JPH05110351A - Current voltage conversion circuit - Google Patents

Current voltage conversion circuit

Info

Publication number
JPH05110351A
JPH05110351A JP3294766A JP29476691A JPH05110351A JP H05110351 A JPH05110351 A JP H05110351A JP 3294766 A JP3294766 A JP 3294766A JP 29476691 A JP29476691 A JP 29476691A JP H05110351 A JPH05110351 A JP H05110351A
Authority
JP
Japan
Prior art keywords
amplifier
transistor
voltage
current feedback
output
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.)
Withdrawn
Application number
JP3294766A
Other languages
Japanese (ja)
Inventor
Masatoshi Homitsu
政敏 穂満
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.)
Olympus Corp
Original Assignee
Olympus Optical Co 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 Olympus Optical Co Ltd filed Critical Olympus Optical Co Ltd
Priority to JP3294766A priority Critical patent/JPH05110351A/en
Publication of JPH05110351A publication Critical patent/JPH05110351A/en
Withdrawn legal-status Critical Current

Links

Abstract

PURPOSE:To provide the current voltage conversion circuit in which the effect of a temperature characteristic of a base-emitter voltage of an amplifier transistor (TR) is eliminated and an output voltage at no input is set to an optional reference voltage. CONSTITUTION:One of two parallel current feedback amplifiers 11-1, 11-2 is used for a dummy amplifier, an output terminal of the dummy parallel current feedback amplifier 11-2 is connected to an inverting terminal of an operational amplifier 12, a control voltage V1 is applied to a noninverting terminal of the operational amplifier 12 and the output of the operational amplifier 12 is connected to a terminal 2 to which an emitter of an amplifier transistor (TR) of the two parallel current feedback amplifiers 11-1, 11-2 is connected and feedback is applied so that an output voltage of the parallel current feedback amplifier 11-1 is the control voltage V1.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】この発明は、撮像素子などの広帯
域(DC〜数十MHz)の光電流を電圧に変換する電流電
圧変換回路に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current-voltage conversion circuit for converting a broadband (DC to several tens of MHz) photocurrent of an image pickup device into a voltage.

【0002】[0002]

【従来の技術】従来、電流電圧変換回路としては種々の
構成のものが知られているが、図3にその構成例を示
す。図3において、Q21はベースを入力端子INとしエ
ミッタをGNDに接続した増幅用NPNトランジスタ
で、Q22は該増幅用トランジスタQ21にカスケードに接
続された高周波特性補償用のNPNトランジスタであ
り、R21は補償用トランジスタQ22のコレクタと電源V
CC間に接続された直流バイアス設定用の抵抗である。な
お補償用トランジスタQ22のベースには基準電圧VR
印加されている。補償用トランジスタQ22のコレクタに
ベースを接続したNPNトランジスタQ23のコレクタは
電源VCCに、エミッタはレベルシフト用ダイオードD21
のアノードに接続されている。ダイオードD21のカソー
ドには、一端をGNDに接続した出力段のバイアス電流
設定抵抗R23と、一端を増幅用トランジスタQ21のベー
スに接続した帰還抵抗R22を接続し、ダイオードD21の
カソードと各抵抗R22,R23の接続点を出力端子OUT
としている。
2. Description of the Related Art Conventionally, various configurations of current-voltage conversion circuits are known, and FIG. 3 shows an example of the configuration. In FIG. 3, Q21 is an amplifying NPN transistor whose base is an input terminal IN and whose emitter is connected to GND, Q22 is an NPN transistor for high frequency characteristic compensation connected in cascade to the amplifying transistor Q21, and R21 is a compensating device. Transistor Q22 collector and power supply V
This is a DC bias setting resistor connected between CC . The reference voltage V R is applied to the base of the compensation transistor Q22. The collector of an NPN transistor Q23, whose base is connected to the collector of the compensation transistor Q22, has its collector connected to the power supply V CC and its emitter a level shifting diode D21.
Connected to the anode of. To the cathode of the diode D21, a bias current setting resistor R23 of the output stage whose one end is connected to GND and a feedback resistor R22 whose one end is connected to the base of the amplifying transistor Q21 are connected, and the cathode of the diode D21 and each resistor R22, Output terminal OUT at the connection point of R23
I am trying.

