Miller clamp circuit, driving circuit and driving device
The Miller clamp circuit monitors and suppresses the Miller effect of silicon carbide devices in real time, solving the problem of misconduction of silicon carbide devices in high voltage, high current and high frequency environments, and improving the stability and reliability of the circuit.
Patent Information
- Application Number
- CN202422893144.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2034-11-26
AI Technical Summary
Silicon carbide devices may misbehave due to the Miller effect under high voltage, high current and high frequency working environments, affecting circuit stability and efficiency.
The Miller clamp circuit monitors the switch control terminal voltage in real time. When the absolute value is detected to be greater than or equal to the preset value, the clamp signal is quickly connected to the control terminal to suppress the Miller effect and avoid misconduction.
The switching performance of silicon carbide devices and the stability and reliability of circuits are improved, and the reliability and stability of circuits are enhanced.
Smart Images
Figure CN223437025U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of power electronics technology, and in particular relates to a Miller clamp circuit, a drive circuit, and a drive device. Background Art
[0002] In the field of power electronics, silicon carbide (SiC) devices are gradually replacing traditional silicon (Si) devices due to their superior electrical performance and high efficiency.
[0003] Silicon carbide (SiC) devices excel in high-voltage, high-current, and high-frequency operating environments, but their fast switching characteristics also introduce the Miller effect. This can cause undesirable mis-conduction of SiC devices during switching, severely impacting circuit stability and efficiency. Utility Model Content
[0004] The embodiments of the present application provide a Miller clamp circuit, a driving circuit, and a driving device, which can effectively suppress the Miller effect and avoid undesirable misconduction of silicon carbide switching devices during the switching process, thereby improving the stability and reliability of the circuit.
[0005] In a first aspect, an embodiment of the present application provides a Miller clamp circuit, comprising:
[0006] a detection module, wherein an input end thereof is electrically connected to the control end of the first switch, and the control end of the first switch is also electrically connected to the output end of the driving module, and the detection module is configured to: detect the voltage of the control end of the first switch when the output end of the driving module outputs a non-enable signal;
[0007] A Miller clamp module, wherein an input end thereof is electrically connected to an output end of the detection module, a first end thereof is electrically connected to a control end of the first switch, and a second end thereof is electrically connected to a clamp signal end. The Miller clamp module is configured to electrically connect the clamp signal end to the control end of the first switch when an absolute value of a voltage at the control end of the first switch detected by the detection module is greater than or equal to a preset absolute value of a voltage.
[0008] In a possible embodiment of the first aspect, the detection module includes:
[0009] The comparator has a first input terminal serving as the input terminal of the detection module, a second input terminal electrically connected to the preset voltage terminal, an output terminal serving as the output terminal of the detection module, and the preset voltage terminal being configured with a preset voltage.
[0010] In a possible embodiment of the first aspect, the detection module includes:
[0011] An analog-to-digital converter, an input end of the analog-to-digital converter is an input end of the detection module, and an output end of the analog-to-digital converter is an output end of the detection module;
[0012] The Miller clamp module is configured to electrically connect the clamp signal end to the control end of the first switch in a case where a digital signal corresponding to an absolute value of a voltage at the control end of the first switch detected by the analog-to-digital converter is greater than or equal to a digital signal corresponding to a preset absolute value of a voltage.
[0013] In a possible implementation of the first aspect, the Miller clamp module includes:
[0014] A Miller clamp control module, an input end of the Miller clamp control module is an input end of the Miller clamp module, and the Miller clamp control module is configured to output a first signal in a case where an absolute value of a voltage at the control end of the first switch detected by the detection module is greater than or equal to a preset absolute value of a voltage.
[0015] A switch module, a control end of the switch module is electrically connected to an output end of the Miller clamp control module, a first end of the switch module is a first end of the Miller clamp module, and a second end of the switch module is a second end of the Miller clamp module, and the switch module is configured to be turned on to electrically connect the clamp signal end to the control end of the first switch in response to the first signal output by the Miller clamp control module.
[0016] In a possible implementation of the first aspect, the switch module includes:
[0017] A switch tube, a gate of the switch tube is a control end of the switch module, a first pole of the switch tube is a first end of the switch module, and a second pole of the switch tube is a second end of the switch module.
[0018] In a possible implementation of the first aspect, the Miller clamp module is further configured to disconnect the clamp signal end from the control end of the first switch in a case where the output end of the driving module outputs an enable signal.
[0019] In a possible implementation of the first aspect, the Miller clamp module further includes:
[0020] A delay module, an input end of the delay module is electrically connected to an output end of the Miller clamp module, and an output end of the delay module is electrically connected to the control end of the first switch, and the delay module is configured to electrically connect the clamp signal end to the control end of the first switch in a case where absolute values of voltages at the control end of the first switch detected by the detection module are all greater than or equal to a preset absolute value of a voltage within a preset time period.
[0021] In a possible implementation of the first aspect, the delay module includes:
[0022] A first resistor, a first pin of the first resistor is electrically connected to the output end of the Miller clamp module, and a second pin of the first resistor is electrically connected to the control end of the first switch.
[0023] The first capacitor has a first electrode electrically connected to the control end of the first switch, and a second electrode electrically connected to the clamping signal end.
[0024] Based on the same inventive concept, in a second aspect, an embodiment of the present application further provides a driving circuit, comprising: a Miller clamp circuit and a driving module as described in any embodiment of the first aspect.
[0025] Based on the same inventive concept, in a third aspect, an embodiment of the present application further provides a driving device, comprising the driving circuit described in the second aspect.
[0026] The Miller clamp circuit, driving circuit and driving device of the embodiments of the present application. Among them, the Miller clamp circuit includes a detection module and a Miller clamp module. The input end of the detection module is electrically connected to the control end of the first switch to be detected, and the control end of the first switch is also electrically connected to the output end of the driving module. The detection module is configured to: detect the voltage of the control end of the first switch when the output end of the driving module outputs a non-enable signal. The input end of the Miller clamp module is electrically connected to the output end of the detection module, the first end of the Miller clamp module is electrically connected to the control end of the first switch, and the second end of the Miller clamp module is electrically connected to the clamp signal end. The Miller clamp module is configured to: electrically connect the clamp signal end to the control end of the first switch when the absolute value of the voltage at the control end of the first switch detected by the detection module is greater than or equal to the absolute value of the preset voltage. The Miller clamp circuit of the embodiment of the present application integrates a detection module and a Miller clamp module to monitor the voltage signal at the control end of the first switch in real time. When it is detected that the absolute value of the voltage at the control end of the first switch is greater than or equal to a preset absolute value of the voltage, that is, when the Miller effect occurs, the clamp signal end is electrically connected to the control end of the first switch. The control end of the first switch is quickly clamped by the clamp signal at the clamp signal end, which can effectively suppress the Miller effect and avoid undesirable misconduction of the first switch during the switching process, thereby improving the stability and reliability of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Other features, objects and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features and the accompanying drawings are not drawn to scale.
[0028] Figure 1 This is a schematic diagram of a circuit structure of a Miller clamp circuit provided in an embodiment of the present application;
[0029] Figure 2-A This is a circuit structure diagram of a detection module in a Miller clamp circuit provided in an embodiment of the present application;
[0030] Figure 2-Bis another circuit structure schematic diagram of a detection module in a Miller clamp circuit provided by the embodiment of the present application;
[0031] Figure 3 is a circuit structure schematic diagram of a Miller clamp module in a Miller clamp circuit provided by the embodiment of the present application;
[0032] Figure 4 is a circuit structure schematic diagram of a delay module in a Miller clamp circuit provided by the embodiment of the present application;
[0033] Figure 5 is another circuit structure schematic diagram of a Miller clamp circuit provided by the embodiment of the present application;
[0034] Figure 6 is a circuit structure schematic diagram of a driving circuit provided by the embodiment of the present application. DETAILED DESCRIPTION
[0035] The features and exemplary embodiments of various aspects of the present application will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely configured to explain the present application and are not configured to limit the present application. The present application can be implemented without some of the specific details by those skilled in the art. The following description of the embodiments is merely provided to provide a better understanding of the present application by showing examples of the present application.
[0036] It should be noted that, in this paper, relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the elements defined by the statement "include" do not exclude the presence of other identical elements in the process, method, article or device including the elements.
[0037] It should be understood that the term "and / or" used herein is merely a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.
[0038] It will be apparent to those skilled in the art that various modifications and variations can be made in this application without departing from the spirit or scope of this application. Therefore, this application is intended to cover modifications and variations of this application that fall within the scope of the corresponding claims (technical solutions claimed for protection) and their equivalents. It should be noted that the embodiments provided in the examples of this application can be combined with each other without contradiction.
[0039] Before describing the technical solutions provided by the embodiments of the present application, in order to facilitate understanding of the embodiments of the present application, the present application first specifically describes the problems existing in the related art:
[0040] In the field of power electronics, silicon carbide (SiC) devices are gradually replacing traditional silicon (Si) devices due to their superior electrical performance and high efficiency. While SiC devices excel in high-voltage, high-current, and high-frequency operating environments, their fast switching characteristics also present a significant problem: the Miller effect.
[0041] The Miller effect manifests itself as follows: Due to factors such as the manufacturing process, structural design, and operating environment of silicon carbide (SiC) devices, a tiny distributed capacitance (also known as parasitic capacitance) exists between the input (e.g., gate) and output (e.g., drain) terminals. This capacitance, known as gate-drain capacitance, feeds a portion of the output signal (the drain signal) back to the input (gate), where it is superimposed on the original input signal.
[0042] When a silicon carbide (SiC) device needs to be turned off, the Miller effect may cause an undesirable mis-turn-on phenomenon, which can seriously interfere with the normal operation of the circuit and reduce the stability and efficiency of the circuit.
[0043] Based on this, the embodiments of the present application provide a Miller clamp circuit, a driving circuit and a driving device, which can monitor the voltage signal of the control end of the first switch in real time, and when it is detected that the absolute value of the voltage at the control end of the first switch is greater than or equal to the absolute value of the preset voltage, that is, when the Miller effect occurs, the clamp signal end is electrically connected to the control end of the first switch, so that the control end of the first switch is quickly clamped by the clamp signal of the clamp signal end, which can effectively suppress the Miller effect and avoid the first switch from generating undesirable misconduction during the switching process, thereby improving the stability and reliability of the circuit.
[0044] The Miller clamp circuit provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.
[0045] Figure 1 is a circuit structure diagram of a Miller clamp circuit provided in an embodiment of the present application, such as Figure 1 As shown, the Miller clamp circuit 100 may include a detection module 10 and a Miller clamp module 20 .
[0046] The input end of the detection module 10 is electrically connected to the control end of the first switch 200 , and the control end of the first switch 200 is also electrically connected to the output end of the driving module 300 .
[0047] The detection module 10 is configured to detect the voltage of the control terminal of the first switch 200 when the output terminal of the driving module 300 outputs a non-enabling signal.
[0048] The first switch 200 is a switch device with Miller effect, such as an existing silicon carbide (SiC) device or other higher performance power electronic devices. The first switch 200 can be an N-type transistor or a P-type transistor.
[0049] The disabling signal outputted from the output terminal of the driving module 300 is used to control the first switch 200 to be disconnected.
[0050] Specifically, the signal output by the driver module 300 can control the on / off state of the first switch 200. For example, the first switch 200 can be turned on in response to an enable signal output by the driver module 300, and can also be turned off in response to a disable signal output by the driver module 300. When the driver module 300 outputs a disable signal, the ideal state of the first switch 200 is the off state. However, due to the Miller effect, the first switch 200 may be mis-conducted. In this case, the voltage at the control terminal of the first switch 200 is monitored in real time by the detection module 10, which can be used to subsequently determine whether to clamp the control terminal of the first switch 200 to prevent mis-conduction of the first switch 200.
[0051] The input end of the Miller clamp module 20 is electrically connected to the output end of the detection module 10 , the first end of the Miller clamp module 20 is electrically connected to the control end of the first switch 200 , and the second end of the Miller clamp module 20 is electrically connected to the clamp signal end.
[0052] The Miller clamp module 20 is configured to electrically connect the clamp signal terminal to the control terminal of the first switch 200 when the absolute value of the voltage at the control terminal of the first switch 200 detected by the detection module 10 is greater than or equal to a preset absolute value of the voltage.
[0053] The clamp signal terminal may be configured with a clamp signal, and the clamp signal is used to control the first switch 200 to be disconnected.
[0054] Specifically, when the absolute value of the voltage at the control terminal of first switch 200 detected by detection module 10 reaches or exceeds a preset absolute value, indicating the Miller effect, the Miller clamp module 20 electrically connects the clamp signal terminal to the control terminal of first switch 200, transmitting the clamp signal at the clamp signal terminal to the control terminal of first switch 200, thereby controlling the first switch to remain in the off state. Active Miller clamping technology precisely controls the voltage at the control terminal of first switch 200 during its switching process, preventing false turn-on, thereby improving the efficiency and stability of the entire circuit.
[0055] It should be noted that "the output terminal of the driver module 300 outputs a disable signal" indicates that the first switch 200 needs to be turned off. "The absolute value of the voltage at the control terminal of the first switch is greater than or equal to the absolute value of the preset voltage" indicates that the control terminal of the first switch 200 has reached the turn-on voltage. Therefore, if the output terminal of the driver module 300 outputs a disable signal, and the detection module 10 detects that the absolute value of the voltage at the control terminal of the first switch is greater than or equal to the absolute value of the preset voltage, this indicates that the first switch 200 has been mis-turned on when it should have been turned off.
[0056] According to an embodiment of the present application, a Miller clamp circuit 100 includes a detection module 10 and a Miller clamp module 20. The input terminal of the detection module 10 is electrically connected to the control terminal of the first switch 200 being detected, which is also electrically connected to the output terminal of the driver module 300. The detection module 10 is configured to detect the voltage at the control terminal of the first switch 200 when the output terminal of the driver module 300 outputs a disable signal. The input terminal of the Miller clamp module 20 is electrically connected to the output terminal of the detection module 10, the first terminal of the Miller clamp module 20 is electrically connected to the control terminal of the first switch 200, and the second terminal of the Miller clamp module 20 is electrically connected to the clamp signal terminal. The Miller clamp module 20 is configured to electrically connect the clamp signal terminal to the control terminal of the first switch 200 when the absolute value of the voltage at the control terminal of the first switch 200 detected by the detection module 10 is greater than or equal to a preset voltage absolute value. The Miller clamp circuit 100 of the embodiment of the present application integrates a detection module 10 and a Miller clamp module 20 to monitor the voltage signal at the control terminal of the first switch 200 in real time. Upon detecting that the absolute value of the voltage at the control terminal of the first switch 200 is greater than or equal to a preset absolute value of the voltage, i.e., upon the occurrence of the Miller effect, the clamp signal terminal is electrically connected to the control terminal of the first switch 200. Thus, the control terminal of the first switch 200 is rapidly clamped via the clamp signal at the clamp signal terminal. This effectively suppresses the Miller effect through real-time monitoring and active control, preventing undesirable mis-conduction of the first switch 200 during the switching process, thereby improving the switching performance and reliability of the SiC device and the stability and reliability of the circuit.
[0057] The following combination Figure 2-A and Figure 2-B The specific structure of the detection module 10 in the Miller clamp circuit 100 provided in an embodiment of the present application is introduced.
[0058] Figure 2-A Schematic diagram of a circuit structure of the detection module 10 in the Miller clamp circuit 100 provided in an embodiment of the present application.
[0059] In some embodiments, as Figure 2-A As shown, the detection module 10 may include a comparator 11 .
[0060] The first input terminal of the comparator 11 serves as the input terminal of the detection module 10 , the second input terminal of the comparator 11 is electrically connected to the preset voltage terminal, the output terminal of the comparator 11 serves as the output terminal of the detection module 10 , and the preset voltage terminal is configured with a preset voltage.
[0061] The preset voltage terminal can be configured with a preset voltage, which can be set based on the turn-on voltage of the first switch 200. For example, if the first switch 200 is an N-type transistor and its turn-on voltage is +2V, the preset voltage configured at the preset voltage terminal is a positive voltage and can be slightly lower than or equal to the turn-on voltage (e.g., +1.9V or +2V, etc.) to provide a certain safety margin. If the voltage at the control terminal of the first switch 200 detected by the detection module 10 is greater than or equal to the preset voltage, the clamp signal terminal is electrically connected to the control terminal of the first switch 200. For another example, if the first switch 200 is a P-type transistor and its turn-on voltage is -2V, the preset voltage configured at the preset voltage terminal is a negative voltage and can be slightly higher than or equal to the turn-on voltage (e.g., -1.9V or -2V, etc.). If the absolute value of the voltage at the control terminal of the first switch 200 detected by the detection module 10 is greater than or equal to the absolute value of the preset voltage, the clamp signal terminal is electrically connected to the control terminal of the first switch 200.
[0062] Specifically, the detection module 10 can implement its function through a comparator 11, wherein the first input terminal of the comparator 11 receives the signal to be detected (the voltage at the control terminal of the first switch 200), the second input terminal is connected to the preset voltage terminal, and the output terminal of the comparator 11 is used as the output of the detection result, which is used to indicate the comparison result of the signal to be detected (the voltage at the control terminal of the first switch 200) and the preset voltage. For example, when the comparator 11 outputs a low level, it means that the voltage at the control terminal of the first switch 200 is less than the preset voltage of the preset voltage terminal, and the Miller effect does not occur. For another example, when the comparator 11 outputs a high level, it means that the voltage at the control terminal of the first switch 200 is greater than or equal to the preset voltage of the preset voltage terminal, and the Miller effect occurs.
[0063] In the embodiment of the present application, the detection module 10 can implement its functions through the comparator 11. The comparator 11 can accurately determine whether the Miller effect occurs by comparing the voltage at the control terminal of the first switch 200 with the preset voltage at the preset voltage terminal, and output the detection result to the Miller clamping module 20. When the detection result of the detection module 10 is that the absolute value of the voltage at the control terminal of the first switch 200 is greater than or equal to the absolute value of the preset voltage, the Miller clamping module 20 can quickly electrically connect the clamping signal terminal to the control terminal of the first switch 200. This can effectively avoid misconduction of the first switch 200, avoid circuit instability caused by the Miller effect, and improve the reliability and stability of the circuit.
[0064] Figure 2-B Schematic diagram of another circuit structure of the detection module 10 in the Miller clamp circuit 100 provided in an embodiment of the present application.
[0065] In some embodiments, as Figure 2-B As shown, the detection module 10 may include an analog-to-digital converter 12 .
[0066] The input end of the analog-to-digital converter 12 serves as the input end of the detection module 10 , and the output end of the analog-to-digital converter 12 serves as the output end of the detection module 10 .
[0067] Specifically, the analog-to-digital converter 12 may convert the detected analog signal (the voltage at the control terminal of the first switch 200 ) into a corresponding digital signal and transmit the digital signal to the Miller clamp module.
[0068] The Miller clamp module 20 is configured to electrically connect the clamp signal terminal to the control terminal of the first switch 200 when the digital signal corresponding to the absolute value of the voltage at the control terminal of the first switch 200 detected by the analog-to-digital converter 12 is greater than or equal to the digital signal corresponding to the preset absolute value of the voltage.
[0069] In the embodiment of the present application, the detection module 10 can implement its function through the analog-to-digital converter 12 to accurately convert the analog voltage signal at the first switch control terminal in the Miller clamp circuit into a digital signal, which facilitates the subsequent Miller clamp module 20 to compare with the digital signal corresponding to the preset voltage, thereby accurately determining whether the clamping function needs to be activated, thereby improving the accuracy and response speed of circuit control.
[0070] The following combination Figure 3 The specific structure of the Miller clamp module 20 in the Miller clamp circuit 100 provided in an embodiment of the present application is introduced.
[0071] Figure 3 Schematic diagram of a circuit structure of the Miller clamp module 20 in the Miller clamp circuit 100 provided in an embodiment of the present application.
[0072] In some embodiments, as Figure 3 As shown, the Miller clamp module 20 may include a Miller clamp control module 21 and a switch module 22 .
[0073] An input end of the Miller clamp control module 21 serves as an input end of the Miller clamp module 20 .
[0074] The Miller clamp control module 21 is configured to output a first signal when the absolute value of the voltage at the control terminal of the first switch 200 detected by the detection module 10 is greater than or equal to a preset absolute value of the voltage.
[0075] The first signal is a valid signal for controlling the switch module 22 to be turned on.
[0076] The control end of the switch module 22 is electrically connected to the output end of the Miller clamp control module 21 . The first end of the switch module 22 serves as the first end of the Miller clamp module 20 , and the second end of the switch module 22 serves as the second end of the Miller clamp module 20 .
[0077] The switch module 22 is configured to be turned on in response to the first signal output by the Miller clamp control module 21 , so as to electrically connect the clamp signal terminal to the control terminal of the first switch 200 .
[0078] In an embodiment of the present application, the Miller clamp module 20 may include a Miller clamp control module 21 and a switch module 22. The Miller clamp control module 21 may output a first signal when the detection module 10 detects that the absolute value of the voltage at the control end of the first switch 200 is greater than or equal to the absolute value of the preset voltage. The switch module is then turned on in response to the first signal to electrically connect the clamp signal end to the control end of the first switch 200, thereby quickly clamping the control end of the first switch 200 through the clamp signal at the clamp signal end, effectively suppressing the Miller effect and avoiding undesirable misconduction of the first switch 200 during the switching process, thereby improving the stability and reliability of the circuit.
[0079] In some embodiments, you can continue to see Figure 3 The switch module 22 includes a switch tube T1.
[0080] The gate of the switch tube T1 serves as the control end of the switch module 22 , the first electrode of the switch tube T1 serves as the first end of the switch module 22 , and the second electrode of the switch tube T1 serves as the second end of the switch module 22 .
[0081] The switch tube T1 may be a MOSFET, or a triode or TFT type switch.
[0082] The switch module 22 of the embodiment of the present application can realize its function through the switch tube T1. The gate, first pole and second pole of the switch tube T1 serve as the control end, first end and second end of the switch module 22 respectively, which simplifies the circuit structure, improves the operating efficiency and response speed of the Miller clamp module 20, and ensures the accurate transmission of the clamping signal.
[0083] In some embodiments, the Miller clamp module 20 is further configured to disconnect the clamp signal terminal from the control terminal of the first switch 200 when the output terminal of the driving module 300 outputs an enable signal.
[0084] In the embodiment of the present application, the Miller clamp module 20 can automatically disconnect the clamp signal terminal from the control terminal of the first switch 200 when the driver module 300 outputs an enable signal, so that the first switch 200 can be normally turned on in response to the enable signal output by the driver module 300, ensuring that the circuit can operate stably and reliably.
[0085] The following combination Figure 4 The specific structure of the delay module 30 in the Miller clamp circuit 100 provided in an embodiment of the present application is introduced.
[0086] Figure 4 Schematic diagram of a circuit structure of the delay module 30 in the Miller clamp circuit 100 provided in an embodiment of the present application.
[0087] In some embodiments, as Figure 4 As shown, the Miller clamp circuit 100 may further include a delay module 30 .
[0088] An input end of the delay module 30 is electrically connected to an output end of the Miller clamp module 20 , and an output end of the delay module 30 is electrically connected to a control end of the first switch 200 .
[0089] The delay module 30 is configured to electrically connect the clamp signal terminal to the control terminal of the first switch 200 when the absolute value of the voltage at the control terminal of the first switch 200 detected by the detection module 10 within a preset period of time is greater than or equal to a preset absolute value of the voltage.
[0090] The Miller clamp circuit 100 provided in the embodiment of the present application may further include a delay module 30. When the delay module 30 detects that the absolute value of the voltage at the control terminal of the first switch continuously satisfies a preset condition (the absolute value of the voltage at the control terminal of the first switch 200 is greater than or equal to the absolute value of the preset voltage), it can introduce a delay module 30 with a time delay function and then connect the clamping signal to the control terminal of the first switch, thereby helping to avoid false triggering of the first switch 200, thereby improving the reliability and stability of the circuit.
[0091] In some embodiments, you can continue to see Figure 4The delay module 30 may include a first resistor 31 and a first capacitor 32 .
[0092] A first pin of the first resistor 31 is electrically connected to the output end of the Miller clamp module 20 , and a second pin of the first resistor 31 is electrically connected to the control end of the first switch 200 .
[0093] A first electrode of the first capacitor 32 is electrically connected to the control terminal of the first switch 200 , and a second electrode of the first capacitor 32 is electrically connected to the clamp signal terminal.
[0094] Among them, the delay module 30 has a time delay function. By utilizing the physical property that the charging process of the first capacitor 32 requires a certain amount of time, and the current limiting effect of the first resistor 31, when the absolute value of the voltage at the control end of the first switch 200 detected by the detection module 10 is greater than or equal to the absolute value of the preset voltage for a period of time (preset period), the first capacitor 32 is gradually charged to a certain voltage level through the first resistor 31. This charging process generates a time delay, thereby causing the output signal to have a certain lag relative to the input signal. Among them, the preset period can be determined by setting the resistance value of the first resistor 31 and the capacitance value of the first capacitor 32.
[0095] The embodiment of the present application adopts a delay module 30 including a first resistor 31 and a first capacitor 32. By utilizing the physical properties of the capacitor charging time and the resistor current limiting, delayed processing of the input signal is achieved, ensuring that the clamping signal is transmitted to the first switch control terminal with a lag only after it is detected that the voltage at the first switch control terminal meets the conditions for a period of time. This effectively avoids false triggering, improves the switching performance and reliability of the SiC device, and enhances the reliability and stability of the circuit.
[0096] In one example, after the switch module 22 electrically connects the clamp signal terminal to the control terminal of the first switch 200, the detection module 10 can continuously monitor the voltage at the control terminal of the clamped first switch 200. If the clamp voltage returns to a normal range (the absolute value of the voltage at the control terminal of the first switch 200 is less than a preset absolute value), the Miller clamp control module 21 can control the switch module 22 to stop the clamping operation, turning off the MOSFET switch and resuming normal operation. This means disconnecting the clamp signal terminal from the control terminal of the first switch 200. This entire process is implemented through high-speed feedback, ensuring the accuracy and timeliness of the clamping operation.
[0097] Figure 5 This is another circuit structure diagram of the Miller clamp circuit 100 provided in an embodiment of the present application.
[0098] In one example, if Figure 5 As shown, the working stages of the Miller clamp circuit 100 mainly include:
[0099] 1) Detection stage: The detection module 10 monitors the control terminal voltage of the first switch 200 in real time, and when the voltage change exceeds the preset voltage of the preset voltage terminal, it is fed back to the Miller clamp module 20.
[0100] The detection module 10 includes a comparator 11. The inverting input of the comparator 11 is electrically connected to the gate of the N-type transistor in the first switch, and the non-inverting input of the comparator 11 is electrically connected to the preset voltage terminal. The comparator 11 can be implemented using a high-speed operational amplifier (e.g., an OPA series operational amplifier) and can monitor the control terminal voltage of the first switch 200 in real time. When the control terminal voltage of the first switch 200 changes beyond a set threshold (preset voltage), the comparator 11 outputs a signal indicating that a possible Miller effect has been detected.
[0101] It should be noted that the first switch 200 can be an N-type transistor or a P-type transistor. In the case where the first switch 200 is an N-type transistor, the turn-on voltage of the first switch 200 is a positive voltage, the control terminal of the first switch 200 is electrically connected to the inverting input terminal of the comparator 11, and the non-inverting input terminal of the comparator 11 is electrically connected to the preset voltage terminal, which is configured with a positive voltage and is slightly lower than or equal to the turn-on voltage of the first switch 200. Figure 5 When the first switch 200 is a P-type transistor, the turn-on voltage of the first switch 200 is a negative voltage. The control terminal of the first switch 200 is electrically connected to the non-inverting input terminal of the comparator 11, and the inverting input terminal of the comparator 11 is electrically connected to the preset voltage terminal. The preset voltage terminal is configured with a negative voltage and is slightly higher than or equal to the turn-on voltage of the first switch 200.
[0102] 2) Control stage: The Miller clamp control module 21 decides whether to start the switch module 22 with the clamping function according to the feedback from the detection module 10 .
[0103] The Miller clamp control module 21 can utilize a logic circuit or a microcontroller (MCU) to process the output signal of the detection module 10. The Miller clamp control module 21 can analyze the input signal to determine whether the clamp circuit needs to be activated. For example, if the detection module 10 detects that the voltage at the control terminal of the first switch 200 is greater than or equal to a preset voltage, the Miller clamp control module 21 will analyze whether the first switch 200 needs to be in the off state. If the voltage at the control terminal of the first switch 200 is greater than or equal to the preset voltage and the first switch 200 needs to be off, the Miller clamp control module 21 will activate the switch module 22 with the clamping function.
[0104] For example, the driving module 300 may output a flag signal to the Miller clamp control module 21 , and the Miller clamp control module 21 may analyze whether the first switch 200 is in a state that needs to be disconnected based on the flag signal.
[0105] 3) Clamping stage: When the output terminal of the driving module 300 outputs a non-enable signal and the voltage at the control terminal of the first switch 200 exceeds the preset voltage of the preset voltage terminal, the switch module 22 automatically clamps the voltage at the control terminal of the first switch 200 to suppress changes in the voltage at the control terminal of the first switch 200 and prevent the first switch 200 from being mis-conducted. The automation of the clamping operation is achieved through the logic control circuit, reducing manual intervention, and has low power consumption and fast response, ensuring that the clamping operation does not affect the efficiency of the entire circuit.
[0106] The switch module 22 can be a high-speed MOSFET switch connected between the control terminal and the clamp signal terminal of the first switch 200. When the Miller clamp control module 21 decides to initiate clamping, the MOSFET quickly turns on, clamping the voltage at the control terminal of the first switch 200 to a safe level (for example, the clamp signal VSS at the clamp signal terminal is 0V), thereby preventing the first switch 200 from being mis-turned on.
[0107] The detection module 10 continuously monitors the voltage at the control terminal of the clamped first switch 200. If the clamped voltage returns to a normal range, the Miller clamp control module 21 controls the switch module 22 to stop the clamping operation, turning off the MOSFET and resuming normal operation. This entire process is implemented through high-speed feedback, ensuring the accuracy and timeliness of the clamping operation.
[0108] It should be noted that the embodiments of the present application are not only applicable to SiC devices, but can also be extended and applied to higher performance power electronic devices.
[0109] It should also be noted that the embodiment of the present application can flexibly set the preset voltage value of the preset voltage terminal and the delay time of the delay module 30, so as to optimize the control logic to cope with different working conditions and adapt to SiC devices of different types and specifications.
