Positive and negative crosstalk suppression circuit for bridge arm of power semiconductor device

Abstract

The invention discloses a positive and negative crosstalk suppression circuit for a bridge arm of a power semiconductor device. The circuit comprises a push-pull circuit, an RCD auxiliary circuit and a semiconductor device, the push-pull circuit is connected with the RCD auxiliary circuit and then connected with the semiconductor device through the RCD auxiliary circuit; when a lower bridge arm switch tube is subjected to positive crosstalk, a passive element of an RCD auxiliary circuit generates a positive voltage at a source electrode to equivalently reduce an overvoltage applied to a gate and a source electrode of a device by the positive crosstalk, and the generated positive voltage of the source electrode can be recovered to 0V before negative crosstalk comes without influencing the negative crosstalk; during negative crosstalk, the equivalent driving resistance is reduced through the RCD auxiliary circuit, and negative overvoltage generated at the grid electrode due to Miller current is reduced. The circuit has compatibility and economical efficiency, and is simple to operate and easy to implement. The method is of great significance in improving the switching-on and switching-off reliability of the device and guaranteeing stable operation of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of power semiconductor device driving, and in particular to a positive and negative crosstalk suppression circuit for a bridge arm of a power semiconductor device, which is used for suppressing mis-conduction and reverse breakdown caused by crosstalk. Background Art

[0002] The performance of Si-based semiconductor devices has approached the limits of their physical materials. The third-generation semiconductor materials represented by silicon carbide (SiC) and gallium nitride (GaN) have gradually been widely used. With their advantages of high efficiency, high frequency and low power consumption, they are widely used in new energy power generation, aerospace, electric vehicles and other fields. However, with the increase of operating frequency, the influence of the corresponding circuit parasitic parameters will be amplified, exacerbating the crosstalk phenomenon of the semiconductor bridge arm. The conduction of the upper bridge arm will generate positive crosstalk to the semiconductor device of the lower bridge arm. When the positive crosstalk is higher than the threshold voltage of the corresponding device, the device will be mis-conducted, resulting in a bridge arm through short circuit. The shutdown of the upper bridge arm will generate negative crosstalk to the semiconductor device of the lower bridge arm. Excessive negative crosstalk will cause the device gate to break down in reverse, reducing the reliability of circuit operation. Therefore, studying how to suppress the crosstalk voltage generated by power semiconductor devices in the bridge arm circuit is of great significance to improving the working reliability of power electronic converters.

[0003] At present, the forward crosstalk suppression of power semiconductor devices is usually suppressed by adding a negative voltage source. Although the forward crosstalk is suppressed, the presence of the negative voltage source increases the impact of the negative crosstalk, making the device at risk of reverse breakdown, and increasing the design cost. The suppression of negative crosstalk generally uses a clamping circuit. This method will introduce additional devices such as MOS tubes, increase control signals and costs. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned prior art, the present invention proposes a positive and negative crosstalk suppression circuit for the bridge arm of a power semiconductor device. Through an RCD auxiliary circuit, the passive components of the RCD auxiliary circuit generate a positive voltage at the source during positive crosstalk, which can effectively suppress the positive crosstalk; at the same time, the influence of negative crosstalk will not be increased. During negative crosstalk, the equivalent driving resistance is reduced through the RCD auxiliary circuit, which can effectively suppress the negative pressure caused by the negative crosstalk and avoid device breakdown.

[0005] The technical solution adopted by the present invention is:

[0006] A power semiconductor device bridge arm positive and negative crosstalk suppression circuit, the circuit comprising:

[0007] Push-pull circuit, RCD auxiliary circuit;

[0008] The push-pull circuit is connected to an RCD auxiliary circuit, and the RCD auxiliary circuit is connected to a gate and a source of a power semiconductor device.

