Detection Circuit and Detection Method for MEMS Resonator

Abstract

The present invention provides a detection circuit and a detection method for a MEMS resonator. The detection circuit includes: a MEMS resonator; a charge amplifier, whose output terminal outputs a resonance induction signal; a rectifier, configured to flip or cut off the negative value part in the resonance induction signal to obtain a rectified resonance induction signal; an integrator, configured to integrate the rectified resonance induction signal with a set integration time as a period; a sampling circuit, sampling the output of the integrator to obtain an integration sampling value; a comparator, obtaining a digital square wave signal; a counter, which is triggered by a predetermined transition edge of the digital square wave signal for counting, and the count value per unit time is denoted as N1; a processing unit, which calculates the natural resonance frequency F0 based on the count value N1 and the unit time, and calculates the quality factor Q based on the natural resonance frequency F0 and the integration sampling value. In this way, the resonance frequency and quality factor of the MEMS resonator can be measured quickly and accurately.

Description

[Technical field]

[0001] The present invention relates to the technical field of micro-electro-mechanical systems (MEMS), and in particular to a detection circuit and a detection method for a MEMS resonator. [Background technology]

[0002] Currently, there are two main methods for detecting the resonance characteristics (natural resonance frequency F0 and quality factor Q) of MEMS resonators.

[0003] The first detection method is: through multiple frequency sweeps (coarse frequency sweep plus fine frequency sweep), the natural resonant frequency F0 corresponding to the maximum output signal, and the frequencies FL and FH corresponding to -3dB on both sides of F0 are obtained, such as Figure 2 As shown. The quality factor Q is calculated by the formula Q = F0 / (FH-FL). The shortcomings of this method are: due to the deviation of the processing technology, the resonant frequency distribution of MEMS products is relatively wide, that is, the range of frequency sweeping is relatively wide; in addition, the quality factor Q of the MEMS resonator is generally high: ranging from several thousand to hundreds of thousands, which requires multiple frequency sweeps to obtain the center frequency. In order to accurately obtain the center frequency and the frequency FL and FH corresponding to -3dB, the frequency step size during fine frequency sweeping must be very small. Taking the MEMS gyroscope with a natural resonant frequency of 20K Hz and a Q value of 10000 as an example, the frequency of the fine sweep needs to be set to 0.1Hz or less. This method takes a long time as a whole, which is very unfavorable for the testing of large-scale mass-produced devices.

[0004] The second detection method is: after stimulating the MEMS resonator to oscillate, measure the output amplitude attenuation curve, and obtain the natural resonant frequency F0 and quality factor Q by curve fitting. The main problem with this method is that in order to obtain a complete attenuation curve, sufficient sampling points are required within one vibration cycle (1 / F0), usually more than 40 points / cycle. Taking the MEMS gyroscope with a natural resonant frequency of 20KHz and a Q value of 10000 as an example, the sampling frequency needs to reach 800KHz. This places very stringent requirements on the bandwidth of the circuit and occupies too many circuit resources. In addition, the curve fitting formula is relatively complex and is only suitable for an external CPU (central processing unit). The process cannot be completed on the MEMS resonator chip itself.

[0005] Therefore, it is urgent to propose a new technical solution to solve the above problems. [Summary of the invention]

[0006] One of the purposes of the present invention is to provide a detection circuit and a detection method for a MEMS resonator, which only requires a small amount of resources to quickly and accurately measure the resonant frequency and quality factor of the MEMS resonator.

