JPS61160121A - Constant current circuit - Google Patents

Constant current circuit

Info

Publication number
JPS61160121A
JPS61160121A JP27768684A JP27768684A JPS61160121A JP S61160121 A JPS61160121 A JP S61160121A JP 27768684 A JP27768684 A JP 27768684A JP 27768684 A JP27768684 A JP 27768684A JP S61160121 A JPS61160121 A JP S61160121A
Authority
JP
Japan
Prior art keywords
constant current
circuit
temperature
temperature coefficient
current
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
Application number
JP27768684A
Other languages
Japanese (ja)
Other versions
JPH0820915B2 (en
Inventor
Kaoru Izawa
伊澤　芳
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.)
Rohm Co Ltd
Original Assignee
Rohm 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 Rohm Co Ltd filed Critical Rohm Co Ltd
Priority to JP59277686A priority Critical patent/JPH0820915B2/en
Publication of JPS61160121A publication Critical patent/JPS61160121A/en
Publication of JPH0820915B2 publication Critical patent/JPH0820915B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F3/00—Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
    • G05F3/02—Regulating voltage or current
    • G05F3/08—Regulating voltage or current wherein the variable is dc
    • G05F3/10—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics
    • G05F3/16—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices
    • G05F3/20—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices using diode- transistor combinations
    • G05F3/26—Current mirrors

Abstract

PURPOSE:To suppress temperature dependence by forming a temperature correcting circuit for entering a constant current having a specific temperature factor and generating a constant current to which a temperature factor reversed against said temperature factor. CONSTITUTION:A current mirror circuit 56 consists of transistors (TRs) 34, 36 of which the ratio of emitter areas is set up to 1:1 and resistors 44, 46, a current mirror circuit 58 consists of TRs 38, 40 of which the ratio of emitter areas is set up to n:1, a TR42 and a resistor 48 and a constant current circuit having a positive temperature factor is constituted of the combination of these current mirror circuits 56, 58. The temperature correcting circuit 60 consists of TRs 62, 64 and a resistor 66. A constant current circuit having a negative temperature factor is constituted of the diode consisting of the TR62, the TR64 and the resistor 66. In an output current Iref obtained by the sum of both the constant current circuits, the positive and negative temperature factors are offset and a constant current having no temperature factor can be obtained by setting up a circuit constant properly.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、定電流出力の温度依存性を改善した定電流
回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a constant current circuit with improved temperature dependence of constant current output.

〔従来の技術〕[Conventional technology]

従来、電源電圧の変動に対する依存性を持たない定電流
を得るために、第２図ないし第４図に示すような定電流
回路が用いられている。Conventionally, constant current circuits as shown in FIGS. 2 to 4 have been used to obtain a constant current that is not dependent on variations in power supply voltage.

すなわち、第２図に示す定電流回路は、トランジスタ２
、ダイオード４．６および抵抗８、ＩＯから構成され、
電源端子１２と接離点との間には電源から電圧ＶＣＣが
加えられ、出力端子１４にはトランジスタ２の定電流動
作によって定電流ＩＯが、図示していない負荷回路から
引き込まれる。That is, the constant current circuit shown in FIG.
, consists of a diode 4.6 and a resistor 8, IO,
A voltage VCC is applied from the power supply between the power supply terminal 12 and the contact point, and a constant current IO is drawn into the output terminal 14 from a load circuit (not shown) by the constant current operation of the transistor 2.

第３図に示す定電流回路は、トランジスタ１６．１８．
２０および抵抗２２．２４．２６．２８で構成され、電
源端子３０と接地点との間には電源から電圧ＶＣＣが加
えられ、出力端子３２にはトランジスタ２の定電流動作
によって定電流ＩＯが、図示していない負荷回路から引
き込まれる。この場合、トランジスタ１６．１８は電流
ミラー回路を構成し、トランジスタ２０はこの電流ミラ
ー回路に対する起動回路を構成している。The constant current circuit shown in FIG. 3 includes transistors 16, 18 .
20 and resistors 22, 24, 26, and 28, a voltage VCC is applied from the power supply between the power supply terminal 30 and the ground point, and a constant current IO is applied to the output terminal 32 by the constant current operation of the transistor 2. It is drawn in from a load circuit (not shown). In this case, transistors 16, 18 constitute a current mirror circuit, and transistor 20 constitutes a starting circuit for this current mirror circuit.

