JPH0645263Y2 - Current-current conversion circuit - Google Patents
Current-current conversion circuitInfo
- Publication number
- JPH0645263Y2 JPH0645263Y2 JP1985118444U JP11844485U JPH0645263Y2 JP H0645263 Y2 JPH0645263 Y2 JP H0645263Y2 JP 1985118444 U JP1985118444 U JP 1985118444U JP 11844485 U JP11844485 U JP 11844485U JP H0645263 Y2 JPH0645263 Y2 JP H0645263Y2
- Authority
- JP
- Japan
- Prior art keywords
- current
- voltage
- output
- operational amplifier
- inverting
- 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.)
- Expired - Lifetime
Links
Landscapes
- Measurement Of Current Or Voltage (AREA)
- Testing Of Individual Semiconductor Devices (AREA)
Description
【考案の詳細な説明】 「産業上の利用分野」 この考案は電流を入力し、この電流と対応した大きさを
異にした電流を出力し、又は入力インピーダンスと出力
インピーダンスとを異ならせるために用いられる電流−
電流変換回路に関する。[Detailed Description of the Invention] “Industrial Application Field” This invention is for inputting a current and outputting a current having a magnitude different from this current, or for making an input impedance and an output impedance different. Current used-
The present invention relates to a current conversion circuit.
「従来の技術」 従来において電流を入力して、これと対応した電圧を出
力する電流−電圧変換回路や、逆に電圧を入力して、こ
れと対応した電流を出力する電圧−電流変換回路は用い
られていた。しかし電流を入力して、これと対応した異
なる電流を出力する電流−電流変換回路は知られていな
い。"Prior Art" Conventionally, a current-voltage conversion circuit that inputs a current and outputs a voltage corresponding to it, or a voltage-current conversion circuit that inputs a voltage and outputs a current corresponding to this, on the contrary, Was used. However, a current-current conversion circuit that inputs a current and outputs a different current corresponding to this is not known.
しかしこのような電流−電流変換回路が在れば例えば微
弱な電流の測定に頗る便利である。すなわち、第２図に
示すように測定ユニット11の電圧−電流印加用端子12,1
3はそれぞれ電圧−電流印加用導線14,15を通じて被測定
物16の両端に接続され、かつ電圧検出用端子17,18はそ
れぞれ電圧検出用導線21,22を通じて被測定物16の両端
に接続される。測定ユニット11内においてDA変換器23か
ら設定した電圧Vsを発生し、その電圧Vsは抵抗器24を通
じて演算増幅器25の反転入力側へ供給される。演算増幅
器25の非反転入力側は電圧検出用端子18に接続され、出
力側は電流検出用抵抗器26を通じて電圧−電流印加用端
子12に接続される。電圧検出用端子17はバッファ回路27
を通じ、更に抵抗器28を通じて演算増幅器25の反転入力
側に接続される。However, if such a current-current conversion circuit exists, it is very convenient to measure a weak current, for example. That is, as shown in FIG. 2, the voltage-current applying terminals 12, 1 of the measuring unit 11 are
3 is connected to both ends of the DUT 16 through the voltage-current applying leads 14 and 15, respectively, and the voltage detection terminals 17 and 18 are connected to both ends of the DUT 16 through the voltage detecting leads 21 and 22, respectively. It A voltage Vs set by the DA converter 23 is generated in the measuring unit 11, and the voltage Vs is supplied to the inverting input side of the operational amplifier 25 through the resistor 24. The non-inverting input side of the operational amplifier 25 is connected to the voltage detecting terminal 18, and the output side is connected to the voltage-current applying terminal 12 through the current detecting resistor 26. The voltage detection terminal 17 is a buffer circuit 27
Through the resistor 28 and the inverting input side of the operational amplifier 25.
被測定物16の一端の電圧がバッファ回路27を介して演算
増幅器25に帰還され、被測定物16の両端間に設定電圧Vs
が印加される。この電圧印加により被測定物16に流れる
電流IMは電流検出用抵抗器26を通り、その電流検出用抵
抗器26の両端電圧が電流検出回路29で検出され、その検
出電圧がAD変換器31でディジタル値に変換されて、被測
定物16に流れた電流が測定される。The voltage at one end of the DUT 16 is fed back to the operational amplifier 25 via the buffer circuit 27, and the set voltage Vs is applied across the DUT 16.