[0007] According to one aspect of the present invention, the present invention provides a detection circuit for a MEMS resonator, which includes: a MEMS resonator that enters a resonant state after being excited and then the excitation is removed; a first sensing capacitor, one end of which is coupled to the first end of the MEMS resonator; a second sensing capacitor, one end of which is coupled to the second end of the MEMS resonator; a charge amplifier, its first input terminal is coupled to the other end of the first sensing capacitor, its second input terminal is coupled to the other end of the second sensing capacitor, and its output terminal outputs a resonant sensing signal; a rectifier, its input terminal is coupled to the output terminal of the charge amplifier, and is used to flip or cut off the negative part in the resonant sensing signal to obtain a rectified resonant sensing signal; an integrator, which is configured to integrate the rectified resonant sensing signal with a set integration time as a period; a sampling circuit, which is configured to sample the resonant integration signal output by the integrator to obtain an integration sampling value; a comparator, which is used to compare the rectified resonant sensing signal with a predetermined threshold voltage to obtain a digital square wave signal; a counter, which counts with a predetermined transition edge of the digital square wave signal as a trigger signal, and the count value per unit time is denoted as N1; a processing unit, which calculates the natural resonant frequency F0 of the MEMS resonator according to the count value N1 and the unit time, and calculates the quality factor Q according to the natural resonant frequency F0 and the integration sampling value.

[0008] According to one aspect of the present invention, the present invention provides a detection method for a MEMS resonator, which includes: exciting the MEMS resonator and then removing the excitation to make the MEMS resonator enter a resonant state; the charge amplifier converts the sensing signals of the first sensing capacitor and the second sensing capacitor into a resonant sensing signal, where one end of the first sensing capacitor is coupled to the first end of the MEMS resonator, one end of the second sensing capacitor is coupled to the second end of the MEMS resonator, the first input terminal of the charge amplifier is coupled to the other end of the first sensing capacitor, the second input terminal of the charge amplifier is coupled to the other end of the second sensing capacitor, and the output terminal of the charge amplifier outputs the resonant sensing signal; flipping or cutting off the negative part in the resonant sensing signal to obtain a rectified resonant sensing signal; integrating the rectified resonant sensing signal with a set integration time as a period; sampling the resonant integration signal output by the integrator to obtain an integration sampling value; the comparator compares the rectified resonant sensing signal with a predetermined threshold voltage to obtain a digital square wave signal; counting with a predetermined transition edge of the digital square wave signal as a trigger signal, and the count value per unit time is denoted as N1; calculating the natural resonant frequency F0 of the MEMS resonator according to the count value N1 and the unit time, and calculating the quality factor Q according to the natural resonant frequency F0 and the integration sampling value.

[0009] Compared with the prior art, in the detection circuit and method of the MEMS resonator in the present invention, the rectified resonant induction signal is integrated with a set integration time as a period, and the counter counts with a predetermined transition edge of a digital square wave signal as a trigger signal. The count value per unit time is denoted as N1. The natural resonant frequency F0 of the MEMS resonator is calculated based on the count value N1 and the unit time. The quality factor Q is calculated based on the natural resonant frequency F0 and the integral sampling value. In this way, only a small amount of resources are required to quickly and accurately measure the quality factor Q and the natural resonant frequency F0 of the MEMS resonator, which is suitable for the effective testing of mass-produced devices.

Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for 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 those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0011] Figure 1 It is a schematic structural diagram of the detection circuit of the MEMS resonator in an embodiment of the present invention;

[0012] Figure 2 It is a corresponding relationship diagram between the resonant frequency and the signal assignment;

[0013] Figure 3 For Figure 1 the waveform schematic diagram of each signal in the detection circuit in

[0014] Figure 4 It is a schematic flow diagram of the detection method of the MEMS resonator in an embodiment of the present invention.

Detailed Embodiments

[0015] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0016] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments. Unless otherwise specified, the terms indicating electrical connection such as "connected", "coupled", and "joined" herein all mean direct or indirect electrical connection.

[0017] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0018] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected to", "coupled" and other terms should be understood in a broad sense; for example, it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0019] In view of the problems existing in the prior art, according to one aspect of the present invention, the present invention provides a detection circuit for a MEMS resonator. Figure 1 It is a schematic structural diagram of the detection circuit of the MEMS resonator in an embodiment of the present invention. As Figure 1 shown, the detection circuit includes a MEMS resonator 1, a first sensing capacitor 10, a second sensing capacitor 11, a charge amplifier 3, a rectifier 4, an integrator 5, a sampling circuit 6, a comparator 8, a counter 9 and a processor (not shown).

