JPH03131112A - Noise filter - Google Patents
Noise filterInfo
- Publication number
- JPH03131112A JPH03131112A JP26809889A JP26809889A JPH03131112A JP H03131112 A JPH03131112 A JP H03131112A JP 26809889 A JP26809889 A JP 26809889A JP 26809889 A JP26809889 A JP 26809889A JP H03131112 A JPH03131112 A JP H03131112A
- Authority
- JP
- Japan
- Prior art keywords
- noise filter
- ferrite core
- flat
- hole
- foil
- 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.)
- Pending
Links
- 229910000859 α-Fe Inorganic materials 0.000 claims description 26
- 239000004020 conductor Substances 0.000 claims description 22
- 239000011888 foil Substances 0.000 claims description 17
- 238000009413 insulation Methods 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 2
- 239000003990 capacitor Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000009499 grossing Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Landscapes
- Filters And Equalizers (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
（イ）産業上の利用分野
本発明はノイズフィルタに関し、特にスイッチング電源
に用いるスイッチングノイズを除去スルためのノイズフ
ィルタに関する。DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a noise filter, and more particularly to a noise filter for removing switching noise used in a switching power supply.
（ロ）従来の技術
スイッチング電源は第７図に示すように、商用交流電源
を直接整流平滑回路（１１〉で直流に変換し、発振回路
（１２）からの高周波例えば１００ＫＨｚ〜５００ＫＨ
ｚのパルスでスイッチングトランジスタ（１３）をスイ
ッチングし、スイッチングトランジスタ（１３）のコレ
クタ負荷であるフェライトトランス（１４）の２次側よ
り出力電圧を得るものである。２次側の出力電圧は２次
側の整流電圧の変動を誤差増幅器（１５）で検出し、こ
の出力をホトカブラを介してパルス幅変調回路（１６ン
に印加し、発振器（１２）からの高周波基準パルスをパ
ルス幅変調させて安定化のフィードバック制御系を形成
している。(b) Conventional technology Switching power supplies, as shown in Figure 7, convert commercial AC power directly into DC through a rectifying and smoothing circuit (11), and generate a high frequency, for example 100KHz to 500KH, from an oscillation circuit (12).
The switching transistor (13) is switched by the pulse of z, and an output voltage is obtained from the secondary side of the ferrite transformer (14) which is the collector load of the switching transistor (13). The output voltage on the secondary side is determined by detecting fluctuations in the rectified voltage on the secondary side with an error amplifier (15), and applying this output to a pulse width modulation circuit (16) via a photocoupler, which outputs a high frequency signal from an oscillator (12). A stabilizing feedback control system is formed by pulse width modulating the reference pulse.
かかるスイッチング電源は、従来の低周波トランスを小
型軽量の高周波トランス（１４）に置換でき、電源装置
の小型軽量化に大いに寄与するのである。Such a switching power supply can replace the conventional low frequency transformer with a small and lightweight high frequency transformer (14), greatly contributing to the reduction in size and weight of the power supply device.
しかしながらスイッチング電源にはスイッチングノイズ
を発生させる宿命があり、何らかのノイズ対策は不可欠
となる。この対策として、スイッチング周波数およびそ
の高調波を除去するためにノイズフィルタとなるチョー
クコイルを電源回路に挿入する。However, switching power supplies are destined to generate switching noise, so some kind of noise countermeasure is essential. As a countermeasure to this problem, a choke coil that serves as a noise filter is inserted into the power supply circuit to remove the switching frequency and its harmonics.
一般的ノイズフィルタの回路は、第７図に示すように商
用交流電源（１０）と整流平滑回路（１１）との間に挿
入される。Ｌはコモンモードチョークコイルであり、Ｃ
１はノーマルモードノイズ低減用コンデンサであり、Ｃ
２、Ｃ３はコモンモードおよびノーマルモードノイズ低
減用コンデンサである。A general noise filter circuit is inserted between a commercial AC power supply (10) and a rectifying and smoothing circuit (11) as shown in FIG. L is a common mode choke coil, and C
1 is a capacitor for normal mode noise reduction, and C
2. C3 is a common mode and normal mode noise reduction capacitor.
小型のコモンモードチョークコイルとしては、特開昭６
’２−５３０１３号公報（ＨＯ３Ｈ７１０９）等で示さ
れている。As a small common mode choke coil, JP-A-6
It is shown in '2-53013 (HO3H7109) and the like.
