JPH09102735A - IGBT protection circuit - Google Patents
IGBT protection circuitInfo
- Publication number
- JPH09102735A JPH09102735A JP25848995A JP25848995A JPH09102735A JP H09102735 A JPH09102735 A JP H09102735A JP 25848995 A JP25848995 A JP 25848995A JP 25848995 A JP25848995 A JP 25848995A JP H09102735 A JPH09102735 A JP H09102735A
- Authority
- JP
- Japan
- Prior art keywords
- igbt
- circuit
- protection circuit
- current
- 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
- Electronic Switches (AREA)
Abstract
(57)【要約】
【課題】本発明の目的は、保護回路の信頼性を向上する
とともに使い勝ってを良くすることにある。
【解決手段】ＩＧＢＴのコレクタ・エミッタ間電圧を検
出するダイオード５の低圧側に直列に、外部情報によっ
てオン，オフする開閉手段を備えた。
【効果】外部情報によってオン，オフする開閉手段を動
作させることにより過電流保護回路（ソフト遮断回路）
を動作させることができるため、自由な設定レベルでＩ
ＧＢＴを安全にターンオフすることができる。
(57) An object of the present invention is to improve the reliability and the usability of a protection circuit. SOLUTION: An opening / closing means for turning on / off according to external information is provided in series with a low voltage side of a diode 5 for detecting a collector-emitter voltage of an IGBT. [Effect] Overcurrent protection circuit (soft cutoff circuit) by operating the switching means that turns on and off according to external information
Can be operated, I
The GBT can be safely turned off.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ＩＧＢＴのゲート
駆動回路に係り、ＩＧＢＴを特に市販の過電流保護回路
付きゲート駆動回路で駆動する場合あるいは、ディスク
リ−ト部品で同機能を構成して駆動する場合に好適な保
護回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IGBT gate drive circuit, particularly when the IGBT is driven by a commercially available gate drive circuit with an overcurrent protection circuit, or the same function is formed by discrete components. The present invention relates to a protection circuit suitable for driving.
【０００２】[0002]
【従来の技術】従来のＩＧＢＴの保護回路として、ハイ
ブリッドＩＣ等で市販されている過電流保護回路付きゲ
ート駆動回路の例を図３に、また負荷短絡時の波形例を
図４に示す。この図３において、ＩＧＢＴ１および負荷
２の直列回路が直流電源３の両端に接続されており、Ｉ
ＧＢＴ１をオン，オフ制御することによって直流電源３
から負荷２に電力を供給する。2. Description of the Related Art As a conventional IGBT protection circuit, FIG. 3 shows an example of a gate drive circuit with an overcurrent protection circuit which is commercially available as a hybrid IC or the like, and FIG. 4 shows an example of a waveform when a load is short-circuited. In FIG. 3, the series circuit of the IGBT 1 and the load 2 is connected to both ends of the DC power supply 3, and I
DC power supply 3 by controlling on / off of GBT1
Power is supplied to the load 2.
【０００３】ここで、ＩＧＢＴ１をオン，オフ制御する
ために抵抗８，ホトカプラ９からなる入力回路および抵
抗２１，トランジスタ２２，２３，２４，抵抗４からな
る駆動回路が接続されている。さらに、ＩＧＢＴ１のコ
レクタ・エミッタ間電圧を検出するダイオード５、およ
びＩＧＢＴ１のコレクタ・エミッタ間電圧が大きい時す
なわち、負荷２が短絡しＩＧＢＴ１に短絡電流が流れて
いる時にＩＧＢＴ１のゲート・エミッタ間電圧を低下さ
せ、ＩＧＢＴ１をターンオフさせるツェナーダイオード
１２，抵抗１４，トランジスタ１５，抵抗１６，コンデ
ンサ１８，ダイオード１９からなる過電流保護回路（ソ
フト遮断回路）が接続されている。Here, an input circuit including a resistor 8 and a photocoupler 9 and a drive circuit including a resistor 21, transistors 22, 23 and 24, and a resistor 4 are connected in order to turn on and off the IGBT 1. Further, when the diode 5 for detecting the collector-emitter voltage of the IGBT 1 and the collector-emitter voltage of the IGBT 1 are large, that is, when the load 2 is short-circuited and the short-circuit current flows in the IGBT 1, the gate-emitter voltage of the IGBT 1 is changed. An overcurrent protection circuit (soft cutoff circuit) including a Zener diode 12, a resistor 14, a transistor 15, a resistor 16, a capacitor 18, and a diode 19 which lowers and turns off the IGBT 1 is connected.
