Crosstalk suppression driving circuit of silicon carbide MOSFET bridge circuit and power supply equipment

Abstract

The utility model relates to a crosstalk suppression driving circuit of a silicon carbide MOSFET bridge circuit and power supply equipment. The crosstalk suppression driving circuit comprises an upper bridge driving module, an upper bridge crosstalk suppression module, a lower bridge driving module and a lower bridge crosstalk suppression module. The upper bridge driving module is respectively connected with the upper bridge crosstalk suppression module and the upper bridge arm, and the upper bridge crosstalk suppression module is also connected with the upper bridge arm; the lower bridge driving module is connected with the lower bridge crosstalk suppression module and the lower bridge arm, and the lower bridge crosstalk suppression module is further connected with the lower bridge arm. Each crosstalk suppression module and the corresponding bridge arm share a turn-off signal and a turn-on signal, and there is no need to additionally add a detection or control circuit to control the crosstalk suppression module. Each crosstalk suppression module is connected with the corresponding bridge arm in the turn-off process of the corresponding bridge arm, so that the forward driving crosstalk and the negative driving crosstalk of the silicon carbide MOSFET can be suppressed; and each crosstalk suppression module is automatically disconnected with the corresponding bridge arm before the corresponding bridge arm is conducted, so that the conduction loss of the bridge arm can be reduced, and the circuit efficiency is prevented from being reduced.

Description

Technical Field

[0001] This utility model relates to the field of power electronic drive, and in particular to a crosstalk suppression drive circuit and power supply device for silicon carbide MOSFET bridge circuit. Background Technology

[0002] In high-frequency applications, parasitic parameters introduced by the silicon carbide MOSFET's own packaging and stray parameters introduced by PCB traces become non-negligible. Due to these parameters, drive crosstalk occurs between the upper and lower bridge arms of silicon carbide MOSFETs in various power electronic converter topologies with bridge connections. The gate-source turn-on voltage of a silicon carbide MOSFET is typically below 2V, and the gate-source negative voltage is within -8V. The activation of the upper bridge switch in a silicon carbide MOSFET can cause positive or negative pulse fluctuations in the gate-source voltage of the non-activated lower bridge arm silicon carbide MOSFET. Positive crosstalk voltages may cause a false turn-on of a silicon carbide MOSFET that should not be activated, while negative crosstalk voltages may break down the gate-source electrodes of the power device, damaging it.

[0003] The existing solutions to the crosstalk problem in silicon carbide MOSFETs include the following:

[0004] The first approach uses an integrated chip with built-in active Miller clamping to detect whether the drive crosstalk voltage reaches the crosstalk threshold, thereby clamping the silicon carbide MOSFET drive. However, this solution only clamps positive crosstalk; it cannot effectively detect negative drive crosstalk, failing to clamp the negative drive crosstalk of the silicon carbide MOSFET. This ultimately leads to damage to the gate and source of the silicon carbide MOSFET due to excessively high negative voltage, severely impacting circuit reliability. Using active Miller clamping requires additional circuitry to detect positive drive crosstalk voltage, increasing system control complexity. Furthermore, using an integrated chip with built-in active clamping also results in high circuit cost.

[0005] 2. Adding an RC passive snubber network between the drain and source of the silicon carbide MOSFET to suppress drive crosstalk. This method mainly reduces the crosstalk between the upper and lower transistors by adjusting the parameters of the resistors and capacitors in the RC passive snubber network to match the parameters of the drive circuit. This suppresses the voltage change rate of the drive circuit and absorbs voltage spikes. However, because the RC passive snubber network is directly connected in parallel between the drain and source of the silicon carbide MOSFET, with the high-frequency switching of the silicon carbide MOSFET, all the energy stored in the capacitor is released to the resistors and the silicon carbide MOSFET, causing severe heating of the resistors and requiring the use of higher power resistors. Furthermore, the power consumption of the resistors further reduces the overall efficiency. The RC passive snubber network has limited absorption and buffering effect on high-frequency voltage spikes at the switching node. Therefore, the indirect suppression of drive crosstalk using this method is not significant. It also occupies space on the PCB, reducing PCB space utilization, increasing cost, and lowering reliability. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a crosstalk suppression drive circuit and power supply device for a silicon carbide MOSFET bridge circuit.

[0007] The technical solution adopted by this utility model to solve its technical problem is: to provide a crosstalk suppression driving circuit for a silicon carbide MOSFET bridge circuit, wherein the bridge circuit includes an upper bridge arm and a lower bridge arm, the upper bridge arm includes an upper bridge silicon carbide MOSFET, and the lower bridge arm includes a lower bridge silicon carbide MOSFET.

[0008] The crosstalk suppression driving circuit includes: an upper bridge driving module, an upper bridge crosstalk suppression module, a lower bridge driving module, and a lower bridge crosstalk suppression module;

[0009] The upper bridge drive module is connected to the upper bridge crosstalk suppression module and the upper bridge arm respectively, and the upper bridge crosstalk suppression module is also connected to the upper bridge arm; the lower bridge drive module is connected to the lower bridge crosstalk suppression module and the lower bridge arm respectively, and the lower bridge crosstalk suppression module is also connected to the lower bridge arm;

[0010] The upper bridge drive module is used to output an upper bridge turn-off signal or an upper bridge turn-on signal; the lower bridge drive module is used to output a lower bridge turn-off signal or a lower bridge turn-on signal.

[0011] The upper bridge crosstalk suppression module is configured to: connect to the upper bridge arm according to the upper bridge turn-off signal before the upper bridge arm is turned off according to the upper bridge turn-on signal; disconnect from the upper bridge arm according to the upper bridge turn-on signal before the upper bridge arm is turned on according to the upper bridge turn-on signal; and suppress positive drive crosstalk caused by the lower bridge arm being turned on and negative drive crosstalk caused by the lower bridge arm being turned off when the upper bridge arm is turned off.