第８図にその構造を示す。外形３０ｍｍの一対のっぽ形
コア（２１）を用い、このつば形コア（２１）内に絶縁
板（２２）を介して、両面にスパイラル状コイル（２３
）が形成され、リード線（２４）が前記スパイラル状コ
イル（２３）の両端に接続された厚さ０．５ｍｍ、比誘
電率１００００の誘電体板（２５）を配置している。こ
の結果、誘電体板（２５）は容量成分を持ち、ノーマル
モード低減用コンデンサの効果を有する。Figure 8 shows its structure. A pair of collar-shaped cores (21) with an outer diameter of 30 mm are used, and spiral coils (23
) is formed, and a dielectric plate (25) having a thickness of 0.5 mm and a relative permittivity of 10,000 is arranged, with lead wires (24) connected to both ends of the spiral coil (23). As a result, the dielectric plate (25) has a capacitance component and has the effect of a normal mode reduction capacitor.
（ハ）発明が解決しようとする問題点
しかしながらかかるコモンモードチョークコイルでは部
品の小型化は達成されているが、つぼ形コイルを用い且
つコイルを上下に配置するためその高さには自ずと限界
があり、表面実装部品としてハイブリッド集積回路のな
かに取り込めるに至っていない問題点を有していた。(c) Problems to be solved by the invention However, although the common mode choke coil has achieved miniaturization of parts, there is a natural limit to its height because it uses a pot-shaped coil and the coils are arranged one above the other. However, there were problems that prevented it from being incorporated into hybrid integrated circuits as a surface-mounted component.
また構成点数も多く、小型薄型化の要求には十分とは言
えず、スイッチング電源の小型化の障害となっている問
題点も有していた。In addition, the number of components is large, and it cannot be said to be sufficient to meet the demands for miniaturization and thinning, and has the problem of hindering the miniaturization of switching power supplies.
（ニ）問題点を解決するための手段
本発明はかかる問題点に鑑みてなされ、扁平フェライト
コアに貫通孔を設け、この貫通孔に絶縁被覆した複数本
の箔状導体を密着し挿入して小型扁平のノイズフィルタ
を実現したものである。(d) Means for Solving the Problems The present invention was made in view of the above problems, and consists of providing a through hole in a flat ferrite core, and inserting a plurality of insulating coated foil conductors into the through hole in close contact with each other. This realizes a small and flat noise filter.
（ホ）作用
本発明によれば、扁平フェライトコアに貫通孔を設け、
この貫通孔に絶縁被覆した複数本の箔状導体を密着して
挿入しているので、極めて小型のコモンモードチョーク
トランスを実現できる。(E) Function According to the present invention, a through hole is provided in the flat ferrite core,
Since a plurality of insulating-coated foil conductors are closely inserted into this through hole, an extremely small common mode choke transformer can be realized.
また導体の薄い絶縁被覆層を用いるので、箔状導体とコ
アとの間の容量成分をコモンモード低減用コンデンサと
して用いることができる。Furthermore, since a thin insulating coating layer of the conductor is used, the capacitance component between the foil-like conductor and the core can be used as a common mode reduction capacitor.
さらに扁平フェライトコアと絶縁被覆した箔状導体の、
２つの構成要素でノイズフィルタを実現しているので、
極めて小型薄型の構造となる。Furthermore, the flat ferrite core and the foil conductor with insulation coating,
Since the noise filter is realized with two components,
It has an extremely small and thin structure.
（へ）実施例
第１図及至第６図を参照して本発明のノイズフィルタを
説明する。(F) Embodiment The noise filter of the present invention will be explained with reference to FIGS. 1 to 6.
