Method for suppressing crosstalk of SiC MOSFET, crosstalk suppression circuit and driving circuit

Abstract

The invention discloses a method for suppressing crosstalk of a SiC MOSFET, a crosstalk suppression circuit and a driving circuit. According to the method, crosstalk peak voltage is suppressed by providing a low-impedance release path for generated Miller current. The crosstalk suppression circuit comprises a positive crosstalk suppression circuit and a negative crosstalk suppression circuit, does not need additional control signals, is simple in structure, suppresses crosstalk peak voltage in a mode of providing a low-impedance release path for generated Miller current when crosstalk occurs, and improves the crosstalk suppression efficiency while not influencing the normal switching speed of the SiC MOSFET. The SiC MOSFET can be protected from being mistakenly conducted when positive crosstalk occurs, overvoltage breakdown is avoided when negative crosstalk occurs, and the crosstalk problem is effectively restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a method for suppressing SiC MOSFET crosstalk, a crosstalk suppression circuit, and a drive circuit. Background Art

[0002] With the continuous development of the semiconductor industry and the increasing demand for power semiconductors, wide bandgap semiconductor silicon carbide power devices are widely used in the field of power electronics applications compared to Si MOSFETs due to their great advantages such as working in high temperature, high voltage, high frequency and complex radiation environments. However, in the bridge arm circuit, the high dv / dt generated by SiC MOSFET during the switching transient will cause the gate-source voltage of SiC MOSFET to have large spikes and oscillations. The existence of Miller capacitance will cause a voltage spike between the gate and source of another switch tube on the bridge arm during the on-off process of a switch tube on the bridge arm. Due to its low threshold voltage, the voltage spike is easy to exceed the turn-on voltage of SiC MOSFET, thereby causing mis-conduction of the switch tube, increasing switching losses, and in severe cases, causing the bridge arm to be directly turned on and burn the circuit; in addition, excessive negative voltage spikes will cause the gate of SiC MOSFET to bear large voltage stress, resulting in device damage. Therefore, in the bridge arm circuit, crosstalk suppression is very important for the normal operation of SiC MOSFET.

[0003] At present, the design of driving circuits for crosstalk suppression is mostly achieved from the following three aspects: 1. Changing the driving voltage level. The current methods of changing the driving voltage level mostly require adding additional control auxiliary switches, which greatly increases the complexity of control; 2. Changing the driving loop impedance. Some suppression methods achieve the purpose of crosstalk suppression by adding additional control signals, which greatly increases the complexity of circuit design; 3. Introducing closed-loop feedback variables. The design of some suppression circuits will add too many active devices and require high control accuracy. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a method, a crosstalk suppression circuit and a driving circuit that do not require additional control signals and can effectively suppress crosstalk without affecting the normal switching speed of SiC MOSFET.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for suppressing crosstalk of SiC MOSFET, when crosstalk occurs, suppresses the crosstalk spike voltage by providing a low impedance release path for the generated Miller current.

[0007] In this way, by providing a release path for the Miller current when crosstalk occurs, the normal switching speed of the SiC MOSFET can be protected from mis-conduction when positive crosstalk occurs and from overvoltage breakdown when negative crosstalk occurs, effectively suppressing the crosstalk problem. At the same time, the circuit does not require additional control signals and has a simple structure.

[0008] Preferably, when crosstalk occurs, the crosstalk voltage V gs The calculation formula is:

[0009]

[0010] C iss =C gd +C gs

[0011] Where: R g_eq is the gate drive impedance of SiC MOSFET, C iss is the input capacitance of SiC MOSFET, C gd is the gate-drain capacitance of SiCMOSFET, C gs is the gate-source capacitance of SiC MOSFET;

[0012] By reducing the gate drive impedance R of the SiC MOSFET g_eq Or increase the input capacitance of SiC MOSFET to reduce the crosstalk voltage V of SiC MOSFET gs .

[0013] A crosstalk suppression circuit for implementing the above-mentioned method for suppressing SiC MOSFET crosstalk, comprising a positive crosstalk suppression circuit and a negative crosstalk suppression circuit, wherein the positive crosstalk suppression circuit comprises a resistor R v , resistor R off , resistor R g , resistor R2, diode D1, capacitor C and PNP transistor V T , the resistor R v One end and the PNP transistor V T The emitter of the SiCMOSFET is connected to the gate of the SiCMOSFET, and the resistor R v The other end is connected to the anode of the diode D1 and the resistor R g One end and the PNP transistor V T The base of the diode D1 is connected to the cathode of the resistor R off One end of the resistor R off The other end of the resistor R g The other end of the PNP transistor is connected to VT The collector is connected to one end of the resistor R2 and one end of the capacitor C at the same time, and the other end of the resistor R2 is connected to the other end of the capacitor C and then connected to the source of the SiC MOSFET;

[0014] The negative crosstalk suppression circuit includes a resistor R and a Schottky diode D3, wherein the cathode of the Schottky diode D3 is connected to the gate of the SiC MOSFET, the anode of the Schottky diode D3 is connected to one end of the resistor R, and the other end of the resistor R is connected to the source of the SiC MOSFET.

[0015] In this way, the dvds / dt between the drain and source of the SiC MOSFET at the moment of turning on or off will act on the Miller capacitance C gd (i.e., the parasitic capacitance between the gate and drain of the SiC MOSFET) and generates a Miller current, which then flows through the SiC MOSFET gate resistance and ultimately generates a crosstalk voltage.

[0016] When the SiC MOSFET is turned on, the drain-source voltage of the SiC MOSFET rises rapidly. Due to the increase of dvds\dt, the Miller current flows from the drain end of the SiC MOSFET to the gate end, resulting in a positive voltage spike at the gate-source voltage of the SiC MOSFET. If the positive voltage spike exceeds the threshold voltage of the SiC MOSFET, it will cause mis-conduction and even burn the circuit. This is the case of forward crosstalk. When forward crosstalk occurs, the Miller current in the resistor R v The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T The threshold voltage of the PNP transistor V T conduction, so the resistance R v The resistance value should ensure that the PNP transistor V T Reliable conduction; PNP transistor V T The collector of is connected to the parallel circuit of capacitor C and resistor R2. When positive crosstalk occurs, the PNP transistor V T The branch formed by the parallel circuit of capacitor C and resistor R2 provides a low impedance release path for Miller current. Capacitor C also increases the gate-source capacitance. The role of resistor R2 is to consume the remaining energy of capacitor C after the Miller current is released. At the same time, diode D1 is turned on, R off With R g The parallel connection reduces the gate resistance of the SiC MOSFET. As a result, the forward crosstalk suppression circuit achieves the purpose of suppressing the forward crosstalk by providing a low-impedance release path for the Miller current and by reducing the gate resistance and increasing the gate capacitance.