[0020] After the MEMS resonator 1 is excited and then the excitation is removed, the MEMS resonator enters the resonance state. In one embodiment, the detection circuit further includes a drive circuit 2. The drive circuit 2 provides the excitation by applying a voltage signal to the MEMS resonator, and then removes the excitation. The current mainstream detection scheme requires the drive circuit 2 to accurately adjust the resonance frequency F to the natural resonance frequency F0 of the MEMS resonator, and perform a fine frequency scan near it to obtain the frequencies FL and FH corresponding to -3dB, as Figure 2 shown. However, for the detection of the natural resonance frequency F0 and the quality factor Q of the present invention, it is not necessary for the drive circuit 2 to accurately excite to the natural resonance frequency F0 of the MEMS resonator. Only one rough scan is required, and the excitation frequency is adjusted to near F0. It only requires that the amplitude of the output signal of the MEMS resonator is within a range that can be accurately measured. Even if the original excitation frequency is not the natural resonance frequency F0, after the excitation is removed, the MEMS resonator 1 will automatically return to the natural resonance frequency F0. In another embodiment, the MEMS resonator can also be excited by an external physical method. For example, the external physical method can be tapping, vibration, sound wave, etc.

[0021] One end of the first sensing capacitor 10 is coupled to the first end of the MEMS resonator 1, and one end of the second sensing capacitor 11 is coupled to the second end of the MEMS resonator 1. The first input terminal of the charge amplifier 3 is coupled to the other end of the first sensing capacitor 10, and the second input terminal of the charge amplifier 3 is coupled to the other end of the second sensing capacitor 11. Its output terminal outputs a resonant induction signal 12. Currently, MEMS resonators, such as micromirrors, gyroscopes, etc., are mainly driven by electrostatic force. The vibration of the MEMS resonator will cause a differential change in the capacitance values of the first sensing capacitor 10 and the second sensing capacitor 11. When one capacitance value increases, the other capacitance value decreases; when one capacitance value decreases, the other capacitance value increases. The resonant induction signal 12 is a voltage signal, which can reflect the resonant state of the MEMS resonator 1. As Figure 3 shown, the amplitude of the resonant induction signal 12 gradually decays due to the removal of the excitation.

[0022] The positive and negative amplitudes of the resonant induction signal 12 after passing through the charge amplifier are symmetric and cannot be directly integrated. It is necessary to flip or cut off the negative value part located below the horizontal axis. The input terminal of the rectifier 4 is coupled to the output terminal of the charge amplifier 3, and is used to flip or cut off the negative value part in the resonant induction signal 12 to obtain a rectified resonant induction signal 13. In Figure 1 the shown embodiment, the rectifier 4 is a full-wave rectifier. The full-wave rectifier flips the negative value part in the resonant induction signal 12 into a positive value to obtain a rectified resonant induction signal 13. As Figure 3 shown, the rectified resonant induction signal 13 is all located above the horizontal axis. In another embodiment, the rectifier 4 can be a half-wave rectifier, and the half-wave rectifier cuts off the negative value part in the resonant induction signal 12 to obtain a rectified resonant induction signal.

[0023] The integrator 5 is configured to integrate the rectified resonant induction signal 13 at a set integration time t_int as a period to obtain a resonant integration signal 14. As Figure 3 shown, v1, v2, vi are the resonant integration signals 14. The number of periods of the rectified resonant induction signal 13 within a single set integration time is controlled by setting the integration time t_int. In one embodiment, the set integration time t_int is greater than or equal to 10 times the natural resonant period of the MEMS resonator. For example, the set integration time t_int is usually set to dozens to hundreds of natural resonant periods.

