JP3879274B2 - Oscillator temperature compensation method and temperature compensation circuit thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a temperature compensation method for an oscillator using a vibrator such as a SAW (surface acoustic wave) resonator or a tuning fork vibrator, and a temperature compensation circuit thereof.
[0002]
[Prior art]
Conventionally, in this type of circuit, in the oscillator manufacturing stage, the temperature dependence of the frequency of each product is measured in advance, and the voltage signal level required to compensate the frequency deviation for each temperature is set to PROM (Programmable Lead One that is stored in an only memory) and shipped (for example, the invention described in Japanese Patent Laid-Open No. 63-240107).
[0003]
In such a conventional circuit, during the operation, the microcomputer reads the temperature detected by the temperature sensor thermally coupled to the vibrator, and reads the voltage signal level corresponding to the read temperature from the PROM. Based on the voltage signal level read from the PROM, a voltage signal is given from the microcomputer to the voltage controlled oscillator. A variable reactance element (for example, a variable capacitance diode) is connected to the voltage controlled oscillator, and the oscillation frequency is adjusted to a desired value by changing the reactance of the variable reactance element by the control voltage.
[0004]
[Problems to be solved by the invention]
As described above, in the conventional circuit, it is necessary to store the compensation amount of the frequency deviation with respect to each temperature in the PROM for each product. Therefore, a PROM (memory) having a large storage capacity is required and compared for the storage. Therefore, it takes a long time, and there is an inconvenience that the manufacturing cost (cost) increases.
[0005]
Accordingly, the present invention has been made in view of the above-described points, and an object of the present invention is to provide a temperature compensation method for an oscillator and a temperature compensation circuit for the same, in which the manufacturing cost is reduced by reducing the capacity of the memory. It is to provide.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object of the present invention, each invention described in claims 1 to 6 is configured as follows.
[0007]
That is, the invention according to claim 1 is an oscillator that compensates the oscillation frequency of an oscillator using a vibrator whose frequency deviation with respect to temperature is approximated by a second-order polynomial according to the detected temperature of the vibrator. In the temperature compensation method of the above, among the plurality of parameters in the polynomial, the value of at least one parameter having a large variation during the manufacture of the vibrator is obtained in advance as a unique value, and the value of the remaining parameter having a small variation Is a standard value, the value of each parameter is stored in advance, and the temperature of the vibrator is detected during operation of the oscillator, and at least the detected temperature and each value of the plurality of stored parameters The frequency deviation is calculated based on the frequency deviation of the oscillator, and the temperature compensation of the oscillation frequency of the oscillator is performed based on the obtained frequency deviation. A standard table describing the relationship between each temperature and the frequency deviation corresponding to each temperature, assuming an average value of the parameters in the polynomial, is further prepared in advance. The calculation of the frequency deviation at the time of operation of the oscillator is obtained by referring to the standard table according to the detected temperature of the vibrator, and when obtaining this, each value of the plurality of parameters and an average value of the parameters are obtained. The frequency deviation is corrected using a correction value obtained in advance based on the above.
[0010]
The invention according to claim 2 is used in the oscillator, and includes temperature detecting means for detecting the temperature of the vibrator whose frequency deviation with respect to the temperature is approximated by a second order polynomial, and a plurality of parameters in the polynomial, The value of at least one parameter having a large variation at the time of manufacturing the vibrator is determined in advance as a unique value, the remaining parameter value having a small variation is set as a standard value, and each value of each parameter is set in advance. Storage means for storing, frequency deviation calculating means for determining a frequency deviation based on the detected temperature of the temperature detecting means, and each value of a plurality of parameters stored in the storing means, and the frequency deviation calculating means Compensating means for compensating the oscillation frequency of the oscillator based on a frequency deviation, and a temperature compensation circuit of the oscillator, A standard table that describes the relationship between each temperature and the frequency deviation corresponding to each temperature, assuming an average value of the parameters, is further provided, and the frequency deviation calculating means includes a temperature detected by the temperature detecting means. The frequency deviation is obtained with reference to the standard table based on the above, and when obtaining this, the correction value obtained in advance based on each value of the plurality of parameters and the average value of the parameters is used. The frequency deviation is corrected.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0014]
First, prior to the description of the embodiment of the present invention, characteristics of SAW resonators and tuning fork vibrators among vibrators used in the oscillator will be described.
