JPH0556531B2 - - Google Patents
Info
- Publication number
- JPH0556531B2 JPH0556531B2 JP24289984A JP24289984A JPH0556531B2 JP H0556531 B2 JPH0556531 B2 JP H0556531B2 JP 24289984 A JP24289984 A JP 24289984A JP 24289984 A JP24289984 A JP 24289984A JP H0556531 B2 JPH0556531 B2 JP H0556531B2
- Authority
- JP
- Japan
- Prior art keywords
- transistor
- emitter
- circuit
- collector
- voltage
- 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 - Fee Related
Links
- 238000010586 diagram Methods 0.000 description 3
- 230000010354 integration Effects 0.000 description 1
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
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、集積回路化に好適な定電回路に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a constant current circuit suitable for integration into an integrated circuit.
従来例の構成とその問題点
従来、電源電圧に依存しない定電圧素子として
ツエナーダイオードが広く用いられていたが、近
年、集積回路の低電圧化に伴ない、ツエナーダイ
オードの使用が困難になつてきた。これに代わる
ものとして、第１図に示すような、トランジスタ
のベース・エミツタ電圧を利用した低電圧回路が
用いられる。以下、トランジスタのベース・エミ
ツタ電圧を用いた定電圧回路について説明する。Conventional configurations and their problems In the past, Zener diodes were widely used as constant voltage elements that did not depend on the power supply voltage, but in recent years, as the voltage of integrated circuits has become lower, it has become difficult to use Zener diodes. Ta. As an alternative to this, a low voltage circuit using the base-emitter voltage of a transistor, as shown in FIG. 1, is used. A constant voltage circuit using the base-emitter voltage of a transistor will be described below.
第１図において、１は電流源、２は定電圧出力
端子、３は接地端子、４はNPNトランジスタ、
５，６は抵抗である。いま、抵抗５，６の値をそ
れぞれR1，R2、トランジスタ４のベース、エミ
ツタ電圧をVBEとすると、出力端子の電圧VOは
VO＝〔（R1＋R2）／R2〕×VBE
となる。一方、VBEは、電流源の電流値に対する
依存性が小さい（電流値が２倍になつた時、約17
ｍｖ増加する）ため、出力端子の電圧もほぼ一定
電圧となり、この結果、第１図の回路は定電圧回
路として動作する。 In Figure 1, 1 is a current source, 2 is a constant voltage output terminal, 3 is a ground terminal, 4 is an NPN transistor,
5 and 6 are resistances. Now, if the values of resistors 5 and 6 are R 1 and R 2 respectively, and the base and emitter voltages of transistor 4 are V BE , then the voltage V O at the output terminal is V O = [(R 1 + R 2 )/R 2 ] ×V BE . On the other hand, V BE has a small dependence on the current value of the current source (approximately 17
mv increases), the voltage at the output terminal also becomes a substantially constant voltage, and as a result, the circuit shown in FIG. 1 operates as a constant voltage circuit.
しかしながら、上記の回路では、トランジスタ
のベース・エミツタ電圧VBEが、−1.8ｍｖ／degの
温度依存性をもつため、定電圧回路の出力電圧
も、−1.8×（R1＋R2）／R2ｍｖ／degの温度依存
性をもち、出力電圧の温度特性が悪いという問題
点を有していた。 However, in the above circuit, the base-emitter voltage V BE of the transistor has a temperature dependence of -1.8 mv/deg, so the output voltage of the constant voltage circuit is also -1.8 x (R 1 + R 2 )/R 2 It has a temperature dependence of mv/deg and has a problem in that the temperature characteristics of the output voltage are poor.
発明の目的
本発明は、上記従来の問題点を解決するもの
で、ツエナーダイオードより低い電圧で使用で
き、しかも電圧の温度依存性の小さな定電圧回路
を提供することを目的とする。OBJECTS OF THE INVENTION The present invention solves the above conventional problems, and aims to provide a constant voltage circuit that can be used at a lower voltage than a Zener diode and has less temperature dependence of voltage.
