JPS6286908A - Output voltage correcting circuit for amplifier - Google Patents

Output voltage correcting circuit for amplifier

Info

Publication number
JPS6286908A
JPS6286908A JP60226494A JP22649485A JPS6286908A JP S6286908 A JPS6286908 A JP S6286908A JP 60226494 A JP60226494 A JP 60226494A JP 22649485 A JP22649485 A JP 22649485A JP S6286908 A JPS6286908 A JP S6286908A
Authority
JP
Japan
Prior art keywords
amplifier
level
difference
negative
output signals
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
JP60226494A
Other languages
Japanese (ja)
Inventor
Toshihiro Yamanaka
俊宏 山中
Seiichiro Hirayama
平山 誠一郎
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.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP60226494A priority Critical patent/JPS6286908A/en
Publication of JPS6286908A publication Critical patent/JPS6286908A/en
Pending legal-status Critical Current

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  • Amplifiers (AREA)

Abstract

PURPOSE:To maintain DC level of output signals or level of low frequency at a specified value by calculating the difference between output signals of positive polarity and output signals of negative polarity and negative feeding back to an amplifier to make calculated difference zero. CONSTITUTION:A difference amplifier 1 consists of an amplifier A, resistors Rf1, Rf2 and a capacitor Cf, and a negative feedback circuit 2 consists of a transistor TR3. A differential amplifier 3 consists of transistors TR1, TR2, resistors Rc1, Rc2 and a constant current power source CC. By such constitution, the difference between output signals VOUT+ of positive polarity and output signals VOUT- of negative polarity is calculated using the difference amplifier 1, and DC bias voltage of the differential amplifier 3 is controlled through the negative feedback circuit 2 to make the difference zero. Thereby, DC level or low frequency level of output signals VOUT+ of positive polarity and output signals VOUT- of negative polarity can be negative feedback controlled to zero level. Accordingly, the capacity of the capacitor C used in the differential amplifier 1 can be made small.

Description

【発明の詳細な説明】 〔概要〕 増幅器から出力される正極性の信号および負極性の信号
の直流レベルを所定値に保持する出力電圧補正回路にお
いて、出力される正極性の信号と。
DETAILED DESCRIPTION OF THE INVENTION [Summary] In an output voltage correction circuit that maintains the DC level of a positive polarity signal and a negative polarity signal output from an amplifier at predetermined values, a positive polarity signal outputted from an amplifier.

負極性の信号との差分を算出する差分増幅器と。and a difference amplifier that calculates the difference with a negative polarity signal.

算出した差分を零にするよう増幅器に負帰還する負帰還
回路とを備え、出力信号の直流レベルを所定値に保持す
るように制御している。
It is equipped with a negative feedback circuit that provides negative feedback to the amplifier so as to reduce the calculated difference to zero, and controls the DC level of the output signal to be maintained at a predetermined value.

〔産業上の利用分野〕[Industrial application field]

本発明は、出力する正極性信号および負極性信号の差分
が零になるように増幅器に負帰還し、出力信号の直流レ
ベルを所定値に保持するよう構成した増幅器の出力電圧
補正回路に関するものである。
The present invention relates to an amplifier output voltage correction circuit configured to provide negative feedback to the amplifier so that the difference between the output positive polarity signal and the negative polarity signal becomes zero, and to maintain the DC level of the output signal at a predetermined value. be.

