A driving circuit for a power semiconductor device

Abstract

This application discloses a driving circuit for a power semiconductor device, including a feedforward circuit. The feedforward circuit includes a transient voltage suppressor diode, a feedforward capacitor, a first feedforward resistor, a second feedforward resistor, a first diode, and a second diode. The cathode of the transient voltage suppressor diode is connected to the drain or collector, the anode of the transient voltage suppressor diode is connected to one end of the feedforward capacitor, one end of the feedforward capacitor is connected to one end of the first feedforward resistor and the anode of the first diode, the cathode of the first diode is connected to one end of the second feedforward resistor, the other end of the second feedforward resistor is connected to the gate, the other end of the first feedforward resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to a second power supply.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of a driving circuit of a power semiconductor device, and particularly relates to a driving circuit of a power semiconductor device. BACKGROUND

[0002] At present, wide band gap semiconductor devices, such as silicon carbide metal-oxide-semiconductor field-effect transistors (MOSFETs), are used in more and more power electronic devices. However, how to safely and reliably drive the silicon carbide MOSFET becomes the key to the reliability of the power electronic device. At present, the driving circuit of the silicon carbide MOSFET is similar to that of the insulated gate bipolar transistor (IGBT), mainly including isolation, current amplification, overcurrent protection and the like, and the main difference is that the driving voltage is slightly different.

[0003] In the related art, in the silicon carbide MOSFET driving circuit, due to the parasitic inductance of the commutation loop during the turn-off process of the silicon carbide MOSFET, too fast turn-off speed will cause the device to withstand too high peak voltage and be damaged, affecting the working stability of the power semiconductor device.

[0004] CONTENT

[0005] Embodiments of the present application expect to provide a driving circuit of a power semiconductor device to improve the working stability of the power semiconductor device in the related art.

[0006] The technical solution of the present application is as follows:

[0007] A driving circuit of a power semiconductor device, the driving circuit further comprising: a feedforward circuit, the feedforward circuit comprising: a transient voltage suppression diode, a feedforward capacitor, a first feedforward resistor, a second feedforward resistor, a first diode and a second diode; wherein the cathode of the transient voltage suppression diode is connected to the drain or the collector of the power semiconductor device, the anode of the transient voltage suppression diode is connected to one end of the feedforward capacitor, the other end of the feedforward capacitor is connected to one end of the first feedforward resistor and the anode of the first diode respectively, the cathode of the first diode is connected to one end of the second feedforward resistor, the other end of the second feedforward resistor is connected to the gate of the power semiconductor device, the other end of the first feedforward resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to a second power supply of a power supply of the driving circuit; wherein,

[0008] The feedforward circuit is used to charge the gate capacitor when the power semiconductor device is turned off to reduce the rate of decrease of the gate voltage.

[0009] The feedforward circuit is also used to discharge the feedforward capacitor when the power semiconductor device is turned on.

[0010] The driving circuit for the power semiconductor device provided in this application embodiment further includes a feedforward circuit, which comprises a transient voltage suppression diode, a feedforward capacitor, a first feedforward resistor, a third feedforward resistor, a first diode, and a second diode. The cathode of the transient voltage suppression diode is connected to the drain or collector of the power semiconductor device. The anode of the transient voltage suppression diode is connected to one end of the feedforward capacitor. The other end of the feedforward capacitor is connected to one end of the first feedforward resistor and the anode of the first diode. The cathode of the first diode is connected to one end of the second feedforward resistor. The other end of the second feedforward resistor is connected to the gate of the power semiconductor device. The other end of the first feedforward resistor is connected to the cathode of the second diode. The anode of the second diode is connected to a second power supply of the driving circuit. The feedforward circuit is used to charge the gate capacitor when the power semiconductor device is turned off to reduce the rate of decrease of the gate voltage. The feedforward circuit is also used to discharge the feedforward capacitor when the power semiconductor device is turned on. That is, in this embodiment, by adding a feedforward circuit to the driving circuit, the gate capacitor of the power semiconductor device is charged through the feedforward circuit when the power semiconductor device is turned off, thereby controlling the gate voltage of the power semiconductor device being turned off. This slows down the gate voltage drop rate, thus suppressing the power semiconductor device from being damaged by voltage spikes. In addition, by discharging the feedforward capacitor when the power semiconductor device is turned on, the current on the feedforward capacitor is larger when the power semiconductor device is turned off, which can improve the charging speed of the gate capacitor when the power semiconductor device is turned off. In this way, the gate voltage drop rate of the power semiconductor device is controlled, preventing the device from being damaged by excessively high voltage spikes due to the excessively fast turn-off speed, thereby improving the operating stability of the power semiconductor device. Attached Figure Description

[0011] Figure 1 A schematic diagram of the structure of an optional power semiconductor device driving circuit provided for an embodiment of this application;

[0012] Figure 2 A schematic diagram of the structure of a driving circuit for another optional power semiconductor device provided in an embodiment of this application;

[0013] Figure 3 A schematic diagram of the structure of a driving circuit for another optional power semiconductor device provided in an embodiment of this application;

[0014] Figure 4 A schematic diagram of the structure of a driving circuit for another optional power semiconductor device provided in an embodiment of this application;

[0015] Figure 5 This is a schematic diagram illustrating an example of a driving circuit for an optional power semiconductor device provided in an embodiment of this application. Detailed Implementation

[0016] To better understand the purpose, structure, and function of this application, a method and control system for controlling an electric motor according to this application will be described in further detail below with reference to the accompanying drawings.

[0017] Embodiments of this application provide a driving circuit for a power semiconductor device. Figure 1 A schematic flowchart of an optional power semiconductor device driving circuit provided for an embodiment of this application is shown below. Figure 1 As shown, the driving circuit may include:

[0018] The feedforward circuit 100 includes: a transient voltage suppression diode 11, a feedforward capacitor 12, a first feedforward resistor 13, a second feedforward resistor 14, a first diode 15, and a second diode 16. The cathode of the transient voltage suppression diode 11 is connected to the drain or collector of the power semiconductor device; the anode of the transient voltage suppression diode 11 is connected to one end of the feedforward capacitor 12; the other end of the feedforward capacitor 12 is connected to one end of the first feedforward resistor 13 and the anode of the first diode 15; the cathode of the first diode 15 is connected to one end of the second feedforward resistor 14; the other end of the second feedforward resistor 14 is connected to the gate of the power semiconductor device; the other end of the first feedforward resistor 13 is connected to the cathode of the second diode 16; and the anode of the second diode 16 is connected to a second power supply of the power supply for the drive circuit.

[0019] The feedforward circuit 100 is used to charge the gate capacitor when the power semiconductor device is turned off to reduce the rate of decrease of the gate voltage.

[0020] The feedforward circuit 100 is also used to discharge the feedforward capacitor 12 when the power semiconductor device is turned on.

[0021] Currently, in related technologies, during the turn-off process of power semiconductor devices, due to the parasitic inductance in the commutation circuit, excessively fast turn-off speeds can cause the power semiconductor devices to withstand excessively high peak voltages, leading to damage and affecting the operational stability of the power semiconductor devices. This application provides a feedforward circuit 100, which, as described in the embodiment, [details about the feedforward circuit 100]. Figure 1The structure of the feedforward circuit 100 is as follows: one port is the cathode of the transient voltage suppression diode 11, which is connected to the drain or collector of the power semiconductor device; another port is one end of the second feedforward resistor 14, which is connected to the gate of the power semiconductor device; and the third port is the anode of the second diode 16, which is connected to the second power supply.

[0022] It should be noted that the anode of the second diode 16 is connected to the second power supply of the driving circuit. The second diode 16 can be connected to the positive terminal or the negative terminal of the second power supply. This embodiment of the application does not specifically limit this.

[0023] based on Figure 1 The feedforward circuit 100, taking a silicon carbide MOSFET as an example of a power semiconductor device, when the silicon carbide MOSFET is turned off, the drain-source voltage of the silicon carbide MOSFET exceeds the breakdown voltage of the transient voltage suppression diode 11. At this time, the current flows through the feedforward capacitor 12, the first diode 15 and the second feedforward resistor 14 to charge the gate capacitor, which slows down the rate of decrease of the gate capacitor, thereby suppressing the magnitude of the drain-source voltage and preventing the silicon carbide MOSFET from being damaged by excessively high peak voltage.

[0024] In addition, when the silicon carbide MOSFET is turned on, if there is a voltage on the feedforward capacitor 12, the current when charging the gate capacitor will be smaller. The excessively small current will affect the charging speed of the feedforward capacitor 12, thus failing to effectively suppress the rate of decrease of the gate voltage. To prevent this from happening, when the silicon carbide MOSFET is turned on, the feedforward capacitor 12 is discharged through the transient voltage suppression diode 11, the silicon carbide MOSFET, the second power supply, the second diode 16, and the first feedforward resistor 13, so as to quickly charge the gate capacitor when the silicon carbide MOSFET is turned off.

[0025] In other words, by charging the gate capacitor when the power semiconductor device is turned off and discharging the feedforward capacitor 12 when it is turned on, the gate voltage drop rate is suppressed, preventing the device from being damaged by excessively high peak voltages due to the excessively fast turn-off speed, thereby improving the operating stability of the power semiconductor device.

[0026] When the power semiconductor device is a MOSFET or a silicon carbide MOSFET, the cathode of the transient voltage suppression diode 11 is connected to the drain of the MOSFET or the silicon carbide MOSFET. When the power semiconductor device is an IGBT, the cathode of the transient voltage suppression diode 11 is connected to the collector of the IGBT.

[0027] In addition to the possibility of damage due to excessively high peak voltages during turn-off, power semiconductor devices also suffer from gate voltage oscillations in their drive circuits. This increases switching losses, leads to false turn-on or false turn-off, and affects the operational stability of the power semiconductor devices. To improve the operational stability of power semiconductor devices… Figure 2 A schematic diagram of another optional power semiconductor device provided in this application embodiment is shown below. Figure 2 As shown, in an optional embodiment, the driving circuit includes a resonant circuit 200, which includes a resonant resistor 21, a resonant inductor 22, and a resonant capacitor 23. The resonant resistor 21 and the resonant inductor 22 are connected in series to form a series circuit. One end of the series circuit is connected to the output terminal of the isolation device of the driving circuit, and the other end of the series circuit is connected to the input terminal of the amplifier circuit of the driving circuit and one end of the resonant capacitor 23, respectively. The other end of the resonant capacitor 23 is connected to the reference ground of the power supply.

[0028] The resonant circuit 200 is in an underdamped state and is used to output a reference voltage for the amplifier circuit; wherein, the reference voltage is a voltage with a preset rate of change.

[0029] In other words, the resonant circuit 200 is placed between the isolation device and the amplifier circuit, so that the output of the resonant circuit 200 is the input voltage of the amplifier circuit, i.e. the reference voltage. By operating the resonant circuit 200 in an underdamped state, the output of the resonant circuit 200 obtains a reference voltage with a preset rate of change.

[0030] By adding the aforementioned resonant circuit 200, the reference voltage of the amplifier circuit can be adjusted according to the various components of the resonant circuit 200 to obtain a reference voltage with a controllable rate of change. This eliminates the oscillation of the gate voltage by controlling the reference voltage of the amplifier circuit, thereby improving the working stability of the power semiconductor device.

[0031] It should be noted that the aforementioned power semiconductor device can be a MOSFET, a silicon carbide MOSFET, or an IGBT. Here, the embodiments of this application do not specifically limit it.

[0032] The aforementioned isolation device can be an optical isolation device, a capacitive isolation device, or a magnetic field isolation device. However, this application does not specifically limit the type of isolation device.

[0033] The aforementioned feedforward circuit 100 primarily reduces the rate of gate voltage decrease by charging the feedforward capacitor 12 when the power semiconductor device is turned off. Based on this, in order to further slow down the rate of gate voltage decrease, Figure 3 A schematic diagram of the structure of a driving circuit for another optional power semiconductor device provided in this application embodiment is shown below.Figure 3 As shown, in an optional embodiment, the feedforward circuit 100 further includes: a transistor 31, a third diode 32, a third feedforward resistor 33, and a fourth feedforward resistor 34; wherein,

[0034] The third feedforward resistor 33 is positioned between the first feedforward resistor 13 and the second diode 16. The base of the transistor 31 is connected to the junction of the first feedforward resistor 13 and the third feedforward resistor 33. The collector of the transistor 31 is connected to the positive terminal of the first power supply. The emitter of the transistor 31 is connected to the cathode of the second diode 16. One end of the fourth feedforward resistor 34 is connected to the anode of the third diode 32. The other end of the fourth feedforward resistor 34 is connected to the emitter of the transistor 31. The cathode of the third diode 32 is connected to the input terminal of the amplifier circuit.

[0035] The feedforward circuit 100 is used to charge the resonant capacitor 23 after the current amplified by the transistor 31 flows through the fourth feedforward resistor 34 and the third diode 32 when the power semiconductor device is turned off, so as to reduce the rate of drop of the reference voltage.

[0036] It is understandable that a transistor 31 is added to the feedforward circuit 100. This transistor 31 is used to amplify the base current when the power semiconductor device is turned off. The amplified current flows through the fourth feedforward resistor 34 and the third diode 32 and then flows to the resonant capacitor 23, thereby charging the resonant capacitor 23. This slows down the rate of decrease of the reference voltage, and thus slows down the rate of decrease of the gate voltage, thereby preventing the power semiconductor device from being damaged by excessively high peak voltage.

[0037] To enable transistor 31 to amplify the base current, in one optional embodiment, the feedforward circuit further includes a fourth diode, the anode of which is connected to the base of the transistor, and the cathode of which is connected to the collector of the transistor; wherein,

[0038] The fourth diode is used to clamp the base voltage of the transistor to the power supply voltage of the first power supply.

[0039] In other words, by adding a fourth diode to the feedforward circuit 100, specifically, by adding the fourth diode between the base and collector of the transistor 31, the fourth diode is used to clamp the base voltage of the transistor 31 to the voltage of the first power supply, thereby enabling the transistor 31 to conduct and amplify the current flowing through the base, thereby realizing the charging of the resonant capacitor.

[0040] To prevent excessively high gate voltage from causing damage to power semiconductor devices, Figure 4 A schematic diagram of the structure of another optional semiconductor power device driving circuit provided in the embodiments of this application is shown below. Figure 4As shown, in an optional embodiment, the resonant circuit 200 further includes: a voltage regulator circuit 41; one end of the voltage regulator circuit 41 is connected to the input terminal of the amplifier circuit, and the other end of the voltage regulator circuit 41 is connected to a reference ground; wherein,

[0041] The voltage regulator circuit 41 is used to clamp the reference voltage so that the reference voltage falls within a preset voltage range.

[0042] Here, a voltage regulator circuit 41 is set between the input terminal of the amplifier circuit and the reference ground to clamp the reference voltage of the amplification path within a preset voltage range. In this way, by clamping the reference voltage of the amplifier circuit, the excessive power consumption caused by the excessive gate voltage of the power semiconductor device and the risk of damage to the power semiconductor device due to the peak voltage can be prevented.

[0043] To clamp the reference voltage, in one optional embodiment, the voltage regulator circuit 41 includes: a first Zener diode and a second Zener diode; wherein,

[0044] The anode of the first Zener diode is connected to the anode of the second Zener diode, the cathode of the first Zener diode is connected to the input terminal of the amplifier circuit, and the cathode of the second Zener diode is connected to the reference ground.

[0045] It is understandable that a voltage regulator circuit can be formed by connecting two Zener diodes in series. For example, the anodes of the two Zener diodes are connected together, and the cathodes of the two Zener diodes are connected to the input terminal of the amplifier circuit and the reference ground, respectively. In this way, the two Zener diodes can clamp the reference voltage.

[0046] In practical applications, the reference voltage is usually clamped to (1.05-1.1) times the power supply voltage, which can be either the first power supply voltage or the second power supply voltage.