【0003】このように構成された電流電圧変換回路に
おいて、増幅用トランジスタQ21のベースが接続されて
いる入力端子INから入力光電流iを入力すると、出力
端子OUTからは次式で示される出力電圧VOUT が出力
される。 VOUT =VBE(Q21)+i・R22 ここで、VBE(Q21)は増幅用トランジスタQ21のベー
ス・エミッタ間電圧、R22は帰還抵抗R22の抵抗値であ
る。
In the current-voltage conversion circuit thus configured, when the input photocurrent i is input from the input terminal IN to which the base of the amplifying transistor Q21 is connected, the output voltage from the output terminal OUT is expressed by the following equation. V OUT is output. V OUT = V BE (Q21) + i · R 22 Here, V BE (Q21) is the base-emitter voltage of the amplifying transistor Q21, and R 22 is the resistance value of the feedback resistor R22.

【0004】[0004]

【発明が解決しようとする課題】ところで、上記従来の
電流電圧変換回路においては、無入力時の出力電圧は、
BE(Q21)となるので、ΔVBE(Q21)/ΔTという
増幅用トランジスタの温度特性をもつことになり、また
その出力電圧は固定電圧になってしまうという問題点が
あった。
In the conventional current-voltage conversion circuit described above, the output voltage when there is no input is
Since V BE (Q21), the temperature characteristic of the amplifying transistor is ΔV BE (Q21) / ΔT, and the output voltage becomes a fixed voltage.

【0005】本発明は、従来の電流電圧変換回路におけ
る上記問題点を解消するためになされたもので、増幅用
トランジスタの温度特性の影響をなくすことができ、無
入力時の出力電圧を任意の基準電圧にすることの可能な
電流電圧変換回路を提供することを目的とする。
The present invention has been made in order to solve the above problems in the conventional current-voltage conversion circuit. It is possible to eliminate the influence of the temperature characteristics of the amplifying transistor and to set the output voltage at the time of no input to an arbitrary value. An object of the present invention is to provide a current-voltage conversion circuit that can be used as a reference voltage.

【0006】[0006]

【課題を解決するための手段及び作用】上記問題点を解
決するため、本発明は、第1のNPNトランジスタに第
2のNPNトランジスタをカスケードに接続し、第2の
トランジスタのコレクタに第1の抵抗と第3のNPNト
ランジスタのベースを接続し、第1の抵抗の他端と第3
のトランジスタのコレクタを第1の電源に接続し、第3
のトランジスタのエミッタにダイオードのアノードを接
続し、ダイオードのカソードに出力端子並びに第2及び
第3の抵抗を接続し、第2の抵抗の他端は第1のトラン
ジスタのベースに、第3の抵抗の他端は第2の電源に接
続してなる同じ構成の2つの並列電流帰還増幅器を用
い、第1の並列電流帰還増幅器の出力端子を第3の増幅
器の反転端子に、第3の増幅器の出力を第1及び第2の
並列電流帰還増幅器の第1のトランジスタのエミッタに
接続し、第3の増幅器の非反転端子に制御電圧を印加
し、第2の並列電流帰還増幅器の第1のトランジスタの
ベースを入力端とし、第2の並列電流帰還増幅器の出力
端子を出力端として電流電圧変換回路を構成するもので
ある。
In order to solve the above-mentioned problems, the present invention connects a first NPN transistor with a second NPN transistor in cascade, and a collector of the first transistor has a first NPN transistor. The resistor is connected to the base of the third NPN transistor, and the other end of the first resistor is connected to the third resistor.
Connect the collector of the transistor to the first power supply and
The emitter of the transistor is connected to the anode of the diode, the cathode of the diode is connected to the output terminal and the second and third resistors, and the other end of the second resistor is connected to the base of the first transistor and the third resistor. The other end of the two parallel current feedback amplifiers having the same structure connected to the second power source is used, and the output terminal of the first parallel current feedback amplifier is used as the inverting terminal of the third amplifier and the output terminal of the third amplifier is connected. The output is connected to the emitters of the first transistors of the first and second parallel current feedback amplifiers, a control voltage is applied to the non-inverting terminal of the third amplifier, and the first transistor of the second parallel current feedback amplifier is connected. Of the second parallel current feedback amplifier is used as an output end of the current-voltage conversion circuit.

【0007】このように構成した電流電圧変換回路にお
いては、ダミーとなる第1の並列電流帰還増幅器の出力
を第3の増幅器の反転端子に接続し、第3の増幅器の出
力をダミーとなる第1の並列電流帰還増幅器及び光電流
が入力される第2の並列電流帰還増幅器の初段の第1の
トランジスタのエミッタに接続しているので、第3の増
幅器の非反転端子に与えられる制御電圧と第2の並列電
流帰還増幅器の出力電圧が同じになるように作用する。
これにより無入力時の出力電圧を、第3の増幅器の非反
転端子に与えられる制御電圧により任意の基準電圧にす
ることが可能となる。また第1のトランジスタのベース
・エミッタ間電圧VBEの温度特性の影響を受けない回路
となる。
In the current-voltage conversion circuit thus constructed, the output of the dummy first parallel current feedback amplifier is connected to the inverting terminal of the third amplifier, and the output of the third amplifier becomes the dummy. Since it is connected to the emitter of the first transistor of the first stage of the first parallel current feedback amplifier and the second parallel current feedback amplifier to which the photocurrent is input, the control voltage applied to the non-inverting terminal of the third amplifier is It acts so that the output voltage of the second parallel current feedback amplifier is the same.
As a result, the output voltage when there is no input can be set to an arbitrary reference voltage by the control voltage applied to the non-inverting terminal of the third amplifier. Further, the circuit is not affected by the temperature characteristic of the base-emitter voltage V BE of the first transistor.

【0008】[0008]

【実施例】次に実施例について説明する。図1は、本発
明に係る電流電圧変換回路に用いる並列電流帰還増幅器
の構成例を示す回路構成図である。図において、Q11は
ベースを入力端子1に接続しエミッタを端子2に接続し
た初段の増幅用NPNトランジスタで、Q12は前記増幅
用トランジスタQ11の高周波特性を補償するために増幅
用トランジスタQ11にカスケードに接続されたNPNト
ランジスタであり、R11は補償用トランジスタQ12のコ
レクタと電源端子3との間に接続された初段のバイアス
電流を決める抵抗である。なお補償用トランジスタQ12
のベースには基準電圧VR が印加されている。補償用ト
ランジスタQ12のコレクタにベースを接続したNPNト
ランジスタQ13のコレクタは電源端子3に、エミッタは
レベルシフト用ダイオードD11のアノードに接続されて
いる。ダイオードD11のカソードには、一端をGND端
子4に接続した出力段のバイアス電流設定抵抗R13と、
一端を増幅用トランジスタQ11のベースに接続した帰還
抵抗R12を接続し、ダイオードD11のカソードとバイア
ス電流設定抵抗R13と帰還抵抗R12の接続点を出力端子
5に接続して並列電流帰還増幅器を構成している。
EXAMPLES Next, examples will be described. FIG. 1 is a circuit configuration diagram showing a configuration example of a parallel current feedback amplifier used in the current-voltage conversion circuit according to the present invention. In the figure, Q11 is a first-stage amplifying NPN transistor whose base is connected to the input terminal 1 and whose emitter is connected to the terminal 2. Q12 is cascaded to the amplifying transistor Q11 in order to compensate the high frequency characteristics of the amplifying transistor Q11. R11 is a resistor connected to the collector of the compensating transistor Q12 and the power supply terminal 3 for determining the bias current of the first stage. Note that the compensation transistor Q12
The reference voltage V R is applied to the base of the. The collector of an NPN transistor Q13, whose base is connected to the collector of the compensating transistor Q12, is connected to the power supply terminal 3, and its emitter is connected to the anode of the level shifting diode D11. At the cathode of the diode D11, a bias current setting resistor R13 of the output stage, one end of which is connected to the GND terminal 4,
A feedback resistor R12 whose one end is connected to the base of the amplifying transistor Q11 is connected, and the cathode of the diode D11 and the connection point of the bias current setting resistor R13 and the feedback resistor R12 are connected to the output terminal 5 to form a parallel current feedback amplifier. ing.

