Controllable gate current source drive circuit

Abstract

The embodiment of the present application provides a controllable gate current source driving circuit, and belongs to the technical field of electronic circuits.The driving circuit comprises a current source module for providing stable current; and a push-pull module connected with the current source module for selecting current.The controllable gate current source driving circuit provided by the present application uses an independent power supply as a bias power supply rail of the current source module, so that the output voltage of a stabilizing tube in the current source module is stable, thereby ensuring that the current source module outputs stable current from the control side, and then combining a voltage selection module capable of switching high and low voltages as a power supply rail, the output current is constant when the load voltage changes greatly, thereby improving the switching performance of the power semiconductor and reducing the power loss.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a controllable gate current source driving circuit. Background Art

[0002] In power electronics systems, power semiconductor devices play a core role, and their performance and reliability directly determine the efficiency and stability of the entire system. As voltage-controlled switching devices, the gate drive strategy of power semiconductor devices (such as MOSFETs and IGBTs) has a significant impact on their switching characteristics and power losses. Gate drivers, acting as a bridge between the controller and power semiconductor devices, shape the dynamic and static performance of power semiconductor devices by controlling the charge and discharge processes of the input capacitance and reverse transfer capacitance of power semiconductor devices. In power electronics technology, especially in renewable energy systems, higher requirements are placed on the design and optimization of gate drivers. The main requirements for designing gate drivers include reducing switching losses, controlling the current slope (di / dt) and voltage slope (dv / dt), and reducing overvoltage during shutdown and peak reverse recovery current during shutdown.

[0003] Based on their topology, traditional gate drivers are voltage-type drivers, which offer advantages such as simple structure and high robustness. Their output typically consists of an external gate resistor, a buffer, and a power supply. Traditional voltage-type gate drivers have a fixed supply voltage and preset gate resistor to set the switching characteristics of the device. However, because these values ​​are fixed, traditional voltage-type gate drivers can only effectively operate at a single operating point, making them inadequate for varying gate drive performance control requirements brought about by changing operating conditions. This presents a significant limitation for traditional voltage-type gate drivers. For example, IGBTs or MOSFETs can achieve optimal operating performance and switching characteristics under varying driving conditions (including load conditions, chip temperature, and device aging). In other words, inappropriate driving conditions or parameter settings can lead to higher switching losses, increased electromagnetic interference, device failure, and even system-level escalation, resulting in economic losses and safety hazards.

[0004] Another approach is to use a traditional current-mode gate driver, which uses a constant current source to charge the gate capacitance. Its primary advantage is that it reduces gate drive losses at higher frequencies and fast switching speeds, as well as the switching losses of power semiconductor devices. Furthermore, traditional current-mode gate drivers have high output impedance, are less susceptible to oscillation, and offer good noise immunity. However, due to their narrow compliance voltage range, they are unable to provide a constant output current if the load voltage fluctuates significantly, even exceeding the normal operating voltage range of the current source. This results in a slower gate voltage rise rate for the power semiconductor device, which in turn reduces its switching speed and increases switching losses. Summary of the Invention

[0005] This paper proposes a novel active current source gate drive circuit and method, aiming to provide a more flexible and efficient drive solution to address the challenges of fast switching and highly variable load conditions. Compared to traditional voltage- and current-mode gate drivers, this novel active current source gate drive circuit significantly improves power semiconductor switching performance and reduces power loss by dynamically adjusting drive parameters, thereby enhancing overall system reliability and efficiency. This provides an important reference for further optimizing power electronics systems.

[0006] In order to achieve the above objectives, an embodiment of the present invention provides a controllable gate current source driving circuit, comprising:

[0007] A current source module for providing a constant gate current;

[0008] The push-pull module is connected to the current source module and is used to output the gate current provided by the current source module according to the driving signal sent by the microprocessor.

