JPH0854424A - Current application voltage measuring instrument - Google Patents
Current application voltage measuring instrumentInfo
- Publication number
- JPH0854424A JPH0854424A JP6210508A JP21050894A JPH0854424A JP H0854424 A JPH0854424 A JP H0854424A JP 6210508 A JP6210508 A JP 6210508A JP 21050894 A JP21050894 A JP 21050894A JP H0854424 A JPH0854424 A JP H0854424A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- voltage
- current
- logarithmic amplifier
- diode
- 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
Links
Landscapes
- Testing Of Individual Semiconductor Devices (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ＩＣ等の被試験デバイ
スの直流特性を測定する電圧印加電流測定装置に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage applied current measuring device for measuring the DC characteristics of a device under test such as an IC.
【０００２】[0002]
【従来の技術】図３に従来の電圧印加電流測定機能を持
つ回路の構造を示す。図中１は演算増幅器、２は被試験
デバイス、ＥＣはこの被試験デバイス２の端子２Ａ及び
２Ｂ間に所望の電圧を印加する直流電圧源、３は被試験
デバイス２に所定の電圧を与えたとき流れる電流を検出
する電流検出用抵抗器、４は被試験デバイス２の端子２
Ａに与えた電圧Ｖ0 を演算増幅器１の反転入力端子に負
帰還し、直流電圧源ＥＣから与えた電圧Ｅ0 と被試験デ
バイス２の端子２Ａ及び２Ｂ間に与える電圧Ｖ0を平衡
させて、端子２Ａ及び２Ｂ間に直流電圧源ＥＣから与え
た電圧Ｅ0 を正確に伝えるための電圧帰還回路、５は電
流検出用抵抗器３に発生する電圧を測定して被試験デバ
イス２に流れる電流値を求める電流測定回路、７は電流
検出用抵抗器３の電流検出特性に対数特性を持たせるダ
イオード逆並列回路をそれぞれ示す。2. Description of the Related Art FIG. 3 shows the structure of a circuit having a conventional voltage applied current measuring function. In the figure, 1 is an operational amplifier, 2 is a device under test, EC is a DC voltage source for applying a desired voltage between terminals 2A and 2B of the device under test 2, and 3 is a predetermined voltage applied to the device under test 2. A current detection resistor for detecting the current that flows when 4 is a terminal 2 of the device under test 2.
The voltage V 0 applied to A is negatively fed back to the inverting input terminal of the operational amplifier 1 to balance the voltage E 0 applied from the DC voltage source EC with the voltage V 0 applied between the terminals 2A and 2B of the device under test 2. , A voltage feedback circuit for accurately transmitting the voltage E 0 given from the DC voltage source EC between the terminals 2A and 2B, 5 is a current flowing through the device under test 2 by measuring the voltage generated in the current detecting resistor 3. Reference numeral 7 denotes a current measuring circuit for obtaining a value, and reference numeral 7 denotes a diode anti-parallel circuit for giving a logarithmic characteristic to the current detecting characteristic of the current detecting resistor 3.
【０００３】従来の回路構造で用いるレンジ切替回路６
は、演算増幅器６Ａと、この演算増幅器６Ａに引き算回
路５Ａから電流検出用抵抗器３を流れる電流と等価な電
流ＩL′ を与える入力抵抗器６Ｂと、この入力抵抗器６
Ｂに発生する電圧に対数特性を与えるダイオード逆並列
回路６Ｃと、演算増幅器６Ａの負帰還回路に接続した抵
抗切替回路６Ｄとによって構成される。ここで入力抵抗
器６Ｂの抵抗値Ｒ1′ と電流検出用抵抗器３の抵抗値Ｒ
1 とをＲ1′ ＝Ｒ1 に選定することによって、入力抵抗
器６Ｂを流れる電流ＩL′ は電流検出用抵抗器３を流れ
る電流ＩL に対してＩL′ ＝ＩL となる。この結果演算
増幅器６Ａに電流検出用抵抗器３で発生する電圧Ｖｘと
等価な電圧Ｖｘ′を与えることができ、この状態で抵抗
切替回路６Ｄの抵抗値を切り替えることによって演算増
幅器６Ａの利得が切り替えられ、ＡＤ変換器５Ｂに与え
る電圧信号のレベルを切り替えることができ、電流測定
レンジを切り替えることができる。Range switching circuit 6 used in the conventional circuit structure
Is an operational amplifier 6A, an input resistor 6B that gives the operational amplifier 6A a current I L ′ equivalent to the current flowing through the current detection resistor 3 from the subtraction circuit 5A, and the input resistor 6B.