[0009] The push-pull circuit is used to generate a driving signal to drive the power semiconductor device;

[0010] When the power semiconductor device is subjected to positive crosstalk, the RCD auxiliary circuit generates a forward voltage at the source through the passive components of the RCD auxiliary circuit, thereby reducing the influence of the forward overvoltage during the positive crosstalk; when the power semiconductor device is subjected to negative crosstalk, the RCD auxiliary circuit reduces the equivalent driving resistance, thereby reducing the reverse overvoltage during the negative crosstalk.

[0011] The push-pull circuit comprises: MOS transistors S1 and S2; wherein the gate of the MOS transistor S1 and the gate of the MOS transistor S2 are connected to the input end of the driving signal, the drain of the MOS transistor S1 is connected to the power supply Vcc, the source of the MOS transistor S1 is connected to the source of the MOS transistor S2 and serves as the output end of the push-pull circuit; the drain of the MOS transistor S2 is connected to the ground end;

[0012] The RCD auxiliary circuit includes: resistors R1, R2, R3, R gL , capacitor C1, diodes D1, D3, D5, and voltage regulator diodes D2 and D4; one end of the resistor R1 is connected to the output end of the push-pull circuit, and the other end of the resistor R1 is connected to the cathode of the diode D1, the anode of the diode D3, and the resistor R gL one end;

[0013] The anode of the diode D1 is connected to one end of the resistor R2, and the cathode of the diode D3 is connected to the cathode of the voltage stabilizing diode D4;

[0014] Resistor R gL The other end is connected to the cathode of the diode D5 and connected together to the gate of the power semiconductor device;

[0015] The anode of the voltage zener diode D2 is respectively connected to one end of the capacitor C1 and one end of the resistor R3, and is connected to the ground terminal; the other end of the resistor R3 is connected to the anode of the diode D5;

[0016] The cathode of the Zener diode D2 is respectively connected to the other end of the capacitor C1 , the other end of the resistor R2 , and the anode of the Zener diode D4 , and are commonly connected to the source of the power semiconductor device.

[0017] The power semiconductor device is selected from different power devices, including MOSFET or GaN.

[0018] The power semiconductor device includes an equivalent capacitance C of the device gdL , C gsL , C dsL ; Capacitor C gdL One end of the capacitor C gsLOne end of each capacitor is connected to the gate of the device, and the capacitor C gdL The other end of the capacitor C dsL One end of each is connected to the drain of the device, and the capacitor C gsL The other end of the capacitor C dsL The other end is connected to the source of the device.

[0019] The present invention provides a positive and negative crosstalk suppression circuit for a power semiconductor device bridge arm, and the technical effects are as follows:

[0020] 1) Suppressing positive and negative crosstalk: This suppression circuit uses passive components to generate a positive voltage at the source, which can effectively suppress positive crosstalk without increasing negative crosstalk. By reducing the equivalent driving resistance, negative crosstalk can be effectively suppressed, ensuring the reliability of the device under high-frequency switching.

[0021] 2) High compatibility: The suppression drive circuit is suitable for a variety of power semiconductor devices, such as MOSFET, GaN, etc., and has high compatibility.

[0022] 3) High economy: Compared with the traditional active negative voltage to suppress positive crosstalk, the method of suppressing negative crosstalk by clamping circuit reduces the operation complexity and driving circuit cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of the positive and negative crosstalk suppression circuit proposed by the present invention;

[0024] Figure 2 It is a structural diagram of a half-bridge circuit of a power semiconductor device;

[0025] Figure 3 It is the switching timing diagram of the half-bridge circuit of the power semiconductor device;

[0026] FIG4(1) is a circuit schematic diagram of the circuit of the present invention working in mode T1;

[0027] FIG4(2) is a circuit schematic diagram of the circuit of the present invention working in mode T2;

[0028] FIG4(3) is a circuit schematic diagram of the circuit of the present invention working in mode T3;

[0029] FIG4 (4) is a circuit schematic diagram of the circuit of the present invention working in mode T4;

[0030] FIG4 (5) is a circuit schematic diagram of the circuit of the present invention working in mode T5;

[0031] FIG4 (6) is a circuit schematic diagram of the circuit of the present invention working in mode T6.

