A warm-up crystal oscillator aging compensation method and system

Abstract

This application discloses a method and system for compensating for the aging of a temperature-compensated crystal oscillator. During the calibration phase, the frequency error of the crystal oscillator is measured, and digital compensation parameters are generated and stored in a non-volatile memory. During operation, when the device is powered on, these parameters are read, and a compensation voltage is generated and applied to the crystal oscillator in a single operation, thus compensating for aging and initial deviations. This application's solution creatively proposes a simplified "calibration-storage-application" process. Through the non-obvious simplification of "one-time power-on compensation," it simultaneously achieves high precision, low cost, low power consumption, and ease of implementation. It exhibits strong stability and a simple structure, achieving long-term stability approaching that of complex dynamic systems through a "one-time" static compensation.

Description

Technical Field

[0001] This invention relates to the field of navigation receiver technology, specifically to a method and system for compensating for aging of a temperature-compensated crystal oscillator. Background Technology

[0002] Global Navigation Satellite Systems (GNSS), as a crucial national space infrastructure, provide positioning, navigation, and timing (PNT) services that are widely applied in key sectors such as transportation, energy, communications, and the military. Currently, four major global navigation systems have emerged: BeiDou (BDS), GPS, GLONASS, and Galileo. Among them, the BeiDou-3 system has achieved global networking, covering over 200 countries and regions worldwide, becoming a core supporting technology for safeguarding national economy, people's livelihoods, and national security.

[0003] The BeiDou-3 satellite navigation system is a global satellite navigation system independently developed by my country. Its anti-jamming antenna array receiver suppresses interference signals in the spatial, time, and frequency domains, thereby achieving high-precision and high-reliability positioning, navigation, and timing services in complex electromagnetic environments. In such receivers, the performance of the radio frequency front-end module is crucial, as it provides the local oscillation signal required for down-conversion and analog-to-digital conversion of the entire system.

[0004] The Temperature Compensated Crystal Oscillator (TCXO) is the core clock source in the RF front-end module. Its frequency stability directly determines the receiver's signal acquisition and tracking performance, as well as the accuracy of digital processing algorithms such as beamforming. Although the TCXO compensates for frequency drift caused by temperature changes through its internal circuitry, its output frequency will still drift slowly and unidirectionally over time, a phenomenon known as "aging." For high-precision applications such as BeiDou-3, the annual aging rate of the TCXO (e.g., ±0.5ppm to ±2.0ppm) will generate a significant cumulative frequency error after several years of operation, thereby degrading the overall performance of the receiver.

[0005] Existing TCXO aging compensation schemes mainly suffer from the following two types of problems:

[0006] The first type is based on manually adjusting the voltage divider resistors or potentiometers. This type of solution not only has low compensation accuracy, but its most fatal flaw is that the compensation state can change due to mechanical vibration or temperature cycling, which introduces new instabilities. Moreover, it must be manually adjusted by disassembling the device, which cannot meet the long-term use requirements of anti-interference receivers in harsh environments such as vehicle-mounted and ship-mounted systems.

[0007] The second category is based on complex real-time measurement and feedback systems. For example, a field-programmable gate array (FPGA) is used to monitor the frequency in real time and drive a digital-to-analog converter (DAC) to form a closed loop. While this type of solution offers high accuracy, it is complex, consumes a lot of power, and is very expensive. Applying it to multi-channel antenna array receivers (typically requiring 8-16 channels) would multiply the system size, cost, and power consumption, making it impractical for engineering applications.

[0008] Therefore, there is an urgent need for a solution that can achieve a fundamental balance between compensation accuracy, structural complexity, long-term stability, cost, and power consumption. Summary of the Invention

[0009] The purpose of this invention is to provide a method and system for compensating for aging of temperature-compensated crystal oscillators, so as to solve the problems of complex structure, difficulty in ensuring compensation accuracy, and poor stability of existing related solutions.

[0010] To achieve the above objectives, embodiments of this application provide a method for compensating for aging in a temperature-compensated crystal oscillator, comprising:

[0011] Based on the aging rate of the temperature-compensated crystal oscillator (TCXO) and the preset equipment lifespan, the total compensation required for the entire lifespan of the TCXO is calculated and allocated to the compensation value for each set time period.

