JPH09238036A - Electronic volume circuit - Google Patents
Electronic volume circuitInfo
- Publication number
- JPH09238036A JPH09238036A JP8043688A JP4368896A JPH09238036A JP H09238036 A JPH09238036 A JP H09238036A JP 8043688 A JP8043688 A JP 8043688A JP 4368896 A JP4368896 A JP 4368896A JP H09238036 A JPH09238036 A JP H09238036A
- Authority
- JP
- Japan
- Prior art keywords
- reference voltage
- voltage
- differential amplifier
- level
- variable reference
- 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
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000005236 sound signal Effects 0.000 description 5
- 230000002238 attenuated effect Effects 0.000 description 2
- 230000035807 sensation Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Landscapes
- Control Of Amplification And Gain Control (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、制御信号のレベル
に応じて入力信号のレベルを調整する電子ボリューム回
路に関するもので、特にＤ/Ａ変換後のアナログ制御信
号に応じて音声信号を自然な調子でレベル調整できる電
子ボリューム回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic volume circuit which adjusts the level of an input signal according to the level of a control signal, and more particularly to a natural audio signal according to an analog control signal after D / A conversion. The present invention relates to an electronic volume circuit whose level can be adjusted by tone.
【０００２】[0002]
【従来の技術】最近の音響機器や映像機器では複数のＩ
Ｃを機器内に備えるが、該ＩＣのコントロールは機器内
のマイクロコンピュータからのデジタル信号により行わ
れることが多い。そして、前記ＩＣ内部もしくは外部に
Ｄ/Ａ（デジタル/アナログ）変換器を配置している。こ
のようなマイクロコンピュータからのデジタル信号制御
の対象として電子ボリュームがある。電子ボリューム
は、制御信号のレベルに応じて入力信号のレベルを調整
するものである。2. Description of the Related Art In recent audio and video equipment, a plurality of I
Although C is provided in the device, control of the IC is often performed by a digital signal from a microcomputer in the device. A D / A (digital / analog) converter is arranged inside or outside the IC. An electronic volume is an object of digital signal control from such a microcomputer. The electronic volume adjusts the level of the input signal according to the level of the control signal.
【０００３】図２は、そのような電子ボリュームを示す
ものである。音声入力信号は、入力端子（１）から印加
され利得が変化するＧＣＡ（２）でレベル調整される。
ＧＣＡ（２）でレベル調整された信号は、出力端子
（３）に導出される。ＧＣＡ（２）の利得は、マイクロ
コンピュータ（４）からのデジタル信号で制御される。
マイクロコンピュータ（４）からのデジタル信号は、シ
リアル形式で出力され、変換器（５）でパラレル形式に
変換される。パラレル形式のデジタル信号は、Ｄ/Ａ変
換器（６）でアナログ信号に変換される。変換されたア
ナログ信号は、制御信号に応じて基準電圧が変化する可
変基準電圧源（７）に印加される。そして、可変基準電
圧源（７）の基準電圧の変化に応じて制御回路（８）か
ら発生する制御信号のレベルが変化し、ＧＣＡ（２）の
利得が変化する。FIG. 2 shows such an electronic volume. The level of the audio input signal is adjusted by the GCA (2) which is applied from the input terminal (1) and whose gain changes.
The signal whose level has been adjusted by the GCA (2) is led to the output terminal (3). The gain of the GCA (2) is controlled by the digital signal from the microcomputer (4).
The digital signal from the microcomputer (4) is output in serial format and converted into parallel format by the converter (5). The parallel digital signal is converted into an analog signal by the D / A converter (6). The converted analog signal is applied to the variable reference voltage source (7) whose reference voltage changes according to the control signal. Then, the level of the control signal generated from the control circuit (8) changes according to the change of the reference voltage of the variable reference voltage source (7), and the gain of the GCA (2) changes.
【０００４】可変基準電圧源（７）の基準電圧値とＧＣ
Ａ（２）の利得の関係を図３の実線に示す。可変基準電
圧源（７）の基準電圧値を下げると減衰量が増してい
く。図３において、−１００ｄＢは、音声信号のレベル
がゼロであるとみなす。図３の実線に沿って記載された
階段状の波形は、Ｄ/Ａ変換器（６）のデジタル信号の
ステップを示す。通常、Ｄ/Ａ変換器（６）には５ビッ
トの制御信号が印加され３２通りのステップとなる。Reference voltage value of variable reference voltage source (7) and GC
The solid line in FIG. 3 shows the gain relationship of A (2). When the reference voltage value of the variable reference voltage source (7) is lowered, the amount of attenuation increases. In FIG. 3, −100 dB is regarded as the level of the audio signal being zero. The step-like waveform described along the solid line in FIG. 3 indicates the steps of the digital signal of the D / A converter (6). Normally, a 5-bit control signal is applied to the D / A converter (6), and there are 32 steps.
