IGBT driving circuit and electronic device

Abstract

The utility model discloses an IGBT drive circuit and an electronic device. The IGBT drive circuit comprises a first switch tube, a second switch tube, a voltage stabilizing circuit, a drive resistor and a blocking device. The second end of the first switching tube and the second end of the voltage stabilizing circuit are connected together and then input power supply voltage, the control end of the first switching tube and the control end of the second switching tube are connected together to input PWM signals, the first end of the first switching tube and the first end of the second switching tube are connected with one end of the driving resistor at the same time, and the other end of the driving resistor is connected with a grid electrode of a driven IGBT. The second end of the second switching tube is connected with the first end of the voltage stabilizing circuit and the first end of the blocking device at the same time, and the second end of the blocking device is used for connecting the emitter of the driven IGBT and the ground; the first switch tube is switched on when the voltage of the control end and the second end is negative voltage, and the second switch tube is switched on when the voltage of the control end and the second end is positive voltage. According to the utility model, the turn-off loss of the IGBT can be reduced, the turn-off response speed of the IGBT is improved, the circuit structure is simple, and the implementation cost is low.

Description

TECHNICAL FIELD

[0001] The utility model relates to IGBT gate drive control technology, especially a kind of IGBT drive circuit and electronic device. BACKGROUND

[0002] Insulated-gate bipolar transistor (IGBT) combines the high input impedance of MOSFET and the high current-carrying capacity of bipolar transistor (BJT);Make it important in medium and high power applications;Especially its fast switching capability and high current handling capability make it widely used in switching power supply and other power electronic systems.

[0003] At present, the IGBT using negative voltage off on the circuit is about 20% faster than traditional technology in off time, and under the same working conditions, the off loss is reduced by about 30%, which shows that the negative voltage off technology effectively improves the switching efficiency of IGBT and reduces energy loss.

[0004] Therefore, the negative voltage off performance of IGBT is one of the main indicators of IGBT, and optimizing the drive level of negative voltage is crucial to ensure the efficiency of the circuit;Too low negative voltage may not be enough to achieve fast off;And too high negative voltage may increase the stress and loss of electronic device. The commonly used gate drive circuit widely uses special drive chip with peripheral circuit scheme, but the control mode, device composition, cost, structure and performance of the existing gate drive circuit do not have advantages. UTILITY MODEL CONTENT

[0005] In view of this, the technical problem to be solved by the utility model is to provide an IGBT drive circuit and electronic device, to realize adjustable negative voltage amplitude off circuit, the utility model realizes that positive voltage drive and negative voltage off IGBT are quickly generated through the processing of digital signal drive;Less time delay in switching process;This method quickly flips gate voltage through two switching tubes, shortens the time from IGBT conduction to cutoff or vice versa. Further, it also has the characteristics of simple structure, precise control method, simple device and low cost.

[0006] As the first aspect of the utility model, the technical scheme of the embodiment of the provided IGBT drive circuit is as follows:

[0007] An IGBT driving circuit, comprising a first switch tube, a second switch tube, a voltage stabilizing circuit, a driving resistor and a direct current blocking device; the second end of the first switch tube and the second end of the voltage stabilizing circuit are connected together to input a supply voltage, the control end of the first switch tube and the control end of the second switch tube are connected together to input a PWM signal, the first end of the first switch tube and the first end of the second switch tube are connected to one end of the driving resistor, the other end of the driving resistor is used to connect the gate of a driven IGBT, the second end of the second switch tube is connected to the first end of the voltage stabilizing circuit and the first end of the direct current blocking device, and the second end of the direct current blocking device is used to connect the emitter of the driven IGBT and the ground.

[0008] The first switch tube is turned on when the voltage at its control end and second end is negative, and the second switch tube is turned on when the voltage at its control end and second end is positive; when the PWM signal is at zero level, the second switch tube is turned off under the action of the voltage stabilizing circuit, the first switch tube is turned on and generates a driving voltage for the gate of the driven IGBT, so that the driven IGBT is turned on; when the PWM signal is at high level, the first switch tube is turned off, and the second switch tube is turned on under the action of the voltage stabilizing circuit and generates a negative voltage for the gate of the driven IGBT, so that the driven IGBT is turned off.

[0009] Preferably, the first switch tube is a PMOS tube, the gate of which is the control end of the first switch tube, the drain of which is the first end of the first switch tube, and the source of which is the second end of the first switch tube.

[0010] Preferably, the second switch tube is an NMOS tube, the gate of which is the control end of the second switch tube, the drain of which is the first end of the second switch tube, and the source of which is the second end of the second switch tube.

[0011] Preferably, the voltage stabilizing circuit comprises a voltage stabilizing diode, the anode of which is the first end of the voltage stabilizing circuit, and the cathode of which is the second end of the voltage stabilizing circuit.