[0024] The sampling circuit 6 is configured to sample the resonant integration signal 14 output by the integrator 5 to obtain an integrated sampling value. This integrated sampling value can be used to solve for the quality factor Q. As described above, the integration time t_int can be set to dozens to hundreds of resonant periods. Taking a gyro with a resonant frequency of 20KHz as an example, if the integration time t_int is set to 40 times the resonant period, the signal output frequency is 500Hz. Compared with the prior art method of measuring the complete decay curve, the bandwidth of the sampling circuit 6 can be reduced from 800KHz to 500Hz, and this function can be achieved by general sampling circuits.

[0025] In a specific embodiment, the detection circuit further includes an analog-to-digital converter 7, and the analog-to-digital converter 7 is used to perform analog-to-digital conversion on the integrated sampling value, so that the processing unit can process according to the integrated sampling value after analog-to-digital conversion. Of course, in other embodiments, the analog-to-digital converter 7 can also be placed in front of the rectifier 4 or the charge amplifier 3 in advance.

[0026] The rectified resonant induction signal 13 is also output to the comparator 8 at the same time. A predetermined threshold voltage Vt is set for the comparator 8, and the comparator 8 compares the rectified resonant induction signal 13 with the predetermined threshold voltage Vt, so as to convert the rectified resonant induction signal 13 into a digital square wave signal 15 with the same frequency. In a specific example, the comparator 8 outputs a high level when the rectified resonant induction signal 13 is greater than the predetermined threshold voltage Vt, and outputs a low level when the rectified resonant induction signal 13 is less than the predetermined threshold voltage Vt.

[0027] The counter 9 counts with the predetermined transition edge of the digital square wave signal 15 as the trigger signal, and the count value in the unit time t_unit is denoted as N1. Specifically, the predetermined transition edge is the rising edge. When the trigger signal is the rising edge, the count value of the counter 9 is incremented by 1 until the unit time t_unit ends to obtain the count value N1.

[0028] The processing unit calculates the natural resonant frequency F0 of the MEMS resonator 1 based on the count value N1 and the unit time t_unit. In the case where the negative part in the resonant induction signal is flipped to a positive value, F0 = N1 / (2*t_unit), as Figure 3 shown. In the case where the negative part in the resonant induction signal is chopped off, F0 = N1 / t_unit.

[0029] The processing unit calculates the quality factor Q based on the natural resonant frequency F0 and the integrated sampling value. Specifically, the quality factor Q is calculated according to the following formula:

[0030]

[0031] where ω = 2πF0, v i is the i-th integral sampling value, where i is greater than or equal to 2 and less than or equal to n, and n is the number of integral sampling values, v1 is the first integral sampling value, t _int is the set integral time

[0032] The above final expression can be derived according to the following process:

[0033] The resonant induction signal 12 output by the charge amplifier 3 is:

[0034]

[0035] where A0 is the initial amplitude of the signal, ω is the angular frequency, and Q is the quality factor.

[0036] The rectified resonant induction signal 13 output by the full-wave rectifier 4 is:

[0037]

[0038] The resonant integration signal 14 output by the integrator 5 is:

[0039]

[0040] Simplify formula (3) to get:

[0041]

[0042] Based on formula (4), the final expression (5) in the above text can be further derived.

[0043] Regarding the calculation of the quality factor Q, formulas 1, 2, and 3 contain the product of trigonometric functions and exponential functions. Most existing technologies use a high-speed sampling circuit for sampling and then use formula 1 for fitting to obtain the Q value. Such an algorithm requires an external computing unit, such as an MCU or a PC, to implement, and it also takes a long time, which is obviously not suitable for mass production test products. One of the key points of the present invention is to simplify the algorithm to form the above final expression (5). This expression only requires a few addition, subtraction, multiplication, and division operations, as well as one square root operation to complete, and the required computing power is greatly reduced, and the processing speed is significantly increased. In other words, the present invention can quickly and accurately measure the natural resonance frequency F0 and the quality factor Q by consuming very few resources, and it is a factory test scheme suitable for mass-produced products. Since few resources are required, the detection circuit in the present invention can be directly integrated inside the chip.