【０００５】従って、図２の回路によれば、マイクロコ
ンピュータからのデジタル信号制御により電子ボリュー
ムをコントロールできる。Therefore, according to the circuit of FIG. 2, the electronic volume can be controlled by the digital signal control from the microcomputer.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、図２の
回路では音声信号を自然な調子で減衰できない、という
問題があった。図２の回路では、０ｄＢから−１００ｄ
Ｂまでの広い範囲に渡ってわずか３２ステップでコント
ロールしなければならない。このため、音声のレベルが
大きく減衰させた場合にその変化が明瞭に解る−３０ｄ
Ｂ程度以上の減衰率の範囲でのステップが十分に確保で
きない。すると、聴取者が音響機器のボリュームを大音
量から下げた時に音量が急に下がってしまい、違和感が
でてしまう、という問題があった。However, the circuit of FIG. 2 has a problem that the audio signal cannot be attenuated in a natural tone. In the circuit of FIG. 2, 0 dB to −100 d
It has to be controlled in only 32 steps over a wide range up to B. Therefore, when the sound level is greatly attenuated, the change can be clearly understood.
Sufficient steps cannot be secured in the range of the attenuation rate of about B or higher. Then, when the listener lowers the volume of the audio device from the large volume, the volume suddenly drops, which causes a feeling of strangeness.
【０００７】[0007]
【課題を解決するための手段】本発明は、上述の点に鑑
みなされたもので、電子ボリュームの制御量に応じて基
準電圧が変化する可変基準電圧源と、一端に前記可変基
準電圧源の電圧が印加される抵抗と、エミッタが前記抵
抗の他端に接続されベースに定電圧が印加されるトラン
ジスタを含む電流発生回路と、該電流発生回路の出力電
流に応じて動作する差動増幅器と、該差動増幅器の出力
信号に応じて入力信号のレベルを調整するＧＣＡと、前
記可変基準電圧源の電圧が所定値になったことを検出
し、その検出出力信号に応じて前記差動増幅器の出力信
号の状態を強制的に切り換える切り替え制御回路とを備
えることを特徴とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a variable reference voltage source whose reference voltage changes in accordance with the control amount of an electronic potentiometer and one end of the variable reference voltage source. A resistor to which a voltage is applied, a current generating circuit including a transistor whose emitter is connected to the other end of the resistor and a constant voltage is applied to the base, and a differential amplifier which operates according to the output current of the current generating circuit. A GCA for adjusting the level of an input signal according to an output signal of the differential amplifier, and detecting that the voltage of the variable reference voltage source has reached a predetermined value, and the differential amplifier according to the detected output signal. And a switching control circuit for forcibly switching the state of the output signal.
【０００８】[0008]
【発明の実施の形態】図１は、本発明の電子ボリューム
回路を示すもので、（９）は一端に可変基準電圧源
（７）の電圧が印加される抵抗、（１０）はエミッタが
前記抵抗（９）の他端に接続されベースに定電圧が印加
されるトランジスタ（１１）と定電流源（１２）（１
３）と電流ミラー回路（１４）とを含み前記抵抗（９）
に流れる電流ｉと等しい電流ｉを発生する電流発生回
路、（１５）は電流発生回路（１０）の出力電流に応じ
て動作する差動増幅器、（１６）は差動増幅器（１５）
の出力信号に応じて信号源（１７）からの入力信号のレ
ベルを調整するＧＣＡ、（１８）は前記可変基準電圧源
（７）の電圧が所定値以下になったことを検出し、その
検出出力信号に応じて前記差動増幅器（１５）の出力端
子（１９）（２０）の出力信号の状態を強制的に「Ｌ」
レベルに切り換える切り替えトランジスタである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an electronic volume circuit of the present invention. (9) is a resistor to which the voltage of a variable reference voltage source (7) is applied, and (10) is an emitter. A transistor (11) connected to the other end of the resistor (9) and having a constant voltage applied to the base, and a constant current source (12) (1
3) and the current mirror circuit (14), and the resistor (9)
A current generating circuit for generating a current i equal to the current i flowing through the current generating circuit, (15) a differential amplifier operating according to the output current of the current generating circuit (10), (16) a differential amplifier (15)
The GCA (18) for adjusting the level of the input signal from the signal source (17) according to the output signal of (7) detects that the voltage of the variable reference voltage source (7) has become a predetermined value or less, and the detection thereof. The state of the output signals of the output terminals (19) and (20) of the differential amplifier (15) is forcibly set to "L" according to the output signal.
