JPH02149120A - Low-pass filter - Google Patents
Low-pass filterInfo
- Publication number
- JPH02149120A JPH02149120A JP30334188A JP30334188A JPH02149120A JP H02149120 A JPH02149120 A JP H02149120A JP 30334188 A JP30334188 A JP 30334188A JP 30334188 A JP30334188 A JP 30334188A JP H02149120 A JPH02149120 A JP H02149120A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- fdnr
- filter
- fdnr circuit
- frequency characteristics
- 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.)
- Granted
Links
- 238000009966 trimming Methods 0.000 claims abstract description 11
- 238000002955 isolation Methods 0.000 claims description 2
- 238000000926 separation method Methods 0.000 abstract 2
- 230000005540 biological transmission Effects 0.000 description 13
- 239000003990 capacitor Substances 0.000 description 5
- 238000000034 method Methods 0.000 description 3
- 239000000470 constituent Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
Landscapes
- Networks Using Active Elements (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分Ｗ＞
本発明はＦＤＮＲ回路を用いたローパスフィルタ装置に
関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application W> The present invention relates to a low-pass filter device using an FDNR circuit.
（従来の技術）
ｎ次のローパスフィルタ回路は主としてコンデンサ及び
コイル（リアクトル）の梯子回路で形成されるが、基板
に回路を実装する場合、コンデンサやコイルは抵抗のよ
うに基板に印刷形成できず電子部品として基板にハンダ
付けして実装しなければならなく、その製造が煩雑とな
る。そこでフィルタ回路を形成する各インピーダンスを
複素変数（ｊω）で除算した構成素子に変換する所謂Ｌ
Ｃシュミレーシ１ン法で、コイルを使用しない等両回路
を形成している。この等両回路において容量分のインピ
ーダンス（コンデンサ）はＦＤＮＲ回路に置換えされる
もので、ＦＤＮＲ回路を用いた連立チェピシェフ形フィ
ルタは実開昭５６−１０４２３２号公報、同６１−１０
７２２４号公報等に開示されている。(Prior art) An n-th order low-pass filter circuit is mainly formed of a ladder circuit of capacitors and coils (reactors), but when mounting the circuit on a board, capacitors and coils cannot be printed on the board like resistors. As an electronic component, it must be soldered and mounted on a board, making its manufacture complicated. Therefore, the so-called L converts each impedance forming the filter circuit into a component divided by a complex variable (jω).
Both circuits are formed using the C simulation method without using coils. In both circuits, the impedance (capacitor) corresponding to the capacitance is replaced with an FDNR circuit, and the simultaneous Chepyshev type filter using the FDNR circuit is disclosed in Utility Model Application No. 56-104232 and No. 61-10.
This method is disclosed in Japanese Patent No. 7224 and the like.
前述の連立チェピシェフ形ローパスフィルタ回路は、第
１図に例示するように梯子状の多段とした各フィルタ部
（並列態様に接続されるＦＤＮＲ回路Ｚ１とこれとの直
列抵抗Ｒ１と、直列態様に接続される抵抗Ｒ１よりなる
１型フイルタ）の周波数特性が重合した特性を持つも゛
ので、減衰が鋭く減衰域での減衰が多くとれ、更にフィ
ルタ部の数と対応する伝達零点を有すると云う特徴を備
えている。As illustrated in FIG. 1, the above-mentioned simultaneous Chepyshev type low-pass filter circuit has a ladder-like multi-stage filter section (FDNR circuit Z1 connected in parallel and series resistor R1 connected thereto, connected in series). Since the frequency characteristics of the Type 1 filter (which is made up of the resistor R1) are superimposed, the attenuation is sharp and there is a large amount of attenuation in the attenuation range, and it also has a transmission zero point corresponding to the number of filter sections. It is equipped with
（発明が解決しようとする課題）
ｉｔＪ 記Ｆ Ｄ Ｎ Ｒ回路タイプのローパスフィル
タ回路は現実に回路基板に実装した場合、設計上の理論
特性が発揮されない場合がある。(Problems to be Solved by the Invention) When a low-pass filter circuit of the F D N R circuit type is actually mounted on a circuit board, it may not exhibit its theoretical designed characteristics.
