JP6529788B2 - Oscillator - Google Patents

Description

  The present invention relates to an oscillator manufacturing method and an oscillator.

  The oscillator has an aging characteristic in which the oscillation frequency of the oscillation signal output by itself changes as time passes (see, for example, Patent Document 1).

JP, 2013-150157, A

  In the case of manufacturing an oscillator in which the change in oscillation frequency after aging is small, the process of measuring the change in oscillation frequency over time and sorting out non-defective products with a low change over time is performed. However, since the implementation period of this process is long, in the conventional method of manufacturing an oscillator, there has been a problem that the period from receiving an oscillator to shipping becomes long.

  Therefore, the present invention has been made in view of these points, and it is an object of the present invention to provide a method of manufacturing an oscillator and an oscillator which can suppress the secular change after shipment while shortening the period from order acceptance to shipment. To aim.

  A method of manufacturing an oscillator according to a first aspect of the present invention is a method of manufacturing an oscillator, in an external device electrically connected to the oscillator, the oscillation frequency of an oscillation signal output from the oscillator is set for a predetermined period. Measuring, and generating correction information to be used by the oscillator to correct aging of the oscillation frequency based on a change characteristic of the oscillation frequency in the predetermined period; and the correction generated in the external device Storing information in a storage unit provided in the oscillator.

  In the manufacturing method, the oscillator includes correction means for correcting the oscillation frequency based on an element different from the aging, and in the measuring step, the external device performs the correction means of the oscillator. The oscillation frequency of the oscillation signal output from the oscillator may be measured by stopping.

  The manufacturing method compares the step of acquiring the correction information stored in the storage unit in the external device, and the correction information generated in the step of generating the external device with the acquired correction information. The method may further include the step of determining whether the content of the acquired correction information is correct.

  In the manufacturing method, in the generating step, the external device may calculate, as the correction information, a value of a parameter included in an arithmetic expression used by the oscillator to correct the secular change of the oscillation frequency.

  An oscillator according to a second aspect of the present invention is an oscillator that corrects secular change of an oscillation frequency of an oscillation signal output by itself, and includes a measurement unit that measures the oscillation frequency over a predetermined period, and A generation unit that generates correction information that the oscillator uses to correct aging of the oscillation frequency based on change characteristics of the oscillation frequency, and storage control that stores the generated correction information in a storage unit provided in the oscillator A correction unit that corrects the oscillation frequency based on the correction information stored in the storage unit.

  ADVANTAGE OF THE INVENTION According to this invention, it is effective in the ability to suppress the secular change after shipment, shortening the period from order reception to shipment.

It is a figure which shows the structure of the oscillator which concerns on 1st Embodiment, and an external apparatus. It is a flowchart which concerns on correction | amendment of the aging of oscillation frequency. It is a figure which shows the secular change characteristic of the oscillation frequency which the measurement part measured. It is a sequence diagram which shows the flow of a parameter setting process. It is a figure which shows the secular change of the oscillation frequency after shipment of an oscillator. It is a figure showing the composition of the oscillator concerning a 2nd embodiment.

First Embodiment
[Overall overview]
FIG. 1 is a view showing configurations of an oscillator 1 and an external device 2 according to the first embodiment. The oscillator 1 is, for example, a thermostatted crystal oscillator and outputs an oscillation signal of a predetermined oscillation frequency. The oscillator 1 adjusts the oscillation frequency based on the correction information that is stored before shipment and corrects the secular change of the oscillation frequency, thereby keeping the oscillation frequency of the oscillation signal output by itself after shipment constant.

  The external device 2 is, for example, a computer used when manufacturing the oscillator 1 and is electrically connected to the oscillator 1. The external device 2 measures the oscillation frequency of the oscillation signal output from the oscillator 1 over a predetermined period, and estimates the aging characteristic of the oscillation frequency. Then, the external device 2 generates correction information for correcting the secular change of the oscillation frequency based on the estimated secular change characteristic, and stores the correction information in the oscillator 1.

[Configuration of oscillator 1]
Subsequently, the configuration of the oscillator 1 will be described.
As shown in FIG. 1, the oscillator 1 includes an oscillation circuit 11, an output unit 12, a temperature detection unit 13, a storage unit 14, and a control unit 15.