[0032] Figure 5 for Figure 3 Equivalent circuit diagram in mode T6.

[0033] FIG6( a ) is a double pulse waveform diagram without adding a conventional crosstalk suppression circuit;

[0034] FIG6( b ) is a forward crosstalk diagram without a conventional crosstalk suppression circuit (A in FIG6( a ));

[0035] FIG6(c) is a negative crosstalk diagram of a conventional circuit without adding a crosstalk suppression circuit (point B in FIG6(a)).

[0036] FIG. 7( a ) is a double pulse waveform diagram with the crosstalk suppression circuit of the present invention added.

[0037] FIG7( b ) is a forward crosstalk diagram (C in FIG7( a )) with the crosstalk suppression circuit of the present invention added;

[0038] FIG. 7( c ) is a negative crosstalk diagram (D in FIG. 7( a )) with the crosstalk suppression circuit of the present invention added. DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0040] like Figure 1 As shown in FIG. 1 , a power semiconductor device bridge arm positive and negative crosstalk suppression circuit of the present invention is shown. The implementation circuit of the method includes a push-pull circuit, an RCD auxiliary circuit, a power semiconductor device Q L .

[0041] The functions of each component are described as follows:

[0042] (1) Push-pull circuit: used to generate drive signals to drive power semiconductor devices;

[0043] (2) RCD auxiliary circuit: When the device is subjected to positive crosstalk, the passive components of the RCD auxiliary circuit generate a forward voltage at the source to reduce the impact of the forward overvoltage during positive crosstalk. When the device is subjected to negative crosstalk, the RCD auxiliary circuit reduces the equivalent driving resistance to reduce the reverse overvoltage during negative crosstalk.

[0044] (3) Power semiconductor devices: You can choose different power devices including MOSFET, GaN, etc.

[0045] A power semiconductor device bridge arm positive and negative crosstalk suppression circuit, such as Figure 1 As shown, the common half-bridge arm circuit is as follows Figure 2 As shown, it includes capacitor C, inductor L and bridge arm load resistor R, V DC is the bridge arm circuit power supply, where the upper bridge arm includes a driving resistor R gH , parasitic inductance L gH , L dH , LsH , parasitic capacitance C gsH , C gdH , C dsH And the driving source DC H and power semiconductor devices Q H ; The lower bridge arm includes the driving resistor R gL , parasitic inductance L gL , L dL , L sL , parasitic capacitance C gsL , C gdL , C dsL And the driving source DC L and power semiconductor devices Q L , the bridge arm Q H It is the active tube, the lower bridge arm Q L It is a passive tube. The working sequence of the half-bridge circuit is as follows: Figure 3 As shown, the working principle of this circuit is explained in combination with the timing and working mode. The specific example operation is as follows:

[0046] Mode T1 [t0-t1]: As shown in Figure 4 (1), the upper tube Q H In the off state, the lower tube Q L Diodes D1 and D5 are cut off in the reverse direction, and D3 is turned on in the forward direction, charging capacitor C1 to form a positive voltage on the right and a negative voltage on the left. The final voltage value of capacitor C1 is the voltage value V of the voltage regulator tube D2. D2 , down tube Q L The gate drive voltage is the forward voltage drop of diode D3 and the voltage regulator value V of Zener diode D4. D4 sum.

[0047] Mode T2 [t1-t2]: As shown in Figure 4 (2), this stage is the dead zone length and Q L The off time of the upper tube Q H Keep the off state, the lower tube Q L At this stage, diodes D3 and D5 are turned off in reverse direction, and diode D1 is turned on in forward direction. The forward voltage of capacitor C1 accelerates the lower tube Q L At the same time, capacitor C1 is discharged through resistors R1 and R2.