C従来の技術) 従来、出力信号として極性のみ異なる正極性信号および
負極性信号を出力する際に、直流電圧レベルないし低周
波数の電圧レベルを所定値例えは零レベルに保持する回
路として、第2図に示すような出力電圧補正回路がある
。この回路から出力される正極性信号V。u7.は9人
力信号Vl)lを増幅器A、を用いて増幅すると共に、
増幅器A3およびコンデンサCf1からなる積分回路を
、増幅器A1の出力端と入力端との間に図示のように接
続して直流レベルないし低周波数のレベルを補正するこ
とによって得られる。同様に、この回路から出力される
負極性信号■。ut−は、入力信号VINを増幅器A2
を用いて反転増幅すると共に、増幅器A4およびコンデ
ンサCtZからなる積分回路を増幅器A2の出力端と入
力端との間に図示のように接続して直流レベルないし低
周波数のレベルを補正することによって得られる。
C) Conventionally, when outputting a positive polarity signal and a negative polarity signal that differ only in polarity as output signals, a second There is an output voltage correction circuit as shown in the figure. Positive polarity signal V output from this circuit. u7. amplifies the human power signal Vl)l using an amplifier A, and
This is obtained by connecting an integrating circuit consisting of amplifier A3 and capacitor Cf1 between the output terminal and input terminal of amplifier A1 as shown in the figure to correct the DC level or low frequency level. Similarly, the negative polarity signal ■ output from this circuit. ut- connects the input signal VIN to amplifier A2
This can be obtained by inverting and amplifying using the amplifier A4 and by connecting an integrating circuit consisting of the amplifier A4 and the capacitor CtZ between the output terminal and the input terminal of the amplifier A2 as shown in the figure to correct the DC level or low frequency level. It will be done.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

従来、第2図に示すように、出力電圧の直流レベルない
し低周波数のレベルを所定レベル例えば零レベルに保持
するために、増幅器A、および反転増幅器A2の出力端
と入力端との間に、コンデンサCr1l  Crtを接
続した積分増幅器を接続していた。このように、積分増
幅器を用い出力電圧を直接に積分して出力電圧の直流レ
ベルないし低周波数のレベルを零レベルに保持するため
、大容量のコンデンサを使用しないと、低周波数の出力
信号に歪が生じてしまうという問題点があった。このた
め、どうしても大きな容量のコンデンサC21゜Cr2
を用いなければならないという問題点もあった。特に、
LSI化する際に、大きな容量のコンデンサを用いる回
路は、その性質上望ましいものではない。
Conventionally, as shown in FIG. 2, in order to maintain the DC level or low frequency level of the output voltage at a predetermined level, for example, zero level, between the output end and the input end of the amplifier A and the inverting amplifier A2, An integrating amplifier connected to a capacitor Cr1l Crt was connected. In this way, an integrating amplifier is used to directly integrate the output voltage and maintain the DC level or low frequency level of the output voltage at zero level, so unless a large capacitance capacitor is used, the low frequency output signal will be distorted. There was a problem in that this would occur. For this reason, it is necessary to use a capacitor C21°Cr2 with a large capacity.
There was also the problem that it had to be used. especially,
When integrated into an LSI, a circuit that uses a large capacitance capacitor is not desirable due to its nature.

〔問題点を解決するための手段〕[Means for solving problems]

本発明は、前記問題点を解決するために、正極性の出力
信号および負極性の出力信号の差分を算出し、この算出
した差分が零になるように増幅器に負帰還する構成を採
用することにより、出力信号の直流レベルないし低周波
数のレベルを所定値に保持するようにしている。
In order to solve the above problem, the present invention employs a configuration in which a difference between a positive polarity output signal and a negative polarity output signal is calculated, and negative feedback is provided to the amplifier so that the calculated difference becomes zero. Thus, the DC level or low frequency level of the output signal is maintained at a predetermined value.

第1図に示す本発明の1実施例構成を用いて問題点を解
決するための手段を説明する。
Means for solving the problems will be explained using the configuration of one embodiment of the present invention shown in FIG.

第1図において、差分増幅器1は、正極性の出力信号V
。ut+および負極性の出力信号V。UT−との差分を
算出するものである。
In FIG. 1, the differential amplifier 1 has a positive polarity output signal V
. ut+ and negative polarity output signal V. This is to calculate the difference from UT-.

負帰還回路2は、差分増幅器1によって算出された差分
を、差動増幅器3に負帰還し本増幅器に安定したバイア
ス電圧を供給するものである。
The negative feedback circuit 2 provides negative feedback of the difference calculated by the differential amplifier 1 to the differential amplifier 3, and supplies a stable bias voltage to this amplifier.