It is a switching transistor that switches to a level.
【０００９】尚、図１において、図２と同一の回路素子
については同一の符号を付し、説明を省略する。可変基
準電圧源（７）の基準電圧値とＧＣＡ（１６）の利得の
関係を図４の実線に示す。可変基準電圧源（７）の基準
電圧値を下げると減衰量が増していく。図４に示される
ように図１の回路では電圧ＶＡを境に動作が異なる。即
ち、電圧ＶＡ以上では通常の減衰カーブを描き、電圧Ｖ
Ａ以下ではミュートさせている。前記電圧ＶＡは、−５
０ｄＢ前後に設定される。通常、−５０ｄＢ程度が聴取
者に聞こえる限度である。そのため、これ以下のレベル
については階段状のコントロールを行わず、いきなりミ
ュートしてしまう。それにより、−５０ｄＢ程度から０
ｄＢの範囲で、３２通りのステップを全て使用すること
が可能となるので、その範囲（大きい音量）におけるス
テップが細かくなり、電子ボリューム全体としての聴感
が自然なものとなる。In FIG. 1, the same circuit elements as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. The relationship between the reference voltage value of the variable reference voltage source (7) and the gain of the GCA (16) is shown by the solid line in FIG. When the reference voltage value of the variable reference voltage source (7) is lowered, the amount of attenuation increases. As shown in FIG. 4, the circuit of FIG. 1 operates differently at the voltage VA. That is, at a voltage VA or higher, a normal attenuation curve is drawn, and the voltage V
Below A, it is muted. The voltage VA is -5
It is set to around 0 dB. Usually, about -50 dB is the limit at which a listener can hear. Therefore, for levels below this level, the stepwise control is not performed and the sound is muted suddenly. As a result, from -50 dB to 0
Since it is possible to use all 32 steps in the dB range, the steps in the range (loud volume) are fine, and the sensation of the electronic volume as a whole becomes natural.
【００１０】具体的には、可変基準電圧源（７）の電圧
がＶＡ以下となると、切り替えトランジスタ（１８）が
オンし、差動増幅器（１５）の出力端子（１９）の電圧
が「Ｌ」レベルとなりＧＣＡ（１６）をミュートするこ
とにより行われる。まず、可変基準電圧源（７）の電圧
が所定値ＶＡ以上である場合について説明する。この場
合には、切り替えトランジスタ（１８）は、オフしてい
る。いま、定電圧源（２１）の電圧に対して可変基準電
圧源（７）の電圧が等しいとすると、抵抗（９）には電
流が流れない。トランジスタ（１１）とトランジスタ
（２６）の立ち上がり電圧は等しいとする。Specifically, when the voltage of the variable reference voltage source (7) becomes VA or less, the switching transistor (18) is turned on and the voltage of the output terminal (19) of the differential amplifier (15) is "L". This is done by muting the GCA (16) at the level. First, the case where the voltage of the variable reference voltage source (7) is equal to or higher than the predetermined value VA will be described. In this case, the switching transistor (18) is off. Now, assuming that the voltage of the variable reference voltage source (7) is equal to the voltage of the constant voltage source (21), no current flows through the resistor (9). It is assumed that the transistors (11) and (26) have the same rising voltage.
【００１１】すると、定電流源（１２）の電流がトラン
ジスタ（１１）に流れ、更に電流ミラー回路（１４）に
流れる。定電流源（１２）の電流と定電流源（１３）の
電流は、等しくなるように設定されているので端子（２
２）には電流が流れない。端子（２２）に電流が流れな
ければ、差動増幅器（１５）を構成するトランジスタ
（２３）（２４）のベースには基準電圧源（２５）から
等しい電圧が印加される。トランジスタ（２３）（２
４）のベース電圧が等しければ出力端子（１９）（２
０）の出力信号のレベルも等しくなる。出力端子（１
９）（２０）の出力信号のレベルが等しければ、ＧＣＡ
（１６）の利得は中間値となる。そのため、信号源（１
７）からの入力信号のレベルが中間値の利得で増幅され
て出力端子（３）に得られる。Then, the current of the constant current source (12) flows through the transistor (11) and further through the current mirror circuit (14). Since the current of the constant current source (12) and the current of the constant current source (13) are set to be equal, the terminal (2
No current flows in 2). If no current flows through the terminal (22), an equal voltage is applied from the reference voltage source (25) to the bases of the transistors (23) and (24) that form the differential amplifier (15). Transistor (23) (2
If the base voltages of 4) are equal, the output terminals (19) (2
The output signals of 0) are also equal in level. Output terminal (1
9) If the output signal levels of (20) are equal, GCA
The gain of (16) is an intermediate value. Therefore, the signal source (1
The level of the input signal from 7) is amplified with an intermediate gain and obtained at the output terminal (3).