これは回路素子たる抵抗、コンデンサ等に微妙な誤差が
存在するためである。そこでどの抵抗を！Ｆｊ整すれば
周波数特性の適切な変化が得られるかどうか実験したと
ころ、前記した抵抗Ｒ１及び゛抵抗Ｒ２の抵抗値を変化
させても周波数特性はあまり変化せず、ＦＤＮＲ回路の
各素子の値を変化させろと、周波数特性は大きく変化す
ることが認められた。また各フィルタ部が設計上の周波
数特性を発揮する【ζは、伝達零点を設計上の計算値と
一致させれるようにＦＤＮＲ回路の回路素子を調整すれ
ば、フィルタ回路全体の周波数特性が設計値と一致する
ものである。This is because there are subtle errors in circuit elements such as resistors and capacitors. So what kind of resistance! When we conducted an experiment to see whether an appropriate change in frequency characteristics could be obtained by adjusting Fj, we found that even if we changed the resistance values of resistor R1 and resistor R2, the frequency characteristics did not change much, and the values of each element of the FDNR circuit It was observed that the frequency characteristics change significantly when the . In addition, each filter section exhibits the designed frequency characteristics [ζ] If the circuit elements of the FDNR circuit are adjusted so that the transmission zero point matches the design calculated value, the frequency characteristics of the entire filter circuit will be the designed value. This is consistent with the following.
しかし回路基板に各回路素子を組み込み、１次フィルタ
回路を実装した後、ＦＤＮＲ回路の回路素子例えば抵抗
部分をレーザートリミング等で抵抗値の調整を行おうと
しても、どのフィルタ部がどの伝達零点と対応するのか
明確でない場合もあり、誤ってトリミングする危険があ
る。例えば第６図（イ）はトリミング作業前のフィルタ
回路の周波数特性を示すグラフであるが、設計値では１
００ＫＨｚ、 ｌｌ０ＫＨｚ、 １２０ＫＨｚの伝達零
点が存在すべきなのに１００ＫＨｚ以下の伝達零点Ｐ−
，Ｐｂが２個計測され、１００ＫＨｚ〜１１０ＫＨｚの
間に残りの伝達零点Ｐ。が計測されると、伝達零点が１
００ＫＨｚとなるよう調整すべきフィルタ部と対応する
伝達零点がＰ、、Ｐｂのいずれであるか不明であり、更
には１１０ＫＨｚ及び１２０１’：Ｈｚに調整すべきフ
ィルタ部も特定できない。However, after assembling each circuit element on a circuit board and mounting a primary filter circuit, even if you try to adjust the resistance value of the circuit elements of the FDNR circuit, such as by laser trimming the resistor part, which filter part corresponds to which transmission zero point In some cases, it may not be clear whether the image is compatible, and there is a risk of accidentally trimming the image. For example, Figure 6 (a) is a graph showing the frequency characteristics of the filter circuit before trimming, but the design value is 1.
There should be a transmission zero point of 00KHz, 10KHz, 120KHz, but there is a transmission zero point P- of 100KHz or less.
, Pb are measured, and the remaining transmission zero point P between 100 KHz and 110 KHz. is measured, the transfer zero point becomes 1
It is unclear which of the transmission zero points P, .
（課題を解決するための手段）
本発明は前記課題を鑑み、周波数特性の調整を容易とし
、設計通りの特性を有するローパスフィルタを得る手段
を提案したものである。(Means for Solving the Problems) In view of the above problems, the present invention proposes a means for easily adjusting frequency characteristics and obtaining a low-pass filter having characteristics as designed.
本発明に係るローパスフィルタ装置は一１複数のＦＤＮ
Ｒ回路を有する連立チェピシェフ形フィルタを回路基板
上に形成するに際して、ＦＤＮＲ回路内の抵抗値を設計
値より小さくなるよう印刷形成すると共に、各ＦＤＮＲ
回路部分を予め電気的に分離して設けておき、各ＦＤＮ
Ｒ回路部分の周波数特性をチェックしながら前記ＦＤＮ
Ｒ回路内抵抗部分をトリミングして当該ＦＤＮＲ回路部
分の周波数特性を所望のものとした後、ＦＤＮＲ回路部
分の電気的分離部を接続して形成してなることを特徴と
するものである。The low-pass filter device according to the present invention includes one or more FDNs.
