JPS6091718A - Waveform shaping circuit - Google Patents

Waveform shaping circuit

Info

Publication number
JPS6091718A
JPS6091718A JP20021283A JP20021283A JPS6091718A JP S6091718 A JPS6091718 A JP S6091718A JP 20021283 A JP20021283 A JP 20021283A JP 20021283 A JP20021283 A JP 20021283A JP S6091718 A JPS6091718 A JP S6091718A
Authority
JP
Japan
Prior art keywords
level
signal
input signal
waveform shaping
operational amplifier
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
Application number
JP20021283A
Other languages
Japanese (ja)
Inventor
Takeshi Kamogawa
鴨川　威
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Priority to JP20021283A priority Critical patent/JPS6091718A/en
Publication of JPS6091718A publication Critical patent/JPS6091718A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/023—Generators characterised by the type of circuit or by the means used for producing pulses by the use of differential amplifiers or comparators, with internal or external positive feedback
    • H03K3/0233—Bistable circuits
    • H03K3/02337—Bistables with hysteresis, e.g. Schmitt trigger

Landscapes

  • Manipulation Of Pulses (AREA)

Abstract

PURPOSE:To obtain a waveform shaping circuit where the phase of an output signal is not changed even if an input signal level is changed by changing a threshold level in response to the detected output of a peak hold means to an input signal. CONSTITUTION:An operational amplifier 13 converts an input signal into a rectangular wave signal and leads the signal to an output terminal 14 while being operated in the saturated and non-saturated state in response to the level of the input signal applied to its inverting input terminal. An operational amplifier 21 is activated at the active region and amplifiers an input signal V1, the amplified signal is subject to peak detection by the rectifying and smoothind operation of a diode 23 and a capacitor 25 and the detected voltage is held in the capacitor 25. A Schmitt voltage inputted to a non-inverting input terminal of the operational amplifier 13 becomes the sum of the detected voltage and a feedback voltage formed by resistors 17, 18 and since it is changed in repsonse to a peak level of the input signal V1, even if the level of the input signal is changed, a waveform shaping circuit where the phase of output signal is unchanged is realized.

Description

【発明の詳細な説明】 〔発明の技術分野〕 この発明は波形整形用の波形整形回路に関する。[Detailed description of the invention] [Technical field of invention] The present invention relates to a waveform shaping circuit for waveform shaping.

〔発明の技術的背景〕[Technical background of the invention]

例えばビデオテープレコーダに於いては、各種モータの
回転速度を検出するのに使われるＦＧ（周波数ジェネレ
ータ）信号やＰＧ（−ルスジェネレータ）信号、あるい
はコントロール信号の再生出力をその処理回路に入力す
る際に、予じめ波形整形する必要がある。この為の波形
整形回路としては、一般に第１図に示すようなシュミッ
ト回路がよく用いられる。For example, in a video tape recorder, when inputting FG (frequency generator) signals, PG (-lux generator) signals used to detect the rotational speed of various motors, or the playback output of control signals to the processing circuit. Therefore, it is necessary to shape the waveform in advance. As a waveform shaping circuit for this purpose, a Schmitt circuit as shown in FIG. 1 is generally used.

図示のシュミット回路はオペアンプを用いたシュミット
回路で、１ノは入力端子、１２は入力抵抗、１３はオペ
アンプ、１４は出力端子、１５は帰還抵抗、１６．１７
はバイアス抵抗である。The Schmitt circuit shown is a Schmitt circuit using an operational amplifier, 1 is an input terminal, 12 is an input resistance, 13 is an operational amplifier, 14 is an output terminal, 15 is a feedback resistor, 16.17
is the bias resistance.

オペアンプ１３は反転入力端子（−入力端子）に供給さ
れる入力信号のレベルに応じて、飽和。The operational amplifier 13 is saturated depending on the level of the input signal supplied to the inverting input terminal (-input terminal).

非飽和状態で動作することにより、入力信号全矩形波信
号に変換して出力端子１４に導び〈。By operating in a non-saturated state, the input signal is converted into a full square wave signal and guided to the output terminal 14.

この場合、オペアンプ１３は帰還抵抗１５の正帰還作用
によりヒステリシス特性をもつようになる。In this case, the operational amplifier 13 has hysteresis characteristics due to the positive feedback action of the feedback resistor 15.