差動増幅器3は、入力信号VIN、およびVIN−を夫
々反転増幅するものである。
The differential amplifier 3 inverts and amplifies the input signals VIN and VIN-, respectively.

〔作用〕[Effect]

第1図を用いて説明した構成を採用し、差分増幅器1を
用いて正極性の出力信号V。tlToと負極性の出力信
号V。LIT−との差分を算出し、この算出した差分が
零となるように負帰還回路2を介して差動増幅器3を制
御している。このため、正極性の出力信号■。UT。お
よび負極性の出力信号V。UT−の直流レベルないし低
周波数のレベルが、夫々所定レベル例えば零レベルに保
持されることとなる。
The configuration explained using FIG. 1 is adopted, and a positive polarity output signal V is generated using a differential amplifier 1. tlTo and a negative polarity output signal V. The difference with LIT- is calculated, and the differential amplifier 3 is controlled via the negative feedback circuit 2 so that the calculated difference becomes zero. Therefore, the positive polarity output signal■. U.T. and negative polarity output signal V. The DC level or low frequency level of UT- is maintained at a predetermined level, for example, zero level.

〔実施例〕〔Example〕

第1図は本発明の1実施例構成を示す。図中。 FIG. 1 shows the configuration of one embodiment of the present invention. In the figure.

1は差分増幅器、2は負帰還回路、3は差動増幅器、4
−1.4−2はバッファ増幅器、TR,ないしT Ri
はトランジスタ、Cfはコンデンサ。
1 is a differential amplifier, 2 is a negative feedback circuit, 3 is a differential amplifier, 4
-1.4-2 is a buffer amplifier, TR or T Ri
is a transistor, and Cf is a capacitor.

Rr++  Rrz+  Rei Rctは抵抗、CC
は定電流電源を表す。
Rr++ Rrz+ Rei Rct is resistance, CC
represents a constant current power supply.

第1図において、差分増幅器1は、増幅器A。In FIG. 1, the differential amplifier 1 is an amplifier A.

抵抗Rfl+  RfZおよびコンデンサCfとから構
成されている。この増幅器Aの負極性端子と、正極性の
出力信号■。IJT。の端子および負極性の出力信号V
。。7−の端子との間に抵抗RflおよびRfZが夫々
接続されている。そして、増幅器Aの正極性端子が接地
されている。従って、当該抵抗Rf1およびRrtの値
を等しい値に設定すると、正極性の出力信号■。Uア、
と負極性の出力信号V。Ll、−との差分が算出される
。また、この増幅器Aの負極性端子と出力端との間にコ
ンデンサCfが接続されているため、いわゆる積分増幅
器として動作することとなる。
It is composed of resistors Rfl+RfZ and capacitor Cf. The negative polarity terminal of this amplifier A and the positive polarity output signal ■. I.J.T. terminal and negative polarity output signal V
. . Resistors Rfl and RfZ are connected between terminals 7- and 7-, respectively. The positive terminal of amplifier A is grounded. Therefore, if the values of the resistors Rf1 and Rrt are set to the same value, a positive polarity output signal (2) will be generated. Ua,
and negative polarity output signal V. The difference between Ll and - is calculated. Furthermore, since the capacitor Cf is connected between the negative terminal and the output terminal of this amplifier A, it operates as a so-called integrating amplifier.

負帰還回路2は、トランジスタTR3から構成されてい
る。このトランジスタT Rzのベース電位を制御する
ことにより、差動増幅器3に流れる電流の値を制御して
、出力信号の直流レベルないし低周波数のレベルを所定
値に保持させることができる。
Negative feedback circuit 2 is composed of transistor TR3. By controlling the base potential of this transistor T Rz, the value of the current flowing through the differential amplifier 3 can be controlled and the DC level or low frequency level of the output signal can be maintained at a predetermined value.

