Oscillation circuit loop analysis method based on physical characteristics of crystal oscillator

Abstract

The invention provides an oscillation circuit loop analysis method based on physical characteristics of a crystal oscillator, which is applied to the technical field of electronic measurement and is used for effectively inhibiting common-mode environmental interference by synchronously acquiring a crystal oscillator signal and an environmental interference signal and utilizing circuit differential operation so as to obtain a differential signal mainly comprising the crystal oscillator signal. Spectral analysis is carried out on the differential signals, actual performance parameters of the crystal oscillator are extracted, and noise is evaluated at the same time. And according to the noise evaluation result, adaptively adjusting the calibration performance parameters of the crystal oscillator to obtain a performance parameter threshold value which better accords with the current environmental noise level. And comparing the actual performance parameter with the adjusted performance parameter threshold, and judging whether the oscillation circuit loop of the crystal oscillator meets the production requirement or not. Therefore, on the premise that the production cost is low, the detection efficiency and the delivery quality of the high-precision electronic measuring instrument are effectively improved.

Description

Technical Field

[0001] This application relates to the field of electronic measurement technologies, and particularly to an analysis method for an oscillation circuit loop based on the physical characteristics of a crystal oscillator. Background Art

[0002] In the manufacturing process of high-precision electronic measurement instruments, the crystal oscillator serves as the core frequency reference of the instrument, and the quality of its performance is directly related to the measurement accuracy of the instrument. To ensure that each instrument leaving the factory can meet the predetermined accuracy standards, it is necessary to strictly analyze and detect the oscillation circuit loop of the crystal oscillator. Especially in the context of mass production, this kind of analysis and detection needs to be completed quickly and efficiently on the production line, while also avoiding any form of damage to the crystal oscillator and the instrument it is in.

[0003] However, the actual production line environment is often full of various adverse factors. Electromagnetic interference is widespread, and environmental temperature, humidity, etc. may also fluctuate. These factors will all affect the performance of the crystal oscillator, thereby reducing the accuracy of the analysis results. To adapt to the production rhythm, the analysis process must be highly automated, the operation should be as simple as possible, and it is best to be seamlessly integrated into the existing production line test system to reduce manual operation and dependence on additional equipment. In addition, considering the characteristics of mass production, cost-effectiveness is also a crucial consideration. On the premise of ensuring the analysis accuracy, how to minimize the cost and time of a single analysis has become an urgent problem to be solved.

[0004] Currently, there are still many challenges in the non-destructive and fast oscillation circuit loop analysis method for crystal oscillators in high-precision electronic measurement instruments on the production line. How to effectively overcome the influence of environmental noise in a complex production line environment, design a method that can ensure the analysis accuracy and meet the calibration requirements of high-precision instruments, while taking into account the requirements of rapid detection on the production line, being easy to integrate into the existing automated test system, and controlling the cost of new equipment and operation complexity within an acceptable range is the key to effectively improving the ex-factory quality and reliability of high-precision electronic measurement instruments without significantly increasing the production cost.

[0005] In view of the above problems, the existing technologies urgently need to be improved. Summary of the Invention

[0006] In view of the deficiencies of the above-mentioned existing technologies, this application provides an analysis method for an oscillation circuit loop based on the physical characteristics of a crystal oscillator, which has the beneficial effect of improving the accuracy of the analysis of the oscillation circuit loop of the crystal oscillator.

[0007] In a first aspect, an analysis method for an oscillation circuit loop based on the physical characteristics of a crystal oscillator, the method includes the steps: S1: Obtain the crystal oscillator signal and the environmental interference signal; S2: Perform circuit differential operation on the crystal oscillator signal and the environmental interference signal to obtain a differential signal; S3: Perform spectrum analysis on the differential signal, extract the actual performance parameters of the crystal oscillator, and obtain a noise evaluation result; S4: Obtain the calibrated performance parameters of the crystal oscillator, and adaptively adjust the calibrated performance parameters according to the noise evaluation result to obtain an adjusted performance parameter threshold; S5: Compare the actual performance parameters with the performance parameter threshold to determine whether the oscillation circuit loop of the crystal oscillator meets the production requirements, and output a judgment result.

[0008] An oscillation circuit loop analysis method based on the physical characteristics of a crystal oscillator proposed in this application aims to solve the influence of environmental interference on the accuracy of the analysis result. First, in step S1, the crystal oscillator signal and the environmental interference signal are synchronously collected to provide a signal basis for subsequent differential operations. In step S2, circuit differential operation is used to effectively suppress the common-mode environmental interference and obtain a differential signal mainly containing the crystal oscillator signal. In step S3, spectrum analysis is performed on the differential signal to extract the actual performance parameters of the crystal oscillator and evaluate the noise simultaneously, providing noise information for subsequent parameter threshold adjustment. In step S4, according to the noise evaluation result, the calibrated performance parameters of the crystal oscillator are adaptively adjusted to obtain a performance parameter threshold that better conforms to the current environmental noise level. In step S5, the actual performance parameters are compared with the adjusted performance parameter threshold to determine whether the oscillation circuit loop of the crystal oscillator meets the production requirements. Through the above steps, this technical solution uses differential operation to reduce environmental interference and adaptively adjusts the performance parameter threshold based on the noise evaluation result, thereby achieving accurate analysis of the oscillation circuit loop of the crystal oscillator under environmental interference.

[0009] Further, in step S4, the noise evaluation result includes the noise type and the noise intensity corresponding to different noise types; step S4 includes: S41: Obtain the calibrated performance parameters of the crystal oscillator and establish a mapping relationship model between the calibrated performance parameters of the crystal oscillator and environmental noise; S42: Calculate the performance parameter threshold of the crystal oscillator under the current noise type and noise intensity according to the mapping relationship model.