When forming a simultaneous Chepyshev type filter having an R circuit on a circuit board, the resistance value in the FDNR circuit is printed so as to be smaller than the design value, and each FDNR
The circuit parts are electrically separated in advance, and each FDN
While checking the frequency characteristics of the R circuit part,
This is characterized in that the resistance portion in the R circuit is trimmed to make the frequency characteristics of the FDNR circuit portion desired, and then the electrical isolation portion of the FDNR circuit portion is connected.
（作 用）
分離したＦＤＮＲ回路（フィルタ部）の構成素子である
抵抗をトリミングすると、他の回路からの影響を受けず
にＦＤＮＲ回路の周波数特性を個々に設計値に調整でき
、調整後面ＦＤＮＲ回路を接続するとフィルタ回路全体
の周波数特性も設計値通りの機能を発揮するものである
。(Function) By trimming the resistors that are the constituent elements of the separate FDNR circuit (filter section), the frequency characteristics of the FDNR circuit can be individually adjusted to the designed value without being influenced by other circuits, and the FDNR circuit after adjustment When connected, the frequency characteristics of the entire filter circuit function as designed.
（実施例） 次に本発明の実施例について説明する。(Example) Next, examples of the present invention will be described.
本発明にすするローパスフィルタ装置のフィルタ回路は
、第１図（イ）に示すようにＬＣ直列回路を並列態様に
、Ｌを直列態様に多段梯子状に接続した周知のものを、
ＬＣシュミレーシ買シン法、抵抗とＦＤＮＲ回路に置換
したものである。具体的には第１図（ロ）に示すように
入力と出力との間に直列態様抵抗Ｒ３，Ｒ５・・・・・
・と並列態様の直列する抵抗Ｒ翼。The filter circuit of the low-pass filter device according to the present invention is a well-known filter circuit in which LC series circuits are connected in parallel and L is connected in series in a multi-stage ladder shape, as shown in FIG.
The LC simulation method is replaced with a resistor and an FDNR circuit. Specifically, as shown in Figure 1 (b), series resistors R3 and R5 are connected between the input and output.
・Resistance R wing in series with parallel mode.
Ｒ４・・・・・・とＦＤＮＲ回路２ Ｋ、２、．２ 、
のコ状回路からなるフィルタ部Ａ、Ｂ、Ｃ，Ｄを４段設
けて所望の周波数特性を得るようにしたも（Ｆ）テ、Ｆ
ＤＮＲ回路Ｚ、、Ｚ、、Ｚｓの詳細及び回路全体の詳細
例は第２図に示す通りである。R4... and FDNR circuit 2 K, 2, . 2,
(F) Te, F
Details of the DNR circuits Z, , Z, , Zs and a detailed example of the entire circuit are as shown in FIG.
勿論前記回路自体は新規ではなく周知のものである。本
発明は前記回路の回路基板への実装手段に特徴を有する
ものである。Of course, the circuit itself is not new but well known. The present invention is characterized by means for mounting the circuit on a circuit board.
フィルタ回路を回路基板１に実装し、フィルタ装置を形
成するに際して、各構成素子（抵抗、コンデンサ、ＯＰ
アンプ等）を基板１に組み込むとき、ＦＤＮＲ回路 Ｚ
ｉｔ Ｚ ｔ＋ＺＪを構成する抵抗ｒｌｖ ’＊ｐ
’Ｊを予め設計上求めた抵抗値よ吟小さくなるよう基板
１に印刷形成する場合、設計値対応面積よりも１０％程
度大きく印刷しく印刷面積を広くすると電流の流れる幅
が広くなり流れ易くなるので抵抗値が小さくなる）
またフィルタ部Ａ、Ｂ、Ｃの内並列態様のＦＤＮＲ回路
直列抵抗Ｒ，、Ｒ，、Ｒ，の伝送回路側に電気的切断を
なす切断部イ２２ロ、ハ設け、ＦＤＮＲ回路回路２１，
２．．２．を含む構成部分を電気的に分離し、各独立し
た回＄８構成とし、而かる後分離したフィルタ部Ａ （
Ｒ，とＺｌの直列回路）に適宜な入力信号を加えてフィ
ルタ部Ａの伝達零点を見出しながらレーザトリミングを
し、前記伝達零点が設計値で定めた共振周波数Ｆ 、、
（１００ＸＩＩｌ）上に生ずるようにして、設旧値通
りの周波数特性を発揮する抵抗値に調整するものである
。周波数特性の伝達零点を求めながらのトリミングは、
作業上煩雑であるので、共振周波数での位相をチェック
しながら伝達零点を定めても良い。When mounting the filter circuit on the circuit board 1 to form a filter device, each component (resistor, capacitor, OP
amplifier, etc.) on the board 1, the FDNR circuit Z
it Z Resistance rlv composing t+ZJ '*p