[0012] The lower bridge crosstalk suppression module is configured to: connect to the lower bridge arm according to the lower bridge turn-off signal before the lower bridge arm is turned off according to the lower bridge turn-on signal; disconnect from the lower bridge arm according to the lower bridge turn-on signal before the lower bridge arm is turned on according to the lower bridge turn-on signal; and suppress positive drive crosstalk caused by the upper bridge arm being turned on and negative drive crosstalk caused by the upper bridge arm being turned off when the lower bridge arm is turned off.

[0013] Furthermore, the upper bridge crosstalk suppression module includes an upper bridge suppression control unit and an upper bridge crosstalk suppression unit. The upper bridge suppression control unit is connected to the upper bridge drive module and the upper bridge crosstalk suppression unit, respectively, and the upper bridge crosstalk suppression unit is connected to the upper bridge arm.

[0014] The upper bridge suppression control unit controls the upper bridge crosstalk suppression unit to disconnect or connect with the upper bridge arm according to the upper bridge turn-off signal or the upper bridge turn-on signal; the upper bridge crosstalk suppression unit is used to suppress the positive drive crosstalk and negative drive crosstalk of the upper bridge arm;

[0015] The lower bridge crosstalk suppression module includes a lower bridge suppression control unit and a lower bridge crosstalk suppression unit. The lower bridge suppression control unit is connected to the lower bridge drive module and the lower bridge crosstalk suppression unit, respectively. The lower bridge crosstalk suppression unit is connected to the lower bridge arm.

[0016] The lower bridge suppression control unit controls the lower bridge crosstalk suppression unit to disconnect or connect with the lower bridge arm according to the lower bridge turn-off signal or the lower bridge turn-on signal; the lower bridge crosstalk suppression unit is used to suppress the positive drive crosstalk and negative drive crosstalk of the lower bridge arm.

[0017] Furthermore, the upper bridge crosstalk suppression unit includes a capacitor C5, a switch Q3, and a resistor R6;

[0018] One end of capacitor C5 is connected to the gate of the upper bridge silicon carbide MOSFET, and the other end of capacitor C5 is connected to the drain of the switching transistor Q3. Resistor R6 is connected between the gate and source of the switching transistor Q3. The gate of the switching transistor Q3 is also connected to the upper bridge suppression control unit, and the source of the switching transistor Q3 is also connected to the source of the upper bridge silicon carbide MOSFET.

[0019] The lower bridge crosstalk suppression unit includes a capacitor C6, a switch Q4, and a resistor R13;

[0020] One end of the capacitor C6 is connected to the gate of the lower-bridge silicon carbide MOSFET, and the other end of the capacitor C6 is connected to the drain of the switching transistor Q4. The resistor R13 is connected between the gate and the source of the switching transistor Q4. The gate of the switching transistor Q4 is also connected to the lower-bridge suppression control unit, and the source of the switching transistor Q4 is also connected to the source of the lower-bridge silicon carbide MOSFET.

[0021] Furthermore, the upper bridge suppression control unit includes resistors R1, R2, R3, R4, R5 and a switching transistor Q9;

[0022] One end of resistor R1 is connected to the first input power supply voltage. The other end of resistor R1 is connected to the drain of the switching transistor Q9 and one end of resistor R2. The other end of resistor R2 is connected to the upper bridge drive module and one end of resistor R3. The other end of resistor R3 is connected to the gate of the switching transistor Q9. Resistor R4 is connected between the gate and drain of the switching transistor Q9. The source of the switching transistor Q9 is connected to the upper bridge crosstalk suppression unit through resistor R5.

[0023] The lower bridge suppression control unit includes resistors R8, R9, R10, R11, R12, and a switching transistor Q10;

[0024] One end of resistor R8 is connected to the second input power supply voltage. The other end of resistor R8 is connected to the drain of the switching transistor Q10 and one end of resistor R9. The other end of resistor R9 is connected to the lower bridge drive module and one end of resistor R10. The other end of resistor R10 is connected to the gate of the switching transistor Q10. Resistor R11 is connected between the gate and drain of the switching transistor Q10. The source of the switching transistor Q10 is connected to the lower bridge crosstalk suppression unit through resistor R12.

[0025] Furthermore, the upper bridge drive module includes an upper bridge power supply unit, an upper bridge drive control unit, and an upper bridge speed regulation unit;

[0026] The upper bridge drive control unit is connected to the upper bridge power supply unit, the upper bridge crosstalk suppression module and the upper bridge speed control unit respectively, and is used to convert the drive power provided by the upper bridge power supply unit into the upper bridge turn-off signal or the upper bridge turn-on signal; the upper bridge speed control unit is also connected to the upper bridge arm, and is used to adjust the speed at which the upper bridge arm is turned on or off.

[0027] The lower bridge drive module includes a lower bridge power supply unit, a lower bridge drive control unit, and a lower bridge speed regulation unit.

[0028] The lower bridge drive control unit is connected to the lower bridge power supply unit, the lower bridge crosstalk suppression module and the lower bridge speed control unit respectively, and is used to convert the drive power provided by the lower bridge power supply unit into the lower bridge turn-off signal or the lower bridge turn-on signal; the lower bridge speed control unit is also connected to the lower bridge arm, and is used to adjust the speed at which the lower bridge arm is turned on or off.

[0029] Furthermore, the upper bridge drive control unit includes switching transistor Q5 and switching transistor Q6;

[0030] The source of the switching transistor Q5 is connected to the drain of the switching transistor Q6. The drain of the switching transistor Q5 and the source of the switching transistor Q6 are connected to the upper bridge power supply unit. The source of the switching transistor Q5 is also connected to the gate of the upper bridge silicon carbide MOSFET, which is connected through the upper bridge speed control unit.

[0031] The lower bridge drive control unit includes switching transistors Q7 and Q8;

[0032] The source of the switching transistor Q7 is connected to the drain of the switching transistor Q8. The drain of the switching transistor Q7 and the source of the switching transistor Q8 are connected to the lower bridge power supply unit. The source of the switching transistor Q7 is also connected to the gate of the lower bridge silicon carbide MOSFET, which is connected through the lower bridge speed control unit.