It is composed of a diode anti-parallel circuit 6C that gives a logarithmic characteristic to the voltage generated in B, and a resistance switching circuit 6D connected to the negative feedback circuit of the operational amplifier 6A. Here, the resistance value R 1 ′ of the input resistor 6B and the resistance value R of the current detection resistor 3 are
By selecting 1 and R 1 ′ = R 1 , the current I L ′ flowing through the input resistor 6B becomes I L ′ = I L with respect to the current I L flowing through the current detecting resistor 3. As a result, a voltage Vx 'equivalent to the voltage Vx generated in the current detection resistor 3 can be applied to the operational amplifier 6A, and the gain of the operational amplifier 6A is switched by switching the resistance value of the resistance switching circuit 6D in this state. Therefore, the level of the voltage signal applied to the AD converter 5B can be switched, and the current measurement range can be switched.
【０００４】[0004]
【発明が解決しようとする課題】以上説明した従来の回
路構造においては、電流レンジ切り替え回路により、最
適レンジを選択しなければならない。このため、負荷電
流ＩL の大まかな電流値が予測できない場合は、あるレ
ンジで測定後、最適レンジを選択し、再度測定しなけれ
ばならない。その結果、測定時間が長くなるという問題
点があった。また、レンジ切り替えにはリレーを使用す
る事が多く、小型化の障害となっていた。本発明は、レ
ンジ切り替え回路を無くし、高速化、小型化した電圧印
加電流測定装置を実現することを目的とする。In the conventional circuit structure described above, the optimum range must be selected by the current range switching circuit. Therefore, when the rough current value of the load current I L cannot be predicted, the optimum range must be selected and measured again after the measurement in a certain range. As a result, there is a problem that the measurement time becomes long. Also, relays are often used for range switching, which has been an obstacle to miniaturization. SUMMARY OF THE INVENTION It is an object of the present invention to realize a voltage applied current measuring device that does not require a range switching circuit and is faster and more compact.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するため
に、本発明においては、被試験デバイスの端子に所定の
電圧を印加する演算増幅器を設けている。上記演算増幅
器の出力端子と上記被試験デバイスの端子の間に、電流
検出用のダイオード逆並列回路を設ける。上記ダイオー
ド逆並列回路に発生する電圧は、引き算回路により検出
される。上記引き算回路の後段には、上記逆並列回路を
構成するダイオードと同一の特性を持つ１組のダイオー
ドが接続される。上記１組のダイオードの他端は、それ
ぞれ正極性の対数増幅器及び負極性の対数増幅器に入力
する。上記正極性の対数増幅器及び負極性の対数増幅器
の出力電圧は、引き算回路の出力に接続された極性判別
用コンパレータによってＡＤ変換器への出力がスイッチ
で切り替えられる。上記対数増幅器の出力は、ＡＤ変換
器によりディジタルに変換され、極性判別用コンパレー
タの出力と共に演算手段に入力し、電流測定が実行され
る。なお、上記ダイオード逆並列回路に並列に抵抗器を
接続し、同時に１組のダイオードの各ダイオードに並列
に上記抵抗器と同一の抵抗器をそれぞれ接続してもよ
い。To achieve the above object, the present invention provides an operational amplifier for applying a predetermined voltage to a terminal of a device under test. A diode antiparallel circuit for current detection is provided between the output terminal of the operational amplifier and the terminal of the device under test. The voltage generated in the diode anti-parallel circuit is detected by the subtraction circuit. A set of diodes having the same characteristics as the diodes forming the anti-parallel circuit are connected to the subsequent stage of the subtraction circuit. The other ends of the set of diodes are input to a positive logarithmic amplifier and a negative logarithmic amplifier, respectively. The output voltage of the positive logarithmic amplifier and the negative logarithmic amplifier is switched to the output to the AD converter by the polarity discrimination comparator connected to the output of the subtraction circuit. The output of the logarithmic amplifier is converted into a digital signal by the AD converter, and is input to the calculating means together with the output of the polarity determining comparator, and the current measurement is executed. A resistor may be connected in parallel to the diode anti-parallel circuit, and at the same time, the same resistor as the resistor may be connected in parallel to each diode of one set of diodes.
