JP2000196359A - Voltage controlled crystal oscillator - Google Patents
Voltage controlled crystal oscillatorInfo
- Publication number
- JP2000196359A JP2000196359A JP10376690A JP37669098A JP2000196359A JP 2000196359 A JP2000196359 A JP 2000196359A JP 10376690 A JP10376690 A JP 10376690A JP 37669098 A JP37669098 A JP 37669098A JP 2000196359 A JP2000196359 A JP 2000196359A
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- Prior art keywords
- voltage
- power supply
- frequency
- dividing resistor
- supply voltage
- Prior art date
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- Oscillators With Electromechanical Resonators (AREA)
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はＰＬＬ（PHASE LOCK
ED LOOP）回路等の基準信号源として用いられる水晶発
振器を産業上の技術分野とし、特に電圧制御型として水
晶発振器の基準周波数を補正する電圧制御水晶発振器
（電圧制御発振器）に関する。The present invention relates to a PLL (PHASE LOCK)
The present invention relates to a crystal oscillator used as a reference signal source for an ED LOOP circuit or the like as an industrial technical field, and particularly to a voltage-controlled crystal oscillator (voltage-controlled oscillator) that corrects a reference frequency of the crystal oscillator as a voltage-controlled type.
【０００２】[0002]
【従来の技術】（発明の背景）ＰＬＬ回路は、概ね、基
準信号源と電圧制御型のＬＣ発振器と位相比較器からな
り、例えば通信機器の局部発振周波数を得る。このよう
なものでは、基準信号源は高安定度を要求されることか
ら、一般に水晶発振器が使用される。近年では、携帯電
話に代表されるように、動的環境下での使用が多いこと
から、基準信号源としての水晶発振器には温度補償型の
ものが適用される。そして、一層の安定度を得るため、
例えば基地局からの信号（便宜的に目的周波数ｆrとす
る）を受信して水晶発振器の基準周波数を補正すること
が行われている。2. Description of the Related Art A PLL circuit generally includes a reference signal source, a voltage control type LC oscillator, and a phase comparator, and obtains, for example, a local oscillation frequency of a communication device. In such a case, since a high stability is required for the reference signal source, a crystal oscillator is generally used. In recent years, a temperature-compensated crystal oscillator is used as a reference signal source because it is frequently used in a dynamic environment as represented by a mobile phone. And to get more stability,
For example, a signal (for convenience, a target frequency fr) from a base station is received to correct the reference frequency of the crystal oscillator.
【０００３】（従来技術の一例）第２図はこの種の一従
来例を説明する電圧制御発振器のブロック図である。電
圧制御発振器は、水晶振動子１をインダクタとして使用
する例えばコルピッツ型の発振回路２と、温度補償回路
３と、電圧可変容量素子としての可変容量ダイオード４
とからなる。これらは、直列に接続し、閉ループ（発振
ループ）を形成する。そして、発振回路２は電源電圧Ｖ
ccを印加されて動作し、発振周波数ｆを出力として得
る。なお、周波数調整回路等は省略してある。(Example of Prior Art) FIG. 2 is a block diagram of a voltage controlled oscillator for explaining a conventional example of this kind. The voltage-controlled oscillator includes, for example, a Colpitts-type oscillation circuit 2 using the crystal unit 1 as an inductor, a temperature compensation circuit 3, and a variable capacitance diode 4 as a voltage variable capacitance element.
Consists of These are connected in series to form a closed loop (oscillation loop). The oscillation circuit 2 is connected to the power supply voltage V
It operates with cc applied to obtain the oscillation frequency f as an output. The frequency adjustment circuit and the like are omitted.
【０００４】温度補償回路３はサーミスタＲP(T)とコン
デンサＣPの並列回路（所謂直接法）からなり、温度に
依存して等価直列容量（並列回路の端子間容量）ＣS(T)
が変化する「第３図（ａ）」。なお、第３図（ｂ）は並
列回路を直列回路に変換した図で、ＲS(T)は等価直列抵
抗である。したがって、水晶振動子１からみた回路容量
（負荷容量）も温度に依存して変化するので、この変化
を適宜に設定することにより水晶振動子１（水晶発振
器）の温度特性を補償する。The temperature compensating circuit 3 comprises a parallel circuit of a thermistor RP (T) and a capacitor CP (so-called direct method), and an equivalent series capacitance (capacitance between terminals of the parallel circuit) CS (T) depending on temperature.