[0033] Furthermore, the upper bridge power supply unit includes an upper bridge DC power supply, capacitor C1, and capacitor C2;

[0034] The positive output terminal of the upper bridge DC power supply is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to the negative output terminal of the upper bridge DC power supply, one end of the capacitor C1 is also connected to the drain of the switching transistor Q5, the other end of the capacitor C1 is also connected to the source of the upper bridge silicon carbide MOSFET, and the other end of the capacitor C2 is also connected to the source of the switching transistor Q6.

[0035] The lower bridge power supply unit includes a lower bridge DC power supply, capacitor C3, and capacitor C4.

[0036] The positive output terminal of the lower bridge DC power supply is connected to one end of capacitor C3, the other end of capacitor C3 is connected to one end of capacitor C4, the other end of capacitor C4 is connected to the negative output terminal of the lower bridge DC power supply, one end of capacitor C3 is also connected to the drain of switching transistor Q7, the other end of capacitor C3 is also connected to the source of the lower bridge silicon carbide MOSFET, and the other end of capacitor C4 is also connected to the source of switching transistor Q8.

[0037] Furthermore, the upper bridge speed control unit includes resistor R7, resistor Rgh, and diode D1;

[0038] One end of the resistor Rgh is connected to the source of the switching transistor Q5 and one end of the resistor R7. The other end of the resistor Rgh is connected to the gate of the upper bridge silicon carbide MOSFET and the anode of the diode D1. The other end of the resistor R7 is connected to the cathode of the diode D1.

[0039] The lower bridge speed control unit includes resistor R14, resistor R11, and diode D2;

[0040] One end of the resistor Rgl is connected to the source of the switching transistor Q7 and one end of the resistor R14. The other end of the resistor Rgl is connected to the gate of the lower bridge silicon carbide MOSFET and the anode of the diode D2. The other end of the resistor R14 is connected to the cathode of the diode D2.

[0041] Furthermore, the drain of the upper bridge silicon carbide MOSFET is connected to the positive output terminal of the DC bus, the source of the upper bridge silicon carbide MOSFET is connected to the drain of the lower bridge silicon carbide MOSFET, and the source of the lower bridge silicon carbide MOSFET is connected to the negative output terminal of the DC bus.

[0042] A power supply device is also provided, comprising a crosstalk suppression drive circuit for a silicon carbide MOSFET bridge circuit as described in any of the preceding claims.

[0043] The present invention has the following advantages: each crosstalk suppression module shares the turn-off signal and turn-on signal with the corresponding silicon carbide MOSFET, eliminating the need for additional detection or control circuitry to control the crosstalk suppression module; each crosstalk suppression module is connected to the corresponding bridge arm during the turn-off process, which can suppress the positive drive crosstalk and negative drive crosstalk of the silicon carbide MOSFET; each crosstalk suppression module is automatically disconnected from the corresponding bridge arm before the bridge arm is turned on, which can reduce the conduction loss of the silicon carbide MOSFET and avoid reducing circuit efficiency. Attached Figure Description

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0045] Figure 1 This is a schematic diagram of a silicon carbide MOSFET bridge circuit and its driver circuit without crosstalk suppression.

[0046] Figure 2 This is a structural block diagram of an embodiment of the crosstalk suppression drive circuit of the silicon carbide MOSFET bridge circuit of this utility model.

[0047] Figure 3 This is a structural block diagram of another embodiment of the crosstalk suppression drive circuit of the silicon carbide MOSFET bridge circuit of this utility model;

[0048] Figure 4 This is a schematic diagram showing the direction of Miller current flow when suppressing positive drive crosstalk;

[0049] Figure 5 This is a schematic diagram showing the direction of Miller current flow when suppressing negative drive crosstalk. Detailed Implementation

[0050] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is constructed and operated in a specific orientation. It is only for the convenience of describing this technical solution and does not indicate that the device or component referred to must have a specific orientation; therefore, it should not be construed as a limitation of this utility model.

[0051] The crosstalk suppression drive circuit of this invention, based on a silicon carbide MOSFET bridge circuit, is applied to a bridge circuit. The bridge circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm includes an upper silicon carbide MOSFET, and the lower bridge arm includes a lower silicon carbide MOSFET. The drain of the upper silicon carbide MOSFET is connected to the positive output terminal of the DC bus Vbus, the source of the upper silicon carbide MOSFET is connected to the drain of the lower silicon carbide MOSFET, and the source of the lower silicon carbide MOSFET is connected to the negative output terminal of the DC bus Vbus.

[0052] In this embodiment, the bridge circuit is a half-bridge power circuit composed of upper and lower bridge silicon carbide MOSFETs, wherein the silicon carbide MOSFETs are NMOS transistors. Figure 1 This is a schematic diagram of a silicon carbide MOSFET bridge circuit and its driver circuit without crosstalk suppression. Figure 1 In the diagram, resistors Rdh and Rdl are the static resistances of the upper and lower bridge silicon carbide MOSFETs, respectively; capacitors Cdsh and Cdsl are the Miller capacitances of the upper and lower bridge silicon carbide MOSFETs, respectively; and capacitors Cgsh and Cgsl are the gate-source capacitances of the upper and lower bridge silicon carbide MOSFETs, respectively.

[0053] like Figure 1 As shown, the principle of drive crosstalk generation will be explained below using the lower bridge arm as an example:

[0054] The lower-bridge DC power supply, capacitors C3 and C4, switching transistors Q7 and Q8, and resistor Rgl constitute the lower-bridge driver module. This module outputs a lower-bridge turn-off signal or a lower-bridge turn-on signal to the lower-bridge silicon carbide MOSFETs in the lower-bridge arm. The lower-bridge turn-off signal is a negative voltage, while the lower-bridge turn-on signal is a positive voltage.

