JP6707366B2 - Oscillator - Google Patents

Description

The present invention relates to an oscillation including a PLL (Phase Locked Loop) circuit unit for generating an oscillation output according to a frequency setting value based on a clock signal generated while adjusting the temperature of an atmosphere in which a crystal unit is placed. Regarding the device.

As an oscillator using a crystal oscillator, OCXO (Oven Controlled Xtal Oscillator), which is an oscillator with a thermostatic chamber, heats the atmosphere in which the crystal oscillator is placed to a constant temperature by a heater, and the temperature of the crystal oscillator is external. It is constructed so that it is not affected by temperature changes.
For example, in Patent Document 1, as a technique aiming at high accuracy in temperature control of a heater, two crystal oscillators are used as a temperature detection unit, and a temperature detection value calculated using a frequency difference between the two crystal oscillators. There is described an OCXO that obtains a signal value corresponding to and controls the output of the heater based on this signal value (Patent Document 1).

As described above, even in the OCXO having the function of keeping the temperature of the atmosphere in which the crystal unit is placed (atmosphere temperature) constant, a circuit (eg, crystal unit It is difficult to sufficiently control the temperature of the integrated circuit that constitutes the oscillator circuit) due to structural restrictions. Therefore, the temperature of the atmosphere in which the component is placed may change subtly with changes in the external temperature. At this time, if there is a temperature-frequency characteristic in the component, the frequency (output frequency) of the frequency signal (oscillation output) output from the OCXO may deviate from the frequency setting value.

Therefore, the OCXO described in Patent Document 1 linearly approximates the relationship between the ambient temperature and the output frequency of the OCXO (specifically, the frequency stability [ppb] indicating the frequency deviation from the frequency setting value) and outputs the output. It also has the function of a TCXO (Temperature Compensated Xtal Oscillator) that corrects the frequency setting value of the OCXO based on the detected temperature value of the ambient temperature so that the frequency becomes constant.
However, the correction using the linear approximation relationship described above is a correction that focuses only on the influence of the temperature change on the crystal unit, and thus there is a limit to the improvement of frequency stability.

Here, in Patent Document 2, a thermistor is adopted as a temperature detection unit, and a crystal oscillator is used by increasing or decreasing a current flowing through a heating element connected to a power transistor by utilizing a resistance change of the thermistor accompanying a change in ambient temperature. A temperature control circuit for a crystal oscillator that maintains a constant temperature is described. However, Patent Document 2 does not describe a technique for keeping the output frequency constant when the temperature of the atmosphere in which the crystal oscillator is placed changes while the temperature is controlled by the temperature control circuit for the crystal oscillator.

JP-A-2014-68316: Claim 1, paragraphs 0011, 0034, 0043, FIG. JP-A-11-317622: Claim 1, paragraphs 0011 to 0012, FIG.

The present invention has been made under such circumstances, and an object thereof is to detect the temperature of the atmosphere in which the crystal unit is placed and control the heating unit based on the detected temperature value to control the temperature of the atmosphere. It is an object of the present invention to provide an oscillation device capable of obtaining an oscillation output having a high frequency stability, in the oscillation device having a constant frequency.

An oscillation device according to a first aspect of the present invention is an oscillation device including a PLL circuit unit for generating an oscillation output according to a frequency set value, using an output of an oscillation circuit for clock output connected to a crystal oscillator as a clock signal. A device,
A heating unit for stabilizing the temperature of the atmosphere in which the crystal unit is placed;
A temperature detection unit for detecting the temperature of the atmosphere in which the crystal unit is placed,
Control for extracting a deviation between the temperature setting value of the heating unit and the temperature detection value detected by the temperature detection unit, and outputting an output control value corresponding to the deviation for adjusting the output of the heating unit A value acquisition section,
To the heating unit, a control power supply unit that supplies control power that linearly corresponds to the output control value,
In order to correct the frequency deviation from the frequency setting value of the frequency of the oscillation output due to the change of the clock signal due to the temperature of the atmosphere being different from the temperature setting value of the heating unit, the control value A frequency correction unit that acquires a frequency correction value linearly corresponding to the output control value output from the acquisition unit, and subtracts the frequency correction value from the frequency setting value, and
The heating unit,
Resistance heating part,
A control terminal is provided that is connected to the resistance heating section and is supplied with control power supplied from the control power supply section, and controls a current flowing through the resistance heating section based on the control power. A current control element,
Resistance value changes nonlinearly in accordance with the temperature prior Symbol atmosphere, one end comprises a thermistor provided in a position connected to the connection point side of the control end of the control power supply unit and the current control element, And a correction circuit for correcting the control power supplied to the control end in response to a non-linear change in the frequency of the oscillation output with respect to a change in the temperature of the atmosphere.
The oscillator according to the second aspect of the invention includes a PLL circuit section for generating an oscillation output according to a frequency set value, using the output of the oscillation circuit for clock output connected to the crystal oscillator as a clock signal. An oscillating device,
A heating unit for stabilizing the temperature of the atmosphere in which the crystal unit is placed;
A temperature detection unit for detecting the temperature of the atmosphere in which the crystal unit is placed,
Control for extracting a deviation between the temperature setting value of the heating unit and the temperature detection value detected by the temperature detection unit, and outputting an output control value corresponding to the deviation for adjusting the output of the heating unit A value acquisition section,
To the heating unit, a control power supply unit that supplies control power that linearly corresponds to the output control value,
In order to correct the frequency deviation from the frequency setting value of the frequency of the oscillation output due to the change of the clock signal due to the temperature of the atmosphere being different from the temperature setting value of the heating unit, the control value A frequency correction unit that acquires a frequency correction value linearly corresponding to the output control value output from the acquisition unit, and subtracts the frequency correction value from the frequency setting value, and
The heating unit,
Resistance heating part,
It is constituted by either a pnp-type bipolar transistor or an npn-type bipolar transistor, which is connected to the resistance heating section and has a control terminal to which the control power supplied from the control power supply section is supplied, A current control element for controlling a current flowing through the resistance heating portion based on the control power;
The resistance value changes non-linearly according to the temperature of the atmosphere, one end of which is connected to the control power supply unit side and the other end of which is provided at a position connected to the control end side of the current control element. A negative characteristic thermistor or a CTR (Critical Temperature Resistor) thermistor, and corrects the control power supplied to the control end in response to a non-linear change in the frequency of the oscillation output with respect to a change in the temperature of the atmosphere. And a correction circuit for