また、第４図に示す定電流回路は、トランジスタ３４．
３６．３８．４０．４２および抵抗４４．４６．４８か
らなる一対の電流ミラー回路で構成されている。すなわ
ち、電源端子５０と接地点との間には電源から電圧Ｖｃ
ｃが加えられ、出力端子５２にはトランジスタ２の定電
流動作によって定電流１０が、図示していない負荷回路
から引き込まれる。Further, the constant current circuit shown in FIG. 4 includes transistors 34.
It consists of a pair of current mirror circuits consisting of a resistor 36, 38, 40, 42 and a resistor 44, 46, 48. That is, a voltage Vc is applied from the power supply between the power supply terminal 50 and the ground point.
c is applied, and a constant current 10 is drawn into the output terminal 52 by the constant current operation of the transistor 2 from a load circuit (not shown).

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

このような定電流回路では、電源電圧に対する依存度が
低く、電源電圧が変動しても安定した定電流を取り出す
ことができるが、温度変化に対して定電流値が変動する
欠点を持っている。すなわち、第２図および第３図に示
す定電流回路では負の温度係数を持っており、第４図に
示す定電流回路では、抵抗４８の温度係数に依存するた
め、正の温度係数を持っている。This kind of constant current circuit has low dependence on the power supply voltage and can extract a stable constant current even when the power supply voltage fluctuates, but it has the disadvantage that the constant current value fluctuates with temperature changes. . That is, the constant current circuits shown in FIGS. 2 and 3 have a negative temperature coefficient, and the constant current circuit shown in FIG. 4 has a positive temperature coefficient because it depends on the temperature coefficient of the resistor 48. ing.

そこで、この発明は、温度依存性を改善した定電流回路
を提供しようとするものである。Therefore, the present invention aims to provide a constant current circuit with improved temperature dependence.

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

すなわち、この発明は、特定の温度係数を持つ定電流回
路において、前記特定の温度係数を持つ定電流を取り込
んでその温度係数とは逆の温度係数を付加した定電流を
発生する温度補正回路を設置し、前記特定の温度係数を
持つ定電流に対して前記温度補正回路が出力する逆の温
度係数を加算して温度係数を相殺した定電流を出力する
ことを特徴とするものである。That is, in a constant current circuit having a specific temperature coefficient, the present invention includes a temperature correction circuit that takes in a constant current having the specific temperature coefficient and generates a constant current to which a temperature coefficient opposite to the temperature coefficient is added. The present invention is characterized in that it adds an inverse temperature coefficient output from the temperature correction circuit to the constant current having the specific temperature coefficient, and outputs a constant current with the temperature coefficient offset.

〔作　用〕[For production]

したがって、この発明は、たとえば、正の温度係数を持
つ定電流に負の温度係数を与えて得られる負の温度係数
を持つ定電流と、正の温度係数を持つ定電流とを加算し
て温度係数を相殺し、温度依存性のない定電流を形成し
ている。Therefore, in the present invention, for example, a constant current having a negative temperature coefficient obtained by giving a negative temperature coefficient to a constant current having a positive temperature coefficient, and a constant current having a positive temperature coefficient are added together to generate a temperature. The coefficients cancel each other out, forming a constant current with no temperature dependence.

〔実施例〕〔Example〕

以下、この発明の実施例を図面を参照して詳細に説明す
る。Embodiments of the present invention will be described in detail below with reference to the drawings.