[0048] Mode T3 [t2-t3]: As shown in Figure 4(3), the lower tube Q L Keep off, the upper tube Q H Open, down pipe Q L The drain-source voltage rises rapidly, generating a Miller current that drives resistors R1 and R gL The voltage generated is positive on the right and negative on the left, which raises Q L The gate voltage of the capacitor C1 is still positive on the right and negative on the left, raising the Q LThe source voltage is equivalent to reducing the gate voltage and suppressing forward crosstalk.

[0049] Mode T4 [t3-t4]: As shown in Figure 4 (4), the lower tube Q L Keep off, the upper tube Q H Keep it open. Capacitor C1, resistors R1 and R2, and diode D1 form a loop, and C1 continues to discharge through R1 and R2.

[0050] Mode T5 [t4-t5]: As shown in Figure 4(5), the lower tube Q L Keep off, the upper tube Q H Keep it turned on. At this time, capacitor C1 is discharged to 0V.

[0051] Mode T6 [t5-t6]: As shown in Figure 4 (6), the lower tube Q L Keep off, the upper tube Q H At this time, the lower tube Q L The drain-source voltage drops rapidly, generating Miller current, diodes D1 and D5 are turned on, and D3 is turned off, which is equivalent to Figure 4 (6) Figure 5 From the circuit shown, it can be seen that the equivalent resistance of the RCD auxiliary circuit is the parallel connection of resistors R1 and R2 and the resistance R gL In series, and finally in parallel with resistor R3, as long as the resistance value of R3 is less than R gL , the equivalent resistance will be smaller than the traditional drive resistance R1 plus R gL , Miller current flows through the driving resistor, generating a negative right and positive left voltage at the gate, resulting in negative crosstalk. Since the equivalent driving resistance is smaller than the original driving resistance R1 plus R gL , reducing the reverse voltage of negative crosstalk at the gate, thereby effectively suppressing negative crosstalk.

[0052] In the above modes T1 to T6, the active tube is Figure 2 Q H , the passive tube is Figure 2 Q L .

[0053] Example:

[0054] In this embodiment, in order to verify the inhibitory effect of this circuit on positive and negative crosstalk, a double pulse test platform was built for verification and compared with the traditional non-crosstalk suppression circuit. The power semiconductor device selected in this embodiment is GaNsystem's GS61008P. Under normal conditions, the threshold voltage of the device is about 1.7V, and the maximum gate withstand voltage is -10~7V. The drain-source voltage applied in this experiment is 50V, and the load current is 30A; the parameters of the positive and negative crosstalk suppression circuit proposed in the present invention are as follows: resistor R1 is 1Ω, resistor R2 is 200Ω, resistor R3 is 2Ω, and RgL The resistor is 9Ω, the capacitor C1 is 7.5nf, the models of the Zener diodes D2 and D4 are MMSZ5229BT1G and MMSZ5232A respectively, and the models of the diodes D1, D3, and D5 are 1N5818.

[0055] The experimental results are as follows Figure 6(a) to Figure 6(c) and Figure 7(a) to Figure 7(c) As shown in Figure 6(a), the double pulse waveform of the traditional circuit without crosstalk suppression is shown in Figure 6(b) and Figure 6(c). It can be seen that the positive crosstalk of the lower tube is 3.03V and the negative crosstalk is -5.23V. The positive crosstalk has exceeded the threshold voltage of the device, 1.7V. If the dead time is too short, there will be a risk of short circuiting the upper and lower bridge arms at the same time. Although the negative crosstalk does not exceed the tolerance value, it will seriously affect the reliability of the device if it is disconnected under this condition for a long time.