[0055] When the upper-bridge silicon carbide MOSFET Q1 is turned on, the voltage and current at the switching node of the lower-bridge silicon carbide MOSFET Q2 rise linearly. The capacitor Cdsl in the lower-bridge silicon carbide MOSFET Q2 charges, and the Miller current of capacitor Cdsl flows through resistor Rgl and capacitor Cgsl. The Miller current flowing through resistor Rgl generates a positive voltage, causing a positive drive voltage (positive drive crosstalk) to appear at the gate of the lower-bridge silicon carbide MOSFET Q2 during the turn-off period. When this voltage exceeds the turn-on voltage Vth of the silicon carbide MOSFET, it will cause common conduction of the upper and lower bridge arms.

[0056] When the upper-bridge silicon carbide MOSFET Q1 is turned off, the switching node voltage and current of the lower-bridge silicon carbide MOSFET Q2 decrease linearly. The capacitor Cdsl in the lower-bridge silicon carbide MOSFET Q2 discharges, and Miller current flows through resistor Rgl, capacitor Cdsl, and capacitor Cgsl, generating a negative voltage. Simultaneously, due to the parasitic lead inductance at the drain of the lower-bridge silicon carbide MOSFET Q2, a voltage oscillation spike, i.e., negative drive crosstalk, will be generated on the gate of the lower-bridge silicon carbide MOSFET Q2. When the total negative drive voltage, resulting from the voltage oscillation spike and the voltage generated by the Miller current discharge, exceeds the negative voltage value of the silicon carbide MOSFET, it will damage the gate and source of the silicon carbide MOSFET, reducing device reliability.

[0057] like Figure 2 As shown, in one embodiment, the crosstalk suppression driving circuit includes: an upper bridge driving module 11, an upper bridge crosstalk suppression module 12, a lower bridge driving module 21, and a lower bridge crosstalk suppression module 22. The upper bridge driving module 11 is connected to the upper bridge crosstalk suppression module 12 and the upper bridge arm, and the upper bridge crosstalk suppression module 12 is also connected to the upper bridge arm; the lower bridge driving module 21 is connected to the lower bridge crosstalk suppression module 22 and the lower bridge arm, and the lower bridge crosstalk suppression module 22 is also connected to the lower bridge arm.

[0058] The upper bridge driver module 11 is used to output an upper bridge off signal or an upper bridge on signal. The lower bridge driver module 21 is used to output a lower bridge off signal or a lower bridge on signal.

[0059] The upper bridge crosstalk suppression module 12 is connected to the upper bridge arm according to the upper bridge turn-off signal before the upper bridge arm is turned off according to the upper bridge turn-on signal; and disconnected from the upper bridge arm according to the upper bridge turn-on signal before the upper bridge arm is turned on according to the upper bridge turn-on signal. When the upper bridge arm is turned off, it is used to suppress the positive drive crosstalk generated by the upper bridge arm due to the lower bridge arm being turned on, and the negative drive crosstalk generated by the lower bridge arm being turned off.

[0060] The lower bridge crosstalk suppression module 22 is connected to the lower bridge arm according to the lower bridge turn-off signal before the lower bridge arm is turned off according to the lower bridge turn-on signal; and disconnected from the lower bridge arm according to the lower bridge turn-on signal before the lower bridge arm is turned on according to the lower bridge turn-on signal. When the lower bridge arm is turned off, it is used to suppress the positive drive crosstalk generated by the upper bridge arm being turned on and the negative drive crosstalk generated by the upper bridge arm being turned off.

[0061] In this embodiment, the upper and lower bridge silicon carbide MOSFETs turn off upon receiving the corresponding turn-off signal (i.e., the upper and lower bridge arms are turned off), and turn on upon receiving the corresponding turn-on signal (i.e., the upper and lower bridge arms are turned on). Each crosstalk suppression module operates accordingly based on the turn-off or turn-on signal of its respective bridge arm before the turn-off or turn-on signal reaches the silicon carbide MOSFET. During the turn-off process of the silicon carbide MOSFET, the crosstalk suppression module remains connected to the gate of the silicon carbide MOSFET according to the turn-off signal, absorbing both positive and negative drive crosstalk. Before the turn-on signal output by the drive module reaches the silicon carbide MOSFET, the crosstalk suppression module receives the turn-on signal and automatically disconnects from the gate of the silicon carbide MOSFET according to the turn-on signal, thereby reducing the conduction loss of the silicon carbide MOSFET and avoiding a decrease in circuit efficiency.

[0062] Compared to integrated chips using active Miller clamping, this solution can suppress both positive and negative drive crosstalk. Each crosstalk suppression module shares the turn-off and turn-on signals with its corresponding silicon carbide MOSFET, eliminating the need for additional detection or control circuitry to control the crosstalk suppression modules. Compared to adding an RC passive buffer absorption network for drive crosstalk suppression, this solution disconnects the crosstalk suppression module before the bridge arm turns on, reducing the conduction losses of the silicon carbide MOSFET and avoiding a decrease in circuit efficiency.

[0063] Furthermore, such as Figure 3 As shown, the upper bridge crosstalk suppression module 12 includes an upper bridge suppression control unit 121 and an upper bridge crosstalk suppression unit 122. The upper bridge suppression control unit 121 is connected to both the upper bridge drive module 11 and the upper bridge crosstalk suppression unit 122, and the upper bridge crosstalk suppression unit 122 is connected to the upper bridge arm. The upper bridge suppression control unit 121 controls the upper bridge crosstalk suppression unit 122 to disconnect or connect with the upper bridge arm according to an upper bridge turn-off signal or an upper bridge turn-on signal. The upper bridge crosstalk suppression unit 122 is used to suppress positive drive crosstalk and negative drive crosstalk of the upper bridge arm.

[0064] The lower bridge crosstalk suppression module 22 includes a lower bridge suppression control unit 221 and a lower bridge crosstalk suppression unit 222. The lower bridge suppression control unit 221 is connected to both the lower bridge drive module 21 and the lower bridge crosstalk suppression unit 222, and the lower bridge crosstalk suppression unit 222 is connected to the lower bridge arm. The lower bridge suppression control unit 221 controls the lower bridge crosstalk suppression unit 222 to disconnect or connect with the lower bridge arm according to a lower bridge turn-off signal or a lower bridge turn-on signal. The lower bridge crosstalk suppression unit 222 is used to suppress positive drive crosstalk and negative drive crosstalk of the lower bridge arm.