[0010] An oscillation circuit loop analysis method based on the physical characteristics of a crystal oscillator proposed in this application. By clarifying the specific content of the noise evaluation result and introducing a mapping relationship model, this application provides a more refined and adaptive method for adjusting performance parameter thresholds. This method can dynamically adjust the performance parameter thresholds according to the actual environmental noise situation, making the subsequent performance parameter judgment more accurate and reliable, solving the problem that the adaptive adjustment strategy is not specific enough, and improving the accuracy and environmental adaptability of the crystal oscillator oscillation circuit loop analysis method. The establishment of the mapping relationship model enables the adjustment of performance parameter thresholds to no longer be a simple fixed value, but to be dynamically adjusted according to the noise environment, thus more accurately reflecting the performance requirements of the crystal oscillator in the actual noise environment.

[0011] Further, step S41 includes: S411: Obtain the frequency, amplitude, and phase of the crystal oscillator in a noise-free experimental environment as the calibrated performance parameters; S412: Collect the historical environmental interference signals of the production line, and divide the historical environmental interference signals into multiple noise types and the noise intensities corresponding to different noise types; S413: Obtain the experimental performance parameters of the crystal oscillator corresponding to different noise types in the experimental environment; S414: Calculate the drift differences in frequency, amplitude, and phase between the experimental performance parameters and the calibrated performance parameters respectively, determine the influence coefficients of different noise types and noise intensities on the calibrated performance parameters according to the drift differences, and establish the mapping relationship model according to the influence coefficients.

[0012] An oscillation circuit loop analysis method based on the physical characteristics of a crystal oscillator proposed in this application. This technical solution provides a complete set of data collection, analysis, and modeling methods, realizes the specific construction of the mapping relationship model, makes it possible to adaptively adjust the performance parameter thresholds according to the actual noise environment, and improves the practicability and accuracy of the crystal oscillator oscillation circuit loop analysis method in a complex production line environment. Step S411 obtains the benchmark, steps S412 and S413 obtain the performance data under the noise environment, and step S414 establishes a mapping model for quantifying the noise impact. Each step provides the necessary technical support for finally achieving accurate performance evaluation.

[0013] Further, in step S414, the mapping relationship model is: , where is the adjusted frequency threshold, is the adjusted amplitude threshold, is the adjusted phase threshold, and the performance parameter thresholds include , , ; Among them, , , respectively represent the frequency, amplitude, and phase of the calibration performance parameters; Among them, , , are the influence coefficient of frequency, the influence coefficient of amplitude, and the influence coefficient of phase; , is the drift difference of frequency, is the noise intensity; , is the drift difference of amplitude; , is the drift difference of phase; is the serial number of the noise type, corresponding to the noise type, is the serial number of the noise intensity, corresponding to the noise intensity; is the current noise intensity.

[0014] An oscillation circuit loop analysis method based on the physical characteristics of a crystal oscillator proposed in this application. This solution concretizes the abstract "mapping relationship model" into a directly applicable mathematical formula, making it possible to adaptively adjust the performance parameter threshold based on the noise evaluation result. Through this model, the judgment criteria of performance parameters can be dynamically adjusted according to the actual noise environment, thereby improving the accuracy and reliability of the oscillation circuit loop analysis of the crystal oscillator. Especially in scenarios with complex noise environments such as production lines, it can more effectively screen out crystal oscillators that meet the production requirements. The form of the linear model also ensures the simplicity and real-time nature of the calculation, which is beneficial to the application of the fast production line.

[0015] Further, step S1 includes: S11: Through the first induction coil and the second induction coil, respectively, non-contact induction is performed on the original induction signal and the original environmental interference signal of the crystal oscillator; S12: Perform signal amplification and signal filtering on the original induction signal to obtain the processed crystal oscillator signal; S13: According to the sampling frequency and sampling time of the original induction signal, adjust the sampling frequency and sampling time of the original environmental interference signal so that the adjusted original environmental interference signal is aligned with the processed crystal oscillator signal in the time domain to obtain the synchronized environmental interference signal.

[0016] Further, step S2 includes: S21: Construct a differential amplifier circuit model. The differential amplifier circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is used to input the crystal oscillator signal, and the second input terminal is used to input the environmental interference signal; S22: Perform zero calibration on the crystal oscillator signal and the environmental interference signal output after passing through the differential amplifier circuit, eliminate the DC offset introduced by the non-ideal characteristics of circuit components, and obtain the differential signal.

[0017] Further, step S22 includes: S221: Obtain the initial DC offset voltage value at the output terminal of the differential amplifier circuit; S222: Construct a zero calibration circuit. The zero calibration circuit includes a digital-to-analog converter (DAC) and an adder. The output terminal of the DAC is connected to the third input terminal of the adder, and the fourth input terminal of the adder is connected to the output terminal of the differential amplifier circuit; S223: Generate a calibration compensation voltage through the DAC according to the initial DC offset voltage value; S224: Input the calibration compensation voltage into the third input terminal, and superimpose it on the crystal oscillator signal and the environmental interference signal output by the differential amplifier circuit to eliminate the initial DC offset voltage value and obtain the differential signal.

[0018] Further, step S3 includes: S31: Perform a fast Fourier transform on the differential signal to obtain spectral data, determine the noise type according to the frequency distribution reflected by the spectral data, and the noise intensity corresponding to the noise type; S32: Perform noise suppression processing on the noise type, remove the periodic noise, random noise, and impulse noise in the noise type, and obtain the differential signal after noise suppression processing; S33: Perform spectral analysis on the differential signal after noise suppression processing, and extract the frequency, amplitude, and phase parameters of the crystal oscillator as actual performance parameters; S34: Use the noise type and the noise intensity corresponding to the noise type as the noise evaluation result.

[0019] Further, step S5 includes: S51: Obtain the allowable error range window; S52: Compare the actual performance parameter with the performance parameter threshold, and determine whether the difference between the actual performance parameter and the performance parameter threshold is within the allowable error range window. If so, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements, and output the judgment result.

[0020] Further, step S52 includes: S521: Obtain the actual frequency, actual amplitude, and actual phase according to the actual performance parameter; obtain the frequency threshold, amplitude threshold, and phase threshold according to the performance parameter threshold; S522: Determine whether the difference between the actual frequency and the frequency threshold is within the allowable error range window. If so, determine that the frequency of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S523: Determine whether the difference between the actual amplitude and the amplitude threshold is within the allowable error range window. If so, determine that the amplitude of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S524: Determine whether the difference between the actual phase and the phase threshold is within the allowable error range window. If so, determine that the phase of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S525: If the frequency, amplitude, and phase of the crystal oscillator all meet the production requirements, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements, and display the qualified judgment result through an indicator light; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements, and give an unqualified judgment result through a buzzer alarm.

[0021] Beneficial effects: An oscillation circuit loop analysis method based on the physical characteristics of a crystal oscillator proposed in this application provides a signal basis for subsequent differential operations by synchronously collecting crystal oscillator signals and environmental interference signals. Using circuit differential operations, it effectively suppresses common-mode environmental interference and obtains a differential signal mainly containing crystal oscillator signals. Conducting spectral analysis on the differential signal to extract the actual performance parameters of the crystal oscillator and simultaneously evaluate the noise, providing noise information for subsequent parameter threshold adjustment. According to the noise evaluation results, adaptively adjust the calibrated performance parameters of the crystal oscillator to obtain a performance parameter threshold that better conforms to the current environmental noise level. Comparing the actual performance parameters with the adjusted performance parameter threshold to determine whether the oscillation circuit loop of the crystal oscillator meets the production requirements. Through the above steps, this technical solution uses differential operations to reduce environmental interference and adaptively adjusts the performance parameter threshold based on the noise evaluation results, thereby achieving accurate analysis of the oscillation circuit loop of the crystal oscillator under environmental interference. Therefore, this application has the beneficial effect of effectively improving the detection efficiency and ex-factory quality of high-precision electronic measuring instruments on the premise of production cost. Description of the Drawings

[0022] Figure 1 It is a flowchart of an oscillation circuit loop analysis method based on the physical characteristics of a crystal oscillator proposed in this application.

[0023] Figure 2 It is a schematic structural diagram of a differential amplifier circuit model proposed in this application. Detailed Embodiments

[0024] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and marked in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided in the drawings below is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0025] It should be noted that: Similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, terms such as "first, second" are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0026] Currently, in the prior art, there is a lack of a non-destructive and fast oscillation circuit loop analysis method for crystal oscillators in high-precision electronic measuring instruments on the production line. To solve this problem, the present application proposes an oscillation circuit loop analysis method based on the physical characteristics of crystal oscillators, which is as follows: Please refer to Figure 1 , in the first aspect, an oscillation circuit loop analysis method based on the physical characteristics of crystal oscillators, the method includes the steps of: S1: Obtain the crystal oscillator signal and the environmental interference signal; S2: Perform circuit differential operation on the crystal oscillator signal and the environmental interference signal to obtain a differential signal; S3: Perform spectrum analysis on the differential signal to extract the actual performance parameters of the crystal oscillator and obtain a noise evaluation result; S4: Obtain the calibrated performance parameters of the crystal oscillator, and adaptively adjust the calibrated performance parameters according to the noise evaluation result to obtain an adjusted performance parameter threshold; S5: Compare the actual performance parameters with the performance parameter threshold to determine whether the oscillation circuit loop of the crystal oscillator meets the production requirements, and output a judgment result.

[0027] Among them, in step S1, the acquisition of the crystal oscillator signal and the environmental interference signal can be performed synchronously to eliminate environmental interference for subsequent differential operation. The signal acquisition method can be non-contact induction, using an induction coil to approach the crystal oscillator and the environmental noise source to capture the signals respectively. In step S2, the circuit differential operation is implemented by a differential amplifier circuit. This circuit receives the crystal oscillator signal and the environmental interference signal as inputs, realizes signal subtraction through the circuit structure, and the environmental interference is suppressed as a common-mode signal, and a differential signal is output.

[0028] In step S3, the spectrum analysis is implemented by methods such as fast Fourier transform. The differential signal is converted to the frequency domain, and the actual performance parameters such as the frequency, amplitude, and phase of the crystal oscillator are analyzed. The noise evaluation result can include the noise type and the noise intensity. The noise type can be determined according to the spectrum distribution characteristics, and the noise intensity can be reflected by the spectrum amplitude.

[0029] In step S4, the calibrated performance parameters are the performance parameters of the crystal oscillator measured in advance in a noise-free ideal environment. The adaptive adjustment process is carried out according to the noise evaluation result obtained in step S3. For different noise types and intensities, the calibrated performance parameters are adjusted to obtain a performance parameter threshold suitable for the current environment. The adjustment method can establish a mapping relationship model between the calibrated performance parameters and the noise parameters. The model can be a function or a look-up table.

[0030] In step S5, the actual performance parameters are compared with the adjusted performance parameter thresholds. The comparison items may include parameters such as frequency, amplitude, and phase. The comparison result is used to determine whether the oscillation circuit of the crystal oscillator meets the production requirements. The judgment criterion may be whether the difference between the actual performance parameters and the performance parameter thresholds is within the allowable error range. The judgment result is output in the form of a signal, such as a qualified or unqualified indication. Through the above steps, accurate analysis of the oscillation circuit of the crystal oscillator can be achieved under environmental interference.