【０００６】[0006]
【作用】上記のように構成された電圧印加電流測定装置
においては、従来のようなレンジ切り替え回路が無く、
１回の測定で必要とする電流値を測定でき、レンジ切り
替えのためのリレーが使用されないため、高速で、小型
化した電圧印加電流測定装置を実現できる。In the voltage applied current measuring device configured as described above, there is no range switching circuit as in the prior art,
A required current value can be measured in one measurement, and a relay for switching the range is not used. Therefore, a high-speed and downsized voltage application current measuring device can be realized.
【０００７】[0007]
【実施例】図１に本発明の実施例を示す。図中１は演算
増幅器、２は被試験デバイス、ＥＣは被試験デバイス２
の端子２Ａと２Ｂの間に与えるべき直流電圧を発生する
直流電圧源、４は被試験デバイス２の端子２Ａ及び２Ｂ
間に与えた電圧Ｖ0 を演算増幅器１に負帰還させる帰還
回路、５は電流測定回路、７はダイオードの逆並列回路
をそれぞれ示す。EXAMPLE FIG. 1 shows an example of the present invention. In the figure, 1 is an operational amplifier, 2 is a device under test, and EC is a device under test 2
DC voltage source 4 for generating a DC voltage to be applied between the terminals 2A and 2B of the device 2 and terminals 2A and 2B of the device under test 2
A feedback circuit for negatively feeding back the voltage V 0 applied between them to the operational amplifier 1 is a current measuring circuit, and 7 is an antiparallel circuit of diodes.
【０００８】本実施例においては電流測定回路５のＡＤ
変換器５Ｂの前段側に対数増幅器８を設けた構造を特徴
とする。本実施例の対数増幅器８は、ＶO ＝ＫｌｏｇＩ
L′ ／Ｉ2 の特性を示す。ここでＫはスケールファクタ
であり、出力側につけられた抵抗により決まる。図２に
基準電流Ｉ2 を１μＡとし、Ｋを１、３、５とした時
の、ＩL′ −ＶO 特性を示す。つまり、入力電流ＩL′
は出力電圧ＶO に対し対数特性を示す。この結果、ＡＤ
変換器５Ｂに与える電圧信号のレベルを切り替えること
もなく、電流値の小さい部分は高分解能で読み取り、大
電流の部分は比較的低い分解能でＡＤ変換器５Ｂで読み
取ることができる。対数増幅器８は、引き算回路５Ａの
出力電圧が正か負かによって、正電圧用及び負電圧用の
対数増幅器が選択され、ＡＤ変換器５Ｂへの入力がスイ
ッチにより切り替えられる。また、引き算回路５Ａの出
力電圧が正か負かの選択信号は演算手段５Ｃにも入力さ
れ電流測定が実行される。In this embodiment, the AD of the current measuring circuit 5 is used.
