JPH07147727A - Surge voltage protective circuit - Google Patents
Surge voltage protective circuitInfo
- Publication number
- JPH07147727A JPH07147727A JP29301493A JP29301493A JPH07147727A JP H07147727 A JPH07147727 A JP H07147727A JP 29301493 A JP29301493 A JP 29301493A JP 29301493 A JP29301493 A JP 29301493A JP H07147727 A JPH07147727 A JP H07147727A
- Authority
- JP
- Japan
- Prior art keywords
- surge voltage
- power supply
- integrated circuit
- circuit
- zener 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
- Emergency Protection Circuit Devices (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、自動車用計器などの電
子機器に使用される集積回路を、サージ電圧から保護す
るサージ電圧保護回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surge voltage protection circuit for protecting an integrated circuit used in an electronic device such as an automobile instrument from a surge voltage.
【０００２】[0002]
【従来の技術】例えば、自動車の速度計などに使用され
る交差コイル式計器の制御回路は、電源であるバッテリ
ーから電力供給を受けて作動するが、走行時などにおけ
るダイナモからの充電中に、バッテリー端子が外れた場
合、その電源線にサージ電圧が発生し、集積回路を使用
した計器の制御回路が、そのサージ電圧により破壊され
る恐れがあった。2. Description of the Related Art For example, a control circuit of a cross-coil type instrument used for a speedometer of an automobile operates by receiving electric power from a battery which is a power source, but during charging from a dynamo during traveling, When the battery terminal comes off, a surge voltage is generated in the power supply line, and the control circuit of the instrument using the integrated circuit may be damaged by the surge voltage.
【０００３】[0003]
【発明が解決しようとする課題】このため、従来、図４
に示すように、集積回路２０に接続される電源線２１に
抵抗Ｒｓを直列に接続すると共に、その電源線２１とグ
ランド間にツェナーダイオードＺＤを接続し、サージ電
圧を吸収して集積回路２０の破壊を防止する保護回路が
使用されている（例えば、実開昭６２−１７８３７５号
公報等参照）。For this reason, as shown in FIG.
As shown in FIG. 3, a resistor Rs is connected in series to the power supply line 21 connected to the integrated circuit 20, and a Zener diode ZD is connected between the power supply line 21 and the ground to absorb the surge voltage and absorb the surge voltage. A protection circuit for preventing destruction is used (see, for example, Japanese Utility Model Laid-Open No. 62-178375).
【０００４】しかし、このようなサージ電圧吸収用のツ
ェナーダイオードＺＤを外付けした保護回路は、必然的
に形状が大形化すると共に、部品点数が増し、製造コス
トも高くなる問題があった。However, such a protection circuit to which the Zener diode ZD for absorbing surge voltage is externally attached inevitably has a problem that the size is increased, the number of parts is increased, and the manufacturing cost is increased.
【０００５】本発明は、上記の点に鑑みてなされたもの
で、小形化が実現でき、製造コストの削減も可能な集積
回路を保護するサージ電圧保護回路を提供することを目
的とする。The present invention has been made in view of the above points, and an object of the present invention is to provide a surge voltage protection circuit for protecting an integrated circuit which can be miniaturized and can be manufactured at a reduced cost.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
に、本発明のサージ電圧保護回路は、集積回路の電源線
に生じたサージ電圧から集積回路を保護するサージ電圧
保護回路において、集積回路内にサージ電圧吸収用のツ
ェナーダイオードが内蔵され、電源線に接続される集積
回路の端子とグランド端子間にツェナーダイオードが接
続されて構成される。In order to achieve the above object, a surge voltage protection circuit of the present invention is a surge voltage protection circuit for protecting an integrated circuit from a surge voltage generated in a power supply line of the integrated circuit. A zener diode for absorbing surge voltage is built in the device, and the zener diode is connected between the terminal of the integrated circuit connected to the power supply line and the ground terminal.
【０００７】[0007]
【作用・効果】このような構成のサージ電圧保護回路で
は、電源線にサージ電圧が発生した場合、ツェナーダイ
オードによりそのサージ電圧が吸収され、集積回路内の
内蔵回路にサージ電圧が印加されることを阻止し、サー
ジ電圧による内蔵回路の破壊を防止することができる。[Operation and effect] In the surge voltage protection circuit having such a configuration, when a surge voltage occurs in the power supply line, the Zener diode absorbs the surge voltage and the surge voltage is applied to the internal circuit in the integrated circuit. It is possible to prevent the internal circuit from being damaged by surge voltage.
【０００８】また、サージ電圧吸収用のツェナーダイオ
ードが集積回路に内蔵されているため、従来のようにツ
ェナーダイオードを外付けする必要がなく、実質的な回
路の形状を小形化できると共に、部品点数を削減でき、
製造コストも低減することができる。Further, since the Zener diode for absorbing the surge voltage is built in the integrated circuit, it is not necessary to externally attach the Zener diode as in the conventional case, and the substantial circuit shape can be made small and the number of parts can be reduced. Can be reduced
Manufacturing costs can also be reduced.
【０００９】[0009]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【００１０】図１は、自動車用速度計の制御回路におけ
るサージ電圧保護回路を示している。この制御回路は、
集積回路１を主要部にして構成され、集積回路１には、
車速センサ等から送られた車速信号Ｇｓを入力して電圧
に変換するＦ−Ｖ変換器１１、Ｆ−Ｖ変換器１１からの
出力信号に応じて速度計の交差コイル２に電流を供給す
る駆動回路１２等が内蔵される。さらに、この集積回路
１には、サージ電圧吸収用のツェナーダイオードＺＤが
内蔵されている。FIG. 1 shows a surge voltage protection circuit in a control circuit of an automobile speedometer. This control circuit
The integrated circuit 1 is configured with a main part, and the integrated circuit 1 includes
FV converter 11 for inputting a vehicle speed signal Gs sent from a vehicle speed sensor or the like, and driving for supplying current to the cross coil 2 of the speedometer according to an output signal from the FV converter 11 The circuit 12 and the like are incorporated. Further, the integrated circuit 1 contains a Zener diode ZD for absorbing surge voltage.
【００１１】１３は集積回路１の電源入力端子であり、
この電源入力端子１３には抵抗Ｒ１を直列接続した電源
線３が接続される。また、１４は電源線３に接続される
補助端子であり、集積回路１内で、ツェナーダイオード
ＺＤのカソード側がこの補助端子１４に接続され、補助
端子１４の外側には、電源線３が抵抗Ｒ２を介して接続
される。Reference numeral 13 denotes a power source input terminal of the integrated circuit 1,
A power supply line 3 having a resistor R1 connected in series is connected to the power supply input terminal 13. Further, 14 is an auxiliary terminal connected to the power supply line 3, the cathode side of the Zener diode ZD is connected to this auxiliary terminal 14 in the integrated circuit 1, and the power supply line 3 is connected to the resistor R2 outside the auxiliary terminal 14. Connected via.
【００１２】一方、ツェナーダイオードＺＤのアノード
側はグランド端子１５に接続される。また、電源線３は
自動車に搭載された電源用のバッテリー（図示せず）に
接続される。On the other hand, the anode side of the Zener diode ZD is connected to the ground terminal 15. The power supply line 3 is connected to a battery (not shown) for power supply mounted on the automobile.
【００１３】このように構成された速度計の制御回路で
は、集積回路１が、電源線３から電源入力端子１３を通
して定電圧電源の供給を受けて動作し、車速センサから
車速に応じた周波数の車速信号ＧＳが集積回路１内のＦ
−Ｖ変換器１１に入力され、車速に応じた電圧信号が駆
動回路１２に送られ、駆動回路１２は速度計の一対の交
差コイル２に車速に応じた電流を出力し、速度計の指針
を回動させてその速度を指示する。In the speedometer control circuit configured as described above, the integrated circuit 1 operates by receiving a constant voltage power supply from the power supply line 3 through the power supply input terminal 13, and operates at a frequency corresponding to the vehicle speed from the vehicle speed sensor. The vehicle speed signal GS is F in the integrated circuit 1.
The voltage signal corresponding to the vehicle speed is input to the -V converter 11, and the voltage signal corresponding to the vehicle speed is sent to the drive circuit 12. The drive circuit 12 outputs a current corresponding to the vehicle speed to the pair of crossing coils 2 of the speedometer, and the pointer of the speedometer is displayed. Rotate to indicate the speed.
【００１４】このような動作中、電源線３が接続された
バッテリーの端子が外れた場合、特にダイナモによる充
電時には、電源線３にサージ電圧が発生する。このサー
ジ電圧は、図２に示すように、ピーク値が約７０Ｖに達
し、集積回路１の耐圧は約３５Ｖ程度であるため、この
サージ電圧が電源入力端子１３を通して回路内に印加さ
れた場合には、回路が破壊され恐れがある。During such operation, when the terminal of the battery to which the power supply line 3 is connected is disconnected, a surge voltage is generated on the power supply line 3 especially during charging by a dynamo. As shown in FIG. 2, the surge voltage has a peak value of about 70 V and the withstand voltage of the integrated circuit 1 is about 35 V. Therefore, when the surge voltage is applied to the circuit through the power input terminal 13, May damage the circuit.
【００１５】しかし、電源線３にはサージ電圧吸収用の
ツェナーダイオードＺＤが接続されているため、サージ
電圧の発生時、サージ電圧がツェナーダイオードＺＤに
逆方向電圧として印加されると、ツェナーダイオードＺ
Ｄはブレイクダウンを起して逆方向電流が急激に増加
し、その印加電圧を所定のツェナー電圧に抑制するよう
に動作する。このため、電源線３からのサージ電圧が電
源入力端子１３を介して内蔵回路に印加されることが阻
止され、内蔵回路のサージ電圧による破壊は防止され
る。However, since a zener diode ZD for absorbing a surge voltage is connected to the power supply line 3, if a surge voltage is applied as a reverse voltage to the zener diode ZD when a surge voltage occurs, the zener diode ZD is applied.
D causes a breakdown and the reverse current abruptly increases, and operates so as to suppress the applied voltage to a predetermined Zener voltage. Therefore, the surge voltage from the power supply line 3 is prevented from being applied to the built-in circuit through the power supply input terminal 13, and the built-in circuit is prevented from being damaged by the surge voltage.
【００１６】また、この時、電源線３からツェナーダイ
オードＺＤに流れ込む電流は、端子１４と電源線３との
間に接続された抵抗２によって抑制されるため、ツェナ
ーダイオードＺＤの発熱を抑制すると共に、その破壊を
防止することができる。At this time, the current flowing from the power supply line 3 to the Zener diode ZD is suppressed by the resistor 2 connected between the terminal 14 and the power supply line 3, so that heat generation of the Zener diode ZD is suppressed. , Its destruction can be prevented.
【００１７】なお、上記実施例では、速度計の制御回路
となる集積回路のサージ電圧保護回路について説明した
が、その他の電子機器の集積回路についても、上記と同
様にサージ電圧保護回路を構成することができる。In the above embodiment, the surge voltage protection circuit of the integrated circuit which serves as the control circuit of the speedometer has been described, but the integrated circuits of other electronic devices also have the surge voltage protection circuit similarly to the above. be able to.
【００１８】図３は他の実施例を示し、１６は電子機器
の制御回路に使用される集積回路であり、集積回路１６
にもサージ電圧吸収用のツェナーダイオードＺＤが内蔵
される。このツェナーダイオードＺＤのカソード側は内
側から電源入力端子１７に接続され、ツェナーダイオー
ドＺＤのアノード側はダイオードＤを介してグランド端
子１９に接続される。FIG. 3 shows another embodiment, and 16 is an integrated circuit used for a control circuit of electronic equipment.
Also, a Zener diode ZD for absorbing surge voltage is built in. The cathode side of the Zener diode ZD is connected from inside to the power supply input terminal 17, and the anode side of the Zener diode ZD is connected to the ground terminal 19 via the diode D.
【００１９】このダイオードＤは、上記実施例に使用し
た抵抗Ｒ２の代わりに使用され、サージ電圧の印加時に
ツェナーダイオードＺＤに流れる電流を抑制する。電源
入力端子１７の外側には、抵抗Ｒ１を直列接続した電源
線３が接続される。また、電源入力端子１７の内側は集
積回路１６内の内蔵回路１８に電源ラインとして接続さ
れ、その電源入力端子１７を通して定電圧電源の供給を
受ける。This diode D is used in place of the resistor R2 used in the above embodiment, and suppresses the current flowing through the Zener diode ZD when a surge voltage is applied. A power supply line 3 in which a resistor R1 is connected in series is connected to the outside of the power supply input terminal 17. Further, the inside of the power supply input terminal 17 is connected as a power supply line to a built-in circuit 18 in the integrated circuit 16, and a constant voltage power supply is supplied through the power supply input terminal 17.
【００２０】このように構成されたサージ電圧保護回路
においても、上記実施例を同様に、電源線３にサージ電
圧が発生した際、サージ電圧はツェナーダイオードＺＤ
によって吸収され、内蔵回路１８のサージ電圧による破
壊は防止される。Also in the surge voltage protection circuit configured as described above, when a surge voltage is generated in the power supply line 3, the surge voltage is generated by the Zener diode ZD as in the above embodiment.
The internal circuit 18 is prevented from being damaged by the surge voltage.
【図１】本発明の一実施例を示す速度計の制御回路にお
けるサージ電圧保護回路の回路図である。FIG. 1 is a circuit diagram of a surge voltage protection circuit in a speedometer control circuit according to an embodiment of the present invention.
【図２】サージ電圧の電圧波形図である。FIG. 2 is a voltage waveform diagram of a surge voltage.
【図３】他の実施例のサージ電圧保護回路の回路図であ
る。FIG. 3 is a circuit diagram of a surge voltage protection circuit according to another embodiment.
【図４】従来のサージ電圧保護回路である。FIG. 4 is a conventional surge voltage protection circuit.
１−集積回路、３−電源線、Ｒ１、Ｒ２−抵抗、ＺＤ−
ツェナーダイオード、１３−電源入力端子、１４−補助
端子、１５−グランド端子。1-integrated circuit, 3-power line, R1, R2-resistor, ZD-
Zener diode, 13-power input terminal, 14-auxiliary terminal, 15-ground terminal.
Claims (1)
ら該集積回路を保護するサージ電圧保護回路において、 該集積回路内にサージ電圧吸収用のツェナーダイオード
が内蔵され、前記電源線に接続される集積回路の端子と
グランド端子間に該ツェナーダイオードが接続されてい
ることを特徴とするサージ電圧保護回路。1. A surge voltage protection circuit for protecting an integrated circuit from a surge voltage generated in a power supply line of the integrated circuit, wherein a zener diode for absorbing surge voltage is built in the integrated circuit and connected to the power supply line. A surge voltage protection circuit, wherein the Zener diode is connected between a terminal of the integrated circuit and a ground terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29301493A JPH07147727A (en) | 1993-11-24 | 1993-11-24 | Surge voltage protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29301493A JPH07147727A (en) | 1993-11-24 | 1993-11-24 | Surge voltage protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07147727A true JPH07147727A (en) | 1995-06-06 |
Family
ID=17789366
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29301493A Pending JPH07147727A (en) | 1993-11-24 | 1993-11-24 | Surge voltage protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07147727A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001160498A (en) * | 1999-12-01 | 2001-06-12 | Sony Corp | Charging semiconductor device |
| SG128495A1 (en) * | 2005-06-09 | 2007-01-30 | Chih-Yang Su | Voltage stabilizing and surge preventing vehicle grounding system |
| JP2007244147A (en) * | 2006-03-10 | 2007-09-20 | Hitachi Ltd | Power source protective circuit for integrated circuit |
| WO2007111395A1 (en) * | 2006-03-29 | 2007-10-04 | Saturn Information & Communication Corp. | Circuits breaker having resetting function and breaking function for abnormal current |
| US7564101B2 (en) | 2004-09-14 | 2009-07-21 | Denso Corporation | Semiconductor device for protecting a circuit formed on a semiconductor chip from destruction caused by an electrostatic discharge |
| JP2020184101A (en) * | 2019-04-26 | 2020-11-12 | ローム株式会社 | Linear regulator and semiconductor integrated circuit |
-
1993
- 1993-11-24 JP JP29301493A patent/JPH07147727A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001160498A (en) * | 1999-12-01 | 2001-06-12 | Sony Corp | Charging semiconductor device |
| US7564101B2 (en) | 2004-09-14 | 2009-07-21 | Denso Corporation | Semiconductor device for protecting a circuit formed on a semiconductor chip from destruction caused by an electrostatic discharge |
| SG128495A1 (en) * | 2005-06-09 | 2007-01-30 | Chih-Yang Su | Voltage stabilizing and surge preventing vehicle grounding system |
| JP2007244147A (en) * | 2006-03-10 | 2007-09-20 | Hitachi Ltd | Power source protective circuit for integrated circuit |
| US7656624B2 (en) | 2006-03-10 | 2010-02-02 | Hitachi, Ltd. | IC power protection circuit |
| JP4690915B2 (en) * | 2006-03-10 | 2011-06-01 | 日立オートモティブシステムズ株式会社 | Integrated circuit power protection circuit |
| WO2007111395A1 (en) * | 2006-03-29 | 2007-10-04 | Saturn Information & Communication Corp. | Circuits breaker having resetting function and breaking function for abnormal current |
| JP2020184101A (en) * | 2019-04-26 | 2020-11-12 | ローム株式会社 | Linear regulator and semiconductor integrated circuit |
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