[0031] In some specific embodiments, on the production line of electronic instruments, in order to analyze the performance of the oscillation circuit of the crystal oscillator in the instrument, a non-contact induction coil is used to synchronously collect the crystal oscillator signal and the production line environmental interference signal. The induction coil is close to the crystal oscillator and the production line noise source, and the original signals are respectively induced. After the original signals are preprocessed by signal amplification and filtering, they are input into the differential amplifier circuit. The differential amplifier circuit is built with an operational amplifier having a high common-mode rejection ratio. The preprocessed crystal oscillator signal and the environmental interference signal are input into the non-inverting input terminal and the inverting input terminal of the differential amplifier circuit for differential operation, and a differential signal is output. After the differential signal is sampled by an analog-to-digital converter, spectrum analysis is performed using the fast Fourier transform to obtain spectrum data. According to the spectrum data, the noise type and intensity are analyzed. For example, the noise frequency is judged by the position of the spectrum peak, and the noise intensity is determined by the peak amplitude. At the same time, the actual performance parameters such as the frequency, amplitude, and phase of the crystal oscillator are extracted from the spectrum data. The calibrated frequency, calibrated amplitude, and calibrated phase of the crystal oscillator are measured in a noise-free environment in advance as the calibrated performance parameters. A mapping relationship between the calibrated performance parameters and the noise intensity is established. For example, a linear mapping relationship. When the noise intensity increases, the frequency threshold, amplitude threshold, and phase threshold are adjusted according to a certain ratio. According to the actual noise intensity, the adjusted frequency threshold, amplitude threshold, and phase threshold are calculated using the mapping relationship model. The actual frequency, actual amplitude, and actual phase are respectively compared with the adjusted frequency threshold, amplitude threshold, and phase threshold to determine whether the difference is within the preset error range. If the frequency, amplitude, and phase are all within the error range, it is determined that the oscillation circuit of the crystal oscillator is qualified; otherwise, it is determined to be unqualified. The qualified result is displayed by a green indicator light, and the unqualified result is prompted by a red indicator light and a buzzer alarm.

[0032] Further, in step S4, the noise evaluation result includes the noise type and the noise intensity corresponding to different noise types; step S4 includes: S41: Obtain the calibrated performance parameters of the crystal oscillator and establish a mapping relationship model between the calibrated performance parameters of the crystal oscillator and the environmental noise; S42: According to the mapping relationship model, calculate the performance parameter thresholds of the crystal oscillator under the current noise type and noise intensity.

[0033] Among them, in step S41, the method for obtaining the calibration performance parameters is as follows: in an ideal experimental environment without noise, measure the frequency, amplitude, and phase of the crystal oscillator, and use the measurement results as the calibration performance parameters. The process of establishing the mapping relationship model of environmental noise is as follows: First, collect the historical environmental interference signals of the production line, and divide the historical environmental interference signals into multiple noise types and the corresponding noise intensity levels of different noise types. For example, the noise types can include electromagnetic interference, mechanical vibration, etc., and the noise intensity levels can be divided into level one, level two, and level three. Then, in a controllable experimental environment, simulate various noise types and intensities on the production line, and measure the experimental performance parameters of the crystal oscillator under different noise conditions. The experimental performance parameters also include frequency, amplitude, and phase. By comparing the experimental performance parameters with the calibration performance parameters, calculate the drift differences of the frequency, amplitude, and phase of the crystal oscillator under different noise types and intensities. The drift differences reflect the influence degree of noise on the performance parameters of the crystal oscillator. Based on these drift differences, determine the influence coefficients of different noise types and noise intensities on the calibration performance parameters. The influence coefficient can be understood as the quantitative influence degree of noise on the performance parameters. Finally, establish a mapping relationship model between the calibration performance parameters and environmental noise according to the influence coefficients. The mapping relationship model can be a mathematical formula, a look-up table, or other forms of models, which is used to describe how the calibration performance parameters should be adjusted to obtain reasonable performance parameter thresholds under a given noise type and intensity.

[0034] In step S42, the calculation process of the performance parameter threshold is as follows: when the noise evaluation result in the actual production line environment determines the current noise type and noise intensity, according to the mapping relationship model established in step S41, use the current noise type and noise intensity as the input, and the result output by the model is the performance parameter threshold under the current noise environment. The performance parameter thresholds include frequency threshold, amplitude threshold, and phase threshold. These thresholds are the adaptive adjustment results of the calibration performance parameters after considering the influence of environmental noise, and can more accurately reflect the performance requirements of the crystal oscillator in the actual noise environment.

[0035] Furthermore, step S41 includes: S411: Obtain the frequency, amplitude, and phase of the crystal oscillator in a noise-free experimental environment as the calibration performance parameters; S412: Collect the historical environmental interference signals of the production line, and divide the historical environmental interference signals into multiple noise types and the corresponding noise intensities of different noise types; S413: Obtain the experimental performance parameters of the crystal oscillator corresponding to different noise types in the experimental environment; S414: Calculate the drift differences in frequency, amplitude, and phase between the experimental performance parameters and the calibrated performance parameters respectively. Determine the influence coefficients of different noise types and noise intensities on the calibrated performance parameters based on the drift differences, and establish a mapping relationship model according to the influence coefficients.

[0036] Among them, in step S411, the acquisition of the calibrated performance parameters can be completed in a noise-free experimental environment such as a shielded room. The frequency, amplitude, and phase parameters of the crystal oscillator are measured by a precision spectrum analyzer, and these measured values are recorded as the reference calibrated performance parameters for subsequent performance evaluation and comparison.

[0037] In step S412, the acquisition of the historical environmental interference signals on the production line is realized by deploying various environmental signal acquisition devices such as electromagnetic field probes and vibration sensors on the production line. The collected signals are analyzed by a signal processing unit. For example, methods such as fast Fourier transform are used to identify the main noise types, such as electromagnetic interference, mechanical vibration noise, power supply ripple noise, etc. For each noise type, the noise intensity is quantified by statistical analysis methods. For example, parameters such as the root mean square value and power spectral density of the noise signal are calculated, and the noise intensity is divided into multiple levels, such as level one, level two, and level three.

[0038] In step S413, the acquisition of the experimental performance parameters is carried out in a controllable experimental environment. The experimental environment needs to be able to simulate various noise types and intensities on the production line. For example, electromagnetic interference is simulated by a signal generator, and mechanical vibration noise is simulated by a vibration table. Under each noise type and intensity, the frequency, amplitude, and phase parameters of the crystal oscillator are measured again by a spectrum analyzer, and these measured values are recorded as the experimental performance parameters.

