Overvoltage protection circuit of semiconductor device and control method thereof

Abstract

The invention provides an overvoltage protection circuit of a semiconductor device and a control method of the overvoltage protection circuit, and the overvoltage protection circuit comprises a first turn-off module which is electrically connected with a gate pole and an anode of the semiconductor device and is used for preventing current from flowing from the gate pole to a cathode of the semiconductor device; the overvoltage energy taking control module is electrically connected with the gate pole, the anode and the first turn-off module. The overvoltage energy taking control module is used for controlling the first turn-off module to be turned off when the semiconductor device is in an overvoltage state. When it is detected that the semiconductor device is in an overvoltage state, the impedance of the overvoltage energy-taking control module is reduced, so that current passes through a branch where the overvoltage energy-taking control module is located and is conducted from an anode of the semiconductor device to a gate pole, the overvoltage energy-taking control module controls the first turn-off module to be turned off, and the current enters and is conducted from the gate pole to a cathode; and overvoltage protection of the semiconductor device is completed. A sampling module in the prior art is replaced by the overvoltage energy taking control module, so that the problem that the overvoltage protection circuit of the semiconductor device is complex in structure is solved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to an overvoltage protection circuit of a semiconductor device and a control method thereof. Background Art

[0002] In the prior art, the voltage sampling module of the overvoltage protection circuit of the semiconductor device detects the positive and negative voltages V AK When the threshold is reached, the shutdown circuit is controlled to fail, ensuring that the current introduced from the anode A by the overvoltage trigger module triggers the power semiconductor device to enter the on state through the gate G. The power supply and control signal of the shutdown circuit come from other components of the sampling module outside the overvoltage trigger module. The power supply and control signal of the shutdown circuit need to be obtained from components outside the overvoltage trigger module, which usually involves additional circuit components, such as power management circuits and control logic circuits, thereby increasing the complexity and cost of the entire protection circuit. Summary of the invention

[0003] The main purpose of the present application is to provide an overvoltage protection circuit for a semiconductor device and a control method thereof, so as to solve the problem of complex structure of the overvoltage protection circuit of the semiconductor device in the prior art.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, an overvoltage protection circuit of a semiconductor device is provided, including: a first shutdown module, electrically connected to the gate and anode of the semiconductor device, respectively, and the first shutdown module is used to prevent current from flowing from the gate to the cathode of the semiconductor device; an overvoltage energy control module, electrically connected to the gate, the anode and the first shutdown module, respectively, and the overvoltage energy control module is used to control the first shutdown module to be closed when the semiconductor device is in an overvoltage state.

[0005] Optionally, the overvoltage energy control module includes: a voltage-controlled variable impedance unit and an overvoltage backup control unit, wherein the voltage-controlled variable impedance unit is electrically connected to the anode and the overvoltage backup control unit, respectively, and is used to conduct the current of the anode to the gate when the semiconductor device is in an overvoltage state; the overvoltage backup control unit is electrically connected to the first shutdown module, and is used to provide a shutdown control signal to the first shutdown module.

[0006] Optionally, the overvoltage energy control module further includes: an overvoltage backup energy supply unit, one end of which is electrically connected to the gate and the overvoltage backup control unit respectively, for supplying energy to the first shutdown module.

[0007] Optionally, the overvoltage protection circuit further includes a second shutdown module, which is electrically connected to the cathode and the first shutdown module respectively, and is used to make the gate and the cathode in a conducting state.

[0008] Optionally, the voltage-controlled variable impedance unit includes any one or more of a Zener diode, a transient voltage suppression diode, a breakdown diode and a thyristor.

[0009] Optionally, the first shutdown module includes a shutdown device and / or a capacitor.

[0010] Optionally, the first shutdown module further includes a gate driver, wherein the gate driver is electrically connected to the shutdown device and is used to control the shutdown device to be turned on or off.

[0011] Optionally, the turn-off device includes one of the following: HEMT and MOSFET.

[0012] According to another aspect of the present application, a control method for an overvoltage protection circuit of a semiconductor device is provided, the control method being used to control the overvoltage protection circuit, the control method comprising: obtaining the voltage between the anode and the gate of the semiconductor device; when the voltage exceeds the threshold voltage of the semiconductor device, controlling the overvoltage energy acquisition control module of the overvoltage protection circuit to send a first control signal to a first shutdown module of the overvoltage protection circuit, so that the first shutdown module changes from an on state to a off state upon receiving the first control signal, thereby preventing current from flowing from the gate to the cathode of the semiconductor device.

[0013] Optionally, the control method also includes: obtaining the voltage between the anode and the gate of the semiconductor device; when the voltage exceeds the threshold voltage of the semiconductor device, controlling the overvoltage energy acquisition control module of the overvoltage protection circuit to send the first control signal to the first shutdown module, and sending a second control signal to the second shutdown module of the overvoltage protection circuit, so that the second shutdown module is in the open state when receiving the second control signal, and the first shutdown module is in the closed state when receiving the first control signal, so as to prevent current from flowing from the gate to the cathode.

[0014] By applying the technical solution of the present application, a first shutdown module and an overvoltage energy acquisition control module are provided in the overvoltage protection circuit, the first shutdown module is electrically connected to the gate and anode of the semiconductor device respectively, and the first shutdown module is used to prevent the current from flowing from the gate to the cathode of the semiconductor device; the overvoltage energy acquisition control module is electrically connected to the gate, the anode and the first shutdown module respectively, and the overvoltage energy acquisition control module is used to control the first shutdown module to be turned off when the semiconductor device is in an overvoltage state. When the overvoltage energy acquisition control module detects that the semiconductor device is in an overvoltage state, the voltage applied to the overvoltage energy acquisition control module at this time is higher than the voltage threshold of the overvoltage energy acquisition control module, and the impedance of the overvoltage energy acquisition control module will be reduced, so that the current passes through the branch where the overvoltage energy acquisition control module is located from the anode of the semiconductor device to the gate, and the overvoltage energy acquisition control module controls the first shutdown module to be turned off, so that the current enters and conducts from the gate of the semiconductor device to the cathode, triggering the semiconductor device to enter the on state, and at this time the anode-cathode voltage is clamped to near zero, thereby avoiding the overvoltage failure of the semiconductor device and completing the overvoltage protection of the semiconductor device. The present application solves the problem of complex overvoltage protection circuit structure of semiconductor devices in the prior art by adopting the above-mentioned overvoltage energy control module to replace the sampling module in the prior art to detect the voltage of the semiconductor device and control the first shutdown module to shut down to protect the semiconductor device from overvoltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 A circuit structure schematic diagram of an embodiment of an overvoltage protection circuit of a first semiconductor device according to the present application is shown;

[0017] Figure 2 A circuit structure schematic diagram of an embodiment of an overvoltage protection circuit of a second semiconductor device of the present application is shown;

[0018] Figure 3 A schematic diagram showing a structural connection method in an overvoltage energy acquisition control module in a first overvoltage protection circuit of the present application is shown;

[0019] Figure 4 A schematic diagram showing a structural connection method in an overvoltage energy acquisition control module in a second overvoltage protection circuit of the present application is shown;

[0020] Figure 5 A schematic diagram showing a structural connection mode in an overvoltage energy taking control module in a third overvoltage protection circuit of the present application is shown;

[0021] Figure 6Shows a schematic diagram of the structure of various overvoltage backup control units of the present application;

[0022] Figure 7 The schematic diagrams of the structures of various voltage-controlled variable impedance units of the present application are shown;

[0023] Figure 8 A schematic diagram showing a topological structure of an overvoltage protection circuit of a first semiconductor device of the present application is shown;

[0024] Fig. 9 A schematic diagram showing a topological structure of an overvoltage protection circuit of a second semiconductor device of the present application is shown;

[0025] Fig.10 A schematic diagram showing a topological structure of an overvoltage protection circuit of a third semiconductor device of the present application is shown;

[0026] Fig.11 A schematic diagram showing a topological structure of an overvoltage protection circuit of a fourth semiconductor device of the present application is shown;

[0027] Fig.12 A schematic diagram showing a topological structure of an overvoltage protection circuit of a fifth semiconductor device of the present application is shown;

[0028] Fig.13 A schematic diagram showing a topological structure of an overvoltage protection circuit of a sixth semiconductor device of the present application is shown;

[0029] Fig.14 A schematic diagram of the flow structure of a control method for an overvoltage protection circuit of a semiconductor device of the present application is shown.

[0030] The above drawings include the following reference numerals:

[0031] 10. First shutdown module; 11. Shutdown device; 12. Capacitor; 13. Gate driver; 20. Semiconductor device; 30. Overvoltage energy control module; 31. Voltage-controlled variable impedance unit; 32. Overvoltage standby control unit; 33. Overvoltage standby energy supply unit; 321. First overvoltage standby control subunit; 322. Second overvoltage standby control subunit; 331. First diode device; 332. Second diode device; 40. Second shutdown module; 50. Energy storage structure; 60. Negative temperature coefficient thermistor; 70. Refrigeration plate. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when it is described that an element is "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0036] As described in the background technology, the voltage sampling module of the overvoltage protection circuit of the semiconductor device in the prior art detects the positive and negative voltages V AK When the threshold is reached, the shutdown circuit is controlled to fail, ensuring that the current introduced from the anode A by the overvoltage trigger module triggers the power semiconductor device to enter the on state through the gate G. The power supply and control signal of the shutdown circuit are both from other components of the sampling module outside the overvoltage trigger module. The power supply and control signal of the shutdown circuit need to be obtained from components outside the overvoltage trigger module, which usually involves additional circuit components, such as power management circuits and control logic circuits, thereby increasing the complexity and cost of the entire protection circuit. In order to solve the problem of the complex structure of the overvoltage protection circuit of the semiconductor device, the embodiment of the present application provides an overvoltage protection circuit of a semiconductor device and a control method thereof.

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0038] According to one aspect of the present application, an overvoltage protection circuit for a semiconductor device is provided. Figure 1As shown, it includes: a first shutdown module 10, which is electrically connected to the gate G and anode A of the semiconductor device 20 respectively, and the first shutdown module 10 is used to prevent current from flowing from the gate G to the cathode K of the semiconductor device 20; an overvoltage energy control module 30, which is electrically connected to the gate G, the anode A and the first shutdown module 10 respectively, and the overvoltage energy control module 30 is used to control the first shutdown module 10 to be turned off when the semiconductor device 20 is in an overvoltage state.