[0044] As shown in the following table, through verification, it is found that for Q values between 7000 and 10000, when calculating with a sample of 10 data points, the accuracy of the present invention can reach 5%, which is sufficient to meet most test requirements.

[0045] Actual Q value 10000 8000 7000 Q value obtained by this algorithm 9563 7734 6821 Error -4％ -3％ -3％

[0046] Taking a MEMS gyroscope as an example, there are tens of thousands of chips on a single wafer. If measured by the traditional method of multiple scans, each chip needs to be scanned at least 2 to 3 times, with each scan time being about 20 s, and 8 devices are tested each time, then it takes at least about 14 hours. However, the present invention only needs one rough scan to complete, and the test time can be shortened by half. In addition, if the present invention can also be applied to external physical excitations such as knocking, vibration, and sound waves, the test rate will be greatly improved because after the MEMS resonator starts to vibrate, the present invention can complete the measurement of the Q value and the natural resonance frequency within dozens of milliseconds.

[0047] Compared with the existing measurement schemes for attenuation curves, the present invention not only greatly reduces the sampling frequency. Taking a gyroscope with 20KHz as an example, the sampling frequency can be reduced from 800KHz to 500Hz to avoid excessive requirements on the hardware circuit, but also simplifies the algorithm a lot. It is no longer necessary to fit complex functions, and only a few simple addition, subtraction, multiplication, division, and one square root operation are needed to complete, and high measurement accuracy can be guaranteed.

[0048] The detection scheme in the present invention measures the attenuation curve of the MEMS resonator 1 after the excitation is withdrawn to obtain the natural resonance frequency F0 and the quality factor Q. The difference from the related schemes in the prior art is that the present invention measures the integral value of multiple resonance periods (usually set to dozens to hundreds of resonance periods), and this integral value is closely related to the quality factor Q. For example, taking every 40 resonance periods as a unit, integral sampling is performed to obtain the average value of the output signal within multiple periods, and then the attenuation trend of the output signal per unit time is obtained.

[0049] According to another aspect of the present invention, the present invention provides a detection method for a MEMS resonator. Figure 4 It is a schematic flowchart of the detection method 400 for a MEMS resonator in an embodiment of the present invention. As Figure 4 shown, the detection method 400 includes the following operations.

[0050] Step 401, after exciting the MEMS resonator, withdraw the excitation so that the MEMS resonator enters the resonance state.

[0051] In one embodiment, the drive circuit 2 is used to provide the excitation to the MEMS resonator 1. In another embodiment, the excitation is provided to the MEMS resonator 1 by an external physical method. After the excitation is withdrawn, the MEMS resonator automatically returns to the natural resonance frequency F0.

[0052] Step 402: The charge amplifier 3 converts the induction signals of the first induction capacitor 10 and the second induction capacitor 11 into a resonant induction signal 12. One end of the first induction capacitor is coupled to the first end of the MEMS resonator, and one end of the second induction capacitor is coupled to the second end of the MEMS resonator. The first input terminal of the charge amplifier is coupled to the other end of the first induction capacitor, and the second input terminal of the charge amplifier is coupled to the other end of the second induction capacitor. The output terminal of the charge amplifier outputs the resonant induction signal.

[0053] Specifically, the vibration of the MEMS resonator causes a differential change in the capacitance values of the first induction capacitor and the second induction capacitor. The resonant induction signal is a voltage signal, which can reflect the resonant state of the MEMS resonator.

[0054] Step 403: Flip or cut off the negative part in the resonant induction signal 12 to obtain a rectified resonant induction signal 13.

[0055] In one embodiment, a full-wave rectifier is used to flip the negative part in the resonant induction signal 12 to a positive value to obtain a rectified resonant induction signal 13. In another embodiment, a half-wave rectifier is used to cut off the negative part in the resonant induction signal 12 to obtain a rectified resonant induction signal 13.

[0056] Step 404: Integrate the rectified resonant induction signal with a set integration time as a period.

[0057] In one embodiment, the set integration time is greater than or equal to 10 times the resonant period of the MEMS resonator.