The structure is characterized in that a logarithmic amplifier 8 is provided on the front side of the converter 5B. In the logarithmic amplifier 8 of this embodiment, V O = KlogI
L '/ I shows the second characteristic. Here, K is a scale factor, which is determined by the resistance attached to the output side. And 1μA a reference current I 2 in FIG. 2, when the 1,3,5 a K, indicating the I L '-V O characteristics. That is, the input current I L ′
Indicates a logarithmic characteristic with respect to the output voltage V O. As a result, AD
Without switching the level of the voltage signal applied to the converter 5B, a portion with a small current value can be read with high resolution and a portion with a large current can be read with a relatively low resolution by the AD converter 5B. The logarithmic amplifier 8 selects a positive voltage or negative voltage logarithmic amplifier depending on whether the output voltage of the subtraction circuit 5A is positive or negative, and the input to the AD converter 5B is switched by a switch. The selection signal indicating whether the output voltage of the subtraction circuit 5A is positive or negative is also input to the calculation means 5C and the current measurement is executed.
【０００９】なお、ダイオードの逆並列回路７に流れる
電流が小さい時、逆並列にしたダイオードが両者共ＯＦ
Ｆになり回路が不安定になる。このため、微小電流検出
用の抵抗器を、これらダイオードと並列に接続してもよ
い。この場合、引き算回路５Ａの出力に接続した２つの
ダイオードにも、それぞれ同一の抵抗器を並列に接続す
る必要がある。When the current flowing through the anti-parallel circuit 7 of the diodes is small, both of the anti-parallel diodes are OF.
It becomes F and the circuit becomes unstable. Therefore, a resistor for detecting a minute current may be connected in parallel with these diodes. In this case, it is necessary to connect the same resistor in parallel to the two diodes connected to the output of the subtraction circuit 5A.
【００１０】[0010]
【発明の効果】本発明は、以上説明したように構成され
ているので、レンジ切り替え回路が無く、従来に比べて
高速に、１度の電流測定で電流値を測定できる。また、
レンジ切り替え用のリレーが無いため小型化できる。Since the present invention is constructed as described above, there is no range switching circuit, and the current value can be measured at a higher speed as compared with the prior art by one current measurement. Also,
Since there is no range switching relay, it can be downsized.
【図１】本発明の電圧印加電流測定装置の回路ブロック
図である。FIG. 1 is a circuit block diagram of a voltage applied current measuring device of the present invention.
【図２】対数増幅器の入出力特性図である。FIG. 2 is an input / output characteristic diagram of a logarithmic amplifier.
【図３】従来の電圧印加電流測定装置の回路ブロック図
である。FIG. 3 is a circuit block diagram of a conventional voltage applied current measuring device.
１、６Ａ 演算増幅器 ２ 被試験デバイス ２Ａ、２Ｂ 端子 ３ 電流検出用抵抗器 ４ 帰還回路 ５ 電流測定回路 ５Ａ 引き算回路 ５Ｂ ＡＤ変換器 ５Ｃ 演算手段 ６ レンジ切替回路 ６Ｂ 入力抵抗器 ６Ｃ、７ ダイオード逆並列回路 ６Ｄ 抵抗切替回路 ６Ｅ １組のダイオード ８ 対数増幅器 ８Ａ 極性判別用コンパレータ 1, 6A Operational amplifier 2 Device under test 2A, 2B terminal 3 Current detection resistor 4 Feedback circuit 5 Current measurement circuit 5A Subtraction circuit 5B AD converter 5C Calculation means 6 Range switching circuit 6B Input resistor 6C, 7 Diode antiparallel Circuit 6D Resistance switching circuit 6E One set of diodes 8 Logarithmic amplifier 8A Polarity discrimination comparator
Claims (2)
所定の電圧を印加する演算増幅器（１）と、 上記演算増幅器（１）の出力端子と上記被試験デバイス
（２）の端子（２Ａ）の間に接続した電流検出用のダイ
オード逆並列回路（７）と、 上記ダイオード逆並列回路（７）に発生する電圧を取り
出す引き算回路（５Ａ）と、 この引き算回路（５Ａ）の後段に接続され、上記ダイオ
ード逆並列回路（７）を構成するダイオードと同一の特
性を持つ１組のダイオード（６Ｅ）と、 上記１組のダイオード（６Ｅ）の他端を入力とする、正
極性の対数増幅器及び負極性の対数増幅器で構成される
対数増幅器（８）と、 上記正極性の対数増幅器及び負極性の対数増幅器の出力