Changes (FIG. 3 (a)). FIG. 3B is a diagram in which a parallel circuit is converted to a serial circuit, and RS (T) is an equivalent series resistance. Therefore, the circuit capacitance (load capacitance) seen from the crystal unit 1 also changes depending on the temperature. By appropriately setting this change, the temperature characteristics of the crystal unit 1 (crystal oscillator) are compensated.
【０００５】可変容量ダイオード４は、周波数制御回路
（未図示）からの周波数制御電圧ＶCが分割抵抗Ｒ1、Ｒ
2の中点から印加され、端子間の容量を変化させる。し
たがって、周波数制御電圧ＶCに依存して負荷容量が変
化するので、発振周波数ｆoを制御できる。第４図は周
波数制御電圧ＶCに対する発振周波数特性図で、周波数
制御電圧ＶCに比例して発振周波数ｆは高くなる。The variable capacitance diode 4 is connected to a frequency control voltage VC from a frequency control circuit (not shown) by dividing resistors R 1, R
Applied from the midpoint of 2, changing the capacitance between the terminals. Therefore, since the load capacitance changes depending on the frequency control voltage VC, the oscillation frequency fo can be controlled. FIG. 4 is an oscillation frequency characteristic diagram with respect to the frequency control voltage VC. The oscillation frequency f increases in proportion to the frequency control voltage VC.
【０００６】通常では、周波数制御電圧ＶCの中心電圧
（中心制御電圧ＶC0とする）は、目的周波数ｆr近傍の
発振周波数（規定周波数とする）ｆoとなる電圧に、予
め設定される。そして、前述のように基地局からの目的
周波数ｆrと発振周波数ｆを比較した差電圧を周波数制
御電圧として入力し、発振周波数ｆを目的周波数ｆrに
常に追従させる。Normally, the center voltage of the frequency control voltage VC (referred to as the center control voltage VC0) is set in advance to a voltage at which the oscillation frequency (specified frequency) near the target frequency fr becomes the oscillation frequency fo. Then, as described above, the difference voltage obtained by comparing the target frequency fr and the oscillation frequency f from the base station is input as a frequency control voltage, and the oscillation frequency f always follows the target frequency fr.
【０００７】このようなことから、この種の電圧制御発
振器では、水晶発振器の周波数温度特性を補償した上
で、発振周波数ｆを制御して基準周波数としての目的周
波数ｆrに一致させることができる。したがって、基準
周波数を常に維持するので、携帯電話等におけるＰＬＬ
回路の基準信号源として最適となる。また、温度補償を
直接法としているので、定電圧源等を要することなく回
路構成を簡易にする。For this reason, in this type of voltage controlled oscillator, after compensating for the frequency temperature characteristics of the crystal oscillator, the oscillation frequency f can be controlled to match the target frequency fr as the reference frequency. Therefore, since the reference frequency is always maintained, the PLL in the mobile phone or the like is used.
It is optimal as a reference signal source for a circuit. Further, since the temperature compensation is a direct method, the circuit configuration is simplified without requiring a constant voltage source or the like.
【０００８】[0008]
【発明が解決しようとする課題】（従来技術の問題点）
しかしながら、上記構成の電圧制御発振器では、周波数
制御電圧ＶCを印加したときと、これを印加しないとき
とでは、発振周波数ｆが異なることに起因して次の問題
があった。[Problems to be Solved by the Invention]
However, the voltage controlled oscillator having the above configuration has the following problem due to the difference in the oscillation frequency f between when the frequency control voltage VC is applied and when it is not applied.
【０００９】すなわち、近年では、通話状態時以外等の
不要時には、例えば周波数制御回路の電源をOFFにし
て、節電効果（低消費電力化）を高めるようにしてい
る。この場合、周波数制御電圧は０Ｖであるために可変
容量ダイオード４の容量は最大となって、負荷容量も最
大となる。That is, in recent years, when unnecessary, such as during a call state, the power of the frequency control circuit is turned off, for example, to enhance the power saving effect (low power consumption). In this case, since the frequency control voltage is 0 V, the capacity of the variable capacitance diode 4 is maximized, and the load capacity is also maximized.