発明の構成
本発明は、エミツタ及びベースを各々共通接続
し第１の電流ミラー回路を成す一導電型（PNP）
の第１、第２のトランジスタ８，７と、前記第１
のトランジスタ８のエミツタに接続された出力端
子２に一端を接続した電流源１と、エミツタに第
１の抵抗１２を有した逆導電型（NPN）の第３
のトランジスタ１１と、前記第１のトランジスタ
８のベース・コレクタの接続点と前記第３のトラ
ンジスタ１１のコレクタとの間に接続された第２
の抵抗９と、前記第３のトランジスタのエミツタ
回路とエミツタを共通接続すると共にベースを共
通接続して第２の電流ミラー回路を成し、前記第
２トランジスタ７のコレクタ電流をコレクタに入
力する逆導電型（NPN）の第４のトランジスタ
１０と、前記第４のトランジスタ１０のエミツタ
がエミツタに接続され、前記第３のトランジスタ
１１のコレクタがベースに接続されると共に前記
出力端子２がコレクタに接続された逆導電型
（NPN）の第５のトランジスタ４とを備え、前記
第３のトランジスタ１１のエミツタ面積が前記第
４のトランジスタ１０のエミツタ面積よりも実質
的に大きいことを特徴とする定電圧回路であり、
この構成により、出力電圧が約2.4Vと小さく、
かつ出力電圧の温度依存性の小さい定電圧回路を
実現できる。Structure of the Invention The present invention provides a one-conductivity type (PNP) in which the emitter and base are each commonly connected to form a first current mirror circuit.
the first and second transistors 8, 7, and the first
a current source 1 whose one end is connected to the output terminal 2 connected to the emitter of the transistor 8;
a second transistor connected between the base-collector connection point of the first transistor 8 and the collector of the third transistor 11;
resistor 9, the emitter circuit and emitter of the third transistor are commonly connected, and the bases are commonly connected to form a second current mirror circuit, and the collector current of the second transistor 7 is input to the collector. A fourth transistor 10 of conductivity type (NPN), the emitter of the fourth transistor 10 is connected to the emitter, the collector of the third transistor 11 is connected to the base, and the output terminal 2 is connected to the collector. and a fifth transistor 4 of the opposite conductivity type (NPN), wherein the emitter area of the third transistor 11 is substantially larger than the emitter area of the fourth transistor 10. is a circuit,
This configuration allows the output voltage to be as low as approximately 2.4V.
In addition, a constant voltage circuit in which the temperature dependence of the output voltage is small can be realized.
実施例の説明
第２図に、本発明による定電圧回路の回路例を
示す。図において、１は電流源、２は定電圧出力
端子、３は接地端子、４はNPNトランジスタ、
７，８はエミツタ面積の等しいPNPトランジス
タ、１０はNPNトランジスタ、１１はトランジ
スタ１０のエミツタ面積よりも実質的に大きなエ
ミツタ面積を有するNPNトランジスタ、９，１
２は抵抗である。DESCRIPTION OF EMBODIMENTS FIG. 2 shows a circuit example of a constant voltage circuit according to the present invention. In the figure, 1 is a current source, 2 is a constant voltage output terminal, 3 is a ground terminal, 4 is an NPN transistor,
7 and 8 are PNP transistors with equal emitter areas, 10 is an NPN transistor, 11 is an NPN transistor with an emitter area substantially larger than that of transistor 10, 9, 1
2 is resistance.
以上のように構成された本実施例の定電圧回路
について、以下第２図の回路図にもとづいてその
動作を説明する。 The operation of the constant voltage circuit of this embodiment configured as described above will be explained below based on the circuit diagram of FIG. 2.
第２図において、トランジスタ１０とトランジ
スタ１１のエミツタ面積の比をｎ、抵抗１２の抵
抗値をR3とすると、トランジスタ１１のコレク
タ電流は下のように表わされる。 In FIG. 2, if the ratio of the emitter areas of transistor 10 and transistor 11 is n, and the resistance value of resistor 12 is R3 , then the collector current of transistor 11 is expressed as below.