[0015]
Frequency deviation Delta] f / f _O of the SAW resonator and the tuning fork oscillator used in the oscillator is approximated by the following equation (1).
[0016]
Δf / f _o ≡ (f−f _o ) / f _o ≈α (θ−θ _p ) ² + Δf _p / f _o (1)
Where f: resonance frequency [Hz]
f _O : nominal frequency [Hz]
θ: Temperature [° C]
θ _P : Apex temperature [° C]
α: Temperature coefficient [℃ ^-2 ]
Δf _P / f _O : Frequency deviation at apex temperature (θ = θ _P ) Although partially overlapping, the explanation of each parameter in the equation (1) and the characteristic value in the SAW resonator are shown in FIG.
[0017]
Here, as shown in the equation (1), the frequency deviation of the SAW resonator and the tuning fork vibrator is a quadratic curve with respect to the temperature, and the first term on the right side of the equation (1) depends on the temperature. The second term on the right side of the frequency deviation represents the frequency deviation that does not depend on temperature.
[0018]
In the SAW resonator, the average temperature of the apex temperature θ _P = θ _P (typ) = 25 ° C., temperature coefficient α = α (type) = − 3.4 × 10 ⁻⁸ ° C ⁻² , Δf _P / f _O = 0 When such a condition is assumed, the expression (1) is expressed by the following expression (2).
[0019]
Δf / f _O ≈α (typ) {θ−θ _P (typ)} ² (2)
This average frequency deviation characteristic is shown in FIG.
[0020]
By the way, in an actual product, all three parameters of the apex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _{O at} the apex temperature vary among the products. FIG. 1 shows an example of the SAW resonator apex temperature θ _P , the temperature coefficient α, the average value of the frequency deviation Δf _P / f _{O at} the apex temperature, and variations thereof.
[0021]
The variation is shown in FIGS. 3 shows the variation of the vertex temperature θ _P , FIG. 4 shows the variation of the temperature coefficient α, and FIG. 5 shows the variation of the frequency deviation Δf _P / f _{O at} the vertex temperature. FIG. 6 shows the range of these total variations. In each figure, the horizontal axis represents the temperature θ [° C.], and the vertical axis represents the frequency deviation Δf / f _O [ppm].
[0022]
Next, a first embodiment of an oscillator temperature compensation circuit according to the present invention will be described with reference to the drawings.
[0023]
In the first embodiment, each value of the apex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _{O at} the apex temperature of the SAW resonator represented by the equation (1) is obtained in advance, and each of the obtained parameters is obtained. Is stored in advance, the temperature of the SAW resonator is detected during operation of the oscillator, and the frequency based on the equation (1) is detected using the detected temperature and each value of each parameter stored in advance. The deviation is obtained, and the oscillation frequency of the oscillator is temperature-compensated by the obtained frequency deviation.
[0024]
For this reason, as shown in FIG. 7, the first embodiment includes a temperature sensor 1, a microcomputer 2, a storage device 3, and a voltage controlled oscillator (VCO) 4. The microcomputer 2 is an A / D converter. And a D / A converter 24, a CPU (arithmetic processing unit) 22, a ROM (read only memory) 23, and a D / A converter 24.
[0025]
The temperature sensor 1 is configured to detect the temperature of the SAW resonator 5 shown in FIG. 8 and output the detected temperature to the A / D converter 21.
[0026]
The A / D converter 21 is configured to A / D convert the detected temperature in analog form from the temperature sensor 1 into a digital signal and output it to the CPU 22.
[0027]
The CPU 22 is configured to perform various determinations and arithmetic processing according to procedures stored in advance in the ROM 23 as will be described later, and to output signals according to the determinations and arithmetic results.
[0028]
The ROM 23 stores various determination and calculation procedures performed by the CPU 22 in advance.
[0029]
The D / A converter 24 is configured to D / A convert the digital output from the CPU 22 into an analog signal and output it to the voltage controlled oscillator 4.
[0030]
The storage device 3 is a user-written storage device (for example, PROM), and the vertex temperature θ _P , the temperature coefficient α, and the vertex temperature in the equation (1) for the SAW resonator 5 obtained in advance as described later. Each value of the frequency deviation Δf _P / f _O at is stored in advance.
