JP3096482B2 - Crystal oscillator - Google Patents
Crystal oscillatorInfo
- Publication number
- JP3096482B2 JP3096482B2 JP03058000A JP5800091A JP3096482B2 JP 3096482 B2 JP3096482 B2 JP 3096482B2 JP 03058000 A JP03058000 A JP 03058000A JP 5800091 A JP5800091 A JP 5800091A JP 3096482 B2 JP3096482 B2 JP 3096482B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- temperature
- frequency
- frequency adjustment
- circuit board
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0213—Electrical arrangements not otherwise provided for
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/18—Printed circuits structurally associated with non-printed electric components
Landscapes
- Oscillators With Electromechanical Resonators (AREA)
Description
【００１】[0101]
【産業上の利用分野】本発明は水晶発振器を利用分野と
し、特に負荷変動による発振周波数の変化を防止した小
型な温度補償発振器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal oscillator, and more particularly to a small-sized temperature-compensated oscillator which prevents a change in oscillation frequency due to a load change.
【０００２】[0002]
【発明の背景】温度補償発振器は、水晶振動子に起因し
た周波数温度特性を補償して高安定とするものとして、
特に動的環境のもとでの需要が多くなっている。近年で
は、世情の趨勢等により、これらのものにおいても一層
の小型化が望まれている。例えばその一つとして各回路
素子を回路基板の両面に配置する試みがある。BACKGROUND OF THE INVENTION A temperature-compensated oscillator compensates for frequency-temperature characteristics caused by a crystal oscillator and achieves high stability.
In particular, demand in dynamic environments is increasing. In recent years, further downsizing has been desired for these products due to the trend of the world and the like. For example, as one of them, there is an attempt to arrange each circuit element on both sides of a circuit board.
【０００３】[0003]
【従来技術】第２図は従来例を説明する温度補償発振器
の回路図である。温度補償発振器は、基本的に、発振子
としての水晶振動子１と、発振回路２と、温度補償回路
３とからなる。水晶振動子１は例えばＡＴカットとし、
周波数温度特性を３次曲線とする。発振回路２は、発振
用トランジスタ４及び発振用コンデンサ５（ａｂ）から
からなるコルピッツ型とする。通常では、発振回路２に
例えばカスケード接続した出力回路６となる緩衝増幅器
７を設けてなる。温度補償回路３は水晶振動子１に接続
し、水晶振動子１に起因した周波数温度特性を補償す
る。例えば直接補償型とする高温側８用及び低温側９用
のサーミスタ１０（ａｂ）、抵抗１１（ａｂ）、コンデ
ンサ１２（ａｂ）からなる。そして、温度補償回路３に
発振周波数の調整用コンデンサ１３を接続して構成され
る。なお、温度補償回路３と調整用コンデンサ１３を併
せて周波数調整回路１４とする。また、図中の符号１４
はバイアス用の抵抗、１５はパスコンデンサである。2. Description of the Related Art FIG. 2 is a circuit diagram of a temperature compensated oscillator for explaining a conventional example. The temperature-compensated oscillator basically includes a crystal resonator 1 as an oscillator, an oscillation circuit 2, and a temperature compensation circuit 3. The crystal unit 1 is, for example, an AT cut,
The frequency temperature characteristic is a cubic curve. The oscillation circuit 2 is a Colpitts type including an oscillation transistor 4 and an oscillation capacitor 5 (ab). Normally, the oscillation circuit 2 is provided with, for example, a buffer amplifier 7 serving as an output circuit 6 connected in cascade. The temperature compensating circuit 3 is connected to the crystal unit 1 and compensates for frequency-temperature characteristics caused by the crystal unit 1. For example, a direct compensation type thermistor 10 (ab) for the high temperature side 8 and the low temperature side 9, a resistor 11 (ab), and a capacitor 12 (ab). The temperature compensating circuit 3 is connected to an oscillation frequency adjusting capacitor 13. The temperature compensating circuit 3 and the adjusting capacitor 13 are collectively referred to as a frequency adjusting circuit 14. Also, reference numeral 14 in FIG.
Is a bias resistor, and 15 is a pass capacitor.