Ic＝kT・ln(n)／R3
（ｋはボルツマン定数、Ｔは絶対温度）
一方、トランジスタ８のベース・エミツタ電圧
をVBE1、抵抗９の抵抗値をR4、トランジスタ４
のベース・エミツタ電圧をVBEとすると、出力端
子２の電圧VOは、下記のようになる。 Ic=kT・ln(n)/R 3 (k is Boltzmann's constant, T is absolute temperature) On the other hand, the base-emitter voltage of transistor 8 is V BE1 , the resistance value of resistor 9 is R 4 , and transistor 4 is
If the base-emitter voltage of is V BE , then the voltage VO at output terminal 2 is as follows.
VO＝VBE1＋Ic×R4＋VBE
＝VBE1＋kT×ln(n)×R4／R3
＋VBE
ここで、上式の第１項、第２項は、電流源の電
流値にほとんど依存せず、第３項も電流値に対す
る依存性が小さいため、出力電圧もほぼ一定電圧
となる。VO=V BE1 +Ic×R 4 +V BE =V BE1 +kT×ln(n)×R 4 /R 3 +V BEHere , the first and second terms in the above equation mostly depend on the current value of the current source. Since the third term also has a small dependence on the current value, the output voltage is also approximately constant.
次に、本実施例の回路の温度特性について検討
する。出力電圧の温度係数は、
dVO／dT＝dVBE1／dT＋dVBE／dT＋ｋ×ln(n)×R4／R3
ここで、
dVBE1／dT＝dVBE／dT−1.8ｍＶ／deg
であり、一方、ｋ×ln(n)×R4／R3は正数であるの
で、適当なR4／R3の値を選べば、VOの温度係数をゼ
ロにすることができる。この時、
ｋ×ln(n)×R4／R33.6ｍＶ／deg
となるので、Ｔ＝300〓、VBE1＝VBE＝700ｍＶと
すれば、VO2400ｍＶ
すなわち、本実施例の定電圧回路の出力電圧は
約2.4Vである。 Next, the temperature characteristics of the circuit of this example will be discussed. The temperature coefficient of the output voltage is: dV O /dT = dV BE1 /dT + dV BE /dT + k×ln(n)×R 4 /R 3where , dV BE1 /dT=dV BE /dT−1.8mV/deg, On the other hand, since k×ln(n)×R 4 /R 3 is a positive number, the temperature coefficient of V O can be made zero by selecting an appropriate value of R 4 /R 3 . At this time, k×ln(n)×R 4 /R 3 3.6 mV/deg, so if T = 300〓, V BE1 = V BE = 700 mV, V O 2400 mV, that is, the constant voltage of this example. The output voltage of the circuit is approximately 2.4V.
発明の効果
以上に説明したように、本発明の定電圧回路
は、安定化した出力電圧が2.4Vと小さく、しか
も温度依存性の小さい出力電圧が得られる定電圧
回路を実現するものである。Effects of the Invention As explained above, the constant voltage circuit of the present invention realizes a constant voltage circuit which can obtain a stabilized output voltage as small as 2.4V and an output voltage with small temperature dependence.
第１図は従来のトランジスタのベース・エミツ
タ電圧を用いた定電圧回路の回路図、第２図は本
発明の実施例における定電圧回路の回路図であ
る。
１……電流源、２……定電圧出力端子、３……
接地端子、４，１０，１１……NPNトランジス
タ、７，８……PNPトランジスタ、５，６，９，
１２……抵抗。
FIG. 1 is a circuit diagram of a conventional constant voltage circuit using the base-emitter voltage of a transistor, and FIG. 2 is a circuit diagram of a constant voltage circuit according to an embodiment of the present invention. 1... Current source, 2... Constant voltage output terminal, 3...
Ground terminal, 4, 10, 11...NPN transistor, 7, 8...PNP transistor, 5, 6, 9,
12...Resistance.