[0017] When the SiC MOSFET is turned off, the drain-source voltage of the SiC MOSFET decreases rapidly, dvds\dt decreases, and the Miller current flows from the gate end of the SiC MOSFET to the drain end, causing a negative voltage spike in the gate-source voltage of the SiC MOSFET. If the negative voltage spike exceeds the maximum negative voltage that the SiC MOSFET can withstand, the SiC MOSFET will be broken down, damaging the device. This is the case of negative crosstalk. When negative crosstalk occurs in the negative crosstalk suppression circuit of this solution, the direction of the Miller current is opposite to the current direction when positive crosstalk occurs. At this time, the resistor R v The voltage drop does not reach the PNP transistor V T Threshold voltage, PNP transistor V T When the device is turned off, the Schottky diode D3 is turned on, and the series branch with the resistor R clamps the gate-source voltage of the SiC MOSFET. The resistor R has a small resistance value, which provides a low-impedance path for the Miller current during reverse crosstalk.

[0018] Preferably, the forward crosstalk suppression circuit further includes a resistor R1 and a Schottky diode D2, wherein the anode of the Schottky diode D2 is connected to the gate of the SiC MOSFET, and the cathode of the Schottky diode D2 is connected to the PNP transistor V T The emitter of the resistor R1 is connected to the emitter of the PNP transistor V T The base of the resistor R1 is connected to the base of the resistor R v and the resistor R g between.

[0019] In this way, the PNP transistor V T The emitter of the PNP transistor is connected to the Schottky diode D2, which is used to prevent the PNP transistor V T The emitter is broken down, and the PNP transistor V T The base of is connected to resistor R1, which is used to suppress the PNP transistor V T High frequency interference at the base.

[0020] A driving circuit for suppressing crosstalk of SiC MOSFET, comprising a DC power supply V DC , load inductance L s , load resistance R s , an upper bridge arm structure and a lower bridge arm structure, wherein the upper bridge arm structure is connected to the DC power supply V DC The positive terminal and the load inductance L s The lower bridge arm structure is connected to the DC power supply V DC The negative terminal and the load inductance L s The upper bridge arm structure includes a MOS tube S 1-H、MOS tube S 2-H , upper tube forward drive voltage V 1-H , upper tube reverse drive voltage V 2-H , switch tube Q -H and the upper crosstalk suppression circuit, the upper crosstalk suppression circuit is used to -H The forward crosstalk and reverse crosstalk are suppressed, and the lower bridge arm structure includes a MOS tube S 1-L 、MOS tube S 2-L , the lower tube forward drive voltage V 1-L , lower tube reverse drive voltage V 2-L , switch tube Q -L and is provided with the above-mentioned lower crosstalk suppression circuit, the lower crosstalk suppression circuit is used to -L The forward crosstalk and reverse crosstalk are suppressed.

[0021] In this way, when the switch tube Q -H When turned on, the switch tube Q -L The drain-source voltage of the switch tube Q increases rapidly. As dvds\dt increases, the Miller current flows from the switch tube Q -L The drain end flows to the gate end, causing the switch tube Q -L The gate-source voltage of the switch tube Q -L If the threshold voltage of the switch tube Q is too high, it will cause mis-conduction and even burn out the circuit. -H When turned off, the switch tube Q -L The drain-source voltage of the switch tube Q decreases rapidly, dvds\dt decreases, and the Miller current flows from the switch tube Q -L The gate end flows to the drain end, causing the switch tube Q -L The gate-source voltage of the switch tube Q -L The maximum negative pressure will cause the switch tube to break down, damaging the device. -H At the moment of turn-on and turn-off, the lower crosstalk suppression circuit has a great influence on the switching tube Q -L The forward and reverse crosstalk can be suppressed.

[0022] Similarly, in the switch tube Q -L At the moment of turn-on and turn-off, the upper crosstalk suppression circuit has a great influence on the switching tube Q -H The forward crosstalk and reverse crosstalk are suppressed.

[0023] Preferably, the switch tube Q -H The drain terminal is connected to the DC power supply V DC The positive electrode of the switch tube Q -H The source and the load inductance L s One end of the MOS tube S1-H The drain and the upper tube forward drive voltage V 1-H The positive electrode of the upper tube is connected to the positive drive voltage V 1-H The negative electrode is connected to the reverse drive voltage V 2-H The positive electrode and the switch tube Q -H The source connection of the upper tube reverse drive voltage V 2-H The negative electrode of the MOS tube S 2-H The source of the MOS tube S 2-H The drain of the MOS tube S 1-H The source connection of

[0024] The upper crosstalk suppression circuit includes a positive upward crosstalk suppression circuit and a negative upward crosstalk suppression circuit. The positive upward crosstalk suppression circuit includes a resistor R v-H , resistor R off-H , resistor R g-H , resistor R 2-H 、Diode D 1-H , capacitor C -H and PNP transistor V T-H , the resistor R v-H One end and the PNP transistor V T-H The emitter of the switch tube Q -H The gate connection, the resistor R v-H The other end of the diode D 1-H The anode, the resistor R g-H One end and the PNP transistor V T-H The base of the diode D 1-H The cathode and the resistor R off-H One end of the resistor R off-H The other end is connected to the MOS tube S 1-H The source of the MOS tube S 2-H The drain and the resistor R g-H The other end of the PNP transistor is connected to V T-H The collector of the resistor R 2-H One end and the capacitor C -H One end of the resistor R 2-H The other end and the capacitor C -H The other end is then connected to the switch tube Q -H The source connection of

[0025] The negative upward crosstalk suppression circuit includes a resistor R -H and Schottky diode D 3-H , the Schottky diode D 3-HThe cathode of the switch tube Q -H The gate connection of the Schottky diode D 3-H The anode and the resistor R -H One end of the resistor R -H The other end of the switch tube Q -H Source connection.