[0065] In this embodiment, after each bridge arm is disconnected, the crosstalk suppression unit can suppress both positive and negative drive crosstalk while remaining connected to the corresponding bridge arm, without needing to switch according to different crosstalk types.

[0066] Furthermore, the upper bridge drive module 11 includes an upper bridge power supply unit 111, an upper bridge drive control unit 112, and an upper bridge speed control unit 113. The upper bridge drive control unit 112 is connected to the upper bridge power supply unit 111, the upper bridge crosstalk suppression module 12, and the upper bridge speed control unit 113, respectively, and is used to convert the drive power provided by the upper bridge power supply unit 111 into an upper bridge turn-off signal or an upper bridge turn-on signal. The upper bridge speed control unit 113 is also connected to the upper bridge arm and is used to adjust the speed at which the upper bridge arm is turned on or off.

[0067] The lower bridge drive module 21 includes a lower bridge power supply unit 211, a lower bridge drive control unit 212, and a lower bridge speed control unit 213. The lower bridge drive control unit 212 is connected to the lower bridge power supply unit 211, the lower bridge crosstalk suppression module 22, and the lower bridge speed control unit 213, respectively, and is used to convert the drive power provided by the lower bridge power supply unit 211 into a lower bridge turn-off signal or a lower bridge turn-on signal. The lower bridge speed control unit 213 is also connected to the lower bridge arm and is used to adjust the speed at which the lower bridge arm is turned on or off.

[0068] The following describes a crosstalk suppression drive circuit for a silicon carbide MOSFET bridge circuit using a specific embodiment.

[0069] In this embodiment, the upper bridge crosstalk suppression unit 122 includes a capacitor C5, a switch Q3, and a resistor R6. One end of the capacitor C5 is connected to the gate of the upper bridge silicon carbide MOSFET, and the other end of the capacitor C5 is connected to the drain of the switch Q3. The resistor R6 is connected between the gate and source of the switch Q3. The gate of the switch Q3 is also connected to the upper bridge suppression control unit 121, and the source of the switch Q3 is also connected to the source of the upper bridge silicon carbide MOSFET.

[0070] The lower-bridge crosstalk suppression unit 222 includes a capacitor C6, a switching transistor Q4, and a resistor R13. One end of the capacitor C6 is connected to the gate of the lower-bridge silicon carbide MOSFET, and the other end of the capacitor C6 is connected to the drain of the switching transistor Q4. The resistor R13 is connected between the gate and source of the switching transistor Q4. The gate of the switching transistor Q4 is also connected to the lower-bridge suppression control unit 221, and the source of the switching transistor Q4 is also connected to the source of the lower-bridge silicon carbide MOSFET.

[0071] Specifically, capacitor C5 is used to suppress the positive and negative drive crosstalk of the upper-bridge silicon carbide MOSFET, and capacitor C6 is used to suppress the positive and negative drive crosstalk of the lower-bridge silicon carbide MOSFET. Switches Q3 and Q4 are NMOS transistors, and resistors R6 and R13 are used to protect the gate and source of switches Q3 and Q4, respectively.

[0072] In this embodiment, the upper bridge suppression control unit 121 includes resistors R1, R2, R3, R4, R5, and a switching transistor Q9. One end of resistor R1 is connected to the first input power supply voltage VCC1, and the other end of resistor R1 is connected to the drain of the switching transistor Q9 and one end of resistor R2. The other end of resistor R2 is connected to the upper bridge drive module 11 and one end of resistor R3. The other end of resistor R3 is connected to the gate of the switching transistor Q9. Resistor R4 is connected between the gate and drain of the switching transistor Q9. The source of the switching transistor Q9 is connected to the upper bridge crosstalk suppression unit 122 through resistor R5.

[0073] The lower-bridge suppression control unit 221 includes resistors R8, R9, R10, R11, R12, and a switching transistor Q10. One end of resistor R8 is connected to the second input power supply voltage VCC2, and the other end of resistor R8 is connected to the drain of switching transistor Q10 and one end of resistor R9. The other end of resistor R9 is connected to the lower-bridge drive module 21 and one end of resistor R10, and the other end of resistor R10 is connected to the gate of switching transistor Q10. Resistor R11 is connected between the gate and drain of switching transistor Q10. The source of switching transistor Q10 is connected to the lower-bridge crosstalk suppression unit 222 through resistor R12. Switches Q9 and Q10 are PMOS transistors.

[0074] In this embodiment, the upper bridge drive control unit 112 includes switching transistors Q5 and Q6. The source of switching transistor Q5 is connected to the drain of switching transistor Q6, and the drain of switching transistor Q5 and the source of switching transistor Q6 are connected to the upper bridge power supply unit 111. The source of switching transistor Q5 is also connected to the gate of the upper bridge silicon carbide MOSFET, which is connected to the upper bridge speed control unit 113. Switching transistor Q5 is an NMOS transistor, and switching transistor Q6 is a PMOS transistor. In some embodiments, transistors can also be used instead of switching transistors Q5 and Q6.

[0075] The lower-bridge drive control unit 212 includes switching transistors Q7 and Q8. The source of switching transistor Q7 is connected to the drain of switching transistor Q8. The drain of switching transistor Q7 and the source of switching transistor Q8 are connected to the lower-bridge power supply unit 211. The source of switching transistor Q7 is also connected to the gate of the lower-bridge silicon carbide MOSFET, which is connected via the lower-bridge speed control unit 213. Switching transistor Q7 is an NMOS transistor, and switching transistor Q8 is a PMOS transistor. In some embodiments, transistors can be used instead of switching transistors Q7 and Q8.

[0076] In this embodiment, the upper bridge power supply unit 111 includes an upper bridge DC power supply DC1, capacitor C1, and capacitor C2. The positive output terminal of the upper bridge DC power supply is connected to one end of capacitor C1, the other end of capacitor C1 is connected to one end of capacitor C2, the other end of capacitor C2 is connected to the negative output terminal of the upper bridge DC power supply, one end of capacitor C1 is also connected to the drain of switching transistor Q5, the other end of capacitor C1 is also connected to the source of the upper bridge silicon carbide MOSFET, and the other end of capacitor C2 is also connected to the source of switching transistor Q6.

[0077] The lower-bridge power supply unit 211 includes a lower-bridge DC power supply DC2, capacitor C3, and capacitor C4. The positive output terminal of the lower-bridge DC power supply is connected to one end of capacitor C3, the other end of capacitor C3 is connected to one end of capacitor C4, the other end of capacitor C4 is connected to the negative output terminal of the lower-bridge DC power supply, one end of capacitor C3 is also connected to the drain of switching transistor Q7, the other end of capacitor C3 is also connected to the source of the lower-bridge silicon carbide MOSFET, and the other end of capacitor C4 is also connected to the source of switching transistor Q8.

[0078] Specifically, when switch Q7 is off and switch Q8 is on, capacitor C4 discharges, providing a negative voltage to the gate of the lower-bridge silicon carbide MOSFET, thus turning off the lower-bridge silicon carbide MOSFET. When switch Q7 is on and switch Q8 is off, capacitor C3 discharges, providing a positive voltage to the gate of the lower-bridge silicon carbide MOSFET, thus turning on the lower-bridge silicon carbide MOSFET. The switching of the upper bridge arm is similar to that of the lower bridge arm and will not be described in detail here.

[0079] In this embodiment, the upper bridge speed control unit 113 includes a resistor R7, a resistor Rgh, and a diode D1. One end of the resistor Rgh is connected to the source of the switching transistor Q5 and one end of the resistor R7, the other end of the resistor Rgh is connected to the gate of the upper bridge silicon carbide MOSFET and the anode of the diode D1, and the other end of the resistor R7 is connected to the cathode of the diode D1.

[0080] The lower bridge speed control unit 213 includes resistor R14, resistor R11, and diode D2. One end of resistor R11 is connected to the source of switching transistor Q7 and one end of resistor R14. The other end of resistor R11 is connected to the gate of the lower bridge silicon carbide MOSFET and the anode of diode D2. The other end of resistor R14 is connected to the cathode of diode D2.

[0081] The following describes the specific working principle of the crosstalk suppression drive circuit of the silicon carbide MOSFET bridge circuit in this embodiment. For the working principle of the upper bridge arm, please refer to the lower bridge arm. Details are as follows:

[0082] The lower bridge drive module 21 outputs a lower bridge turn-on signal, which is a positive voltage. The lower bridge turn-on signal enters the lower bridge suppression control unit 221. Due to the combined effect of the lower bridge turn-on signal and the voltage division of the second input power supply voltage VCC2, the switch Q10 is turned off, the drive voltage of the switch Q4 drops to zero, and the switch Q4 promptly disconnects the capacitor C6. The lower bridge crosstalk suppression unit 222 automatically disconnects to avoid the presence of capacitor C6 affecting the rising edge of the drive of the lower bridge silicon carbide MOSFET, which would increase the turn-on loss of the lower bridge silicon carbide MOSFET and reduce the circuit efficiency.

[0083] like Figure 4 As shown in the diagram, the arrows indicate the direction of Miller current flow. When the upper bridge arm is on, switch Q7 is off and switch Q8 is on. The lower bridge drive module 21 outputs a lower bridge turn-off signal, maintaining the drive voltage of the lower bridge silicon carbide MOSFET Q2 in a negative state. The lower bridge silicon carbide MOSFET Q2 and the lower bridge suppression control unit 221 share this lower bridge turn-off signal. At this time, the gate-source voltage of switch Q10 is less than zero, and switch Q10 is turned on. The second input power supply voltage VCC2, after being divided by resistors, provides a drive voltage for switch Q4, and switch Q4 is turned on. Capacitor C6 is connected in parallel with the gate-source of the lower bridge silicon carbide MOSFET Q2. Due to the conduction of the upper bridge arm, the lower bridge arm switching node voltage Vds rises linearly, and the Miller capacitor in the lower bridge silicon carbide MOSFET Q2 begins to charge.

[0084] The Miller current mainly flows through three paths: capacitor Cdsl-resistor Rgl, (diode D2, resistor R14)-switch Q8, capacitor Cdsl-capacitor C6-switch Q4, and capacitor Cdsl-capacitor Cgsl. Since capacitor C6 is connected in parallel with resistor Rgl, capacitor Cgsl, resistor Rdl, resistor R14, and diode D2, and because capacitor C6 has a relatively large capacitance, its insertion effectively reduces the impedance of the lower-bridge silicon carbide MOSFET drive circuit. Simultaneously, the presence of capacitor C6 shuns the Miller current, thus suppressing forward drive crosstalk.

[0085] like Figure 5As shown in the diagram, the arrows indicate the direction of Miller current flow. When the upper bridge arm is turned off, switch Q7 is off and switch Q8 is on. The lower bridge drive module 21 outputs a lower bridge turn-off signal, maintaining the drive voltage of the lower bridge silicon carbide MOSFET Q2 in a negative state. The lower bridge silicon carbide MOSFET Q2 and the lower bridge suppression control unit 221 share this lower bridge turn-off signal. At this time, the gate-source voltage of switch Q10 is less than zero, and switch Q10 is turned on. The second input power supply voltage VCC2, after being divided by resistors, provides a drive voltage for switch Q4, and switch Q4 is turned on. Capacitor C6 is connected in parallel with the gate-source of the lower bridge silicon carbide MOSFET Q2. Due to the turn-off of the upper bridge arm, the lower bridge arm switching node voltage Vds decreases linearly, and the Miller capacitance in the lower bridge silicon carbide MOSFET Q2 begins to discharge.