  The oscillation circuit 11 is stored in a constant temperature bath (not shown), generates an oscillation signal of a predetermined oscillation frequency at a set temperature, and outputs the oscillation signal to the output unit 12. The oscillator circuit 11 includes a crystal oscillator, an amplifier circuit, and a variable capacitor. The quartz oscillator is, for example, a quartz oscillator (AT-cut quartz oscillator) using an AT-cut quartz piece. The amplification circuit amplifies the oscillation signal. The variable capacitance is, for example, a varicap diode, and changes a capacitance value when a control voltage is applied. When the control voltage is applied to the variable capacitance, the capacitance value of the oscillation circuit 11 changes, and the oscillation frequency of the oscillation signal output from the oscillation circuit 11 changes.

  The output unit 12 is, for example, a PLL (Phase Locked Loop) circuit. The output unit 12 adjusts the oscillation frequency of the oscillation signal output from the oscillation circuit 11, and outputs the oscillation signal of the adjusted oscillation frequency to the outside. Here, in the manufacturing process for manufacturing the oscillator 1, the oscillator 1 and the external device 2 are electrically connected via a cable, and the output unit 12 generates an oscillation signal of the oscillation frequency after adjustment to the external device 2. Output

  The temperature detection unit 13 detects the temperature inside the thermostatic chamber, and outputs temperature information indicating the detected temperature to the control unit 15. For example, the temperature detection unit 13 converts an analog signal indicating the detected temperature into a digital signal, and outputs the digital signal to the control unit 15 as temperature information.

  The storage unit 14 is configured of, for example, an EEPROM (Electrically Erasable Programmable Read Only Memory). The storage unit 14 is configured by the EEPROM, and holds the stored information even in a state where power is not supplied. In addition, the storage unit 14 stores, as temperature control information, information on a transfer function of PI control for bringing the temperature inside the thermostatic chamber close to the target temperature.

  In addition, the storage unit 14 acquires, from the external device 2, correction information used to correct the secular change of the oscillation frequency in the manufacturing process of the oscillator 1, and stores the correction information. Here, the correction information is, for example, a value of a parameter included in an arithmetic expression indicating aging.

  The storage unit 14 also stores elapsed time information indicating the operation time since the oscillator 1 was manufactured. The storage unit 14 may use an element capable of writing data by laser trimming, zener zapping, current trimming or the like and retaining the written data, instead of the EEPROM.

  The control unit 15 is configured of, for example, a digital signal processing IC (DSP) or a CPU. The control unit 15 includes a temperature control unit 151, a setting unit 152, a clock unit 153, and a correction unit 154.

  The temperature control unit 151 is configured to include, for example, a heater circuit for heating the thermostatic chamber, and controls the temperature inside the thermostatic chamber. Specifically, the temperature control unit 151 causes the temperature detected by the temperature detection unit 13 to approach the target temperature based on the temperature detected by the temperature detection unit 13 and the temperature control information stored in the storage unit 14. Feedback control to operate the heater circuit.

The setting unit 152 receives correction information used to correct aging of the oscillation frequency from the external device 2 connected to the oscillator 1 in the manufacturing process of the oscillator 1 and stores the correction information in the storage unit 14. The flow of processing for storing the correction information in the storage unit 14 will be described later.
The clock unit 153 counts time and outputs clocking information indicating the counted time to the correction unit 154.

  The correction unit 154 controls the control voltage applied to the oscillation circuit 11 so that the oscillation frequency of the oscillation signal output from the oscillation circuit 11 falls within a predetermined range. The correction unit 154 suppresses the change of the oscillation frequency due to the temperature change and the aging by performing the correction based on the aging of the oscillation frequency and the correction based on the temperature change as a factor different from the aging.

  Specifically, the correction unit 154 specifies the value of the control voltage to be applied to the oscillation circuit 11 based on the temperature information output from the temperature detection unit 13, and also measures time information output from the time measurement unit 153, and Based on the correction information stored in the storage unit 14, the value of the control voltage applied to the oscillation circuit 11 is specified. The correction unit 154 applies the total value of the specified control voltage values to the oscillation circuit 11, thereby suppressing the change in the oscillation frequency due to the temperature change and the secular change.