第１図はこの発明の定電流回路の実施例を示し、第４図
に示す定電流回路と同一部分には、同一符号を付しであ
る。FIG. 1 shows an embodiment of a constant current circuit of the present invention, and the same parts as those of the constant current circuit shown in FIG. 4 are given the same reference numerals.

この定電流回路は、一対の電流ミラー回路５６．５８か
らなる定電流回路に温度補正回路６０を付加したもので
ある。This constant current circuit has a temperature correction circuit 60 added to a constant current circuit consisting of a pair of current mirror circuits 56 and 58.

電流ミラー回路５６は、エミツタ面積比を１：１に設定
したトランジスタ３４．３６に抵抗４４．４６を付加し
て構成され、また、電流ミラー回路５８はエミツタ面積
比をｎ：１に設定したトランジスタ３８．４０にトラン
ジスタ４２を付加するとともに、トランジスタ３８のエ
ミッタ側に抵抗４８を付加したものであり、これら電流
ミラー回路５６．５８の組み合わせで正の温度係数を持
つ定電流回路が構成されている。The current mirror circuit 56 is constructed by adding a resistor 44.46 to a transistor 34.36 whose emitter area ratio is set to 1:1, and the current mirror circuit 58 is composed of a transistor whose emitter area ratio is set to n:1. A transistor 42 is added to 38.40, and a resistor 48 is added to the emitter side of the transistor 38.The combination of these current mirror circuits 56.58 constitutes a constant current circuit with a positive temperature coefficient. .

また、温度補正回路６０はトランジスタ６２．６４およ
び抵抗６６からなり、トランジスタ６２は、ベース・コ
レクタが共通化されてダイオードとして構成されている
。すなわち、このトランジスタ６２からなるダイオード
、トランジスタ６４および抵抗６６によって、負の温度
係数を持つ定電流回路が構成されている。Further, the temperature correction circuit 60 includes transistors 62, 64 and a resistor 66, and the transistor 62 has a common base and collector and is configured as a diode. That is, the diode made up of the transistor 62, the transistor 64, and the resistor 66 constitute a constant current circuit having a negative temperature coefficient.

以上の構成において、その動作を説明する。The operation of the above configuration will be explained.

電流ミラー回路５６．５８に流れる定電流をＩＯｌこの
定電流Ｉｏを取り込んで流れる温度補正回路６０の定電
流を１１とすると、出力電流Ｉ　ｒｅｆは、 Ｉ、、ｆ＝１゜＋■１　　　　　・・・・（１）となる
。Assuming that the constant current flowing through the current mirror circuits 56 and 58 is IOl, and the constant current of the temperature correction circuit 60 that takes in this constant current Io and flows through it is 11, the output current Iref is I,, f=1°+■1... ...(1).

抵抗４８の抵抗値をＲ３とすると、定電流Ｉ０は、 Ｉ（１＝Ｖｙ　Ｉｎｎ／Ｒ＋　　　　”　”（２）とな
る。ただし、ｎは前記エミツタ面積比、■。Assuming that the resistance value of the resistor 48 is R3, the constant current I0 is I(1=Vy Inn/R+ `` '' (2). However, n is the emitter area ratio, and ■.

はボルツマン定数Ｔ、絶対温度Ｔおよび電子の電荷ｑか
らなるＫＴ／ｑである。したがって、定電流ＩＯは、正
の温度係数を持っている。is KT/q, which consists of Boltzmann's constant T, absolute temperature T, and electron charge q. Therefore, constant current IO has a positive temperature coefficient.

また、抵抗６６の抵抗値をＲ２、トランジスタ６２のベ
ース・エミッタ間電圧を■。とすると、電流１１は、 Ｉ　ｒ　＃Ｖ　ｍ！／　Ｒｚ　　　　　　・・・・（３
）となる。Also, the resistance value of the resistor 66 is R2, and the voltage between the base and emitter of the transistor 62 is ■. Then, the current 11 is I r #V m! / Rz...(3
).

