Non-isolated MOSFET and IGBT drive circuit with negative pressure shutdown

Abstract

The present invention discloses a non-isolated MOS transistor and IGBT drive circuit with negative voltage shutdown, which includes a negative voltage pulse square wave generator and a negative voltage drive circuit. The negative voltage drive circuit includes a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a diode D1, a diode D2, a zener diode ZD1, a triode Q1 and a triode Q2, wherein: Q1 is a PNP transistor, Q2 is an NPN transistor. The positive output terminal of the negative voltage pulse square wave generator is connected to the emitter of Q1 and is also connected to the base of Q1 through R1, and the negative output terminal is grounded together with the collector of Q1; the emitter of Q1 is connected to the base of Q2 after being reversely connected to ZD1 and D1 in sequence. The collector of Q2 is connected to the drive power supply, and the emitter is connected to the gate of the controlled MOS transistor / IGBT transistor through R3. ZD1 is connected in parallel with C1, and D1 is connected in parallel with R2. D2 is also reversely connected between the base and the emitter of Q2. The effects are as follows: The circuit structure is simple, the control is convenient, it can effectively realize the safe, reliable and rapid shutdown of MOS transistors and IGBT transistors, prevent mis-triggering, and avoid tube explosion.

Description

Technical Field

[0001] The present invention relates to switch driving technology, and more particularly to a non-isolated MOS transistor and IGBT driving circuit with negative voltage shutdown. Background Art

[0002] In power electronic devices, MOS transistors or IGBT transistors are usually used as switching elements to perform high-speed switching operations. With the increase in switching speed and bus voltage, when the switching transistors in the circuit alternately perform switching operations, the drain and source of the switching transistor will bear large voltages and currents. Due to the existence of source wiring and leakage inductance factors, a large voltage change rate will act on the gate-drain capacitance of the switching transistor to generate crosstalk current, and this crosstalk current acting on the gate-source capacitance will raise or lower the gate potential; in addition, the high-speed change of the source current will also act on the common-source inductance to raise or lower the source potential. Under the action of the above two aspects, the gate-source potential will generate large positive or negative fluctuations. Excessive positive spikes are likely to exceed the threshold voltage of the switching transistor and cause mis-conduction, and excessive negative spikes may exceed the maximum negative voltage that the switching transistor can withstand, resulting in component explosion. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a non-isolated MOS transistor and IGBT driving circuit with negative voltage shutdown, mainly solving the problem that the existing MOS transistors and IGBT transistors are not completely turned off or even component explosion caused by current crosstalk during drive control.

[0004] To achieve the above object, the specific technical solutions adopted by the present invention are as follows:

[0005] A non-isolated MOS transistor and IGBT drive circuit with negative voltage shutdown, the key lies in: including a negative voltage pulse square wave generator and a negative voltage drive circuit, the negative voltage drive circuit includes resistor R1, resistor R2, resistor R3, capacitor C1, diode D1, diode D2, zener diode ZD1, triode Q1 and triode Q2, where: triode Q1 is a PNP transistor, triode Q2 is an NPN transistor, the positive output terminal of the negative voltage pulse square wave generator is connected to the emitter of triode Q1, and at the same time the positive output terminal of the negative voltage pulse square wave generator is also connected to the base of triode Q1 through resistor R1, the negative output terminal of the negative voltage pulse square wave generator and the collector of triode Q1 are grounded together; the emitter of triode Q1 is connected to the base of triode Q2 after reversely connecting zener diode ZD1 and diode D1 in sequence, the collector of triode Q2 is connected to the drive power supply, the emitter of triode Q2 is connected to the gate of the controlled MOS transistor or the gate of the controlled IGBT transistor through resistor R3, zener diode ZD1 is in parallel with capacitor C1, diode D1 is in parallel with resistor R2, and diode D2 is also reversely connected between the base and emitter of triode Q2.

[0006] Optionally, the negative voltage drive circuit further includes resistor R4, and resistor R4 is connected between the gate and source of the controlled MOS transistor or between the gate and source of the controlled IGBT transistor.