【０００４】通常時は、入力回路のＶINに正の信号が印
加されるとホトカプラ９の出力側がオンし、トランジス
タ１１，２２，２４がオフ，トランジスタ２３がオンし
てＩＧＢＴ１のゲート・エミッタ間には、抵抗４を介し
てゲート電流が供給されＩＧＢＴ１のゲート・エミッタ
間電圧が上昇し、正電位にバイアスされIGBT1 はターン
オンする。また、この時ＩＧＢＴ１に流れる電流ＩC は
過電流状態でないため、ダイオード５には、直流電源
６，抵抗１０，ＩＧＢＴ１のコレクタ・エミッタ間電
圧、ダイオード５の順電圧で決まる電流が流れており過
電流保護回路は動作しない。Normally, when a positive signal is applied to V IN of the input circuit, the output side of the photocoupler 9 is turned on, the transistors 11, 22 and 24 are turned off, the transistor 23 is turned on, and the gate-emitter of the IGBT 1 is turned on. , A gate current is supplied through the resistor 4, the gate-emitter voltage of the IGBT 1 rises, the bias voltage is biased to a positive potential, and the IGBT 1 turns on. At this time, since the current I C flowing through the IGBT 1 is not in an overcurrent state, a current that is determined by the DC power supply 6, the resistor 10, the collector-emitter voltage of the IGBT 1 and the forward voltage of the diode 5 flows in the diode 5. The current protection circuit does not work.
【０００５】次に、入力回路のＶINの正の信号がなくな
るとホトカプラ９の出力側がオフしトランジスタ１１，
２２，２４がオン，トランジスタ２３がオフし、ＩＧＢ
Ｔ１のゲート・エミッタ間は、抵抗４を介してゲート電
荷が引き抜かれＩＧＢＴ１のゲート・エミッタ間電圧
は、負電位にバイアスされＩＧＢＴ１はターンオフす
る。この時、ダイオード５には電流が流れていない。Next, when the positive signal of V IN of the input circuit disappears, the output side of the photocoupler 9 turns off and the transistors 11,
22 and 24 are turned on, the transistor 23 is turned off, and the IGB
Gate charge is extracted between the gate and emitter of T1 via the resistor 4, the gate-emitter voltage of IGBT1 is biased to a negative potential, and IGBT1 is turned off. At this time, no current is flowing through the diode 5.
【０００６】さらに、入力回路のＶINに正の信号が印加
され、ＩＧＢＴ１がオン状態時に負荷２が短絡した場合
には、ＩＧＢＴ１に流れる電流ＩC が短絡電流となりこ
の電流が飽和電流値に達してからＩＧＢＴ１のコレクタ
・エミッタ間電圧が急激に上昇し、ダイオード５には電
流が流れなくなりツェナーダイオード１２，トランジス
タ１５がオンし、抵抗４，トランジスタ２３のエミッタ
・ベース間を介してＩＧＢＴ１のゲート電荷が引き抜か
れＩＧＢＴ１のゲート・エミッタ間電圧は、抵抗１６，
コンデンサ１８で決まるスロープ（ソフト遮断）で低下
しＩＧＢＴ１はターンオフする。ここで、ＩＧＢＴ１の
コレクタ・エミッタ間電圧の検出レベルは、ツェナーダ
イオード１２，直流電源６，７の設定値で決まり、一般
的には、通常のオン，オフで誤動作しないレベルとして
いる。そのため短絡電流が大きくなり、ソフト遮断して
いるにもかかわらず急俊な−ｄｉ／ｄｔによる跳上り電
圧（ΔＶCE）により，最悪ＩＧＢＴ１が破壊に至ること
があった。Further, when a positive signal is applied to V IN of the input circuit and the load 2 is short-circuited when the IGBT 1 is on, the current I C flowing through the IGBT 1 becomes a short-circuit current and this current reaches a saturation current value. After that, the collector-emitter voltage of the IGBT1 suddenly rises, the current does not flow in the diode 5, the Zener diode 12 and the transistor 15 turn on, and the gate charge of the IGBT1 passes through the resistor 4 and the emitter-base of the transistor 23. Is pulled out, and the gate-emitter voltage of the IGBT 1 is
The voltage drops due to the slope (soft cutoff) determined by the capacitor 18, and the IGBT 1 turns off. Here, the detection level of the collector-emitter voltage of the IGBT 1 is determined by the set values of the Zener diode 12 and the DC power supplies 6 and 7, and is generally set to a level at which normal ON / OFF does not cause malfunction. Therefore, the short-circuit current becomes large, and the IGBT 1 may be destroyed in the worst case due to the sudden jump-up voltage (ΔV CE ) due to −di / dt despite the soft interruption.