【０００４】[0004]
【従来技術の問題点】しかしながら、上記構成の温度補
償発振器では、一般に、第３図のブロック図に示したよ
うに、出力端ｐと周波数調整回路１４との間には浮遊容
量Ｃ0が存在する。そして、この浮遊容量Ｃ0は、周波数
調整用回路１４と出力端ｐに接続する負荷１６とを電気
的に結合させる。ここでの負荷とは温度補償発振器の接
続される電子機器の回路（未図示）である。したがっ
て、負荷１６のインピーダンスが変化する所謂負荷変動
があると、周波数調整回路１４は直接的に影響を受け、
これに伴い発振周波数が変化する。なお、浮遊容量は発
振回路２及び出力回路２との間にも発生するが、これを
経由しての負荷変動による影響は小さく、無視できる。
また、浮遊容量Ｃ0がなくとも、負荷１６は出力回路６
を経て周波数調整回路１４に接続するので、その影響が
危倶される。しかし、負荷変動分は出力回路により遮断
されるので、周波数調整回路１４への影響は小さい。こ
のようなことから、通常では、出力回路６と周波数調整
回路１４との間を大きくする配置によって、浮遊容量に
よる負荷側との電気的結合を防止するようにしている。
しかし、小型化を計るに際して、回路基板（未図示）を
小さくすると、出力回路６と周波数調整回路１４との間
は必然的に小さくなり、両者間の浮遊容量による電気的
結合を防止するには限界があった。そして、これによ
り、負荷変動による発振周波数の変化を抑止することを
困難としていた。特に、第４図に示したように回路素子
を表面実装用素子１７（ａｂ）とし、回路基板１８の一
主面に出力回路６を、他主面に周波数調整回路１４を高
密度に配置した場合は、両者間の電気的結合を密にし、
負荷変動による周波数変化への影響は多大なものとな
る。すなわち、表面実装用素子１７（ａｂ）の電極１９
あるいはこれが接続する電極パターン（未図示）は回路
基板１８を挟んで対向する配置となり、さらに回路基板
１８はセラミックでその厚みは０．５ｍｍ程度で高誘電
体層となり、完全にコンデンサを形成してしまうからで
ある。BACKGROUND Problems of the Related Art However, in the temperature compensation oscillator of the above configuration, generally as shown in the block diagram of Figure 3, there is a stray capacitance C 0 between the output terminal p and the frequency adjustment circuit 14 I do. The stray capacitance C 0 electrically couples the frequency adjusting circuit 14 and the load 16 connected to the output terminal p. The load here is a circuit (not shown) of the electronic device to which the temperature compensated oscillator is connected. Therefore, when there is a so-called load change in which the impedance of the load 16 changes, the frequency adjustment circuit 14 is directly affected,
The oscillation frequency changes accordingly. Although the stray capacitance is also generated between the oscillation circuit 2 and the output circuit 2, the influence of the load fluctuation via the stray capacitance is small and can be ignored.
Further, even if there is no stray capacitance C 0 , the load 16 is connected to the output circuit 6.
Is connected to the frequency adjustment circuit 14 via the control circuit, the influence of which is jeopardized. However, since the load fluctuation is cut off by the output circuit, the influence on the frequency adjustment circuit 14 is small. For this reason, usually, the arrangement between the output circuit 6 and the frequency adjustment circuit 14 is increased to prevent electrical coupling with the load side due to stray capacitance.
However, when the size of the circuit board (not shown) is reduced in order to reduce the size, the distance between the output circuit 6 and the frequency adjustment circuit 14 is inevitably reduced. There was a limit. This makes it difficult to suppress a change in the oscillation frequency due to a load change. In particular, as shown in FIG. 4, the circuit element is a surface mounting element 17 (ab), and the output circuit 6 is arranged on one main surface of the circuit board 18 and the frequency adjustment circuit 14 is arranged on the other main surface at high density. In such cases, make the electrical coupling between
The effect of the load change on the frequency change is enormous. That is, the electrode 19 of the surface mounting element 17 (ab)
Alternatively, an electrode pattern (not shown) to which this is connected faces the circuit board 18 with the circuit board 18 interposed therebetween. Further, the circuit board 18 is made of ceramic and has a thickness of about 0.5 mm and becomes a high dielectric layer. It is because.
【０００５】[0005]
【発明の目的】本発明は、負荷変動による発振周波数の
変化を防止して、小型化を促進する水晶発振器を提供す
ることを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a crystal oscillator which prevents a change in oscillation frequency due to a load change and promotes miniaturization.
【０００６】[0006]
【解決手段】本発明は、回路基板の一面に出力回路を、
他面に周波数調整回路を配置し、かつ前記回路基板にシ
ールド層を設けて該出力回路と温度補償回路との容量結
合を減じたことを解決手段とする。以下、本発明の一実
施例を説明する。The present invention provides an output circuit on one surface of a circuit board,
A solution is to dispose a frequency adjustment circuit on the other surface and provide a shield layer on the circuit board to reduce capacitive coupling between the output circuit and the temperature compensation circuit. Hereinafter, an embodiment of the present invention will be described.
【０００７】[0007]
【実施例】第１図は本発明の一実施例を説明する温度補
償発振器の断面図である。なお、前従来例図と同一部分
の説明は省略する。温度補償発振器は、前述同様の、水
晶振動子１と、出力回路６を付加した発振回路２と、周
波数調整回路１４（温度補償回路３と調整用コンデンサ
１３）とからなる（前第２図及び第３図参照）。そし
て、これらを形成する主に表面実装用とした各素子（未
図示）を回路基板２０の両面に配設する。この実施例で
は、回路基板２０の一主面に発振回路２と出力回路６
を、他主面に周波数調整回路１４を設ける。そして、回
路基板２０をシールド層２１の介在した多層基板として
構成する。なお、回路基板２０の一端側両端部には出力
端ｐとしてのリード端子２２、電源用のリード端子（未
図示）とを設ける。そして、水晶振動子１をリード端子
２２と反対側となる他端部の側面に装着する。また、基
準電位用の端子として金属カバー２３の爪部２４を兼用
する。このような構成であれば、シールド層２１によ
り、出力回路６と周波数調整回路１４とを電気的に遮断
し、両者間（表面実装用素子の電極間及び基板両面のパ
ターン間）の浮遊容量による結合を防止する。したがっ
て、負荷変動があったとしても、 周波数調整回路１４
への影響を小さくし、これによる発振周波数の変化を抑
止できる。また、回路基板２０の両面に各素子を分割し
て配置するので、小型化をも促進できる。なお、リード
端子２２と調整用回路１４との間にも浮遊容量は発生す
るが、その対向面積及び両者間に介在する空気のの誘電
率は小さく、さらに両者間の距離は大きいため、その容
量値は無視される。FIG. 1 is a sectional view of a temperature compensated oscillator for explaining an embodiment of the present invention. The description of the same parts as in the prior art example is omitted. The temperature-compensated oscillator includes the crystal oscillator 1, the oscillation circuit 2 to which the output circuit 6 is added, and the frequency adjustment circuit 14 (the temperature compensation circuit 3 and the adjustment capacitor 13) as described above (see FIG. 2 and FIG. (See FIG. 3). Then, elements (not shown) mainly for surface mounting, which form these components, are arranged on both surfaces of the circuit board 20. In this embodiment, the oscillation circuit 2 and the output circuit 6 are provided on one main surface of the circuit board 20.
And a frequency adjustment circuit 14 is provided on the other main surface. Then, the circuit board 20 is configured as a multilayer board with the shield layer 21 interposed. A lead terminal 22 as an output terminal p and a power supply lead terminal (not shown) are provided at both ends on one end side of the circuit board 20. Then, the crystal unit 1 is mounted on the side surface of the other end opposite to the lead terminal 22. The claw portion 24 of the metal cover 23 is also used as a terminal for the reference potential. With such a configuration, the output circuit 6 and the frequency adjustment circuit 14 are electrically cut off by the shield layer 21, and the stray capacitance between them (between the electrodes of the surface mounting element and between the patterns on both surfaces of the substrate). Prevent coupling. Therefore, even if there is a load change, the frequency adjustment circuit 14
Influence on the oscillation frequency, and the change in the oscillation frequency due to this can be suppressed. In addition, since each element is divided and arranged on both surfaces of the circuit board 20, miniaturization can be promoted. Although a stray capacitance is also generated between the lead terminal 22 and the adjustment circuit 14, the opposing area and the dielectric constant of air interposed therebetween are small, and the distance between the two is large. The value is ignored.
【０００８】[0008]
【他の事項】なお、上記実施例では、周波数調整回路１
４は温度補償回路３と調整用コンデンサ１３（可変形で
ある必要はない）としたが、これら以外にも発振周波数
に特に影響を与えるものであれば、この周波数調整回路
１４に含まれるものである。また、周波数調整回路１４
の全てを他主面側に配置したが、その中でも特に影響の
強い一部の素子例えばコンデンサのみを配置してもよ
い。また、温度補償回路３は直接補償型としたが、可変
容量ダイオードを用いた間接補償型のものでも適用され
るもので、その他種々の変更を可能とするものである。[Other Matters] In the above embodiment, the frequency adjustment circuit 1
Reference numeral 4 denotes the temperature compensating circuit 3 and the adjusting capacitor 13 (they need not be variable). However, any other elements which particularly affect the oscillation frequency are included in the frequency adjusting circuit 14. is there. The frequency adjustment circuit 14
Are arranged on the other principal surface side, but among them, only a part of the elements particularly influential, for example, only a capacitor may be arranged. Further, the temperature compensation circuit 3 is of the direct compensation type, but may be applied to an indirect compensation type using a variable capacitance diode, and various other changes are possible.
【発明の効果】本発明は、回路基板の一面に出力回路
を、他面に周波数調整回路を配置し、かつ前記回路基板
にシールド層を設けて該出力回路と温度補償回路との容
量結合を減じたので、負荷変動による発振周波数の変化
を防止して、小型化を促進する水晶発振器を提供でき
る。According to the present invention, an output circuit is arranged on one side of a circuit board, a frequency adjustment circuit is arranged on the other side, and a shield layer is provided on the circuit board to provide capacitive coupling between the output circuit and the temperature compensation circuit. Since it has been reduced, it is possible to provide a crystal oscillator that prevents a change in oscillation frequency due to a load change and promotes miniaturization.
【０００９】[0009]
【図１】本発明による温度補償発振器の主要部断面図で
ある。FIG. 1 is a sectional view of a main part of a temperature compensated oscillator according to the present invention.
【図２】従来例を説明する温度補償発振器の回路図であ
る。FIG. 2 is a circuit diagram of a temperature compensated oscillator explaining a conventional example.
【図３】従来例の問題点を説明する温度補償発振器のブ
ロック図である。FIG. 3 is a block diagram of a temperature-compensated oscillator explaining a problem of a conventional example.
【図４】従来例の問題点を説明する回路基板の一部断面
図である。FIG. 4 is a partial cross-sectional view of a circuit board explaining a problem of a conventional example.
１ 水晶振動子、２ 発振回路、３ 温度補償回路、１
３調整用コンデンサ１４ 周波数調整回路、２０ 回路
基板、２１ シールド層、２２ リード端子２３ 金属
カバー、２４ 爪部1 crystal oscillator, 2 oscillation circuit, 3 temperature compensation circuit, 1
3 adjustment capacitor 14 frequency adjustment circuit, 20 circuit board, 21 shield layer, 22 lead terminal 23 metal cover, 24 claw
Claims (2)
を回路基板に配置して構成した温度補償発振器におい
て、前記回路基板の一面に出力回路を、他面に周波数調
整回路を配置し、かつ前記回路基板にシールド層を設け
て該出力回路と温度補償回路との容量結合を減じたこと
を特徴とする水晶発振器。1. A temperature compensated oscillator comprising an oscillation circuit, an output circuit, and a frequency adjustment circuit arranged on a circuit board, wherein an output circuit is arranged on one side of the circuit board, and a frequency adjustment circuit is arranged on the other side. A crystal oscillator, wherein a shield layer is provided on the circuit board to reduce capacitive coupling between the output circuit and the temperature compensation circuit.
は調整用コンデンサである請求項１の水晶発振器。2. The crystal oscillator according to claim 1, wherein said frequency adjustment circuit is a temperature compensation circuit or an adjustment capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03058000A JP3096482B2 (en) | 1991-02-28 | 1991-02-28 | Crystal oscillator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03058000A JP3096482B2 (en) | 1991-02-28 | 1991-02-28 | Crystal oscillator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05121937A JPH05121937A (en) | 1993-05-18 |
| JP3096482B2 true JP3096482B2 (en) | 2000-10-10 |
Family
ID=13071728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03058000A Expired - Fee Related JP3096482B2 (en) | 1991-02-28 | 1991-02-28 | Crystal oscillator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3096482B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100703212B1 (en) * | 2005-12-14 | 2007-04-06 | 삼성전기주식회사 | A shielding structure of crystal oscillator |
| JP4983240B2 (en) * | 2006-12-13 | 2012-07-25 | 株式会社大真空 | Piezoelectric vibration oscillator |
-
1991
- 1991-02-28 JP JP03058000A patent/JP3096482B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05121937A (en) | 1993-05-18 |
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