差動増幅器3は、トランジスタTR,、TR24抵抗R
ct、 Re2+ および定電流電源CCとから構成さ
れている。この差動増幅器3は、正極性の入力信号■、
。および負極性の入力信号VIN−を。
The differential amplifier 3 includes transistors TR, TR24 and resistor R.
ct, Re2+, and a constant current power supply CC. This differential amplifier 3 receives a positive polarity input signal ■,
. and negative polarity input signal VIN-.

夫々反転増幅して出力するものである。この出力された
各信号は、バッファ増幅器4−1.4−2によって夫々
増幅され、負極性の出力信号V。UT−および正極性の
出力信号■。LI?+とじて出力される。
Each signal is inverted and amplified and output. Each of the output signals is amplified by buffer amplifiers 4-1 and 4-2, respectively, to produce an output signal V of negative polarity. UT- and positive polarity output signal■. LI? It is output as +.

以上説明したような構成を採用し、差分増幅器1を用い
て、正極性の出力信号■。。ア、と、負極性の出力信号
V。LI?−との差分を算出し、この差分が零になるよ
うに、負帰還回路2を介して差動増幅器3の直流バイア
ス電圧を制御し、正極性の出力信号■。UT。および負
極性の出力信号■。tl?−の直流レベルないし低周波
数のレベルを零レベルに負帰還制御することができる。
By adopting the configuration as explained above and using the differential amplifier 1, a positive polarity output signal ■ is generated. . A, negative polarity output signal V. LI? - is calculated, and the DC bias voltage of the differential amplifier 3 is controlled via the negative feedback circuit 2 so that this difference becomes zero, and a positive output signal (■) is generated. U.T. and negative polarity output signal■. tl? − It is possible to perform negative feedback control of the DC level or the low frequency level to zero level.

このため、差分増幅器■に用いるコンデンサOfの容量
を小さくすることができる。換言すれば、第2図に示す
従来の回路は、出力信号を直接に積分したために大きな
容量のコンデンサを必要とした。これに比し1本発明は
、正極性信号と負極性信号との差分を算出し。
Therefore, the capacitance of the capacitor Of used in the differential amplifier (2) can be reduced. In other words, the conventional circuit shown in FIG. 2 requires a large capacitor because the output signal is directly integrated. In contrast, the present invention calculates the difference between a positive polarity signal and a negative polarity signal.

この差分電圧を雰にするように負帰還しているため2低
周波の交流成分は除去され、高周波交流成分を除去する
ような、小さなコンデンサC2を用いた積分増幅器でよ
いこととなる。
Since this differential voltage is negatively fed back to the atmosphere, two low-frequency AC components are removed, and an integrating amplifier using a small capacitor C2 that removes high-frequency AC components can be used.

〔発明の効果〕〔Effect of the invention〕

以上説明したように2本発明によれば、出力する正極性
信号および負極性信号の差分を算出し3この算出した差
分が雰になるように増幅器に負帰還する構成を採用して
いるため、小容量のコンデンサを用いて出力信号の直流
レベルないし低周波数のレベルを所定値に保持すること
ができる。このため、小容量のコンデンサを用いて直流
出力電圧の補正を行っても、低周波数の出力電圧に歪な
どの悪影響を与えることがない。
As explained above, according to the present invention, the difference between the positive polarity signal and the negative polarity signal to be output is calculated and negative feedback is provided to the amplifier so that the calculated difference becomes negative. A small capacitor can be used to maintain the DC level or low frequency level of the output signal at a predetermined value. Therefore, even when the DC output voltage is corrected using a small capacitance capacitor, there is no adverse effect such as distortion on the low frequency output voltage.