[0012] Further, the voltage stabilizing circuit further comprises a voltage dividing device, the anode of the voltage stabilizing diode is the first end of the voltage stabilizing circuit, the cathode of the voltage stabilizing diode and one end of the voltage dividing device are connected together to be grounded, and the other end of the voltage dividing device is the second end of the voltage stabilizing circuit.

[0013] Further, the voltage stabilizing value of the voltage stabilizing diode ZD1 is less than or equal to the supply voltage.

[0014] Preferably, the direct current blocking device is a capacitor.

[0015] Preferably, the driving resistor has an impedance less than or equal to 200Ω.

[0016] As a second aspect of the utility model, the embodiment technical scheme of the electronic device is as follows:

[0017] An electronic device, wherein the electronic device comprises an IGBT and the IGBT drive circuit of any one of the first aspect, and the IGBT drive circuit is used for driving the driven IGBT.

[0018] Further, the electronic device is a switching power supply.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] 1. The IGBT drive circuit of the embodiment of the utility model comprises a first switch tube and a second switch tube, a control end of the first switch tube and a control end of the second switch tube are connected together for inputting a PWM signal, the first switch tube is turned on when the voltage at the control end and the second end thereof is negative, and the second switch tube is turned on when the voltage at the control end and the second end thereof is positive, the self-locking control logic of the switch tube, the two switch tubes share one control signal, the number of control signals can be reduced, and therefore the turn-off loss of the IGBT can be reduced.

[0021] 2. The IGBT drive circuit of the embodiment of the utility model comprises a voltage stabilizing circuit, negative voltage can be generated by the voltage stabilizing circuit itself without additional negative voltage, and the amplitude of the negative turn-off voltage between the gate and the emitter of the IGBT when the IGBT is turned off is determined by the voltage stabilizing value of the voltage stabilizing circuit, for example, a voltage stabilizing tube with a voltage stabilizing value of 5V can generate-5V turn-off negative voltage, and therefore the amplitude of the negative turn-off voltage can be regulated according to the application condition, and the turn-off response speed of the IGBT can be improved.

[0022] 3. The IGBT drive circuit of the embodiment of the utility model only comprises a first switch tube, a second switch tube, a voltage stabilizing circuit, a driving resistor and a direct current blocking device, without additional optical coupler and analog control chip, and the circuit structure is simple and the implementation cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a specific implementation circuit application schematic diagram of the IGBT drive circuit of the first embodiment of the utility model. DETAILED DESCRIPTION

[0024] In order to make the technical scheme of the utility model clearer, the following clearly and completely describes the utility model embodiments in connection with the drawings. Obviously, the described embodiments are part of the embodiments of the utility model, and other various forms of modification, replacement or change of the utility model can be made by those skilled in the art without creative effort, and still belong to the protection scope of the utility model.

[0025] It should be noted that the terms "comprising" and "having" and any variations thereof described in the specification and claims of the present application are intended to cover non-exclusive inclusion, for example, a series of components, unit circuits or control sequences are not necessarily limited to those clearly listed, but can include components, unit circuits or control sequences that are not clearly listed or inherent to these circuits.

[0026] In addition, the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0027] It should be understood that in the specification and claims, when describing that an element is "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element; when describing that a step is connected to another step, the step can be directly connected to the other step, or connected to the other step through a third step.

[0028] First embodiment

[0029] The embodiment provides an IGBT driving circuit, Figure 1 The application principle diagram of the specific implementation circuit of the IGBT driving circuit of the first embodiment of the utility model is shown, please refer to Figure 1 The IGBT driving circuit comprises a first switch tube Q1, a second switch tube Q2, a voltage stabilizing circuit, a driving resistor R2 and a direct-current isolation device, a second end of the first switch tube Q1 and a second end of the voltage stabilizing circuit are connected together and used for inputting a power supply voltage VCC, a control end of the first switch tube Q1 and a control end of the second switch tube Q2 are connected together and used for inputting a PWM signal, a first end of the first switch tube Q1 and a first end of the second switch tube Q2 are connected to one end of the driving resistor R2 at the same time, the other end of the driving resistor R2 is used for connecting a gate of a driven IGBT Q3, a second end of the second switch tube Q2 is connected to a first end of the voltage stabilizing circuit and a first end of the direct-current isolation device at the same time, and a second end of the direct-current isolation device is used for connecting an emitter of the driven IGBT Q3 and the ground;

[0030] The first switch tube Q1 is turned on when the voltage at the control end and the second end of the first switch tube Q1 is negative voltage, and the second switch tube Q2 is turned on when the voltage at the control end and the second end of the second switch tube Q2 is positive voltage; when the PWM signal is zero level, the second switch tube Q2 is turned off under the action of the voltage stabilizing circuit, the first switch tube Q1 is turned on and generates a driving voltage for the gate of the driven IGBT Q3, so that the driven IGBT Q3 is turned on; when the PWM signal is high level, the first switch tube Q1 is turned off, and the second switch tube Q2 is turned on under the action of the voltage stabilizing circuit, and generates a negative voltage for the gate of the driven IGBT Q3, so that the driven IGBT Q3 is turned off.