[0026] In this way, for the forward crosstalk suppression of the upper bridge arm, the lower bridge arm switch tube Q -L During the turn-on transient, the upper bridge arm switch tube Q -H Keep off, then the switch tube Q -H The Miller current flows through the driving resistor R v-H When the resistor R v-H The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T-H The threshold voltage of the PNP transistor is turned on and no additional control signal is required. T-H With capacitor C -H and resistor R 2-H The parallel circuits are connected in series, and the circuit formed increases the Q of the switch tube -H The gate-source capacitance and the release path for the Miller current are provided by the resistor R 2-H After the Miller current is released, the capacitor C is consumed. -H The remaining energy, at this time the resistance R v-H Because the PNP transistor V T-H is turned on and short-circuited; at the same time, diode D 1-H On, resistance R off-H With resistor R g-H The parallel connection reduces the gate resistance of the drive circuit. The forward crosstalk of the upper bridge arm is due to the reduction of the gate impedance of the drive circuit and the Q -H The gate-source capacitance is suppressed and the Schottky diode D 3-H Due to the reverse bias characteristic, this branch does not conduct during forward crosstalk.

[0027] For the negative crosstalk suppression of the upper bridge arm, the lower bridge arm switch tube Q -L During the turn-off transient, the upper bridge arm switch tube Q -H Keep it off. At this time, the direction of Miller current is opposite to the current direction when forward crosstalk occurs. At this time, the resistance R v-H The voltage drop does not reach the PNP transistor V T-H The threshold voltage of the PNP transistor V T-H Turn off, Schottky diode D 3-H conduction, and the resistor R -H The series branch will switch the switch tube Q -H The gate-source voltage is clamped, and the resistor R -HThe small resistance provides a low impedance path for Miller current.

[0028] Preferably, the forward crosstalk suppression circuit further includes a resistor R 1-H and Schottky diode D 2-H , the Schottky diode D 2-H The anode and the switch tube Q -H The gate connection of the Schottky diode D 2-H The cathode of the PNP transistor V T-H The emitter connection, the resistor R 1-H One end of the PNP transistor V T-H The base connection, the resistor R 1-H The other end is connected to the resistor R v-H and the resistor R g-H between.

[0029] In this way, the PNP transistor V T-H The emitter of the Schottky diode D 2-H Connected, Schottky diode D 2-H Used to prevent the PNP transistor V T-H The emitter is broken down, and the PNP transistor V T-H The base and resistor R 1-H Connected, resistor R 1-H Its function is to suppress the PNP transistor V T-H High frequency interference at the base.

[0030] Preferably, the switch tube Q -L The source and the DC power supply V DC The negative electrode of the switch tube Q -L The drain and the load inductance L s One end of the MOS tube S 1-L The drain and the lower tube forward drive voltage V 1-L The positive electrode is connected to the lower tube forward drive voltage V 1-L The negative electrode is connected to the reverse drive voltage V 2-L The positive electrode and the switch tube Q -L The source connection of the lower tube reverse drive voltage V 2-L The negative electrode of the MOS tube S 2-L The source of the MOS tube S 2-L The drain of the MOS tube S 1-L The source connection of

[0031] The downward crosstalk suppression circuit includes a positive downward crosstalk suppression circuit and a negative downward crosstalk suppression circuit. The positive downward crosstalk suppression circuit includes a resistor R v-L , resistor Roff-H , resistor R g-L , resistor R 2-L 、Diode D 1-L , capacitor C -L and PNP transistor V T-L , the resistor R v-L One end and the PNP transistor V T-L The emitter of the switch tube Q -L The gate connection, the resistor R v-L The other end of the diode D 1-L The anode, the resistor R g-L One end and the PNP transistor V T-L The base of the diode D 1-L The cathode and the resistor R off-L One end of the resistor R off-L The other end is connected to the MOS tube S 1-L The source of the MOS tube S 2-L The drain and the resistor R g-L The other end of the PNP transistor is connected to V T-L The collector of the 2-L One end and the capacitor C -L One end of the resistor R 2-L The other end and the capacitor C -L The other end is then connected to the switch tube Q -L The source connection of

[0032] The negative downward crosstalk suppression circuit includes a resistor R -L and Schottky diode D 3-L , the Schottky diode D 3-L The cathode of the switch tube Q -L The gate connection of the Schottky diode D 3-L The anode and the resistor R -L One end of the resistor R -L The other end of the switch tube Q -L Source connection.

[0033] In this way, for the forward crosstalk suppression of the lower bridge arm, the upper bridge arm switch tube Q -H During the turn-on transient, the lower bridge arm switch tube Q -L Keep off, then the switch tube Q -L The Miller current flows through the driving resistor R v-L When the resistor R v-L The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T-LThe threshold voltage of the PNP transistor is turned on and no additional control signal is required. T-L With capacitor C -L and resistor R 2-L The parallel circuits are connected in series, and the circuit formed increases the Q of the switch tube -L The gate-source capacitance and the release path for the Miller current are provided by the resistor R 2-L After the Miller current is released, the capacitor C is consumed. -L The remaining energy, at this time the resistance R v-L Because the PNP transistor V T-L is turned on and short-circuited; at the same time, diode D 1-L On, resistance R off-L With resistor R g-L The parallel connection reduces the gate resistance of the drive circuit. The forward crosstalk of the lower bridge arm is due to the reduction of the gate impedance of the drive circuit and the Q -L The gate-source capacitance is suppressed and the Schottky diode D 3-L Due to the reverse bias characteristic, this branch does not conduct during forward crosstalk.

[0034] For the negative crosstalk suppression of the lower bridge arm, the upper bridge arm switch tube Q -H During the turn-off transient, the lower bridge arm switch tube Q -L Keep it off. At this time, the direction of Miller current is opposite to the current direction when forward crosstalk occurs. At this time, the resistance R v-L The voltage drop does not reach the PNP transistor V T-L The threshold voltage of the PNP transistor V T-L Shutdown, Schottky diode D 3-L conduction, and the resistor R -L The series branch will switch the switch tube Q -L The gate-source voltage is clamped, and the resistor R -L The small resistance provides a low impedance path for Miller current.

[0035] Preferably, the forward downward crosstalk suppression circuit further includes a resistor R 1-L and Schottky diode D 2-L , the Schottky diode D 2-L The anode and the switch tube Q -L The gate connection of the Schottky diode D 2-L The cathode of the PNP transistor V T-L The emitter connection, the resistor R 1-L One end of the PNP transistor V T-L The base connection, the resistor R 1-L The other end is connected to the resistor R v-L and the resistor R g-L between.