[0009] Optionally, the current source module includes a first current source module and a second current source module, and the first current source module includes:

[0010] First transistor;

[0011] a first resistor, one end of the first resistor being connected to one end of the first transistor;

[0012] a second resistor, one end of the second resistor being connected to the second end of the first transistor, and the other end of the second resistor being connected to the positive electrode of the power supply;

[0013] A first voltage-stabilizing diode, wherein one end of the first voltage-stabilizing diode is connected to one end of the second resistor, the second end of the first voltage-stabilizing diode is connected to one end of the first transistor, and the third end of the first voltage-stabilizing diode is connected to the other end of the first resistor and the negative electrode of the power supply.

[0014] Optionally, the second current source module includes:

[0015] Second triode;

[0016] a third resistor, one end of the third resistor being connected to one end of the second transistor;

[0017] a fourth resistor, one end of the fourth resistor being connected to the second end of the second transistor, and the other end of the fourth resistor being connected to the positive electrode of the power supply;

[0018] A second voltage-stabilizing diode, one end of the second voltage-stabilizing diode is connected to one end of the fourth resistor, a second end of the second voltage-stabilizing diode is connected to one end of the second transistor, and a third end of the second voltage-stabilizing diode is connected to the other end of the third resistor and the negative electrode of the power supply.

[0019] Optionally, the driving circuit further includes a fifth resistor;

[0020] The push-pull module includes:

[0021] a third triode, one end of the third triode being connected to one end of the fifth resistor;

[0022] a fourth triode, wherein one end of the fourth triode is connected to one end of the third triode, a second end of the fourth triode is connected to the second end of the third triode and the gate of the power semiconductor device, and a third end of the third triode and a third end of the fourth triode are respectively connected to the other end of the first resistor and the third end of the second triode.

[0023] Optionally, the driving circuit further includes a first voltage selection module and a second voltage selection module, and the first voltage selection module includes:

[0024] First MOS tube;

[0025] a second MOS transistor, wherein one end of the second MOS transistor is connected to one end of the first MOS transistor, a second end of the second MOS transistor is connected to the second end of the first MOS transistor and the third end of the first triode, a third end of the second MOS transistor and a third end of the first MOS transistor are connected to a first positive voltage and a second positive voltage, respectively, and the first positive voltage and the second positive voltage provide different voltage values.

[0026] Optionally, the second voltage selection module includes:

[0027] The third MOS tube;

[0028] a fourth MOS transistor, wherein one end of the fourth MOS transistor is connected to one end of the third MOS transistor, a second end of the fourth MOS transistor is connected to the second end of the third MOS transistor and the other end of the third resistor, a third end of the fourth MOS transistor and a third end of the third MOS transistor are connected to a first negative voltage and a second negative voltage, respectively, and the first negative voltage and the second negative voltage provide different voltage values.

[0029] Optionally, the driving circuit further includes a detection unit, one end of which is connected to the power semiconductor device, and the detection unit is used to detect the induced voltage generated on the collector (or drain) parasitic inductance when the collector or drain current of the power semiconductor device changes.

[0030] Optionally, the driving circuit further includes:

[0031] a controller, one end of the controller being connected to the other end of the detection unit;

[0032] An isolation unit, one end of which is connected to the other end of the controller, and the other end of which is connected to one end of the first MOS transistor, the other end of the fifth resistor, and the other end of the third MOS transistor.

[0033] Optionally, the load current through the first resistor is determined using formula (1),

[0034]

[0035] Among them, I 负载 is the load current, V 参考 is the voltage on the first resistor, R1 is the resistance of the first resistor;

[0036] The resistance of the second resistor is determined by formula (2):

[0037]

[0038] Wherein, R2 is the resistance of the second resistor, V bia1 The voltage provided by the power supply connected to the second resistor, β B1 is the DC current amplification factor of the first transistor, I KA is the cathode current of the first voltage regulator tube.

[0039] Optionally, the compliance voltage range of the first current source module is determined using formula (3):

[0040] V 顺从电压范围 =V 1或2 -V CE_B1 -I 负载 R1, (3)

[0041] Among them, V 顺从电压范围 is the compliance voltage range of the first current source module, V 1或2 is the first positive voltage or the second positive voltage, V CE_B1 is the collector-emitter voltage of the first transistor when it operates in the saturation region.

[0042] Through the above technical solution, the controllable gate current source drive circuit provided by the present invention uses an independent power supply as the bias power rail of the current source module, so that the output voltage of the voltage regulator in the current source module is stable, thereby ensuring that the current source module outputs a stable current from the control side, and combined with a voltage selection module that can switch between high and low voltages as a power power rail, it achieves a constant output current when the load voltage changes significantly, thereby improving the switching performance of the power semiconductor and reducing power loss.

[0043] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0045] Figure 1 is a schematic diagram of a controllable gate current source driving circuit according to one embodiment of the present invention;

[0046] Figures 2 to 7 Schematic diagrams of various embodiments of the current source module of the controllable gate current source driving circuit according to the present invention;

[0047] Figure 8 This is a schematic diagram showing the changes in gate voltage / current and collector-emitter voltage / current during the turn-on process of an IGBT device under gate drive due to different common-emitter parasitic inductance.

[0048] Figure 9 This is a schematic diagram showing the changes in gate voltage / current and collector-emitter voltage / current during the turn-on process of an IGBT device under gate drive due to different gate parasitic inductance.

[0049] Description of Reference Numerals

[0050] 1. Controller 2. Isolation unit

[0051] 3. Power semiconductor devices 4. Detection unit

[0052] 5. First voltage selection module 6. Second voltage selection module

[0053] 7. First current source module 8. Second current source module

[0054] 9. Push-pull module B1, first transistor

[0055] B2, the second transistor B3, the third transistor

[0056] B4, fourth transistor R1, first resistor

[0057] R2, second resistor R3, third resistor

[0058] R4, fourth resistor R5, fifth resistor

[0059] M1, first MOS tube M2, second MOS tube

[0060] M3, the third MOS tube M4, the fourth MOS tube

[0061] D1, the first voltage regulator tube D1, the second voltage regulator tube DETAILED DESCRIPTION

[0062] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0063] like Figure 1 FIG. 1 is a schematic diagram of a controllable gate current source driving circuit according to an embodiment of the present invention. Figure 1 In the embodiment, the driving circuit may include a current source module and a push-pull module 9. The current source module may be used to provide a stable current, and the push-pull module 9 may be connected to the current source module to select a current. The push-pull module 9 may select different current sources according to a control signal, thereby controlling the on and off of the power semiconductor device 3.

[0064] In order to limit the current, in one embodiment of the present invention, the drive circuit may further include a fifth resistor R5 for limiting the current. Furthermore, in this embodiment, the specific form of the push-pull module 9 may be a variety known to those skilled in the art. In a preferred example of the present invention, the push-pull module 9 may include a third transistor B3 and a fourth transistor B4. One end of the third transistor B3 is connected to one end of the fifth resistor R5. One end of the fourth transistor B4 is connected to one end of the third transistor B3, the second end of the fourth transistor B4 is connected to the second end of the third transistor B3 and the gate of the power semiconductor device 3, and the third end of the third transistor and the third end of the fourth transistor B4 are respectively connected to the other end of the first resistor R1 and the third end of the second transistor B2.

[0065] In this embodiment, the form of the current source module can be various known to those skilled in the art. In a preferred example of the present invention, the current source module can include a first current source module 7 and a second current source module 8. In this embodiment, the specific form of the first current source module 7 can be various known to those skilled in the art. In a preferred example of the present invention, the first current source module 7 can include a first transistor B1, a first resistor R1, a second resistor R2 and a first voltage-stabilizing diode D1. Among them, one end of the first resistor R1 is connected to one end of the first transistor B1, one end of the second resistor R2 is connected to the second end of the first transistor B1, and the other end of the second resistor R2 is connected to the positive pole of the power supply. One end of the first voltage-stabilizing diode D1 is connected to one end of the second resistor R2, the second end of the first voltage-stabilizing diode D1 is connected to one end of the first transistor B1, and the third end of the first voltage-stabilizing diode D1 is connected to the other end of the first resistor R1 and the negative pole of the power supply. The first transistor B1 must operate exclusively in the amplification region (not the saturation region). Typically, an NPN transistor with a high β value is selected. This ensures that the collector and emitter currents are approximately equal when operating in the amplification region and improves the rigidity of the base voltage source. Specifically, due to the Early effect of the transistor, changes in the collector-emitter voltage caused by varying load voltage will cause β to change accordingly, thereby varying the base voltage through the load effect. To meet the rigidity requirements of the power supply, the output impedance of the base voltage should be much smaller than the DC impedance seen through the base, thereby stabilizing the base voltage and suppressing changes in the output current.