【0009】本発明は、このように構成した並列電流帰
還増幅器を、1個をダミーとして2個用い、これに第3
の演算増幅器を組み合わせて電流電圧変換回路を構成す
るものである。図2は、本発明に係る電流電圧変換回路
の実施例を示すブロック構成図であり、11-1と11-2は図
1に示したと同様な構成の並列電流帰還増幅器で、その
一方11-2はダミーとして用いられている。そしてダミー
用の並列電流帰還増幅器11-2の出力端子5を演算増幅器
12の反転端子に接続し、演算増幅器12の非反転端子には
制御電圧V1 が印加され、その出力は2つの並列電流帰
還増幅器11-1,11-2の増幅用トランジスタのエミッタが
接続されている端子2に接続されている。なおR1は演
算増幅器12の帰還抵抗であり、C1は演算増幅器12の出
力側に接続された高域特性補償用のコンデンサである。
According to the present invention, two parallel current feedback amplifiers configured as described above are used, one dummy and a third dummy current feedback amplifier.
A current-voltage conversion circuit is configured by combining the operational amplifiers of. FIG. 2 is a block diagram showing an embodiment of a current-voltage conversion circuit according to the present invention. 11-1 and 11-2 are parallel current feedback amplifiers having the same configuration as shown in FIG. 2 is used as a dummy. The output terminal 5 of the dummy parallel current feedback amplifier 11-2 is connected to the operational amplifier.
The control voltage V 1 is applied to the non-inverting terminal of the operational amplifier 12, and its output is connected to the emitters of the amplifying transistors of the two parallel current feedback amplifiers 11-1 and 11-2. Connected to the terminal 2. Note that R1 is a feedback resistor of the operational amplifier 12, and C1 is a capacitor for compensating for high frequency characteristics, which is connected to the output side of the operational amplifier 12.

【0010】このように構成された電流電圧変換回路に
おいては、並列電流帰還増幅器11-1の入力端子1より光
電流iが入力されると、その出力端子5より出力電圧V
OUT =V1 +i・R12が出力されるが、無入力時には並
列電流帰還増幅器11-1の出力端子5には、その出力電圧
が演算増幅器12の非反転端子に印加されている制御電圧
1 になるように帰還がかかることになる。したがって
無入力時の出力電圧は、演算増幅器12の非反転端子に印
加する制御電圧V1 を変更することにより、任意に設定
することができる。また補償用トランジスタのベース・
エミッタ間電圧VBE(Q11)の温度特性の影響を受けな
い電流電圧変換回路となる。
In the current-voltage conversion circuit thus configured, when the photocurrent i is input from the input terminal 1 of the parallel current feedback amplifier 11-1, the output voltage V is output from the output terminal 5 thereof.
OUT = V 1 + iR 12 is output, but when there is no input, the output voltage is applied to the output terminal 5 of the parallel current feedback amplifier 11-1 by the control voltage V applied to the non-inverting terminal of the operational amplifier 12. It will return to be 1 can take. Therefore, the output voltage when there is no input can be arbitrarily set by changing the control voltage V 1 applied to the non-inverting terminal of the operational amplifier 12. Also, the base of the compensation transistor
The current-voltage conversion circuit is not affected by the temperature characteristics of the emitter-to-emitter voltage V BE (Q11).

【0011】[0011]

【発明の効果】以上実施例に基づいて説明したように、
本発明によれば、増幅用トランジスタのベース・エミッ
タ間電圧の温度特性の影響をなくすことができ、また無
入力時の出力電圧を任意の基準電圧に設定することがで
きる。
As described above on the basis of the embodiments,
According to the present invention, the influence of the temperature characteristic of the base-emitter voltage of the amplifying transistor can be eliminated, and the output voltage when there is no input can be set to an arbitrary reference voltage.

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

【図1】本発明に係る電流電圧変換回路に用いる並列電
流帰還増幅器の構成例を示す回路構成図である。
FIG. 1 is a circuit configuration diagram showing a configuration example of a parallel current feedback amplifier used in a current-voltage conversion circuit according to the present invention.