The oscillator described above may have the following features.
(A) In the first and second aspects of the invention, the temperature detecting unit is configured by providing a first crystal unit provided with a first electrode on a crystal piece and a second electrode provided on the crystal piece. The second crystal oscillator, the first oscillator circuit and the second oscillator circuit respectively connected to the first crystal oscillator and the second crystal oscillator, and the oscillation frequency of the first oscillator circuit is f1. , F1r is the oscillation frequency of the first oscillation circuit at the reference temperature, f2 is the oscillation frequency of the second oscillation circuit, and f2r is the oscillation frequency of the second oscillation circuit at the reference temperature, which corresponds to the difference between f1 and f1r. And a value corresponding to the difference value between f2 and f2r, as a temperature detection value.
At this time, the oscillator circuit for clock output and one of the first oscillator circuit and the second oscillator circuit are shared.
(B) In the first invention, the current control element is selected from a control element group including a p-type field effect transistor, an n-type field effect transistor, a pnp-type bipolar transistor, and an npn-type bipolar transistor. Be something. The thermistor is selected from a thermistor group including a negative characteristic thermistor, a positive characteristic thermistor, and a CTR (Critical Temperature Resistor) thermistor.
(C) In the first invention, the current control element, the gate side and a control terminal, a p-type field effect transistor of which the resistance heating unit to the source side is connected, before Symbol correction circuit, the control a connection end between the control power supply unit which is connected with respect to the common node of the end side, and the driving power supply terminal of power for driving is supplied of the field effect transistor, and a ground terminal, these control end And a connection end, a control end and a driving power supply end, and a resistor provided between the control end and a ground end, respectively, and the other end of the thermistor is connected to the ground end side. It must be a negative characteristic thermistor installed at the specified position . At this time, the non-linear change of the frequency of the oscillation output with respect to the change of the temperature of the atmosphere is a change in which the frequency of the oscillation output decreases as the temperature of the atmosphere rises, and exhibits a downward convex curve shape. The frequency correction unit decreases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction. Alternatively, the non-linear change in the frequency of the oscillation output with respect to the change in the temperature of the atmosphere is a change in which the frequency of the oscillation output rises as the temperature of the atmosphere rises, and which shows a convex curve shape. The frequency correction unit increases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction.
(D) In the first invention, the current control element is a p-type field effect transistor having a gate side as a control end and the resistance heating portion connected to a source side, and the correction circuit has the control end. a connection end between the control power supply unit which is connected with respect to the common node side, the driving power supply terminal of power for driving is supplied of the field effect transistor, and the ground terminal, and these control end A resistor provided between the control end and the drive power supply end, and between the control end and the ground end, respectively, and the other end of the thermistor is connected to the drive power supply end side. It must be a negative characteristic thermistor installed at the position to be connected . At this time, the non-linear change of the frequency of the oscillation output with respect to the change of the temperature of the atmosphere is a change in which the frequency of the oscillation output decreases as the temperature of the atmosphere rises, and exhibits a downward convex curve shape. The frequency correction unit decreases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction. Alternatively, the non-linear change in the frequency of the oscillation output with respect to the change in the temperature of the atmosphere is a change in which the frequency of the oscillation output rises as the temperature of the atmosphere rises, and which shows a convex curve shape. The frequency correction unit increases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction.

According to the present invention, in obtaining an oscillation output from an oscillation device that uses a clock signal obtained by oscillating a crystal unit, the difference between the temperature of the atmosphere in which the crystal unit is placed and its temperature set value is calculated. The corresponding output control value is used to control the output of the heating unit for keeping the temperature of the atmosphere constant and to correct the frequency of the oscillation output caused by the change of the ambient temperature. Further, when the correspondence relationship between the ambient temperature and the oscillation output frequency is non-linear, a correction circuit for changing the response of the heating unit side to the output control value in a non-linear manner according to the correspondence relationship of the oscillation output side is provided. ing. As a result, when the ambient temperature changes, the response on the heating section side is adjusted so that the output control value suitable for correcting the frequency of the oscillation output is adjusted. Can be done accurately.

It is a block diagram showing the whole oscillation device composition concerning an embodiment. It is a temperature characteristic figure which shows the relationship between the output value of the frequency difference detection part provided in the said oscillation device, and temperature. It is a vertical side view which shows the schematic internal structure of the said oscillation device. It is a circuit diagram which concerns on the comparative example of the heater circuit for making the temperature of the atmosphere in the said oscillation device constant. It is a characteristic view which shows the relationship between the output control value from the loop filter provided in the said oscillator, a heater control voltage, and the temperature detection value of an atmosphere. It is a schematic diagram which shows the correction method of the output frequency in a comparative example. It is a circuit diagram which shows the 1st structural example of the heater circuit which concerns on embodiment. It is a characteristic view of an NTC type thermistor provided in the heater circuit according to the first configuration example. It is an atmosphere temperature-heater control voltage characteristic diagram which concerns on a 1st structural example. It is a schematic diagram which shows the correction method of the output frequency of the oscillation device provided with the heater circuit which concerns on a 1st structural example. It is a circuit diagram which shows the 2nd structural example of the heater circuit which concerns on embodiment. It is an atmospheric temperature-heater control voltage characteristic diagram which concerns on a 2nd structural example. It is a schematic diagram which shows the other example of the correction method of the output frequency in a comparative example. It is a schematic diagram which shows the correction method of the output frequency of the oscillation device provided with the heater circuit which concerns on a 2nd structural example. It is explanatory drawing which shows the example of the other output frequency characteristic with respect to the change of ambient temperature. It is a characteristic view which shows the correspondence of a heater control voltage and a frequency correction value which corrects a frequency set value. It is a characteristic view of a CTR type and a PCT type thermistor. It is a 1st explanatory view which shows the variation of a heater circuit, and its characteristic. It is a 2nd explanatory view which shows the variation of a heater circuit, and its characteristic. It is the 3rd explanatory view showing the variation of a heater circuit, and its characteristic. It is the 4th explanatory view showing the variation of a heater circuit, and its characteristic.

FIG. 1 is a block diagram showing an entire oscillating device according to an embodiment of the present invention. This oscillator is configured as a frequency synthesizer that generates a frequency signal (oscillation output) having a frequency according to a frequency set value.
The oscillator includes a first crystal oscillator 10, a second crystal oscillator 20, and a first oscillator circuit 1 and a second oscillator circuit 2 that oscillate these crystal oscillators. The first oscillating circuit 1 and the second oscillating circuit 2 are composed of, for example, Colpitts type oscillating circuits.

The outputs of the first oscillator circuit 1 and the second oscillator circuit 2 are input to the frequency difference detection unit 31. Further, a first addition unit 32, a heater control unit 33, and a D/A conversion unit 34 are provided at the subsequent stage of the frequency difference detection unit 31, and the output of the D/A conversion unit 34 is the first and second outputs. It is input to the heater circuit 4 which is a heating unit provided in the vicinity of the crystal oscillators 10 and 20.

In the following description, the frequency signal obtained by oscillating the first crystal oscillator 10 by the first oscillator circuit 1 is f1, and the second oscillator circuit 2 oscillates the second crystal oscillator 20. The obtained frequency signal is defined as f2 (for convenience of description, f1 and f2 may indicate the frequency of each frequency signal).
The frequency signal f1 from the first oscillation circuit 1 is phase-compared with a frequency signal obtained from a VCXO (Voltage Controlled Xtal Oscillator) 62, which will be described later, provided in the PLL circuit unit 6. It is used as a clock signal when generating a reference frequency signal. Further, the frequency signal f1 is also used for the purpose of detecting the temperature of the atmosphere in which the crystal oscillators 10 and 20 are placed (the temperature inside the container 71, which will be described later, also referred to as “atmosphere temperature”). On the other hand, the frequency signal f2 from the second oscillator circuit 2 is used only for the purpose of detecting the ambient temperature in which the crystal oscillators 10 and 20 are placed.

First, a method of temperature detection using the frequency signals f1 and f2 will be described. The frequency signal f1 from the first oscillating circuit 1 and the frequency signal f2 from the second oscillating circuit 2 are input to the frequency difference detecting unit 31, and ΔF which is a value corresponding to the frequency difference f1-f2 is calculated. Schematically, the frequency difference detection unit 31 is a circuit unit for extracting f2-f1-Δfr, which is the difference between f1 and f2 and Δfr. Δfr is the difference between f1 (f1r) and f2 (f2r) at the reference temperature, for example, 25° C. An example of the difference between f1 and f2 is several MHz. The frequency difference detection unit 31 calculates ΔF, which is the difference between the value corresponding to the difference between f1 and f2 and the value corresponding to the difference between f1 and f2 at the reference temperature, for example, 25°C. In the case of this embodiment, more specifically, the value obtained by the frequency difference detection unit 31 is {(f2-f1)/f1}-{(f2r-f1r)/f1r}.

FIG. 2 shows the relationship between the digital output value of the frequency difference detection unit 31 and the temperature, and it can be seen that the output has a linear relationship with the temperature. Therefore, it can be said that the output value (digital value) of the frequency difference detection unit 3 corresponds to the temperature detection value of the atmosphere in which the crystal oscillators 10 and 20 are placed. Therefore, the crystal units 10 and 20, the oscillation circuits 1 and 2, and the frequency difference detection unit 31 correspond to a temperature detection unit for obtaining the temperature detection value.

Returning to FIG. 1, the first addition unit 32 is provided at the subsequent stage of the frequency difference detection unit 31. A value (hereinafter, referred to as “temperature set value”) corresponding to the set value (for example, 80° C.) of the ambient temperature acquired from the outside, is calculated in the first addition section 32 by the frequency difference detection section 31. The difference value from the detected temperature value ΔF (deviation between the set temperature value and the detected temperature value) is output to the heater control unit 33 in the subsequent stage.

The heater control unit 33 outputs an output control value for adjusting the output of the heater circuit 4 to the D/A conversion unit 34 in the subsequent stage. The heater control unit 33 calculates an output control value for adjusting the output of the heater circuit 4 so that the deviation calculated by the first adding unit 32 becomes zero. As an example, the heater control unit 33 may be configured by a loop filter that time-integrates the deviation and outputs a value corresponding to the integrated value as an output control value. The heater control unit 33 that calculates the output control value for adjusting the output of the heater circuit 4 corresponds to the control value acquisition unit of this example.

The D/A converter 34 converts the digital value of the output control value output from the heater controller 33 into an analog signal. The D/A converter 34 outputs to the heater circuit 4 control power based on the output control value acquired from the heater controller 33.

The heater circuit 4 provided in the vicinity of the crystal oscillators 10 and 20 has its output adjusted according to the control power output from the D/A converter 34. The detailed configuration of the heater circuit 4 will be described later.

Next, the PLL circuit unit 6 that uses the frequency signal f1 obtained from the first oscillation circuit 1 as a clock signal and outputs a frequency signal having a stable frequency even when the ambient temperature changes will be described. The PLL circuit unit 6 includes a VCXO control unit 61 including a DDS (Direct Digital Synthesizer) circuit unit (not shown), a phase comparison unit, a charge pump unit, and a loop filter, and a crystal (not shown) that oscillates a frequency signal. And a VCXO 62 provided with a vibrator. Further, the VCXO controller 61 may be provided with a frequency divider that divides the frequency signal obtained from the VCXO 62.

For the VCXO controller 61, frequency setting is performed using a frequency setting value input from the outside. The DDS circuit section provided in the VCXO control section 61 uses the frequency signal f1 output from the first oscillating circuit 1 as an operation clock (clock signal), and based on the frequency set value, an amplitude from a waveform table (not shown). The data is read and a reference frequency signal corresponding to the frequency setting value is generated.

On the other hand, the frequency signal obtained by oscillating the VCXO 62 is frequency-divided as necessary, and then phase-compared with the reference frequency signal in the phase comparison unit, and the signal corresponding to the phase difference is converted into an analog signal in the charge pump unit. Is input to the loop filter. In the loop filter, the analog-converted phase difference is integrated and used as the control voltage of the VCXO 62.

With the configuration described above, frequency control is performed so that the frequency of the frequency signal obtained by oscillating the crystal oscillator in the VCXO 62 approaches the frequency of the reference frequency signal generated in the DDS circuit unit based on the frequency setting value. Is executed, and a frequency signal having a stable output frequency fo is output from the VCXO 62.

In the above-described oscillation device, the temperature detection unit (the crystal oscillators 10 and 20, the oscillation circuits 1 and 2 and the frequency difference detection unit 31) oscillates a clock signal for operating the VCXO control unit 61 of the PLL circuit unit 6. The OCXO that detects the temperature of the atmosphere in which the first crystal unit 10 is placed and executes the output adjustment of the heater circuit 4 that adjusts the ambient temperature based on the detection result (temperature detection value).

As shown in the schematic vertical cross-sectional side view in FIG. 3, the oscillator, which is an OCXO, includes a crystal substrate 10, 20 on the upper surface side of the printed circuit board 72 housed in a container 71, and An integrated circuit unit 300 in which a circuit for performing digital processing including the oscillation circuits 1 and 2 and the frequency difference detection unit 31 described above is integrated into one chip, and a crystal oscillator 621 of the VCXO 62 in the PLL circuit unit 6 are provided. There is. Further, on the lower surface side of the printed board 72, a heater circuit 4 is provided, for example, at a position facing the crystal oscillators 10 and 20, and the heat generated by the heater circuit 4 sets the temperature of the atmosphere in which the crystal oscillators 10 and 20 are placed. It is maintained at the temperature corresponding to the value. In the example shown in FIG. 3, the temperature of the atmosphere in which the crystal oscillators 10 and 20 are placed corresponds to the temperature in the space of the container 71.

Further, the present oscillator is also configured as a TCXO that corrects the frequency setting value based on the temperature detection value. As a result, the frequency stabilization by the heater circuit 4 of the OCXO and the frequency stabilization by the frequency correction based on the temperature detection value of the ambient temperature are taken, and the frequency can be stabilized with high accuracy.

As shown in FIG. 1, as a configuration related to TCXO, the oscillator includes a second addition unit 52 that adds a frequency correction value to a frequency setting value of the PLL circuit unit 6, and a second addition unit 52. A correction value acquisition unit 51 that outputs a frequency correction value is provided. The correction value acquisition unit 51 acquires from the heater control unit 33 the output control value calculated based on the detection result of the atmosphere in which the first crystal unit 10 is placed, and based on this output control value, the frequency correction value is acquired. It has gained.
The correction value acquisition unit 51 and the second addition unit 52 correspond to the frequency correction unit of the present oscillation device.

Here, in obtaining the frequency correction value by the correction value obtaining unit 51, the reason why the output control value for adjusting the output of the heater circuit 4 is used and the calculation method thereof are shown in FIGS. It will be explained with reference to FIG.
First, in order to facilitate understanding of the configuration and operation of the heater circuit 4 according to the embodiment, a heater circuit 4′ according to a comparative example shown in FIG. 4 is used to adjust its operation and output of the heater circuit 4′. The characteristics of the output control value used will be described.

The heater circuit 4′ includes a resistance circuit 402 in which a plurality of resistors are connected in parallel, and a current control element that controls a current flowing through the resistance circuit 402, for example, a p-type field effect transistor (FET) 401. With. Further, since the FET 401 generates heat when a current flows, it also functions as a resistance heating portion of the heater circuit 4′ together with the resistance circuit 402.
The source side of the FET 401 is connected to the heater power supply for supplying the electric power for the heater through the resistance circuit 402 described above, while the terminal on the drain side is grounded.

On the other hand, the drive power source of the FET 401 is connected to the gate side terminal (control end) A of the FET 401, and the control power output from the D/A conversion unit 34 is supplied with respect to the power supplied from the drive power source. Are overlaid. Further, the terminal A on the gate side of the FET 401 is grounded. Between the terminal A on the gate side of the FET 401 and the connection end to which the power for control output from the D/A converter 34 is supplied, the terminal A on the gate side and the power for driving the FET 401 are also supplied. The resistors R1 to R3, which are respectively provided between the terminal A on the gate side and the grounded end which is also grounded, are resistors that determine the driving operation point of the FET 401.

In the above-mentioned heater circuit 4', when the control power supplied from the D/A conversion unit 34 increases when the voltage on the heater power supply side and the drive power supply side are constant, the FET 401 is proportional to the power. The applied voltage (heater control voltage) becomes high. In the p-type FET 401, when the heater control voltage increases, the current flowing between the source and the drain decreases, and the power consumption of the resistance circuit 402 and the FET 401 decreases (the output of the heater circuit 4′ decreases).
On the contrary, when the control power supplied from the D/A converter 34 side decreases, the heater control voltage decreases in proportion to the power, and the current flowing between the source and the drain increases to increase the resistance. The power consumption of the circuit 402 and the FET 401 increases (the output of the heater circuit 4′ increases).

Summarizing the above operations, in the heater circuit 4′ shown in FIG. 4, the output becomes smaller as the control power is increased, and the output becomes larger as the control power is reduced.
It is necessary to reduce the output of the heater circuit 4′ when the temperature of the atmosphere in which the first crystal unit 10 is placed rises, and it is necessary to increase the output when the ambient temperature decreases. It was when I did. Therefore, the temperature detection value and the output output from the heater control unit 33 are set so that the control power is increased when the detected temperature value of the ambient temperature is high and the control power is decreased when the detected temperature value is low. The correspondence with the control value may be set.

Based on the above-mentioned correspondence, the heater control voltage applied to the FET 401 can be determined based on the output control value output from the heater control unit 33. FIG. 5 shows the correspondence relationship between the output control value (horizontal axis) output from the heater control unit 33, the detected temperature value of the ambient temperature, and the heater control voltage (vertical axis). As described above, in the heater circuit 4′, the slope of increasing the control power with the increase of the ambient temperature has a positive correlation, whereas the frequency of the heater circuit 4′ increases with the increase of the ambient temperature. The digital output value from the difference detection unit 31 is small, and the slope has a negative correspondence relationship (FIG. 2). Therefore, in order to realize the correspondence relationship shown in FIG. 5, for example, the heater control unit 33 outputs the output control value, which is the digital value input from the first addition unit 32, to the D/A conversion unit 34, the output control value being inverted. ..

The D/A conversion unit 34 adjusts the heater control voltage by outputting control power obtained by multiplying the output control value of the heater control unit 33, which has a linear relationship with the ambient temperature, by a predetermined gain. To do. From this viewpoint, the D/A conversion unit 34 corresponds to a control power supply unit that supplies the control power linearly corresponding to the output control value to the heater circuit 4.

According to the relationship shown in FIG. 5, the output control value output from the heater control unit 33 corresponds to the temperature detection value of the atmosphere in which the oscillator is placed.
On the other hand, the PLL circuit unit 6 that uses the frequency signal f1 obtained from the first oscillation circuit 1 as a clock signal deviates from the frequency setting value when the ambient temperature changes and the frequency of the clock signal changes. The frequency signal of the output frequency is output.

For example, FIG. 6A shows a change in the output frequency fo with respect to the ambient temperature (output frequency characteristic). As shown in the figure, as the ambient temperature deviates from the set temperature corresponding to the temperature set value, the deviation amount of the output frequency from the frequency set value tends to increase. Further, in the example shown in FIG. 6A, the output frequency tends to increase as the ambient temperature shifts in a direction lower than the set temperature, and the output frequency tends to decrease as the ambient temperature shifts to a higher temperature. Furthermore, in this example, the rate of change of the frequency is large on the low temperature side and small on the high temperature side with respect to the change of the ambient temperature, that is, the “falling tendency and It has a "convex" output frequency characteristic.
The horizontal axis of FIG. 6 represents the temperature of the atmosphere in which the oscillator is placed, and the vertical axis represents the frequency stability (the difference value between the output frequency fo of the PLL circuit unit 6 and the frequency setting value fos is set to the frequency setting value fos). Values (ppb units)) (the same applies to FIGS. 10 and 13 to 15).

Here, it is considered that the change in the frequency setting value and the change in the output frequency are in a substantially proportional relationship at each ambient temperature. At this time, if the output frequency from the PLL circuit unit 6 is “fo=fos+Δfo” as a result of inputting the predetermined frequency setting value fos, the frequency setting value is corrected using the correction value Δfo, and a new frequency is set. By inputting “fos′=fos−Δfo” as the set value, an output frequency closer to the frequency set value fos can be obtained.

For example, the broken line shown in FIG. 6A shows the relationship between the atmospheric temperature and the frequency stability obtained by approximating the output frequency characteristic shown by the solid line with a straight line. As shown in FIG. 6B, the correction amount is subtracted from the frequency setting value by using the amount of deviation of the correspondence relationship from the state where the output frequency matches the frequency setting value (frequency stability is 0 ppb) as the correction value. It is possible to improve the output frequency characteristic.

Here, the correspondence relationship shown by the broken line in FIG. 6A in which the correction value linearly decreases with the increase of the ambient temperature is the detected temperature value of the atmosphere shown by the solid line in FIG. It is nothing more than an inversion of the slope of the correspondence with the output control value.
Therefore, as shown in FIG. 1, the output control value output from the heater control unit 33 is used, and the correction value acquisition unit 51 multiplies the gain by a predetermined gain to obtain the frequency correction value shown by the broken line in FIG. 6A. A straight line of (frequency correction value linearly corresponding to the output control value) can be obtained. In other words, the heater control voltage (heater control power) supplied to the heater circuit 4′ and the frequency correction value output from the correction value acquisition unit 51 have a negative correspondence relationship (described later). See FIG. 16( a ).

The frequency correction value acquired by the correction value acquisition unit 51 is subtracted from the frequency setting value by the second adding unit 52, and the PLL circuit unit 6 is operated based on the corrected frequency setting value thus obtained. As a result, as shown in FIG. 6B, it is possible to obtain an output frequency characteristic having good frequency stability with respect to a change in ambient temperature, as compared with the output frequency characteristic shown in FIG. 6A. The correction value acquisition unit 51 and the second addition unit 52 related to the TCXO function described above correspond to the frequency correction unit of the oscillator.

As described above, since the oscillator configured as the OCXO that controls the temperature of the first crystal unit 10 by the heater circuit 4′ also has the function of TCXO, the first crystal described in the background art is described. It is possible to reduce the influence of the temperature change of the atmosphere in which the oscillating device is placed on circuits other than the oscillator 10 (for example, the first oscillating circuit 1) and output a frequency signal with a stable output frequency.

However, as shown in FIG. 6A, the actual output frequency characteristic of the PLL circuit unit 6 may exhibit a curved (non-linear) shape with respect to changes in the ambient temperature. Here, as the first crystal unit 10, in many cases, a unit having a substantially flat temperature-frequency characteristic within a temperature range in which the heater circuit 4'is controlled is adopted. Even in such a case, the reason why the output frequency characteristic shows a curved shape is that the influence is large because the temperature-frequency characteristic of the circuits other than the above-mentioned first crystal unit 10 shows a curvilinear change. Conceivable.

At this time, when a correction value (correction value straight line) that linearly changes with respect to the ambient temperature as shown by the broken line in FIG. 6A is used, the output frequency characteristic of the output frequency characteristic is corrected even after the correction. The deviation width due to the curvature remains (FIG. 6(b)).
In order to reduce such a deviation width, as shown by a broken line in FIG. 10A, a correction value curve having a curved shape that curves in accordance with a change in the ambient temperature along with a change in the actual output frequency characteristic. Can be used.

However, in the heater circuit 4′ according to the comparative example shown in FIG. 4, as described with reference to FIG. 5, the heater control voltage applied to the FET 401 causes a change in ambient temperature (change in temperature detection value). Changes linearly accordingly. Therefore, the output control value used when acquiring the correction value can only obtain a relationship that linearly changes with respect to the temperature change, and cannot obtain the correction value curve shown by the broken line in FIG. ..

Therefore, the oscillator according to the embodiment of the present invention includes the heater circuit 4 having a special configuration shown in FIG. In the heater circuit 4 shown in FIG. 7, the same components as those of the heater circuit 4′ according to the comparative example described with reference to FIG. 4 are denoted by the same reference numerals as those used in FIG. 4 ( The same in FIG. 11 described later).

In the heater circuit 4 according to the embodiment, the control power output from the D/A conversion unit 34 is superimposed on the power supplied from the driving power supply, and the gate side of the FET 401 is applied as a heater control voltage. An NTC (Negative Temperature Coefficient) type thermistor 403 is provided in series with the resistor R3′ between the terminal A and a ground terminal grounded via the resistor R3′.

As shown in FIG. 8A, the temperature-resistance characteristic of the thermistor 403 shows a downward convex curve shape in which the resistance value decreases as the temperature rises. Therefore, as shown in the enlarged view of FIG. 8B, if the temperature-resistance characteristic of the thermistor 403 within the use range corresponding to the temperature control range by TCXO is used, it is applied to the FET 401 when the ambient temperature changes. The heater control voltage can be changed in a curve (non-linear).

Using the heater circuit 4 provided with the thermistor 403, the correction value curve for correcting the output frequency characteristic, which is a downward convex curve and a downward tendency with respect to an increase in the ambient temperature, shown in FIG. The effect obtained will be described.
For example, when the ambient temperature in which the thermistor 403 is placed becomes high, the resistance on the ground side (combined resistance of the resistor R3′ and the thermistor 403) when viewed from the terminal A on the gate side of the FET 401 decreases. As a result, the heater control voltage applied to the FET 401 is lower than when the thermistor 403 is not provided (when the resistance on the ground side does not change), so the current flowing between the source and drain increases and the resistance circuit The power consumption of the FET 402 and the FET 401 becomes larger (the output of the heater circuit 4 becomes larger).

On the other hand, on the side of the heater control unit 33 provided in the oscillating device, the direction in which the output increase of the heater circuit 4 is suppressed, that is, the direction in which the heater control voltage is increased more than when the thermistor 403 is not provided. Control is activated (solid line in FIG. 9). The solid line in FIG. 9 is a characteristic diagram of the heater control voltage with respect to the ambient temperature in a stable control state, and the two-dot chain line in the figure shows the characteristic when the thermistor 403 is not provided.

At this time, the NTC type thermistor 403 has a characteristic that the rate of change of the resistance value is large on the low temperature side and is small on the high temperature side in the use range shown in FIG. 8B. Reflecting this characteristic, the heater control voltage shown by the solid line in FIG. 9 also has a large change rate on the low temperature side and a small change rate on the high temperature side with respect to the increase in the ambient temperature, that is, the rising tendency, and , An upward convex curve shape characteristic is obtained.

As described above, when the heater circuit 4 shown in FIG. 7 is used, as the ambient temperature rises, the heater control voltage applied to the FET 401 becomes lower. The power for control output from the A converter 34 is increased (FIG. 9).
Here, as indicated by the solid line in FIG. 5, the power for control has a proportional relationship (linear relationship) that increases as the output control value output from the heater control unit 33 increases. Therefore, when the heater control voltage changes along the curve shown by the solid line in FIG. 9, the characteristic of the output control value corresponding to the correction value curve shown by the broken line in FIG. 10A is obtained.

Then, similarly to the comparative example described with reference to FIGS. 4 to 6, the negative proportional relationship (linear relationship) between the output control value and the frequency correction value is used, and the heater control unit 33 at each ambient temperature. The output control value output from the correction value acquisition unit 51 multiplies the output control value by a predetermined gain. As a result, it is possible to obtain a curve of the frequency correction value (frequency correction value linearly corresponding to the output control value) having a downward tendency and a downward convex, which is indicated by a broken line in FIG.

FIG. 10A shows an ideal correction value curve that is substantially parallel to the output frequency characteristic of the PLL circuit unit 6. The shape of the curve is designed such as the arrangement position of the heater circuit 4 in the container 71, the distance of the thermistor 403 from the resistance circuit 402 or the FET 401 which is the resistance heating unit, the heat capacity of the thermistor 403, and the gain to be multiplied by the correction value acquisition unit 51. It can be adjusted by changing the variable.
In addition, in FIG. 10A, in order to facilitate the discrimination between the output frequency characteristic and the correction value curve, these curves are described apart from each other in the vertical direction. In addition, the straight line indicated by the chain double-dashed line in the figure shows, as a reference, a correction value straight line acquired by the correction value acquisition unit 51 when the thermistor 403 is not provided (as described above, various correction values are obtained). Since the design variables have been changed, they do not always match the correction value straight line shown in FIG.

The frequency correction value along the above-mentioned correction value curve is acquired from the correction value acquisition unit 51, the second addition unit 52 subtracts it from the frequency setting value, and the PLL circuit unit 6 operates based on the corrected frequency setting value. Let As a result, as shown in FIG. 10B, it is possible to obtain an output frequency characteristic with a smaller deviation width and better frequency stability than that of FIG. 6B.

Here, the configuration of the heater circuit 4 shown by the broken line in FIG. 10A and capable of obtaining the downwardly convex and downwardly convex frequency correction value curve is not limited to the example shown in FIG. 7.
For example, the heater circuit 4a shown in FIG. 11 has a resistor R2 between the terminal A on the gate side of the FET 401 on which the control power output from the D/A converter 34 is superimposed and the terminal on the drive power source side. 'Is provided with a thermistor 403a in series.

In the above-mentioned heater circuit 4a, for example, when the ambient temperature in which the NTC type thermistor 403a is placed becomes high, the resistance on the drive power source side (the combined resistance of the resistor R2′ and the thermistor 403a when viewed from the terminal A on the gate side of the FET 401). ) Becomes smaller. As a result, the heater control voltage applied to the FET 401 is higher than that in the case where the thermistor 403a is not provided (when the resistance on the drive power source side does not change), so the current flowing between the source and the drain decreases and the resistance The power consumption of the circuit 402 and the FET 401 becomes smaller (the output of the heater circuit 4a becomes smaller).

On the other hand, on the side of the heater control unit 33 provided in the oscillator, the amount of decrease in the heater control voltage is increased in a direction that compensates for the decrease in the output of the heater circuit 4a, that is, in comparison with the case where the thermistor 403a is not provided. Control acts in the direction (solid line in FIG. 12). The solid line in FIG. 12 is a characteristic diagram of the heater control voltage with respect to the ambient temperature in a stable control state, and the chain double-dashed line in FIG. 12 shows the characteristic when the thermistor 403a is not provided. At this time, as the resistance of the thermistor 403a changes along the curve shown in FIG. 8B, the change rate of the resistance value at the low temperature side is large as shown by the solid line in FIG. 12, and the change rate at the high temperature side. The characteristic of the curve shape that becomes smaller is obtained.

Then, as in the case of the heater circuit 4 described with reference to FIGS. 7 to 10, a predetermined gain is set in the correction value acquisition unit 51 with respect to the output control value output from the heater control unit 33 at each ambient temperature. By multiplying it, it is possible to obtain a curve of a frequency correction value (frequency correction value linearly corresponding to the output control value) having a downward tendency and a downward convex shown by a broken line in FIG.

The oscillation device according to the embodiment described above has the following effects. When obtaining an oscillation output from an oscillator that uses a clock signal obtained by oscillating the first crystal unit 10, the deviation between the temperature of the atmosphere in which the first crystal unit 10 is placed and its temperature setting value. Using the output control value corresponding to the minutes, output control of the heating unit for achieving a constant temperature of the atmosphere (for OCXO) and correction of the output frequency due to changes in the ambient temperature (for TCXO) Is used for. When the relationship between the ambient temperature and the output frequency (output frequency characteristic) is non-linear, the thermistor for changing the response of the heater circuits 4, 4a to the output control value in a non-linear manner according to the output frequency characteristic. A correction circuit including 403 and 403a is provided. As a result, the response on the heater circuit 4, 4a side is adjusted so that the output control value suitable for the correction of the output frequency is output when the ambient temperature changes, so that the frequency correction using the output control value is performed. Can be done accurately.

Here, the aspect of the change of the output frequency characteristic with respect to the ambient temperature may draw a curve other than the “downward tendency and convex downward” described with reference to FIG.
For example, as shown in FIG. 13(a), there is a case where the curve tends to rise with an increase in the ambient temperature, and the curve is convex upward .
In this case, when using the oscillator including the heater circuit 4′ according to the comparative example shown in FIG. 4, when the output control value output from the heater control unit 33 is shown in FIG. The correction value acquisition unit 51 multiplies the gains with opposite signs so that the positive and negative signs are opposite. As a result, the correction value straight line indicated by the broken line in FIG. However, even if the correction using this correction value straight line is performed, the deviation width due to the curve of the output frequency characteristic remains as in the example shown in FIG. 6B (FIG. 13). (B)).

Therefore, if the atmospheric temperature-heater control voltage characteristic exhibiting a downwardly declining and convex downward curve shape can be obtained in a vertically symmetrical manner with the example described with reference to FIGS. 6 to 12, FIG. The output frequency characteristic of FIG. 13A can be improved by the same method as the example using the heater control voltage characteristic of the heater circuits 4 and 4a for the output frequency characteristic of FIG. 14A (FIG. 14 and FIG. 10B).
Note that, also in FIG. 14, in order to facilitate the identification of the output frequency characteristic and the correction value curve, these curves are shown separated in the vertical direction for convenience.

Further, the change of the output frequency characteristic with respect to the ambient temperature tends to increase with an increase in the ambient temperature as shown in FIG. 15(a) and has a downwardly convex curve, or as shown in FIG. 15(b). It is also possible to envisage a case where the curve tends to decrease with an increase in the ambient temperature, and the curve becomes convex upward.
Further, as the current control element, in addition to the p-type FET 401 described above, the n-type FET 401a, the pnp-type bipolar transistor 401b, and the npn-type bipolar transistor 401c can also be used (hereinafter, the bipolar transistor 401b, 401c is simply referred to as "transistors 401b and 401c"). Further, as for the thermistor 403, in addition to the above-mentioned NTC, a PTC (Positive Temperature Coefficient) type having a temperature-resistance characteristic shown in FIG. 17A and a temperature-resistance characteristic shown in FIG. 17B. There is also a CTR (Critical Temperature Resistor) type that has. These PTC type and CTR type thermistors 403 are also desired within the use range by adjusting the arrangement position of the thermistor 403 on the printed board 72 and adjusting the constants of the resistors R1, R2, R3' on the drive power source side in FIG. The temperature-resistance characteristic exhibiting the curved shape of can be utilized.

The heater control voltage characteristics corresponding to the various output frequency characteristics shown in FIGS. 6A, 13A, 15A, and 15B are shown in FIGS. It can be realized by using the heater circuits 4 and 4a to 4g shown in FIG. 7B (the heater circuits 4 and 4a in FIGS. 18A and 19A are reproduced in FIGS. 7 and 12 respectively). Is). Here, (c) of FIGS. 18 to 21 show atmospheric temperature-heater control power characteristics when the heater circuits 4, 4a to 4g are configured by using the NTC type or CTR type thermistors 403 and 403a to 403g. ((C) of FIG. 18 and (c) of FIG. 19 correspond to the reprints of FIGS. 9 and 12, respectively). On the other hand, (d) of FIGS. 18 to 21 show the ambient temperature-heater control power characteristics when the heater circuits 4, 4a to 4g are configured by using the PTC type thermistors 403 and 403a to 403g. In addition, in each of FIGS. 18 to 21 (c) and (d), the characteristics when the heater circuits 4, 4a to 4g are not provided with the thermistors 403 and 403a to 403g are indicated by chain double-dashed lines. is there.

A simple application example in which these various heater circuits 4, 4a to 4g are used to correct the four types of output frequency characteristics shown in FIGS. 6(a), 13(a), 15(a), and (b) Explained.
As a first application example, in order to obtain a correction value curve for correcting the output frequency characteristic which is a downward convex curve and a downward convex curve shown in FIG. (C), FIG. 19(c), FIG. 20(c), and FIG. 21(c) are used.
With respect to the ambient temperature-heater control power characteristics of FIGS. 18C and 19C, the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is The gain and the like in the heater control unit 33 and the correction value acquisition unit 51 are set so as to be negative (FIG. 16A). Further, for the atmosphere temperature-heater control power characteristics of FIGS. 20C and 21C, the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is. The same setting is performed so that the value becomes positive (FIG. 16B).

As a second application example, in order to obtain a correction value curve for correcting the output frequency characteristic that is an upwardly convex curve and an upwardly convex curve as shown in FIG. (C), FIG. 19(c), FIG. 20(c), and FIG. 21(c) are used, and the heater circuits 4, 4a to 4g that can obtain the ambient temperature-heater control power characteristics are used.
With respect to the ambient temperature-heater control power characteristics of FIGS. 18C and 19C, the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is The gain and the like in the heater control unit 33 and the correction value acquisition unit 51 are set so as to be positive (FIG. 16B). Further, for the atmosphere temperature-heater control power characteristics of FIGS. 20C and 21C, the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is. The same setting is performed so that the value becomes negative (FIG. 16A).

As a third application example, in order to obtain a correction value curve for correcting the output frequency characteristic, which is a curve that has an upward tendency and a downward convex curve as shown in FIG. (D), FIG. 19(d), FIG. 20(d), and FIG. 21(d) are used, and the heater circuits 4, 4a to 4g that can obtain the ambient temperature-heater control power characteristics are used.
Then, for the atmosphere temperature-heater control power characteristics of FIGS. 18D and 19D, the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is The gain and the like in the heater control unit 33 and the correction value acquisition unit 51 are set so as to be positive (FIG. 16B). 20(d) and 21(d), the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is the slope of the heater control power. The same setting is performed so that the value becomes negative (FIG. 16A).

As a fourth application example, in order to obtain a correction value curve for correcting the output frequency characteristic, which is a curve which has a downward tendency and an upward convex curve as shown in FIG. (D), FIG. 19(d), FIG. 20(d), and FIG. 21(d) are used, and the heater circuits 4, 4a to 4g that can obtain the ambient temperature-heater control power characteristics are used.
Then, for the atmosphere temperature-heater control power characteristics of FIGS. 18D and 19D, the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is The gain and the like in the heater control unit 33 and the correction value acquisition unit 51 are set so as to be negative (FIG. 16A). 20(d) and 21(d), the slope of the correspondence relationship between the heater control power and the frequency correction value output from the correction value acquisition unit 51 is the slope of the relationship between the heater control power and the heater control power. The same setting is performed so that the value becomes positive (FIG. 16B).

Further, in the method of obtaining the output control value by the heater control unit 33 which is the control value obtaining unit, the integrated value of the deviation between the temperature set value obtained by using the loop filter and the temperature detection value is used as the output control value. Not limited to cases.
For example, output control of a PI calculation value that is a total value of a proportional calculation value obtained by multiplying the deviation amount by a proportional gain and an integration calculation value obtained by multiplying the time integration value of the deviation amount by an integral gain It may be a value. Further, the proportional calculation value may be adopted as the output control value.

Further, it is not essential to share the first crystal unit 10 and the first oscillation circuit 1 forming the temperature detection unit for outputting the clock signal, and the crystal dedicated to outputting the clock signal is provided in the container 71. A vibrator and an oscillation circuit may be separately provided.
Furthermore, the configuration of the temperature detection unit is not limited to the case where the first and second crystal oscillators 10 and 20, the first and second oscillation circuits 1 and 2, and the frequency difference detection unit 31 are provided. Absent. As the temperature detector, for example, a thermistor or a thermocouple may be used.