[0066] In this embodiment, the specific form of the second current source module 8 can be various known to those skilled in the art. In a preferred example of the present invention, the second current source module 8 may include a second triode B2, a third resistor R3, a fourth resistor R4, and a second voltage-stabilizing tube D2. Among them, one end of the third resistor R3 is connected to one end of the second triode B2, one end of the fourth resistor R4 is connected to the second end of the second triode B2, and the other end of the fourth resistor R4 is connected to the positive pole of the power supply. One end of the second voltage-stabilizing tube D2 is connected to one end of the fourth resistor R4, the second end of the second voltage-stabilizing tube D2 is connected to one end of the second triode B2, and the third end of the second voltage-stabilizing tube D2 is connected to the other end of the third resistor R3 and the negative pole of the power supply.

[0067] Various alternative implementations of the current source module can also be as follows Figures 2 to 7 shown.

[0068] To provide power rails for the first current source module 7 and the second current source module 8, in one embodiment of the present invention, the drive circuit may further include a first voltage selection module 5 and a second voltage selection module 6. In this embodiment, the specific form of the first voltage selection module 5 may be various known to those skilled in the art. In a preferred example of the present invention, the first voltage selection module 5 may further include a first MOS transistor M1 and a second MOS transistor M2. One end of the second MOS transistor M2 is connected to one end of the first MOS transistor M1, and the second end of the second MOS transistor M2 is connected to the second end of the first MOS transistor M1 and the third end of the first triode B1. The third end of the second MOS transistor M2 and the third end of the first MOS transistor M1 are respectively connected to a first positive voltage and a second positive voltage, wherein the first positive voltage provides a greater voltage value than the second positive voltage. For most SiC power MOSFET devices, the recommended first positive voltage is 40V and the second positive voltage is 20V. For most IGBT devices, the recommended first positive voltage is 40V and the second positive voltage is 15V.

[0069] In this embodiment, the specific form of the second voltage selection module 6 can be various known to those skilled in the art. In a preferred example of the present invention, the second voltage selection module 6 can further include a third MOS transistor M3 and a fourth MOS transistor M4. One end of the fourth MOS transistor M4 is connected to one end of the third MOS transistor M3, a second end of the fourth MOS transistor M4 is connected to the second end of the third MOS transistor M3 and the other end of the third resistor R3, and a third end of the fourth MOS transistor M4 and a third end of the third MOS transistor M3 are connected to a first negative voltage and a second negative voltage, respectively, where the first negative voltage provides a greater voltage value than the second negative voltage.

[0070] In order to detect changes in the collector (or drain) current of the power semiconductor device 3, in one embodiment of the present invention, the drive circuit may further include a detection unit 4. One end of the detection unit 4 is connected to the power semiconductor device 3. The detection unit 4 is used to detect the induced voltage generated on the parasitic inductance of the power circuit when the collector (or drain) current changes.

[0071] To control the charging and discharging of the power semiconductor device 3 by the first current source module 7 and the second current source module 8, in one embodiment of the present invention, the drive circuit may further include a controller 1 and an isolation unit 2. One end of the controller 1 is connected to the other end of the detection unit 4. The controller 1, as the control core, requires three output signals and one input signal. It may be composed of a CPLD, an FPGA, a single-chip microcomputer (MCU), or a combination of an FPGA and a DSP. The first function of the controller 1 is to output a high or low level signal based on system requirements or external instructions to control the on / off state of the power semiconductor device 3. The second function of the controller 1 is to receive the output signal of the detection unit 4. The third function of the controller 1 is to generate a selection signal for selecting a power rail during the on / off process based on the output signal received from the detection unit 4. One end of the isolation unit 2 is connected to the other end of the controller 1. The other end of the isolation unit 2 is also connected to one end of the first MOS transistor M1, the other end of the fifth resistor R5, and the other end of the third MOS transistor M3. The isolation unit 2 can be used for electrical isolation and to convert the logic signal emitted by the controller 1 into the voltage signal required for gate drive.

[0072] In this embodiment, the only path for the load current to flow through the first resistor R1 is through the first resistor R1. Controlling the voltage across the first resistor R1 controls the current through the load. The load current can be determined by formula (1):

[0073]

[0074] Among them, I 负载 is the load current, V 参考 is the voltage on the first resistor R1, R1 is the resistance of the first resistor R1;

[0075] In this embodiment, the base voltage of the first transistor B1 is controlled by the first voltage regulator D1. When an appropriate cathode current is provided, the first voltage regulator D1 will have sufficient open-loop gain to provide a fast response. The cathode current is determined by the second resistor R2, and the resistance of the second resistor R2 can be determined by formula (2):

[0076]

[0077] Where R2 is the resistance of the second resistor, V bia1 is the voltage provided by the power supply connected to the second resistor R2, β B1 is the DC current amplification factor of the first transistor B1, I KA is the cathode current of the first voltage regulator tube D1.

[0078] In this embodiment, the power rail voltage of the first voltage regulator D1 in the first current source module 7 is provided by an independent voltage source. Therefore, the compliance voltage range of the first current source module 7 can be determined by formula (3):

[0079] V 顺从电压范围 =V 1或2 -V CE_B1 -I 负载 R1, (3)

[0080] Among them, V 顺从电压范围 is the compliance voltage range of the first current source module 7, V 1或2 is the first positive voltage or the second positive voltage, V CE_B1 It is the collector-emitter voltage of the first transistor B1 when it operates in the saturation region.

[0081] More specifically, when the first positive voltage is applied to the first current source module 7, its compliance voltage range is calculated as follows:

[0082] V 顺从电压范围 =V1-V CE_B1 -i 负载 R1

[0083] When the second positive voltage is applied to the first current source module 7, its compliance voltage range is calculated as follows:

[0084] V 顺从电压范围 =V2-V CE_B1 -i 负载 R1

[0085] Figure 8 This is a schematic diagram showing the changes in gate voltage / current and collector-emitter voltage / current during the turn-on process of an IGBT device under gate drive due to different common-emitter parasitic inductance. Figure 9 This is a schematic diagram showing the changes in gate voltage / current and collector-emitter voltage / current during the turn-on process of an IGBT device under gate drive due to different gate parasitic inductance. Figure 8 and Figure 9 As shown, the controllable gate current source driving circuit provided by the present invention can significantly suppress the adverse effects caused by excessive changes in load voltage.

[0086] Through the above technical solution, the controllable gate current source drive circuit provided by the present invention uses an independent power supply as the bias power rail of the current source module, so that the output voltage of the voltage regulator in the current source module is stable, thereby ensuring that the current source module outputs a stable current from the control side, and combined with a voltage selection module that can switch between high and low voltages as a power power rail, it achieves a constant output current when the load voltage changes significantly, thereby improving the switching performance of the power semiconductor and reducing power loss.

[0087] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products for controlling a chip to control a controllable gate drive. Therefore, the present application can be implemented in the form of a fully hardware embodiment or an embodiment combining software and hardware aspects.