[0039] In step S414, the calculation of the drift difference is achieved by comparing the experimental performance parameters obtained in step S413 with the calibrated performance parameters obtained in step S411. For frequency, the drift difference is the frequency value in the experimental environment minus the frequency value in the noise-free environment. The amplitude drift difference and phase drift difference are calculated in a similar way. The determination of the influence coefficient is based on the drift difference and the noise intensity. For example, the frequency influence coefficient can be obtained by dividing the frequency drift difference by the noise intensity, which characterizes the frequency drift amount caused by unit noise intensity. Based on these influence coefficients, a quantitative relationship between the calibrated performance parameters and the noise type and noise intensity is established.

[0040] Furthermore, in step S414, the mapping relationship model is: , where is the adjusted frequency threshold, is the adjusted amplitude threshold, is the adjusted phase threshold, and the performance parameter thresholds include , , ; Among them, , , respectively represent the frequency, amplitude, and phase for calibrating the performance parameters; Among them, , , are the influence coefficients of frequency, amplitude influence coefficient, and phase influence coefficient; , is the drift difference of frequency, is the noise intensity; , is the drift difference of amplitude; , is the drift difference of phase; is the serial number of the noise type, corresponding to the noise type, is the serial number of the noise intensity, corresponding to the noise intensity; is the current noise intensity.

[0041] Among them, the establishment and application process of the mapping relationship model are explained in detail. The model targets the three key performance parameters of frequency, amplitude, and phase, and uses a linear relationship for adjustment. The adjusted frequency threshold is obtained by subtracting the product of the frequency influence coefficient, frequency drift difference, and current noise intensity from the calibrated frequency threshold. The adjustment methods for the amplitude threshold and phase threshold are similar, both using a linear adjustment model.

[0042] Specifically, to establish the mapping relationship model, it is first necessary to experimentally obtain the drift differences of the frequency, amplitude, and phase of the crystal oscillator under different noise types and intensities in advance. The experimental process includes obtaining the calibrated performance parameters of the crystal oscillator in a noise-free environment, and collecting the experimental performance parameters of the crystal oscillator under different noise types and intensities. By comparing the experimental performance parameters with the calibrated performance parameters, the frequency drift difference, amplitude drift difference, and phase drift difference can be calculated. Then, based on these drift differences, the frequency influence coefficient, amplitude influence coefficient, and phase influence coefficient are calculated. These influence coefficients reflect the degree of influence of a specific noise type and intensity on the performance parameters. The calculation of the influence coefficients can be obtained by analyzing the relationship between the drift difference and the noise intensity through linear regression or other statistical analysis methods.

[0043] In practical applications, when the noise type and intensity in the production line environment are detected, the mapping relationship model can be applied. By substituting the detected noise type and intensity into the mapping relationship model and combining the pre-calculated influence coefficient and drift difference, the adjusted frequency threshold, amplitude threshold, and phase threshold can be quickly calculated. These adjusted thresholds will be used as the basis for judging whether the performance of the crystal oscillator meets the production requirements in the subsequent steps.

[0044] Further, step S1 includes: S11: Induct the original induction signal and the original environmental interference signal of the crystal oscillator in a non-contact manner through the first induction coil and the second induction coil respectively; S12: Perform signal amplification and signal filtering on the original induction signal to obtain the processed crystal oscillator signal; S13: Adjust the sampling frequency and sampling time of the original environmental interference signal according to the sampling frequency and sampling time of the original induction signal, so that the adjusted original environmental interference signal is aligned with the processed crystal oscillator signal in the time domain to obtain the synchronized environmental interference signal.

[0045] Among them, in step S11, the first induction coil is placed close to the crystal oscillator to induct the electromagnetic signal generated by the crystal oscillator, and the second induction coil is placed far from the crystal oscillator but still in the same environmental interference to specifically induct the environmental interference signal. The induction coil can be an air-core coil or a magnetic-core coil, and the number of turns and size of the coil can be adjusted according to the intensity of the actual induction signal.

[0046] In step S12, a low-noise amplifier can be used for signal amplification to increase the amplitude of the original induction signal so that the subsequent signal processing circuit can effectively process it. A band-pass filter can be used for signal filtering to filter out the noise outside the frequency band of the original induction signal, such as high-frequency noise and low-frequency drift.

[0047] In step S13, the sampling frequency and sampling time of the original induction signal are preset by the signal acquisition system, and the sampling frequency and sampling time of the environmental interference signal need to be adjusted according to the sampling parameters of the crystal oscillator signal. The adjustment method can be to adjust the clock frequency or sampling interval of the environmental interference signal acquisition system to align the sampling points of the environmental interference signal with the sampling points of the crystal oscillator signal on the time axis.

[0048] Specifically, the first induction coil and the second induction coil are used to collect the original induction signal and the environmental interference signal of the crystal oscillator in a non-contact manner, avoiding the influence on the working state of the crystal oscillator caused by direct contact and ensuring the authenticity of signal collection. The original induction signal is processed by signal amplification, and the signal intensity is increased, which is beneficial to the effective processing of the subsequent circuit. Through signal filtering, the noise in the original induction signal is filtered out, and the signal quality is improved. Further, by adjusting the sampling frequency and sampling time of the environmental interference signal, the synchronization alignment of the environmental interference signal and the crystal oscillator signal in the time domain is achieved, laying a foundation for effectively eliminating environmental interference in the subsequent differential operation, and finally realizing the non-contact, high-quality and synchronous acquisition of the crystal oscillator signal and the environmental interference signal.

[0049] Further, step S2 includes: S21: Construct a differential amplifier circuit model. The differential amplifier circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is used to input the crystal oscillator signal, and the second input terminal is used to input the environmental interference signal; S22: Perform zero calibration on the crystal oscillator signal and the environmental interference signal output after passing through the differential amplifier circuit to eliminate the DC offset introduced by the non-ideal characteristics of the circuit components, and obtain a differential signal.