Here, the details of the process of correcting the secular change of the oscillation frequency will be described with reference to the flowchart. FIG. 2 is a flowchart according to the correction of the secular change of the oscillation frequency.
First, when power supply to the oscillator 1 is started, the correction unit 154 acquires elapsed time information stored in the storage unit 14 and indicates how long it has operated since the oscillator 1 was manufactured. The time is specified (S10).

Then, based on the value of the parameter (correction information) included in the arithmetic expression indicating the secular change of the oscillation frequency, the elapsed time specified in S10, and the arithmetic expression, the correction unit 154 performs oscillation based on the secular change. The amount of change in frequency is calculated (S20). Specifically, the correction unit 154 calculates the amount of change y based on the following equation (1).
y = round (A * (1-exp (-t / τ))) (1)

  Here, round () is a function for rounding, and t is an elapsed time. The elapsed time is, for example, the cumulative time that the oscillator 1 has been operated after the oscillator 1 has started to operate after being manufactured. Also, A and τ are parameters included in the arithmetic expression. Specifically, A is a parameter that indicates the maximum value (for example, 10 ppb) of the amount of change in oscillation frequency with aging, and τ is a parameter that indicates a time constant. Here, the values of the parameters A and τ are stored in the storage unit 14 in the manufacturing process of the oscillator 1.

  Subsequently, the correction unit 154 specifies a control voltage value for canceling out the change amount y corresponding to the change amount y of the oscillation frequency calculated in S20. Then, the correction unit 154 changes the oscillation frequency by an amount corresponding to the change amount y by applying a voltage of the specified control voltage value to the oscillation circuit 11 (S30).

  Subsequently, the correction unit 154 determines whether the elapsed time acquired in S10 is equal to or more than a predetermined upper limit time (S40). Here, the upper limit time is a time in which a change in the oscillation frequency due to secular change hardly occurs in the oscillator 1 and it is estimated that the update of the control voltage value is unnecessary. If it is determined that the elapsed time is equal to or greater than the upper limit time, the correction unit 154 ends the process of this flowchart, and if it is determined that the elapsed time is less than the upper limit time, the process proceeds to S50.

  Subsequently, the correction unit 154 determines whether a predetermined time (for example, one hour) has elapsed since the determination of S40 is performed based on the time counted by the clock unit 153 (S50). If it is determined that the predetermined time has elapsed, the correction unit 154 shifts the processing to S60, and if it is determined that the predetermined time has not elapsed, it re-executes S50.

Subsequently, the correction unit 154 updates the elapsed time by incrementing the elapsed time acquired in S10 (S60).
Subsequently, the correction unit 154 stores the elapsed time updated in S60 in the storage unit 14 (S70). As a result, the correction unit 154 does not supply power to the oscillator 1, and after a period in which the oscillator 1 does not operate occurs, the elapsed time stored in the storage unit 14 even if power is supplied to the oscillator 1 again Thus, the correction based on the secular change can be performed corresponding to the cumulative time when the oscillator 1 has been operated. Subsequently, the correction unit 154 shifts the processing to S20.

[Configuration of External Device 2]
Subsequently, the configuration of the external device 2 will be described.
The external device 2 includes a measuring unit 21, a specifying unit 22, and a setting unit 23, as illustrated in FIG.

  The measurement unit 21 measures the oscillation frequency of the oscillation signal output from the oscillator 1. Specifically, in the manufacturing process of the oscillator 1, the measuring unit 21 measures the oscillation frequency of the oscillation signal output from the oscillator 1 over a predetermined period (for example, one month).

  The identifying unit 22 identifies a change characteristic of the oscillation frequency in a predetermined period based on the measured oscillation frequency. Then, the identifying unit 22 estimates aging characteristics after a predetermined period has elapsed based on the variation characteristics, and generates correction information used by the oscillator 1 to correct aging of the oscillation frequency based on the estimated result. Do. FIG. 3 is a view showing the aging characteristics of the oscillation frequency measured by the measurement unit 21. As shown in FIG. As shown in FIG. 3, it can be confirmed that the amount of change of the oscillation frequency per unit time decreases with the passage of time, and the aging characteristics can be expressed by the above-mentioned equation (1). The identifying unit 22 identifies the values of the parameters A and τ included in the arithmetic expression shown in Expression (1) as the correction information based on the estimated aging characteristic.