[0031]
Next, an example of the circuit configuration of the voltage controlled oscillator 4 will be described with reference to FIG.
[0032]
The voltage controlled oscillator 4 is called a Colpitts type, and has an amplifying transistor Q1 as shown in FIG. 8, and the collector of the transistor Q1 is connected to an output terminal via a capacitor C3, and a coil. It is connected to the power supply via L1. The emitter of the transistor Q1 is grounded via a resistor R3. A capacitor C1 is connected between the base and emitter of the transistor Q1, and a capacitor C2 is connected in parallel to the resistor R3.
[0033]
One end of each of the resistors R1 and R2 is connected to the base of the transistor Q1, the other end of the resistor R1 is connected to a power source, and the other end of the resistor R2 is grounded. One electrode of the SAW resonator 5 is connected to the base of the transistor Q1, and the other electrode is connected to the voltage control terminal. The voltage control terminal is connected to the cathode side of the variable capacitance diode 6 for varying the frequency, and the anode side thereof is grounded. Furthermore, the voltage control terminal is connected to the output side of the D / A converter 24 of FIG.
[0034]
By the way, according to the circuit configuration shown in FIG. 8, as the voltage applied to the voltage control terminal of the voltage controlled oscillator 4 increases, the value of the capacitance of the variable capacitance diode 6 decreases, and as a result, the oscillation frequency increases. That is, a frequency lower than the oscillation frequency when the variable capacitance diode 6 is not connected cannot be obtained. Therefore, in order to adjust the frequency to the nominal frequency f _O , it is a condition that can be corrected that the frequency deviation Δf / f _O is negative. Therefore, it is necessary to design the frequency lower in advance.
[0035]
That is, the vibrator is designed so as to obtain an average characteristic as shown in FIG. In FIG. 9, the frequency deviation Δf _P / f _O at the vertex temperature is set to be −110 ppm. Therefore, in practice, the value of the frequency deviation Δf _P / f _{O at} the apex temperature is a value including the artificial frequency deviation in addition to the manufacturing variation of ± 100 ppm. By such a measure, as shown in FIG. 10, the frequency deviation Δf / f 2 _O can be kept in the negative range for all products.
[0036]
Next, temperature compensation of the oscillator according to the first embodiment having such a configuration will be described with reference to FIG.
[0037]
In the first embodiment, first, for the SAW resonator 5, the SAW resonator 5 is set to the values of the parameters of the vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _O at the vertex temperature in the equation (1). Find each in advance.
[0038]
The calculation of the value of each parameter is performed by changing the ambient temperature of each SAW resonator at intervals of 15 ° C. to obtain the oscillation frequency for each temperature, thereby creating an approximate curve and based on the created approximate curve. The vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _O at the vertex temperature are obtained.
[0039]
The values of the vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _{O at} the vertex temperature of the SAW resonator 5 thus obtained are stored in the storage device 3 in advance.
[0040]
During temperature compensation of the voltage controlled oscillator 4, the CPU 22 reads the detected temperature θ of the SAW resonator 5 detected by the temperature sensor 1 (step S 11), and the read detected temperature θ is stored in the storage device 3. Using the vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _{O at} the vertex temperature, the CPU 22 calculates the frequency deviation Δf / f _O of the SAW resonator at the detected temperature θ based on the equation (1). Is calculated (step S12).
[0041]
Next, the CPU 22 calculates a voltage level necessary for compensation of the voltage controlled oscillator 4 based on the calculated frequency deviation Δf / f _O , and the calculated voltage is D / A converted by the D / A converter 24. The voltage is supplied to the variable capacitance diode 6 connected to the voltage controlled oscillator 4 (step S13). As a result, the oscillation frequency of the voltage controlled oscillator 4 is corrected to a desired value.
[0042]
As described above, according to the first embodiment, only the values of the parameters of the equation (1) that approximately represent the frequency deviation need be stored in the storage device 3 in advance, so that the memory capacity can be reduced. Can be realized, and the manufacturing cost can be reduced.
[0043]
If each value of the above parameters is set by a variable resistor and read by an A / D converter at the start of operation, it is not necessary to mount a PROM as in the conventional case, and the cost is greatly reduced. Is feasible.