電圧のＡＤ変換器（５Ｂ）への接続スイッチを切り替え
る極性判別用コンパレータ（８Ａ）と、 以上を具備することを特徴とする電圧印加電流測定装
置。1. An operational amplifier (1) for applying a predetermined voltage to a terminal (2A) of a device under test (2), an output terminal of the operational amplifier (1) and a terminal (2) of the device under test (2). 2A), a diode anti-parallel circuit (7) for current detection, a subtraction circuit (5A) for extracting the voltage generated in the diode anti-parallel circuit (7), and a subtraction circuit (5A) in the subsequent stage. A pair of diodes (6E) that are connected and have the same characteristics as the diodes that form the diode anti-parallel circuit (7), and the logarithm of positive polarity that receives the other end of the diode (6E) as an input A logarithmic amplifier (8) composed of an amplifier and a logarithmic amplifier of negative polarity, and a polarity discriminating controller for switching a connection switch of the output voltage of the logarithmic amplifier of positive polarity and the logarithmic amplifier of negative polarity to the AD converter (5B). Voltage source current measurement device comprising a regulator (8A), that comprises more.
抗器を接続し、１組のダイオード（６Ｅ）の各ダイオー
ドに並列に、上記抵抗器と同一の抵抗器をそれぞれ接続
した請求項１記載の電圧印加電流測定装置。2. A resistor is connected in parallel to the diode anti-parallel circuit (7), and the same resistor as the resistor is connected in parallel to each diode of the set of diodes (6E). The voltage applied current measuring device described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6210508A JPH0854424A (en) | 1994-08-10 | 1994-08-10 | Current application voltage measuring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6210508A JPH0854424A (en) | 1994-08-10 | 1994-08-10 | Current application voltage measuring instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0854424A true JPH0854424A (en) | 1996-02-27 |
Family
ID=16590536
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6210508A Pending JPH0854424A (en) | 1994-08-10 | 1994-08-10 | Current application voltage measuring instrument |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0854424A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006292383A (en) * | 2005-04-05 | 2006-10-26 | Honda Motor Co Ltd | Current detection device and electric steering device |
| US7352193B2 (en) | 2002-12-11 | 2008-04-01 | Advantest Corporation | Voltage-impressed current measuring apparatus and current buffers with switches used therefor |
| CN103267882A (en) * | 2013-05-23 | 2013-08-28 | 南京大手笔电子科技有限公司 | Zero-pressure-dropping device |
| CN103278795A (en) * | 2013-05-28 | 2013-09-04 | 南京五耀电子科技有限公司 | Secondary metering pressure drop eliminating device |
-
1994
- 1994-08-10 JP JP6210508A patent/JPH0854424A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7352193B2 (en) | 2002-12-11 | 2008-04-01 | Advantest Corporation | Voltage-impressed current measuring apparatus and current buffers with switches used therefor |
| JP2006292383A (en) * | 2005-04-05 | 2006-10-26 | Honda Motor Co Ltd | Current detection device and electric steering device |
| JP4585358B2 (en) * | 2005-04-05 | 2010-11-24 | 本田技研工業株式会社 | Electric steering device |
| CN103267882A (en) * | 2013-05-23 | 2013-08-28 | 南京大手笔电子科技有限公司 | Zero-pressure-dropping device |
| CN103278795A (en) * | 2013-05-28 | 2013-09-04 | 南京五耀电子科技有限公司 | Secondary metering pressure drop eliminating device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20030218 |