[0031] Please continue to see Figure 1 , wherein:

[0032] The first switch tube Q1 is a PMOS tube, the gate of the first switch tube Q1 is the control end of the first switch tube Q1, the drain of the first switch tube Q1 is the first end of the first switch tube Q1, and the source of the first switch tube Q1 is the second end of the first switch tube Q1.

[0033] The second switch tube is an NMOS tube, the gate of the second switch tube is the control end of the second switch tube, the drain of the second switch tube is the first end of the second switch tube, and the source of the second switch tube is the second end of the second switch tube.

[0034] The voltage stabilizing circuit comprises a voltage dividing device and a voltage stabilizing diode ZD1, the anode of the voltage stabilizing diode ZD1 is the first end of the voltage stabilizing circuit, the cathode of the voltage stabilizing diode ZD1 and one end of the voltage dividing device are connected together for grounding, and the other end of the voltage dividing device is the second end of the voltage stabilizing circuit.

[0035] The voltage dividing device is a resistor R1.

[0036] The following is combined Figure 1 The working principle of the embodiment is analyzed:

[0037] The first switch tube Q1 is turned on when the voltage at the control end and the second end of the first switch tube Q1 is negative voltage, and the second switch tube Q2 is turned on when the voltage at the control end and the second end of the second switch tube Q2 is positive voltage; when the PWM signal is zero level, the second switch tube Q2 is turned off under the action of the voltage stabilizing circuit, the first switch tube Q1 is turned on and generates a driving voltage for the gate of the driven IGBT Q3, so that the driven IGBT Q3 is turned on; when the PWM signal is high level, the first switch tube Q1 is turned off, and the second switch tube Q2 is turned on under the action of the voltage stabilizing circuit, and generates a negative voltage for the gate of the driven IGBT Q3, so that the driven IGBT Q3 is turned off.

[0038] The first switch tube Q2 is turned on when the voltage at the control end and the second end of the second switch tube Q2 is positive voltage, i.e. the gate voltage VG2 is higher than the source voltage VS2, at this time the second switch tube Q2 is turned on, and the drain and source voltage VDS2 of the second switch tube Q2 is positive voltage.

[0039] VCC is the supply voltage provided by the circuit, generally greater than 12V high level; resistor R1 is a voltage divider, and the voltage divider ZD1 forms a voltage divider, which ensures that the voltage across the voltage regulator is not greater than the maximum working voltage of the breakdown voltage regulator ZD1, to avoid damaging the voltage regulator ZD1, for example, the maximum working voltage of the 5.1V voltage regulator is 15V, if VCC is 18V, it will exceed the maximum working voltage of the voltage regulator; Therefore, the resistor R1 needs to be divided, if the selection of the voltage regulator is greater than or equal to the maximum working voltage of VCC, it can also not need to set the voltage divider; The voltage regulator ZD1 is a selected voltage regulator for controlling the negative voltage off voltage amplitude, and the specific implementation generally defaults to a voltage of 3.9V or 5.1V, which is less than or equal to VCC voltage; When VCC high level works normally, the voltage regulator ZD1 breaks down, at which time the cathode level of the voltage regulator ZD1 is positive and the anode level is zero;

[0040] When the PWM signal is zero level:

[0041] The gate voltage VG2 of the NMOS tube Q2 is 0, the source voltage VS2 of the NMOS tube Q2 is the anode voltage of the voltage regulator ZD1, so VS2=0, therefore VG2=VS2, VGS2 is not positive, and the NMOS tube Q2 is cut off;

[0042] The gate voltage VG1 of the PMOS tube Q1 is 0, at this time the source voltage VS1 of the PMOS tube Q1 is VCC=high level, VS1 level is higher than VG1, VGS1 is negative, PMOS tube Q1 is forward conducting, VS1=VD1=VCC is high level, in the period of PWM zero level, generate positive pressure drive terminal module IGBT Q3 conduction, at this time the collector and emitter voltage VCE3 of IGBT Q3 is forward voltage;

[0043] When the PWM signal is high level:

[0044] The gate voltage VG1 of the PMOS tube Q1 is high level, at this time the source voltage VS1 of the PMOS tube Q1 is VCC, VGS1 is not negative, and the PMOS tube Q1 is cut off;

