JPS63114317A - Switching element drive circuit - Google Patents
Switching element drive circuitInfo
- Publication number
- JPS63114317A JPS63114317A JP25927186A JP25927186A JPS63114317A JP S63114317 A JPS63114317 A JP S63114317A JP 25927186 A JP25927186 A JP 25927186A JP 25927186 A JP25927186 A JP 25927186A JP S63114317 A JPS63114317 A JP S63114317A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- power supply
- drive circuit
- switch element
- positive
- 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
Links
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 230000003321 amplification Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔概要〕
演算増幅器（今の場合比較器）を用いたトランジスタ駆
動回路において、該演算増幅器の正極側電源電圧として
出力に現れるオフセット電圧の絶対値よりも大きく、か
つ逆極性の電圧を与えることにより、該オフセット電圧
によるトランジスタのオン／オフ動作への影響をなくし
、入力信号に対応してトランジスタを確実にオン／オフ
動作させるようにするものである。[Detailed Description of the Invention] [Summary] In a transistor drive circuit using an operational amplifier (in this case, a comparator), an offset voltage that is larger than the absolute value of the offset voltage that appears at the output as the positive power supply voltage of the operational amplifier, and is opposite to the By applying a polar voltage, the effect of the offset voltage on the on/off operation of the transistor is eliminated, and the transistor is reliably turned on/off in response to the input signal.
本発明は、ディジタル交換機の加入者回路に使用される
スイッチ回路としてのスイッチ素子駆動回路の改良に関
するものである。The present invention relates to an improvement of a switch element drive circuit as a switch circuit used in a subscriber circuit of a digital exchange.
加入者回路には、加入者の電話機のオン・フック／オフ
・フックを検出するため、該オン・フック／オフ・フッ
クに対応した直流ループを検出してオン／オフ動作を行
うスイッチ回路を、監視回路として設けている。そして
交換機内のソフトウエア部で、加入者からの通話をする
ためのオフ・フックによる“Ｏ”又は“１”の信号を受
けてダイヤル信号を受信する準備をするが、オン／オフ
のスイッチ動作が正確に行われていないと、オフ・フッ
クによる信号が受けられず、ダイヤル信号を受信する準
備が出来ず、通話が出来ないことになる。In order to detect on-hook/off-hook of the subscriber's telephone, the subscriber circuit includes a switch circuit that detects a DC loop corresponding to the on-hook/off-hook and performs on/off operation. It is provided as a monitoring circuit. The software inside the exchange prepares to receive a dial signal by receiving an off-hook signal of "O" or "1" for making a call from the subscriber, but the on/off switch operation If this is not done correctly, the off-hook signal will not be received, the dialing signal will not be ready to be received, and the call will not be possible.
このためオン／オフのスイッチ動作は正確に行われるこ
とが望ましい。Therefore, it is desirable that the on/off switch operation be performed accurately.
第３図は従来例のトランジスタ駆動回路図である。 FIG. 3 is a diagram of a conventional transistor drive circuit.
第３図において、比較器１′の出力を、抵抗Ｒを介して
ＰＮＰ トランジスタ（以下ｐ ｎ ｐ Ｔｒと称する
）２′のベースに印加する。In FIG. 3, the output of the comparator 1' is applied via a resistor R to the base of a PNP transistor (hereinafter referred to as p n p Tr) 2'.
比較器１′は正、負２つの入力端子を有し、例えば正の
入力端子には基準電圧ｖｔｈを、負の入力端子には入力
信号電圧を加える。入力信号電圧が基準電圧Ｖｔｈ（例
えば−２０ｖ）より大の時、電源電圧■の負の電圧（−
Ｖｂｂ、例えば−２４ｖ）が比較器１′から出力され、
ｐｎｐＴｒ ２’のベースの電圧が負となってｐｎｐＴ
ｒ ２’は順バイアス状態となりオンになって、負荷３
に電流が流れる。The comparator 1' has two input terminals, a positive input terminal and a negative input terminal. For example, a reference voltage vth is applied to the positive input terminal, and an input signal voltage is applied to the negative input terminal. When the input signal voltage is higher than the reference voltage Vth (for example -20V), the negative voltage (-
Vbb, e.g. -24v) is output from comparator 1',
The voltage at the base of pnpTr 2' becomes negative and pnpT
r2' becomes forward biased and turns on, causing load 3
A current flows through.
一方、入力信号電圧が基準電圧ｖｔｈよりも小の時、電
源電圧■のアースの電圧が比較器１′から出力され、ｐ
ｎｐＴｒ ２’は逆バイアス状態となりオフになって、
負荷３に電流が流れなくなる。On the other hand, when the input signal voltage is smaller than the reference voltage vth, the ground voltage of the power supply voltage ■ is output from the comparator 1', and p
npTr 2' becomes reverse biased and turns off,
Current no longer flows to load 3.