この場合、ダイオードとしてのトランジスタ６２の温度
係数は、凡そ−２ｍ　Ｖ　／　”Ｃであるから、そのベ
ース・エミッタ間電圧ｖ１は、この温度係数を持って変
動し、電流Ｉ、も、この温度係数に依存することになる
。In this case, since the temperature coefficient of the transistor 62 as a diode is approximately -2 mV/''C, its base-emitter voltage v1 fluctuates with this temperature coefficient, and the current I also varies with this temperature coefficient. It will depend on.

そこで、両者の和で与えられる出力電流Ｉ　ｒｅｆは、
正負の温度係数を相殺したものとなり、回路定数を適当
に設定することより、温度係数を持たない定電流を得る
ことができる。Therefore, the output current I ref given by the sum of both is
The positive and negative temperature coefficients cancel each other out, and by appropriately setting the circuit constants, a constant current having no temperature coefficient can be obtained.

たとえば、エミツタ面積比ｎを３、抵抗４８の抵抗値Ｒ
，−２８０（Ω）、抵抗６６の抵抗値Ｒ２＝６　（ｋΩ
）、ヘース・エミッタ間電圧Ｖ　ｔｒｙ　＝　０゜６９
　（Ｖ）　　（１００μ／２５℃）とすると、式（２）
から定電流Ｔｏ＝１００（μＡ）、式（３）から定電流
Ｉ、＝１１０（μＡ）、温度変化率はそれぞれ定電流Ｉ
０が＋０．３μＡ　／　”Ｃ１電流１１が−０，３μＡ
　／　’ｃとなるので、弐（１）から出力電流１ｒ、−
ｒ　＝　２１０　（μＡ）となり、殆ど温度依存性を持
たない定電流が得られる。For example, if the emitter area ratio n is 3 and the resistance value R of the resistor 48 is
, -280 (Ω), resistance value R2 of resistor 66 = 6 (kΩ
), Heath-emitter voltage V try = 0°69
(V) (100μ/25℃), formula (2)
From equation (3), constant current To = 100 (μA), constant current I, = 110 (μA), temperature change rate is constant current I, respectively.
0 is +0.3μA / “C1 current 11 is -0.3μA
/ 'c, so the output current 1r, - from 2(1)
r = 210 (μA), and a constant current with almost no temperature dependence can be obtained.

また、半導体集積回路によって抵抗を構成する際、その
温度計数が問題となるが、これも考慮して定数を容易に
設定することができる。Further, when a resistor is constructed using a semiconductor integrated circuit, its temperature coefficient becomes a problem, but the constant can be easily set taking this into consideration.

なお、このような定電流回路から得られる温度特性を持
たない出力電流を抵抗に流すことにより、温度特性を持
たない定電圧を発生する基準定電圧源が実現できる。Note that by passing an output current that does not have temperature characteristics obtained from such a constant current circuit through a resistor, a reference constant voltage source that generates a constant voltage that does not have temperature characteristics can be realized.

また、実施例では、特定の温度係数として正の温度係数
を持つ定電流回路に対してその温度係数とは逆の関係を
持つ負の温度係数を待つ温度補正回路を付加し、温度特
性を相殺しているが、負の温度係数を持つ定電流回路に
対して正の温度特性を持つ温度補正回路を付加してもよ
い。In addition, in the embodiment, a temperature correction circuit is added to a constant current circuit having a positive temperature coefficient as a specific temperature coefficient, and waits for a negative temperature coefficient having an inverse relationship to the temperature coefficient, thereby canceling out the temperature characteristics. However, a temperature correction circuit having a positive temperature characteristic may be added to a constant current circuit having a negative temperature coefficient.

〔発明の効果〕〔Effect of the invention〕

以上説明したように、この発明によれば、簡単な構成に
よって温度依存性を抑制した定電流回路を得ることがで
きる。As described above, according to the present invention, a constant current circuit with suppressed temperature dependence can be obtained with a simple configuration.