[0045] The gate voltage VG2 of the NMOS tube Q2 is high, at this time, the source voltage VS2 of the NMOS tube Q2 is the anode voltage of the ZD1 voltage stabilizing tube, so VS2=0, the VG2 level is higher than VS2, VGS2 is positive, the NMOS tube Q2 is forward on, since the driving resistance R2 is a resistance with small impedance (for example: less than or equal to 200Ω), at this time, the gate voltage VG3 of the terminal IGBT Q3 is forward on through the NMOS tube Q2, VG3=VD2=VS2=0, the emitter of the terminal IGBT Q3 and the cathode of the ZD1 voltage stabilizing tube are connected together, so the emitter voltage VE3 of the IGBT Q3 is the cathode voltage of the ZD1 voltage stabilizing tube, after the ZD1 voltage stabilizing tube is broken down, the cathode voltage is positive, so VE3 is positive, thus, VGE3 is negative, at this time, the IGBT Q3 is off;

[0046] Through the self-turning and self-locking logic of the above-mentioned switch tube, the IGBT can be fast forward on and fast off.

[0047] Second embodiment

[0048] The electronic device provided by the embodiment comprises an IGBT and the IGBT driving circuit of any one of the first embodiment, and the IGBT driving circuit is used for driving the IGBT.

[0049] The electronic device of the embodiment can reduce the off loss of the IGBT and improve the off response speed of the IGBT, and the circuit structure is simple and the implementation cost is low.

[0050] Further, the electronic device of the embodiment is a switching power supply.

[0051] The above is only used for describing the technical scheme of the utility model and not for limiting it, although the utility model is described in detail according to the embodiment, the ordinary skilled in the art can modify or replace the specific implementation mode of the utility model, any modification or replacement which does not depart from the spirit and scope of the utility model is within the protection scope of the claims of the utility model.

Claims

1. An IGBT driving circuit, characterized in that, The IGBT driving circuit comprises: a first switch tube, a second switch tube, a voltage stabilizing circuit, a driving resistor and a direct current blocking device; a second end of the first switch tube and a second end of the voltage stabilizing circuit are connected together to input a supply voltage, a control end of the first switch tube and a control end of the second switch tube are connected together to input a PWM signal, a first end of the first switch tube and a first end of the second switch tube are connected to one end of the driving resistor, the other end of the driving resistor is used to connect a gate of a driven IGBT, a second end of the second switch tube is connected to a first end of the voltage stabilizing circuit and a first end of the direct current blocking device, and a second end of the direct current blocking device is used to connect an emitter of the driven IGBT and the ground; when voltages at the control end and the second end of the first switch tube are negative, the first switch tube is turned on, when voltages at the control end and the second end of the second switch tube are positive, the second switch tube is turned on; when the PWM signal is at a zero level, the second switch tube is turned off under the action of the voltage stabilizing circuit, the first switch tube is turned on and generates a driving voltage for the gate of the driven IGBT, so that the driven IGBT is turned on; when the PWM signal is at a high level, the first switch tube is turned off, the second switch tube is turned on under the action of the voltage stabilizing circuit, and generates a negative voltage for the gate of the driven IGBT, so that the driven IGBT is turned off.

2. The IGBT driving circuit according to claim 1, characterized by: The first switch tube is a PMOS tube, the gate of the first switch tube is the control end of the first switch tube, the drain of the first switch tube is the first end of the first switch tube, and the source of the first switch tube is the second end of the first switch tube.

3. The IGBT driving circuit according to claim 1, characterized by: The second switch tube is an NMOS tube, the gate of the second switch tube is the control end of the second switch tube, the drain of the second switch tube is the first end of the second switch tube, and the source of the second switch tube is the second end of the second switch tube.

4. The IGBT driving circuit according to claim 1, characterized by: The voltage stabilizing circuit comprises a voltage stabilizing diode, the anode of the voltage stabilizing diode is the first end of the voltage stabilizing circuit, and the cathode of the voltage stabilizing diode is the second end of the voltage stabilizing circuit.

5. The IGBT driving circuit according to claim 4, characterized by: The voltage stabilizing circuit further comprises a voltage dividing device, the anode of the voltage stabilizing diode is the first end of the voltage stabilizing circuit, the cathode of the voltage stabilizing diode and one end of the voltage dividing device are connected together to be grounded, and the other end of the voltage dividing device is the second end of the voltage stabilizing circuit.

6. The IGBT driving circuit according to claim 4, characterized by: The voltage stabilizing value of the voltage stabilizing diode ZD1 is less than or equal to the supply voltage.

7. The IGBT driving circuit according to claim 1, characterized by: The direct current blocking device is a capacitor.

8. The IGBT driving circuit according to claim 1, characterized by: The impedance of the driving resistor is less than or equal to 200Ω.

9. An electronic device, comprising: The electronic device comprises an IGBT and the IGBT driving circuit according to any one of claims 1 to 8, and the IGBT driving circuit is used to drive the driven IGBT.

10. The electronic device of claim 9, wherein: The electronic device is a switching power supply.

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