このようにして比較器１′の出力電圧により、ｐｎｐＴ
ｒ２’をオン／オフしてスイッチ動作させていた。In this way, the output voltage of comparator 1' allows pnpT
The switch was operated by turning r2' on and off.
尚、比較器１′の出力端子とｐｎｐＴｒ２’のベースの
間に抵抗Ｒを挿入しているのは、ｐ ｎ ｐ Ｔｒ２′
がオンの時、ｐｎｐＴｒ２′のベースを通って比較器１
′に流れ込む電流を制限するためである。Note that the resistor R is inserted between the output terminal of comparator 1' and the base of pnpTr2'.
is on, comparator 1 passes through the base of pnpTr2'
This is to limit the current flowing into .
しかしながら上述のトランジスタ駆動回路においては、
比較器１′の出力にオフセット電圧（負極性）が生じる
ことがあり、入力の信号電圧が基準電圧より小の時でも
オフセット電圧と、ｐｎｐＴｒ２’のベース・エミッタ
間電圧（Ｖｂｅ）の差の電圧が、抵抗Ｒの両端に発生し
、微少なベース電流（Ｉｂ ）が流れるため、ｐｎｐＴ
ｒ２’の電流増幅率ｈＦＥが大きい時、ｐｎｐＴｒ２’
のコレクタに流れる電流Ｉｃ （Ｉｃ ＝ｈＦＨＸ
Ｉｂと表される）が、無視できなくなる程大きくなる可
能性がある。However, in the above transistor drive circuit,
An offset voltage (negative polarity) may occur in the output of comparator 1', and even when the input signal voltage is lower than the reference voltage, the voltage difference between the offset voltage and the base-emitter voltage (Vbe) of pnpTr2' occurs across the resistor R, and a small base current (Ib) flows, so that the pnpT
When the current amplification factor hFE of r2' is large, pnpTr2'
The current Ic flowing through the collector of (Ic =hFHX
(denoted as Ib) may become so large that it cannot be ignored.
このためｐｎｐＴｒ２’はオンとなり、負荷に電流が流
れるという問題点があった。Therefore, there was a problem in that pnpTr2' was turned on and current flowed to the load.
上記問題点は第１図に示すように、二つの入力端子と、
二つの電源電圧印加端子を有し、一方の入力端子に基準
電圧を加え、他方の入力端子に入力信号を加え、第一の
電源電圧印加端子に０■、又は正の電圧を加え、第二の
電源電圧印加端子に負の電圧を加えた演算増幅器１の出
力電圧により、スイッチ素子２を駆動して、該スイッチ
素子２にオン／オフのスイッチ動作を行わせるスイッチ
素子駆動回路において、該第一の電源電圧印加端子に、
絶対値において該演算増幅器ｌの出力に現れるオフセッ
ト電圧値を越え、かつ該オフセット電圧と逆極性の電圧
を与える本発明のスイッチ素子駆動回路によって解決さ
れる。The above problem is caused by two input terminals and
It has two power supply voltage application terminals, applies a reference voltage to one input terminal, applies an input signal to the other input terminal, applies 0 or positive voltage to the first power supply voltage application terminal, and In the switch element driving circuit, the switch element 2 is driven by the output voltage of the operational amplifier 1, which is applied with a negative voltage to the power supply voltage application terminal of the switch element 2, and the switch element 2 performs an on/off switching operation. To the first power supply voltage application terminal,
This problem is solved by the switch element drive circuit of the present invention which provides a voltage that exceeds the offset voltage value appearing at the output of the operational amplifier l in absolute value and has a polarity opposite to the offset voltage.
第１図において、第一の電源電圧としてオフセット電圧
の絶対値を越え、かつオフセット電圧と逆極性の電圧を
与えることにより、入力信号電圧が基準電圧より小の時
、スイッチ素子２の入力はＯｖ又は正極性となりスイッ
チ素子２はオフになって、負荷に電流が流れないように
することが出来る。In FIG. 1, by applying a voltage that exceeds the absolute value of the offset voltage and has a polarity opposite to the offset voltage as the first power supply voltage, when the input signal voltage is smaller than the reference voltage, the input of the switching element 2 is Ov. Alternatively, the polarity becomes positive and the switch element 2 is turned off, so that no current flows to the load.
第２図は本発明の実施例のトランジスタ駆動回路図であ
る。FIG. 2 is a transistor drive circuit diagram of an embodiment of the present invention.
全図を通じて同一符号は同一対象物を示す。The same reference numerals indicate the same objects throughout the figures.
