second end of the eighth resistor R8, the second end of the ninth resistor R9, the second end of the tenth resistor R10 and the second end of the eleventh resistor R11 constitute the input and output ends of the resistor module.

[0074] It can be understood that when the resistance module is applied to the third resistance component 011, the input and output ends of the resistance module are connected to the first resistance component 10, the first protection circuit 012 and the first conversion circuit 013; when the resistance module is applied to the fourth resistance component 021, the input and output ends of the resistance module are connected to the second resistance component 20, the second protection circuit 022 and the second conversion circuit 023.

[0075] like Fig.11 and Fig.12 As shown, the first protection circuit 012 and the second protection circuit 022 both include a protection module; the protection module includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; the cathode of the first diode D1 and the cathode of the third diode D3 are connected to the second power supply VBB; the anode of the second diode D2 and the anode of the fourth diode D4 are connected to the power ground; the anode of the first diode D1, the cathode of the second diode D2, the anode of the third diode D3 and the cathode of the fourth diode D4 constitute the input and output ends of the protection module.

[0076] It can be understood that, when the protection module is applied to the first protection circuit 012, the input and output ends of the protection module are connected to the first resistor component 10, the third resistor component 011 and the first conversion circuit 013 to access the voltage limiting signal and output the voltage limiting signal after overvoltage protection; when the protection module is applied to the second protection circuit 022, the input and output ends of the protection module are connected to the second resistor component 20, the fourth resistor component 021 and the second conversion circuit 023 to access the current limiting signal and output the current limiting signal after overvoltage protection.

[0077] like Fig.11 and Fig.12As shown, the first conversion circuit 013 and the second conversion circuit 023 include a conversion module; the conversion module includes a first operational amplifier U1, a second operational amplifier U2, a third operational amplifier U3, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16 and a seventeenth resistor R17; the positive phase input terminal of the first operational amplifier U1 and the positive phase input terminal of the second operational amplifier U2 together constitute the input terminal of the conversion module; the inverting input terminal of the first operational amplifier U1 is connected to the first end of the twelfth resistor R12 and the first end of the thirteenth resistor R13, and the inverting input terminal of the second operational amplifier U2 is connected to the inverting input terminal of the twelfth resistor R12. The second end is connected to the first end of the fourteenth resistor R14, the output end of the first operational amplifier U1 is connected to the second end of the thirteenth resistor R13 and the first end of the fifteenth resistor R15, the output end of the second operational amplifier U2 is connected to the second end of the fourteenth resistor R14 and the first end of the seventeenth resistor R17; the inverting input end of the third operational amplifier U3 is connected to the second end of the fifteenth resistor R15 and the first end of the sixteenth resistor R16, the non-inverting input end of the third operational amplifier U3 is connected to the first end of the seventeenth resistor R17 and connected to the reference voltage VBIAS, the output end of the third operational amplifier U3 and the second end of the sixteenth resistor R16 are connected and together constitute the output end of the conversion module.

[0078] It can be understood that, when the conversion module is applied to the first conversion circuit 013, the input end of the conversion module is connected to the first resistor component 10, the third resistor component 011 and the first protection circuit 012 to access the voltage limiting signal after overvoltage protection; the output end of the conversion module is connected to the control circuit 03 and the phase difference circuit 04 to output a single-ended voltage signal; when the conversion module is applied to the second conversion circuit 023, the input end of the conversion module is connected to the second resistor component 20, the fourth resistor component 021 and the second protection circuit 022 to access the current limiting signal after overvoltage protection; the output end of the conversion module is connected to the control circuit 03 and the phase difference circuit 04 to output a single-ended current signal.

[0079] like Fig.13 and Fig.14 As shown, the first comparison circuit 041 includes a first comparator U4; the non-inverting input terminal of the first comparator U4 constitutes the input terminal of the first comparison circuit 041, and is connected to the first sampling circuit 01 to access the single-ended voltage signal; the inverting input terminal of the first comparator U4 is connected to the first reference voltage VREF1; the output terminal of the first comparator U4 constitutes the output terminal of the first comparison circuit 041, and is connected to the logic circuit 043 to output a digital voltage signal.