【００１２】この状態から、可変基準電圧源（７）の電
圧を上げたとすると、抵抗（９）から電流ｉが定電流源
（１２）に流れる。すると、トランジスタ（１１）のエ
ミッタ電流が電流ｉだけ減少し、電流ミラー回路（１
４）の端子（２７）の電流も電流ｉが減る。その結果、
基準電圧源（２５）から電流ｉが端子（２２）を介して
定電流源（１３）に流れ、トランジスタ（２３）のベー
ス電圧が低下する。トランジスタ（２３）のベース電圧
が低下すると、出力端子（１９）の出力信号のレベルが
上がり、出力端子（２０）の出力信号のレベルが下が
る。すると、ＧＣＡ（１６）の利得が上昇し、信号源
（１７）からの入力信号のレベルが高い利得で増幅され
て出力端子（３）に得られる。If the voltage of the variable reference voltage source (7) is raised from this state, the current i flows from the resistor (9) to the constant current source (12). Then, the emitter current of the transistor (11) decreases by the current i, and the current mirror circuit (1
The current i of the terminal (27) of 4) also decreases. as a result,
A current i flows from the reference voltage source (25) through the terminal (22) to the constant current source (13), and the base voltage of the transistor (23) decreases. When the base voltage of the transistor (23) decreases, the level of the output signal of the output terminal (19) increases and the level of the output signal of the output terminal (20) decreases. Then, the gain of the GCA (16) is increased, and the level of the input signal from the signal source (17) is amplified with a high gain and obtained at the output terminal (3).
【００１３】この際のＧＣＡ（１６）の利得は、−５０
ｄＢ程度から０ｄＢの範囲で、３１通りのステップを使
用することが可能となるので、その範囲（大きい音量）
におけるステップが細かくなり、電子ボリューム全体と
しての聴感が自然なものとなる。次に、可変基準電圧源
（７）の電圧が所定値ＶＡ以下である場合について説明
する。この場合には、切り替えトランジスタ（１８）が
オンする。切り替えトランジスタ（１８）がオンする
と、出力端子（１９）の出力信号のレベルが「Ｌ」レベ
ルに下がる。すると、ＧＣＡ（１６）の利得が−１００
ｄＢ、即ちミュート状態となり、信号源（１７）からの
入力信号のレベルがミュートされて出力端子（３）には
信号が表れない。The gain of the GCA (16) at this time is -50.
It is possible to use 31 different steps in the range of about dB to 0 dB, so that range (large volume)
The steps in become finer, and the sensation of the electronic volume as a whole becomes natural. Next, a case where the voltage of the variable reference voltage source (7) is equal to or lower than the predetermined value VA will be described. In this case, the switching transistor (18) is turned on. When the switching transistor (18) is turned on, the level of the output signal of the output terminal (19) drops to the “L” level. Then, the gain of GCA (16) is -100.
dB, that is, the mute state, the level of the input signal from the signal source (17) is muted, and no signal appears at the output terminal (3).
【００１４】従って、図１の回路によればＤ/Ａ変換後
のアナログ制御信号に応じて音声信号を自然な調子でレ
ベル調整できる図５は、図１のＧＣＡ（１６）の具体回
路例を示すもので、図５において、図１と同一の回路素
子については同一の符号を付し、説明を省略する。図５
の回路は、出力端子（３）の直流電圧が出力端子（１
９）（２０）の出力信号のレベルに関わらず、常に一定
であり、信号源（１７）からの交流信号のレベルのみが
変化する。交流信号のレベルは、トランジスタ（２８）
のコレクタ電流の分流比で定まる。分流比は、差動増幅
器（２９）のトランジスタ（３０）（３１）に流れる電
流で変わる。出力端子（１９）の出力信号のレベルが高
く、トランジスタ（２８）のコレクタ電流が全てトラン
ジスタ（３１）に流れれば、利得は１となる。逆に出力
端子（１９）の出力信号のレベルが低く、トランジスタ
（２８）のコレクタ電流が全てトランジスタ（３０）に
流れれば、利得は０となる。Therefore, according to the circuit of FIG. 1, the level of the audio signal can be adjusted in a natural tone according to the analog control signal after D / A conversion. FIG. 5 shows a concrete circuit example of the GCA (16) of FIG. In FIG. 5, the same circuit elements as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. FIG.