第１図は本発明によるノイズフィルタの上面図であり、
第２図は扁平フェライトコアの側面図であり、第３図Ａ
、Ｂは絶縁被覆した箔状導体の上面図およびその断面図
である。FIG. 1 is a top view of a noise filter according to the present invention,
Figure 2 is a side view of the flat ferrite core, and Figure 3A is a side view of the flat ferrite core.
, B are a top view and a cross-sectional view of an insulating coated foil conductor.
本発明のノイズフィルタは、扁平フェライトコア（１）
と、絶縁被覆した複数本の箔状導体（２）とで構成され
ている。The noise filter of the present invention has a flat ferrite core (1)
and a plurality of foil-like conductors (2) coated with insulation.
扁平フェライトコア（１）は、同一特性を有する均一の
フェライト材料（例えば、日本フェライト社のＧＰ−７
）を焼成して形成される。形状は扁平で直方体であり、
貫通孔（３）は薄い側面に直交するように延在されてい
る０貫通孔（３）は１以上形成されるが、電源ラインに
挿入される用途から２個離間して設けられるのが通常で
ある。The flat ferrite core (1) is made of a uniform ferrite material having the same characteristics (for example, GP-7 manufactured by Nippon Ferrite Co., Ltd.).
) is formed by firing. The shape is flat and rectangular,
The through-hole (3) extends perpendicularly to the thin side surface.One or more through-holes (3) are formed, but usually two are provided at a distance from each other due to the purpose of inserting it into a power supply line. It is.
従って図面では貫通孔（３）を２個有する扁平フェライ
トコア（１）が示されている。この図面を参照すると、
フェライトコア（１）は４６ｍｍＸ３０ｍｍＸ８ｍｍの
扁平直方体形状であり、貫通孔（３）は４６ｍｍｘ８ｍ
ｍの側面から対向面まで直線状に延在され、８ｍｍの厚
みの中央に位置している０貫通孔（３〉の断面は１３ｍ
ｍＸ０．６ｍｍであり、両賞通孔（３）（３）間は８ｍ
ｍはど離している。この貫通孔（３）は４ｍｍの厚みの
フェライト板に０．３ｍｍの深さの溝を形成したのち、
２枚のフェライト板を貼り合わせて形成される。なお他
の方法としては、金型を用いる方法も可能である。Therefore, the drawing shows a flat ferrite core (1) having two through holes (3). Referring to this drawing,
The ferrite core (1) has a flat rectangular parallelepiped shape of 46 mm x 30 mm x 8 mm, and the through hole (3) is 46 mm x 8 m.
The cross section of 0 through hole (3> is 13 m), which extends linearly from the side surface of
m x 0.6 mm, and the distance between both prize holes (3) (3) is 8 m.
How far is m? This through hole (3) is made by forming a groove with a depth of 0.3 mm in a 4 mm thick ferrite plate.
It is formed by bonding two ferrite plates together. Note that as another method, a method using a mold is also possible.
複数本の箔状導体（２）は、錫メツキ軟銅平角線（４）
を複数本平行に延在させ、ポリエステル（５）でサンド
インチして接着して形成されている。錫メツキ軟銅平角
線（４）は１つの箔状導体（２）当り４本とし、厚み０
．１ｍｍで幅１．２７ｍｍのものを用い、線間ピッチは
２．５４ｍｍに配置しｔコ。従って箔状導体（２）の仕
上がり厚はポリエステルく５）を加えて、０．４３ｍｍ
になっている。The plurality of foil conductors (2) are tin-plated annealed copper rectangular wires (4)
It is formed by extending a plurality of pieces in parallel, sandwiching them with polyester (5) and adhering them. There are four tin-plated annealed copper flat wires (4) per foil conductor (2), and the thickness is 0.
．． A wire with a diameter of 1 mm and a width of 1.27 mm was used, and the pitch between the lines was 2.54 mm. Therefore, the finished thickness of the foil conductor (2) is 0.43 mm, including the polyester layer 5).
It has become.
この箔状導体（２）は貫通孔（３）に１枚ずつ挿入され
、箔状導体（２）の両端はフェライトコア（１）より突
出している。さらに箔状導体（２）端部の錫メツキ軟鋼
平角線く４）は露出されており、ノイズフィルタと他の
回路との接続に用いられる。The foil conductors (2) are inserted one by one into the through holes (3), and both ends of the foil conductors (2) protrude from the ferrite core (1). Furthermore, the tin-plated mild steel rectangular wire 4) at the end of the foil conductor (2) is exposed and is used to connect the noise filter to other circuits.
次に本発明のノイズフィルタの等価回路図を第４図に示
す。このノイズフィルタは箔状導体（２）とフェライト
コア（１）間で形成されるＬ成分とポリエステル（５）
を誘電体層として箔状導体（２）とフェライトコア（１
）間で形成されるＣ成分とを有する。しかもこのＣ成分
はＬ成分とフェライトグランド（ＦＧ）間に挿入される
ため、コモンモードノイズ低減用コンデンサとしての働
きを有する。本実施例ではこのＬ成分は約２μＨ，Ｃ成
分は５〜２５ＰＦを得ている。Next, an equivalent circuit diagram of the noise filter of the present invention is shown in FIG. This noise filter consists of an L component formed between a foil conductor (2) and a ferrite core (1), and a polyester (5).
A foil conductor (2) and a ferrite core (1) are used as dielectric layers.
) and a C component formed between. Furthermore, since this C component is inserted between the L component and the ferrite ground (FG), it functions as a common mode noise reduction capacitor. In this embodiment, the L component is approximately 2 μH, and the C component is 5 to 25 PF.
さらに第５図および第６図に本発明によるノイズフィル
タの特性を示す。第５図は第１図に具体的に説明したノ
イズフィルタのインダクタンスの周波数特性を示し、イ
ンダクタンスは約３ＭＨ２まで平坦に約２μＨであり、
１０ＭＨ２でも約０．７μＨを有している。一方、第６
図は同様にインピーダンスの周波数特性であり、約３Ｍ
Ｈ２より急峻に立ち上がっている。この結果、本発明の
ノイズフィルタは５０Ｈ２〜約２〜ＭＨ２の広帯域に渡
ってフィルタ効果を有し、スイッチング周波数５００Ｋ
Ｈ２のスイッチング電源においても５００ＫＨ２とその
高調波のスイッチングノイズを確実に除去できる。Further, FIGS. 5 and 6 show the characteristics of the noise filter according to the present invention. FIG. 5 shows the frequency characteristics of the inductance of the noise filter specifically explained in FIG. 1, and the inductance is approximately 2 μH flat up to approximately 3 MH2.
Even 10MH2 has about 0.7 μH. On the other hand, the 6th
The figure also shows the frequency characteristics of impedance, about 3M
It rises more steeply than H2. As a result, the noise filter of the present invention has a filter effect over a wide band of 50H2 to about 2 to MH2, and has a switching frequency of 500K.
Even in H2 switching power supplies, switching noise of 500KH2 and its harmonics can be reliably removed.
（ト）発明の効果
本発明によれば、扁平フェライトコア（１）を用い且つ
貫通孔（３）に箔状導体（２）を挿入するだけで、ノイ
ズフィルタを実現できるので、はぼ扁平フェライトコア
の大きさでノイズフィルタを完成でき、小型薄型化を図
れて表面実装可能なノイズフィルタを提供できる。(G) Effects of the Invention According to the present invention, a noise filter can be realized by simply using a flat ferrite core (1) and inserting a foil conductor (2) into a through hole (3). A noise filter can be completed depending on the size of the core, and a noise filter that can be made smaller and thinner and can be surface mounted can be provided.
また絶縁被覆した箔状導体（２）を貫通孔（３）に挿入
するのみでノイズフィルタを完成でき、極めて少ない構
成部品で形成され、ノイズフィルタの組立工程を省略で
きる。Further, the noise filter can be completed by simply inserting the insulating coated foil conductor (2) into the through hole (3), and is formed using extremely few components, so that the noise filter assembly process can be omitted.