第２図に示す如く、入力信号ｖ１のレベルが低いときは
、出力信号Ｖ。のレベルは高いから、このときのオにア
ンプ１３の非反転入力端子の電圧、スレッショルドレベ
ル（以下、シーミツトレベルという）　”ＴＩは。As shown in FIG. 2, when the level of the input signal v1 is low, the output signal V. Since the level of is high, the voltage at the non-inverting input terminal of the amplifier 13 at this time is the threshold level (hereinafter referred to as the seamit level).

１ ｖＴＨ＝　酊様、　’　ＶＯＨ’値１）但し、Ｒ１：抵
抗１６の抵抗値 Ｒ２：抵抗１５の抵抗（ｉｌ′］ ＶｏＨ：高レベルの出力信号レベル となる。入力信号ｖ１のレベルが上昇し７て、ｖＴＨレ
ベルとなると、出方信号Ｖ。は低レベルＶ。Ｌとなる。1 vTH= Drunk, 'VOH' value 1) However, R1: Resistance value of resistor 16 R2: Resistance of resistor 15 (il') VoH: High level output signal level.When the level of input signal v1 rises 7, when it reaches the vTH level, the output signal V. becomes a low level V.L.

これがオペアンｆ１．？の非反転入力端子に正帰還され
る為、出力信号Ｖ。の立ち上がりは早くなる。このとき
の非反転入力端子の電圧ｖＴＬは。This is opian f1. ? The output signal V is positive feedback to the non-inverting input terminal of. starts up faster. The voltage vTL at the non-inverting input terminal at this time is.

１ ｖＴＬ＝−一・ｖｏＬ・・・（２） Ｒ１十Ｒ２ となり、これが入力信号Ｖ、のレベルが減少するときの
シーミツトレベルとなる。入力信号ＶＸのレベルが減少
して”ＴＬになると、オペアンプ１３の出力信号レベル
はＶ。Ｈとなる。これが非反転入力端子は正帰還される
為、出方信号Ｖの立ち上がりが早くなる。1 vTL=-1·voL (2) R10R2 This becomes the seamit level when the level of the input signal V decreases. When the level of the input signal VX decreases to "TL", the output signal level of the operational amplifier 13 becomes V.H. Since this is positively fed back to the non-inverting input terminal, the output signal V rises quickly.

このようなシュミット回路によれば、シーミントレベル
ｖＴＨ９ＶＴＬ内の雑音成分が出力信号Ｖｏにノックあ
るｂけリンギングとして現れなりので、高品位の波形整
形出力が得られる。According to such a Schmitt circuit, the noise component in the seamint level vTH9VTL appears as knocking and ringing in the output signal Vo, so that a high-quality waveform-shaped output can be obtained.

〔背景技術の問題点〕[Problems with background technology]

しかしながら、上記構成の場合、シュミットレベル■Ｔ
Ｈあるいは■ＴＬが一定の為、入力信号ｖＩにレベル変
動があると入力信号■１□、ｖ１２、出力信号Ｖ。に位
相変動が生じる出方信号Ｖ　。However, in the case of the above configuration, Schmidt level ■T
Since H or ■TL is constant, if there is a level change in the input signal vI, the input signal ■1□, v12, and the output signal V. The output signal V in which a phase fluctuation occurs.

１ ｖｏ２・ 具体的な問題として、例えばビデオテープレコーダに於
すて、磁気テープとして蒸着型メタルテープ（ＭＥテー
プ）全使用した場合と塗布型メタルチーニア’（ＭＰチ
ーｆ）を使用した場合とでは、再生コントロール信号に
約］ＯｄＢのレベル差が生じる。このレベル差の為に、
回転磁気ヘッドのトラッキング位相にずれが生じる為、
一般には各テープに合った特性のシュミット回路を予め
設けるようにしている。1 vo2. As a concrete problem, for example, in a video tape recorder, when all vapor-deposited metal tape (ME tape) is used as the magnetic tape, and when coated metal tape (MP tape) is used, A level difference of approximately ]OdB occurs in the reproduction control signal. Because of this level difference,
Due to a shift in the tracking phase of the rotating magnetic head,
Generally, a Schmitt circuit with characteristics suitable for each tape is provided in advance.