[0086] The Miller current flows through three paths: switch Q8 - resistor Rgl - capacitor Cdsl, switch Q4 - capacitor C6 - capacitor Cdsl, and capacitor Cgsl - capacitor Cdsl. Since capacitor C6 is connected in parallel with resistors Rgl, Cgsl, and Rdl, and due to the relatively large capacitance of C6, its insertion effectively reduces the impedance of the lower-bridge silicon carbide MOSFET drive circuit. Simultaneously, the presence of capacitor C6 shuns the Miller current, and it effectively suppresses negative drive spike oscillations, thus mitigating negative drive crosstalk.

[0087] In this embodiment, the crosstalk suppression module and the corresponding silicon carbide MOSFET share the same signal, resulting in a simple circuit structure. No additional control circuit is needed to control the crosstalk suppression module, ensuring high reliability. When one silicon carbide MOSFET is turned on, the other remains off, and its crosstalk suppression module automatically enters the loop, reducing the impedance of the other silicon carbide MOSFET's drive loop. This effectively suppresses crosstalk affecting the drive of the other silicon carbide MOSFET during its off-state, improving the crosstalk immunity of the bridge circuit's drive loop. This crosstalk suppression drive circuit features low cost, fast response speed, and high reliability.

[0088] This utility model also provides a power supply device. In this embodiment, the power supply device includes a crosstalk suppression drive circuit for the silicon carbide MOSFET bridge circuit disclosed in any of the above embodiments.

[0089] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A crosstalk suppression driving circuit for a silicon carbide MOSFET bridge circuit, characterized in that, The bridge circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm includes an upper bridge silicon carbide MOSFET, and the lower bridge arm includes a lower bridge silicon carbide MOSFET. The crosstalk suppression driving circuit includes: an upper bridge driving module, an upper bridge crosstalk suppression module, a lower bridge driving module, and a lower bridge crosstalk suppression module; The upper bridge drive module is connected to the upper bridge crosstalk suppression module and the upper bridge arm respectively, and the upper bridge crosstalk suppression module is also connected to the upper bridge arm; the lower bridge drive module is connected to the lower bridge crosstalk suppression module and the lower bridge arm respectively, and the lower bridge crosstalk suppression module is also connected to the lower bridge arm; The upper bridge drive module is used to output an upper bridge turn-off signal or an upper bridge turn-on signal; the lower bridge drive module is used to output a lower bridge turn-off signal or a lower bridge turn-on signal. The upper bridge crosstalk suppression module is configured to: connect to the upper bridge arm according to the upper bridge turn-off signal before the upper bridge arm is turned off according to the upper bridge turn-on signal; disconnect from the upper bridge arm according to the upper bridge turn-on signal before the upper bridge arm is turned on according to the upper bridge turn-on signal; and suppress positive drive crosstalk caused by the lower bridge arm being turned on and negative drive crosstalk caused by the lower bridge arm being turned off when the upper bridge arm is turned off. The lower bridge crosstalk suppression module is configured to: connect to the lower bridge arm according to the lower bridge turn-off signal before the lower bridge arm is turned off according to the lower bridge turn-on signal; disconnect from the lower bridge arm according to the lower bridge turn-on signal before the lower bridge arm is turned on according to the lower bridge turn-on signal; and suppress positive drive crosstalk caused by the upper bridge arm being turned on and negative drive crosstalk caused by the upper bridge arm being turned off when the lower bridge arm is turned off.

2. The crosstalk suppression driving circuit for the silicon carbide MOSFET bridge circuit according to claim 1, characterized in that, The upper bridge crosstalk suppression module includes an upper bridge suppression control unit and an upper bridge crosstalk suppression unit. The upper bridge suppression control unit is connected to the upper bridge drive module and the upper bridge crosstalk suppression unit, respectively. The upper bridge crosstalk suppression unit is connected to the upper bridge arm. The upper bridge suppression control unit controls the upper bridge crosstalk suppression unit to disconnect or connect with the upper bridge arm according to the upper bridge turn-off signal or the upper bridge turn-on signal; the upper bridge crosstalk suppression unit is used to suppress the positive drive crosstalk and negative drive crosstalk of the upper bridge arm; The lower bridge crosstalk suppression module includes a lower bridge suppression control unit and a lower bridge crosstalk suppression unit. The lower bridge suppression control unit is connected to the lower bridge drive module and the lower bridge crosstalk suppression unit, respectively. The lower bridge crosstalk suppression unit is connected to the lower bridge arm. The lower bridge suppression control unit controls the lower bridge crosstalk suppression unit to disconnect or connect with the lower bridge arm according to the lower bridge turn-off signal or the lower bridge turn-on signal; the lower bridge crosstalk suppression unit is used to suppress the positive drive crosstalk and negative drive crosstalk of the lower bridge arm.

3. The crosstalk suppression driving circuit of the silicon carbide MOSFET bridge circuit according to claim 2, characterized in that, The upper bridge crosstalk suppression unit includes a capacitor C5, a switch Q3, and a resistor R6; One end of capacitor C5 is connected to the gate of the upper bridge silicon carbide MOSFET, and the other end of capacitor C5 is connected to the drain of the switching transistor Q3. Resistor R6 is connected between the gate and source of the switching transistor Q3. The gate of the switching transistor Q3 is also connected to the upper bridge suppression control unit, and the source of the switching transistor Q3 is also connected to the source of the upper bridge silicon carbide MOSFET. The lower bridge crosstalk suppression unit includes a capacitor C6, a switch Q4, and a resistor R13; One end of the capacitor C6 is connected to the gate of the lower-bridge silicon carbide MOSFET, and the other end of the capacitor C6 is connected to the drain of the switching transistor Q4. The resistor R13 is connected between the gate and the source of the switching transistor Q4. The gate of the switching transistor Q4 is also connected to the lower-bridge suppression control unit, and the source of the switching transistor Q4 is also connected to the source of the lower-bridge silicon carbide MOSFET.

4. The crosstalk suppression driving circuit of the silicon carbide MOSFET bridge circuit according to claim 2, characterized in that, The upper bridge suppression control unit includes resistors R1, R2, R3, R4, R5 and a switching transistor Q9; One end of resistor R1 is connected to the first input power supply voltage. The other end of resistor R1 is connected to the drain of the switching transistor Q9 and one end of resistor R2. The other end of resistor R2 is connected to the upper bridge drive module and one end of resistor R3. The other end of resistor R3 is connected to the gate of the switching transistor Q9. Resistor R4 is connected between the gate and drain of the switching transistor Q9. The source of the switching transistor Q9 is connected to the upper bridge crosstalk suppression unit through resistor R5. The lower bridge suppression control unit includes resistors R8, R9, R10, R11, R12, and a switching transistor Q10; One end of resistor R8 is connected to the second input power supply voltage. The other end of resistor R8 is connected to the drain of the switching transistor Q10 and one end of resistor R9. The other end of resistor R9 is connected to the lower bridge drive module and one end of resistor R10. The other end of resistor R10 is connected to the gate of the switching transistor Q10. Resistor R11 is connected between the gate and drain of the switching transistor Q10. The source of the switching transistor Q10 is connected to the lower bridge crosstalk suppression unit through resistor R12.

5. The crosstalk suppression driving circuit for the silicon carbide MOSFET bridge circuit according to claim 1, characterized in that, The upper bridge drive module includes an upper bridge power supply unit, an upper bridge drive control unit, and an upper bridge speed regulation unit. The upper bridge drive control unit is connected to the upper bridge power supply unit, the upper bridge crosstalk suppression module and the upper bridge speed control unit respectively, and is used to convert the drive power provided by the upper bridge power supply unit into the upper bridge turn-off signal or the upper bridge turn-on signal; the upper bridge speed control unit is also connected to the upper bridge arm, and is used to adjust the speed at which the upper bridge arm is turned on or off. The lower bridge drive module includes a lower bridge power supply unit, a lower bridge drive control unit, and a lower bridge speed regulation unit. The lower bridge drive control unit is connected to the lower bridge power supply unit, the lower bridge crosstalk suppression module and the lower bridge speed control unit respectively, and is used to convert the drive power provided by the lower bridge power supply unit into the lower bridge turn-off signal or the lower bridge turn-on signal; the lower bridge speed control unit is also connected to the lower bridge arm, and is used to adjust the speed at which the lower bridge arm is turned on or off.

6. The crosstalk suppression driving circuit for the silicon carbide MOSFET bridge circuit according to claim 5, characterized in that, The upper bridge drive control unit includes switching transistors Q5 and Q6; The source of the switching transistor Q5 is connected to the drain of the switching transistor Q6. The drain of the switching transistor Q5 and the source of the switching transistor Q6 are connected to the upper bridge power supply unit. The source of the switching transistor Q5 is also connected to the gate of the upper bridge silicon carbide MOSFET, which is connected through the upper bridge speed control unit. The lower bridge drive control unit includes switching transistors Q7 and Q8; The source of the switching transistor Q7 is connected to the drain of the switching transistor Q8. The drain of the switching transistor Q7 and the source of the switching transistor Q8 are connected to the lower bridge power supply unit. The source of the switching transistor Q7 is also connected to the gate of the lower bridge silicon carbide MOSFET, which is connected through the lower bridge speed control unit.

7. The crosstalk suppression driving circuit of the silicon carbide MOSFET bridge circuit according to claim 6, characterized in that, The upper bridge power supply unit includes an upper bridge DC power supply, capacitor C1, and capacitor C2. The positive output terminal of the upper bridge DC power supply is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to the negative output terminal of the upper bridge DC power supply, one end of the capacitor C1 is also connected to the drain of the switching transistor Q5, the other end of the capacitor C1 is also connected to the source of the upper bridge silicon carbide MOSFET, and the other end of the capacitor C2 is also connected to the source of the switching transistor Q6. The lower bridge power supply unit includes a lower bridge DC power supply, capacitor C3, and capacitor C4. The positive output terminal of the lower bridge DC power supply is connected to one end of capacitor C3, the other end of capacitor C3 is connected to one end of capacitor C4, the other end of capacitor C4 is connected to the negative output terminal of the lower bridge DC power supply, one end of capacitor C3 is also connected to the drain of switching transistor Q7, the other end of capacitor C3 is also connected to the source of the lower bridge silicon carbide MOSFET, and the other end of capacitor C4 is also connected to the source of switching transistor Q8.

8. The crosstalk suppression driving circuit of the silicon carbide MOSFET bridge circuit according to claim 6, characterized in that, The upper bridge speed control unit includes resistor R7, resistor Rgh, and diode D1; One end of the resistor Rgh is connected to the source of the switching transistor Q5 and one end of the resistor R7. The other end of the resistor Rgh is connected to the gate of the upper bridge silicon carbide MOSFET and the anode of the diode D1. The other end of the resistor R7 is connected to the cathode of the diode D1. The lower bridge speed control unit includes resistor R14, resistor R11, and diode D2; One end of the resistor Rgl is connected to the source of the switching transistor Q7 and one end of the resistor R14. The other end of the resistor Rgl is connected to the gate of the lower bridge silicon carbide MOSFET and the anode of the diode D2. The other end of the resistor R14 is connected to the cathode of the diode D2.

9. The crosstalk suppression driving circuit for the silicon carbide MOSFET bridge circuit according to claim 1, characterized in that, The drain of the upper-bridge silicon carbide MOSFET is connected to the positive output terminal of the DC bus, the source of the upper-bridge silicon carbide MOSFET is connected to the drain of the lower-bridge silicon carbide MOSFET, and the source of the lower-bridge silicon carbide MOSFET is connected to the negative output terminal of the DC bus.

10. A power supply device, characterized in that, The crosstalk suppression drive circuit includes the silicon carbide MOSFET bridge circuit according to any one of claims 1-9.

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