[0058] Step 405: Sample the resonant integration signal output by the integrator to obtain an integration sampling value.

[0059] Step 406: Perform analog-to-digital conversion on the integration sampling value.

[0060] Step 408: The comparator compares the rectified resonant induction signal 13 with a predetermined threshold voltage to obtain a digital square wave signal.

[0061] Step 409: Count with the predetermined transition edge of the digital square wave signal as a trigger signal, and the count value per unit time is denoted as N1. In one embodiment, the predetermined transition is a rising edge. When the trigger signal is a rising edge, its count value is incremented by 1 until the end of the unit time t_unit to obtain the count value N1.

[0062] Step 410: Calculate the natural resonance frequency F0 of the MEMS resonator based on the count value N1 and the unit time. In one embodiment, when the negative part in the resonance induction signal is flipped, F0 = N1 / (2*t_unit). In another embodiment, when the negative part in the resonance induction signal is truncated, F0 = N1 / t_unit.

[0063] Step 411: Calculate the quality factor Q based on the natural resonance frequency F0 and the integral sampling values.

[0064] Specifically, the quality factor Q is calculated according to the following formula:

[0065]

[0066] where ω = 2πF0, v i is the i-th integral sampling value, i is greater than or equal to 2 and less than or equal to n, n is the number of integral sampling values, v1 is the first integral sampling value, and t _int is the set integral time.

[0067] For other parts of the detection method that are not described in detail, please refer to the relevant description of the detection circuit. Since the principles of the two are the same, they will not be elaborated here.

[0068] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0069] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Those of ordinary skill in the art can make changes, modifications, and variations to the above embodiments within the scope of the present invention.

Claims

1. A detection circuit for a MEMS resonator, characterized in that, It includes: A MEMS resonator is excited and then the excitation is removed so that the MEMS resonator enters a resonant state; A first sensing capacitor, one end of which is coupled to the first end of the MEMS resonator; A second sensing capacitor, one end of which is coupled to the second end of the MEMS resonator; A charge amplifier, wherein a first input terminal is coupled to the other end of the first sensing capacitor, a second input terminal is coupled to the other end of the second sensing capacitor, and an output terminal outputs a resonant sensing signal; A rectifier, whose input end is coupled to the output end of the charge amplifier, and is used to flip or cut off the negative value part of the resonant induction signal to obtain a rectified resonant induction signal; an integrator configured to integrate the rectified resonant induction signal with a set integration time as a period; a sampling circuit configured to sample the resonant integrated signal output by the integrator to obtain an integrated sampling value; a comparator, which is used to compare the rectified resonant induction signal with a predetermined threshold voltage to obtain a digital square wave signal; A counter, which uses the predetermined transition edge of the digital square wave signal as a trigger signal to count, and the count value per unit time t_unit is recorded as N1; A processing unit is used to calculate the natural resonant frequency F0 of the MEMS resonator according to the count value N1 and the unit time, and to calculate the quality factor Q according to the natural resonant frequency F0 and the integrated sampling value. In the case where the negative value part of the resonant induction signal is flipped, F0=N1 / (2*t_unit); or, in the case where the negative value part of the resonant induction signal is cut off, F0=N1 / t_unit, The quality factor Q is calculated according to the following formula: Among them , is the th integral sampling value, greater than or equal to 2 and less than or equal to n, where n is the number of integral sampling values, is the 1st integral sampling value, is the set integral time.

2. The detection circuit for a MEMS resonator according to claim 1, characterized in that, It also includes: a driving circuit, the driving circuit provides the excitation to the MEMS resonator and then removes the excitation; or provides the excitation to the MEMS resonator through an external physical method, After the excitation is removed, the MEMS resonator recovers to the natural resonant frequency F0 by itself.