In the circuit of, the DC voltage at the output terminal (3) is
9) It is always constant regardless of the level of the output signal of (20), and only the level of the AC signal from the signal source (17) changes. The level of the AC signal is transistor (28)
It is determined by the shunt ratio of the collector current of. The diversion ratio is changed by the current flowing through the transistors (30) (31) of the differential amplifier (29). If the level of the output signal of the output terminal (19) is high and the collector current of the transistor (28) all flows through the transistor (31), the gain becomes 1. On the contrary, if the level of the output signal of the output terminal (19) is low and all the collector current of the transistor (28) flows through the transistor (30), the gain becomes zero.
【００１５】従って、図５の回路によれば、出力端子
（１９）の出力信号のレベル低下により、ミュートがで
きる。Therefore, according to the circuit of FIG. 5, muting can be performed by lowering the level of the output signal of the output terminal (19).
【００１６】[0016]
【発明の効果】以上述べた如く、本発明によれば、制御
信号のレベルに応じて入力信号のレベルを調整できる電
子ボリューム回路が提供できる。特に、本発明によれ
ば、Ｄ/Ａ変換後のアナログ制御信号に応じて音声信号
を自然な調子でレベル調整できる電子ボリューム回路が
提供できる。As described above, according to the present invention, it is possible to provide an electronic volume circuit capable of adjusting the level of an input signal according to the level of a control signal. In particular, according to the present invention, it is possible to provide an electronic volume circuit capable of adjusting the level of an audio signal in a natural tone according to an analog control signal after D / A conversion.
【図１】本発明の電子ボリューム回路を示す回路図であ
る。FIG. 1 is a circuit diagram showing an electronic volume circuit of the present invention.
【図２】従来の電子ボリューム回路を示す回路図であ
る。FIG. 2 is a circuit diagram showing a conventional electronic volume circuit.
【図３】従来の特性説明をするための特性図である。FIG. 3 is a characteristic diagram for explaining conventional characteristics.
【図４】本発明の特性説明をするための特性図である。FIG. 4 is a characteristic diagram for explaining characteristics of the present invention.
【図５】本発明のＧＣＡ（１６）の具体回路例を示す回
路図である。FIG. 5 is a circuit diagram showing a specific circuit example of the GCA (16) of the present invention.
（７） 可変基準電圧源 （９） 抵抗 （１０） 電流発生回路 （１５） 差動増幅器 （１６） ＧＣＡ （１８） 切り替えトランジスタ (7) Variable reference voltage source (9) Resistor (10) Current generation circuit (15) Differential amplifier (16) GCA (18) Switching transistor
Claims (3)
圧が変化する可変基準電圧源と、 一端に前記可変基準電圧源の電圧が印加される抵抗と、 エミッタが前記抵抗の他端に接続されベースに定電圧が
印加されるトランジスタを含む電流発生回路と、 該電流発生回路の出力電流に応じて動作する差動増幅器
と、 該差動増幅器の出力信号に応じて入力信号のレベルを調
整するＧＣＡと、 前記可変基準電圧源の電圧が所定値になったことを検出
し、その検出出力信号に応じて前記差動増幅器の出力信
号の状態を強制的に切り換える切り替え制御回路とを備
えることを特徴とする電子ボリューム回路。1. A variable reference voltage source whose reference voltage changes according to the control amount of an electronic volume, a resistor to which the voltage of the variable reference voltage source is applied at one end, and an emitter connected to the other end of the resistor. A current generating circuit including a transistor to which a constant voltage is applied to the base, a differential amplifier that operates according to the output current of the current generating circuit, and the level of the input signal is adjusted according to the output signal of the differential amplifier. GCA, and a switching control circuit that detects that the voltage of the variable reference voltage source has reached a predetermined value and forcibly switches the state of the output signal of the differential amplifier according to the detected output signal. A characteristic electronic volume circuit.