  Before the measuring unit 21 measures the oscillation frequency, the setting unit 23 causes the oscillator 1 to stop the operation of the means for correcting the oscillation frequency based on an element different from aging. An element different from aging is, for example, a change in temperature or a change in amplitude of the oscillation signal. That is, the setting unit 23 transmits to the oscillator 1 stop instruction information for stopping the correction function based on, for example, a temperature change. By stopping the correction function based on the temperature change in the oscillator 1, the fluctuation of the oscillation frequency based on the aging can be identified with high accuracy.

  Further, the setting unit 23 stores the values of the parameters A and τ specified by the specifying unit 22 in the storage unit 14 provided in the oscillator 1. Specifically, the setting unit 23 transmits storage instruction information including the values of the parameters A and τ and instructing the oscillator 1 to store the value of the parameter in the storage unit 14.

  In addition, after transmitting the storage instruction information to the oscillator 1, the setting unit 23 acquires the values of the parameters A and τ as the correction information stored in the storage unit 14. Then, the setting unit 23 compares the acquired values of the parameters A and τ with the values of the parameters A and τ generated by the identifying unit 22, and the contents of the acquired values of the parameters A and τ are correct. Determine if

  If the setting unit 23 determines that the contents of the acquired values of the parameters A and τ are correct, the setting unit 23 transmits, to the oscillator 1, start instruction information for starting a correction function based on a temperature change. When the setting unit 23 determines that the contents of the acquired values of the parameters A and τ are not correct, for example, the setting unit 23 causes a display unit (not shown) provided in the external device 2 to display that effect. By doing this, it is possible to easily detect that a failure has occurred in the writing of the parameter value to the oscillator 1.

[Flow of parameter setting process]
Subsequently, the manufacturing process of the oscillator 1 will be described. Here, the flow of the parameter setting process for setting the value of the parameter to the oscillator 1 which is included in the manufacturing process will be described. FIG. 4 is a sequence diagram showing a flow of parameter setting processing.

  First, the setting unit 23 of the external device 2 transmits to the oscillator 1 stop instruction information for stopping the correction function based on the temperature change, which is a correction unit that corrects the oscillation frequency based on an element different from aging. Do.

When the setting unit 152 of the oscillator 1 receives the stop instruction information, the setting unit 152 stops the correction function based on the temperature change, which is executed by the correction unit 154 (S110).
Subsequently, the measuring unit 21 measures the oscillation frequency of the oscillation signal output from the oscillator 1 for a predetermined period (S120).

  Subsequently, the specifying unit 22 specifies the values of the parameters A and τ included in the arithmetic expression shown in Expression (1) based on the change characteristic of the oscillation frequency measured in S120 (S130).

Subsequently, the setting unit 23 of the external device 2 transmits storage instruction information instructing storage of the values of the parameters A and τ in the storage unit 14 of the oscillator 1 to the oscillator 1.
When receiving the storage instruction information, the setting unit 152 of the oscillator 1 stores the values of the parameters A and τ in the storage unit 14 (S140).

Subsequently, the setting unit 23 of the external device 2 transmits restart instruction information for instructing the oscillator 1 to restart, and causes the setting unit 152 of the oscillator 1 to restart the oscillator 1 (S150).
Subsequently, the setting unit 23 of the external device 2 transmits an acquisition request for the value of the parameter to the oscillator 1 and acquires the value of the parameter stored in the storage unit 14 of the oscillator 1. Subsequently, the setting unit 23 compares the value of the acquired parameter with the value of the parameter specified in S130, and verifies whether the value of the acquired parameter is correct (S160).

[Measurement result]
Subsequently, measurement results of aging of the oscillation frequency after shipment of the oscillator 1 according to the present embodiment will be described. FIG. 5 is a diagram showing the secular change of the oscillation frequency after shipment of the oscillator 1. The broken line shown in FIG. 5 indicates the change amount of the oscillation frequency when the correction unit 154 does not perform the correction corresponding to the secular change, and the dashed-dotted line indicates the oscillation frequency set when the correction unit 154 corrects the secular change. The solid line indicates the amount of change in oscillation frequency when the correction unit 154 performs correction in response to aging. As shown in FIG. 5, while the oscillation frequency gradually decreases with the passage of time, it can be confirmed that the correction unit 154 increases the correction amount of the oscillation frequency with the passage of time. As a result, it can be confirmed that the variation of the oscillation frequency of the oscillation signal output from the oscillator 1 is suppressed to within ± 1 ppb.