[0047] In order to make the reference voltage a reference voltage with a preset rate of change, the values ​​of resonant resistor 21, resonant capacitor 23 and resonant inductor 23 can be set as needed. In an optional embodiment, the capacitance value of resonant capacitor 23 is positively correlated with the ratio of the gate capacitance of the power semiconductor device to the amplification factor of the amplifier circuit.

[0048] In other words, as can be seen from the structure of the driving circuit provided in the embodiments of this application, the angular frequency of the resonant circuit 200 is proportional to the rate of change of the reference voltage. Therefore, the rate of change of the reference voltage can be controlled by controlling the angular frequency of the resonant circuit 200. Specifically, the magnitude of the angular frequency of the resonant circuit 200 can be determined by setting the values ​​of the resonant capacitor 23, the resonant inductor 22, and the resonant resistor 21.

[0049] Regarding the structure of the resonant circuit 200, the capacitance value of the resonant capacitor 23 is mainly related to the gate capacitance of the power semiconductor device and the amplification factor of the transistor in the amplifier circuit. Specifically, the capacitance value of the resonant capacitor 23 is positively correlated with the ratio of the gate capacitance to the amplification factor of the transistor. It can be seen that the larger the ratio of the gate capacitance of the power semiconductor device to the amplification factor of the transistor, the larger the capacitance value of the resonant capacitor 23; the smaller the gate capacitance of the power semiconductor device and the amplification factor of the transistor, the smaller the capacitance value of the resonant capacitor 23.

[0050] Regarding the inductance value of resonant inductor 22, in one optional embodiment, the inductance value of the resonant inductor is inversely correlated with the product of the square of the angular frequency of the resonant circuit and the capacitance value of the resonant capacitor.

[0051] The inductance value of the resonant circuit 200 is mainly related to the square of the angular frequency of the resonant circuit 200 and the capacitance value of the resonant capacitor 23. Specifically, the inductance value of the resonant circuit 200 is positively correlated with the product of the square of the angular frequency of the resonant circuit 200 and the capacitance value of the resonant capacitor 23. It can be seen that the larger the product of the square of the angular frequency of the resonant circuit 200 and the capacitance value of the resonant capacitor 23, the smaller the inductance value of the resonant circuit 200; conversely, the smaller the product of the square of the angular frequency of the resonant circuit 200 and the capacitance value of the resonant capacitor 23, the smaller the inductance value of the resonant circuit 200.

[0052] Regarding the resistance value of resonant resistor 21, in one optional embodiment, the resistance value of resonant resistor 21 is positively correlated with the product of the square root of the ratio of the inductance value of resonant inductor 22 to the capacitance value of resonant capacitor 23 and the damping ratio of resonant circuit 200.

[0053] Based on the structure of the resonant circuit 200, the resistance value of the resonant resistor 21 is related to the damping ratio of the resonant circuit 200, as well as the capacitance value of the resonant capacitor 23 and the inductance value of the resonant inductor 22. The square root of the ratio between the inductance value of the resonant inductor 22 and the capacitance value of the resonant capacitor 23 is calculated. The resistance value of the resonant resistor 21 is proportional to the product of the square root of the ratio and the damping ratio. Therefore, the larger the product of the square root of the ratio between the inductance value of the resonant inductor 22 and the capacitance value of the resonant capacitor 23 and the damping ratio, the larger the resistance value of the resonant resistor 21. Conversely, the smaller the product of the square root of the ratio between the inductance value of the resonant inductor 22 and the capacitance value of the resonant capacitor 23 and the damping ratio, the smaller the resistance value of the resonant resistor 21.

[0054] In addition, in order to control the reference voltage to a preset rate of change when the resonant circuit 200 is in an underdamped state, in an optional embodiment, the damping ratio of the resonant circuit 200 is greater than or equal to 0.2 and less than or equal to 0.5.

[0055] In other words, when the damping ratio of the resonant circuit 200 is between 0.2 and 0.5, the reference voltage can be controlled to a voltage with a preset rate of change, which can eliminate the oscillations present in the gate voltage and thus improve the operating stability of the power semiconductor device.

[0056] The following examples illustrate the driving circuit of the power semiconductor device described in one or more of the above embodiments.

[0057] Figure 5 A schematic diagram illustrating an example of a driving circuit for an optional power semiconductor device provided in this application embodiment, as shown below. Figure 5 As shown, the power semiconductor device is a silicon carbide MOSFET, denoted by M1. The first power supply is V1, and the second power supply is V2. The gate of M1 is connected to the output terminal of the amplifier circuit, which is a push-pull amplifier circuit composed of transistors Q1 and Q2, turn-on resistor R3, and turn-off resistor R4. The negative terminals of V1 and V2 are both connected to the reference ground of the power supply. V1 and V2 are the power supplies for the drive circuit. The source of M1 is connected to the reference ground, and the drain of M1 is connected to the lower bridge of phase U in the three-phase inverter circuit.

[0058] In addition, to improve the working stability of M1, Figure 5 The driving circuit also includes: an RLC resonant stage circuit (equivalent to the resonant circuit mentioned above) and a dv / dt feedforward control stage circuit (equivalent to the feedforward circuit mentioned above).

[0059] Vin serves as the input voltage of the resonant circuit and is the control voltage signal output by the optocoupler, ranging from -5V to +15V. The reference voltage Vref is the output voltage of the RLC resonant circuit composed of R1, L1, and C1. ZD1 and ZD2 are Zener diodes. Q1 and Q2 form the amplifier stage circuit, and R3 and R4 are the gate drive turn-on and turn-off resistors, respectively. The transient suppression diode TVS2 is used for gate protection. The transient suppression diodes TVS1, C2, D2, R5, R6, R7, Q3, D4, R2, and D1 constitute the dv / dt feedforward control stage circuit.

[0060] For RLC resonant stage circuits, the working principle is as follows:

[0061] Since the RLC resonant circuit operates in an underdamped state with a damping ratio δ between 0.2 and 0.5, the overshoot voltage of Vref is approximately 20% to 50%. ZD1 and ZD2 clamp Vref at (1.05 to 1.1) times the power supply voltage of V1 or V2. The rise and fall slopes of Vref can be determined based on the switching speed and losses of M1. Therefore, the angular frequency of the RLC resonant circuit is:

[0062]

[0063] Where, ω N δ represents the angular frequency and the damping ratio.

[0064] If Ciss is the gate capacitance of M1, and β is the amplification factor of Q1 and Q2, then

[0065] C1=(5~10)·Ciss / β (2)

[0066]

[0067] For the amplifier stage circuit (equivalent to the amplifier circuit described above), the working principle is as follows:

[0068] The amplifier stage circuit consists of Q1, Q2, R3, and R4. R3 is the gate drive turn-on resistor, used to control the turn-on time of M1; R4 is the gate drive turn-off resistor, used to control the turn-off time of M1. The input of the amplifier stage circuit is the reference voltage Vref, and Vg is the output voltage of the amplifier stage circuit, which is also the gate voltage of M1. Figure 5 As can be seen from the structure of the circuit,

[0069] Vg=Vref + Vbe (5)

[0070] Where Vbe is the base voltage of Q1 or Q2; Q1 and Q2 form a push-pull amplifier circuit, which is used to amplify the output current of the RLC resonant stage and drive M1.

[0071] For the dv / dt feedforward control stage circuit, the working principle is as follows:

[0072] If the parasitic inductance of the commutation circuit of M1 is Ls, the drain-source current is Id, the drain-source voltage is Vds, the transconductance of M1 is gm, and the gate turn-on voltage is Vth, then according to the following equation (6), when the parasitic inductance is constant, the drain-source voltage spike Vds is proportional to the rate of decrease of the gate voltage Vg.

[0073]

[0074] The dv / dt feedforward control stage circuit consists of transient suppression diodes TVS1, C2, D2, R5, R6, R7, Q3, D4, R2, and D1. When M1 is turned off, if the drain-source voltage of M1 exceeds the breakdown voltage of TVS1, current will flow through C2. Part of this current charges the gate capacitor of M1 through D2 and R5, slowing down the rate of Vg decrease. The other part provides base current to Q3 through R6. This current is amplified by Q3 and then charges C1 through R2 and D1, slowing down the rate of Vref decrease. After being amplified, Vref further slows down the rate of Vg decrease, thereby suppressing drain-source voltage spikes and preventing overvoltage of M1.

[0075] D4 clamps the base potential of Q3 to power supply V1. When M1 is turned on, C2 discharges through TVS1, M1, V2, D3, R7, and R6, thus enabling dv / dt feedback during the next turn-off. Furthermore, according to Kirchhoff's voltage law, the following equation holds:

[0076]

[0077] Where Re is the equivalent resistance of the feedback current flowing through C2 to the power supply ground, therefore the feedback current can be obtained from the following formula:

[0078]

[0079] In summary, the RLC resonant circuit in the front stage can generate a reference voltage waveform with a controllable slope, eliminating oscillation and delay. The drain dv / dt voltage feedforward circuit in the back stage can quickly adjust the gate voltage according to the drain voltage spike, thereby reducing the turn-off speed of the silicon carbide MOSFET, ensuring that the turn-off voltage spike is within a reasonable range, and effectively preventing device overvoltage.

[0080] The driving circuit for the power semiconductor device provided in this application embodiment further includes a feedforward circuit, which comprises a transient voltage suppression diode, a feedforward capacitor, a first feedforward resistor, a second feedforward resistor, a first diode, and a second diode. The cathode of the transient voltage suppression diode is connected to the drain or collector of the power semiconductor device. The anode of the transient voltage suppression diode is connected to one end of the feedforward capacitor. The other end of the feedforward capacitor is connected to one end of the first feedforward resistor and the anode of the first diode. The cathode of the first diode is connected to one end of the second feedforward resistor. The other end of the second feedforward resistor is connected to the gate of the power semiconductor device. The other end of the first feedforward resistor is connected to the cathode of the second diode. The anode of the second diode is connected to a second power supply of the driving circuit. The feedforward circuit is used to charge the gate capacitor when the power semiconductor device is turned off to reduce the rate of decrease of the reference voltage. The feedforward circuit is also used to discharge the feedforward capacitor when the power semiconductor device is turned on. That is, in this embodiment, by adding a feedforward circuit to the driving circuit, the gate capacitor of the power semiconductor device is charged through the feedforward circuit when the power semiconductor device is turned off, thereby controlling the gate voltage of the power semiconductor device being turned off. This slows down the gate voltage drop rate, thus suppressing the power semiconductor device from being damaged by voltage spikes. In addition, by discharging the feedforward capacitor when the power semiconductor device is turned on, the current on the feedforward capacitor is larger when the power semiconductor device is turned off, which can improve the charging speed of the gate capacitor when the power semiconductor device is turned off. In this way, the gate voltage drop rate of the power semiconductor device is controlled, preventing the device from being damaged by excessively high voltage spikes due to the excessively fast turn-off speed, thereby improving the operating stability of the power semiconductor device.

[0081] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0082] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0083] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application.

Claims

1. A drive circuit of a power semiconductor device, characterized by, The drive circuit comprises a feedforward circuit, the feedforward circuit comprising a transient voltage suppression diode, a feedforward capacitor, a first feedforward resistor, a second feedforward resistor, a first diode and a second diode; wherein the cathode of the transient voltage suppression diode is connected to the drain or the collector of the power semiconductor device, the anode of the transient voltage suppression diode is connected to one end of the feedforward capacitor, the other end of the feedforward capacitor is connected to one end of the first feedforward resistor and the anode of the first diode respectively, the cathode of the first diode is connected to one end of the second feedforward resistor, the other end of the second feedforward resistor is connected to the gate of the power semiconductor device, the other end of the first feedforward resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to a second power supply of a power supply of the drive circuit; wherein The feedforward circuit is used to charge the gate capacitance to reduce the falling rate of the gate voltage when the power semiconductor device is turned off; The feedforward circuit is also used to discharge the feedforward capacitor when the power semiconductor device is turned on.

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