When printing on the board 1 so that 'J is much smaller than the resistance value calculated in advance in the design, print the area about 10% larger than the area corresponding to the design value.If the printing area is widened, the width through which the current flows becomes wider and it becomes easier to flow. Therefore, the resistance value becomes smaller)
Furthermore, among the filter parts A, B, and C, cutting parts A22B and C are provided for electrically disconnecting the FDNR circuit series resistors R, , R, , R, in parallel mode on the transmission circuit side, and the FDNR circuit circuit 21,
2. ．． 2. The constituent parts including A are electrically separated, and each independent circuit is constructed, and then the separated filter part A (
A series circuit of R, and Zl) is applied with an appropriate input signal, and laser trimming is performed while finding the transmission zero point of the filter section A, and the transmission zero point is set to the resonance frequency F determined by the design value.
(100XIIl), and the resistance value is adjusted to a value that exhibits the frequency characteristics according to the old value. Trimming while finding the transmission zero point of frequency characteristics is
Since this is complicated, the transmission zero point may be determined while checking the phase at the resonance frequency.
次にフィルタ部への抵抗ｒ、のトリミングが終了すると
、順次フィルタ部Ｂ （Ｒ，とＺ。Next, when the trimming of the resistor r to the filter section is completed, the filter section B (R, and Z.
の直列回路）、フィルタ部Ｃ（Ｒ，と７３の直列回路）
の各トリミングを行い、第５図に示すように各フィルタ
部の周波数特性における伝達零点が設計値（２００ＫＨ
ｚ、 １１０に８２．１２０Ｋｌ１２）となり、而かる
後辺断部イ２ロ、へをハング等で接続するとフィルタ回
路が構成され、その周波数特性は前記フィルタＡ、 Ｂ
、Ｃの特性を重合した特性を得ることができるものであ
る（第６図）
尚前記実施例において切断個所イ、四２八ば特にＵｆＪ
路中乙の位置に特定されず、ＦＤＮＲ回路Ｚ１を含むも
のであれば良く、第３図ずれでも良い。また抵抗値を調
整する抵抗もＦＤＮＲ回路内の抵抗であればどの抵抗素
子を調整対象としても良い。更には第１図の例示したよ
うにフィルタ回路にＦＤＮＲ回路を有しないフィルタ部
りが組み込まれていても良く、本発明はＦＤＮＲ回路回
路が一つでも含まれるフィルタ部を有する連立チエビレ
エフ形フィルタであれば適用されるものである。series circuit), filter section C (series circuit of R, and 73)
As shown in Figure 5, the transmission zero point in the frequency characteristics of each filter section is set to the design value (200KH).
z, 110 and 82.120Kl12), and by connecting the rear cut-off parts A2 and B with a hang etc., a filter circuit is constructed, and its frequency characteristics are the same as those of the filters A and B.
, C can be obtained by polymerizing the characteristics of C (Fig. 6).
It is sufficient that the FDNR circuit Z1 is not specified at the location on the road and that it includes the FDNR circuit Z1, and it may be shifted from the position shown in FIG. Further, as long as the resistance for adjusting the resistance value is a resistor in the FDNR circuit, any resistance element may be the object of adjustment. Furthermore, as illustrated in FIG. 1, the filter circuit may incorporate a filter section that does not include an FDNR circuit, and the present invention provides a simultaneous Tiebeleev type filter that has a filter section that includes at least one FDNR circuit. If so, it will be applied.
（発明の効果）
以上のように本発明は、連立千人ビシエフ形フィルタに
於て、ＦＤＮＲ回路内の抵抗値を予め設君］値より小さ
く印刷形成すると共に、ＦＤＮＲ回路部分（フィルタ部
）を電気的に分離し、分離したＦＤＮＲ回路部分の周波
数特性を計測しつつ、トリミングをなし、前記抵抗値調
整し、設計上の特性と一致せしめた後、分離部を接続し
、フィルタ装置を形成するもので、誤調整が少なく且つ
調整作業自体も容易になるものである。(Effects of the Invention) As described above, the present invention prints and forms the resistance value in the FDNR circuit to be smaller than the predetermined value in the simultaneous 1,000-Bisiev type filter, and the FDNR circuit portion (filter portion). After electrically separating and measuring the frequency characteristics of the separated FDNR circuit parts, performing trimming and adjusting the resistance value to match the designed characteristics, the separated parts are connected to form a filter device. This reduces erroneous adjustments and makes the adjustment work itself easier.
第１図はフィルタ回路の簡便な回路図、第２図は同詳細
図、第３図はフィルタ部の構成例を示し、第４図は基板
実装状態を示し、第５図（よ各フィルタ部の調整前と調
整後の周波数特性のグラフであり、第６図（０（ｔ＋）
はフィルタ回路全体の周波数特性を示すグラフで、（？
）は調整前、（ロ）は調整後を示すものである。
１は回路基板
Ａ、Ａ、−、、−Ｂ、Ｃはフィルタ部
イ２ロ、八は切断部Figure 1 is a simple circuit diagram of the filter circuit, Figure 2 is a detailed diagram of the filter circuit, Figure 3 is a configuration example of the filter section, Figure 4 is a board mounted state, and Figure 5 (see below for each filter section). FIG. 6 is a graph of the frequency characteristics before and after adjustment of (0(t+)
is a graph showing the frequency characteristics of the entire filter circuit, (?
) indicates before adjustment, and (b) indicates after adjustment. 1 is the circuit board A, A, -, , -B, C is the filter section A, 2 B, and 8 is the cutting section.
Claims (1)
フィルタを回路基板上に形成する に際して、ＦＤＮＲ回路内の抵抗値を設計 値より小さくなるよう印刷形成すると共に 各ＦＤＮＲ回路部分を予め電気的に分離し て設けておき、各ＦＤＮＲ回路部分の周波 数特性をチェックしながら前記ＦＤＮＲ回 路内抵抗部分をトリミングして当該ＦＤＮ Ｒ回路部分の周波数特性を所望のものとし た後、ＦＤＮＲ回路部分の電気的分離部を 接続して形成してなることを特徴とするロ ーパスフィルタ装置。(1) When forming a simultaneous Chepyshev filter having multiple FDNR circuits on a circuit board, the resistance value in the FDNR circuit is printed so as to be smaller than the designed value, and each FDNR circuit part is electrically isolated in advance. After trimming the resistance portion in the FDNR circuit while checking the frequency characteristics of each FDNR circuit portion to obtain the desired frequency characteristics of the FDNR circuit portion, the electrical isolation portion of the FDNR circuit portion is trimmed. A low-pass filter device characterized in that it is formed by connecting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63303341A JPH088463B2 (en) | 1988-11-30 | 1988-11-30 | Method for manufacturing low-pass filter device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63303341A JPH088463B2 (en) | 1988-11-30 | 1988-11-30 | Method for manufacturing low-pass filter device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02149120A true JPH02149120A (en) | 1990-06-07 |
| JPH088463B2 JPH088463B2 (en) | 1996-01-29 |
Family
ID=17919806
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63303341A Expired - Lifetime JPH088463B2 (en) | 1988-11-30 | 1988-11-30 | Method for manufacturing low-pass filter device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH088463B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010511312A (en) * | 2006-11-27 | 2010-04-08 | トムソン ライセンシング | Active low-pass filter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5379452A (en) * | 1976-12-24 | 1978-07-13 | Hitachi Denshi Ltd | Band pass filter |
-
1988
- 1988-11-30 JP JP63303341A patent/JPH088463B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5379452A (en) * | 1976-12-24 | 1978-07-13 | Hitachi Denshi Ltd | Band pass filter |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010511312A (en) * | 2006-11-27 | 2010-04-08 | トムソン ライセンシング | Active low-pass filter |
| US8878631B2 (en) | 2006-11-27 | 2014-11-04 | Thomas Licensing | Active low pass filter |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH088463B2 (en) | 1996-01-29 |
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