[0050] Among them, the purpose of constructing the differential amplifier circuit is to initially reduce the influence of the environmental interference signal on the crystal oscillator signal by utilizing the characteristic of the differential amplifier circuit to suppress common-mode interference. Specifically, the differential amplifier circuit can be built using an operational amplifier, such as a low-noise operational amplifier with the model number OPA2134. The first input terminal and the second input terminal can be respectively connected to the first induction coil and the second induction coil, and the first induction coil and the second induction coil are used to pick up the crystal oscillator signal and the environmental interference signal in a non-contact manner.

[0051] To achieve zero-point calibration, a zero-point calibration circuit can be designed. The zero-point calibration circuit may include a digital-to-analog converter (DAC), such as a DAC8568 digital-to-analog converter, and an adder, which can be implemented using another operational amplifier, such as a precision operational amplifier of model OPA2333. The output terminal of the digital-to-analog converter (DAC) is connected to the third input terminal of the adder, and the output terminal of the differential amplification circuit is connected to the fourth input terminal of the adder. By controlling the calibration compensation voltage output by the digital-to-analog converter (DAC), the DC offset at the output terminal of the differential amplification circuit can be cancelled. The value of the calibration compensation voltage can be determined according to the initial DC offset voltage value, and the initial DC offset voltage value can be measured by a high-precision voltmeter. The zero-point calibration process can be iteratively performed until the DC offset is sufficiently eliminated. Thus, the subsequent spectral analysis of the differential signal can more accurately reflect the actual performance parameters of the crystal oscillator, improving the accuracy and reliability of the analysis results.

[0052] Further, step S22 includes: S221: Obtain the initial DC offset voltage value at the output terminal of the differential amplification circuit; S222: Construct a zero-point calibration circuit, which includes a digital-to-analog converter (DAC) and an adder. The output terminal of the digital-to-analog converter (DAC) is connected to the third input terminal of the adder, and the fourth input terminal of the adder is connected to the output terminal of the differential amplification circuit; S223: Generate a calibration compensation voltage through the digital-to-analog converter (DAC) according to the initial DC offset voltage value; S224: Input the calibration compensation voltage into the third input terminal to be superimposed with the crystal oscillator signal and the environmental interference signal output by the differential amplification circuit to cancel the initial DC offset voltage value and obtain a differential signal.

[0053] Specifically, please refer to Figure 2 , the specific process of constructing the differential amplification circuit model is as follows: The main function of the differential amplification circuit is to receive the crystal oscillator signal and the environmental interference signal and output their differential signal. The differential amplification structure is as follows: It includes: a first input terminal (Vin1) for receiving the crystal oscillator signal; a second input terminal (Vin2) for receiving the environmental interference signal; The output terminal (Vout) of the differential amplification circuit is used to output the differential signal; The output of the differential amplification circuit can be expressed as: Vout = Ad(Vin1 - Vin2), where Ad is the differential gain, representing the amplification multiple of the circuit for the differential signal.

[0054] Set up a zero-point calibration circuit, whose main function is to eliminate the DC offset introduced by the non-ideal characteristics of circuit components. The zero-point calibration circuit structure is as follows: Set the adder input terminals: The third input terminal (Vcomp) is used to receive the calibration compensation voltage generated by the digital-to-analog converter (DAC); The fourth input terminal (Vdiff) is used to receive the output signal of the differential amplifier circuit.

[0055] The output terminal of the zero-point calibration circuit (Vout_final) is used to output the calibrated differential signal; The output of the zero-point calibration circuit can be expressed as: Vout_final = Vdiff + Vcomp.

[0056] Among them, the function of the digital-to-analog converter (DAC) is to generate the calibration compensation voltage according to the initial DC offset voltage value. The specific steps are as follows: Measure the initial DC offset voltage value Voffset at the output terminal of the differential amplifier circuit; According to Voffset, generate the calibration compensation voltage Vcomp through the DAC, such that: Vcomp = −Voffset.

[0057] The function of the adder is to superimpose the calibration compensation voltage and the output signal of the differential amplifier circuit to eliminate the DC offset. The addition can be expressed as: Vout_final = Vdiff + Vcomp.

[0058] In summary, the complete differential circuit model can be expressed as: Differential amplifier circuit: Vdiff = Ad(Vin1 − Vin2); 2. Zero-point calibration circuit: Obtain the initial DC offset voltage value Voffset; Generate the calibration compensation voltage Vcomp = −Voffset through the DAC. Adder output: Vout_final = Vdiff + Vcomp.

[0059] Furthermore, step S3 includes: S31: Perform a fast Fourier transform on the differential signal to obtain spectral data, determine the noise type according to the frequency distribution reflected by the spectral data, and the noise intensity corresponding to the noise type; S32: Perform noise suppression processing on the noise type, remove the periodic noise, random noise, and impulse noise in the noise type to obtain the differential signal after noise suppression processing; S33: Perform spectral analysis on the differential signal after noise suppression processing, and extract the frequency, amplitude, and phase parameters of the crystal oscillator as the actual performance parameters; S34: Use the noise type and the noise intensity corresponding to the noise type as the noise evaluation result.

[0060] Among them, in step S31, the fast Fourier transform is used to transform the differential signal in the time domain into the frequency domain, thereby obtaining spectral data. In the spectral data, different types of noise exhibit different frequency distribution characteristics in the frequency domain. For example, periodic noise usually appears as discrete frequency peaks on the spectrum, random noise appears as an uplift of the broadband noise floor on the spectrum, and impulse noise may cause an increase in transient broadband energy on the spectrum. By analyzing the frequency distribution of the spectral data, the existing noise types can be identified, and the noise intensity can be evaluated according to the energy size of the noise components in the spectral data. For example, the intensity of periodic noise can be characterized by the amplitude of the frequency peak, the intensity of random noise can be characterized by the average energy level of the noise floor, and the intensity of impulse noise can be characterized by the size of the transient energy peak.

[0061] In step S32, for the noise types determined in step S31, corresponding noise suppression processing methods are adopted. For periodic noise, a notch filter or an adaptive filter can be used for filtering. The notch filter is configured to have high attenuation at the frequency points of the periodic noise, thereby removing the periodic noise components. The adaptive filter can be adaptively adjusted according to the characteristics of the periodic noise to achieve more accurate noise filtering. For random noise, a Wiener filter or a Kalman filter can be used for suppression. The Wiener filter performs optimal filtering based on the statistical characteristics of the noise and the signal to minimize the noise components in the output signal. The Kalman filter can use the state space model of the signal and the noise for filtering to achieve effective suppression of random noise. For impulse noise, a median filter or a wavelet threshold denoising method can be used for processing. The median filter can effectively suppress pulse-type impulse noise while retaining the edge information of the signal. The wavelet threshold denoising method can separate the impulse noise from the signal through wavelet transform and set a threshold to remove the noise components.

[0062] In step S33, the differential signal after noise suppression processing is subjected to spectral analysis again. The purpose is to extract more accurate crystal oscillator performance parameters. Since the noise has been effectively suppressed, the spectral analysis result will be less affected by noise interference. Therefore, the frequency, amplitude, and phase parameters of the crystal oscillator can be extracted more accurately. As actual performance parameters, these parameters will more truly reflect the performance of the crystal oscillator in the actual working environment.

[0063] In step S34, the noise types determined in step S31 and the evaluated noise intensity are output as the noise evaluation result. This noise evaluation result can be used to adaptively adjust the calibrated performance parameters in subsequent step S4 to provide quantitative information about the noise environment.

[0064] Further, step S5 includes: S51: Obtain an allowable error range window; S52: Compare the actual performance parameter with the performance parameter threshold, and determine whether the difference between the actual performance parameter and the performance parameter threshold is within the allowable error range window. If so, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements, and output the judgment result.

[0065] Among them, obtaining the allowable error range window means determining the acceptable deviation range of a performance parameter, which can be specifically implemented in the following ways: A fixed error range value can be preset. For example, the allowable frequency deviation is ±10 ppm, the allowable amplitude deviation is ±5%, and the allowable phase deviation is ±2°. Or, the size of the error range window can be dynamically adjusted according to the specific model, application scenario or production requirements of the crystal oscillator. For example, for crystal oscillators with high-precision requirements, a smaller error range window is set, and vice versa. Or, a reasonable error range window can be determined through experimental data or statistical analysis methods. For example, collect the performance parameter data of a batch of qualified crystal oscillators, analyze their deviation distribution, and set the deviation range covering most qualified products as the allowable error range window.

[0066] Among them, comparing the actual performance parameter with the performance parameter threshold, and determining whether the difference between the actual performance parameter and the performance parameter threshold is within the allowable error range window. If so, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements, and output the judgment result means comparing the actually measured performance parameter of the crystal oscillator with the set performance parameter threshold, and considering the allowable error range. Specifically, first calculate the difference between the actual performance parameter and the performance parameter threshold, and this difference can be an absolute value or a relative value. Then, determine whether this difference falls within the preset allowable error range window. If the difference is within the error range window, it is considered that the performance of the crystal oscillator meets the production requirements and is determined to be qualified; otherwise, if the difference exceeds the error range window, it is considered that the performance of the crystal oscillator does not meet the production requirements, is determined to be unqualified, and the judgment result is output, such as displaying "qualified" or "unqualified" information through a display screen, or indicating the judgment result through a signal indicator.

[0067] Thus, by introducing the allowable error range window, the judgment standard for the performance of the crystal oscillator changes from absolute compliance to relative compliance, which is more in line with the actual production situation, avoids misjudgment caused by minor deviations, and improves the accuracy and practicality of the judgment. Step S51 provides the basis for judgment for step S52. Based on step S51, step S52 performs specific comparison and judgment operations, and the two work together to achieve precise evaluation of the performance of the crystal oscillator.

[0068] Further, step S52 includes: S521: Obtain the actual frequency, actual amplitude, and actual phase according to the actual performance parameters; obtain the frequency threshold, amplitude threshold, and phase threshold according to the performance parameter thresholds; S522: Determine whether the difference between the actual frequency and the frequency threshold is within the allowable error range window. If so, determine that the frequency of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S523: Determine whether the difference between the actual amplitude and the amplitude threshold is within the allowable error range window. If so, determine that the amplitude of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S524: Determine whether the difference between the actual phase and the phase threshold is within the allowable error range window. If so, determine that the phase of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S525: If the frequency, amplitude, and phase of the crystal oscillator all meet the production requirements, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements, and display the qualified determination result through an indicator light; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements, and give an alarm prompt for the unqualified determination result through a buzzer.

[0069] Among them, this solution refines the performance judgment process of the oscillation circuit loop of the crystal oscillator. The actual performance parameters and performance parameter thresholds are decomposed into three groups of parameter pairs: the actual frequency and the frequency threshold, the actual amplitude and the amplitude threshold, and the actual phase and the phase threshold. For each group of parameter pairs, a judgment is made on whether the difference is within the allowable error range window to determine whether the frequency, amplitude, and phase respectively meet the production requirements. Only when the frequency, amplitude, and phase all meet the production requirements can it be finally determined that the oscillation circuit loop of the crystal oscillator is qualified as a whole. The indicator light is used to display the qualified result, and the buzzer is used to give an alarm prompt for the unqualified result, making the determination result more intuitive.

[0070] In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0071] The above description is only for the embodiments of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator, characterized in that The method includes the steps of: S1: Obtain a crystal oscillator signal and an environmental interference signal; S2: Perform a circuit differential operation on the crystal oscillator signal and the environmental interference signal to obtain a differential signal; S3: Perform a spectrum analysis on the differential signal, extract the actual performance parameters of the crystal oscillator, and obtain a noise evaluation result; S4: Obtain the calibrated performance parameters of the crystal oscillator, adaptively adjust the calibrated performance parameters according to the noise evaluation result to obtain an adjusted performance parameter threshold; S5: Compare the actual performance parameters with the performance parameter threshold to determine whether the oscillation circuit loop of the crystal oscillator meets the production requirements, and output a judgment result.

2. The analysis method of an oscillation circuit loop based on the physical characteristics of a crystal oscillator according to claim 1, wherein In step S4, the noise evaluation result includes a noise type and a noise intensity corresponding to different noise types; step S4 includes: S41: Obtain the calibrated performance parameters of the crystal oscillator and establish a mapping relationship model between the calibrated performance parameters of the crystal oscillator and environmental noise; S42: Calculate the performance parameter threshold of the crystal oscillator under the current noise type and noise intensity according to the mapping relationship model.

3. The analysis method of an oscillation circuit loop based on the physical characteristics of a crystal oscillator according to claim 2, wherein Step S41 includes: S411: Obtain the frequency, amplitude, and phase of the crystal oscillator in a noise-free experimental environment as the calibrated performance parameters; S412: Collect historical environmental interference signals on the production line and divide the historical environmental interference signals into multiple noise types and noise intensities corresponding to different noise types; S413: Obtain the experimental performance parameters of the crystal oscillator under different noise types in the experimental environment; S414: Calculate the drift differences in frequency, amplitude, and phase between the experimental performance parameters and the calibrated performance parameters respectively, determine the influence coefficients of different noise types and noise intensities on the calibrated performance parameters according to the drift differences, and establish the mapping relationship model according to the influence coefficients.

4. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator according to claim 3, characterized in that In step S414, the mapping relationship model is: , where is the adjusted frequency threshold is the adjusted amplitude threshold is the adjusted phase threshold, and the performance parameter threshold includes , , ; Among them, , , respectively represent the frequency, amplitude and phase of the calibrated performance parameter; Among them, , , are the frequency influence coefficient, amplitude influence coefficient, and phase influence coefficient; , is the drift difference of the frequency, is the noise intensity; , is the drift difference of the amplitude; , is the drift difference of the phase; is the serial number of the noise type, corresponding to the noise type, is the serial number of the noise intensity, corresponding to the noise intensity; is the current noise intensity.

5. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator according to claim 1, characterized in that, Step S1 includes: S11: Induce the original induction signal of the crystal oscillator and the original environmental interference signal in a non-contact manner through a first induction coil and a second induction coil respectively; S12: Perform signal amplification and signal filtering on the original induction signal to obtain the processed crystal oscillator signal; S13: Adjust the sampling frequency and sampling time of the original environmental interference signal according to the sampling frequency and sampling time of the original induction signal, so that the adjusted original environmental interference signal is aligned with the processed crystal oscillator signal in the time domain to obtain the synchronized environmental interference signal.

6. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator, as claimed in claim 1, wherein Step S2 includes: S21: Construct a differential amplifier circuit model. The differential amplifier circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is used to input the crystal oscillator signal, and the second input terminal is used to input the environmental interference signal; S22: Perform zero calibration on the crystal oscillator signal and the environmental interference signal output after passing through the differential amplifier circuit to eliminate the DC offset introduced by the non-ideal characteristics of circuit components, and obtain the differential signal.

7. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator, as claimed in claim 6, wherein Step S22 includes: S221: Obtain the initial DC offset voltage value at the output end of the differential amplifier circuit; S222: Construct a zero calibration circuit, where the zero calibration circuit includes a digital-to-analog converter (DAC) and an adder. The output end of the DAC is connected to the third input end of the adder, and the fourth input end of the adder is connected to the output end of the differential amplifier circuit; S223: Generate a calibration compensation voltage through the DAC according to the initial DC offset voltage value; S224: Input the calibration compensation voltage into the third input end and superimpose it with the crystal oscillator signal and the environmental interference signal output by the differential amplifier circuit to eliminate the initial DC offset voltage value and obtain the differential signal.

8. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator, as claimed in claim 1, wherein Step S3 includes: S31: Perform a fast Fourier transform on the differential signal to obtain spectral data, determine the noise type according to the frequency distribution reflected by the spectral data, and the noise intensity corresponding to the noise type; S32: Perform noise suppression processing on the noise type, remove the periodic noise, random noise, and impulse noise in the noise type, and obtain the differential signal after noise suppression processing; S33: Perform spectral analysis on the differential signal after noise suppression processing, and extract the frequency, amplitude, and phase parameters of the crystal oscillator as actual performance parameters; S34: Use the noise type and the noise intensity corresponding to the noise type as the noise evaluation result.

9. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator, as claimed in claim 1, wherein Step S5 includes: S51: Obtain the allowable error range window; S52: Compare the actual performance parameters with the performance parameter threshold, and determine whether the difference between the actual performance parameters and the performance parameter threshold is within the allowable error range window. If so, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements and output the judgment result.

10. A method for analyzing an oscillation circuit loop based on the physical characteristics of a crystal oscillator, as claimed in claim 9, wherein Step S52 includes: S521: Obtain the actual frequency, actual amplitude, and actual phase according to the actual performance parameters; obtain the frequency threshold, amplitude threshold, and phase threshold according to the performance parameter threshold; S522: Determine whether the difference between the actual frequency and the frequency threshold is within the allowable error range window. If so, determine that the frequency of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S523: Determine whether the difference between the actual amplitude and the amplitude threshold is within the allowable error range window. If so, determine that the amplitude of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements; S524: Determine whether the difference between the actual phase and the phase threshold is within the allowable error range window. If so, determine that the phase of the crystal oscillator meets the production requirements; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements. S525: If the frequency, amplitude, and phase of the crystal oscillator all meet the production requirements, determine that the oscillation circuit loop of the crystal oscillator meets the production requirements, and display the qualified determination result through the indicator light; otherwise, determine that the oscillation circuit loop of the crystal oscillator does not meet the production requirements, and give an unqualified determination result through the buzzer alarm.

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