【０００７】[0007]
【発明が解決しようとする課題】短絡等の過電流発生時
に、短絡電流が飽和電流に達する以前に過電流保護回路
が動作し、遮断時の跳上り電圧を抑制することにある。When an overcurrent such as a short circuit occurs, the overcurrent protection circuit operates before the short circuit current reaches the saturation current to suppress the jump voltage at the time of interruption.
【０００８】また、過電流発生以外の異常等の場合にお
いてもソフト遮断が可能とすることにある。Further, it is to enable soft shutoff even in the case of an abnormality other than the occurrence of overcurrent.
【０００９】[0009]
【課題を解決するための手段】前述の目的を達成するた
めに、ＩＧＢＴのコレクタ・エミッタ間電圧を検出する
ダイオードの低圧側に直列に、外部信号によりオン，オ
フできる開閉手段を備えた。In order to achieve the above-mentioned object, a switching means which can be turned on / off by an external signal is provided in series with the low voltage side of the diode for detecting the collector-emitter voltage of the IGBT.
【００１０】ＩＧＢＴのコレクタ・エミッタ間電圧を検
出するダイオードの低圧側に直列に備えた開閉手段を用
いて、外部信号により短絡電流が飽和する以前にこの開
閉手段を開にすることにより、等価的に検出レベル以上
となるので過電流保護回路（ソフト遮断回路）が動作す
るので短絡電流および−ｄｉ／ｄｔが小さくなり、−ｄ
ｉ／ｄｔによる跳上り電圧（ΔＶCE）も小さくなるので
ＩＧＢＴを安全にターンオフすることができる。By using the switching means provided in series on the low voltage side of the diode for detecting the collector-emitter voltage of the IGBT, the switching means is opened before the short-circuit current is saturated by an external signal. Since the current exceeds the detection level, the overcurrent protection circuit (soft shutoff circuit) operates, and the short-circuit current and -di / dt are reduced, and -d
Since the jump voltage (ΔV CE ) due to i / dt is also small, the IGBT can be safely turned off.
【００１１】[0011]
【発明の実施の形態】以下、図面に基づきこの発明の実
施例を詳細に説明する。図１はこの発明による一実施例
を示す回路構成例、図２はその動作を示す波形図であ
る。図１に示すように、従来技術に対してＩＧＢＴのコ
レクタ・エミッタ間電圧を検出するダイオード５の低圧
側に直列に開閉手段として、直流電源２９，ホトカプラ
２６，ダイオード２８，抵抗２５，トランジスタ２７で
構成される回路を接続する。ここで、ダイオード２８は
逆電圧保護用に挿入しているものであり、なくてもかま
わない。また、メインのスイッチとしてのホトカプラ２
６は、取扱いを容易にするための絶縁を目的としてい
る。さらに、トランジスタ２７は、外部からの情報を入
力するためのものである。なお、ホトカプラ２６，トラ
ンジスタ２７としては高速動作が可能な素子を選択す
る。通常は、トランジスタ２７の外部情報としては、入
力(ＶEXT）が入っており、ホトカプラ２６の出力側はオ
ンしている。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a circuit configuration example showing an embodiment according to the present invention, and FIG. 2 is a waveform diagram showing its operation. As shown in FIG. 1, a DC power supply 29, a photocoupler 26, a diode 28, a resistor 25, and a transistor 27 are provided as switching means in series with the low voltage side of the diode 5 that detects the collector-emitter voltage of the IGBT as compared with the conventional technique. Connect the configured circuits. Here, the diode 28 is inserted for reverse voltage protection and may be omitted. Also, the photo coupler 2 as the main switch
6 is intended for insulation for easy handling. Further, the transistor 27 is for inputting information from the outside. Elements that can operate at high speed are selected as the photocoupler 26 and the transistor 27. Normally, the external information of the transistor 27 includes an input (V EXT ) and the output side of the photocoupler 26 is on.