[0080] like Fig.13 and Fig.14As shown, the second comparison circuit 042 includes a second comparator U5; the non-inverting input terminal of the second comparator U5 constitutes the input terminal of the second comparison circuit 042, and is connected to the second sampling circuit 02 to access the single-ended current signal; the inverting input terminal of the second comparator U5 is connected to the second reference voltage VREF2; the output terminal of the second comparator U5 constitutes the output terminal of the second comparison circuit 042, and is connected to the logic circuit 043 to output the digital current signal.

[0081] like Fig.13 As shown, the logic circuit 043 includes a first D flip-flop U6, a second D flip-flop U7 and a NAND gate U8; the data terminal D of the first D flip-flop U6 and the data terminal D of the second D flip-flop U7 are commonly connected to the high level signal V1; the clock terminal CP of the first D flip-flop U6 constitutes the digital voltage signal input terminal of the logic circuit 043, which is connected to the first comparison circuit 041 to access the digital voltage signal; the clock terminal CP of the second D flip-flop U7 constitutes the digital current signal input terminal of the logic circuit 043, which is connected to the second comparison circuit 042 to access the digital current signal; the output terminal Q of the first D flip-flop U6, the output terminal Q of the second D flip-flop U7, the first input terminal of the NAND gate U8 and the second input terminal of the NAND gate U8 jointly constitute the logic signal output terminal of the logic circuit 043, which is connected to the pulse width measurement circuit 044 to output the logic signal; the output terminal of the NAND gate U8 is connected to the clear terminal / Clear of the first D flip-flop U6 and the clear terminal / Clear of the second D flip-flop U7.

[0082] like Fig.13 As shown, the pulse width measurement circuit 044 includes a first current source I1, a second current source I2, a first capacitor C1, a second capacitor C2 and an eighteenth resistor R18; the positive electrode of the first current source I1 is connected to the third power supply VCC, the control end of the first current source I1 and the control end of the second current source I2 together constitute the input end of the pulse width measurement circuit 044, which is connected to the logic circuit 043 to access the logic signal; the negative electrode of the first current source I1, the positive electrode of the second current source I2, the first end of the first capacitor C1 and the first end of the eighteenth resistor R18 together constitute the output end of the pulse width measurement circuit 044, which is connected to the control circuit 03 to output the phase difference signal; the second end of the eighteenth resistor R18 is connected to the first end of the second capacitor C2, and the negative electrode of the second current source I2, the second end of the first capacitor C1 and the second end of the second capacitor C2 are commonly connected to the power ground.

[0083] like Fig.14As shown, the logic circuit 043 includes an XOR gate U9; the first input end of the XOR gate U9 constitutes a digital voltage signal input end of the logic circuit 043, which is connected to the first comparison circuit 041 to access the digital voltage signal; the second input end of the XOR gate U9 constitutes a digital current signal input end of the logic circuit 043, which is connected to the second comparison circuit 042 to access the digital current signal; the output end of the XOR gate U9 constitutes a logic signal output end of the logic circuit 043, which is connected to the pulse width measurement circuit 044 to output a logic signal.

[0084] like Fig.14 As shown, the pulse width measurement circuit 044 includes a counter U10, which is used to count the internal clock when receiving the first jump edge in the logic signal, and return to zero to re-count according to the second jump edge in the logic signal, and generate a phase difference signal according to the counting result; wherein the first jump edge and the second jump edge have opposite jump directions.

[0085] The following is a combination of working principles Figure 8 As shown for further explanation: exist Figures 8 to 10 In the embodiment, the control circuit 03 sequentially outputs control signals of various frequencies, and the driving circuit 30 sequentially outputs driving signals of various frequencies according to the various control signals.

[0086] Driven by the driving signals at each frequency point, the following actions are performed in sequence: the piezoelectric actuator works according to the driving signal; Figure 8 and Fig.11 or combined Fig. 9 and Fig.11The first resistor R1 and the eighth resistor R8 and the ninth resistor R9 in the third resistor component 011 limit the voltage at the first end of the piezoelectric actuator. The first diode D1 and the second diode D2 in the first protection circuit 012 perform voltage protection on the voltage at the first end of the piezoelectric actuator after limiting, and input the voltage at the first end of the piezoelectric actuator after voltage protection to the first conversion circuit 013. In the first conversion circuit 013, the non-inverting input terminal of the first operational amplifier U1 is connected to the voltage at the first end of the piezoelectric actuator after voltage protection. The first operational amplifier U1 follows the voltage at the first end of the piezoelectric actuator after voltage protection, and inputs the voltage at the first end of the piezoelectric actuator after following to the inverting input terminal of the third operational amplifier. The second resistor R2 and the third resistor component 011 The tenth resistor R10 and the eleventh resistor R11 limit the voltage at the second end of the piezoelectric actuator. The third diode D3 and the fourth diode D4 in the first protection circuit 012 protect the voltage at the second end of the piezoelectric actuator after limiting. The voltage at the second end of the piezoelectric actuator after voltage protection is input to the non-inverting input of the second operational amplifier U2 in the first conversion circuit 013. The second operational amplifier U2 follows the voltage at the second end of the piezoelectric actuator after voltage protection, and inputs the voltage at the second end of the piezoelectric actuator after following to the non-inverting input of the third operational amplifier U3. The third operational amplifier U3 performs a subtraction operation on the voltage at the second end of the piezoelectric actuator after voltage protection and the voltage at the first end of the piezoelectric actuator after voltage protection, thereby obtaining a single-ended voltage signal. Fig.10 and Fig.11 The process and combination of obtaining a single-ended voltage signal Figure 8 and Fig.11 The process of obtaining the single-ended voltage signal is similar, the only difference is that the structure of the first resistance component 10 is different, which will not be repeated here.

[0087] Combination Figure 8 and Fig.12 or combined Fig. 9 and Fig.12, the first resistor R1 and the eighth resistor R8 and the ninth resistor R9 in the fourth resistor component 021 limit the voltage of the first end of the detection resistor, the first diode D1 and the second diode D2 in the second protection circuit 022 perform voltage protection on the voltage of the first end of the detection resistor after limiting, and input the voltage of the first end of the detection resistor after voltage protection to the second conversion circuit 023, in the second conversion circuit 023, the non-inverting input terminal of the first operational amplifier U1 receives the voltage of the first end of the detection resistor, the first operational amplifier U1 follows the voltage of the first end of the detection resistor after voltage protection, and inputs the voltage of the first end of the detection resistor after following to the inverting input terminal of the third operational amplifier; the third resistor R3 and the eighth resistor R8 and the ninth resistor R9 in the fourth resistor component 021 limit the voltage of the first end of the detection resistor, the first diode D1 and the second diode D2 in the second protection circuit 022 perform voltage protection on the voltage of the first end of the detection resistor after limiting, and input the voltage of the first end of the detection resistor after voltage protection to the second conversion circuit 023, in the second conversion circuit 023, the non-inverting input terminal of the first operational amplifier U1 receives the voltage of the first end of the detection resistor, the first operational amplifier U1 follows the voltage of the first end of the detection resistor after voltage protection, and inputs the voltage of the first end of the detection resistor after following to the inverting input terminal of the third operational amplifier; The tenth resistor R10 and the eleventh resistor R11 limit the voltage at the second end of the detection resistor. The third diode D3 and the fourth diode D4 in the second protection circuit 022 perform voltage protection on the voltage at the second end of the detection resistor after limiting, and input the voltage at the second end of the detection resistor after voltage protection to the non-inverting input terminal of the second operational amplifier U2 in the second conversion circuit 023. The second operational amplifier U2 follows the voltage at the second end of the detection resistor after voltage protection, and inputs the voltage at the second end of the detection resistor after following to the non-inverting input terminal of the third operational amplifier U3. The third operational amplifier U3 performs a subtraction operation on the voltage at the second end of the detection resistor after voltage protection and the voltage at the first end of the detection resistor after voltage protection, thereby obtaining a single-ended current signal. Fig.10 and Fig.12 The process and combination of obtaining single-ended current signal Figure 8 and Fig.12 The process of obtaining the single-ended current signal is similar, the only difference is that the structure of the second resistance component 20 is different, which will not be repeated here.

[0088] The control circuit 03 uses the difference between the maximum value of each single-ended voltage signal and the minimum value of each single-ended voltage signal as each first voltage, uses the difference between the maximum value of each single-ended current signal and the minimum value of each single-ended current signal as each first current, and uses the quotient of each first voltage and each first current as the impedance of the piezoelectric actuator corresponding to each frequency point, thereby obtaining the impedance spectrum of the piezoelectric actuator; the control circuit 03 also obtains the maximum impedance and the minimum impedance based on the impedance spectrum, and the frequency point corresponding to the average value of the maximum impedance and the minimum impedance is used as the target frequency point, and outputs the target control signal of the target frequency point, so that the drive circuit 30 outputs the drive signal according to the target control signal to drive the piezoelectric actuator to work. Afterwards, as Fig.13 and Fig.14 As shown, the first comparator U4 compares the single-ended voltage signal with the first reference voltage, and outputs a digital voltage signal according to the comparison result; the second comparator U5 compares the single-ended current signal with the second reference voltage, and outputs a digital current signal according to the comparison result.

[0089] exist Fig.13 In the embodiment, when the digital voltage signal is at a high level and the digital current signal is at a low level, the first current source I1 is turned on, the second current source I2 is turned off, the first capacitor C1 is charged and outputs an energy storage voltage; when the digital voltage signal and the digital current signal are both at a high level, the first current source I1 and the second current source I2 are both turned off; when the digital voltage signal is at a low level and the digital current signal is at a high level, the first current source I1 is turned off, the second current source I2 is turned on, the first capacitor C1 is discharged and outputs an energy storage voltage; when the digital voltage signal and the digital current signal are both at a low level, the first current source I1 and the second current source I2 are both turned on; this cycle repeats itself, the first capacitor C1 outputs an energy storage voltage, the first resistor R1 and the second capacitor C2 filter the energy storage voltage to output a phase difference signal.

[0090] exist Fig.14 In the embodiment, XOR gate U9 is used; XOR gate U9 performs XOR operation on the digital voltage signal and the digital current signal to output a logic signal; at this time, the logic signal represents the difference between the polarity of the digital voltage signal and the polarity of the digital current signal. Counter U10 is used to count the internal clock when receiving the first transition edge in the logic signal, and return to zero to re-count according to the second transition edge in the logic signal, and generate a phase difference signal according to the counting result; wherein the first transition edge and the second transition edge have opposite transition directions.

[0091] The control circuit 03 records the characteristic parameters of the phase difference signal in real time, and adjusts the target frequency of the control signal so that the change value of the characteristic parameter is less than a preset value.

[0092] An embodiment of the present invention further provides a chip, which includes the impedance spectrum measurement circuit of the piezoelectric actuator mentioned above.

[0093] An embodiment of the present invention further provides an electronic device, which includes the impedance spectrum measurement circuit of the piezoelectric actuator mentioned above.

[0094] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0095] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An impedance spectrum measurement circuit for a piezoelectric actuator, characterized in that: connected to the first resistor component, the second resistor component, the driving circuit, the current detection circuit and the piezoelectric actuator; the driving circuit is used to output a driving signal according to the test control signal to drive the piezoelectric actuator to work; The current detection circuit is used to detect the current flowing through the piezoelectric actuator to output a current detection signal; The impedance spectrum measurement circuit of the piezoelectric actuator includes a first sampling circuit, a second sampling circuit and a control circuit; The first sampling circuit is connected to the first resistance component, and the first resistance component and the first sampling circuit are used to sample the voltage across the piezoelectric actuator to output a single-ended voltage signal; The second sampling circuit is connected to the second resistance component, and the second resistance component and the second sampling circuit are used to sample the current detection signal to output a single-ended current signal; The control circuit is connected to the first sampling circuit, the second sampling circuit and the driving circuit, and is used to output test control signals of various frequencies, and obtain an impedance spectrum of the piezoelectric actuator according to each of the single-ended voltage signals and each of the single-ended current signals; Wherein, each of the single-ended voltage signals and each of the single-ended current signals corresponds one-to-one to each frequency point.

2. The impedance spectrum measurement circuit of the piezoelectric actuator according to claim 1, characterized in that: The control circuit is specifically used to output the test control signal of each frequency point, and use the difference between the maximum value of each single-ended voltage signal and the minimum value of each single-ended voltage signal as each first voltage, use the difference between the maximum value of each single-ended current signal and the minimum value of each single-ended current signal as each first current, and use the quotient of each first voltage and each first current as the impedance of the piezoelectric actuator corresponding to each frequency point; The impedance spectrum includes the impedance of the piezoelectric actuator corresponding to each frequency point.

3. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 1, characterized in that: The control circuit is also used to obtain a target frequency point based on the impedance spectrum, and output a target control signal of the target frequency point; The driving circuit is used to output a driving signal according to the target control signal to drive the piezoelectric actuator to operate.

4. The impedance spectrum measurement circuit of the piezoelectric actuator according to claim 3, characterized in that: The control circuit is specifically used to obtain the maximum impedance and the minimum impedance based on the impedance spectrum, and the frequency point corresponding to the average value of the maximum impedance and the minimum impedance is used as the target frequency point, and output a target control signal of the target frequency point.

5. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 3, characterized in that: Also includes: a phase difference circuit, connected to the first sampling circuit, the second sampling circuit and the control circuit, and configured to output a phase difference signal according to the single-ended voltage signal and the single-ended current signal; The phase difference signal represents the phase difference between the single-ended voltage signal and the single-ended current signal at a target frequency; The control circuit is also used to record the characteristic parameter of the phase difference signal in real time, and adjust the target frequency of the control signal so that the change value of the characteristic parameter is less than a preset value.

6. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 5, characterized in that: The phase difference circuit comprises: a first comparison circuit, connected to the first sampling circuit, for comparing the single-ended voltage signal with a first reference voltage, and outputting a digital voltage signal according to a comparison result; a second comparison circuit, connected to the second sampling circuit, for comparing the single-ended current signal with a second reference voltage, and outputting a digital current signal according to a comparison result; a logic circuit connected to the first sampling circuit and the second sampling circuit, and configured to perform logic processing on the digital voltage signal and the digital current signal to output a logic signal; the logic signal represents the similarities and differences between the polarities of the digital voltage signal and the digital current signal; The pulse width measurement circuit is connected to the logic circuit and the control circuit, and is used to output the phase difference signal based on the logic signal.

7. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 1, characterized in that: The control circuit comprises: A selection circuit, connected to the first sampling circuit and the second sampling circuit, for sequentially selecting and outputting the polarity of the single-ended voltage signal and the single-ended current signal based on a selection signal; an analog-to-digital conversion circuit, connected to the selection circuit, and configured to convert the single-ended voltage signal into a voltage digital signal, and convert the single-ended current signal into a current digital signal; The processing circuit is connected to the analog-to-digital conversion circuit, and is used to output the test control signal of each frequency point, and obtain the impedance of each piezoelectric actuator according to each voltage digital signal and each current digital signal.

8. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 7, characterized in that: The processing circuit comprises: A calculation circuit, connected to the analog-to-digital conversion circuit, for obtaining the impedance of each of the piezoelectric actuators according to each of the voltage digital signals and each of the current digital signals; A processor connected to the calculation circuit and the drive circuit, configured to output the test control signal at each frequency point, obtain an impedance spectrum according to the impedance of each piezoelectric actuator, obtain a target frequency point based on the impedance spectrum, and output a target control signal at the target frequency point; The driving circuit is used to output a driving signal according to the target control signal to drive the piezoelectric actuator to operate.

9. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 1, characterized in that: The first sampling circuit includes a third resistor component, a first protection circuit and a first conversion circuit; The third resistor component is connected to the first resistor component, and the first resistor component and the third resistor component are used to sample and limit the voltage across the piezoelectric actuator to output a voltage limiting signal; The first protection circuit is connected to the third resistance component and the first resistance component, and is used to perform overvoltage protection on the voltage limiting signal; The first conversion circuit is connected to the first protection circuit, the third resistance component and the control circuit, and is used to convert the voltage limiting signal after overvoltage protection into a single-ended voltage signal.

10. The impedance spectrum measurement circuit of a piezoelectric actuator according to claim 1, characterized in that: The second sampling circuit includes a fourth resistance component, a second protection circuit and a second conversion circuit; The fourth resistor component is connected to the second resistor component, and the second resistor component and the fourth resistor component are used to limit the current detection signal to output a current limit signal; The second protection circuit is connected to the fourth resistance component and the second resistance component, and is used to perform overvoltage protection on the current limiting signal; The second conversion circuit is connected to the second protection circuit, the fourth resistor component and the control circuit, and is used to convert the current limiting signal after overvoltage protection into a single-ended current signal.

11. A chip, characterized in that: The chip includes the impedance spectrum measurement circuit of the piezoelectric actuator according to any one of claims 1 to 10.

12. An electronic device, characterized in that: The electronic device comprises the impedance spectrum measurement circuit of the piezoelectric actuator according to any one of claims 1 to 10.

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