[0088] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0089] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A controllable gate current source driving circuit, characterized in that: The driving circuit includes: Current source module, used to provide stable current; A push-pull module, connected to the current source module, for selecting current; The current source module includes a first current source module and a second current source module, and the first current source module includes: First transistor; a first resistor, one end of the first resistor being connected to one end of the first transistor; a second resistor, one end of the second resistor being connected to the second end of the first transistor, and the other end of the second resistor being connected to the positive electrode of the power supply; a first voltage-stabilizing diode, wherein one end of the first voltage-stabilizing diode is connected to one end of the second resistor, a second end of the first voltage-stabilizing diode is connected to one end of the first transistor, and a third end of the first voltage-stabilizing diode is connected to the other end of the first resistor and a negative electrode of a power supply; The second current source module includes: Second triode; a third resistor, one end of the third resistor being connected to one end of the second transistor; a fourth resistor, one end of the fourth resistor being connected to the second end of the second transistor, and the other end of the fourth resistor being connected to the positive electrode of the power supply; a second voltage-stabilizing diode, wherein one end of the second voltage-stabilizing diode is connected to one end of the fourth resistor, a second end of the second voltage-stabilizing diode is connected to one end of the second transistor, and a third end of the second voltage-stabilizing diode is connected to the other end of the third resistor and the negative electrode of the power supply; The driving circuit further includes a fifth resistor; The push-pull module includes: a third triode, one end of the third triode being connected to one end of the fifth resistor; a fourth triode, wherein one end of the fourth triode is connected to one end of the third triode, a second end of the fourth triode is connected to the second end of the third triode and a gate of a power semiconductor device, and a third end of the third triode and a third end of the fourth triode are respectively connected to the other end of the first resistor and the third end of the second triode; The driving circuit further includes a first voltage selection module and a second voltage selection module. The first voltage selection module is connected to the third end of the first transistor, and the second voltage selection module is connected to the other end of the third resistor.

2. The driving circuit according to claim 1, wherein: The first voltage selection module includes: First MOS tube; a second MOS transistor, wherein one end of the second MOS transistor is connected to one end of the first MOS transistor, a second end of the second MOS transistor is connected to the second end of the first MOS transistor and the third end of the first triode, a third end of the second MOS transistor and a third end of the first MOS transistor are connected to a first positive voltage and a second positive voltage, respectively, and the first positive voltage and the second positive voltage provide different voltage values.

3. The driving circuit according to claim 2, wherein: The second voltage selection module includes: The third MOS tube; a fourth MOS transistor, wherein one end of the fourth MOS transistor is connected to one end of the third MOS transistor, a second end of the fourth MOS transistor is connected to the second end of the third MOS transistor and the other end of the third resistor, a third end of the fourth MOS transistor and a third end of the third MOS transistor are connected to a first negative voltage and a second negative voltage, respectively, and the first negative voltage and the second negative voltage provide different voltage values.

4. The driving circuit according to claim 3, wherein: The driving circuit further includes a detection unit, one end of which is connected to the power semiconductor device, and the detection unit is used to detect an induced voltage generated when the collector or drain current of the power semiconductor device changes.

5. The driving circuit according to claim 4, wherein: The driving circuit further includes: a controller, one end of the controller being connected to the other end of the detection unit; An isolation unit, one end of which is connected to the other end of the controller, and the other end of which is connected to one end of the first MOS transistor, the other end of the fifth resistor, and the other end of the third MOS transistor.

6. The driving circuit according to claim 5, wherein: The load current through the first resistor is determined using formula (1), Among them, I 负载 is the load current, V 参考 is the voltage on the first resistor, R1 is the resistance of the first resistor; The resistance of the second resistor is determined by formula (2): Wherein, R2 is the resistance of the second resistor, V bia1 The voltage provided by the power supply connected to the second resistor, β B1 is the DC current amplification factor of the first transistor, I KA is the cathode current of the first voltage regulator tube.

7. The driving circuit according to claim 5, wherein: The compliance voltage range of the first current source module is determined by formula (3): V 顺从电压范围 =V 1或2 -V CE_B1 -I 负载 R1, (3) Among them, V 顺从电压范围 is the compliance voltage range of the first current source module, V 1或2 is the first positive voltage or the second positive voltage, V CE_B1 is the collector-emitter voltage of the first transistor when it operates in the saturation region.

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