[0007] Optionally, the source of the controlled MOS transistor or the source of the controlled IGBT transistor is grounded.

[0008] Optionally, the negative voltage drive circuit further includes zener diode ZD2 and zener diode ZD3, where zener diode ZD2 and zener diode ZD3 are reversely connected in series and then in parallel with resistor R4.

[0009] Optionally, the drive power supply is a 15V DC power supply.

[0010] Optionally, the frequency of the square wave signal emitted by the negative voltage pulse square wave generator is 100KHZ, and the duty cycle is 50%.

[0011] The remarkable effect of the present invention is:

[0012] The circuit structure of the present invention is simple, the control is convenient, it can effectively realize the safe, reliable and fast shutdown of MOS transistors and IGBT transistors, prevent mis-triggering, avoid tube explosion, and is especially suitable for high-power switch fast switching application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0014] Figure 1 is the circuit schematic diagram of the specific embodiment of the present invention;

[0015] Figure 2 This is the signal simulation waveform diagram in the specific embodiment of the present invention. Specific embodiments

[0016] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0017] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and 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 thus should not be construed as limiting the present invention. In addition, in the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0018] As Figure 1 shown, this embodiment provides a non-isolated MOS tube and IGBT drive circuit with negative voltage shutdown, including a negative voltage pulse square wave generator and a negative voltage drive circuit. The output square wave signal frequency of the negative voltage pulse square wave generator is 100KHZ, and the duty cycle is 50%; the negative voltage drive circuit includes resistor R1, resistor R2, resistor R3, resistor R4, capacitor C1, diode D1, diode D2, zener diode ZD1, zener diode ZD2, zener diode ZD3, triode Q1 and triode Q2, where: triode Q1 is a PNP tube, and triode Q2 is an NPN tube;

[0019] The positive output terminal of the negative voltage pulse square wave generator is connected to the emitter of triode Q1. At the same time, the positive output terminal of the negative voltage pulse square wave generator is also connected to the base of triode Q1 through resistor R1. The negative output terminal of the negative voltage pulse square wave generator and the collector of triode Q1 are grounded together; the emitter of triode Q1 is connected to the base of triode Q2 after being reversely connected with zener diode ZD1 and diode D1 in sequence. The collector of triode Q2 is connected to the drive power supply. The drive power supply shown in the figure is a 15V DC power supply. The emitter of triode Q2 is connected to the gate of the controlled MOS tube or the gate of the controlled IGBT tube through resistor R3. Zener diode ZD1 is connected in parallel with capacitor C1, diode D1 is connected in parallel with resistor R2, and diode D2 is reversely connected between the base and emitter of triode Q2.

[0020] During specific implementation, the resistor R4 is connected between the gate and source of the controlled MOS transistor or between the gate and source of the controlled IGBT transistor. The source of the controlled MOS transistor or the source of the controlled IGBT transistor is grounded. The zener diode ZD2 and the zener diode ZD3 are reversely connected in series and then connected in parallel with the resistor R4. The zener diode ZD2, the zener diode ZD3 and the resistor R4 can form a gate protection circuit. By changing the component parameters of the zener diode ZD2 and the zener diode ZD3, the gate voltage can be adjusted, thereby effectively preventing the controlled MOS transistor or the controlled IGBT transistor from being broken down and exploding.

[0021] The working principle of the above circuit is further analyzed below:

[0022] When the output of the negative voltage pulse square wave generator is a positive pulse charge, a signal passes through the zener diode ZD1 and the resistor R2 in sequence and then drives the NPN transistor Q2 to conduct. The 15V drive power supply passes through the transistor Q2 and the resistor R3 to provide a positive pulse width drive signal for the controlled MOS transistor or the controlled IGBT transistor, controlling the turn-on of the MOS transistor or the IGBT transistor. At this time, the PNP transistor Q1 is in a non-conducting state. At the same time, another signal gradually charges the capacitor C1 under the action of the capacitor C1 and the resistor R2. After several cycles, the capacitor C1 is saturated to form a charge with positive on the left and negative on the right.