【００１０】したがって、発振周波数ｆは規定周波数ｆ
o（≒目目的周波数ｆr）より低い初期周波数ｆLの状態
にある（前第４図参照）。このことから、周波数制御回
路の電源を0Nとしても、例えばＰＬＬ制御とした場合に
は初期周波数ｆLとの比較から目的周波数ｆrに到達する
ので、ロック（固定）されるには時間の掛かる問題があ
った。Therefore, the oscillation frequency f is equal to the specified frequency f
It is in the state of the initial frequency fL lower than o (the target frequency fr) (see FIG. 4). For this reason, even if the power supply of the frequency control circuit is set to 0N, for example, in the case of the PLL control, since the target frequency fr is reached from the comparison with the initial frequency fL, it takes a long time to be locked (fixed). there were.
【００１１】このようなことから、周波数制御電圧ＶC
の無印加時の発振周波数ｆを中心制御電圧ＶC0時の規定
周波数ｆoにしておく必要があった。例えば、後述する
第１図に示したように、分割抵抗Ｒ1、Ｒ2の中点と電源
電圧Ｖccとの間に分割抵抗Ｒ3を設ける。そして、分割
抵抗Ｒ2、Ｒ3の比によって、分割抵抗Ｒ2、Ｒ3の中点ａ
の電圧（中点電圧Ａとする）と中心制御電圧ＶC0とを等
しくする構成が考えられた。From the above, the frequency control voltage VC
It is necessary to keep the oscillation frequency f when no voltage is applied at the specified frequency fo at the time of the central control voltage VC0. For example, as shown in FIG. 1 described later, a dividing resistor R3 is provided between the midpoint of the dividing resistors R1 and R2 and the power supply voltage Vcc. The midpoint a of the divided resistors R2 and R3 is determined by the ratio of the divided resistors R2 and R3.
(The midpoint voltage A) and the center control voltage VC0 have been considered.
【００１２】しかし、このようなものでは、変動の大き
い電源電圧Ｖccを可変容量ダイオード４に直接的に印加
するので、電源電圧変動による発振周波数ｆの変化を大
きくする（電源電圧変動特性を悪化させる）問題があっ
た。ちなみに、電源電圧Ｖccの変動分ΔＶは例えば±５
％程度であり、これに対して、この種の水晶発振器では
電源電圧変動特性による周波数偏差を±０．３ppm以内
とした、極めて高い安定度が求められる。なお、定電圧
源を回路内に設ければよいが、この場合には回路構成を
複雑として簡素化できず小型化指向に逆行する。However, in such a device, since the power supply voltage Vcc having a large fluctuation is directly applied to the variable capacitance diode 4, the change in the oscillation frequency f due to the power supply voltage fluctuation is increased (the power supply voltage fluctuation characteristic is deteriorated). There was a problem. Incidentally, the variation ΔV of the power supply voltage Vcc is, for example, ± 5.
On the other hand, in this type of crystal oscillator, extremely high stability is required in which the frequency deviation due to the power supply voltage fluctuation characteristic is within ± 0.3 ppm. Note that a constant voltage source may be provided in the circuit. However, in this case, the circuit configuration is complicated and cannot be simplified, and this is against the direction of miniaturization.
【００１３】（発明の目的）本発明は、中心制御電圧の
印加時と無印加時の発振周波数を一定にし、しかも電源
電圧変動特性を良好にした電圧制御発振器を提供するこ
とを目的とする。(Object of the Invention) It is an object of the present invention to provide a voltage controlled oscillator having a constant oscillating frequency when a central control voltage is applied and when no central control voltage is applied, and having improved power supply voltage fluctuation characteristics.