[0036] In this way, the PNP transistor V T-L The emitter of the Schottky diode D 2-L Connected, Schottky diode D 2-L Used to prevent the PNP transistor V T-L The emitter is broken down, and the PNP transistor V T-L The base and resistor R 1-L Connected, resistor R 1-L Its function is to suppress the PNP transistor V T-L High frequency interference at the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 An equivalent circuit diagram of a crosstalk problem when SiC MOSFET is turned on in the method for suppressing SiC MOSFET crosstalk of the present invention;

[0038] Figure 2 A circuit diagram of a crosstalk suppression circuit of the present invention;

[0039] Figure 3 A circuit diagram of a driving circuit for suppressing SiC MOSFET crosstalk according to the present invention;

[0040] Figure 4 A suppression path diagram of the forward crosstalk of the lower bridge arm structure in the driving circuit for suppressing the crosstalk of SiC MOSFET according to the present invention;

[0041] Figure 5 A suppression path diagram of negative crosstalk of the lower bridge arm structure in the driving circuit for suppressing crosstalk of SiC MOSFET according to the present invention;

[0042] Figure 6 The working waveform diagram of SiC MOSFET in the driving circuit for suppressing SiC MOSFET crosstalk of the present invention;

[0043] Figure 7 A circuit simulation diagram of a driving circuit for suppressing SiC MOSFET crosstalk according to the present invention;

[0044] Figure 8 A curve diagram showing the forward crosstalk voltage spike suppression condition using the crosstalk suppression circuit of the present invention;

[0045] Fig. 9 A curve diagram showing the suppression of negative crosstalk voltage spikes by the crosstalk suppression circuit of the present invention;

[0046] Fig.10 This is a curve diagram of the forward crosstalk voltage spike when the crosstalk suppression circuit is not used;

[0047] Fig.11This is a curve diagram of the negative crosstalk voltage spike when the crosstalk suppression circuit is not used. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0049] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In this embodiment, a method for suppressing crosstalk of SiC MOSFET is provided. When crosstalk occurs, a low-impedance release path is provided for the generated Miller current to suppress the crosstalk spike voltage.

[0051] In this way, by providing a release path for the Miller current when crosstalk occurs, the normal switching speed of the SiC MOSFET can be protected from mis-conduction when positive crosstalk occurs and from overvoltage breakdown when negative crosstalk occurs, effectively suppressing the crosstalk problem. At the same time, the circuit does not require additional control signals and has a simple structure.

[0052] When the SiC MOSFET is turned on, the equivalent circuit diagram of the drive circuit is shown in the attached figure. Figure 1 As shown in the figure, according to the equivalent circuit diagram, when crosstalk occurs, the crosstalk voltage V gs The calculation formula is:

[0053]

[0054] C iss =C gd +C gs

[0055] Where: R g_eq is the gate drive impedance of SiC MOSFET, C iss is the input capacitance of SiC MOSFET, C gd is the gate-drain capacitance of SiCMOSFET, C gs is the gate-source capacitance of SiC MOSFET;

[0056] By reducing the gate drive impedance R of the SiC MOSFET g_eq Or increase the input capacitance of SiC MOSFET to reduce the crosstalk voltage V of SiC MOSFET gs .

[0057] In this specific embodiment, a crosstalk suppression circuit is also provided to implement the above-mentioned method for suppressing SiC MOSFET crosstalk, as shown in the attached Figure 2 As shown, it includes a positive crosstalk suppression circuit and a negative crosstalk suppression circuit, wherein the positive crosstalk suppression circuit includes a resistor R v , resistor R off , resistor R g , resistor R2, diode D1, capacitor C, PNP transistor V T , a resistor R1 and a Schottky diode D2, wherein the anode of the Schottky diode D2 is connected to the gate of the SiC MOSFET, and the cathode of the Schottky diode D2 is connected to the PNP transistor V T The emitter of the resistor R1 is connected to the emitter of the PNP transistor V T The base of the resistor R1 is connected to the base of the resistor Rv and the resistor R g Between, the resistor R v One end and the PNP transistor V T The emitter of the SiC MOSFET is connected to the gate of the SiC MOSFET. v The other end is connected to the anode of the diode D1 and the resistor R g One end and the PNP transistor V T The base of the diode D1 is connected to the cathode of the resistor R off One end of the resistor R off The other end of the resistor R g The other end of the PNP transistor is connected to V T The collector of the SiC MOSFET is connected to one end of the resistor R2 and one end of the capacitor C at the same time, and the other end of the resistor R2 is connected to the other end of the capacitor C and then connected to the source of the SiC MOSFET;

[0058] The negative crosstalk suppression circuit includes a resistor R and a Schottky diode D3, wherein the cathode of the Schottky diode D3 is connected to the gate of the SiC MOSFET, the anode of the Schottky diode D3 is connected to one end of the resistor R, and the other end of the resistor R is connected to the source of the SiC MOSFET.

[0059] In this way, the dvds / dt between the drain and source of the SiC MOSFET at the moment of turning on or off will act on the Miller capacitance C gd (i.e., the parasitic capacitance between the gate and drain of the SiC MOSFET) and generates a Miller current, which then flows through the SiC MOSFET gate resistance and ultimately generates a crosstalk voltage.

[0060] When the SiC MOSFET is turned on, the drain-source voltage of the SiC MOSFET rises rapidly. Due to the increase of dvds\dt, the Miller current flows from the drain end of the SiC MOSFET to the gate end, resulting in a positive voltage spike at the gate-source voltage of the SiC MOSFET. If the positive voltage spike exceeds the threshold voltage of the SiC MOSFET, it will cause mis-conduction and even burn the circuit. This is the case of forward crosstalk. When forward crosstalk occurs, the Miller current in the resistor R v The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T The threshold voltage of the PNP transistor V T conduction, so the resistance R v The resistance value should ensure that the PNP transistor V T Reliable conduction; PNP transistor V TThe emitter of the PNP transistor is connected to the Schottky diode D2, which is used to prevent the PNP transistor V T The emitter is broken down, and the PNP transistor V T The base of is connected to resistor R1, which is used to suppress the PNP transistor V T High-frequency interference of the base, PNP transistor V T The collector of is connected to the parallel circuit of capacitor C and resistor R2. When positive crosstalk occurs, the PNP transistor V T The branch formed by the parallel circuit of capacitor C and resistor R2 provides a low impedance release path for Miller current. Capacitor C also increases the gate-source capacitance. The role of resistor R2 is to consume the remaining energy of capacitor C after the Miller current is released. At the same time, diode D1 is turned on, R off With R g The parallel connection reduces the gate resistance of the SiC MOSFET. As a result, the forward crosstalk suppression circuit achieves the purpose of suppressing the forward crosstalk by providing a low-impedance release path for the Miller current and by reducing the gate resistance and increasing the gate capacitance.