【００１２】たとえば、トランジスタ２７の外部情報と
してＩC を観測し、通常の３倍になった時にトランジス
タ２７の入力(ＶEXT）がなくなるように設定された回路
が組み込まれているものとして、負荷２が短絡し、ＩＧ
ＢＴ１に短絡電流ＩC が流れる場合について説明しま
す。ＩＧＢＴ１の短絡電流ＩC が通常の３倍になった時
にトランジスタ２７の入力(ＶEXT）がなくなるため、ホ
トカプラ２６の出力側はオフし、ダイオード５には電流
が流れなくなりツェナーダイオード１２，トランジスタ
１５がオンし、抵抗４，トランジスタ２３のエミッタ・
ベース間を介してＩＧＢＴ１のゲート電荷が引き抜かれ
ＩＧＢＴ１のゲート・エミッタ間電圧は、抵抗１６，コ
ンデンサ１８で決まるスロープ(ソフト遮断)で低下しＩ
ＧＢＴ１はターンオフする。ここで、短絡電流ＩC は通
常の３倍レベルであるため（一般的に飽和電流は、定格
電流の５〜１０倍程度）−ｄｉ／ｄｔが小さくなり、−
ｄｉ／ｄｔによる跳上り電圧（ΔＶCE）も小さくなるの
でＩＧＢＴを安全にターンオフすることが可能となる。For example, if I C is observed as the external information of the transistor 27, and a circuit is set so that the input (V EXT ) of the transistor 27 disappears when it becomes three times the normal load, the load 2 short-circuited, IG
The case where the short-circuit current I C flows through BT1 is explained. Since the input (V EXT ) of the transistor 27 is lost when the short-circuit current I C of the IGBT 1 is three times the normal current, the output side of the photocoupler 26 is turned off, and no current flows through the diode 5 and the zener diode 12 and the transistor 15 Turns on, the resistor 4, the emitter of the transistor 23
The gate charge of the IGBT1 is extracted through the base, and the gate-emitter voltage of the IGBT1 decreases due to the slope (soft cutoff) determined by the resistor 16 and the capacitor 18.
GBT1 turns off. Here, since the short-circuit current I C is at a level three times the normal level (generally, the saturation current is about 5 to 10 times the rated current), -di / dt becomes small, and-
Since the jumping voltage (ΔV CE ) due to di / dt is also small, it is possible to safely turn off the IGBT.
【００１３】また、ＩＧＢＴのコレクタ・エミッタ間電
圧を検出するダイオード５の低圧側に直列に接続される
開閉手段としては、直流電源２９を絶縁すればダイオー
ド２８に並列にトランジスタ２７（他の半導体スイッチ
でも可）を接続し、その接続点と直列に抵抗２５，直流
電源２９を接続してもよい。As the switching means connected in series to the low voltage side of the diode 5 for detecting the collector-emitter voltage of the IGBT, if the DC power source 29 is insulated, the transistor 27 (other semiconductor switch) is connected in parallel to the diode 28. However, the resistor 25 and the DC power supply 29 may be connected in series with the connection point.
【００１４】以上は、トランジスタ２７の外部情報とし
て電流検出の場合であるが、外部情報としては監視する
対象を並列に（温度等）自由に設定し、どれか一つでも
異常な時にトランジスタ２７の入力(ＶEXT）がなくなる
ように設定された回路を組み込んでおけばよい。The above is the case of detecting the current as the external information of the transistor 27, but as the external information, the objects to be monitored can be freely set in parallel (such as temperature), and when any one of them is abnormal, the transistor 27 can be detected. A circuit set so that the input (V EXT ) is removed may be incorporated.
【００１５】[0015]
【発明の効果】本発明によれば、外部情報によってオ
ン，オフする開閉手段を動作させることにより過電流保
護回路（ソフト遮断回路）を動作させることができるた
め、自由な設定レベルでＩＧＢＴを安全にターンオフす
ることができる。According to the present invention, the overcurrent protection circuit (soft cutoff circuit) can be operated by operating the opening / closing means that is turned on / off according to external information, so that the IGBT can be safely set at a freely set level. Can be turned off.
【図１】本発明の一実施例を示す回路図。FIG. 1 is a circuit diagram showing one embodiment of the present invention.
【図２】本発明のその動作を示す波形図。FIG. 2 is a waveform diagram showing the operation of the present invention.
【図３】従来技術の回路図。FIG. 3 is a circuit diagram of a conventional technique.
【図４】従来技術の波形図。FIG. 4 is a waveform diagram of a conventional technique.
１…ＩＧＢＴ、２…負荷、３，６，７，２９…直流電
源、４，８，１０，１４，１６，１７，２０，２１，２
５…抵抗、５，１９，２８…ダイオード、９，２６…ホ
トカプラ、１１，１５，２２，２３，２４，２７…トラ
ンジスタ、１２…ツェナーダイオード、１３，１８…コ
ンデンサ。1 ... IGBT, 2 ... Load, 3, 6, 7, 29 ... DC power supply, 4, 8, 10, 14, 16, 17, 20, 21, 21,
5 ... Resistor, 5, 19, 28 ... Diode, 9, 26 ... Photocoupler, 11, 15, 22, 23, 24, 27 ... Transistor, 12 ... Zener diode, 13, 18 ... Capacitor.
Claims (1)
出する手段を有し、検出されたコレクタ・エミッタ間電
圧に基づいてＩＧＢＴをターンオフするＩＧＢＴの保護
回路において、コレクタ・エミッタ間電圧を検出する手
段に外部信号によりオン，オフできる開閉手段を接続す
ることを特徴とするＩＧＢＴの保護回路。1. A means for detecting a collector-emitter voltage in an IGBT protection circuit having means for detecting a collector-emitter voltage of an IGBT, and turning off the IGBT based on the detected collector-emitter voltage. An IGBT protection circuit characterized in that an opening / closing means that can be turned on / off by an external signal is connected to the.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25848995A JPH09102735A (en) | 1995-10-05 | 1995-10-05 | IGBT protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25848995A JPH09102735A (en) | 1995-10-05 | 1995-10-05 | IGBT protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09102735A true JPH09102735A (en) | 1997-04-15 |
Family
ID=17320924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25848995A Pending JPH09102735A (en) | 1995-10-05 | 1995-10-05 | IGBT protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09102735A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005045099A1 (en) * | 2005-09-21 | 2006-08-10 | eupec Europäische Gesellschaft für Leistungshalbleiter mbH | Desaturation circuitry for insulated gate bipolar transistor, has switching component switched between gate and collector of bipolar transistor, where gate voltage is lowered until voltage lies around forward bias of diode |
-
1995
- 1995-10-05 JP JP25848995A patent/JPH09102735A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005045099A1 (en) * | 2005-09-21 | 2006-08-10 | eupec Europäische Gesellschaft für Leistungshalbleiter mbH | Desaturation circuitry for insulated gate bipolar transistor, has switching component switched between gate and collector of bipolar transistor, where gate voltage is lowered until voltage lies around forward bias of diode |
| US7724065B2 (en) | 2005-09-21 | 2010-05-25 | Infineon Technologies Ag | Desaturation circuit for an IGBT |
| DE102005045099B4 (en) * | 2005-09-21 | 2011-05-05 | Infineon Technologies Ag | Desaturation circuit with an IGBT |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5485341A (en) | Power transistor overcurrent protection circuit | |
| JP5761215B2 (en) | Gate drive circuit | |
| JP6197685B2 (en) | Gate drive circuit | |
| US5200878A (en) | Drive circuit for current sense igbt | |
| US5432471A (en) | Insulated gate semiconductor device | |
| US4954917A (en) | Power transistor drive circuit with improved short circuit protection | |
| JP2777307B2 (en) | Short circuit protection circuit | |
| EP0730347A2 (en) | Semiconductor device | |
| JP2010130557A (en) | Gate driving device | |
| US5121283A (en) | Overcurrent protective circuit for electrostatic self-turn-off devices | |
| JP4479570B2 (en) | Switching circuit with protection function and protection circuit | |
| JPH09102735A (en) | IGBT protection circuit | |
| JP3649154B2 (en) | Overcurrent protection device | |
| JP3596415B2 (en) | Inductive load drive circuit | |
| JPH0473327B2 (en) | ||
| WO2022123977A1 (en) | Driving device for voltage-control type semiconductor element | |
| JP2022013339A (en) | Short circuit determination device, and switch device | |
| JP3477566B2 (en) | Gate drive circuit with overcurrent protection function | |
| JP3764259B2 (en) | Inverter device | |
| JP3008484B2 (en) | Protection circuit | |
| EP0614278A1 (en) | Drive circuit for use with voltage-driven semiconductor device | |
| JPH0685496B2 (en) | Gate drive circuit for electrostatic induction type self-extinguishing device | |
| JP3006195B2 (en) | Level conversion circuit | |
| JP3671796B2 (en) | Drive device for current control element | |
| JPH0521723A (en) | Power transistor |