[0012] The composite compensation parameters are calculated by combining the inherent frequency deviation of the temperature-compensated crystal oscillator with the compensation value for each set time.

[0013] When the equipment is running, it acquires the composite compensation parameters for the set time period corresponding to the current time, generates a simulated compensation voltage based on the composite compensation parameters, and applies it to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

[0014] The total compensation amount is averaged or allocated to the compensation value for each set time period according to the aging prediction model; the aging prediction model is generated based on the annual aging rate, design life and aging curve characteristics of the temperature-compensated crystal oscillator.

[0015] The entire lifecycle of the temperature-compensated crystal oscillator is divided into several time periods as needed. The length of each time period may be equal or unequal. Each set time period corresponds to a compensation value and a corresponding composite compensation parameter.

[0016] When the equipment is running, the microcontroller obtains the composite compensation parameters for the corresponding set time period based on the current time point to perform aging compensation.

[0017] The composite compensation parameter is a composite compensation code obtained by summing the inherent frequency deviation value of the temperature-compensated crystal oscillator and the corresponding digital-to-analog converter (DAC) code for each set time compensation value;

[0018] Write the composite compensation code into the memory;

[0019] When the device is running, it retrieves the composite compensation code for the set time period corresponding to the current time from the memory, generates an analog compensation voltage, and applies it to the frequency control terminal of the temperature-compensated crystal oscillator in one go to complete the compensation for aging and initial deviation.

[0020] An internal or external real-time clock (RTC) records the device's runtime.

[0021] A preset time threshold is set. When the running time reaches the preset time threshold, the composite compensation parameters corresponding to the next preset time period are obtained to generate a simulated compensation voltage, which is applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation; or

[0022] When the equipment is running, it records its own power-on working time or the number of temperature cycles it experiences;

[0023] When the cumulative value of the power-on working time or the number of temperature cycles reaches a preset threshold, the composite compensation parameters corresponding to the current set time period are obtained to generate a simulated compensation voltage, which is applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation; or

[0024] Triggered by calibration instructions from the main processor, the composite compensation parameters corresponding to the currently set time period are obtained to generate a simulated compensation voltage, which is then applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete aging compensation; or

[0025] A compensation data table based on the accelerated aging test data of the temperature-compensated crystal oscillator is pre-stored in a non-volatile memory; the compensation data table contains multiple time points and corresponding composite compensation parameters;

[0026] When the equipment is running, based on the real-time accumulated running time, the analog compensation voltage is dynamically calculated and updated by looking up the compensation data table or by interpolation, and then applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

[0027] The compensation value is the initial compensation value C0 and the set periodic aging coefficient K;

[0028] During equipment operation, the initial compensation value C0 and the set cycle aging coefficient K are obtained in each set cycle, and the composite compensation parameters are calculated; or

[0029] The composite compensation parameters are set as a two-dimensional lookup table, with one dimension being the cumulative working time and the other dimension being the working temperature range;

[0030] During equipment operation, the operating time and real-time temperature are simultaneously queried, and the optimal composite compensation parameters are calculated using bilinear interpolation; or

[0031] Frequency error data of the temperature-compensated crystal oscillator is collected periodically. The aging trend is learned and predicted through an embedded machine learning model. The updated prediction model parameters are then fused with the inherent frequency deviation value of the temperature-compensated crystal oscillator and the compensation value at each set time to obtain composite compensation parameters.

[0032] When the device is running, after obtaining the composite compensation parameters, it performs a cyclic redundancy check; if the check fails, the built-in default safety value is used.

[0033] Monitor the power supply voltage; if abnormal fluctuations in the power supply are detected, aging compensation should be suspended.

[0034] A TVS diode is connected in parallel to ground at the frequency control voltage pin of the temperature-compensated crystal oscillator.

[0035] On the other hand, this application provides a temperature-compensated crystal oscillator aging compensation system, comprising:

[0036] The compensation voltage generation unit is used to calculate the total compensation required for the entire life cycle of the temperature-compensated crystal oscillator (TCXO) based on the aging rate of the TCXO and the preset equipment lifespan, and allocate it to the compensation value for each set time period; and calculate the composite compensation parameter by combining the inherent frequency deviation value of the TCXO and the compensation value for each set time period.

[0037] A control and storage unit, including a microprocessor and non-volatile memory, is used to control and store the composite compensation parameters;

[0038] A digital-to-analog conversion unit, electrically connected to the control and storage unit, is used to perform digital-to-analog conversion;

[0039] A voltage buffer unit, electrically connected to the digital-to-analog converter unit, is used to output a stable, low-impedance compensation voltage.

[0040] The system is configured to: call the composite compensation parameters generated by the compensation voltage generation unit and stored in the non-volatile memory through the control and storage unit, and after passing through the digital-to-analog conversion unit and the voltage buffer unit, provide the compensation voltage to the external temperature-compensated crystal oscillator to complete the aging compensation.

[0041] The compensation voltage generation unit is implemented using a non-volatile digital potentiometer;

[0042] The voltage buffer unit is a voltage follower composed of an operational amplifier;

[0043] The digital-to-analog converter unit is integrated inside the microprocessor; or

[0044] The digital-to-analog converter unit is composed of a microprocessor's DAC / PWM output pin connected to a second-order low-pass filter circuit; or

[0045] The digital-to-analog conversion unit uses an independent digital-to-analog conversion chip and communicates with the microprocessor via an SPI interface.

[0046] Between the digital-to-analog converter unit and the voltage buffer unit, there is a first-order RC low-pass filter circuit with a cutoff frequency set below 1kHz to suppress high-frequency noise at the output of the digital-to-analog converter.

[0047] The method and system provided in this application perform high-precision calibration at the factory and store digital parameters in memory. Each time the device is powered on, these parameters are automatically read and applied to complete the compensation. The compensation parameters are not simple initial deviation corrections, but rather a composite value of "initial frequency deviation" and "estimated long-term aging drift." A system consisting of a "control and storage unit + compensation voltage generation unit + voltage buffer unit" is provided. A voltage follower is used to provide low-impedance output, and an RC low-pass filter is set to suppress high-frequency noise from the DAC / PWM, ensuring that a clean and stable DC voltage is applied to the TCXO. This application's solution creatively proposes a simplified "calibration-storage-application" process. Through the non-obvious simplification of "one-time power-on compensation," it simultaneously achieves high precision, low cost, low power consumption, and ease of implementation. It exhibits strong stability and a simple structure, achieving long-term stability approaching that of complex dynamic systems through "one-time" static compensation. Attached Figure Description

[0048] Figure 1 A schematic diagram of a BeiDou-3 anti-interference receiver system for the application of the scheme provided in the embodiments of this application;

[0049] Figure 2 A flowchart illustrating the principle of the temperature-compensated crystal oscillator aging compensation method provided in this application embodiment;

[0050] Figure 3 A schematic diagram of a composite compensation parameter calculation model provided in an embodiment of this application;

[0051] Figure 4 An aging compensation circuit diagram for a temperature-compensated crystal oscillator is provided for an embodiment of this application;

[0052] Figure 5A schematic diagram of a specific aging compensation process is provided for an embodiment of this application;

[0053] Figure 6 This is a schematic diagram of the structure of the temperature-compensated crystal oscillator aging compensation system provided in an embodiment of this application. Detailed Implementation

[0054] To better understand the present invention, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Various modifications can be made to the embodiments as long as the effects of the present invention are achieved.

[0055] This application proposes an aging compensation method and system based on a temperature-compensated crystal oscillator (TCXO). It is applied to a BeiDou-3 anti-interference antenna array receiver system. The system includes an aging compensation module that communicates with the main processor / FPGA via a digital bus (such as I2C / SPI) and controls the TCXO in the RF front-end module via an analog compensation voltage line. The main processor / FPGA is responsible for running the anti-interference algorithm and baseband processing, and it requires a highly stable clock from the TCXO as a reference.

[0056] See details Figure 1 This is a schematic diagram of the BeiDou-3 anti-interference receiver system used in this application, which includes the temperature-compensated crystal oscillator aging compensation module proposed in this application. This aging compensation module includes the following structure:

[0057] Control and data storage unit: includes a microcontroller (MCU) and non-volatile memory; the microcontroller has a built-in digital-to-analog converter (DAC); the non-volatile memory is used to store digital codes corresponding to the TCXO aging compensation values;

[0058] Voltage output and buffer unit: includes an operational amplifier configured as a voltage follower to receive the analog voltage output from the built-in DAC and buffer the output to generate a stable, low-impedance compensation voltage.

[0059] Controlled TCXO: Its frequency control voltage terminal is connected to the output terminal of the voltage output and buffer unit, and receives the compensation voltage to correct its output frequency.

[0060] This application adopts a "one-time power-on compensation" technical approach, abandoning the traditional complex real-time, closed-loop compensation mode and creatively proposing a simplified "calibration-storage-application" process. High-precision calibration is performed at the factory, and digital parameters are stored in the memory. Each time the device is powered on, these parameters are automatically read and applied to complete the compensation.

[0061] When the microcontroller is powered on, it reads the digital code from the non-volatile memory and writes it into its built-in DAC, causing the DAC to output a corresponding compensation voltage. This voltage is then buffered and applied to the frequency control voltage terminal of the TCXO, thereby achieving one-time power-on compensation for the aging effect of the TCXO.

[0062] The microcontroller communicates with the non-volatile memory via an I2C bus or an SPI bus. Optionally, a low-pass filter circuit is provided between the output of the built-in DAC and the non-inverting input of the operational amplifier to filter out high-frequency noise in the DAC output signal.

[0063] Specifically, such as Figure 2 As shown, Figure 2 The flowchart of the temperature-compensated crystal oscillator aging compensation method provided in the embodiments of this application is shown, wherein,

[0064] Step 101: Based on the aging rate of the temperature-compensated crystal oscillator (TCXO) and the preset equipment lifespan, calculate the total compensation required for the entire lifespan of the TCXO and allocate it to the compensation value for each set time period.

[0065] In one embodiment of this application, such as Figure 3 The diagram shown is a schematic of a composite compensation parameter calculation model provided in an embodiment of this application, wherein...

[0066] Compensation value = Initial deviation compensation + Aging prediction compensation

[0067] Initial deviation compensation: Used to correct the inherent frequency deviation of the TCXO at the time of manufacture.

[0068] Aging prediction compensation: Based on the aging rate of TCXO (e.g. ±0.5ppm / year) and the preset equipment lifespan (e.g. 10 years), the total compensation required over the entire lifespan is calculated and averaged or distributed to the annual compensation value according to the aging curve model.

[0069] During the calibration phase, the corresponding DAC codes of the two components mentioned above can be summed to obtain the final composite compensation code written to memory. This method achieves full lifecycle frequency management of the TCXO "from birth to retirement," with effects far exceeding those of simpler schemes that only compensate for initial deviations.

[0070] Step 102: Combine the inherent frequency deviation of the temperature-compensated crystal oscillator with the compensation value for each set time to calculate the composite compensation parameter.

[0071] In one embodiment of this application, the total compensation amount is averaged or allocated to the compensation value for each set time period according to the aging prediction model; the aging prediction model is generated based on the annual aging rate, design life, and aging curve characteristics of the temperature-compensated crystal oscillator.

[0072] The entire lifecycle of the temperature-compensated crystal oscillator is divided into several time periods as needed. The length of each time period may be equal or unequal. Each set time period corresponds to a compensation value and a corresponding composite compensation parameter.

[0073] When the equipment is running, the microcontroller obtains the composite compensation parameters for the corresponding set time period based on the current time point to perform aging compensation.

[0074] Step 103: When the equipment is running, the composite compensation parameters for the set time period corresponding to the current time are obtained. Based on the composite compensation parameters, a simulated compensation voltage is generated and applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

[0075] In one embodiment of this application, the composite compensation parameter is a composite compensation code obtained by summing the inherent frequency deviation value of the temperature-compensated crystal oscillator and the digital-to-analog converter (DAC) code corresponding to the compensation value at each set time.

[0076] Write the composite compensation code into the memory;

[0077] When the device is running, it retrieves the composite compensation code for the set time period corresponding to the current time from the memory, generates an analog compensation voltage, and applies it to the frequency control terminal of the temperature-compensated crystal oscillator in one go to complete the compensation for aging and initial deviation.

[0078] In one embodiment of this application, an internal or external real-time clock (RTC) records the device's runtime.

[0079] A preset time threshold is set. When the running time reaches the preset time threshold, the composite compensation parameters corresponding to the next preset time period are obtained to generate a simulated compensation voltage, which is applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

[0080] In one embodiment of this application, the device records its own power-on working time or the number of temperature cycles it experiences during operation;

[0081] When the cumulative value of the power-on working time or the number of temperature cycles reached a preset threshold, the composite compensation parameters corresponding to the current set time period were obtained to generate a simulated compensation voltage, which was applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

[0082] In one embodiment of this application, a composite compensation parameter corresponding to the current set time period is obtained and a simulated compensation voltage is generated and applied to the frequency control terminal of the temperature-compensated crystal oscillator according to the calibration instruction from the main processor to complete the aging compensation.

[0083] In one embodiment of this application, a compensation data table based on the accelerated aging test data of the temperature-compensated crystal oscillator is pre-stored in a non-volatile memory; the compensation data table includes multiple time points and corresponding composite compensation parameters;

[0084] When the equipment is running, based on the real-time accumulated running time, the analog compensation voltage is dynamically calculated and updated by looking up the compensation data table or by interpolation, and then applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

[0085] In one embodiment of this application, the compensation value is an initial compensation value C0 and a set periodic aging coefficient K;

[0086] During equipment operation, the initial compensation value C0 and the set cycle aging coefficient K are obtained in each set cycle, and the composite compensation parameters are calculated.

[0087] In one embodiment of this application, the composite compensation parameter is set as a two-dimensional lookup table, with one dimension being the cumulative working time and the other dimension being the working temperature range;

[0088] During equipment operation, the working time and real-time temperature are queried simultaneously, and the optimal composite compensation parameters are obtained through bilinear interpolation.

[0089] In one embodiment of this application, frequency error data of a temperature-compensated crystal oscillator is collected periodically, and the aging trend is learned and predicted through an embedded machine learning model. The updated prediction model parameters are then fused with the inherent frequency deviation value of the temperature-compensated crystal oscillator and the compensation value at each set time to obtain composite compensation parameters.

[0090] In one embodiment of this application, when the device is running, after obtaining the composite compensation parameters, a cyclic redundancy check is performed; if the check fails, the built-in default security value is used.

[0091] Monitor the power supply voltage; if abnormal fluctuations in the power supply are detected, aging compensation should be suspended.

[0092] A TVS diode is connected in parallel to ground at the frequency control voltage pin of the temperature-compensated crystal oscillator.

[0093] Specifically, such as Figure 4 The diagram shown is an aging compensation circuit diagram of a temperature-compensated crystal oscillator provided in an embodiment of this application. Its core consists of three parts: a control and data storage unit (MCU and EEPROM), a digital-to-analog converter and voltage buffer unit (DAC and operational amplifier), and a controlled TCXO.

[0094] Before leaving the factory, the equipment undergoes calibration. The TCXO output frequency is measured using an external high-precision frequency meter, and the error is calculated. Assuming the measured frequency is 0.8 ppm too fast, and the TCXO sensitivity is +0.5 ppm / V, a negative compensation voltage ΔV = -(0.8 ppm) / (0.5 ppm / V) = -1.6V needs to be applied. If the TCXO tuning center voltage is 1.55V, then the target compensation voltage V_comp = 1.55V - 1.6V = -0.05V. Since the voltage cannot be negative, this example indicates that the initial frequency error is too large, exceeding the compensation range. Therefore, in actual calibration, a voltage is first output through the DAC to coarsely tune the TCXO frequency to a very small error range (e.g., ±0.1 ppm) near the nominal value. Then, the remaining error is measured, and the final fine-compensation DAC code is calculated and stored in the EEPROM. During normal operation, after the MCU powers on and initializes, it reads this code from the EEPROM and configures the DAC, thus automatically completing the compensation.

[0095] Algorithm and hardware stability design:

[0096] Data verification: After reading the compensation data from the EEPROM, the microcontroller performs a CRC-16 cyclic redundancy check. If the check fails, a built-in default safety value is used to ensure that the system can still start, although the accuracy is reduced.

[0097] Power supply monitoring: The MCU monitors the power supply voltage. If abnormal fluctuations in the power supply are detected, the DAC output update is paused to prevent voltage spikes from impacting the TCXO and causing frequency jumps.

[0098] ESD protection: A TVS diode is connected in parallel to ground at the frequency control voltage pin of the TCXO to absorb electrostatic pulses and protect the expensive TCXO device from damage.

[0099] like Figure 5 The diagram shown is a specific aging compensation process provided in an embodiment of this application.

[0100] Calibration phase:

[0101] S1: After the circuit board is manufactured, put the TCXO aging compensation circuit into calibration mode;

[0102] S2: Using a high-precision frequency reference source, measure the actual output frequency of the TCXO and calculate the error value between it and the nominal frequency;

[0103] S3: Calculate the required compensation voltage value based on the frequency error value and the voltage control sensitivity of the TCXO;

[0104] S4: Convert the compensation voltage value into the corresponding DAC digital code, and write the code into the non-volatile memory;

[0105] Operation phase:

[0106] S5: The device is powered on, and the microcontroller reads the DAC digital code from the non-volatile memory;

[0107] S6: The microcontroller writes the digital code into its built-in DAC, and the DAC outputs the corresponding compensation voltage;

[0108] S7: The compensation voltage, after being buffered by the voltage buffer unit, is applied to the frequency control voltage terminal of the TCXO to complete the frequency correction.

[0109] In one embodiment of this application, an ultra-low-power MCU based on the ARM Cortex-M3 core is selected, which integrates a 12-bit resolution DAC. The non-volatile memory is an EEPROM with a capacity of ≥128 bytes. The operational amplifier is a precision operational amplifier with low noise, low bias current, and low offset voltage. The TCXO is a high-stability temperature-compensated crystal oscillator with a frequency of 10MHz, a voltage-controlled sensitivity of ±0.5ppm / V, and a tuning voltage range of 0.5V to 2.5V.

[0110] The circuit works as follows: Before leaving the factory, the device is calibrated. The TCXO output frequency is measured using an external high-precision frequency meter, and the error is calculated. Assuming the measured frequency is 0.8 ppm too fast, and the TCXO sensitivity is +0.5 ppm / V, a negative compensation voltage ΔV = -(0.8 ppm) / (0.5 ppm / V) = -1.6V needs to be applied. If the TCXO tuning center voltage is 1.55V, then the target compensation voltage V_comp = 1.55V - 1.6V = -0.05V. Since the voltage cannot be negative, this example indicates that the initial frequency error is too large, exceeding the compensation range. Therefore, in actual calibration, a voltage is first output through the DAC to coarsely tune the TCXO frequency to a very small error range (e.g., ±0.1 ppm) near the nominal value. Then, the remaining error is measured, and the final fine-compensation DAC code is calculated and stored in the EEPROM. During normal device use, after the MCU powers on and initializes, it reads the code from the EEPROM and configures the DAC, thus automatically completing the compensation.

[0111] The entire solution is based on a complete temperature-compensated crystal oscillator aging compensation system, which is as follows: Figure 6 As shown, it includes:

[0112] The compensation voltage generation unit 21 is used to calculate the total compensation required for the entire life cycle of the temperature-compensated crystal oscillator (TCXO) based on the aging rate of the TCXO and the preset equipment lifespan, and allocate it to the compensation value for each set time period; and calculate the composite compensation parameter by combining the inherent frequency deviation value of the TCXO and the compensation value for each set time period.

[0113] The control and storage unit 22 includes a microprocessor and a non-volatile memory for controlling and storing the composite compensation parameters;

[0114] The digital-to-analog conversion unit 23 is electrically connected to the control and storage unit and is used to perform digital-to-analog conversion;

[0115] The voltage buffer unit 24 is electrically connected to the digital-to-analog converter unit and is used to output a stable, low-impedance compensation voltage.

[0116] The system is configured to: call the composite compensation parameters generated by the compensation voltage generation unit 21 and stored in the non-volatile memory through the control and storage unit 22, and after passing through the digital-to-analog conversion unit 23 and the voltage buffer unit 24, provide the compensation voltage to the external temperature-compensated crystal oscillator to complete the aging compensation.

[0117] The compensation voltage generation unit 21 is implemented using a non-volatile digital potentiometer;

[0118] The voltage buffer unit 24 is a voltage follower composed of an operational amplifier;

[0119] The digital-to-analog converter unit 23 is integrated inside the microprocessor; or

[0120] The digital-to-analog converter unit 23 is composed of a microprocessor's DAC / PWM output pin connected to a second-order low-pass filter circuit; or

[0121] The digital-to-analog converter unit 23 uses an independent digital-to-analog converter chip and communicates with the microprocessor through the SPI interface.

[0122] Between the digital-to-analog converter unit 23 and the voltage buffer unit 24, a first-order RC low-pass filter circuit is provided, with its cutoff frequency set below 1kHz, to suppress high-frequency noise at the output of the digital-to-analog converter. Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0123] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0124] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0125] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0126] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0127] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0128] Computer-readable media include both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0129] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0130] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0131] The above are merely embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0132] The accompanying drawings illustrate several block diagrams and / or flowcharts. It should be understood that some blocks, or combinations thereof, in the block diagrams and / or flowcharts can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when executed by the processor, these instructions can create means for implementing the functions / operations described in these block diagrams and / or flowcharts. The technology of this application can be implemented in hardware and / or software (including firmware, microcode, etc.). Alternatively, the technology of this application can take the form of a computer program product stored on a computer-readable storage medium, which can be used by or in conjunction with an instruction execution system.

Claims

1. A method for compensating aging in a temperature-compensated crystal oscillator, characterized in that, include: Based on the aging rate of the temperature-compensated crystal oscillator (TCXO) and the preset equipment lifespan, the total compensation required for the entire lifespan of the TCXO is calculated and allocated to the compensation value for each set time period. The composite compensation parameters are calculated by combining the inherent frequency deviation of the temperature-compensated crystal oscillator with the compensation value for each set time. When the equipment is running, it acquires the composite compensation parameters for the set time period corresponding to the current time, generates a simulated compensation voltage based on the composite compensation parameters, and applies it to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

2. The method according to claim 1, characterized in that, The total compensation amount is averaged or allocated to the compensation value for each set time period according to the aging prediction model; the aging prediction model is generated based on the annual aging rate, design life and aging curve characteristics of the temperature-compensated crystal oscillator.

3. The method according to claim 1, characterized in that, The method further includes: The entire lifecycle of the temperature-compensated crystal oscillator is divided into several time periods as needed. The length of each time period may be equal or unequal. Each set time period corresponds to a compensation value and a corresponding compensation parameter. When the equipment is running, the microcontroller obtains the composite compensation parameters for the corresponding set time period based on the current time point to perform aging compensation.

4. The method according to claim 1, characterized in that, The method further includes: The composite compensation parameter is a composite compensation code obtained by summing the inherent frequency deviation value of the temperature-compensated crystal oscillator and the corresponding digital-to-analog converter (DAC) code for each set time compensation value; Write the composite compensation code into the memory; When the device is running, it retrieves the composite compensation code for the set time period corresponding to the current time from the memory, generates an analog compensation voltage, and applies it to the frequency control terminal of the temperature-compensated crystal oscillator in one go to complete the compensation for aging and initial deviation.

5. The method according to claim 1, characterized in that, The method further includes: An internal or external real-time clock (RTC) records the device's runtime. A preset time threshold is set. When the running time reaches the preset time threshold, the composite compensation parameters corresponding to the next preset time period are obtained to generate a simulated compensation voltage, which is applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation; or When the equipment is running, it records its own power-on working time or the number of temperature cycles it experiences; When the cumulative value of the power-on working time or the number of temperature cycles reaches a preset threshold, the composite compensation parameters corresponding to the current set time period are obtained to generate a simulated compensation voltage, which is applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation; or Triggered by calibration instructions from the main processor, the composite compensation parameters corresponding to the currently set time period are obtained to generate a simulated compensation voltage, which is then applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete aging compensation; or A compensation data table based on the accelerated aging test data of the temperature-compensated crystal oscillator is pre-stored in a non-volatile memory; the compensation data table contains multiple time points and corresponding composite compensation parameters. When the equipment is running, based on the real-time accumulated running time, the analog compensation voltage is dynamically calculated and updated by looking up the compensation data table or by interpolation, and then applied to the frequency control terminal of the temperature-compensated crystal oscillator to complete the aging compensation.

6. The method according to claim 1, characterized in that, The method further includes: The compensation value is the initial compensation value C0 and the set periodic aging coefficient K; During equipment operation, the initial compensation value C0 and the set cycle aging coefficient K are obtained in each set cycle, and the composite compensation parameters are calculated; or The composite compensation parameters are set as a two-dimensional lookup table, with one dimension being the cumulative working time and the other dimension being the working temperature range; During equipment operation, the operating time and real-time temperature are simultaneously queried, and the optimal composite compensation parameters are calculated using bilinear interpolation; or Frequency error data of the temperature-compensated crystal oscillator is collected periodically. The aging trend is learned and predicted through an embedded machine learning model. The updated prediction model parameters are then fused with the inherent frequency deviation value of the temperature-compensated crystal oscillator and the compensation value at each set time to obtain composite compensation parameters.

7. The method according to claim 1, characterized in that, The method further includes: When the device is running, after obtaining the composite compensation parameters, it performs a cyclic redundancy check; if the check fails, the built-in default safety value is used. Monitor the power supply voltage; if abnormal fluctuations in the power supply are detected, aging compensation should be suspended. A TVS diode is connected in parallel to ground at the frequency control voltage pin of the temperature-compensated crystal oscillator.

8. An aging compensation system for a temperature-compensated crystal oscillator, characterized in that, include: The compensation voltage generation unit is used to calculate the total compensation required for the entire life cycle of the temperature-compensated crystal oscillator (TCXO) based on the aging rate of the TCXO and the preset equipment lifespan, and allocate it to the compensation value for each set time period; and calculate the composite compensation parameter by combining the inherent frequency deviation value of the TCXO and the compensation value for each set time period. A control and storage unit, including a microprocessor and non-volatile memory, is used to control and store the composite compensation parameters; A digital-to-analog conversion unit, electrically connected to the control and storage unit, is used to perform digital-to-analog conversion; A voltage buffer unit, electrically connected to the digital-to-analog converter unit, is used to output a stable, low-impedance compensation voltage. The system is configured to: call the composite compensation parameters generated by the compensation voltage generation unit and stored in the non-volatile memory through the control and storage unit, and after passing through the digital-to-analog conversion unit and the voltage buffer unit, provide the compensation voltage to the external temperature-compensated crystal oscillator to complete the aging compensation.

9. The system according to claim 8, characterized in that, The compensation voltage generation unit is implemented using a non-volatile digital potentiometer; The voltage buffer unit is a voltage follower composed of an operational amplifier; The digital-to-analog converter unit is integrated inside the microprocessor; or The digital-to-analog converter unit is composed of a microprocessor's DAC / PWM output pin connected to a second-order low-pass filter circuit; or The digital-to-analog conversion unit uses an independent digital-to-analog conversion chip and communicates with the microprocessor via an SPI interface.

10. The system according to claim 8, characterized in that, Between the digital-to-analog converter unit and the voltage buffer unit, there is a first-order RC low-pass filter circuit with a cutoff frequency set below 1kHz to suppress high-frequency noise at the output of the digital-to-analog converter.

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