【図2】本発明の一実施例を示すブロック構成図であ
る。
FIG. 2 is a block diagram showing an embodiment of the present invention.

【図3】従来の電流電圧変換回路の構成例を示す回路構
成図である。
FIG. 3 is a circuit configuration diagram showing a configuration example of a conventional current-voltage conversion circuit.

【符号の説明】[Explanation of symbols]

11-1 並列電流帰還増幅器 11-2 ダミー用の並列電流帰還増幅器 12 演算増幅器 11-1 Parallel current feedback amplifier 11-2 Parallel current feedback amplifier for dummy 12 Operational amplifier

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 第1のNPNトランジスタに第2のNP
Nトランジスタをカスケードに接続し、第2のトランジ
スタのコレクタに第1の抵抗と第3のNPNトランジス
タのベースを接続し、第1の抵抗の他端と第3のトラン
ジスタのコレクタを第1の電源に接続し、第3のトラン
ジスタのエミッタにダイオードのアノードを接続し、ダ
イオードのカソードに出力端子並びに第2及び第3の抵
抗を接続し、第2の抵抗の他端は第1のトランジスタの
ベースに、第3の抵抗の他端は第2の電源に接続してな
る同じ構成の2つの並列電流帰還増幅器を用い、第1の
並列電流帰還増幅器の出力端子を第3の増幅器の反転端
子に、第3の増幅器の出力を第1及び第2の並列電流帰
還増幅器の第1のトランジスタのエミッタに接続し、第
3の増幅器の非反転端子に制御電圧を印加し、第2の並
列電流帰還増幅器の第1のトランジスタのベースを入力
端とし、第2の並列電流帰還増幅器の出力端子を出力端
としたことを特徴とする電流電圧変換回路。
1. A second NP for the first NPN transistor.
The N-transistor is connected in cascade, the collector of the second transistor is connected to the first resistor and the base of the third NPN transistor, and the other end of the first resistor and the collector of the third transistor are connected to the first power supply. The anode of the diode is connected to the emitter of the third transistor, the output terminal and the second and third resistors are connected to the cathode of the diode, and the other end of the second resistor is the base of the first transistor. The other end of the third resistor is connected to the second power source, and two parallel current feedback amplifiers having the same configuration are used. The output terminal of the first parallel current feedback amplifier is used as the inverting terminal of the third amplifier. , The output of the third amplifier is connected to the emitters of the first transistors of the first and second parallel current feedback amplifiers, the control voltage is applied to the non-inverting terminal of the third amplifier, and the second parallel current feedback amplifier The base of the first transistor and the input terminal, the current-voltage conversion circuit, characterized in that the output terminal of the second parallel current feedback amplifier and the output terminal.
JP3294766A 1991-10-16 1991-10-16 Current voltage conversion circuit Withdrawn JPH05110351A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3294766A JPH05110351A (en) 1991-10-16 1991-10-16 Current voltage conversion circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3294766A JPH05110351A (en) 1991-10-16 1991-10-16 Current voltage conversion circuit

Publications (1)

Publication Number Publication Date
JPH05110351A true JPH05110351A (en) 1993-04-30

Family

ID=17812025

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3294766A Withdrawn JPH05110351A (en) 1991-10-16 1991-10-16 Current voltage conversion circuit

Country Status (1)

Country Link
JP (1) JPH05110351A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11174128A (en) * 1997-12-09 1999-07-02 Hitachi Electron Eng Co Ltd Load-current output circuit to electronic device and ic tester
JPH11174127A (en) * 1997-12-09 1999-07-02 Hitachi Electron Eng Co Ltd Load-current output circuit to electronic device and ic tester

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11174128A (en) * 1997-12-09 1999-07-02 Hitachi Electron Eng Co Ltd Load-current output circuit to electronic device and ic tester
JPH11174127A (en) * 1997-12-09 1999-07-02 Hitachi Electron Eng Co Ltd Load-current output circuit to electronic device and ic tester

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Legal Events

Date Code Title Description
A300 Withdrawal of application because of no request for examination

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 19990107