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

第１図はこの発明の定電流回路の実施例を示す回路図、
第２図ないし第４図は従来の定電流回路を示す回路図で
ある。 ５６．５８・・・電流ミラー回路、６０・・・温度補正
回路。 第１図 第３図 第４図FIG. 1 is a circuit diagram showing an embodiment of the constant current circuit of the present invention,
2 to 4 are circuit diagrams showing conventional constant current circuits. 56.58...Current mirror circuit, 60...Temperature correction circuit. Figure 1 Figure 3 Figure 4

Claims (2)

【特許請求の範囲】[Claims] （１）特定の温度係数を持つ定電流回路において、前記
特定の温度係数を持つ定電流を取り込んでその温度係数
とは逆の温度係数を付加した定電流を発生する温度補正
回路を設置し、前記特定の温度係数を持つ定電流に対し
て前記温度補正回路が出力する逆の温度係数を加算して
温度係数を相殺した定電流を出力することを特徴とする
定電流回路。(1) In a constant current circuit having a specific temperature coefficient, a temperature correction circuit is installed that takes in the constant current having the specific temperature coefficient and generates a constant current to which a temperature coefficient opposite to the temperature coefficient is added, A constant current circuit characterized in that a constant current having the specific temperature coefficient is added with an inverse temperature coefficient outputted by the temperature correction circuit to output a constant current with the temperature coefficient canceled. （２）前記温度補正回路は、正の温度係数を持つ定電流
を取り込み、ダイオードの負の温度係数を用いて負の温
度係数を持つ定電流を形成する電流ミラー回路を用いた
ことを特徴とする特許請求の範囲の第１項に記載の定電
流回路。(2) The temperature correction circuit is characterized by using a current mirror circuit that takes in a constant current having a positive temperature coefficient and forms a constant current having a negative temperature coefficient using the negative temperature coefficient of the diode. A constant current circuit according to claim 1.
JP59277686A 1984-12-31 1984-12-31 Constant current circuit Expired - Lifetime JPH0820915B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59277686A JPH0820915B2 (en) 1984-12-31 1984-12-31 Constant current circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59277686A JPH0820915B2 (en) 1984-12-31 1984-12-31 Constant current circuit

Publications (2)

Publication Number Publication Date
JPS61160121A true JPS61160121A (en) 1986-07-19
JPH0820915B2 JPH0820915B2 (en) 1996-03-04

Family

ID=17586888

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59277686A Expired - Lifetime JPH0820915B2 (en) 1984-12-31 1984-12-31 Constant current circuit

Country Status (1)

Country Link
JP (1) JPH0820915B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6186491B1 (en) 1998-10-02 2001-02-13 Nec Corporation Sheet feeding apparatus
JP2005228291A (en) * 2004-01-15 2005-08-25 Toyo Commun Equip Co Ltd Reference voltage generating circuit and starter circuit
KR100808726B1 (en) 2005-08-30 2008-02-29 산요덴키가부시키가이샤 Constant current circuit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5866129A (en) * 1981-10-15 1983-04-20 Toshiba Corp Constant current source circuit
JPS5880715A (en) * 1981-11-06 1983-05-14 Toshiba Corp Current source circuit
JPS58144920A (en) * 1982-02-23 1983-08-29 Toshiba Corp Constant current circuit

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5866129A (en) * 1981-10-15 1983-04-20 Toshiba Corp Constant current source circuit
JPS5880715A (en) * 1981-11-06 1983-05-14 Toshiba Corp Current source circuit
JPS58144920A (en) * 1982-02-23 1983-08-29 Toshiba Corp Constant current circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6186491B1 (en) 1998-10-02 2001-02-13 Nec Corporation Sheet feeding apparatus
JP2005228291A (en) * 2004-01-15 2005-08-25 Toyo Commun Equip Co Ltd Reference voltage generating circuit and starter circuit
KR100808726B1 (en) 2005-08-30 2008-02-29 산요덴키가부시키가이샤 Constant current circuit

Also Published As

Publication number Publication date
JPH0820915B2 (en) 1996-03-04

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