JPH0325046B2 - - Google Patents

Info

Publication number
JPH0325046B2
JPH0325046B2 JP13356384A JP13356384A JPH0325046B2 JP H0325046 B2 JPH0325046 B2 JP H0325046B2 JP 13356384 A JP13356384 A JP 13356384A JP 13356384 A JP13356384 A JP 13356384A JP H0325046 B2 JPH0325046 B2 JP H0325046B2
Authority
JP
Japan
Prior art keywords
voltage
hall element
circuit
current
power supply
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
Application number
JP13356384A
Other languages
Japanese (ja)
Other versions
JPS6112107A (en
Inventor
Kenzo Tsun
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 JP13356384A priority Critical patent/JPS6112107A/en
Publication of JPS6112107A publication Critical patent/JPS6112107A/en
Publication of JPH0325046B2 publication Critical patent/JPH0325046B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H03F1/302—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters in bipolar transistor amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)

Description

【発明の詳細な説明】 (a) 技術分野 この発明はホール素子出力を増幅する入力回路
に関する。DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to an input circuit that amplifies the output of a Hall element.

(b) 従来技術とその欠点 ホール素子１は一般に第２図に示すように電源
端子ａ−ｂ間に加わる電圧をVHとすると、出力
端子ｃに発生する電圧VH／２となる。またホー
ル素子出力を増幅する場合には、その出力端子と
入力回路の初段トランジスタとの結合状態は通
常、直結状態にされる。したがつて、仮に第２図
においてホール素子１に印加される電圧VHを電
源電圧VCCに等しく設定すると、入力初段トラ
ンジスタTR1でホール素子出力を正確に増幅す
るにはVH／２＝VCC／２＞VFにしなければなら
ず、低電圧の電源電圧VCCを使用できない不都
合があつた。即ち、入力回路の電源電圧VCCと
しては、少なくとも2VF以上の電圧が必要であ
り、VF≒0.7V程度であるから1V程度の低い電圧
の電源電圧を使用できない欠点があつた。(b) Prior Art and Its Disadvantages In general, as shown in FIG. 2, in the Hall element 1, when the voltage applied between the power supply terminals a and b is VH , the voltage generated at the output terminal c is VH /2. Further, when the Hall element output is amplified, the coupling state between the output terminal and the first stage transistor of the input circuit is usually made into a direct coupling state. Therefore, if the voltage V H applied to the Hall element 1 in FIG. 2 is set equal to the power supply voltage VCC, in order to accurately amplify the Hall element output with the input first stage transistor TR1, V H /2 = VCC / 2>VF, which had the inconvenience of not being able to use the low power supply voltage VCC. That is, the power supply voltage VCC of the input circuit needs to be at least 2VF or higher, and since VF≈0.7V, a power supply voltage as low as 1V cannot be used.

(c) 発明の目的 この発明の目的は上記の欠点を解消し、ホール
素子出力を簡単な回路でレベルシフトすることに
より電源電圧が低くても動作する入力回路を提供
することにある。(c) Object of the Invention An object of the invention is to eliminate the above-mentioned drawbacks and to provide an input circuit that operates even at a low power supply voltage by level-shifting the Hall element output using a simple circuit.

(d) 発明の構成 この発明は要約すれば、電源電圧を抵抗分割す
る回路と、その分割した電圧を電流変換する回路
と、さらにその変換した電流を抵抗によつて電圧
変換し、その変換電圧をホール素子出力に加えて
レベルシフトする回路とを設けたことを特徴と
し、 抵抗比によつてホール素子出力をVH／２以下
にレベルシフトし、電源電圧が2VF以下でも入力
回路が動作するようにしたものである。(d) Structure of the Invention In summary, the present invention includes a circuit that divides a power supply voltage with resistance, a circuit that converts the divided voltage into a current, and a circuit that converts the converted current into a voltage using a resistor. is added to the Hall element output and a level-shift circuit is provided.The Hall element output is level-shifted to V H /2 or less depending on the resistance ratio, and the input circuit operates even when the power supply voltage is 2VF or less. This is how it was done.

(e) 実施例 第１図はこの発明の実施例である入力回路の回
路図である。(e) Embodiment FIG. 1 is a circuit diagram of an input circuit which is an embodiment of the present invention.

図において、ホール素子１の電源端子ａ，ｂに
は、電圧VHが印加され、また電圧VHは抵抗R1，
R2からなる抵抗分割回路によつて電圧VAに分割
される。分割された電圧VAはトランジスタTR2
に入力する。トランジスタTR2〜TR8および抵
抗R3は電圧VAを電流IOに変換する電流変換回路
を構成するる。この電流変換回路においてトラン
ジスタTR2は電圧VAをエミツタホロアで受け、
トランジスタTR3〜TR8はトランジスタTR7の
ベース電圧VBが上記電圧VAに一致するよう動作
する差動アンプを構成している。電流IOはこの電
圧VBを抵抗R3の両端に発生させることにより形
成している。この電流変換回路によつて電流IOは IO＝VH×R2／（R1＋R2）×R3 ……(1) となる。 In the figure, a voltage V H is applied to the power supply terminals a and b of the Hall element 1, and the voltage V H is applied to the resistors R 1 ,
It is divided into a voltage V A by a resistive divider circuit consisting of R 2 . The divided voltage V A is applied to transistor TR2
Enter. Transistors TR2 to TR8 and resistor R3 constitute a current conversion circuit that converts voltage V A to current I O. In this current conversion circuit, transistor TR2 receives voltage V A at its emitter follower,
The transistors TR3 to TR8 constitute a differential amplifier that operates so that the base voltage V B of the transistor TR7 matches the voltage VA . The current I O is generated by generating this voltage V B across the resistor R 3 . Due to this current conversion circuit, the current I O becomes I O =V H ×R 2 /(R 1 +R 2 ) × R 3 (1).