【００１４】[0014]
【課題を解決するための手段】本発明は、発振回路を駆
動する電源電圧Ｖccと分割抵抗Ｒ1、Ｒ2の中点との間に
分割抵抗Ｒ3を接続して、分割抵抗Ｒ3と分割抵抗Ｒ2と
の中点電圧Ａを電源電圧Ｖccによって中心制御電圧ＶC0
に近接させ、分割抵抗Ｒ1と分割抵抗Ｒ2の並列抵抗値Ｒ
1・Ｒ2／（Ｒ1＋Ｒ2）を分割抵抗Ｒ3の値よりも小さく
したことを基本的な解決手段とする。According to the present invention, a dividing resistor R3 is connected between a power supply voltage Vcc for driving an oscillation circuit and the midpoint between the dividing resistors R1 and R2. Of the center control voltage VC0 by the power supply voltage Vcc.
, And the parallel resistance value R of the divided resistance R1 and the divided resistance R2.
The basic solution is to make 1 · R2 / (R1 + R2) smaller than the value of the dividing resistor R3.
【００１５】[0015]
【作用】本発明は、電源電圧Ｖccと分割抵抗Ｒ1、Ｒ2の
中点との間に分割抵抗Ｒ3を接続して、中点電圧Ａを中
心制御電圧ＶC0に近接させたので、周波数制御電圧ＶC
の無印加時においても可変容量ダイオード４には、中心
制御電圧ＶC0に近接した中点電圧Ａが印加される。ま
た、分割抵抗Ｒ1と分割抵抗Ｒ2の並列抵抗値Ｒ1・Ｒ2／
（Ｒ1＋Ｒ2）を分割抵抗Ｒ3の値よりも小さくしたの
で、加法定理によって求められる分割抵抗Ｒ1、Ｒ2、Ｒ
3の中点電圧Ａにおける電源電圧Ｖccの係数を小さくす
る。以下、本発明の一実施例を説明する。According to the present invention, since the dividing resistor R3 is connected between the power supply voltage Vcc and the midpoint between the dividing resistors R1 and R2 and the midpoint voltage A is brought close to the center control voltage VC0, the frequency control voltage VC
Is applied, the midpoint voltage A close to the central control voltage VC0 is applied to the variable capacitance diode 4. In addition, the parallel resistance value R1 · R2 / R
Since (R1 + R2) is smaller than the value of the division resistance R3, the division resistances R1, R2, R obtained by the addition theorem
3. The coefficient of the power supply voltage Vcc at the midpoint voltage A is reduced. Hereinafter, an embodiment of the present invention will be described.
【００１６】[0016]
【実施例】第１図は本発明の一実施例を説明する電圧制
御発振器の図である。なお、前従来例図と同一部分には
同番号を付与してその説明は簡略する。電圧制御発振器
は、前述したように、水晶振動子１を有する発振回路
２、温度補償回路３、及び分割抵抗Ｒ1、Ｒ2の中点から
周波数制御電圧を印加される可変容量ダイオード４とか
らなり、分割抵抗Ｒ1、Ｒ2の中点ａと電源電圧Ｖccとの
間に分割抵抗Ｒ3を設けてなる。FIG. 1 is a diagram of a voltage controlled oscillator for explaining one embodiment of the present invention. The same parts as those in the prior art are denoted by the same reference numerals, and description thereof will be simplified. As described above, the voltage controlled oscillator includes the oscillation circuit 2 having the crystal oscillator 1, the temperature compensation circuit 3, and the variable capacitance diode 4 to which the frequency control voltage is applied from the middle point between the division resistors R1 and R2. A dividing resistor R3 is provided between the midpoint a of the dividing resistors R1 and R2 and the power supply voltage Vcc.
【００１７】そして、分割抵抗Ｒ3は分割抵抗Ｒ2との比
によって、分割抵抗Ｒ2、Ｒ3における電源電圧Ｖccから
の中点電圧が下式（１）に基づき、中心制御電圧ＶC0に
一致するように選択される。 The dividing resistor R3 is selected according to the ratio with the dividing resistor R2 so that the midpoint voltage from the power supply voltage Vcc at the dividing resistors R2 and R3 is equal to the center control voltage VC0 based on the following equation (1). Is done.
【００１８】また、分割抵抗Ｒ1は以下に基づき、設定
される。すなわち、このようなものでの、分割抵抗Ｒ
1、Ｒ2、Ｒ3の中点電圧Ａ（Ｖ）は加法定理によって次
の（２）式で示される。 The dividing resistor R1 is set based on the following. That is, the division resistance R
The midpoint voltage A (V) of 1, R2 and R3 is expressed by the following equation (2) by the addition theorem.