〔発明の目的〕[Purpose of the invention]

この発明は上記の事情に対処すべくなされたもので、入
力信号のレベルに変動が生じても、出力信号の位相変動
が生じない波形整形回路を提供することを目的とする。The present invention has been made in order to cope with the above-mentioned situation, and an object of the present invention is to provide a waveform shaping circuit in which the phase of the output signal does not fluctuate even if the level of the input signal fluctuates.

〔発明の概要〕[Summary of the invention]

この発明は、入力信号のピーク値を検波し、これをホー
ルドするピークホールド手段を設け、このピークホール
ド手段の検波出力に応じてスレッショルドレベルを変化
さぜるように構成したものである。The present invention is configured to include peak hold means for detecting and holding the peak value of an input signal, and to change the threshold level in accordance with the detected output of the peak hold means.

〔発明の実施例〕[Embodiments of the invention]

以下、図面全参照してこの発明の一実施例を詳細に説明
する。Hereinafter, one embodiment of the present invention will be described in detail with reference to all the drawings.

第３図は一実施例の回路図である。なお、第３図に於い
て、先の第１図と同一部には同一符号’ｔ（”ｌす。図
示の回路は先の第１図の回路にオペアンプ２）、抵抗２
２、ダイオード２３、抵抗２４、コンデンサ２５から成
るピークホールド回路を設けたものである。FIG. 3 is a circuit diagram of one embodiment. In addition, in FIG. 3, the same parts as those in the previous FIG.
2. A peak hold circuit consisting of a diode 23, a resistor 24, and a capacitor 25 is provided.

各部の接続構成を説明すると、入力端子Ｉノはオペアン
プ２１の非反転入力端子に接続され、このオペアン７”
２１の出力端子は抵抗２２を介してダイオード２３のア
ノードに接続されている。ダイオード２３のカソードは
抵抗２４を介して接地されるとともに、コンデンサ２５
を介して接地される。ダイオード２３のカソード、抵抗
２４、コンデンサ２５の接続点はオペアンプ２１の反転
入力端子に接続されるとともに、前記抵抗１６ｆ介して
前記オペアンプ１３の非反転入力端子に接続されている
。To explain the connection configuration of each part, the input terminal I is connected to the non-inverting input terminal of the operational amplifier 21, and the operational amplifier 7''
The output terminal of 21 is connected to the anode of a diode 23 via a resistor 22. The cathode of the diode 23 is grounded via a resistor 24 and connected to a capacitor 25.
grounded through. A connection point between the cathode of the diode 23, the resistor 24, and the capacitor 25 is connected to the inverting input terminal of the operational amplifier 21, and is also connected to the non-inverting input terminal of the operational amplifier 13 via the resistor 16f.

上記構成に於いて動作全説明する。オペアンｆ２Ｊは能
動領域で動作し、入力信号ｖ、２増幅する。この増幅信
号はダイオード２３、コンデンサ２５の整流平滑作用に
よりピーク検波され、この検波電圧Ｖ。がコンデンサ２
５にホールドされる。The entire operation in the above configuration will be explained. The operational amplifier f2J operates in the active region and amplifies the input signal v,2. This amplified signal is peak-detected by the rectifying and smoothing action of a diode 23 and a capacitor 25, and this detected voltage V. is capacitor 2
It is held at 5.

この場合のシーミツトレベルｖＴＨは次式（３）に表わ
される。The seamit level vTH in this case is expressed by the following equation (3).

ここで、一般にシュミット回路はＲ２＞Ｒ４と選ばレル
（例エバＶ□Ｈ’ｆｃ　５１：Ｖ］ｐｅａｋとすれば、
”ＴＨは数１０［ｍＶｌ）とされる〕ため。Here, in general, if the Schmitt circuit is selected as R2>R4 (e.g. Eva V□H'fc 51:V]peak, then
``Because TH is considered to be several tens [mVl].

ｖＴＨ”　ｖＧ　−（４） となる。vTH" vG - (4) becomes.

また検波電圧Ｖ。は ｖ＝に−ｖ１Ｐ・・・（５） 但し、■、、二人力信号ｖ１の一一りレベルＫ　：定数 となる。従って、シュミットレベル■ＴＨハ入力信号Ｖ
□のピークレベルに応じて変化する。Also, the detection voltage V. is v=−v1P...(5) However, ■, the first level K of the two-person force signal v1: is a constant. Therefore, the Schmitt level ■TH is the input signal V
Changes according to the peak level of □.