圧が変化する可変基準電圧源と、 一端に前記可変基準電圧源の電圧が印加される抵抗と、 エミッタが前記抵抗の他端に接続されベースに定電圧が
印加される第１トランジスタを含む電流発生回路と、 該電流発生回路の出力電流に応じて動作する差動増幅器
と、 該差動増幅器の出力信号に応じて入力信号のレベルを調
整するＧＣＡと、 エミッタに前記可変基準電圧源の電圧が印加されベース
に基準電圧が印加されコレクタが前記差動増幅器の出力
側に接続された第２トランジスタを有し前記可変基準電
圧源の電圧が所定値になったことを検出し、その検出出
力信号に応じて前記差動増幅器の出力信号の状態を強制
的に切り換える切り替え制御回路とを備えることを特徴
とする電子ボリューム回路。2. A variable reference voltage source whose reference voltage changes according to the control amount of an electronic potentiometer, a resistor to which the voltage of the variable reference voltage source is applied at one end, and an emitter connected to the other end of the resistor. A current generation circuit including a first transistor to which a constant voltage is applied to the base, a differential amplifier that operates according to the output current of the current generation circuit, and a level of an input signal that depends on the output signal of the differential amplifier. A voltage of the variable reference voltage source having a GCA to be adjusted, a second transistor having an emitter to which the voltage of the variable reference voltage source is applied, a base to which the reference voltage is applied, and a collector connected to the output side of the differential amplifier. And a switching control circuit for forcibly switching the state of the output signal of the differential amplifier in accordance with the detected output signal. Beam circuit.
て基準電圧が変化する可変基準電圧源と、 一端に前記可変基準電圧源の電圧が印加される抵抗と、 エミッタが前記抵抗の他端に接続されベースに定電圧が
印加されるトランジスタを含む電流発生回路と、 該電流発生回路の出力電流に応じて動作する差動増幅器
と、 該差動増幅器の出力信号に応じて入力信号のレベルを調
整するＧＣＡと、 前記可変基準電圧源の電圧が所定値になったことを検出
し、その検出出力信号に応じて前記差動増幅器の出力信
号の状態を強制的に切り換える切り替え制御回路とを備
えることを特徴とする電子ボリューム回路。3. A variable reference voltage source whose reference voltage changes according to the analog control signal after D / A conversion, a resistor to which the voltage of the variable reference voltage source is applied at one end, and an emitter whose other A current generating circuit including a transistor connected to the end and having a constant voltage applied to the base, a differential amplifier that operates according to the output current of the current generating circuit, and an input signal that corresponds to the output signal of the differential amplifier. A GCA for adjusting the level, and a switching control circuit for detecting that the voltage of the variable reference voltage source has reached a predetermined value and forcibly switching the state of the output signal of the differential amplifier according to the detected output signal. An electronic volume circuit comprising:
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04368896A JP3253512B2 (en) | 1996-02-29 | 1996-02-29 | Electronic volume circuit |
| US08/805,291 US6317502B1 (en) | 1996-02-29 | 1997-02-25 | Electronic volume control circuit with controlled output characteristic |
| DE69725362T DE69725362T2 (en) | 1996-02-29 | 1997-02-27 | Electronic volume control circuit with controlled output characteristics |
| EP97103269A EP0793339B1 (en) | 1996-02-29 | 1997-02-27 | Electronic volume control circuit with controlled output characteristic |
| AT97103269T ATE251817T1 (en) | 1996-02-29 | 1997-02-27 | ELECTRONIC VOLUME CONTROL CIRCUIT WITH CONTROLLED OUTPUT CHARACTERISTICS |
| KR1019970006835A KR100235414B1 (en) | 1996-02-29 | 1997-02-28 | Electronic volume circuit with output characteristics adjusted |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04368896A JP3253512B2 (en) | 1996-02-29 | 1996-02-29 | Electronic volume circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09238036A true JPH09238036A (en) | 1997-09-09 |
| JP3253512B2 JP3253512B2 (en) | 2002-02-04 |
Family
ID=12670788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04368896A Expired - Fee Related JP3253512B2 (en) | 1996-02-29 | 1996-02-29 | Electronic volume circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3253512B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005051420A1 (en) | 2005-10-27 | 2007-05-03 | Robert Bosch Gmbh | Method and plant for dry conversion of a material structure of semi-finished products |
-
1996
- 1996-02-29 JP JP04368896A patent/JP3253512B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP3253512B2 (en) | 2002-02-04 |
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