[0044]
In the first embodiment, the values of the parameters of the vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _O at the vertex temperature in the equation (1) are obtained in advance for each SAW resonator. The stored values are stored in the storage device 3 in advance. However, these three parameters are different in the degree of variation at the time of manufacturing the SAW resonator, and there are a variation that is largely unacceptable and a variation that is small and acceptable.
[0045]
Therefore, in the present invention, of the three parameters, for example, the parameter having a large variation is the vertex temperature θ _P and the frequency deviation Δf _P / f _{O at} the vertex temperature, and these values are obtained in advance for each SAW resonator. Alternatively, an average value common to the SAW resonators may be used for the temperature coefficient α having a small variation. In this case, the temperature coefficient α can be stored in the ROM 23 in place of the storage device 3.
[0046]
Next, a second embodiment of the temperature compensation circuit for an oscillator according to the present invention will be described with reference to FIGS.
[0047]
In the second embodiment, a standard correspondence table 7 of the temperature at the time of the average characteristic shown in the equation (2) and the frequency deviation corresponding to this temperature is created in advance as shown in FIG. A standard table 8 as shown in FIG. 13 corresponding to the correspondence table 7 is created in the ROM 23 in advance, and the temperature of the SAW resonator 5 is detected during operation of the oscillator, and the standard table 8 is determined based on the detected temperature. The frequency deviation is obtained with reference to this, and when this is obtained, the frequency deviation is corrected using a correction value described later.
[0048]
In the second embodiment, the hardware configuration is basically the same as that of the first embodiment shown in FIGS. 7 and 8. Therefore, the description of the configuration is omitted as appropriate unless necessary. The temperature compensation will be described in detail below.
[0049]
The correspondence table 7 shown in FIG. 12 describes the temperature and the absolute value of the frequency deviation with respect to the temperature. Further, the operating temperature range of the voltage controlled oscillator 4 is, for example, −40 ° C. to 85 ° C., and the variation of the apex temperature θ _P is ± 15. Therefore, the temperature range including this variation is −55 as shown in FIG. ° C to 100 ° C.
[0050]
In this example, since both the A / D converter 21 and the D / A converter 24 shown in FIG. 7 have a resolution of 8 bits, a temperature range of −55 ° C. to 100 ° C. is set at a resolution of “256”. Can be detected. Further, the top address of the standard table 8 in the ROM 23 shown in FIG. 13 is “0000H” for simplicity. Therefore, for example, the frequency deviation amount for 25 ° C. is stored in the address “0084H”. The data of each address is the frequency deviation amount at that temperature, and the range of 0 to 220 ppm is stored with 8-bit resolution.
[0051]
Next, temperature compensation of the oscillator according to the second embodiment having such a standard table will be described with reference to FIG.
[0052]
In the second embodiment, first, the values of the parameters of the vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _O at the vertex temperature in the equation (1) are obtained in advance for each SAW resonator. Since this method is the same as in the case of the first embodiment, the description thereof is omitted.
[0053]
Then, from the obtained vertex temperature θ _P , temperature coefficient α, and each value of the frequency deviation Δf _P / f _{O at} the vertex temperature, and the average values θ _P (typ) and α (typ) of these parameters, The correction amount T of the vertex temperature θ _P , the correction amount A of the temperature coefficient α, and the correction amount F of the frequency deviation are calculated by the following equations (3) to (5).
[0054]
T = θ _P (typ) −θ _P (3)
A = α / α (typ) (4)
F = Δf _P / f _O (5)
The calculated correction amounts T, A, and F are stored in the storage device 3 in advance.
[0055]
Further, a correspondence table as shown in FIG. 12 described above is created, and a standard table 8 corresponding to the correspondence table is stored in the ROM 23 in advance.
[0056]
When the temperature of the voltage controlled oscillator 4 is compensated, first, the CPU 22 reads the correction amounts T, A, and F stored in the storage device 3 (step S1).
[0057]
Next, the CPU 22 reads the detected temperature θ of the SAW resonator 5 detected by the temperature sensor 1 (step S2). Then, the vertex temperature correction amount T is added to the detected temperature θ to correct the detected temperature θ (step S3).
[0058]
For example, if the apex temperature θ _P is 20 ° C. and the average apex temperature is 25 ° C., the correction amount T of the apex temperature θ _P is 5 ° C. from the equation (3). For this reason, when the detected temperature θ of the temperature sensor 1 is 10 ° C., 5 ° C. is added in step S3, and the corrected temperature θ becomes 15 ° C.
[0059]
In the next step S4, the CPU 22 calculates the address of the standard table 8 corresponding to the corrected temperature θ. For example, when the corrected temperature θ is 15 ° C., “0074H” is an address to be accessed. Thus, by calculating the address based on the temperature added by the correction amount T, it is possible to read the frequency deviation in which the error from the average value of the vertex temperature θ _P is corrected.
[0060]
Next, in step S5, the CPU 22 reads data corresponding to the frequency deviation Δf / f _O from the obtained address. However, the frequency deviation Delta] f / f _O read here, merely the temperature coefficient α is data for the case of the average value. Therefore, in the next step S6, a process of multiplying the frequency deviation Δf / f _O by the correction amount A is performed. By this process, the variation in the temperature coefficient α is corrected.
[0061]
In the next step S7, the correction amount F is added to the value obtained in step S6 to correct the value corresponding to Δf _P / f _O.
[0062]
The frequency deviation amount corresponding to the detected temperature of the SAW resonator 5 is calculated by a series of processes as described above.
[0063]
Next, in step S8, a voltage signal level to be output to the D / A converter 24 is calculated based on the calculated frequency deviation amount. Here, the voltage signal level is calculated based on a known relational expression obtained from the characteristics of the variable capacitance diode 6 and the voltage controlled oscillator 4. For example, when the relational expression is non-linear, a target voltage signal level is obtained with reference to a table (not shown).
[0064]
In the next step S9, the calculated voltage signal level is output. And it returns to step S2 and repeats the above series of processes.
[0065]
In general, the time constant of the temperature change is sufficiently slower than the operation speed of the microcomputer, so that the processing from step S2 to step S9 may be repeated at regular intervals by a timer.
[0066]
By repeating such a series of processes, the D / A converter 24 always outputs a voltage signal that compensates for the frequency deviation amount corresponding to the temperature at that time, whereby the capacitance of the variable capacitance diode 6 is increased. As a result, the voltage controlled oscillator 4 continues to oscillate at a desired frequency.
[0067]
As described above, according to the second embodiment, the standard table is used, so that each product can be used in common, and as a result, the PROM for each product can be used as in the conventional case. This eliminates the need for memorizing the voltage required for frequency deviation compensation for each temperature, thereby reducing the manufacturing cost.
[0068]
In the second embodiment, for the SAW resonator, the values of the parameters of the vertex temperature θ _P , the temperature coefficient α, and the frequency deviation Δf _P / f _O at the vertex temperature in the equation (1) are obtained, and each SAW is obtained. Correction values T, A, and F are obtained as shown in equations (3) to (5) from the values of each parameter obtained for each resonator and the average values of these parameters, and the frequency is calculated using a standard table. When calculating the deviation, all of the correction amount was used.
[0069]
However, the above three parameters are different in the degree of variation at the time of manufacture of the SAW resonator, and the variation is large and unacceptable, and the variation is small and acceptable.
[0070]
Therefore, for example, when the variation of the temperature coefficient α is acceptable among the three parameters, the variation is not necessarily corrected, and such a case is also included in the present invention. In this case, the process of step S6 in FIG. 14 is omitted.
[0071]
In each of the above embodiments, the temperature compensation of the oscillator used for the SAW resonator has been described. However, the present invention is naturally applicable to the temperature compensation of the oscillator using the tuning fork vibrator.
[0072]
The temperature detecting means according to claim 2 corresponds to the temperature sensor 1 of FIG. 7, and similarly, the storage means is in the storage device 3 or the ROM 23, the frequency deviation calculating means is in the CPU 22, etc., and the compensating means is in FIG. It corresponds to each variable capacitance diode. The standard table according to claim 2 corresponds to the standard table 8 of FIG.
[0074]
【The invention's effect】
As described above, according to the present invention, since only a plurality of parameters in a second-order polynomial whose frequency deviation is approximately expressed need to be stored in advance, the storage capacity of the storage means can be reduced. In addition, the manufacturing cost can be reduced by the reduction.