[Effect of First Embodiment]
As described above, the external device 2 according to the first embodiment measures the oscillation frequency output from the oscillator 1 for a predetermined period, and specifies the parameter value based on the change characteristic of the oscillation frequency in the predetermined period, and The value of the parameter is stored in the storage unit 14 of the oscillator 1.

  The parameter value can be set in a short period of time as compared to the conventional manufacturing process, and the oscillator 1 oscillates due to aging based on the value of the parameter stored in the storage unit 14 even after shipment. Variations in the frequency of the signal can be corrected. Therefore, it is possible to suppress the secular change after shipment while shortening the period from order acceptance to shipment of the oscillator 1.

Second Embodiment
[Oscillator 1 measures oscillation frequency and sets parameter values based on measurement results]
Subsequently, a second embodiment will be described. In the first embodiment, the external device 2 measures the oscillation frequency of the oscillator 1 and sets the value of the parameter in the oscillator 1 based on the measurement result. On the other hand, the second embodiment is different from the first embodiment in that the oscillator 1 measures the oscillation frequency and sets the parameter value based on the measurement result.

  FIG. 6 is a diagram showing the configuration of the oscillator 1 according to the second embodiment. As shown in FIG. 6, the control unit 15 of the oscillator 1 includes a measurement unit 21 and an identification unit 22 provided in the external device 2 of the first embodiment.

Further, the setting unit 152 according to the second embodiment, like the setting unit 23 provided in the external device 2 according to the first embodiment, the temperature provided in the correction unit 154 when the measurement unit 21 measures the oscillation frequency. Stop the change-based correction function.
In addition, the setting unit 152 causes the storage unit 14 to store the values of the parameters A and τ specified by the specifying unit 22.

  In addition, the setting unit 152 acquires the values of the parameters A and τ as the correction information stored in the storage unit 14, and compares the values with the values of the parameters A and τ generated by the identifying unit 22 to obtain the acquired values. It is determined whether the values of the parameters A and τ are correct. If the setting unit 152 determines that the contents of the acquired values of the parameters A and τ are not correct, the setting unit 152 outputs an error signal indicating that writing of the parameter values to the storage unit 14 has failed.

[Effect of Second Embodiment]
As described above, the oscillator 1 of the second embodiment has the function of the external device 2 according to the first embodiment for setting the parameters. By doing this, since the oscillator 1 can set the parameters without using the external device 2, the external device 2 is electrically connected to the oscillator 1 for measurement of the oscillation frequency and the like. The production efficiency of the oscillator 1 can be improved by omitting work and the like.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It is apparent to those skilled in the art that various changes or modifications can be added to the above embodiment. It is also apparent from the scope of the claims that the embodiments added with such alterations or improvements can be included in the technical scope of the present invention.

Reference Signs List 1 oscillator 11 oscillation circuit 12 output unit 13 temperature detection unit 14 storage unit 15 control unit 151 temperature control unit 152 setting unit 153 ... Timekeeping unit 154 ... correction unit 2 ... external device 21 ... measurement unit 22 ... identification unit 23 ... setting unit

Claims (1)

  It is an oscillator that corrects aging of the oscillation frequency of the oscillation signal output by itself.
  A measurement unit that measures the oscillation frequency over a predetermined period;
  A generation unit configured to generate correction information that is used by the oscillator to correct aging of the oscillation frequency based on change characteristics of the oscillation frequency during the predetermined period;
  A storage control unit for storing the generated correction information in a storage unit provided in the oscillator;
  The elapsed time indicating the total time of operation times since the oscillator was manufactured is measured, and the elapsed time is updated by storing the elapsed time in the storage unit, and the elapsed time stored in the storage unit The oscillation frequency is corrected based on the time and the change amount of the oscillation frequency based on the correction information stored in the storage unit, and the elapsed time stored in the storage unit is oscillation due to aging of the oscillator. A correction unit that stops updating of the elapsed time when the frequency change amount is equal to or greater than an upper limit time at which the amount of change in frequency is smaller than a predetermined amount;
  Oscillator with.

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