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

第1図は本発明の1実施例構成図、第2図は従来の増幅
器の出力電圧補正回路を示す。 図中、lは差分増幅器、2は負帰還回路、3は差動増幅
器、4−1.4−2はバッファ増幅器。 TR,ないしTR,はトランジスタ、Cfはコンデンサ
l  Rfll  Rf21  Rc++  Rcmは
抵抗、CCは定電流電源を表す。
FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 shows a conventional amplifier output voltage correction circuit. In the figure, l is a differential amplifier, 2 is a negative feedback circuit, 3 is a differential amplifier, and 4-1.4-2 is a buffer amplifier. TR or TR represents a transistor, Cf represents a capacitor l Rfll Rf21 Rc++ Rcm represents a resistor, and CC represents a constant current power supply.

Claims (1)

【特許請求の範囲】 増幅器から出力される正極性の信号および負極性の信号
の直流レベルを所定値に保持するよう制御を行う増幅器
の出力電圧補正回路において、増幅器から出力される正
極性の信号と、負極性の信号との差分を算出する差分増
幅器(1)と、この差分増幅器(1)を用いて算出した
差分を零にするよう増幅器に負帰還する負帰還回路(2
)とを備え、 増幅器から出力される正極性の信号および負極性の信号
の直流レベルを所定値に保持するよう制御を行うことを
特徴とする増幅器の出力電圧補正回路。
[Claims] In an amplifier output voltage correction circuit that controls the DC levels of a positive polarity signal and a negative polarity signal output from an amplifier to maintain them at predetermined values, a positive polarity signal output from the amplifier is provided. and a negative polarity signal, and a negative feedback circuit (2) that provides negative feedback to the amplifier so as to make the difference calculated using the difference amplifier (1) zero.
), and performs control to maintain the DC levels of a positive polarity signal and a negative polarity signal output from the amplifier at predetermined values.
JP60226494A 1985-10-11 1985-10-11 Output voltage correcting circuit for amplifier Pending JPS6286908A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60226494A JPS6286908A (en) 1985-10-11 1985-10-11 Output voltage correcting circuit for amplifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60226494A JPS6286908A (en) 1985-10-11 1985-10-11 Output voltage correcting circuit for amplifier

Publications (1)

Publication Number Publication Date
JPS6286908A true JPS6286908A (en) 1987-04-21

Family

ID=16845983

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60226494A Pending JPS6286908A (en) 1985-10-11 1985-10-11 Output voltage correcting circuit for amplifier

Country Status (1)

Country Link
JP (1) JPS6286908A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5386207A (en) * 1992-06-23 1995-01-31 Winbond Electronics North America Corporation Comparator with application in data communication
US6107867A (en) * 1994-09-30 2000-08-22 Lucent Technologies Inc. Load termination sensing circuit
JP2008245255A (en) * 2007-02-27 2008-10-09 Seiko Epson Corp Oscillation circuit and oscillator

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5379358A (en) * 1976-12-24 1978-07-13 Hitachi Ltd Multistage on-line differential amplifier
JPS5396650A (en) * 1977-02-02 1978-08-24 Nec Corp Automatic adjustment circuit for offset voltage
JPS5418215A (en) * 1977-07-12 1979-02-10 Toshiba Corp Balanced output amplifier
JPS56168410A (en) * 1980-05-28 1981-12-24 Toshiba Corp Differential amplifying circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5379358A (en) * 1976-12-24 1978-07-13 Hitachi Ltd Multistage on-line differential amplifier
JPS5396650A (en) * 1977-02-02 1978-08-24 Nec Corp Automatic adjustment circuit for offset voltage
JPS5418215A (en) * 1977-07-12 1979-02-10 Toshiba Corp Balanced output amplifier
JPS56168410A (en) * 1980-05-28 1981-12-24 Toshiba Corp Differential amplifying circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5386207A (en) * 1992-06-23 1995-01-31 Winbond Electronics North America Corporation Comparator with application in data communication
US6107867A (en) * 1994-09-30 2000-08-22 Lucent Technologies Inc. Load termination sensing circuit
JP2008245255A (en) * 2007-02-27 2008-10-09 Seiko Epson Corp Oscillation circuit and oscillator

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