[0061] When the SiC MOSFET is turned off, the drain-source voltage of the SiC MOSFET decreases rapidly, dvds\dt decreases, and the Miller current flows from the gate end of the SiC MOSFET to the drain end, causing a negative voltage spike in the gate-source voltage of the SiC MOSFET. If the negative voltage spike exceeds the maximum negative voltage that the SiC MOSFET can withstand, the SiC MOSFET will be broken down, damaging the device. This is the case of negative crosstalk. When negative crosstalk occurs in the negative crosstalk suppression circuit of this solution, the direction of the Miller current is opposite to the current direction when positive crosstalk occurs. At this time, the resistor R v The voltage drop does not reach the PNP transistor V T Threshold voltage, PNP transistor V T When the device is turned off, the Schottky diode D3 is turned on, and the series branch with the resistor R clamps the gate-source voltage of the SiC MOSFET. The resistor R has a small resistance value, which provides a low-impedance path for the Miller current during reverse crosstalk.

[0062] In this specific embodiment, the crosstalk suppression circuit of this solution is applied to a synchronous BUCK circuit for further explanation, as shown in the attached Figure 3 The circuit diagram of the crosstalk suppression circuit of the present invention is shown, including a DC power supply V DC , load inductance L s , load resistance R s , an upper bridge arm structure and a lower bridge arm structure, wherein the upper bridge arm structure is connected to the DC power supply V DC The positive terminal and the load inductance L sThe lower bridge arm structure is connected to the DC power supply V DC The negative terminal and the load inductance L s The upper bridge arm structure includes a MOS tube S 1-H 、MOS tube S 2-H , upper tube forward drive voltage V 1-H , upper tube reverse drive voltage V 2-H , switch tube Q -H And the above crosstalk suppression circuit, the switch tube Q -H The junction capacitances are C gs-H , C gd-H and C ds-H The upper crosstalk suppression circuit is used to suppress the switch tube Q -H The forward crosstalk and reverse crosstalk are suppressed, and the lower bridge arm structure includes a MOS tube S 1-L 、MOS tube S 2-L , the lower tube forward drive voltage V 1-L , lower tube reverse drive voltage V 2-L , switch tube Q -L With the above-mentioned lower crosstalk suppression circuit, the switch tube Q -L The junction capacitances are C gs-L , C gd-L and C ds-L The lower crosstalk suppression circuit is used to suppress the switch tube Q -L The forward crosstalk and reverse crosstalk are suppressed.

[0063] In this way, when the switch tube Q -H When turned on, the switch tube Q -L The drain-source voltage of the switch tube Q increases rapidly. As dvds\dt increases, the Miller current flows from the switch tube Q -L The drain end flows to the gate end, causing the switch tube Q -L The gate-source voltage of the switch tube Q -L If the threshold voltage of the switch tube Q is too high, it will cause mis-conduction and even burn out the circuit. -H When turned off, the switch tube Q -L The drain-source voltage of the switch tube Q decreases rapidly, dvds\dt decreases, and the Miller current flows from the switch tube Q -L The gate end flows to the drain end, causing the switch tube Q -L The gate-source voltage of the switch tube Q -L The maximum negative pressure will cause the switch tube to break down, damaging the device. -H At the moment of turn-on and turn-off, the lower crosstalk suppression circuit has a great influence on the switching tube Q -L The forward crosstalk and reverse crosstalk are suppressed.

[0064] Similarly, in the switch tube Q -L At the moment of turn-on and turn-off, the upper crosstalk suppression circuit has a great influence on the switching tube Q -H The forward crosstalk and reverse crosstalk are suppressed.

[0065] In this specific embodiment, the switch tube Q -L The source and the DC power supply V DC The negative electrode of the switch tube Q -L The drain and the load inductance L s One end of the MOS tube S 1-L The drain and the lower tube forward drive voltage V 1-L The positive electrode is connected to the lower tube forward drive voltage V 1-L The negative electrode is connected to the reverse drive voltage V 2-L The positive electrode and the switch tube Q -L The source connection of the lower tube reverse drive voltage V 2-L The negative electrode of the MOS tube S 2-L The source of the MOS tube S 2-L The drain of the MOS tube S 1-L The source connection of

[0066] The downward crosstalk suppression circuit includes a positive downward crosstalk suppression circuit and a negative downward crosstalk suppression circuit. The positive downward crosstalk suppression circuit includes a resistor R v-L , resistor R off-H , resistor R g-L , resistor R 2-L 、Diode D 1-L , capacitor C -L and PNP transistor V T-L , resistor R 1-L and Schottky diode D 2-L , the Schottky diode D 2-L The anode and the switch tube Q -L The gate connection of the Schottky diode D 2-L The cathode of the PNP transistor V T-L The emitter connection, the resistor R 1-L One end of the PNP transistor V T-L The base connection, the resistor R 1-L The other end is connected to the resistor R v-L and the resistor R g-L Between, the resistor R v-L One end and the PNP transistor V T-L The emitter of the switch tube Q -L The gate connection, the resistor R v-LThe other end of the diode D 1-L The anode, the resistor R g-L One end and the PNP transistor V T-L The base of the diode D 1-L The cathode and the resistor R off-L One end of the resistor R off-L The other end is connected to the MOS tube S 1-L The source of the MOS tube S 2-L The drain and the resistor R g-L The other end of the PNP transistor is connected to V T-L The collector of the resistor R 2-L One end and the capacitor C -L One end of the resistor R 2-L The other end and the capacitor C -L The other end is then connected to the switch tube Q -L The source connection of

[0067] The negative downward crosstalk suppression circuit includes a resistor R -L and Schottky diode D 3-L , the Schottky diode D 3-L The cathode of the switch tube Q -L The gate connection of the Schottky diode D 3-L The anode and the resistor R -L One end of the resistor R -L The other end of the switch tube Q -L Source connection.

[0068] In this way, for the forward crosstalk suppression of the lower bridge arm, the upper bridge arm switch tube Q -H During the turn-on transient, the lower bridge arm switch tube Q -L Keep off, if attached Figure 4 As shown, at this time, the switch tube Q -L The Miller current flows through the driving resistor R v-L When the resistor R v-L The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T-L The threshold voltage of the PNP transistor is turned on and no additional control signal is required. T-L With capacitor C -L and resistor R 2-L The parallel circuits are connected in series, and the circuit formed increases the Q of the switch tube -L The gate-source capacitance of the Schottky diode D 2-L Used to prevent the PNP transistor V T-L The emitter is broken down, the resistor R1-L Its function is to suppress the PNP transistor V T-L High frequency interference of the base, resistor R 2-L After the Miller current is released, the capacitor C is consumed. -L The remaining energy, at this time the resistance R v-L Because the PNP transistor V T-L is turned on and short-circuited; at the same time, diode D 1-L On, resistance R off-L With resistor R g-L The parallel connection reduces the gate resistance of the drive circuit. The forward crosstalk of the lower bridge arm is due to the reduction of the gate impedance of the drive circuit and the Q -L The gate-source capacitance is suppressed and the Schottky diode D 3-L Due to the reverse bias characteristic, this branch does not conduct during forward crosstalk.

[0069] For the negative crosstalk suppression of the lower bridge arm, the upper bridge arm switch tube Q -H During the turn-off transient, the lower bridge arm switch tube Q -L Keep it off. At this time, the direction of Miller current is opposite to the current direction when forward crosstalk occurs. At this time, the resistance R v-L The voltage drop does not reach the PNP transistor V T-L The threshold voltage of the PNP transistor V T-L Shut down, as attached Figure 5 As shown, the Schottky diode D 3-L conduction, and the resistor R -L The series branch will switch the switch tube Q -L The gate-source voltage is clamped, and the resistor R -L The small resistance provides a low impedance path for Miller current.

[0070] In this specific embodiment, the switch tube Q -H The drain terminal is connected to the DC power supply V DC The positive electrode of the switch tube Q -H The source and the load inductance L s One end of the MOS tube S 1-H The drain and the upper tube forward drive voltage V 1-H The positive electrode of the upper tube is connected to the positive drive voltage V 1-H The negative electrode is connected to the reverse drive voltage V 2-H The positive electrode and the switch tube Q -H The source connection of the upper tube reverse drive voltage V 2-H The negative electrode of the MOS tube S 2-H The source of the MOS tube S 2-H The drain of the MOS tube S 1-H The source connection of

[0071] The upper crosstalk suppression circuit includes a positive upward crosstalk suppression circuit and a negative upward crosstalk suppression circuit. The positive upward crosstalk suppression circuit includes a resistor R v-H , resistor R off-H , resistor R g-H , resistor R 2-H 、Diode D 1-H , capacitor C -H and PNP transistor V T-H , resistor R 1-H and Schottky diode D 2-H , the Schottky diode D 2-H The anode and the switch tube Q -H The gate connection of the Schottky diode D 2-H The cathode of the PNP transistor V T-H The emitter connection, the resistor R 1-H One end of the PNP transistor V T-H The base connection, the resistor R 1-H The other end is connected to the resistor R v-H and the resistor R g-H Between, the resistor R v-H One end and the PNP transistor V T-H The emitter of the switch tube Q -H The gate connection, the resistor R v-H The other end of the diode D 1-H The anode, the resistor R g-H One end and the PNP transistor V T-H The base of the diode D 1-H The cathode and the resistor R off-H One end of the resistor R off-H The other end is connected to the MOS tube S 1-H The source of the MOS tube S 2-H The drain and the resistor R g-H The other end of the PNP transistor is connected to V T-H The collector of the resistor R 2-H One end and the capacitor C -H One end of the resistor R 2-H The other end and the capacitor C -H The other end is then connected to the switch tube Q -H The source connection of

[0072] The negative upward crosstalk suppression circuit includes a resistor R -H and Schottky diode D 3-H, the Schottky diode D 3-H The cathode of the switch tube Q -H The gate connection of the Schottky diode D 3-H The anode and the resistor R -H One end of the resistor R -H The other end of the switch tube Q -H Source connection.

[0073] In this way, for the forward crosstalk suppression of the upper bridge arm, the lower bridge arm switch tube Q -L During the turn-on transient, the upper bridge arm switch tube Q -H Keep off, then the switch tube Q -H The Miller current flows through the driving resistor R v-H When the resistor R v-H The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T-H The threshold voltage of the PNP transistor is turned on and no additional control signal is required. T-H With capacitor C -H and resistor R 2-H The parallel circuits are connected in series, and the circuit formed increases the Q of the switch tube -H The gate-source capacitance of the Schottky diode D 2-H Used to prevent the PNP transistor V T-H The emitter is broken down, the resistor R 1-H Its function is to suppress the PNP transistor V T-H High frequency interference of the base, resistor R 2-H After the Miller current is released, the capacitor C is consumed. -H The remaining energy, at this time the resistance R v-H Because the PNP transistor V T-H is turned on and short-circuited; at the same time, diode D 1-H On, resistance R off-H With resistor R g-H The parallel connection reduces the gate resistance of the drive circuit. The forward crosstalk of the upper bridge arm is due to the reduction of the gate impedance of the drive circuit and the Q -H The gate-source capacitance is suppressed and the Schottky diode D 3-H Due to the reverse bias characteristic, this branch does not conduct during forward crosstalk.

[0074] For the negative crosstalk suppression of the upper bridge arm, the lower bridge arm switch tube Q -L During the turn-off transient, the upper bridge arm switch tube Q -H Keep it off. At this time, the direction of Miller current is opposite to the current direction when forward crosstalk occurs. At this time, the resistance R v-H The voltage drop does not reach the PNP transistor V T-HThe threshold voltage of the PNP transistor V T-H Turn off, Schottky diode D 3-H conduction, and the resistor R -H The series branch will switch the switch tube Q -H The gate-source voltage is clamped, and the resistor R -H The small resistance provides a low impedance path for Miller current.

[0075] Next, combine the switch tube Q -H And the switch tube Q -L The working waveform is further described as shown in the attached Figure 6 As shown, the details are as follows:

[0076] [t0-t1]: Switching tube Q -H Completely shut down, the switch tube Q -L Fully turned on, the load current flows through the switch tube Q -L channel, no crosstalk occurs and the crosstalk suppression circuit does not work.