[0056] FIG7(a) is a double pulse waveform using the positive and negative crosstalk suppression circuit of the present invention. FIG7(b) and FIG7(c) show that the positive crosstalk of the lower tube is reduced to -0.16V after compensation by the RCD auxiliary circuit, and the negative crosstalk is reduced to -2.52V after reducing the equivalent driving resistance by the RCD auxiliary circuit, which effectively reduces the positive and negative crosstalk and improves the device operation reliability. It also verifies the feasibility and effectiveness of the positive and negative crosstalk suppression circuit of the bridge arm of a power semiconductor device of the present invention.

[0057] The present invention discloses a positive and negative crosstalk suppression circuit for a bridge arm of a power semiconductor device, and the circuit includes a push-pull circuit, an RCD (resistance, capacitance, diode) auxiliary circuit, and a semiconductor device. The push-pull circuit is connected to the RCD auxiliary circuit, and then the semiconductor device is connected through the RCD auxiliary circuit; when the lower bridge arm switch tube is subjected to positive crosstalk, the present invention generates a positive voltage at the source through the passive components of the RCD auxiliary circuit to equivalently reduce the overvoltage added to the gate source of the device by the positive crosstalk, and the generated source positive voltage will be restored to 0V before the negative crosstalk comes, without affecting the negative crosstalk; in the case of negative crosstalk, the equivalent driving resistance is reduced through the RCD auxiliary circuit, and the negative overvoltage generated at the gate due to the Miller current is reduced. The circuit is compatible and economical, and the operation is simple and easy to implement. It is of great significance to improve the reliability of device conduction and shutdown and ensure the stable operation of the system.

Claims

1. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit, characterized in that The circuit includes: A push-pull circuit and an RCD auxiliary circuit, wherein the push-pull circuit is connected to the RCD auxiliary circuit, and the RCD auxiliary circuit is connected to a gate and a source of a power semiconductor device.

2. According to claim 1, a power semiconductor device bridge arm positive and negative crosstalk suppression circuit is characterized in that: The push-pull circuit is used to generate a driving signal to drive a power semiconductor device.

3. According to claim 2, a power semiconductor device bridge arm positive and negative crosstalk suppression circuit is characterized in that: The RCD auxiliary circuit generates a positive voltage at the source through the passive elements of the RCD auxiliary circuit when the power semiconductor device is subjected to positive crosstalk; and reduces the equivalent driving resistance through the RCD auxiliary circuit when the power semiconductor device is subjected to negative crosstalk.

4. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit according to claim 3, characterized in that: The push-pull circuit includes: MOS transistors S1 and S2; wherein the gate of the MOS transistor S1 and the gate of the MOS transistor S2 are commonly connected to the input end of the driving signal, the drain of the MOS transistor S1 is connected to the power supply Vcc, the source of the MOS transistor S1 is connected to the source of the MOS transistor S2 and serves as the output end of the push-pull circuit; the drain of the MOS transistor S2 is connected to the ground end.

5. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit according to claim 2, characterized in that: The RCD auxiliary circuit includes: resistors R1, R2, R3, R gL , capacitor C1, diodes D1, D3, D5, and voltage regulator diodes D2 and D4; one end of the resistor R1 is connected to the output end of the push-pull circuit, and the other end of the resistor R1 is connected to the cathode of the diode D1, the anode of the diode D3, and the resistor R gL one end; The anode of the diode D1 is connected to one end of the resistor R2, and the cathode of the diode D3 is connected to the cathode of the voltage stabilizing diode D4; Resistor R gL The other end is connected to the cathode of the diode D5 and connected together to the gate of the power semiconductor device; The anode of the voltage zener diode D2 is respectively connected to one end of the capacitor C1 and one end of the resistor R3, and is connected to the ground terminal; the other end of the resistor R3 is connected to the anode of the diode D5; The cathode of the Zener diode D2 is respectively connected to the other end of the capacitor C1 , the other end of the resistor R2 , and the anode of the Zener diode D4 , and are commonly connected to the source of the power semiconductor device.

6. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit according to claim 1, characterized in that: The power semiconductor device includes MOSFET or GaN.

7. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit according to claim 1, characterized in that: The power semiconductor device includes an equivalent capacitance C of the device gdL , C gsL , C dsL ; Capacitor C gdL One end of the capacitor C gsL One end of each capacitor is connected to the gate of the device, and the capacitor C gdL The other end of the capacitor C dsL One end of each is connected to the drain of the device, and the capacitor C gsL The other end of the capacitor C dsL The other end is connected to the source of the device.

8. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit according to claim 1, characterized in that: The circuit comprises: an upper bridge arm and a lower bridge arm; Among them, the upper bridge arm includes a driving resistor R gH , parasitic inductance L gH , L dH , L sH , parasitic capacitance C gsH , C gdH , C dsH And the driving source DC H and power semiconductor devices Q H ; The lower bridge arm includes a driving resistor R gL , parasitic inductance L gL , L dL , L sL , parasitic capacitance C gsL , C gdL , C dsL And the driving source DC L and power semiconductor devices Q L .

9. A power semiconductor device bridge arm positive and negative crosstalk suppression circuit according to claim 1, characterized in that: Above bridge arm Q H It is the active tube, the lower bridge arm Q L It is a passive tube, and the working process of the half-bridge circuit is as follows: Mode T1 [t0-t1]: Upper tube Q H In the off state, the lower tube Q L Turn on; diodes D1 and D5 are reverse-cut off, and D3 is forward-conducting, charging capacitor C1 to form a voltage that is positive on the right and negative on the left. The final voltage value of capacitor C1 is the voltage value V of voltage regulator tube D2. D2 , down tube Q L The gate drive voltage is the forward voltage drop of diode D3 and the voltage regulator value V of Zener diode D4. D4 sum; Mode T2 [t1-t2]: This stage is the dead zone duration and Q L The off time of the upper tube Q H Keep the off state, the lower tube Q L Turn off; in this stage, diodes D3 and D5 are turned off in reverse, and diode D1 is turned on in forward direction; the forward voltage of capacitor C1 accelerates the lower tube Q L The turn-off speed is fast; at the same time, capacitor C1 is discharged through resistors R1 and R2; Mode T3 [t2-t3]: Down tube Q L Keep off, the upper tube Q H Open, down pipe Q L The drain-source voltage rises rapidly, generating a Miller current that drives resistors R1 and R gL The voltage generated is positive on the right and negative on the left, which raises Q L The gate voltage of the capacitor C1 is positive on the right and negative on the left, raising the Q L The source voltage is equivalent to reducing the gate voltage and suppressing forward crosstalk; Mode T4 [t3-t4]: Down tube Q L Keep off, the upper tube Q H Keep it open; capacitor C1, resistors R1 and R2, and diode D1 form a loop, and C1 continues to discharge through R1 and R2; Mode T5 [t4-t5]: Down tube Q L Keep off, the upper tube Q H Keep it open; at this time, capacitor C1 discharges to 0V; Mode T6 [t5-t6]: Down tube Q L Keep off, the upper tube Q H Turn off; at this time, the lower tube Q L The drain-source voltage drops rapidly, generating Miller current, and diodes D1 and D5 are turned on, while D3 is turned off.

10. The method for suppressing positive and negative crosstalk in a bridge arm of a power semiconductor device of a suppression circuit as claimed in claim 9, characterized in that: When the lower bridge arm switch tube is subjected to positive crosstalk, the passive components of the RCD auxiliary circuit generate a positive voltage at the source to equivalently reduce the overvoltage applied to the gate and source of the device by the positive crosstalk. The generated source positive voltage will recover to 0V before the negative crosstalk comes without affecting the negative crosstalk. In the event of negative crosstalk, the equivalent driving resistance is reduced by the RCD auxiliary circuit to reduce the negative overvoltage generated at the gate due to the Miller current.

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