トランジスタTR8〜TR11は共通ベース接続さ
れ、各トランジスタのエミツタ領域も同面積に設
定されている。このため、トランジスタTR8に
電流IOが流れると、トランジスタTR9に同じ大き
さの電流IO′が流れ、さらにダイオードに接続さ
れたトランジスタTR10、トランジスタTR12に
よつて反転された電流IO″がトランジスタTR11を
流れる。電流IO″は抵抗R4を流れ、この両端に電
圧VCを形成する。抵抗R4とトランジスタTR11の
接続点ｄにはホール素子１の出力端子ｃが接続さ
れている。トランジスタTR9〜TR12および抵抗
R4は出力電圧変換回路を構成する。 The transistors TR8 to TR11 are connected to a common base, and the emitter regions of each transistor are also set to have the same area. Therefore, when current I O flows through transistor TR8, a current I O ′ of the same magnitude flows through transistor TR9, and the current I O ″, which is inverted by transistor TR10 and transistor TR12 connected to the diode, flows through transistor TR9. The current I O ″ flows through the resistor R 4 and forms a voltage V C across it. The output terminal c of the Hall element 1 is connected to the connection point d between the resistor R4 and the transistor TR11. Transistors TR9 to TR12 and resistors
R4 constitutes an output voltage conversion circuit.

以上の構成によつて抵抗R4の両端に発生する
電圧VCは VC＝IO″×R4 ＝IO×R4 ＝VH×R2×R4／（R1＋R2）×R3 ……(2) となる。また増幅部の初段トランジスタTR13の
入力電圧VINは VIN＝VH／２−VC ……(3) となる。 The voltage V C generated across the resistor R 4 with the above configuration is V C = I O ″×R 4 = I O × R 4 = V H × R 2 × R 4 / (R 1 + R 2 )× R 3 ...(2) The input voltage V IN of the first stage transistor TR13 of the amplifier section is V IN =V H /2-V C ...(3).

上記(2)，(3)式から明らかなように電圧VCは抵
抗比率によつて一義的に定まり、この値をホール
素子電圧から引いた電圧が初段トランジスタの入
力電圧となる。したがつて、増幅部に必要な電源
電圧VCCは VCC≧VF＋VIN となり、上記(2)式の抵抗比率を適当に定めること
により、入力回路を動作させるのに必要な電源電
圧VCCをVF〜2VFの間、例えば1Vに設定するこ
とができる。 As is clear from the above equations (2) and (3), the voltage V C is uniquely determined by the resistance ratio, and the voltage obtained by subtracting this value from the Hall element voltage becomes the input voltage of the first stage transistor. Therefore, the power supply voltage VCC required for the amplifier section is VCC≧VF+V IN , and by appropriately determining the resistance ratio in equation (2) above, the power supply voltage VCC required to operate the input circuit can be set to VF~2VF. For example, it can be set to 1V.

(f) 発明の効果 以上のようにこの発明によれば、入力回路を作
動させるための電源電圧VCCを2VF以下に設定
することができるため、電源電圧が低電圧の電子
機器にも組み込むことができる。また抵抗分割回
路，電流変換回路，電圧変換回路等は簡単な回路
の組合せによつて構成できるため、回路構成も複
雑化しない利点がある。(f) Effects of the Invention As described above, according to the present invention, the power supply voltage VCC for operating the input circuit can be set to 2VF or less, so it can be incorporated into electronic equipment with a low power supply voltage. can. Further, since the resistance divider circuit, current conversion circuit, voltage conversion circuit, etc. can be constructed by a combination of simple circuits, there is an advantage that the circuit configuration does not become complicated.

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

第１図はこの発明の実施例である入力回路の回
路図を示し、第２図は従来の入力回路の初段トラ
ンジスタとホール素子の結合部を示す図である。 １…ホール素子。 FIG. 1 shows a circuit diagram of an input circuit according to an embodiment of the present invention, and FIG. 2 shows a coupling portion between a first-stage transistor and a Hall element of a conventional input circuit. 1...Hall element.

Claims (1)

【特許請求の範囲】[Claims] １ 電源電圧を抵抗分割する抵抗分割回路と、そ
の分割した電圧を電流変換する電流変換回路と、
その変換した電流を抵抗によつて電圧変換しその
変換電圧をホール素子出力に加えてホール素子出
力をレベルシフトする出力電圧変換回路とを備え
てなるホール素子の入力回路。1. A resistance divider circuit that divides the power supply voltage by resistance, and a current conversion circuit that converts the divided voltage into a current.
An input circuit for a Hall element, comprising an output voltage conversion circuit that converts the converted current into a voltage using a resistor, adds the converted voltage to the Hall element output, and level-shifts the Hall element output.
JP13356384A 1984-06-27 1984-06-27 Input circuit of hall element Granted JPS6112107A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13356384A JPS6112107A (en) 1984-06-27 1984-06-27 Input circuit of hall element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13356384A JPS6112107A (en) 1984-06-27 1984-06-27 Input circuit of hall element

Publications (2)

Publication Number Publication Date
JPS6112107A JPS6112107A (en) 1986-01-20
JPH0325046B2 true JPH0325046B2 (en) 1991-04-04

Family

ID=15107725

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13356384A Granted JPS6112107A (en) 1984-06-27 1984-06-27 Input circuit of hall element

Country Status (1)

Country Link
JP (1) JPS6112107A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2822558B2 (en) * 1990-03-23 1998-11-11 三菱電機株式会社 Liquid crystal display device and method of manufacturing the same

Also Published As

Publication number Publication date
JPS6112107A (en) 1986-01-20

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