[0077] [t1-t2]: Switching tube Q -H Completely shut down, the lower tube reverse drive voltage V 2-L C gs_L Reverse charging, switch tube Q _L Start to shut down. At this time, the load current flows through the switch tube Q _L The body diode is used for commutation.

[0078] [t2-t3]: Switching tube Q _H And the switch tube Q _L Completely shut down, the bridge arm is in the dead zone state.

[0079] [t3-t4]: Upper tube forward drive voltage V 1_H C gs_H To charge, switch tube Q _H Start to conduct, the switch tube Q _L dvds\dt rises rapidly, and the gate-source capacitance C gs_L A positive voltage spike is generated, and the Miller current flows through the resistor R c_L The voltage on the right is positive and the voltage on the left is negative, reaching the PNP transistor V T_L The threshold voltage is turned on and the capacitor C _L and resistor R2 _L The branch formed by the parallel circuit provides a release path for the Miller current. The capacitor C _L Increased switch Q _L The gate-source capacitance, resistance R _2 After the Miller current is released, the capacitor C is consumed. _L The remaining energy realizes forward crosstalk suppression, while the diode D 1_LOn, resistance R off_L With the driving resistor R g_L In parallel, the driving resistance impedance is reduced and the forward crosstalk is suppressed. At this time, the load current flows through the switch tube Q _H The channel.

[0080] [t4-t5]: Switching tube Q _H Fully turned on, the switch tube Q _L Completely shut down. At this time, the load current flows through the switch tube Q _H The channel.

[0081] [t5-t6]: Upper tube reverse drive voltage V 2_H C gs_H Reverse charging, switch tube Q _H Start to turn off, switch tube Q _ L dvds\dt drops rapidly, and the gate-source capacitance C gs_L A negative voltage spike is generated, and the Miller current flows through the resistor R c_L The voltage sensed on the left is positive and on the right is negative, but it does not reach the voltage of the PNP transistor V T_L The threshold voltage is turned off, and the Schottky diode D3_L conduction, and the resistor R _L The low impedance branch provides a release path for the Miller current and clamps the negative crosstalk voltage. At this time, the load current flows through the switch tube Q _L The body diode.

[0082] [t6-t7]: Switching tube Q _H Completely shut down, the switch tube Q _L Completely turned off, the load current flows through the switch tube Q _L The body diode.

[0083] [t7-t8]: Switching tube Q _H Completely shut down, the switch tube Q _L Starts to conduct. At this time, the load current flows through the switch tube Q _L channel and body diode.

[0084] Simulation verification:

[0085] The SiC MOSFET uses CREE's C3M0065090D. The turn-on bias voltage of the drive circuit is +18V, and the turn-off bias voltage is 0V.

[0086] The simulation platform was built using LTspice simulation software to compare the crosstalk voltage with and without the crosstalk suppression circuit. Figure 7 When there is no crosstalk suppression circuit, the forward crosstalk voltage is about 3.9V, that is, Fig.10As shown, the negative crosstalk voltage is about -4.5V, that is Fig.11 As shown; when there is a crosstalk suppression circuit, the forward crosstalk voltage is about 1.9V, that is Figure 8 As shown, the negative crosstalk voltage is about -1.58V, that is Fig. 9 As shown in the figure, it can be seen from the simulation results that the crosstalk suppression circuit has a significant weakening effect on the positive and negative crosstalk voltage spikes.

[0087] The specific parameter settings are as follows:

[0088] parameter Numeric <![CDATA[Resistor R g / Ω]]> 28 <![CDATA[Resistor R off / Ω]]> 1 <![CDATA[Resistance R v / Ω]]> 10 <![CDATA[Resistance R1 / Ω]]> 0 <![CDATA[Resistance R2 / Ω]]> 50 Capacitance C / nF 20 Resistance R / Ω 3

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A method for suppressing SiC MOSFET crosstalk, characterized in that: When crosstalk occurs, a low impedance release path is provided for the generated Miller current to suppress the crosstalk spike voltage.

2. The method for suppressing SiC MOSFET crosstalk according to claim 1, characterized in that: When crosstalk occurs, the crosstalk voltage V gs The calculation formula is: C iss =C gd +C gs Where: R g_eq is the gate drive impedance of SiC MOSFET, C iss is the input capacitance of SiC MOSFET, C gd is the gate-drain capacitance of SiCMOSFET, C gs is the gate-source capacitance of SiC MOSFET; By reducing the gate drive impedance R of the SiC MOSFET g_eq Or increase the input capacitance of SiC MOSFET to reduce the crosstalk voltage V of SiC MOSFET gs .

3. A crosstalk suppression circuit for implementing the method for suppressing SiC MOSFET crosstalk according to claim 1, characterized in that: It includes a positive crosstalk suppression circuit and a negative crosstalk suppression circuit, wherein the positive crosstalk suppression circuit includes a resistor R v , resistor R off , resistor R g , resistor R2, diode D1, capacitor C and PNP transistor V T , the resistor R v One end and the PNP transistor V T The emitter of the SiC MOSFET is connected to the gate of the SiC MOSFET. v The other end is connected to the anode of the diode D1 and the resistor R g One end and the PNP transistor V T The base of the diode D1 is connected to the cathode of the resistor R off One end of the resistor R off The other end of the resistor R g The other end of the PNP transistor is connected to V T The collector of the SiC MOSFET is connected to one end of the resistor R2 and one end of the capacitor C at the same time, and the other end of the resistor R2 is connected to the other end of the capacitor C and then connected to the source of the SiC MOSFET; The negative crosstalk suppression circuit includes a resistor R and a Schottky diode D3, wherein the cathode of the Schottky diode D3 is connected to the gate of the SiC MOSFET, the anode of the Schottky diode D3 is connected to one end of the resistor R, and the other end of the resistor R is connected to the source of the SiC MOSFET.

4. The crosstalk suppression circuit according to claim 3, characterized in that: The forward crosstalk suppression circuit further includes a resistor R1 and a Schottky diode D2, wherein the anode of the Schottky diode D2 is connected to the gate of the SiC MOSFET, and the cathode of the Schottky diode D2 is connected to the PNP transistor V T The emitter of the resistor R1 is connected to the emitter of the PNP transistor V T The base of the resistor R1 is connected to the base of the resistor R v and the resistor R g between.

5. A driving circuit for suppressing SiC MOSFET crosstalk, characterized in that: Including DC power supply V DC , load inductance L s , load resistance R s , an upper bridge arm structure and a lower bridge arm structure, wherein the upper bridge arm structure is connected to the DC power supply V DC The positive terminal and the load inductance L s The lower bridge arm structure is connected to the DC power supply V DC The negative terminal and the load inductance L s The upper bridge arm structure includes a MOS tube S 1-H 、MOS tube S 2-H , upper tube forward drive voltage V 1-H , upper tube reverse drive voltage V 2-H , switch tube Q -H and an upper crosstalk suppression circuit, wherein the upper crosstalk suppression circuit adopts the crosstalk suppression circuit as claimed in claim 3, and the upper crosstalk suppression circuit is used to suppress the switching tube Q -H The forward crosstalk and reverse crosstalk are suppressed, and the lower bridge arm structure includes a MOS tube S 1-L 、MOS tube S 2-L , the lower tube forward drive voltage V 1-L , lower tube reverse drive voltage V 2-L , switch tube Q -L and a lower crosstalk suppression circuit, wherein the lower crosstalk suppression circuit adopts the crosstalk suppression circuit as claimed in claim 3, and the lower crosstalk suppression circuit is used to suppress the switching tube Q -L The forward crosstalk and reverse crosstalk are suppressed.

6. The driving circuit for suppressing SiC MOSFET crosstalk according to claim 5, characterized in that: The switch tube Q -H The drain terminal is connected to the DC power supply V DC The positive electrode of the switch tube Q -H The source and the load inductance L s One end of the MOS tube S 1-H The drain and the upper tube forward drive voltage V 1-H The positive electrode of the upper tube is connected to the positive drive voltage V 1-H The negative electrode is connected to the reverse drive voltage V 2-H The positive electrode and the switch tube Q -H The source connection of the upper tube reverse drive voltage V 2-H The negative electrode of the MOS tube S 2-H The source of the MOS tube S 2-H The drain of the MOS tube S 1-H The source connection of The upper crosstalk suppression circuit includes a positive upward crosstalk suppression circuit and a negative upward crosstalk suppression circuit. The positive upward crosstalk suppression circuit includes a resistor R v-H , resistor R off-H , resistor R g-H , resistor R 2-H 、Diode D 1-H , capacitor C -H and PNP transistor V T-H , the resistor R v-H One end and the PNP transistor V T-H The emitter of the switch tube Q -H The gate connection, the resistor R v-H The other end of the diode D 1-H The anode, the resistor R g-H One end and the PNP transistor V T-H The base of the diode D 1-H The cathode and the resistor R off-H One end of the resistor R off-H The other end is connected to the MOS tube S 1-H The source of the MOS tube S 2-H The drain and the resistor R g-H The other end of the PNP transistor is connected to V T-H The collector of the 2-H One end and the capacitor C -H One end of the resistor R 2-H The other end and the capacitor C -H The other end is then connected to the switch tube Q -H The source connection of The negative upward crosstalk suppression circuit includes a resistor R -H and Schottky diode D 3-H , the Schottky diode D 3-H The cathode of the switch tube Q -H The gate connection of the Schottky diode D 3-H The anode and the resistor R -H One end of the resistor R -H The other end of the switch tube Q -H Source connection.

7. The driving circuit for suppressing SiC MOSFET crosstalk according to claim 6, characterized in that: The forward crosstalk suppression circuit further includes a resistor R 1-H and Schottky diode D 2-H , the Schottky diode D 2-H The anode and the switch tube Q -H The gate connection of the Schottky diode D 2-H The cathode of the PNP transistor V T-H The emitter connection, the resistor R 1-H One end of the PNP transistor V T-H The base connection, the resistor R 1-H The other end is connected to the resistor R v-H and the resistor R g-H between.

8. The driving circuit for suppressing SiC MOSFET crosstalk according to claim 5, characterized in that: The switch tube Q -L The source and the DC power supply V DC The negative electrode of the switch tube Q -L The drain and the load inductance L s One end of the MOS tube S 1-L The drain and the lower tube forward drive voltage V 1-L The positive electrode is connected to the lower tube forward drive voltage V 1-L The negative electrode is connected to the reverse drive voltage V 2-L The positive electrode and the switch tube Q -L The source connection of the lower tube reverse drive voltage V 2-L The negative electrode of the MOS tube S 2-L The source of the MOS tube S 2-L The drain of the MOS tube S 1-L The source connection of The downward crosstalk suppression circuit includes a positive downward crosstalk suppression circuit and a negative downward crosstalk suppression circuit. The positive downward crosstalk suppression circuit includes a resistor R v-L , resistor R off-H , resistor R g-L , resistor R 2-L 、Diode D 1-L , capacitor C -L and PNP transistor V T-L , the resistor R v-L One end and the PNP transistor V T-L The emitter of the switch tube Q -L The gate connection, the resistor R v-L The other end of the diode D 1-L The anode, the resistor R g-L One end and the PNP transistor V T-L The base of the diode D 1-L The cathode and the resistor R off-L One end of the resistor R off-L The other end is connected to the MOS tube S 1-L The source of the MOS tube S 2-L The drain and the resistor R g-L The other end of the PNP transistor is connected to V T-L The collector of the 2-L One end and the capacitor C -L One end of the resistor R 2-L The other end and the capacitor C -L The other end is then connected to the switch tube Q -L The source connection of The negative downward crosstalk suppression circuit includes a resistor R -L and Schottky diode D 3-L , the Schottky diode D 3-L The cathode of the switch tube Q -L The gate connection of the Schottky diode D 3-L The anode and the resistor R -L One end of the resistor R -L The other end of the switch tube Q -L Source connection.

9. The driving circuit for suppressing SiC MOSFET crosstalk according to claim 8, characterized in that: The forward downward crosstalk suppression circuit further includes a resistor R 1-L and Schottky diode D 2-L , the Schottky diode D 2-L The anode and the switch tube Q -L The gate connection of the Schottky diode D 2-L The cathode of the PNP transistor V T-L The emitter connection, the resistor R 1-L One end of the PNP transistor V T-L The base connection, the resistor R 1-L The other end is connected to the resistor R v-L and the resistor R g-L between.

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