1 1st oscillation circuit 10 1st crystal oscillator 2 2nd oscillation circuit 20 2nd crystal oscillator 31 frequency difference detection part 32 1st addition part 33 heater control part 34 D/A conversion parts 4, 4a 4'
Heater circuit 401 FET
402 resistance circuits 403, 403a
Thermistor 51 Correction value acquisition unit 52 Second addition unit 6 PLL circuit unit 61 VCXO control unit 62 VCXO

Claims (12)

An oscillation device comprising a PLL circuit unit for generating an oscillation output according to a frequency set value by using an output of an oscillation circuit for clock output connected to a crystal oscillator as a clock signal,
A heating unit for stabilizing the temperature of the atmosphere in which the crystal unit is placed;
A temperature detection unit for detecting the temperature of the atmosphere in which the crystal unit is placed,
Control for extracting a deviation between the temperature setting value of the heating unit and the temperature detection value detected by the temperature detection unit, and outputting an output control value corresponding to the deviation for adjusting the output of the heating unit A value acquisition section,
To the heating unit, a control power supply unit that supplies control power that linearly corresponds to the output control value,
In order to correct the frequency deviation from the frequency setting value of the frequency of the oscillation output due to the change of the clock signal due to the temperature of the atmosphere being different from the temperature setting value of the heating unit, the control value A frequency correction unit that acquires a frequency correction value linearly corresponding to the output control value output from the acquisition unit, and subtracts the frequency correction value from the frequency setting value;
The heating unit,
Resistance heating part,
A control terminal is provided that is connected to the resistance heating section and is supplied with control power supplied from the control power supply section, and controls a current flowing through the resistance heating section based on the control power. A current control element,
Resistance value changes nonlinearly in accordance with the temperature prior Symbol atmosphere, one end comprises a thermistor provided in a position connected to the connection point side of the control end of the control power supply unit and the current control element, A correction circuit for correcting the control power supplied to the control end in response to a non-linear change in the frequency of the oscillation output with respect to a change in the temperature of the atmosphere. .. The current control element is selected from a control element group including a p-type field effect transistor, an n-type field effect transistor, a pnp-type bipolar transistor, and an npn-type bipolar transistor. The oscillator according to Item 1 . 3. The oscillator according to claim 1, wherein the thermistor is selected from a thermistor group consisting of a negative characteristic thermistor, a positive characteristic thermistor, and a CTR (Critical Temperature Resistor) thermistor. The current control element is a p-type field effect transistor having the gate side as a control end and the resistance heating section connected to the source side,
Wherein the correction circuit includes a connection end between the control end of the common connection has been the control power supply unit to the node, the driving power supply terminal of power for driving the field effect transistor is supplied, and a ground terminal, between the connection end to these control terminals, between the drive power supply terminal and the control terminal, and a respective provided resistance between the ground terminal and the control terminal, the thermistor, the other end The oscillator according to claim 1, wherein the oscillator is a negative characteristic thermistor provided at a position connected to the ground end side . The nonlinear change in the frequency of the oscillation output with respect to the change in the temperature of the atmosphere is a change in the frequency of the oscillation output as the temperature of the atmosphere rises, and is a change showing a downward convex curve shape,
The oscillator according to claim 4 , wherein the frequency correction unit decreases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction. .. The non-linear change of the frequency of the oscillation output with respect to the change of the temperature of the atmosphere is a change in which the frequency of the oscillation output rises as the temperature of the atmosphere rises, and is a change showing a convex curve shape.
The oscillator according to claim 4 , wherein the frequency correction unit increases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction. .. The current control element is a p-type field effect transistor having the gate side as a control end and the resistance heating section connected to the source side,
Wherein the correction circuit includes a connection end between the control end of the common connection has been the control power supply unit to the node, the driving power supply terminal of power for driving the field effect transistor is supplied, and a ground terminal, between the connection end to these control terminals, between the drive power supply terminal and the control terminal, and a respective provided resistance between the ground terminal and the control terminal, the thermistor, the other end The oscillator according to claim 1, wherein the oscillator is a negative characteristic thermistor provided at a position connected to the drive power supply end side . The nonlinear change in the frequency of the oscillation output with respect to the change in the temperature of the atmosphere is a change in the frequency of the oscillation output as the temperature of the atmosphere rises, and is a change showing a downward convex curve shape,
The oscillator according to claim 7 , wherein the frequency correction unit decreases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction. .. The non-linear change of the frequency of the oscillation output with respect to the change of the temperature of the atmosphere is a change in which the frequency of the oscillation output rises as the temperature of the atmosphere rises, and is a change showing a convex curve shape.
The oscillation device according to claim 7 , wherein the frequency correction unit increases the frequency correction value when the control power supplied from the control power supply unit to the heating unit changes in an increasing direction. .. An oscillation device comprising a PLL circuit unit for generating an oscillation output according to a frequency set value by using an output of an oscillation circuit for clock output connected to a crystal oscillator as a clock signal,
A heating unit for stabilizing the temperature of the atmosphere in which the crystal unit is placed;
A temperature detection unit for detecting the temperature of the atmosphere in which the crystal unit is placed,
Control for extracting a deviation between the temperature setting value of the heating unit and the temperature detection value detected by the temperature detection unit, and outputting an output control value corresponding to the deviation for adjusting the output of the heating unit A value acquisition section,
To the heating unit, a control power supply unit that supplies control power that linearly corresponds to the output control value,
In order to correct the frequency deviation from the frequency setting value of the frequency of the oscillation output due to the change of the clock signal due to the temperature of the atmosphere being different from the temperature setting value of the heating unit, the control value A frequency correction unit that acquires a frequency correction value linearly corresponding to the output control value output from the acquisition unit, and subtracts the frequency correction value from the frequency setting value;
The heating unit,
Resistance heating part,
Is connected to the resistance heating unit is constituted by one of a bipolar transistor or an npn bipolar transistor of the pnp power for control is supplied Ru comprises a control terminal supplied from the control power supply unit , a current control element for controlling the current flowing through the resistance heating portion based on the power for the control,
Resistance value changes nonlinearly in accordance with the temperature prior Symbol atmosphere, one end is connected to the control power supply unit side, the other end is provided at a position connected to the control end of the current control element In addition, a negative characteristic thermistor or a CTR (Critical Temperature Resistor) thermistor is included, and the control power supplied to the control end is corrected in response to a nonlinear change in the frequency of the oscillation output with respect to a change in the temperature of the atmosphere. An oscillating device, comprising: The temperature detection unit,
A first crystal unit configured by providing a first electrode on a crystal piece;
A second crystal oscillator configured by providing a second electrode on a crystal piece;
A first oscillating circuit and a second oscillating circuit respectively connected to the first crystal unit and the second crystal unit;
The oscillation frequency of the first oscillation circuit is f1, the oscillation frequency of the first oscillation circuit at the reference temperature is f1r, the oscillation frequency of the second oscillation circuit is f2, and the oscillation frequency of the second oscillation circuit at the reference temperature is f2r. Then, a frequency difference detection unit that obtains a value corresponding to a difference value between f1 and f1r and a value corresponding to a difference between f2 and f2r as a temperature detection value is provided. The oscillating device according to any one of claims 1 to 10 . 12. The oscillator according to claim 11 , wherein the oscillator circuit for clock output and one of the first oscillator circuit and the second oscillator circuit are shared.

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