Is applied. The current I M flowing through the DUT 16 due to this voltage application passes through the current detection resistor 26, the voltage across the current detection resistor 26 is detected by the current detection circuit 29, and the detected voltage is the AD converter 31. Is converted into a digital value and the current flowing through the DUT 16 is measured.
被測定物16を流れる電流が例えば1nAのように微弱な上
に、測定ユニット11及び被測定物16間の距離が例えば10
mのように長い場合は、導線14の対地容量が比較的大き
くなり、高速度に高精度の測定を行うことは困難とな
る、また導線14の絶縁を十分保持することも難しく、雑
音の影響も受け易いなどの問題が生じる。The current flowing through the DUT 16 is weak such as 1 nA, and the distance between the measurement unit 11 and the DUT 16 is, for example, 10
When the length is long, such as m, the ground capacitance of the conductor 14 becomes relatively large, making it difficult to perform high-precision measurement at high speed.It is also difficult to maintain sufficient insulation of the conductor 14 and the influence of noise. It also causes problems such as being easily received.
しかし、点線で示すように導線14,21と被測定物16との
間に電流−電流変換回路32を挿入し、導線14を流れる電
流が、被測定物16を流れる電流より大きくなるように電
流変換すれば、前述した問題が解消される。However, as shown by the dotted line, the current-current conversion circuit 32 is inserted between the conductors 14 and 21 and the DUT 16, and the current flowing through the conductor 14 becomes larger than the current flowing through the DUT 16. If converted, the above-mentioned problem is solved.
「問題点を解決するための手段」 この考案によれば測定ユニットに電圧−電流印加用導線
を介して接続された入力端子は演算増幅器の非反転入力
側に接続され、その演算増幅器の反転入力側は出力端子
に接続され、出力側は電流−電圧変換用抵抗器を通じて
出力端子に接続される。また演算増幅器の出力側は反転
増幅器の反転入力側に接続され、反転増幅器の非反転入
力側は出力端子に接続され、出力側は電圧−電流変換用
抵抗器を通じて入力端子に接続される。この構成により
演算増幅器は印加される入力電圧に等しい出力電圧を発
生するから、入力端子に供給される電流と対応し、これ
と異なる電流が出力端子に得られる。According to the present invention, the input terminal connected to the measuring unit via the voltage-current applying conductor is connected to the non-inverting input side of the operational amplifier, and the inverting input of the operational amplifier is provided. The output side is connected to the output terminal, and the output side is connected to the output terminal through the current-voltage conversion resistor. The output side of the operational amplifier is connected to the inverting input side of the inverting amplifier, the non-inverting input side of the inverting amplifier is connected to the output terminal, and the output side is connected to the input terminal through the voltage-current conversion resistor. With this configuration, the operational amplifier produces an output voltage equal to the applied input voltage, so that a current corresponding to and different from the current supplied to the input terminal is obtained at the output terminal.
「実施例」 第１図はこの考案による電流−電流変換回路の実施例を
示す。入力端子41は演算増幅器42の非反転入力側に接続
され、演算増幅器42の反転入力側は出力端子43に接続さ
れ、出力側は電流−電圧変換用抵抗器44を通じて出力端
子43に接続される。演算増幅器42の出力側は反転増幅器
45の反転入力側にも接続され、また、出力端子43は反転
増幅器45の非反転入力側にも接続される。反転増幅器45
の出力側は電圧−電流変換用抵抗器46を通じて入力端子
41に接続される。反転増幅器45は、本例では、演算増幅
器47とこの演算増幅器47の出力側と反転入力側間に接続
された抵抗器49と反転入力側に直列に接続された抵抗器
48とから構成されており、上記演算増幅器42の出力側は
この抵抗器48を介して演算増幅器47の反転入力側に接続
され、出力端子43は演算増幅器47の非反転入力側に直接
接続されている。[Embodiment] FIG. 1 shows an embodiment of a current-current conversion circuit according to the present invention. The input terminal 41 is connected to the non-inverting input side of the operational amplifier 42, the inverting input side of the operational amplifier 42 is connected to the output terminal 43, and the output side is connected to the output terminal 43 through the current-voltage conversion resistor 44. . The output side of the operational amplifier 42 is an inverting amplifier
The output terminal 43 is also connected to the non-inverting input side of the inverting amplifier 45. Inverting amplifier 45
The output side of the input terminal through the voltage-current conversion resistor 46
Connected to 41. In this example, the inverting amplifier 45 includes an operational amplifier 47, a resistor 49 connected between the output side and the inverting input side of the operational amplifier 47, and a resistor connected in series to the inverting input side.