第２図において、比較器１′の電源電圧■として、アー
スの電位の代わりにオフセット電圧（負極性、例えば−
０，７Ｖ〜−１，５Ｖ）の絶対値を越える正極性の電圧
（＋ＶＣＣ％例えば５Ｖ）を与えることにより、入力信
号電圧が基準電圧ｖｔｈより小の時、ｐｎｐＴｒ ２’
のベースは０■又は正の電圧となり、ｐｎｐＴｒ ２’
は逆バイアス状態となりオフとなって、負荷３に電流が
流れることはない。In FIG. 2, as the power supply voltage (■) of the comparator 1', an offset voltage (negative polarity, for example -
By applying a positive voltage (+VCC%, for example, 5V) exceeding the absolute value of 0.7V to -1.5V, when the input signal voltage is smaller than the reference voltage vth, pnpTr 2'
The base of becomes 0■ or positive voltage, pnpTr 2'
is in a reverse bias state and turned off, and no current flows through the load 3.
以上説明のように本発明のスイッチ素子駆動回路によれ
ば、演算増幅器の正極側電源電圧として出力に現れるオ
フセット電圧の絶対値を越え、かつ該オフセット電圧と
逆極性の電圧を与えることにより、トランジスタのオン
／オフのスイッチ動作を確実に行わせることが出来る。As described above, according to the switch element drive circuit of the present invention, by applying a voltage that exceeds the absolute value of the offset voltage appearing at the output as the positive power supply voltage of the operational amplifier and has a polarity opposite to the offset voltage, The on/off switch operation can be performed reliably.
第１図は本発明の原理図、
第２図は本発明の実施例のトランジスタ駆動回路図、
第３図は従来例のトランジスタ駆動回路図である。
図において
１は演算増幅器、自ま比較器、
２はスイッチ素子、２′はｐｎｐＴｒ、３は負荷、
を示す。
Ｖ工
木発−−室記イダ膣Ｆフンシヌタ馬Ｅ動ロヱを２第 ２
図
ｚ
徒子金１のトランジスタ１．うＥ勲団発図玉３ 図FIG. 1 is a principle diagram of the present invention, FIG. 2 is a transistor drive circuit diagram of an embodiment of the present invention, and FIG. 3 is a transistor drive circuit diagram of a conventional example. In the figure, 1 is an operational amplifier, a self-comparator, 2 is a switch element, 2' is a pnpTr, and 3 is a load. V Koki - Muroki Ida Vagina F Funshinuta Horse E Motion Roe 2nd 2nd
Figure z: Transistor 1 with metal 1. E-Order Ball 3 Diagram
Claims (1)
方の入力端子に基準電圧を加え、他方の入力端子に入力
信号を加え、 第一の電源電圧印加端子に０Ｖ、又は正の電圧を加え、
第二の電源電圧印加端子に負の電圧を加えた演算増幅器
（１）の出力電圧により、 スイッチ素子（２）を駆動して、該スイッチ素子（２）
にオン／オフのスイッチ動作を行わせるスイッチ素子駆
動回路において、 該第一の電源電圧印加端子に、絶対値において該演算増
幅器（１）の出力に現れるオフセット電圧値を越え、か
つ該オフセット電圧と逆極性の電圧を与えることを特徴
とするスイッチ素子駆動回路。[Claims] It has two input terminals and two power supply voltage application terminals, a reference voltage is applied to one input terminal, an input signal is applied to the other input terminal, and the first power supply voltage application terminal is Apply 0V or positive voltage,
The switch element (2) is driven by the output voltage of the operational amplifier (1) with a negative voltage applied to the second power supply voltage application terminal, and the switch element (2)
In a switch element drive circuit that performs an on/off switch operation, a voltage is applied to the first power supply voltage application terminal that exceeds, in absolute value, an offset voltage value appearing at the output of the operational amplifier (1) and is equal to the offset voltage. A switch element drive circuit characterized by applying a voltage of opposite polarity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61259271A JP2560701B2 (en) | 1986-10-30 | 1986-10-30 | Switch element drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61259271A JP2560701B2 (en) | 1986-10-30 | 1986-10-30 | Switch element drive circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63114317A true JPS63114317A (en) | 1988-05-19 |
| JP2560701B2 JP2560701B2 (en) | 1996-12-04 |
Family
ID=17331776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61259271A Expired - Fee Related JP2560701B2 (en) | 1986-10-30 | 1986-10-30 | Switch element drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2560701B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6184663B1 (en) | 1998-08-28 | 2001-02-06 | Denso Corporation | Apparatus for driving electric load |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60256222A (en) * | 1984-05-31 | 1985-12-17 | Mitsubishi Electric Corp | Base drive circuit of transistor |
-
1986
- 1986-10-30 JP JP61259271A patent/JP2560701B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60256222A (en) * | 1984-05-31 | 1985-12-17 | Mitsubishi Electric Corp | Base drive circuit of transistor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6184663B1 (en) | 1998-08-28 | 2001-02-06 | Denso Corporation | Apparatus for driving electric load |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2560701B2 (en) | 1996-12-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |