Driving protection circuit of power device, power chip and power device detection device

Abstract

The invention discloses a driving protection circuit of a power device, a power chip and a power device detection device. The driving protection circuit of the power device is used for protecting a driving circuit of the power device. The driving circuit is connected with the power device and used for driving the power device; the driving protection circuit of the power device comprises a control unit and a switch unit. The input end of the control unit is connected with the power device and used for detecting the gate-source voltage of the power device, the output end of the control unit is connected with the control end of the switch unit, the two ends of the switch unit are connected between the output ends of the driving circuit, and the control unit is further used for controlling the two ends of the switch unit to be conducted when the gate-source voltage is larger than preset voltage. The phenomenon that the output end of the drive circuit is damaged due to the fact that the gate-source voltage of the power device is too large can be avoided. Therefore, the maintenance cost of the high-voltage power module can be reduced, and the production efficiency of power devices is improved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of power electronics, in particular to a driving protection circuit of a power device, a power chip and a power device detection device. BACKGROUND

[0002] In the prior art, when a driving circuit is used to drive a power chip, the output end of the driving circuit is connected with the gate and the source of the power chip. When the source and the drain of the power chip have high voltage, and the power chip is short-circuited, the short-circuit phenomenon exists between the gate and the source or between the source and the drain of the power chip, so that the gate voltage of the power chip is very large, and is fed back to the output end of the driving circuit, so that the driving circuit is damaged due to bearing high voltage. When the driving circuit is integrated in a high-voltage power module, the maintenance cost of the high-voltage power module is increased. When the driving circuit is integrated in a detection device of the power chip, the production efficiency of the power chip is reduced. SUMMARY

[0003] The present application provides a driving protection circuit of a power device, a power chip and a power device detection device, which can protect the driving circuit connected with the power chip.

[0004] In a first aspect, the embodiment of the present application provides a driving protection circuit of a power device, which is used for protecting a driving circuit of the power device; the driving circuit is connected with the power device and is used for driving the power device; the driving protection circuit comprises a control unit and a switching unit;

[0005] The input end of the control unit is connected with the power device and is used for detecting the gate-source voltage of the power device; the output end of the control unit is connected with the control end of the switching unit; the two ends of the switching unit are connected between the output ends of the driving circuit; and the control unit is further used for controlling the two ends of the switching unit to be conductive when the gate-source voltage is greater than a preset voltage.

[0006] Optionally, the switching unit comprises a controllable switch; the first end of the controllable switch is connected with the first output end of the driving circuit and the gate of the power device; the second end of the controllable switch is connected with the second output end of the driving circuit and the source of the power device; the first control end of the controllable switch is connected with the first output end of the control unit; the second control end of the controllable switch is connected with the second output end of the control unit; and the control unit is used for controlling the first end and the second end of the controllable switch to be conductive when the gate-source voltage is greater than the preset voltage.

[0007] Optionally, the drive protection circuit further includes a buffer unit, wherein the first input terminal of the buffer unit is connected to the gate of the power device, the second input terminal of the buffer unit is connected to the source of the power device, the first output terminal of the buffer unit is connected to the first output terminal of the drive circuit, and the second output terminal of the buffer unit is connected to the second output terminal of the drive circuit. The buffer unit is used to increase the buffer time for the gate-source voltage to be transmitted to the output terminal of the drive circuit.

[0008] Optionally, the buffer unit includes a first inductor and a second inductor; the first inductor is connected between the gate of the power device and the first output terminal of the driving circuit, and the second inductor is connected between the source of the power device and the second output terminal of the driving circuit.

[0009] Optionally, the buffer unit includes a buffer capacitor; the buffer capacitor is connected between the first output terminal and the second output terminal of the driving circuit.

[0010] Optionally, the buffer unit further includes a current-limiting resistor; the current-limiting resistor is connected between the buffer capacitor and the output terminal of the drive circuit.

[0011] Optionally, the drive protection circuit further includes a first sampling resistor and a second sampling resistor; the first sampling resistor is connected between the first input terminal of the control unit and the gate of the power device, and the second sampling resistor is connected between the second input terminal of the control unit and the source of the power device.

[0012] Optionally, the power device includes at least one of an insulated gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, and a silicon carbide power device.

[0013] Secondly, embodiments of the present invention also provide a power chip, including a power device, a driving circuit, and a driving protection circuit for the power device described in the first aspect.

[0014] Thirdly, embodiments of the present invention also provide a power device detection device, including a driving circuit and a driving protection circuit for the power device described in the first aspect.

[0015] The technical solution of this invention connects the two ends of a switching unit to the output of a drive circuit. When the gate-source voltage of the power device exceeds a preset voltage, the control unit can control the two ends of the switching unit to connect based on the detected gate-source voltage, short-circuiting the output of the drive circuit. This avoids damage to the output of the drive circuit caused by excessive gate-source voltage. Therefore, when the drive circuit and power device are integrated into a high-voltage power module, only the power device needs maintenance, reducing the maintenance cost of the high-voltage power module. When the drive circuit is integrated into a power device testing machine, damage to the testing machine can be avoided during production testing, preventing production line downtime due to testing machine replacement, ensuring production cycle time, and improving production efficiency. Attached Figure Description

[0016] Figure 1 A schematic diagram of the driving principle of a power device provided by the prior art;

[0017] Figure 2 A schematic diagram of the structure of a drive protection circuit for a power device provided in an embodiment of the present invention;

[0018] Figure 3 A schematic diagram of the structure of another power device drive protection circuit provided in an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of the drive protection circuit for another power device provided in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0021] In the prior art, the power device M1 can be driven by the driver chip 10. Figure 1 A schematic diagram illustrating the driving principle of a power device provided by existing technology. For example... Figure 1As shown, the first output terminal GOUT+ of the driver chip 10 is connected to the gate G of the power device M1, and the second output terminal GOUT- of the driver chip 10 is connected to the source S of the power device M1. A high voltage HV exists between the source D and source S of the power device M1. When the power device M1 is short-circuited, a short circuit occurs between the drain D and gate G, or between the drain D and source S, causing the voltage between the gate G and source S of the power device M1 to become high. When this high voltage is fed back to the first output terminal GOUT+ and the second output terminal GOUT- of the driver chip 10, it exceeds the withstand voltage range of the driver chip 10, causing damage to both the first output terminal GOUT+ and the second output terminal GOUT-, i.e., damage to the driver chip 10. When the driver chip 10 and the power device M1 are combined to form a high-voltage power module, the driver chip 10 needs to be replaced simultaneously when repairing the high-voltage power module, increasing the maintenance cost of the high-voltage power module. When the driver chip 10 is integrated into the testing equipment of the power device M1, the probability of line stoppage increases during the testing process of the power device M1, reducing the production efficiency of the power device M1.

[0022] To address the aforementioned technical problems, embodiments of the present invention provide a drive protection circuit for a power device, used to protect the drive circuit of the power device. The drive circuit is connected to the power device and is used to drive the power device. Figure 2 This is a schematic diagram of a drive protection circuit for a power device provided in an embodiment of the present invention. Figure 2 As shown, the drive protection circuit includes a control unit 110 and a switching unit 120. The input terminal of the control unit 110 is connected to the power device T1 and is used to detect the gate-source voltage of the power device T1. The output terminal of the control unit 110 is connected to the control terminal K1 of the switching unit 120. The two ends of the switching unit 120 are connected between the output terminals of the drive circuit 20. The control unit 110 is also used to control the two ends of the switching unit 120 to conduct when the gate-source voltage is greater than a preset voltage.

[0023] Specifically, power device T1 can be a high-voltage power chip. A high voltage exists between the source S1 and drain D1 of power device T1. For example, the high voltage between the source S1 and drain D1 of power device T1 can be 400V-1200V. Driving circuit 20 is connected to power device T1 and is used to drive power device T1. For example, the output terminals of driving circuit 20 include a first output terminal GOUT1 and a second output terminal GOUT2. The first output terminal GOUT1 is connected to the gate G1 of power device T1, and the second output terminal GOUT2 is connected to the source S1 of power device T1. At this time, driving circuit 20 can control the gate potential and source potential of power device T1, thereby controlling the gate-source voltage difference of power device T1 to control the conduction state of power device T1.

[0024] The control unit 110 may include a first input terminal IN1 and a second input terminal IN2, which are respectively a positive voltage input terminal and a negative voltage input terminal. The first input terminal IN1 of the control unit 110 is connected to the gate G1 of the power device T1 and is used to acquire the gate potential of the power device T1. The second input terminal IN2 of the control unit 110 is connected to the source S1 of the power device T1 and is used to acquire the source potential of the power device T1. This allows the control unit 110 to determine the gate-source voltage difference of the power device T1 based on the gate potential and source potential of the power device T1. When the power device T1 is operating normally, the voltage between the gate G1 and the source S1 of the power device T1 is the gate-source voltage of the power device T1, which can be, for example, 15V. When power device T1 is short-circuited, a short circuit occurs between the drain D1 and gate G1 or between the drain D1 and source S1 of power device T1. This causes a high voltage current between the source S1 and drain D1 of power device T1 to enter the gate G1 and source S1 of power device T1, resulting in an abnormally high voltage between the gate G1 and source S1 of power device T1. At this time, the gate-source voltage of power device T1, acquired by the first input terminal IN1 and the second input terminal IN2 of control unit 110, is abnormally high. The output terminal of control unit 110 is connected to the control terminal K1 of switching unit 120, so that the control signal output by control unit 110 can control the conduction state of the two ends of switching unit 120. For example, control unit 110 can be implemented by software, such as a microcontroller. And / or, control unit 110 can be implemented by hardware, such as including voltage and current acquisition devices and logic control circuits.

[0025] The two ends of the switching unit 120 are connected between the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20, that is, the switching unit 120 is connected in series between the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20. The preset voltage can be set according to the gate-source voltage of the power device T1 during normal operation, or according to the maximum voltage that the output terminal of the drive circuit 20 can withstand. For example, the preset voltage can be set according to the maximum voltage that the output terminal of the drive circuit 20 can withstand, which is 50V. When the gate-source voltage collected by the control unit 110 is greater than the preset voltage, the control signal output by the control unit 110 can control the two ends of the switching unit 120 to conduct, so that the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20 are short-circuited through the switching unit 120, avoiding damage to the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20 caused by the relatively large gate-source voltage of the power device T1, thereby preventing damage to the drive circuit 20. When the drive circuit 20 is integrated with the power device T1 within the high-voltage power module, in the event of a short circuit in power device T1, only power device T1 needs to be repaired, reducing the maintenance cost of the high-voltage power module. When the drive circuit 20 is integrated with the testing machine for power device T1, damage to the testing machine can be avoided during production testing of power device T1, thus preventing production line downtime caused by testing machine replacement, ensuring production cycle time, and improving production efficiency.

[0026] The technical solution of this embodiment connects the two ends of a switching unit to the output of a drive circuit. When the gate-source voltage of the power device exceeds a preset voltage, the control unit can control the two ends of the switching unit to connect based on the detected gate-source voltage, thus short-circuiting the output of the drive circuit and preventing damage to the output of the drive circuit due to excessive gate-source voltage. Therefore, when the drive circuit and power device are integrated into a high-voltage power module, only the power device needs maintenance, reducing the maintenance cost of the high-voltage power module. When the drive circuit is integrated into a power device testing machine, damage to the testing machine can be avoided during production testing of the power device, thus preventing production line downtime caused by testing machine replacement, ensuring production cycle time, and improving production efficiency.

[0027] In some embodiments, the power device includes at least one of an insulated gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, and a silicon carbide power device.

[0028] Specifically, insulated-gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), and silicon carbide (SiC) power devices can all be used as high-voltage power devices to form high-voltage power modules.

[0029] Continue to refer to Figure 2 The switching unit 120 includes a controllable switch SW; the first terminal of the controllable switch SW is connected to the first output terminal GOUT1 of the drive circuit 20 and the gate G1 of the power device T1, the second terminal of the controllable switch SW is connected to the second output terminal GOUT2 of the drive circuit 20 and the source S1 of the power device T1, the first control terminal - of the controllable switch SW is connected to the first output terminal VOUT1 of the control unit 110, and the second control terminal + of the controllable switch SW is connected to the second output terminal VOUT2 of the control unit 110; the control unit 110 is used to control the first and second terminals of the controllable switch SW to conduct when the gate-source voltage is greater than a preset voltage.

[0030] Specifically, the control unit 110 may have two output terminals: a first output terminal VOUT1 and a second output terminal VOUT2. When the gate-source voltage of the power device T1 is greater than a preset voltage, the potential provided by the first output terminal VOUT1 of the control unit 110 is less than the potential provided by the second output terminal VOUT2 of the control unit 110. This causes the potential of the first control terminal of the controllable switch SW to be less than the potential of the second control terminal, thereby controlling the first and second terminals of the controllable switch SW to conduct. This causes the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20 to short-circuit, preventing damage to the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20 due to the relatively large gate-source voltage of the power device T1, thus avoiding damage to the drive circuit 20.

[0031] Continue to refer to Figure 2 The drive protection circuit also includes a first sampling resistor R1 and a second sampling resistor R2; the first sampling resistor R1 is connected between the first input terminal IN1 of the control unit 110 and the gate G1 of the power device T1, and the second sampling resistor R2 is connected between the second input terminal IN2 of the control unit 110 and the source S1 of the power device T1.

[0032] Specifically, the first sampling resistor R1 is connected between the first input terminal IN1 of the control unit 110 and the gate G1 of the power device T1, so that the first input terminal IN1 of the control unit 110 can sample the gate potential of the power device T1 by sampling the voltage and current of the first sampling resistor R1. The second sampling resistor R2 is connected between the second input terminal IN2 of the control unit 110 and the source S1 of the power device T1, so that the second input terminal IN2 of the control unit 110 can sample the source potential of the power device T1 by sampling the voltage and current of the second sampling resistor R2.

[0033] Figure 3 This is a schematic diagram of the drive protection circuit for another power device provided in an embodiment of the present invention. Figure 3 As shown, the drive protection circuit also includes a buffer unit 130. The first input terminal of the buffer unit 130 is connected to the gate G1 of the power device T1, the second input terminal of the buffer unit 130 is connected to the source S1 of the power device T1, the first output terminal of the buffer unit 130 is connected to the first output terminal GOUT1 of the drive circuit 20, and the second output terminal of the buffer unit 130 is connected to the second output terminal GOUT2 of the drive circuit 20. The buffer unit 130 is used to increase the buffer time for the gate-source voltage to be transmitted to the output terminal of the drive circuit 20.

[0034] Specifically, the buffer unit 130 is connected between the power device T1 and the output terminal of the drive circuit 20. The buffer unit 130 can buffer electrical energy. When the gate-source voltage difference between the gate G1 and the source S1 of the power device T1 is greater than a preset voltage, the buffer unit 130 can suppress the rise rate of the voltage at the output terminal of the drive circuit 20, increasing the buffer time for the output potential of the drive circuit 20 to rise to the gate-source voltage. This provides the control unit 110 with time to sample the gate-source voltage and respond according to the gate-source voltage. Before the control unit 110 controls the two ends of the switching unit 120 to conduct according to the gate-source voltage, the probability of the output terminal of the drive circuit 20 being damaged by the gate-source voltage can be reduced, improving the reliability of the drive protection circuit.

[0035] Figure 4 This is a schematic diagram of the drive protection circuit for another power device provided in an embodiment of the present invention. Figure 4 As shown, the buffer unit 130 includes a first inductor L1 and a second inductor L2; the first inductor L1 is connected between the gate G1 of the power device T1 and the first output terminal GOUT1 of the drive circuit 20, and the second inductor L2 is connected between the source S1 of the power device T1 and the second output terminal GOUT2 of the drive circuit 20.

[0036] Specifically, the first inductor L1 and the second inductor L2 are connected in series between the power device T1 and the output terminal of the drive circuit 20. When the power device T1 is short-circuited, the short-circuit current of the power device T1 is relatively large. At this time, when this short-circuit current passes through the first inductor L1 and the second inductor L2, the short-circuit current can be buffered by the first inductor L1 and the second inductor L2, which can effectively buffer the short-circuit current and ensure the buffering effect of the buffer unit 130. In addition, when the drive circuit 20 outputs a drive signal to control the state of the power device T1, the current of the drive signal provided by the drive circuit 20 is relatively small. When the drive signal passes through the first inductor L1 and the second inductor L2, the buffering effect of the first inductor L1 and the second inductor L2 on the drive signal is relatively small. Therefore, the first inductor L1 and the second inductor L2 can effectively buffer the short-circuit current of the power device T1 and reduce the impact on the drive signal provided by the drive circuit 20, thus ensuring the real-time performance of the drive circuit 20 in driving the power device T1.

[0037] Continue to refer to Figure 4 An iron core can also be provided between the first inductor L1 and the second inductor L2 to enhance the magnetic flux of the first inductor L1 and the second inductor L2, thereby improving the inductance efficiency of the first inductor L1 and the second inductor L2.

[0038] Continue to refer to Figure 4 The buffer unit 130 includes a buffer capacitor C1; the buffer capacitor C1 is connected between the first output terminal GOUT1 and the second output terminal GOUT2 of the drive circuit 20.

[0039] Specifically, the first terminal of the buffer capacitor C1 is connected to the first output terminal GOUT1 of the drive circuit 20 and the gate G1 of the power device T1, and the second terminal of the buffer capacitor C1 is connected to the second output terminal GOUT2 of the drive circuit 20 and the source S1 of the power device T1. This makes the buffer capacitor C1 connected between the output terminal of the drive circuit 20 and the power device T1, thereby suppressing the rate at which the output voltage of the drive circuit 20 rises with the gate-source voltage and increasing the buffer time for the output potential of the drive circuit 20 to rise to the gate-source voltage.

[0040] It should be noted that, Figure 4 The example shows that the buffer unit 130 includes a buffer capacitor C1, a first inductor L1, and a second inductor L2. By including both a capacitor and an inductor in the buffer unit 130, the capacitance value of the buffer capacitor C1 can be reduced while ensuring the buffering function of the buffer unit 130, thereby reducing the influence of the buffer capacitor C1 on the drive signal provided by the drive circuit 20.

[0041] Continue to refer to Figure 4The buffer unit 130 also includes a current-limiting resistor R3; the current-limiting resistor R3 is connected between the buffer capacitor C1 and the output terminal of the drive circuit 20.

[0042] Specifically, Figure 4 The example shows a current-limiting resistor R3 connected between the first output terminal GOUT1 of the drive circuit 20 and the buffer capacitor C1. In some embodiments, the current-limiting resistor R3 may also be connected between the second output terminal GOUT2 of the drive circuit 20 and the buffer capacitor C1. By setting the current-limiting resistor R3, the current on the buffer capacitor C1 can be reduced, thereby reducing the power loss on the buffer capacitor C1.

[0043] This invention also provides a power chip. The power chip includes a power device, a driving circuit, and a driving protection circuit for the power device provided in any embodiment of this invention.

[0044] Specifically, the drive circuit is connected to the power device to drive it. The input terminal of the control unit in the drive protection circuit is connected to the power device, and the output terminal is connected to the switching unit. The drive protection circuit controls the connection between the two ends of the switching unit when the gate-source voltage of the power device exceeds a preset voltage, causing a short circuit at the output terminal of the drive circuit. This prevents damage to the output terminal of the drive circuit due to excessive gate-source voltage. Therefore, in the event of a short circuit, only the power device needs repair, reducing the maintenance cost of the high-voltage power module.

[0045] This invention also provides a power device detection device, including a driving circuit and a driving protection circuit for the power device provided in any embodiment of this invention.

[0046] Specifically, the power device testing device includes a drive circuit that can perform drive testing on the power devices during the production process to ensure the yield rate of the power devices. For example, the power device testing device can be a testing machine. Simultaneously, the power device testing device also includes the drive protection circuit provided in any embodiment of the present invention. When the drive circuit performs drive testing on the power device, if a short circuit occurs in the power device, the drive circuit in the power device testing device can be protected against short circuit, thereby preventing damage to the power device testing device, avoiding production line downtime caused by replacing the power device testing device, ensuring the production cycle time of the power devices, and improving the production efficiency of the power devices.

[0047] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A drive protection circuit for a power device, characterized in that, A drive circuit for protecting the power device; the drive circuit is connected to the power device and is used to drive the power device; the drive protection circuit includes a control unit and a switching unit; The input terminal of the control unit is connected to the power device and is used to detect the gate-source voltage of the power device. The output terminal of the control unit is connected to the control terminal of the switching unit. The two ends of the switching unit are connected between the output terminals of the drive circuit. The control unit is also used to control the two ends of the switching unit to conduct when the gate-source voltage is greater than a preset voltage.

2. The drive protection circuit for the power device according to claim 1, characterized in that, The switching unit includes a controllable switch; a first terminal of the controllable switch is connected to a first output terminal of the driving circuit and the gate of the power device, a second terminal of the controllable switch is connected to a second output terminal of the driving circuit and the source of the power device, a first control terminal of the controllable switch is connected to a first output terminal of the control unit, and a second control terminal of the controllable switch is connected to a second output terminal of the control unit; the control unit is used to control the first and second terminals of the controllable switch to conduct when the gate-source voltage is greater than a preset voltage.

3. The drive protection circuit for the power device according to claim 1, characterized in that, It also includes a buffer unit, wherein the first input terminal of the buffer unit is connected to the gate of the power device, the second input terminal of the buffer unit is connected to the source of the power device, the first output terminal of the buffer unit is connected to the first output terminal of the drive circuit, and the second output terminal of the buffer unit is connected to the second output terminal of the drive circuit. The buffer unit is used to increase the buffer time for the gate-source voltage to be transmitted to the output terminal of the drive circuit.

4. The drive protection circuit for the power device according to claim 3, characterized in that, The buffer unit includes a first inductor and a second inductor; the first inductor is connected between the gate of the power device and the first output terminal of the drive circuit, and the second inductor is connected between the source of the power device and the second output terminal of the drive circuit.

5. The drive protection circuit for the power device according to claim 3 or 4, characterized in that, The buffer unit includes a buffer capacitor; the buffer capacitor is connected between the first output terminal and the second output terminal of the driving circuit.

6. The drive protection circuit for the power device according to claim 5, characterized in that, The buffer unit further includes a current-limiting resistor; the current-limiting resistor is connected between the buffer capacitor and the output terminal of the drive circuit.

7. The drive protection circuit for the power device according to claim 1, characterized in that, It also includes a first sampling resistor and a second sampling resistor; the first sampling resistor is connected between the first input terminal of the control unit and the gate of the power device, and the second sampling resistor is connected between the second input terminal of the control unit and the source of the power device.

8. The drive protection circuit for the power device according to claim 1, characterized in that, The power device includes at least one of an insulated gate bipolar transistor, a metal-oxide-semiconductor field-effect transistor, and a silicon carbide power device.

9. A power chip, characterized in that, It includes a power device, a drive circuit, and a drive protection circuit for the power device as described in any one of claims 1-8.

10. A power device testing device, characterized in that, It includes a drive circuit and a drive protection circuit for the power device as described in any one of claims 1-8.

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