Claims (1)
電流ミラー回路を成す一導電型の第１、第２のト
ランジスタと、前記第１のトランジスタのエミツ
タに接続された出力端子に一端を接続した電流源
と、エミツタに第１の抵抗を有した逆導電型の第
３のトランジスタと、前記第１のトランジスタの
ベース・コレクタの接続点と前記第３のトランジ
スタのコレクタとの間に接続された第２の抵抗
と、前記第３のトランジスタのエミツタ回路とエ
ミツタを共通接続すると共にベースを共通接続し
て第２の電流ミラー回路を成し、前記第２のトラ
ンジスタのコレクタ電流をコレクタに入力する逆
導電型の第４のトランジスタと、前記第４のトラ
ンジスタのエミツタがエミツタに接続され、前記
第３のトランジスタのコレクタがベースに接続さ
れると共に前記出力端子がコレクタに接続された
逆導電型の第５のトランジスタとを備え、前記第
３のトランジスタのエミツタ面積が前記第４のト
ランジスタのエミツタ面積よりも実質的に大きい
ことを特徴とする定電圧回路。1. First and second transistors of one conductivity type that have their emitters and bases connected in common to form a first current mirror circuit, and a current source that has one end connected to an output terminal connected to the emitter of the first transistor. a third transistor of opposite conductivity type having a first resistor at its emitter; and a second transistor connected between the base-collector connection point of the first transistor and the collector of the third transistor. a resistor, the emitter circuit and the emitter of the third transistor are commonly connected, and the bases are commonly connected to form a second current mirror circuit, and the collector current of the second transistor is input to the collector. a fifth transistor of an opposite conductivity type, the emitter of the fourth transistor being connected to the emitter, the collector of the third transistor being connected to the base, and the output terminal being connected to the collector. A constant voltage circuit comprising a transistor, wherein an emitter area of the third transistor is substantially larger than an emitter area of the fourth transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24289984A JPS61120219A (en) | 1984-11-16 | 1984-11-16 | Constant voltage circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24289984A JPS61120219A (en) | 1984-11-16 | 1984-11-16 | Constant voltage circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61120219A JPS61120219A (en) | 1986-06-07 |
| JPH0556531B2 true JPH0556531B2 (en) | 1993-08-19 |
Family
ID=17095870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24289984A Granted JPS61120219A (en) | 1984-11-16 | 1984-11-16 | Constant voltage circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61120219A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4674947B2 (en) * | 2000-09-29 | 2011-04-20 | オリンパス株式会社 | Constant voltage output circuit |
-
1984
- 1984-11-16 JP JP24289984A patent/JPS61120219A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61120219A (en) | 1986-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0153807B2 (en) | ||
| JPH05206755A (en) | Reference voltage generating circuit | |
| JPS6326895B2 (en) | ||
| JPH0770935B2 (en) | Differential current amplifier circuit | |
| JP2845654B2 (en) | Current detection circuit | |
| JPH0556531B2 (en) | ||
| JPH0755621Y2 (en) | Reference voltage generation circuit | |
| JPH0543131B2 (en) | ||
| JPS5842886B2 (en) | constant voltage device | |
| JPH067379Y2 (en) | Reference voltage source circuit | |
| JPH0546096Y2 (en) | ||
| JPH0682309B2 (en) | Reference voltage generation circuit | |
| JPH055690Y2 (en) | ||
| JPH0435775Y2 (en) | ||
| JPH0518288B2 (en) | ||
| JPH0642185B2 (en) | Constant voltage circuit | |
| JPH0820915B2 (en) | Constant current circuit | |
| JPS6233365Y2 (en) | ||
| JPS6133519A (en) | Reference voltage source circuit | |
| JPS5855454Y2 (en) | constant current circuit | |
| JPS6297363A (en) | Reference-voltage generating circuit | |
| JPH077905B2 (en) | Voltage comparator | |
| JPH065812B2 (en) | Amplitude limiting circuit | |
| JP2551133B2 (en) | Constant current source circuit | |
| JPS6297362A (en) | Reference-voltage generating circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |