JP2014171199A - Temperature-compensated oscillator and method of manufacturing temperature-compensated oscillator - Google Patents

Abstract

A plurality of temperature frequency characteristics are switched and operated.
A temperature-compensated oscillator 100 is provided in a temperature detection unit 3 that detects an ambient temperature, an oscillation circuit 1 that includes a crystal resonator 11, and an oscillation circuit 1, and an impedance changes according to a control voltage. The variable impedance element 2 for changing the oscillation frequency of the oscillation circuit, the EEPROM 4 for storing constants of a nonlinear function indicating the relationship between the ambient temperature and the control voltage, in association with the plurality of temperature frequency characteristics of the temperature compensated oscillator 100, The temperature detecting unit 3 detects one temperature frequency characteristic from among the temperature detecting unit 63 based on a constant non-linear function stored in the EEPROM 4 in association with the temperature frequency characteristic selected by the selecting unit. A control voltage output unit 64 that outputs a control voltage corresponding to the ambient temperature.
[Selection] Figure 1

Description

  The present invention relates to a temperature compensated oscillator and a method for manufacturing the temperature compensated oscillator.

  Conventionally, there has been known a temperature compensated oscillator that includes an oscillation circuit including a crystal resonator and maintains a temperature frequency characteristic in a predetermined state (see, for example, Patent Document 1 and Patent Document 2). FIG. 7 is a diagram illustrating a configuration example of a conventional temperature compensated oscillator 200. The temperature compensated oscillator 200 includes an oscillation circuit 201 including a crystal resonator 211, a variable impedance element 202, a temperature detection unit 203, an EEPROM 204, and a temperature compensation unit 206.

  In the crystal resonator 211, an AT-cut crystal piece having a temperature frequency characteristic in which the frequency changes in a cubic function with respect to a temperature change is used, and in a state where the temperature compensation by the temperature compensation unit 206 is not performed, The oscillation circuit 201 has a temperature frequency characteristic as shown in FIG.

  The temperature compensation unit 206 applies a voltage to the variable impedance element 202 so that the temperature frequency characteristic of the variable impedance element 202 becomes a temperature frequency characteristic obtained by inverting the temperature frequency characteristic of the oscillation circuit 201. That is, the temperature compensation unit 206 approximates a temperature frequency characteristic obtained by inverting the temperature frequency characteristic of the oscillation circuit 201 with a cubic function, and applies a voltage generated based on the cubic function to the variable impedance element 202. In addition, the temperature frequency deviation amount of the oscillation frequency of the temperature compensated oscillator 200 can be set to a predetermined threshold value or less.

Japanese Patent No. 3310550 Japanese Patent No. 4891131

  By the way, a suitable temperature frequency characteristic differs depending on a product equipped with a temperature compensated oscillator. In addition, depending on the use conditions of a product equipped with a temperature compensated oscillator, different types of temperature frequency characteristics such as a positive temperature gradient and a negative temperature gradient may be required. For example, there is a case where what temperature frequency characteristic is suitable for a prototype equipped with a temperature compensated oscillator is tested.

  However, since the conventional temperature compensated oscillator cannot change the temperature frequency characteristic, it has been necessary to use a temperature compensated oscillator having a different temperature frequency characteristic for each product. In addition, in order to investigate a suitable temperature frequency characteristic, it is necessary to reattach a temperature compensated oscillator having a different temperature frequency characteristic to the prototype every time the operation test for one temperature frequency characteristic is completed. Was complicated.

  Therefore, the present invention has been made in view of these points, and an object thereof is to provide a temperature compensated oscillator capable of operating by switching a plurality of temperature frequency characteristics, and a method for manufacturing the temperature compensated oscillator.

  According to a first aspect of the present invention, there is provided a temperature compensated oscillator that changes an oscillation frequency according to a control voltage, a temperature detection unit that detects an ambient temperature, an oscillation circuit that includes a vibrator, and the oscillation circuit. A variable impedance element that changes impedance according to the control voltage to change the oscillation frequency of the oscillation circuit, and the ambient temperature and the control voltage in association with a plurality of temperature frequency characteristics of the temperature compensated oscillator. A storage unit that stores a constant of a nonlinear function indicating a relationship between the temperature frequency characteristic, a selection unit that selects one temperature frequency characteristic from the plurality of temperature frequency characteristics, and the temperature frequency characteristic selected by the selection unit in association with the temperature frequency characteristic Based on the nonlinear function of the constant stored in the storage unit, the control voltage corresponding to the ambient temperature detected by the temperature detection unit is output. To provide a temperature compensated oscillator and a control voltage output unit.

  In the temperature compensated crystal oscillator, the operation mode of the temperature compensated oscillator is different from the adjustment mode and the adjustment mode in which the control voltage output unit outputs the control voltage based on the adjustment constant. Based on a normal operation mode for causing the control voltage output unit to output the control voltage, the storage unit temporarily stores an adjustment constant for the nonlinear function, and the control voltage The output unit outputs the control voltage corresponding to the ambient temperature based on the nonlinear function of the adjustment constant stored in the storage unit when the operation mode is the adjustment mode, and the operation mode In the normal operation mode, the control voltage corresponding to the ambient temperature is generated based on the nonlinear function of the constant stored in the storage unit. Good.

  The temperature compensated crystal oscillator further includes a selection information acquisition unit that acquires selection information for selecting one temperature frequency characteristic from the plurality of temperature frequency characteristics, and the selection unit is based on the selection information. One temperature frequency characteristic may be selected from the plurality of temperature frequency characteristics.

  According to a second aspect of the present invention, there is provided a method of manufacturing a temperature compensated oscillator including an oscillation circuit that changes an oscillation frequency in accordance with a control voltage, wherein a constant for adjusting a nonlinear function for outputting the control voltage is set. A step of storing a plurality of values in the storage unit, a step of adjusting the ambient temperature of the temperature compensated oscillator, and a non-linear function to which each of the plurality of adjustment constants stored in the storage unit is applied at the ambient temperature A step of measuring the oscillation frequency when a control voltage is output for each of the plurality of adjustment constants, the oscillation frequency measured based on each of the adjustment constants, and when the oscillation frequency is measured A plurality of constants for generating the control voltage corresponding to each of a plurality of temperature frequency characteristics of the oscillation circuit based on the ambient temperature of In association with the temperature-frequency characteristics, providing a step of storing a plurality of the constants calculated in the storage unit, a method of manufacturing a temperature compensated oscillator comprising a.

  In the method of manufacturing the temperature compensated oscillator, in the step of calculating the constant, a plurality of pieces of relationship information indicating a relationship between the ambient temperature and the oscillation frequency at the ambient temperature are obtained, and the plurality of obtained relationship information, The constant may be calculated based on the oscillation frequency measured based on the plurality of adjustment constants and the ambient temperature when the oscillation frequency is measured.

  The crystal oscillator according to the present invention has an effect that it can operate by switching a plurality of temperature frequency characteristics.

It is a figure which shows the structural example of the temperature compensation oscillator of this embodiment. It is a figure which shows the example of the several temperature frequency characteristic which concerns on this embodiment. It is a figure which shows the example of the several temperature frequency characteristic which concerns on this embodiment. It is a figure which shows the example of the several temperature frequency characteristic which concerns on this embodiment. It is a figure which shows the example of the several temperature frequency characteristic which concerns on this embodiment. It is a functional block diagram of the temperature compensation part which concerns on this embodiment. It is a figure which shows the outline | summary of the method of manufacturing a temperature compensation oscillator in the adjustment mode which concerns on this embodiment. It is a flowchart which shows the flow of the process which selects the constant of the cubic function which concerns on this embodiment. It is a flowchart which shows the flow of the process which manufactures the temperature compensation oscillator which concerns on this embodiment. The structural example of the conventional crystal oscillator is shown. It is a figure which shows the frequency temperature characteristic in case the temperature compensation is not performed in the conventional crystal oscillator.

[Circuit configuration of temperature compensated oscillator]
FIG. 1 is a diagram illustrating a configuration example of a temperature compensated oscillator 100 according to the present embodiment.
The temperature compensated oscillator 100 includes an oscillation circuit 1, a variable impedance element 2, a temperature detection unit 3, an EEPROM (Electrically Erasable Programmable Read Only Memory) 4, and a temperature compensation unit 6.

  The oscillation circuit 1 includes a crystal resonator 11, an amplifier circuit, and a variable impedance element 2. The crystal unit 11 is, for example, a crystal unit using an AT cut crystal piece (AT cut crystal unit). Note that the oscillation circuit 1 may include a piezoelectric element such as a micro electro mechanical system (MEMS) element or a surface acoustic wave element that can approximate a quadratic function as long as it is a frequency oscillation element, instead of the crystal resonator 11. .

  The variable impedance element 2 is, for example, a varicap diode or an element group configured by series connection of an FET and a resistor. The variable impedance element 2 is arranged so that the impedance viewed from the crystal unit 11 changes. The impedance of the variable impedance element 2 changes according to a control voltage generated by a temperature compensation unit 6 described later. As the impedance changes, the variable impedance element 2 changes the oscillation frequency of the oscillation circuit 1.

  The temperature detection unit 3 is a temperature sensor that detects an ambient temperature and outputs an analog signal corresponding to the ambient temperature, for example. The temperature detector 3 may convert an analog signal corresponding to the temperature into a digital signal and output the digital signal.

  The EEPROM 4 functions as a storage unit and holds stored data even when power is not supplied. The EEPROM 4 stores a constant of a non-linear function indicating the relationship between the ambient temperature and the control voltage in association with the plurality of temperature frequency characteristics of the temperature compensated oscillator 100. “Nonlinear function constant” in the present embodiment is a generic term for coefficients and constants included in the nonlinear function. In this embodiment, a cubic function that can easily approximate the temperature frequency characteristic of the crystal unit 11 is used as the nonlinear function, but other higher-order functions may be used as the nonlinear function. Instead of the EEPROM 4, an element that can write data by laser trimming, zener zapping, current trimming, or the like and can hold the written data may be used.

  Furthermore, the EEPROM 4 stores a constant for adjusting a nonlinear function for outputting a control voltage. This adjustment constant is used when the temperature compensation unit 6 outputs a control voltage when an operation mode described later is the adjustment mode. Details of this processing will be described later.

  In the present embodiment, the plurality of temperature frequency characteristics have different temperature gradients indicating the ratio of the frequency shift amount to the ambient temperature, for example. FIG. 2 is a diagram illustrating an example of a plurality of temperature frequency characteristics according to the present embodiment. The horizontal axis indicates the ambient temperature, and the vertical axis indicates the frequency shift amount with respect to the oscillation frequency when the ambient temperature is the reference temperature (for example, 25 ° C.). FIG. 2A is a diagram showing a temperature frequency characteristic with a temperature gradient of almost zero. FIG. 2B is a diagram illustrating a temperature frequency characteristic having a positive temperature gradient. FIG. 2C is a diagram illustrating a temperature frequency characteristic having a negative temperature gradient. FIG. 2D is a diagram showing a temperature frequency characteristic having a convex temperature gradient in which the temperature gradient changes from positive to negative near the reference temperature.

The temperature frequency characteristic with a positive temperature gradient has the characteristic that the lower the temperature, the lower the frequency at the reference temperature, and the higher the temperature, the higher the frequency at the reference temperature. ing.
The temperature frequency characteristic with a negative temperature gradient has the characteristic that the lower the temperature, the higher the frequency at the reference temperature, and the higher the temperature, the lower the frequency at the reference temperature. ing.
The temperature frequency characteristic having a convex temperature gradient has a characteristic that the frequency is lower than the frequency at the reference temperature as the temperature is further away from the reference temperature.

  FIG. 3 is a functional configuration diagram of the temperature compensation unit 6 according to the present embodiment. As shown in FIG. 3, the temperature compensation unit 6 functions as a mode selection unit 61, a selection information acquisition unit 62, a selection unit 63, and a control voltage output unit 64. The temperature compensation unit 6 is connected to an input terminal 7 for inputting a signal to the selection information acquisition unit 62.

  The mode selection unit 61 selects an operation mode of the temperature compensated oscillator 100 from an adjustment mode and a normal operation mode different from the adjustment mode. For example, the mode selection unit 61 selects an operation mode based on a signal input from the input terminal 7 of the circuit constituting the temperature compensation unit 6. Here, the adjustment mode is a mode for outputting a control voltage based on an adjustment constant of a cubic function. The temperature compensated oscillator 100 can be manufactured by calculating a plurality of constants used in the normal operation mode based on the measurement result using the adjustment mode.

  The normal operation mode is a mode in which the control voltage output unit 64 outputs a control voltage based on a constant stored in the EEPROM 4 and corresponding to the temperature frequency characteristic selected by the selection unit 63. The normal operation mode is a mode that is selected after the constants of a plurality of cubic functions are determined in the adjustment mode. The temperature compensated oscillator 100 holds constants corresponding to a plurality of temperature frequency characteristics calculated in advance using the adjustment mode in the EEPROM 4, and uses the constants held in the EEPROM 4 in the normal operation mode to obtain a suitable temperature. An oscillation signal according to the frequency characteristic can be output.

  The selection information acquisition unit 62 acquires selection information for selecting one temperature frequency characteristic from a plurality of temperature frequency characteristics in the normal operation mode. Specifically, the selection information acquisition unit 62 acquires selection information indicated by the serial signal input to the input terminal 7. Here, the selection information is, for example, a code assigned in advance to each of the plurality of temperature frequency characteristics.

  The selection unit 63 selects one temperature frequency characteristic from the plurality of temperature frequency characteristics based on the selection information acquired by the selection information acquisition unit 62 in the normal operation mode. For example, the selection unit 63 stores a constant of a cubic function indicating one temperature frequency characteristic corresponding to the acquired selection information for a register provided in a circuit constituting the temperature compensation unit 6. By storing the address, one temperature frequency characteristic is selected.

  The selection information acquisition unit 62 and the selection unit 63 may select one temperature frequency characteristic by a method other than a method using a code previously assigned to the temperature frequency characteristic. For example, the selection information acquisition unit 62 may receive a serial signal indicating data related to temperature frequency characteristics, and select one temperature frequency characteristic from a plurality of temperature frequency characteristics based on the data received by the selection unit 63. Data related to temperature frequency characteristics include, for example, data indicating the ambient temperature and frequency of the inflection point of the curve indicating the temperature frequency characteristics, data indicating the amount of frequency deviation from the reference temperature at the start point and end point of the curve, Data indicating the slope of the temperature frequency characteristic. The selection unit 63 calculates the inflection point of the curve indicating the temperature frequency characteristic and the frequency shift amount at each ambient temperature based on the constants of the plurality of temperature frequency characteristics, and compares the calculated data with the received data. Do. Then, the selection unit 63 selects the temperature frequency characteristic closest to the temperature frequency characteristic indicated by the received data.

  The EEPROM 4 stores data such as the inflection point of the curve indicating the temperature frequency characteristic and the frequency shift amount at each ambient temperature in association with each of the plurality of temperature frequency characteristics. May calculate the similarity between these data and the received data and select the temperature frequency characteristic.

The control voltage output unit 64 outputs a control voltage corresponding to the ambient temperature detected by the temperature detection unit 3 based on the cubic function of the adjustment constant stored in the EEPROM 4 when the operation mode is the adjustment mode. To do.
In addition, when the operation mode is the normal operation mode, the control voltage output unit 64 is based on a constant cubic function stored in the EEPROM 4 in association with the temperature frequency characteristic selected by the selection unit 63. A control voltage corresponding to the ambient temperature detected by 3 is generated.

[Processing in adjustment mode]
As described above, the operation of the temperature compensated oscillator 100 differs between the adjustment mode and the normal operation mode. First, the adjustment mode process will be described with reference to a flowchart. FIG. 4 is a diagram illustrating an outline of a system for manufacturing the temperature compensated oscillator 100 using the adjustment mode according to the present embodiment. FIG. 5 is a flowchart showing a flow of processing for manufacturing the temperature compensated oscillator according to the present embodiment.

  As shown in FIG. 4, the temperature compensated oscillator 100 set to the adjustment mode is accommodated in the temperature test tank 20 and connected to the computer 30 and the frequency measuring device 40. Next, the temperature is adjusted by the computer 30 so that the temperature inside the temperature test chamber 20 becomes a temperature within a predetermined range.

  Subsequently, the computer 30 stores a plurality of cubic function adjustment constants for outputting the control voltage in the EEPROM 4. The computer 30 sets the temperature of the temperature test chamber 20 to the first temperature and adjusts the ambient temperature of the temperature compensated oscillator 100 (S1).

  Subsequently, the computer 30 outputs a control voltage based on a cubic function to which each of a plurality of adjustment constants stored in the EEPROM 4 is applied via the frequency measuring device 40 at the ambient temperature adjusted in S1. The oscillation frequency of the temperature compensated oscillator 100 is measured for each of a plurality of adjustment constants.

  That is, the computer 30 measures the oscillation frequency while adjusting the adjustment constant (S2). Specifically, the control voltage output unit 64 outputs a control voltage based on a cubic function of a plurality of adjustment constants stored in the EEPROM 4. Next, based on the adjustment constant stored in the EEPROM 4, the frequency measuring device 40 measures the frequency of the oscillation signal output in a state where the control voltage generated by the temperature compensation unit 6 is applied to the variable impedance element 2. . The computer 30 stores relation information indicating the relation between the ambient temperature and the frequency of the oscillation signal measured at the ambient temperature in the internal memory of the computer 30.

  Subsequently, the computer 30 determines whether or not frequencies have been measured for all temperatures prepared in advance (S3). If the computer 30 determines that the frequency is measured while adjusting the adjustment constants at all temperatures, the process proceeds to S4. If the computer 30 determines that the frequency is not measured at all temperatures, the process proceeds to S1. .

  Subsequently, the computer 30 acquires a plurality of relationship information indicating the relationship between the ambient temperature and the oscillation frequency of the temperature compensated oscillator 100 at the ambient temperature, and based on the acquired plurality of relationship information and a plurality of adjustment constants. A constant is calculated based on the measured oscillation frequency and the ambient temperature when the oscillation frequency is measured (S4). Specifically, the computer 30 first acquires information for specifying a temperature frequency characteristic for which a constant is to be calculated. The information specifying the temperature frequency characteristic is information indicating a relationship between a plurality of ambient temperatures and the frequency deviation amount at the temperature.

Next, the computer 30 generates control voltages corresponding to each of a plurality of temperature frequency characteristics of the temperature compensated oscillator 100 based on the oscillation frequency measured with each adjustment constant at each ambient temperature and the ambient temperature. A plurality of constants for generation are calculated (S4). Subsequently, the computer 30 stores constants corresponding to each of the plurality of temperature frequency characteristics in the EEPROM 4 (S5).
By performing the processing as described above, the temperature compensated oscillator 100 operating with a plurality of temperature frequency characteristics is manufactured.

Hereinafter, processing for calculating a constant for generating the control voltage will be described in detail.
The oscillation frequency f _x of the general oscillation signal of the crystal oscillator circuit using an AT-cut crystal oscillator, the third-order function of the ambient temperature T, is approximately expressed by the following equation (1).
f _x = α _x (T−T _0x ) ³ + β _x (T−T _0x ) + γ _x (1)
Here, α _x , β _x , and γ _x are constants specific to each AT-cut crystal resonator, and β _x depends on the cutting angle of the crystal piece. T _0x is the inflection point temperature, and is usually around 25 ° C.

The control voltage output unit 64 outputs a control voltage approximated to an ideal cubic curve with respect to the ambient temperature T. This control voltage is
V _c ′ = α ′ (T−T ₀ ′) ³ + β ′ (T−T ₀ ′) + γ ′ (2)
It is represented by

In order to calculate a constant of a cubic function corresponding to a plurality of temperature frequency characteristics, the computer 30 uses a plurality of combinations of α ′, β ′, γ ′ and T ₀ ′ corresponding to the equation (2) as adjustment constants. Is stored in the EEPROM 4. Then, the computer 30 causes the temperature compensated oscillator 100 to output a control voltage using each adjustment constant at a plurality of ambient temperatures. Here, the adjustment constants used at each of the plurality of ambient temperatures may be different. The computer 30 can apply the adjustment constant to the temperature compensated oscillator 100 to measure the oscillation frequency, and obtain the optimum coefficient and constant of the cubic function for the target frequency temperature characteristic.

[Processing in normal operation mode]
Next, processing performed in the temperature compensation unit 6 in the normal operation mode will be described using a flowchart. FIG. 6 is a flowchart showing the flow of processing when a constant of a cubic function according to this embodiment is selected and an oscillation signal is output.

  In the normal operation mode, the selection information acquisition unit 62 selects one temperature frequency characteristic (S11). Specifically, the selection information acquisition unit 62 selects one temperature frequency characteristic from a plurality of temperature frequency characteristics stored in the EEPROM 4 by acquiring selection information indicated by the serial signal input to the input terminal 7. Get selection information to do.

  Subsequently, the selection unit 63 selects one temperature frequency characteristic from the plurality of temperature frequency characteristics stored in the EEPROM 4 based on the selection information acquired by the selection information acquisition unit 62. For example, the selection unit 63 selects an address of the EEPROM 4 in which a constant of a cubic function indicating one temperature frequency characteristic is stored, and stores the selected address in a register provided in a circuit constituting the temperature compensation unit 6 (S12). ).

  Note that the processing of S11 and S12 can be executed a plurality of times by acquiring a plurality of selection information from the input terminal 7. That is, in the normal operation mode, the selection information acquisition unit 62 can arbitrarily select one temperature frequency characteristic from a plurality of temperature frequency characteristics regardless of whether the temperature frequency characteristic is already selected. In this way, when the temperature compensated oscillator 100 is mounted on a substrate such as a prototype and an operation test is performed, the operation test is performed for each of the plurality of temperature frequency characteristics without removing the temperature compensated oscillator 100. Can do.

  Subsequently, the control voltage output unit 64 corresponds to the ambient temperature detected by the temperature detection unit 3 based on a constant cubic function stored in the EEPROM 4 in association with the temperature frequency characteristic selected by the selection unit 63. A control voltage is output (S13). Specifically, the control voltage output unit 64 obtains the address of the EEPROM 4 in which a constant corresponding to information indicating one temperature frequency characteristic is stored, from a register provided in a circuit constituting the temperature compensation unit 6. . Subsequently, the control voltage output unit 64 acquires a constant corresponding to the address from the EEPROM 4. Subsequently, the control voltage output unit 64 calculates a cubic function based on the temperature detected by the temperature detection unit 3 and the acquired constant, and outputs a control voltage corresponding to the ambient temperature.

  Thereby, when the operation mode is the normal operation mode, the control voltage output unit 64 is a cubic function of a constant corresponding to one of a plurality of constants corresponding to the plurality of temperature frequency characteristics stored in the EEPROM 4. A control voltage is generated based on When the control voltage is output, the temperature compensated oscillator 100 oscillates at a frequency satisfying the selected temperature frequency characteristic (S14).

  As described above, according to the present embodiment, the temperature compensated oscillator 100 is connected to the oscillation circuit 1 including the crystal resonator 11, the temperature detection unit 3 that detects the ambient temperature, and the oscillation circuit 1, and has an impedance according to the control voltage. The constant of a cubic function indicating the relationship between the ambient temperature and the control voltage is stored in association with the variable impedance element 2 that changes the oscillation frequency of the oscillation circuit and the temperature frequency characteristics of the temperature compensated oscillator 100. Temperature detection based on EEPROM 4, selection unit 63 that selects one temperature frequency characteristic from a plurality of temperature frequency characteristics, and a constant cubic function stored in EEPROM 4 in association with the temperature frequency characteristic selected by the selection unit A control voltage output unit 64 that outputs a control voltage corresponding to the ambient temperature detected by the unit 3. Thus, the temperature compensated oscillator 100 can operate by selecting one temperature frequency characteristic from a plurality of temperature frequency characteristics. Therefore, the user of the temperature compensated oscillator 100 can obtain an oscillation signal having a desired temperature frequency characteristic.

  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 will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Oscillator circuit, 2 ... Variable impedance element, 3 ... Temperature detection part, 4 ... EEPROM, 6 ... Temperature compensation part, 11 ... Crystal oscillator, 30 ... Computer 40 ... Frequency measuring device, 61 ... Mode selection unit, 62 ... Selection information acquisition unit, 63 ... Selection unit, 64 ... Control voltage output unit, 100 ... Temperature compensated oscillator

Claims (5)

A temperature compensated oscillator that changes the oscillation frequency according to the control voltage,
A temperature detector for detecting the ambient temperature;
An oscillation circuit including a vibrator;
A variable impedance element that is provided in the oscillation circuit and changes an oscillation frequency according to the control voltage to change an oscillation frequency of the oscillation circuit;
A storage unit that stores a constant of a nonlinear function indicating a relationship between the ambient temperature and the control voltage in association with a plurality of temperature frequency characteristics of the temperature compensated oscillator;
A selection unit for selecting one temperature frequency characteristic from the plurality of temperature frequency characteristics;
The control voltage corresponding to the ambient temperature detected by the temperature detection unit is output based on the nonlinear function of the constant stored in the storage unit in association with the temperature frequency characteristic selected by the selection unit. A control voltage output unit to
A temperature compensated oscillator comprising: The operation mode of the temperature compensated oscillator is different from the adjustment mode in which the control voltage output unit outputs the control voltage based on the adjustment constant, and the control voltage output unit based on the constant is different from the adjustment mode. A mode selection unit for selecting from a normal operation mode for outputting a control voltage;
The storage unit temporarily stores a constant for adjusting the nonlinear function,
The control voltage output unit outputs the control voltage corresponding to the ambient temperature based on the nonlinear function of the adjustment constant stored in the storage unit when the operation mode is the adjustment mode, When the operation mode is the normal operation mode, the control voltage corresponding to the ambient temperature is generated based on the nonlinear function of the constant stored in the storage unit.
The temperature compensated oscillator according to claim 1. A selection information acquisition unit for acquiring selection information for selecting one temperature frequency characteristic from the plurality of temperature frequency characteristics;
The selection unit selects one temperature frequency characteristic from the plurality of temperature frequency characteristics based on the selection information;
The temperature compensated oscillator according to claim 1 or 2. A method of manufacturing a temperature compensated oscillator including an oscillation circuit that changes an oscillation frequency according to a control voltage,
Storing a plurality of non-linear function adjustment constants for outputting the control voltage in a storage unit;
Adjusting the ambient temperature of the temperature compensated oscillator;
At the ambient temperature, the oscillation frequency when the control voltage is output based on a nonlinear function to which each of the plurality of adjustment constants stored in the storage unit is applied is measured for each of the plurality of adjustment constants. Process,
The control corresponding to each of a plurality of temperature frequency characteristics of the oscillation circuit based on the oscillation frequency measured based on each of the adjustment constants and the ambient temperature when the oscillation frequency was measured. Calculating a plurality of constants for generating a voltage;
Storing the plurality of calculated constants in the storage unit in association with a plurality of the temperature frequency characteristics;
A method for manufacturing a temperature compensated oscillator. In the step of calculating the constant,
Obtaining a plurality of relationship information indicating the relationship between the ambient temperature and the oscillation frequency at the ambient temperature;
Calculating the constant based on the plurality of obtained relationship information, the oscillation frequency measured based on the plurality of adjustment constants, and the ambient temperature when the oscillation frequency is measured;
The manufacturing method of the temperature compensation oscillator of Claim 4.

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