The output side of the operational amplifier 42 is connected to the inverting input side of the operational amplifier 47 through the resistor 48, and the output terminal 43 is directly connected to the non-inverting input side of the operational amplifier 47. ing.
入力端子41の電圧をVi、電流をIi、出力端子43の電圧を
Vo、電流をIo、抵抗器44,46,48,49の各抵抗値をそれぞ
れR1,R2,R3,R4とすると、入力端子41に定電圧Viを印加
すると、演算増幅器42の反転入力側に出力端子43の出力
電圧Voが帰還され、演算増幅器42はその両入力側の入力
の差がゼロになるように作用するため、出力端子43の出
力電圧Voは、 Vo＝Vi ……（１） となる。また電流−電圧変換用抵抗器44における降下電
圧IoR1が、出力端子43を基準として反転増幅器45で増幅
され、反転増幅器45の利得はR4/R3であり、かつ反転増
幅器45の出力側の電圧は演算増幅器42の非反転入力側、
つまり出力端子43に対し、抵抗器46の降下電圧IiR2だけ
低下しているから次式が成立つ。Input terminal 41 voltage is V i , current is I i , output terminal 43 voltage is
V o, current I o, when the resistance of the resistor 44,46,48,49 of the R 1, R 2, R 3 , R 4 , respectively, by applying a constant voltage V i to the input terminal 41, calculation The output voltage V o of the output terminal 43 is fed back to the inverting input side of the amplifier 42, and the operational amplifier 42 acts so that the difference between the inputs on both the input sides becomes zero. Therefore, the output voltage V o of the output terminal 43 is , V o = V i (1) Further, the voltage drop I o R 1 in the current-voltage conversion resistor 44 is amplified by the inverting amplifier 45 with the output terminal 43 as a reference, the gain of the inverting amplifier 45 is R 4 / R 3 , and the inverting amplifier 45 The voltage on the output side is the non-inverting input side of the operational amplifier 42,
That is, since the voltage drop I i R 2 of the resistor 46 is lower than the output terminal 43, the following equation is established.
また、入力端子41に定電流Iiを供給すると、同様にして Vi＝Vo＝IoRL ……（４） が成立つ。RLは被測定物16の抵抗値である。これらから
入力電流Iiと出力電流Ioとの比ｎは、 となる。従ってこれら抵抗値R1〜R4を適当に選ぶことに
より任意の入出力電流比ｎが得られる。この電流比ｎを
変化する場合、演算増幅器42の出力側は低インピーダン
スであるから抵抗値R1を変化させることが好ましい。な
お出力電流Ioを微小電流にする場合は演算増幅器42,47
の各入力インピーダンスを十分高くすることが好まし
く、出力電流Ioを大電流にする場合は演算増幅器42は電
流供給能力が大であることが望ましい。 In addition, if a constant current I i is supplied to the input terminal 41, V i = V o = I o R L (4) holds. R L is the resistance value of the DUT 16. From these, the ratio n of the input current I i and the output current I o is Becomes Therefore, an arbitrary input / output current ratio n can be obtained by appropriately selecting these resistance values R 1 to R 4 . When changing the current ratio n, it is preferable to change the resistance value R 1 because the output side of the operational amplifier 42 has low impedance. When the output current I o is set to a very small current, operational amplifiers 42 and 47
It is preferable that the input impedances of the above are sufficiently high, and if the output current I o is a large current, it is desirable that the operational amplifier 42 has a large current supply capability.
（１）式，（２）式また（３）式，（４）式から理解さ
れるように、この考案の電流−電流変換回路は入力電圧
Viと出力電圧Voとは等しいが、入力電流Iiと出力電流Io
とが異なっているから、入力インピーダンスと出力イン
ピーダンスとが異なったものとなり、この電流−電流変
換回路はインピーダンス変換回路としても動作する。As understood from the equations (1), (2) and (3), (4), the current-current conversion circuit of the present invention has an input voltage of
Although V i and output voltage V o are equal, input current I i and output current I o
Since the input impedance and the output impedance are different from each other, the current-current conversion circuit also operates as an impedance conversion circuit.
「考案の効果」 以上述べたようにこの考案によれば演算増幅器から発生
される出力電圧は印加される入力電圧に等しくなるか
ら、この演算増幅器に印加される入力電流に対して、そ
の出力電流は電流−電圧変換用抵抗器と電圧−電流変換
用抵抗器との抵抗比のみで正確に決まる電流となる。よ
って、任意の電流比の出力電流が得られるから、例えば
電流比を大きくすることによって被測定物に流れる微弱
な電流でも高い精度でかつ高速で測定することができる
という顕著な効果があり、各種の被測定物の電流測定に
適用してすこぶる好便である。またこの考案の回路はイ
ンピーダンス変換回路としても用いることができる。[Advantage of Device] As described above, according to this device, the output voltage generated from the operational amplifier becomes equal to the applied input voltage. Therefore, the output current is different from the input current applied to the operational amplifier. Is a current that is accurately determined only by the resistance ratio between the current-voltage conversion resistor and the voltage-current conversion resistor. Therefore, since an output current having an arbitrary current ratio can be obtained, there is a remarkable effect that even a weak current flowing in the object to be measured can be measured with high accuracy and high speed by increasing the current ratio, for example. It is very convenient to apply to current measurement of the measured object. The circuit of this invention can also be used as an impedance conversion circuit.
第１図はこの考案による電流−電流変換回路の一例を示
す接続図、第２図は電流−電流変換回路の適用例として
電圧印加電流測定器を示す図である。 41:入力端子、42:演算増幅器、43:出力端子、44:電流−
電圧変換用抵抗器、45:反転増幅器、46:電圧−電流変換
用抵抗器。FIG. 1 is a connection diagram showing an example of a current-current conversion circuit according to the present invention, and FIG. 2 is a diagram showing a voltage applied current measuring device as an application example of the current-current conversion circuit. 41: input terminal, 42: operational amplifier, 43: output terminal, 44: current −
Voltage conversion resistor, 45: inverting amplifier, 46: voltage-current conversion resistor.
Claims (1)
して接続された入力端子と、 被測定物に接続された出力端子と、 非反転入力側が前記入力端子に接続され、かつ反転入力
側が前記出力端子に接続された演算増幅器と、 該演算増幅器の出力側と前記出力端子間に接続された電
流−電圧変換用抵抗器と、 非反転側が前記出力端子に接続され、かつ反転入力側が
前記演算増幅器の出力側に接続された反転増幅器と、 該反転増幅器の出力側と前記入力端子間に接続された電
圧−電流変換用抵抗器とを具備し、 前記測定ユニットから前記入力端子を介して前記演算増
幅器の入力側に印加される入力電圧とその出力側から生
じる出力電圧とを同電圧にし、前記演算増幅器の入力側
に印加される電流とその出力側からの電流との比が、前
記電流−電圧変換用抵抗器と前記電圧−電流変換用抵抗
器との抵抗比と前記反転増幅器の利得との積のみで決ま
るようにしたことを特徴とする電流−電流変換回路。1. An input terminal connected to a measuring unit via a voltage-current applying conductor, an output terminal connected to a DUT, a non-inverting input side connected to the input terminal, and an inverting input side connected to the input terminal. An operational amplifier connected to the output terminal, a current-voltage conversion resistor connected between the output side of the operational amplifier and the output terminal, a non-inverting side connected to the output terminal, and an inverting input side connected to the output terminal. An inverting amplifier connected to the output side of the operational amplifier, and a voltage-current conversion resistor connected between the output side of the inverting amplifier and the input terminal, and from the measurement unit via the input terminal. The input voltage applied to the input side of the operational amplifier and the output voltage generated from the output side thereof are set to the same voltage, and the ratio of the current applied to the input side of the operational amplifier and the current from the output side thereof is Current − Current, characterized in that as determined only by the product of the resistance ratio of the current conversion resistor and the gain of the inverting amplifier - - the voltage and pressure transducer resistor current converter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985118444U JPH0645263Y2 (en) | 1985-07-31 | 1985-07-31 | Current-current conversion circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1985118444U JPH0645263Y2 (en) | 1985-07-31 | 1985-07-31 | Current-current conversion circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6267273U JPS6267273U (en) | 1987-04-27 |
| JPH0645263Y2 true JPH0645263Y2 (en) | 1994-11-16 |
Family
ID=31004900
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1985118444U Expired - Lifetime JPH0645263Y2 (en) | 1985-07-31 | 1985-07-31 | Current-current conversion circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0645263Y2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5718112A (en) * | 1980-07-08 | 1982-01-29 | Sony Corp | Current amplifier |
| JPS6329290Y2 (en) * | 1980-11-27 | 1988-08-08 |
-
1985
- 1985-07-31 JP JP1985118444U patent/JPH0645263Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6267273U (en) | 1987-04-27 |
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