[0039] When the overvoltage energy acquisition control module detects that the semiconductor device is in an overvoltage state, the voltage applied to the overvoltage energy acquisition control module is higher than the voltage threshold of the overvoltage energy acquisition control module, and the impedance of the overvoltage energy acquisition control module is reduced, so that the current passes through the branch where the overvoltage energy acquisition control module is located from the anode of the semiconductor device to the gate. The overvoltage energy acquisition control module controls the first shutdown module to close, so that the current flows from the gate of the semiconductor device to the cathode, triggering the semiconductor device to enter the on state. At this time, the anode-cathode voltage is clamped to close to zero, thereby avoiding overvoltage failure of the semiconductor device and completing overvoltage protection of the semiconductor device. The present application solves the problem of complex overvoltage protection circuit structure of semiconductor devices in the prior art by using the above-mentioned overvoltage energy acquisition control module instead of the sampling module in the prior art to detect the voltage of the semiconductor device and controlling the first shutdown module to close to protect the semiconductor device from overvoltage.

[0040] The voltage applied to both ends of the overvoltage energy control module is the same voltage as the voltage applied between the anode and cathode of the semiconductor device. Therefore, when it is detected that the semiconductor device is under overvoltage, it indicates that the voltage across the overvoltage energy control module also exceeds the threshold voltage of the overvoltage energy control module.

[0041] In the prior art, the circuit structure of the sampling module is relatively complex. The present application adopts an overvoltage energy acquisition control module to replace the sampling module in the prior art, which can not only simplify the structure of the overvoltage protection circuit, but also avoid the introduction of the voltage sampling module and other external components, increase the potential failure points of the circuit, and reduce the reliability of the overvoltage protection circuit. In particular, under extreme working conditions, such as high temperature, high vibration or electromagnetic interference environment, these additional components may cause signal distortion or unstable power supply, thereby affecting the performance of the overvoltage protection circuit.

[0042] In some optional embodiments, such as Figure 2 As shown, the overvoltage protection circuit further includes a second shutdown module 40, which is electrically connected to the cathode K and the first shutdown module 10 respectively, and is used to make the gate G and the cathode K in a conducting state.

[0043] In the above optional implementation, if Figure 2As shown, a second shutdown module 40 can also be connected to the cathode K of the semiconductor device 20. When the overvoltage energy acquisition control module 30 detects that the semiconductor device 20 is in an overvoltage state, it controls the second shutdown module 40 to be turned on and controls the first shutdown module 10 to be turned off. Through the joint action of the first shutdown module 10 and the second shutdown module 40, the current at the anode A is prevented from flowing directly from the branch where the overvoltage energy acquisition control module 30 is located through the branch where the first shutdown module 10 is located, so that the current enters from the gate of the semiconductor device and flows out from the cathode, thereby achieving effective overvoltage protection. And when the shutdown device in the first shutdown module 10 is a P-type metal oxide semiconductor field effect transistor (Metal-Oxide-SemiconductorField-Effect Transistor, MOSFET) or a depletion type high electron mobility transistor (High ElectronMobility Transistor, HEMT), the overvoltage energy acquisition control module 30 will also supply energy to the first shutdown module 10.

[0044] The first shutoff module 10 matched with the second shutoff module 40 only has a shutoff device. Figure 1 The scheme in FIG. 1 is only a first shutdown module 10, and the internal circuit of the first shutdown module 10 has a shutdown device and a capacitor. In the case where the shutdown device in the first shutdown module 10 is a P-type MOSFET or a depletion-type HEMT, the overvoltage energy acquisition control module 30 will also supply energy to the first shutdown module 10.

[0045] In some optional embodiments, such as Figures 3 to 5 As shown, the overvoltage energy control module 30 includes: a voltage-controlled variable impedance unit 31 and an overvoltage standby control unit 32, wherein the voltage-controlled variable impedance unit 31 is electrically connected to the anode A and the overvoltage standby control unit 32, respectively, for conducting the current of the anode A to the gate G when the semiconductor device is in an overvoltage state; the overvoltage standby control unit 32 is electrically connected to the first shutdown module, for providing a shutdown control signal to the first shutdown module.

[0046] In the above optional implementation, the voltage-controlled variable impedance unit and the overvoltage standby control unit are connected in series between the anode of the semiconductor device and the reference ground of the power supply of the first shutdown module. When the voltage between the anode and cathode of the semiconductor device is greater than the preset threshold of the semiconductor device, the voltage across the voltage-controlled variable impedance unit reaches the threshold, and the impedance is reduced to introduce the anode current into the gate. After the anode current is introduced into the gate, the overvoltage standby control unit sends a control signal to the first shutdown module to turn off the first shutdown module to avoid the current flowing to the cathode through the first shutdown module with lower impedance, and the semiconductor device cannot be triggered to enter the on state through the gate, making the overvoltage protection of the semiconductor device invalid. The first shutdown module is turned off to allow the current to flow from the gate of the semiconductor device to the cathode, so that the device is turned on to achieve effective overvoltage protection.

[0047] In some optional embodiments, such as Figures 3 to 5 As shown, the overvoltage energy control module 30 also includes: an overvoltage standby energy supply unit 33, one end of which is electrically connected to the gate G and the overvoltage standby control unit 32, respectively, for supplying energy to the first shutdown module. The voltage-controlled variable impedance unit 31, the overvoltage standby control unit 32, and the overvoltage standby energy supply unit 33 can be connected in a variety of ways. Those skilled in the art can electrically connect the above three units according to actual conditions, so that the circuit connection method is more flexible.

[0048] In the above optional implementation, if Figures 3 to 5 As shown, the voltage-controlled variable impedance unit 31, the overvoltage standby control unit 32 and the overvoltage standby energy supply unit 33 are connected in series between the anode A of the semiconductor device 20 and the reference ground of the power supply of the first shutdown module 10. The gate G of the semiconductor device 20 can be as follows Figure 3 As shown, the gate G is connected between the voltage-controlled variable impedance unit 31 and the overvoltage standby control unit 32. Figure 4 It is shown to be connected between the overvoltage backup control unit 32 and the overvoltage backup energy supply unit 33 . Figure 3 The medium overvoltage standby control unit 32 can exchange positions with the overvoltage standby energy supply unit 33. Figure 4 The medium voltage controlled variable impedance unit 31 can be exchanged with the overvoltage standby control unit 32. The gate G can also be Figure 5As shown, the voltage-controlled variable impedance unit 31, the overvoltage standby control unit 32 and the overvoltage standby energy supply unit 33 are connected to a certain interface of the overvoltage standby energy supply unit 33, and the positions of the voltage-controlled variable impedance unit 31, the overvoltage standby control unit 32 and the overvoltage standby energy supply unit 33 can be exchanged with each other. The overvoltage standby control unit 32 and the overvoltage standby energy supply unit 33 do not need to exist at the same time. When the shutdown device in the first shutdown module is an N-type MOSFET or an enhanced HEMT, the overvoltage standby energy supply unit 33 may not be set, or the overvoltage standby energy supply unit 33 may be short-circuited or open-circuited. The overvoltage protection circuit in the present application has various connection methods, and a variety of shutdown devices can be used, and the application range is wide.

[0049] In some optional implementations, the voltage-controlled variable impedance unit includes any one or more of a Zener diode, a transient voltage suppressor diode, a breakdown diode, and a thyristor. Figure 6 As shown, the voltage-controlled variable impedance unit 31 can be Figure 6 (a) shows a metal oxide variable resistor (MOV). Figure 6 As shown in (b), the voltage-controlled variable impedance unit 31 may be a Zener diode or a transient voltage suppressor (TVS) diode; the voltage-controlled variable impedance unit 31 may be a reverse blocking Zener diode or a TVS diode (not shown in the figure); Figure 6 As shown in (c), the voltage-controlled variable impedance unit 31 may be a Zener diode connected in series with a reverse diode or a TVS diode connected in series with a reverse diode; Figure 6 As shown in (d), the voltage-controlled variable impedance unit 31 may be a breakdown diode (Breakover Diodes, BOD); the voltage-controlled variable impedance unit 31 may be a BOD with reverse blocking characteristics (not shown in the figure); Figure 6 As shown in (e), the voltage-controlled variable impedance unit 31 may be a BOD connected in series with a reverse diode; Figure 6 As shown in (f), the voltage-controlled variable impedance unit 31 may be a crowbar circuit composed of a Zener diode and a thyristor or a crowbar circuit composed of a TVS and a thyristor; Figure 6 As shown in (g), the voltage-controlled variable impedance unit 31 can be any one of a crowbar circuit composed of a reverse-blocking Zener diode and a thyristor, a crowbar circuit composed of a Zener diode and a thyristor connected in reverse series with a diode, and a crowbar circuit composed of a TVS diode and a thyristor; Figure 6 As shown in (h), the voltage-controlled variable impedance unit 31 may be a crowbar circuit composed of a BOD and a thyristor; the voltage-controlled variable impedance unit 31 may be a BOD with reverse blocking characteristics (not shown in the figure); Figure 6As shown in (i), the voltage-controlled variable impedance unit 31 can be a crowbar circuit composed of a BOD of a reverse series diode and a thyristor. The voltage-controlled variable impedance unit 31 with reverse blocking characteristics and a reverse series diode is generally used for reverse resistance power semiconductor devices, and the voltage-controlled variable impedance unit 31 without reverse blocking and reverse series diode is generally used for asymmetric or reverse conduction power semiconductor devices. Using the above device as the internal device of the voltage-controlled variable impedance unit 31 can more sensitively detect that the voltage acting on both ends of the voltage-controlled variable impedance unit 31 is greater than the threshold voltage of the voltage-controlled variable impedance unit 31. When the voltage across the voltage-controlled variable impedance unit 31 is greater than the threshold voltage of the voltage-controlled variable impedance unit 31, the resistance of the voltage-controlled variable impedance unit 31 itself will decrease, thereby conducting the current of the anode A to the gate, and the current will flow from the gate into the semiconductor device and out from the cathode, thereby better completing the overvoltage protection of the semiconductor device.

[0050] like Figure 7 As shown, the overvoltage standby control unit 32 may be a transformer, such as Figure 7 (a), an optical coupler or optical fiber, such as Figure 7 (b) As shown in the figure, the overvoltage standby control unit 32 adopts the above-mentioned device, which can better provide a control voltage signal for the first shutdown module to control the first shutdown module to shut down.

[0051] Initially, the semiconductor device is in the on state, and current is injected into the semiconductor device from the anode of the semiconductor device and flows out from the cathode. There are two ways to turn off the semiconductor device. The first is as follows: Figures 8 to 10 As shown, the overvoltage protection circuit only has the first shutdown module 10, and the second is as follows Fig.11 As shown, the overvoltage protection circuit has a first shutdown module 10 and a second shutdown module 40.

[0052] In some optional embodiments, such as Figures 8 to 11 As shown, the first shutdown module 10 includes a shutdown device 11 and / or a capacitor 12. When the first shutdown module 10 is used in conjunction with the second shutdown module 40, the first shutdown module 10 may only have a shutdown device. When there is only the first shutdown module 10 in the circuit, the internal circuit of the first shutdown module 10 has a shutdown device and a capacitor. The capacitor has a positive and negative pole. In the process from the semiconductor device being turned on to being turned off, the capacitor can provide an impedance lower than the branch where the cathode of the semiconductor device is located for the branch where the first shutdown module 10 is located, so that the current entering the semiconductor device from the anode flows out from the gate and flows through the branch where the first shutdown module 10 is located. The above two methods can be flexibly applied to enable the device to be turned off smoothly.

[0053] In some optional embodiments, the above-mentioned turn-off device includes one of the following: HEMT and MOSFET. Among them, MOSFET includes N-type MOSFET and P-type MOSFET, and HEMT includes depletion type and enhancement type. Depletion type HEMT and P-type MOSFET are turned on under negative voltage state, and enhancement type HEMT and N-type MOSFET are turned on under positive voltage state. Different types of turn-off devices can be used in the overvoltage protection circuit in this application, and the application range is wide.

[0054] In some embodiments, Figures 8 to 10 As shown, the first shutdown module 10 includes a shutdown device 11 and a capacitor 12. When the semiconductor device 20 is turned off, the shutdown device 11 is turned on, the negative electrode of the capacitor 12 is connected to the gate G, and the positive electrode of the capacitor 12 is connected to the cathode K, so that the voltage drop of the branch where the first shutdown module 10 is located is negative, which is lower than the voltage drop of the branch where the cathode K is located, so that the impedance of the branch where the first shutdown module 10 is located is lower, and the current of the semiconductor device 20 can be diverted from the anode A to the gate G, completing the commutation of the semiconductor device 20, so that the semiconductor device 20 is turned off. The first shutdown module 10 and the semiconductor device 20 form an integrated gate-commutated thyristor (IGCT).

[0055] In some embodiments, Figure 8 As shown, the first shutdown module 10 includes a shutdown device 11 and a capacitor 12, and the shutdown device is an N-type MOSFET or an enhanced HEMT. The overvoltage energy acquisition control module 30 only contains a voltage-controlled variable impedance unit 31 and an overvoltage standby control unit 32. The working principle is as follows: when the semiconductor device 20 is in the off state or the blocking state, when the anode-cathode voltage V AK When the threshold of the voltage-controlled variable impedance unit 31 is exceeded, the impedance of the voltage-controlled variable impedance unit 31 is reduced, and current is injected from the anode A to the gate G of the semiconductor device 20 through the primary side of the overvoltage standby control unit 32 optocoupler. The secondary side of the overvoltage standby control unit 32 optocoupler is turned on, and the gate of the shutdown device 11 of the first shutdown module 10 is grounded to ensure that the shutdown device 11 is turned off, thereby making the first shutdown module 10 controlled to fail, so that the current can flow smoothly from the anode A to the gate G and be injected into the semiconductor device. The semiconductor device 20 can be triggered to turn on, thereby achieving effective overvoltage protection for the semiconductor device 20.

[0056] In some embodiments, Fig. 9 As shown, the first shutdown module 10 includes a shutdown device 11 and a capacitor 12, and the shutdown device is a P-type MOSFET or a depletion-type HEMT ( Fig. 9The device shown in the figure is a depletion type HEMT). The overvoltage energy acquisition control module 30 includes a voltage-controlled variable impedance unit 31, an overvoltage standby control unit 32 and an overvoltage standby energy supply unit 33. The working principle is: when the semiconductor device 20 is in the off state or the blocking state, when the anode-cathode voltage V AK When the threshold of the voltage-controlled variable impedance unit 31 is exceeded, the impedance of the voltage-controlled variable impedance unit 31 is reduced, and current is injected from the anode A to the gate G of the semiconductor device 20 through the primary side of the overvoltage standby control unit 32 optocoupler, and the secondary side of the overvoltage standby control unit 32 optocoupler is turned on, connecting the gate of the shutdown device 11 to the reference ground, and the overvoltage standby energy supply unit 33 applies a voltage to the source of the shutdown device 11, clamping the voltage between the gate (reference ground) and the source of the shutdown device 11 to a voltage less than the shutdown drive voltage of the shutdown device 11, thereby ensuring the shutdown of the shutdown device 11, and then making the first shutdown module 10 controlled to fail, so that the current can smoothly flow from the anode A to the gate G and be injected into the semiconductor device, and the semiconductor device 20 can be triggered to turn on, thereby achieving effective overvoltage protection for the semiconductor device 20.

[0057] In some embodiments, Fig.10 As shown, the first shutdown module 10 includes a shutdown device 11, a capacitor 12 and a gate driver 13. The gate driver 13 is electrically connected to the shutdown device 11 and is used to control the shutdown device 11 to be turned on or off. The capacitor 12 is used to make the first shutdown module 10 have a lower voltage drop. The shutdown device 11 is a depletion-type HEMT. The overvoltage energy control module 30 contains a voltage-controlled variable impedance unit 31, an overvoltage standby control unit 32 and an overvoltage standby energy supply unit 33. The working principle is as follows: when the semiconductor device 20 is in the off state or the blocking state, when the anode-cathode voltage V AK When the threshold of the voltage-controlled variable impedance unit 31 is exceeded, the impedance of the voltage-controlled variable impedance unit 31 is reduced, and current is injected from the anode A to the gate G of the semiconductor device 20 through the primary side of the optical coupler of the overvoltage standby control unit 32. The secondary side of the optical coupler of the overvoltage standby control unit 32 is turned on, and the control input of the gate driver 13 is connected to the first reference ground (the first reference ground is the ground connected to the overvoltage standby control unit 32). The overvoltage standby energy supply unit 33 includes a first diode device 331 and a second diode device 332. The diode device can be a Zener diode or a TVS diode. The first diode device 331 clamps the first reference ground to the low voltage rail of the gate driver 13, and the second diode device 332 clamps the second reference ground ( Fig.10The triangle connected to the middle gate driver 13 is the second reference ground) and is clamped to the high voltage rail of the gate driver 13, so that the gate driver 13 outputs a shutdown voltage signal to the shutdown device 11, ensuring that the shutdown device 11 is reliably shut down under the high driving capability of the gate driver 13, so that the first shutdown module 10 is controlled to fail, thereby realizing effective overvoltage protection for the semiconductor device 20.

[0058] In some embodiments, Fig.11 As shown, the first shutdown module 10 only includes a shutdown device 11. When the semiconductor device 20 is turned off, the overvoltage energy acquisition control module 30 controls the second shutdown module 40 to turn off, and the first shutdown module 10 is turned on to commutate the current to the gate G, thereby turning off the semiconductor device 20. The first shutdown module 10, the second shutdown module 40 and the semiconductor device 20 form an emitter turn-off thyristor (ETO).

[0059] In some embodiments, Fig.11 As shown, the shutdown device of the first shutdown module 10 is a depletion-type HEMT. The overvoltage energy acquisition control module 30 includes a voltage-controlled variable impedance unit 31, an overvoltage standby control unit 32 and an overvoltage standby energy supply unit 33. The overvoltage standby control unit 32 includes a first overvoltage standby control subunit 321 and a second overvoltage standby control subunit 322. The working principle is as follows: when the semiconductor device 20 is in the off state, when the anode-cathode voltage V of the semiconductor device 20 is detected AK When the threshold of the voltage-controlled variable impedance unit 31 is exceeded, the impedance of the voltage-controlled variable impedance unit 31 is reduced, and current is injected from the anode A to the gate G of the semiconductor device 20 through the primary side of the first overvoltage standby control subunit 321 optical coupler, the primary side of the second overvoltage standby control subunit 322 optical coupler, and the overvoltage standby energy supply unit 33. The overvoltage standby energy supply unit 33 is electrically connected to the first reference ground that generates a voltage exceeding the gate threshold voltage of the second shutdown module 40 relative to the cathode K, and the secondary side of the first overvoltage standby control subunit 321 optical coupler is turned on, and the first The gate of the shutdown device 11 (N-channel MOSFET) in the shutdown module 10 is connected to the cathode K, and the first shutdown module 10 is controlled to fail (turn off); the secondary side of the optocoupler of the second overvoltage standby control subunit 322 is turned on, and the gate of the shutdown device (N-channel MOSFET) in the second shutdown module 40 is connected to the first reference ground, and the second shutdown module 40 is controlled to be effective (open), and the current injected into the gate G flows out from the cathode K through the second shutdown module 40, triggering the semiconductor device 20 to turn on, thereby achieving reliable overvoltage protection.

[0060] The overvoltage protection circuit introduced above is a passive circuit. Fig.12As shown, an energy storage structure 50 is connected in parallel to the overvoltage backup energy supply unit 33 in the overvoltage protection circuit, so that the overvoltage protection circuit is converted into an active circuit. When the semiconductor device 20 is in an overvoltage state, the impedance of the voltage-controlled variable impedance unit 31 is reduced, and the branch where the voltage-controlled variable impedance unit 31 is located is turned on, and the current is conducted from the anode A to the gate G. Part of the current is used to power the first shutdown module 10 and other devices in the circuit, and the other part of the current enters the energy storage structure 50 and is stored in the energy storage structure 50. The stored part of the current is used to maintain the voltage-controlled variable impedance unit 31 in a low resistance state so that it remains on for a period of time, and the first shutdown module 10 is in a closed state. In this way, the semiconductor device 20 can be continuously in a conductive state, which can improve the reliable conduction degree of the semiconductor device 20.

[0061] Since the voltage-controlled variable impedance unit will be subjected to overvoltage, the operating temperature of the voltage-controlled variable impedance unit will be relatively high. If the temperature of the voltage-controlled variable impedance unit rises too high, the threshold of the overvoltage trigger of the voltage-controlled variable impedance unit will have a large deviation from the standard threshold, resulting in the semiconductor device not being protected from overvoltage in time, and thus damaged. Fig.13 As shown, an energy storage structure 50, a negative temperature coefficient thermistor 60 and a cooling plate 70 are provided in the overvoltage protection circuit, wherein the negative temperature coefficient thermistor 60 is connected in series between the cooling plate 70 and the energy storage structure 50, and the negative temperature coefficient thermistor 60 and the cooling plate 70 are relatively close to the voltage-controlled variable impedance unit 31 in the circuit, and the temperature change of the voltage-controlled variable impedance unit 31 can be detected. When the semiconductor device 20 is in an overvoltage state, the impedance of the voltage-controlled variable impedance unit 31 is reduced, and the current is conducted from the anode A to the gate G. A part of the current is used to power the first shutdown module 10 and other devices in the circuit, and the other part of the current enters the energy storage structure 50 and is stored by the energy storage structure 50. When the temperature of the voltage-controlled variable impedance unit 31 increases, the resistance of the negative temperature coefficient thermistor 60 will decrease, so that the discharge amount of the energy storage structure 50 to the cooling plate 70 will increase, and the cooling effect of the cooling plate 70 will be enhanced, thereby cooling the voltage-controlled variable impedance unit 31, so that the temperature of the voltage-controlled variable impedance unit 31 is maintained in a stable state, thereby keeping the overvoltage trigger threshold stable, and the overvoltage protection circuit can operate normally. Fig.12 and Fig.13 Structural references not mentioned in Fig. 9 and Fig.10 Description in .

[0062] Fig.14 FIG. 1 is a flow chart of a method for controlling an overvoltage protection circuit of a semiconductor device according to an embodiment of the present application. Fig.14 As shown, the method comprises the following steps:

[0063] Step S201, obtaining the voltage between the anode and the gate of the semiconductor device.

[0064] Specifically, when the semiconductor device is in the off state, the voltage between the anode and the gate (equivalent to the anode and the cathode) is detected to prevent the semiconductor device from being over-voltage and causing breakdown.

[0065] Step S202, when the voltage exceeds the threshold voltage of the semiconductor device, the overvoltage energy control module of the overvoltage protection circuit sends a first control signal to the first shutdown module of the overvoltage protection circuit, so that the first shutdown module changes from an open state to a closed state when receiving the first control signal, thereby preventing current from flowing from the gate to the cathode of the semiconductor device.

[0066] Specifically, once it is detected that the voltage between the anode and the gate of the semiconductor device exceeds the threshold voltage of the semiconductor device, the semiconductor device needs to be protected from overvoltage. Since the voltage between the anode and the gate of the semiconductor device is the same voltage as the voltage applied to the two ends of the overvoltage energy extraction control module, the voltage at the two ends of the overvoltage energy extraction control module also exceeds the threshold voltage, the impedance of the voltage-controlled variable impedance unit will decrease, and the current will flow through the branch where the overvoltage energy extraction control module is located. When the shutdown device in the first shutdown module is a positive voltage shutdown device, the overvoltage standby control unit in the overvoltage energy extraction control module is controlled to send a first control signal to the first shutdown module, close the first shutdown module, and make the current entering the branch where the overvoltage energy extraction control module is located enter the semiconductor device from the gate and flow out of the semiconductor device from the cathode, so that the semiconductor device is triggered, thereby completing effective overvoltage protection.

[0067] Specifically, when the shutdown device in the first shutdown module is a negative pressure shutdown device, the overvoltage standby control unit in the overvoltage energy acquisition control module is controlled to send a first control signal to the first shutdown module, and the overvoltage standby energy supply unit in the overvoltage energy acquisition control module is controlled to supply energy to the first shutdown module, so as to close the first shutdown module, and allow the current entering the branch where the overvoltage energy acquisition control module is located to enter the semiconductor device from the gate, so that the semiconductor device is triggered, thereby completing effective overvoltage protection.

[0068] Through this embodiment, an overvoltage energy acquisition control module can be used to replace the sampling module in the prior art to detect the voltage applied to the semiconductor device. When the semiconductor device is detected to be in an overvoltage state, the voltage at both ends of the overvoltage energy acquisition control module also exceeds its own voltage threshold. At this time, the impedance of the overvoltage energy acquisition control module will be reduced, so that the current passes through the branch where the overvoltage energy acquisition control module is located from the anode of the semiconductor device to the gate, and the first shutdown module is controlled to be closed, so that the current flows from the gate into the semiconductor device, triggering the semiconductor device to enter the conduction state from the shutdown state. At this time, the anode-cathode voltage is clamped to near zero, thereby avoiding overvoltage failure of the semiconductor device, completing the overvoltage protection of the semiconductor device in the shutdown state, and improving the reliability of the overvoltage protection circuit. The overvoltage protection current in this application can be applied to a variety of shutdown devices, and has stronger versatility. The use of the overvoltage energy acquisition control module instead of the sampling module in the prior art solves the problem of complex structure of the overvoltage protection circuit of the semiconductor device in the prior art.

[0069] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the control method of the overvoltage protection circuit of the semiconductor device of the present application will be described in detail below in combination with specific embodiments.

[0070] In some optional embodiments, the control method also includes: obtaining the voltage between the anode and the gate of the semiconductor device; when the voltage exceeds the threshold voltage of the semiconductor device, controlling the overvoltage energy acquisition control module of the overvoltage protection circuit to send a first control signal to the first shutdown module, and sending a second control signal to the second shutdown module of the overvoltage protection circuit, so that the second shutdown module is in an open state when receiving the second control signal, and the first shutdown module is in a closed state when receiving the first control signal, thereby preventing current from flowing from the gate to the cathode.

[0071] In the above optional implementation, the method of making the current flow from the anode through the branch where the voltage-extraction control module is located and through the gate into the semiconductor device can also be a method of using the first shutdown module and the second shutdown module to work together. The shutdown devices in the first shutdown module and the second shutdown module can also be of various types, such as positive voltage shutdown devices and negative voltage shutdown devices. The combination of multiple branches and the selection of multiple devices make the overvoltage protection circuit diverse.

[0072] When the shutdown device in the first shutdown module is a positive voltage shutdown device, the impedance of the voltage-controlled variable impedance unit in the overvoltage energy acquisition control module will be reduced, and the current will flow through the branch where the overvoltage energy acquisition control module is located, and the overvoltage standby control unit in the overvoltage energy acquisition control module is controlled to send a first control signal to the first shutdown module to close the first shutdown module, and the overvoltage standby control unit in the overvoltage energy acquisition control module is controlled to send a second control signal to the second shutdown module to open the second shutdown module, so that the current entering the branch where the overvoltage energy acquisition control module is located enters the semiconductor device from the gate, so that the semiconductor device is triggered, thereby completing effective overvoltage protection. The principle of controlling the opening of the second shutdown module can refer to Fig.11 Description.

[0073] When the shutdown device in the first shutdown module is a negative pressure shutdown device, the overvoltage standby control unit in the overvoltage energy acquisition control module is controlled to send a first control signal to the first shutdown module, and the overvoltage standby energy supply unit in the overvoltage energy acquisition control module is controlled to provide energy to the first shutdown module, so as to close the first shutdown module, and the overvoltage standby control unit in the overvoltage energy acquisition control module is controlled to send a second control signal to the second shutdown module, so as to open the second shutdown module, so that the current entering the branch where the overvoltage energy acquisition control module is located enters the semiconductor device from the gate, so that the semiconductor device is triggered, thereby completing effective overvoltage protection. For the process of shutting down the first shutdown module, please refer to Fig. 9 Description in .

[0074] From the above description, it can be seen that the overvoltage protection circuit of the semiconductor device provided by the present application achieves the following technical effects:

[0075] 1) When the semiconductor device is detected to be in an overvoltage state, the overvoltage energy acquisition control module will reduce its own impedance, so that the current passes through the branch where the overvoltage energy acquisition control module is located from the anode of the semiconductor device to the gate, and controls the first shutdown module to close to achieve overvoltage protection, so that the current enters and conducts from the gate of the semiconductor device to the cathode, triggering the semiconductor device to enter the on state. At this time, the anode-cathode voltage is clamped to near zero, thereby avoiding overvoltage failure of the semiconductor device and completing overvoltage protection of the semiconductor device. The overvoltage energy acquisition control module is used to replace the sampling module in the prior art to detect the anode-cathode voltage of the semiconductor device, simplifying the composition of the overvoltage protection circuit.

[0076] 2) The present application adopts an overvoltage energy control module to replace the sampling module in the prior art, and can also avoid the introduction of a voltage sampling module and other external components, increase potential failure points of the circuit, and reduce the reliability of the overvoltage protection circuit.

[0077] 3) The voltage-controlled variable impedance unit, the overvoltage standby control unit and the overvoltage standby energy supply unit can have a variety of connection methods, and can use a variety of shutdown devices, so that the circuit connection method is more flexible and has a wide range of applications.

[0078] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An overvoltage protection circuit for a semiconductor device, characterized in that: include: A first shutoff module, electrically connected to the gate and anode of the semiconductor device respectively, and used to prevent current from flowing from the gate to the cathode of the semiconductor device; An overvoltage energy acquisition control module is electrically connected to the gate, the anode and the first shutdown module respectively, and is used to control the first shutdown module to be turned off when the semiconductor device is in an overvoltage state.

2. The overvoltage protection circuit according to claim 1, characterized in that: The overvoltage energy control module includes: a voltage-controlled variable impedance unit and an overvoltage standby control unit, wherein: The voltage-controlled variable impedance unit is electrically connected to the anode and the overvoltage standby control unit respectively, and is used to conduct the current of the anode to the gate when the semiconductor device is in an overvoltage state; The overvoltage standby control unit is electrically connected to the first shutdown module, and is used to provide a shutdown control signal to the first shutdown module.

3. The overvoltage protection circuit according to claim 2, characterized in that: The overvoltage energy control module further includes: an overvoltage standby energy supply unit, one end of which is electrically connected to the gate and the overvoltage standby control unit respectively, for supplying energy to the first shutdown module.

4. The overvoltage protection circuit according to claim 1, characterized in that: The overvoltage protection circuit further includes a second shutdown module, which is electrically connected to the cathode and the first shutdown module respectively, and is used to make the gate and the cathode in a conducting state.

5. The overvoltage protection circuit according to claim 2, characterized in that: The voltage-controlled variable impedance unit includes any one or more of a Zener diode, a transient voltage suppressor diode, a breakdown diode and a thyristor.

6. The overvoltage protection circuit according to claim 1, characterized in that: The first shutdown module includes a shutdown device and / or a capacitor.

7. The overvoltage protection circuit according to claim 6, characterized in that: The first shutdown module further includes a gate driver, which is electrically connected to the shutdown device and is used to control the shutdown device to be turned on or off.

8. The overvoltage protection circuit according to claim 6, characterized in that: The turn-off device includes one of the following: HEMT and MOSFET.

9. A control method for an overvoltage protection circuit of a semiconductor device, characterized in that: The control method is used to control the overvoltage protection circuit according to any one of claims 1 to 8, and the control method comprises: Obtaining the voltage between the anode and gate of the semiconductor device; When the voltage exceeds the threshold voltage of the semiconductor device, the overvoltage energy control module that controls the overvoltage protection circuit sends a first control signal to the first shutdown module of the overvoltage protection circuit, so that the first shutdown module changes from an on state to a off state when receiving the first control signal, thereby preventing current from flowing from the gate to the cathode of the semiconductor device.

10. The control method according to claim 9, characterized in that: The control method further comprises: Obtaining the voltage between the anode and gate of the semiconductor device; When the voltage exceeds the threshold voltage of the semiconductor device, the overvoltage energy control module that controls the overvoltage protection circuit sends the first control signal to the first shutdown module, and sends the second control signal to the second shutdown module of the overvoltage protection circuit, so that the second shutdown module is in the turned-on state when receiving the second control signal, and the first shutdown module is in the turned-off state when receiving the first control signal, so as to prevent current from flowing from the gate to the cathode.

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