3. The detection circuit for a MEMS resonator according to claim 1, characterized in that, The vibration of the MEMS resonator may cause a differential change in the capacitance values ​​of the first sensing capacitor and the second sensing capacitor. The resonance sensing signal is a voltage signal, which can reflect the resonance state of the MEMS resonator. The rectifier is a full-wave rectifier, and the full-wave rectifier flips the negative value part of the resonant induction signal into a positive value to obtain a rectified resonant induction signal, or, The rectifier is a half-wave rectifier, which cuts off the negative value part of the resonant induction signal to obtain a rectified resonant induction signal.

4. The detection circuit for a MEMS resonator according to claim 1, characterized in that, The set integration time is greater than or equal to 10 times the natural resonance period of the MEMS resonator. It also includes an analog-to-digital converter, which performs analog-to-digital conversion on the integrated sampling value obtained by the sampling circuit, and the processing unit performs processing based on the integrated sampling value after the analog-to-digital conversion.

5. The detection circuit for a MEMS resonator according to claim 1, characterized in that, The predetermined jump is a rising edge, and when the trigger signal is a rising edge, the count value of the counter is increased by 1 until the unit time t_unit ends to obtain the count value N1.

6. A detection method for a MEMS resonator, characterized in that, It includes: After exciting the MEMS resonator, the excitation is removed so that the MEMS resonator enters a resonant state; A charge amplifier converts the induced signals of a first induction capacitor and a second induction capacitor into a resonant induction signal, where one end of the first induction capacitor is coupled to the first end of the MEMS resonator, one end of the second induction capacitor is coupled to the second end of the MEMS resonator, the first input terminal of the charge amplifier is coupled to the other end of the first induction capacitor, the second input terminal of the charge amplifier is coupled to the other end of the second induction capacitor, and the output terminal of the charge amplifier outputs the resonant induction signal; Invert or cut off the negative value part in the resonant induction signal to obtain a rectified resonant induction signal; Integrate the rectified resonant induction signal with a set integration time as a period; Sample the resonant integration signal output by the sampling integrator to obtain an integration sampling value; A comparator compares the rectified resonant induction signal with a predetermined threshold voltage to obtain a digital square wave signal; Use the predetermined transition edge of the digital square wave signal as a trigger signal for counting, and the count value per unit time is denoted as N1; Calculate the natural resonant frequency F0 of the MEMS resonator according to the count value N1 and the unit time t_unit, and calculate the quality factor Q according to the natural resonant frequency F0 and the integration sampling value, When the negative value part in the resonant induction signal is inverted, F0 = N1 / (2*t_unit); or when the negative value part in the resonant induction signal is cut off, F0 = N1 / t_unit, The quality factor Q is calculated according to the following formula: Among them , is the th integral sampling value, greater than or equal to 2 and less than or equal to n, where n is the number of integral sampling values, is the 1st integral sampling value, is the set integral time.

7. The detection method of the MEMS resonator according to claim 6, wherein, The excitation of the MEMS resonator includes: Using a drive circuit to provide the excitation to the MEMS resonator, or Providing excitation to the MEMS resonator through an external physical method, After the excitation is withdrawn, the MEMS resonator automatically returns to the natural resonant frequency F0.

8. The detection method of the MEMS resonator according to claim 6, wherein, The vibration of the MEMS resonator causes a differential change in the capacitance values of the first induction capacitor and the second induction capacitor. The resonant induction signal is a voltage signal, which can reflect the resonant state of the MEMS resonator, Using a full-wave rectifier to invert the negative value part in the resonant induction signal into a positive value to obtain a rectified resonant induction signal, or Using a half-wave rectifier to cut off the negative value part in the resonant induction signal to obtain a rectified resonant induction signal.

9. The detection method of the MEMS resonator according to claim 6, wherein, The set integration time is greater than or equal to 10 times the natural resonant period of the MEMS resonator, The detection method further includes: performing analog-to-digital conversion on the integration sampling value obtained by the sampling circuit.

10. The detection method of the MEMS resonator according to claim 6, wherein, The predetermined transition is a rising edge. When the trigger signal is a rising edge, its count value is incremented by 1 until the unit time t_unit ends to obtain the count value N1.

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