【００１９】ここで、（２）式に注目すると、第１項は
周波数制御電圧VC0に関する項であるので、中点電圧Ａ
における電源電圧変動は第２項が支配的となる。そし
て、第２項から分かるように、分割抵抗R3が大きいほ
ど、また分割抵抗Ｒ1、Ｒ2の並列抵抗R1・R2/(R1+R2)が
小さいほど、電源電圧Ｖccの係数は小さくなる。Here, paying attention to equation (2), since the first term is related to the frequency control voltage VC0, the midpoint voltage A
Is dominated by the second term. As can be seen from the second term, the coefficient of the power supply voltage Vcc decreases as the division resistance R3 increases and the parallel resistance R1 · R2 / (R1 + R2) of the division resistances R1 and R2 decreases.
【００２０】したがって、分割抵抗R3の値を大きく、並
列抵抗値R1・R2/(R1+R2)を小さくすることによって、電
源電圧Ｖccの変動分ΔＶも小さくできる。例えば並列抵
抗R1・R2/(R1+R2)を分割抵抗Ｒ3の１／５とすれば、電源
電圧Ｖccとともに変動分ΔＶを１／６にすることができ
る。また、実際的には、分割抵抗Ｒ2、Ｒ3は（１）式に
よって決定されるので、分割抵抗Ｒ1をＲ2、Ｒ3よりも
小さく設定すればよい。Therefore, by increasing the value of the dividing resistor R3 and decreasing the parallel resistance value R1 · R2 / (R1 + R2), the variation ΔV of the power supply voltage Vcc can be reduced. For example, if the parallel resistance R1 · R2 / (R1 + R2) is set to 1/5 of the division resistance R3, the variation ΔV can be reduced to 1/6 together with the power supply voltage Vcc. Actually, since the division resistances R2 and R3 are determined by the equation (1), the division resistance R1 may be set smaller than R2 and R3.
【００２１】このような構成であれば、電源電圧Ｖccと
分割抵抗Ｒ1、Ｒ2の中点との間に分割抵抗Ｒ3を接続し
て、中点電圧Ａを中心制御電圧ＶC0に一致させる。した
がって、周波数制御電圧ＶCの無印加時においても、可
変容量ダイオード４には電源電圧Ｖccに基づいた中心制
御電圧ＶC0が印加されている。したがって、発振周波数
ｆは予め設定された規定周波数ｆ0を維持する。With such a configuration, the dividing resistor R3 is connected between the power supply voltage Vcc and the midpoint of the dividing resistors R1 and R2 so that the midpoint voltage A matches the central control voltage VC0. Therefore, even when the frequency control voltage VC is not applied, the center control voltage VC0 based on the power supply voltage Vcc is applied to the variable capacitance diode 4. Therefore, the oscillation frequency f maintains the preset prescribed frequency f0.
【００２２】このことから、周波数制御回路の電源をOF
FからONにすると、初期周波数ｆLでの発振ではなく規定
周波数ｆ0からの発振となるので、目的周波数ｆrに早期
に到達する。したがって、携帯電話等の通話品質を良好
に維持する。From this, the power supply of the frequency control circuit is turned off.
When it is turned on from F, it oscillates from the specified frequency f0 instead of oscillating at the initial frequency fL, and thus reaches the target frequency fr early. Therefore, the communication quality of a mobile phone or the like is maintained satisfactorily.
【００２３】また、分割抵抗Ｒ1と分割抵抗Ｒ2の並列抵
抗値Ｒ1・Ｒ2／（Ｒ1＋Ｒ2）を分割抵抗Ｒ3よりも小さ
くする。したがって、加法定理によって求められる分割
抵抗Ｒ1、Ｒ2、Ｒ3の中点電圧Ａにおける電源電圧Ｖcc
の係数を小さくする。このことから、電源電圧変動特性
を良好に維持できる。Further, the parallel resistance value R 1 · R 2 / (R 1 + R 2) of the dividing resistor R 1 and the dividing resistor R 2 is made smaller than the dividing resistor R 3. Therefore, the power supply voltage Vcc at the midpoint voltage A of the divided resistors R1, R2, R3 determined by the addition theorem
Is reduced. From this, the power supply voltage fluctuation characteristics can be favorably maintained.
【００２４】また、この実施例では、サーミスタとコン
デンサからなる簡易な温度補償回路を用い、定電圧回路
等を使用することがないので、回路構成を簡素にして小
型化を維持する。In this embodiment, a simple temperature compensating circuit composed of a thermistor and a capacitor is used, and a constant voltage circuit or the like is not used. Therefore, the circuit configuration is simplified and the size is reduced.
【００２５】また、このような構成のものでは、中点電
圧Ａが維持されているので、分割抵抗Ｒ1と可変容量ダ
イオード４の容量との時定数による立ち上がり遅れもな
く、起動特性をも良好にする。Further, in such a configuration, since the midpoint voltage A is maintained, there is no rise delay due to the time constant between the divisional resistor R1 and the capacitance of the variable capacitance diode 4, and the start-up characteristics are excellent. I do.
【００２６】[0026]
【他の事項】上記実施例では、電圧可変容量素子として
可変容量ダイオードを例示したが、電圧に対して実質的
に容量の変化する半導体素子であれば適用できる。ま
た、実施例では、分割抵抗Ｒ1、Ｒ2、Ｒ3の中点電圧Ａ
を中心制御電圧ＶC0に一致させるとしたが、実際的には
±３０％の程度に近接されてあればよい。[Other Matters] In the above embodiment, a variable capacitance diode is exemplified as the voltage variable capacitance element. However, the present invention can be applied to any semiconductor element whose capacitance changes substantially with respect to voltage. In the embodiment, the midpoint voltage A of the division resistors R1, R2, and R3 is used.
Is set to be equal to the center control voltage VC0, but in practice, it is only necessary to be close to about ± 30%.
【００２７】要するに、本発明では、分割抵抗Ｒ1、Ｒ2
の中点電圧Ａを、電源電圧Ｖccとの間に設けた分割抵抗
Ｒ3によって中心制御電圧ＶC0に近接させ、しかも分割
抵抗Ｒ1を小さくすることによって電源電圧変動特性を
良好にしたことを趣旨とするともので、このような趣旨
に基づくものは適宜自在な変更を含め本発明の技術的範
囲に属する。In short, according to the present invention, the split resistors R1, R2
The midpoint voltage A is brought close to the center control voltage VC0 by the dividing resistor R3 provided between the power supply voltage Vcc and the power supply voltage fluctuation characteristic is improved by reducing the dividing resistor R1. Those based on such a purpose belong to the technical scope of the present invention, including any appropriate changes.
【００２８】[0028]
【発明の効果】本発明は、発振回路を駆動する電源電圧
Ｖccと分割抵抗Ｒ1、Ｒ2の中点との間に分割抵抗Ｒ3を
接続して、分割抵抗Ｒ3と分割抵抗Ｒ2との中点電圧を電
源電圧Ｖccによって中心制御電圧ＶC0に近接させ、分割
抵抗Ｒ1と分割抵抗Ｒ2の並列抵抗値Ｒ1・Ｒ2／（Ｒ1＋
Ｒ2）を分割抵抗Ｒ3よりも小さくしたので、中心制御電
圧の印加時と無印加時の発振周波数を一定にし、しかも
電源電圧変動特性を良好にした電圧制御発振器を提供で
きる。According to the present invention, the dividing resistor R3 is connected between the power supply voltage Vcc for driving the oscillation circuit and the midpoint of the dividing resistors R1 and R2, and the midpoint voltage of the dividing resistor R3 and the dividing resistor R2 is connected. Is brought close to the center control voltage VC0 by the power supply voltage Vcc, and the parallel resistance value R1 / R2 / (R1 +
Since R2) is made smaller than the dividing resistor R3, it is possible to provide a voltage-controlled oscillator having a constant oscillation frequency when the central control voltage is applied and when it is not applied, and having excellent power supply voltage fluctuation characteristics.
【図１】本発明の一実施例を説明する電圧制御発振器の
ブロック回路図である。FIG. 1 is a block circuit diagram of a voltage controlled oscillator illustrating an embodiment of the present invention.
【図２】従来例を説明する電圧制御発振器のブロック回
路図である。FIG. 2 is a block circuit diagram of a voltage controlled oscillator illustrating a conventional example.
【図３】従来例を説明する温度補償回路図である。FIG. 3 is a temperature compensation circuit diagram for explaining a conventional example.
【図４】従来例を説明する周波数制御電圧に対する周波
数特性図である。FIG. 4 is a frequency characteristic diagram with respect to a frequency control voltage for explaining a conventional example.
フロントページの続き Ｆターム(参考） 5J079 AA04 BA02 BA12 BA22 DA13 EA01 EA18 EA20 FA13 FA14 FA21 FB11 KA05 5J106 AA01 BB01 CC01 EE18 GG01 HH03 JJ01 KK03 LL01 Continued on the front page F term (reference) 5J079 AA04 BA02 BA12 BA22 DA13 EA01 EA18 EA20 FA13 FA14 FA21 FB11 KA05 5J106 AA01 BB01 CC01 EE18 GG01 HH03 JJ01 KK03 LL01
Claims (1)
て、前記電圧可変容量素子に周波数制御電圧を分割抵抗
Ｒ1、Ｒ2の中点から印加してなる電圧制御型の水晶発振
器において、前記発振回路を駆動する電源電圧と前記分
割抵抗Ｒ1、Ｒ2の中点との間に分割抵抗Ｒ3を接続し
て、前記分割抵抗Ｒ3と前記分割抵抗Ｒ2との中点の電圧
を前記電源電圧によって前記周波数制御電圧の中心電圧
に近接させ、前記分割抵抗Ｒ1と前記分割抵抗Ｒ2の並列
抵抗値Ｒ1・Ｒ2／（Ｒ1＋Ｒ2）を分割抵抗Ｒ3の値より
も小さくしたことを特徴とする電圧制御型の水晶発振
器。1. A voltage controlled crystal oscillator comprising a voltage variable capacitor connected to a crystal oscillator and a frequency control voltage applied to the voltage variable capacitor from a middle point between divided resistors R1 and R2. A dividing resistor R3 is connected between a power supply voltage for driving an oscillation circuit and a midpoint of the dividing resistors R1 and R2, and a voltage at a midpoint between the dividing resistor R3 and the dividing resistor R2 is changed by the power supply voltage. A voltage control type crystal wherein the parallel resistance value R1 / R2 / (R1 + R2) of the dividing resistor R1 and the dividing resistor R2 is made smaller than the value of the dividing resistor R3 so as to be close to the center voltage of the frequency control voltage. Oscillator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP37669098A JP3466944B2 (en) | 1998-12-25 | 1998-12-25 | Voltage controlled crystal oscillator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP37669098A JP3466944B2 (en) | 1998-12-25 | 1998-12-25 | Voltage controlled crystal oscillator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000196359A true JP2000196359A (en) | 2000-07-14 |
| JP3466944B2 JP3466944B2 (en) | 2003-11-17 |
Family
ID=18507565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP37669098A Expired - Fee Related JP3466944B2 (en) | 1998-12-25 | 1998-12-25 | Voltage controlled crystal oscillator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3466944B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009005182A (en) * | 2007-06-22 | 2009-01-08 | Kenwood Corp | Voltage controlled temperature compensated crystal oscillator, and temperature-oscillation frequency characteristics adjustment method |
| US9306580B2 (en) | 2013-11-07 | 2016-04-05 | Seiko Epson Corporation | Oscillation circuit, oscillator, electronic device, mobile object, and oscillator manufacturing method |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5809851B2 (en) * | 2011-06-06 | 2015-11-11 | 日本電波工業株式会社 | Crystal oscillator with temperature chamber |
-
1998
- 1998-12-25 JP JP37669098A patent/JP3466944B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009005182A (en) * | 2007-06-22 | 2009-01-08 | Kenwood Corp | Voltage controlled temperature compensated crystal oscillator, and temperature-oscillation frequency characteristics adjustment method |
| US9306580B2 (en) | 2013-11-07 | 2016-04-05 | Seiko Epson Corporation | Oscillation circuit, oscillator, electronic device, mobile object, and oscillator manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3466944B2 (en) | 2003-11-17 |
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