[0023] When the negative voltage pulse square wave generator outputs a 0V voltage, the signal passes through the resistor R1 to control the conduction of the PNP transistor Q1 and the turn-off of the NPN transistor Q2. At this time, the junction capacitance of the controlled MOS transistor or the controlled IGBT transistor will be connected to the source of the controlled MOS transistor or the controlled IGBT transistor in sequence through the resistor R3, the diode D2, the diode D1 and the transistor Q1, thereby quickly discharging the junction capacitance. Since the charge on the capacitor C1 cannot change suddenly, it is equivalent to discharging the junction capacitance in the reverse direction. It can be seen from the above analysis that the magnitude of the negative voltage value of the negative voltage drive can be determined by adjusting the parameters of the zener diode ZD1.

[0024] Through Figure 2 It can be seen that n_18 in the figure is the square wave waveform output by the negative voltage pulse square wave generator; n_19 is the voltage waveform at the cathode of the diode D1; gate is the drive voltage waveform of the MOS transistor, that is, the negative voltage turn-off waveform, and the waveform is relatively smooth, effectively avoiding signal crosstalk.

[0025] In summary, it can be seen that the non-isolated MOS transistor and IGBT drive circuit with negative voltage turn-off provided by the present invention can effectively reduce the current change speed of the junction capacitance, thereby effectively avoiding the phenomenon of switch mis-triggering or even explosion caused by signal crosstalk. The circuit structure is simple, the control is convenient, and it can be effectively applied to the high-power switch fast switching drive scenario.

[0026] Finally, it should be noted that the technical solutions disclosed above are only a preferred embodiment of the present invention. Of course, the scope of the rights of the present invention cannot be limited by this. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A non-isolated MOS transistor and IGBT driving circuit with negative-pressure shutdown, characterized in that: It includes a negative pressure pulse square wave generator and a negative pressure drive circuit. The negative pressure drive circuit includes resistor R1, resistor R2, resistor R3, capacitor C1, diode D1, diode D2, zener diode ZD1, triode Q1 and triode Q2, where: Triode Q1 is a PNP transistor, and triode Q2 is an NPN transistor. The positive output terminal of the negative pressure pulse square wave generator is connected to the emitter of triode Q1. At the same time, the positive output terminal of the negative pressure pulse square wave generator is also connected to the base of triode Q1 through resistor R1. The negative output terminal of the negative pressure pulse square wave generator and the collector of triode Q1 are grounded together; The emitter of triode Q1 is connected to the base of triode Q2 after being reversely connected to zener diode ZD1 and diode D1 in sequence. The collector of triode Q2 is connected to the drive power supply. The emitter of triode Q2 is connected to the gate of the controlled MOS transistor or the gate of the controlled IGBT transistor through resistor R3. The zener diode ZD1 is connected in parallel with the capacitor C1, and the diode D1 is connected in parallel with the resistor R2. The diode D2 is also reversely connected between the base and the emitter of triode Q2.

2. The non-isolated MOS transistor and IGBT drive circuit with negative pressure shutdown according to claim 1, wherein: The negative pressure drive circuit further includes resistor R4, and the resistor R4 is connected between the gate and the source of the controlled MOS transistor or between the gate and the source of the controlled IGBT transistor.

3. The non-isolated MOS transistor and IGBT drive circuit with negative-pressure shutdown according to claim 2, characterized in that: The source of the controlled MOS transistor or the source of the controlled IGBT transistor is grounded.

4. The non-isolated MOS transistor and IGBT drive circuit with negative pressure shutdown according to claim 3, characterized in that: The negative pressure drive circuit further includes zener diode ZD2 and zener diode ZD3, where zener diode ZD2 and zener diode ZD3 are connected in reverse series and then connected in parallel with the resistor R4.

5. The non-isolated MOS transistor and IGBT drive circuit with negative pressure shutdown according to any one of claims 1-4, characterized in that: The drive power supply is a 15V DC power supply.

6. The non-isolated MOS transistor and IGBT drive circuit with negative pressure shut-off according to any one of claims 1-4, characterized in that: The frequency of the square wave signal emitted by the negative pressure pulse square wave generator is 100KHZ, and the duty cycle is 50%.

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