さらに絶縁被覆した箔状導体（２）によりコモンモード
ノイズ低減用コンデンサをノイズフィルタ内に取り込む
ことができ、外付けのコモンモード低減用コンデンサを
無くするか小さくできる。Furthermore, the insulating coated foil conductor (2) allows the common mode noise reduction capacitor to be incorporated into the noise filter, making it possible to eliminate or reduce the size of the external common mode noise reduction capacitor.
第１図は本発明によるノイズフィルタを説明する上面図
、第２図は本発明に用いる扁平フェライトコアの側面図
、第３図は本発明に用いる導体の上面図および断面図、
第４図は本発明のノイズフィルタの等価回路図、第５図
および第６図は本発明のノイズフィルタの特性図、第７
図は一般的なスイッチング電源を説明する回路図、第８
図は従来のノイズフィルタを説明するための分解斜視図
である。
（１）は扁平フェライトコア、（２）は箔状導体、（３
）は貫通孔、（４）は錫メツキ軟鋼平角線、（５）はポ
リエステルフィルムである。FIG. 1 is a top view illustrating a noise filter according to the present invention, FIG. 2 is a side view of a flat ferrite core used in the present invention, and FIG. 3 is a top view and a sectional view of a conductor used in the present invention.
FIG. 4 is an equivalent circuit diagram of the noise filter of the present invention, FIGS. 5 and 6 are characteristic diagrams of the noise filter of the present invention, and FIG.
The figure is a circuit diagram explaining a general switching power supply.
The figure is an exploded perspective view for explaining a conventional noise filter. (1) is a flat ferrite core, (2) is a foil conductor, (3
) is a through hole, (4) is a tin-plated mild steel rectangular wire, and (5) is a polyester film.
Claims (4)
を設け、前記貫通孔に絶縁被覆され且つ互いに離間され
た複数本の箔状導体を密着して挿入したことを特徴とす
るノイズフィルタ。(1) A noise filter characterized in that a flat ferrite core is provided with at least one through hole, and a plurality of foil conductors coated with insulation and spaced apart from each other are closely inserted into the through hole.
交する方向に設けたことを特徴とする請求項１記載のノ
イズフィルタ。(2) The noise filter according to claim 1, wherein the through hole is provided in a direction perpendicular to a side surface of the flat ferrite core.
で形成されることを特徴とする請求項１記載のノイズフ
ィルタ。(3) The noise filter according to claim 1, wherein the ferrite core is formed of a ferrite material having the same characteristics.
通孔にそれぞれ絶縁被覆され且つ互いに離間された複数
本の箔状導体を密着して挿入したことを特徴とするノイ
ズフィルタ。(4) A noise filter characterized in that two through holes are provided in a flat ferrite core, and a plurality of foil-like conductors, each of which is insulated and spaced apart, are closely inserted into the through holes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26809889A JPH03131112A (en) | 1989-10-17 | 1989-10-17 | Noise filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26809889A JPH03131112A (en) | 1989-10-17 | 1989-10-17 | Noise filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03131112A true JPH03131112A (en) | 1991-06-04 |
Family
ID=17453866
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26809889A Pending JPH03131112A (en) | 1989-10-17 | 1989-10-17 | Noise filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03131112A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5220298A (en) * | 1990-07-24 | 1993-06-15 | Kabushiki Kaisha Toshiba | Integrated circuit having a built-in noise filter |
| US5801597A (en) * | 1997-02-05 | 1998-09-01 | Lucent Technologies Inc. | Printed-circuit board-mountable ferrite EMI filter |
-
1989
- 1989-10-17 JP JP26809889A patent/JPH03131112A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5220298A (en) * | 1990-07-24 | 1993-06-15 | Kabushiki Kaisha Toshiba | Integrated circuit having a built-in noise filter |
| US5801597A (en) * | 1997-02-05 | 1998-09-01 | Lucent Technologies Inc. | Printed-circuit board-mountable ferrite EMI filter |
| US5914644A (en) * | 1997-02-05 | 1999-06-22 | Lucent Technologies Inc. | Printed-circuit board-mountable ferrite EMI filter |
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