したがって、第４図に示すように、入力信号ｖ１のレベ
ルがｖＩＩ　＊　ｖ１２のように変化していても、出力
信号Ｖ。の位相はＶ。１．ｖ０２に示すようにほとんど
変化しない。Therefore, as shown in FIG. 4, even if the level of the input signal v1 changes as vII*v12, the output signal V. The phase of is V. 1. As shown in v02, there is almost no change.

なお、この発明はオペアンプを用いたシュミット回路だ
けでなく、例えばトランジスタの直結増幅段に正帰還を
かけるような構成のシュミット回路にも実施可能々こと
は勿論である。It should be noted that the present invention can of course be implemented not only in a Schmitt circuit using an operational amplifier but also in a Schmitt circuit configured such that positive feedback is applied to a direct-coupled amplifier stage of transistors, for example.

また、第３図の回路は立上り、立下りでシュミットレベ
ルが異なるものであるが、両レベルが同一のいわゆるシ
ュミ、、トヲかけない回路形式にも適用可能である。Further, although the circuit shown in FIG. 3 has different Schmitt levels at rising and falling edges, it can also be applied to a circuit type in which both levels are the same, so-called Schmidt level is not applied.

〔発明の効果〕〔Effect of the invention〕

このようにこの発明によれば、入力信号のレベルが変化
しても、出力信号の位相が変化しない波形整形回路全提
供することができる。As described above, according to the present invention, it is possible to provide an entire waveform shaping circuit in which the phase of the output signal does not change even if the level of the input signal changes.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来のシュミット回路を示す回路図、第２図は
第１図の動作を説明する為の信号波形図、第３図はこの
発明に係る波形整形回路の一実施例を示す回路図、第４
図は第３図の動作を説明する為の信号波形図である。 １１・・・入力端子、１２，１５，１６，１７゜２２．
２４・・・抵抗、１３．２１・・・オペアンプ、１４・
・・出力端子、２３・・・ダイオード、２４・・・コン
デンサ。 出願人代理人　弁理士　鈴　江　武　彦第１図 第２図 第４図Fig. 1 is a circuit diagram showing a conventional Schmitt circuit, Fig. 2 is a signal waveform diagram for explaining the operation of Fig. 1, and Fig. 3 is a circuit diagram showing an embodiment of the waveform shaping circuit according to the present invention. , 4th
The figure is a signal waveform diagram for explaining the operation of FIG. 3. 11... Input terminal, 12, 15, 16, 17°22.
24... Resistor, 13.21... Operational amplifier, 14.
...output terminal, 23...diode, 24...capacitor. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 4

Claims (1)

【特許請求の範囲】 一方の入力端子に入力信号が印加され、他方の入力端子
に出力信号が正帰還され、入力信号のレベルに応じて飽
和、非飽和動作することによシ、入力信号を矩形波信号
として出力する波形整形手段と。 前記入力信号のピーク値を検波、ホールドし、その検波
出力を前記波形整形手段の他方の入力端子に供給するピ
ークホールド手段とを具備した波形整形回路。[Claims] The input signal is applied to one input terminal, the output signal is positively fed back to the other input terminal, and the input signal is saturated or desaturated depending on the level of the input signal. A waveform shaping means for outputting a rectangular wave signal. A waveform shaping circuit comprising peak hold means for detecting and holding a peak value of the input signal and supplying the detected output to the other input terminal of the waveform shaping means.
JP20021283A 1983-10-26 1983-10-26 Waveform shaping circuit Pending JPS6091718A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP20021283A JPS6091718A (en) 1983-10-26 1983-10-26 Waveform shaping circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP20021283A JPS6091718A (en) 1983-10-26 1983-10-26 Waveform shaping circuit

Publications (1)

Publication Number Publication Date
JPS6091718A true JPS6091718A (en) 1985-05-23

Family

ID=16420676

Family Applications (1)

Application Number Title Priority Date Filing Date
JP20021283A Pending JPS6091718A (en) 1983-10-26 1983-10-26 Waveform shaping circuit

Country Status (1)

Country Link
JP (1) JPS6091718A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3824557A1 (en) * 1988-07-20 1990-01-25 Thomson Brandt Gmbh CIRCUIT FOR CONVERSION

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3824557A1 (en) * 1988-07-20 1990-01-25 Thomson Brandt Gmbh CIRCUIT FOR CONVERSION

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