[0075]
Further, in the present invention, when a frequency deviation is obtained using a standard table, the standard table can be commonly used for each product, so that the frequency deviation for each temperature is stored in the PROM for each product as in the prior art. The operation of storing the voltage necessary for compensation is not necessary, and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating each parameter of an equation indicating a frequency deviation of a vibrator and a characteristic value in a SAW resonator.
FIG. 2 is a diagram showing characteristics of an average frequency deviation of a vibrator.
FIG. 3 is a diagram showing variation in apex temperature.
FIG. 4 is a diagram showing variations in temperature coefficient.
FIG. 5 is a diagram showing a variation in frequency deviation at an apex temperature.
FIG. 6 is a diagram showing a range of these comprehensive variations.
FIG. 7 is a block diagram showing an example of a configuration of a first embodiment of a temperature compensation circuit for an oscillator according to the present invention.
8 is a circuit diagram showing an example of a circuit configuration of the voltage controlled oscillator of FIG. 7. FIG.
FIG. 9 is a diagram for explaining an average characteristic of a frequency deviation of a SAW resonator when a variable capacitance diode is considered.
FIG. 10 is a diagram showing a range of variation in that case.
FIG. 11 is a flowchart showing an example of temperature compensation of the oscillator according to the first embodiment.
FIG. 12 is a diagram showing an example of a correspondence table according to the second embodiment of the temperature compensation circuit of the oscillator of the present invention.
13 is a diagram showing an example of a standard table created according to the correspondence table shown in FIG.
FIG. 14 is a flowchart showing an example of temperature compensation of the oscillator according to the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Temperature sensor 2 Microcomputer 3 Memory | storage device 4 Voltage control oscillator 5 SAW resonator 6 Variable capacity diode 7 Correspondence table 8 Standard table 21 A / D converter 22 CPU (arithmetic processing unit)
23 ROM
24 D / A converter

Claims (2)

In an oscillator temperature compensation method for compensating an oscillation frequency of an oscillator using a vibrator whose frequency deviation with respect to temperature is approximated by a second-order polynomial according to a detected temperature of the vibrator,
Among the plurality of parameters in the polynomial, the value of at least one parameter having a large variation at the time of manufacturing the vibrator is obtained in advance as a value unique to the vibrator, and the remaining parameter value having a small variation is set as a standard value. Value and store the value of each parameter in advance,
During the operation of the oscillator, the temperature of the vibrator is detected, and a frequency deviation is obtained based on at least the detected temperature and each value of the stored parameters,
A temperature compensation method for an oscillator configured to perform temperature compensation for an oscillation frequency of the oscillator based on the obtained frequency deviation,
A standard table describing the relationship between each temperature and the frequency deviation corresponding to each temperature, assuming an average value of the parameter in the polynomial, is further created in advance,
The calculation of the frequency deviation at the time of operation of the oscillator is obtained by referring to the standard table according to the detected temperature of the vibrator, and when obtaining this, each value of the plurality of parameters and an average value of the parameters are calculated. A method for compensating temperature of an oscillator, wherein the frequency deviation is corrected using a correction value obtained in advance based on the above. A temperature detecting means for detecting a temperature of the vibrator which is used in the oscillator and whose frequency deviation with respect to the temperature is approximated by a second order polynomial;
Among the plurality of parameters in the polynomial, the value of at least one parameter having a large variation at the time of manufacturing the vibrator is obtained in advance as a value unique to the vibrator, and the value of the remaining parameter having a small variation is determined. A storage means for storing each value of each parameter in advance as a standard value;
A frequency deviation calculating means for obtaining a frequency deviation based on a detected temperature of the temperature detecting means and values of a plurality of parameters stored in the storage means;
Compensating means for compensating the oscillation frequency of the oscillator based on the frequency deviation obtained by the frequency deviation calculating means;
An oscillator temperature compensation circuit comprising:
A standard table describing the relationship between each temperature and the frequency deviation corresponding to each temperature, assuming an average value of the parameters in the polynomial;
The frequency deviation calculating means obtains a frequency deviation by referring to the standard table based on the temperature detected by the temperature detecting means, and when obtaining this, each value of the plurality of parameters and an average value of the parameters are calculated. A temperature compensation circuit for an oscillator, wherein the frequency deviation is corrected using a correction value obtained in advance based on the above.

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