[0110] The Miller clamp circuit 100 provided in this application achieves rapid response and effective clamping to voltage changes of SiC devices through real-time monitoring and active control, thereby improving circuit efficiency, reliability and stability. At the same time, the circuit design is simple, easy to implement, and highly adaptable, without increasing system complexity, and has broad application prospects.
[0111] Figure 6 1 is a schematic diagram of a circuit structure of a driving circuit 1000 provided in an embodiment of the present application.
[0112] Based on the same inventive concept, Figure 6As shown, an embodiment of the present application further provides a driving circuit 1000 , which may include the Miller clamp circuit 100 and the driving module 300 as described in any of the above embodiments.
[0113] Based on the same inventive concept, in a third aspect, an embodiment of the present application further provides a driving device, comprising the driving circuit 1000 described in any of the above embodiments.
[0114] The driving device includes the driving circuit 1000 provided in any one of the above embodiments, and the driving circuit 1000 includes the Miller clamp circuit 100 provided in any one of the above embodiments. Therefore, the driving device and the driving circuit 1000 have all the beneficial effects of the Miller clamp circuit 100.
[0115] It should be understood that in the embodiments of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.
[0116] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.
Claims
1. A Miller clamp circuit, characterized in that: include: a detection module, wherein an input end thereof is electrically connected to the control end of the first switch, and the control end of the first switch is also electrically connected to the output end of the driving module, and the detection module is configured to: detect the voltage of the control end of the first switch when the output end of the driving module outputs a non-enable signal; A Miller clamp module, wherein an input end thereof is electrically connected to the output end of the detection module, a first end thereof is electrically connected to the control end of the first switch, and a second end thereof is electrically connected to the clamp signal end. The Miller clamp module is configured to electrically connect the clamp signal end to the control end of the first switch when an absolute value of a voltage at the control end of the first switch detected by the detection module is greater than or equal to a preset absolute value of a voltage.
2. The Miller clamp circuit according to claim 1, wherein: The detection module includes: A comparator, wherein a first input terminal thereof serves as an input terminal of the detection module, a second input terminal thereof is electrically connected to a preset voltage terminal, an output terminal thereof serves as an output terminal of the detection module, and the preset voltage terminal is configured with a preset voltage.
3. The Miller clamp circuit according to claim 1, wherein: The detection module includes: an analog-to-digital converter, whose input end serves as the input end of the detection module and whose output end serves as the output end of the detection module; The Miller clamp module is configured to electrically connect the clamp signal terminal to the control terminal of the first switch when the digital signal corresponding to the absolute value of the voltage at the control terminal of the first switch detected by the analog-to-digital converter is greater than or equal to the digital signal corresponding to the absolute value of a preset voltage.
4. The Miller clamp circuit according to claim 1, wherein: The Miller clamp module includes: a Miller clamp control module, whose input terminal serves as the input terminal of the Miller clamp module, and the Miller clamp control module is configured to: output a first signal when the absolute value of the voltage at the first switch control terminal detected by the detection module is greater than or equal to a preset absolute value of the voltage; A switch module, whose control end is electrically connected to the output end of the Miller clamp control module, whose first end serves as the first end of the Miller clamp module, and whose second end serves as the second end of the Miller clamp module. The switch module is configured to: be turned on in response to the first signal output by the Miller clamp control module to electrically connect the clamp signal end to the control end of the first switch.
5. The Miller clamp circuit according to claim 4, wherein: The switch module includes: The switching tube has a gate serving as the control end of the switching module, a first electrode serving as the first end of the switching module, and a second electrode serving as the second end of the switching module.
6. The Miller clamp circuit according to claim 1, wherein: The Miller clamp module is further configured to disconnect the clamp signal terminal from the control terminal of the first switch when the output terminal of the driving module outputs an enable signal.
7. The Miller clamp circuit according to claim 1, wherein: Also includes: a delay module, whose input end is electrically connected to the output end of the Miller clamp module, and whose output end is electrically connected to the control end of the first switch, wherein the delay module is configured to electrically connect the clamp signal end to the control end of the first switch when the absolute value of the voltage at the control end of the first switch detected by the detection module within a preset time period is greater than or equal to a preset absolute value of the voltage.
8. The Miller clamp circuit according to claim 7, wherein: The delay module includes: a first resistor, a first pin of which is electrically connected to the output end of the Miller clamp module, and a second pin of which is electrically connected to the control end of the first switch; A first capacitor has a first electrode electrically connected to the control end of the first switch, and a second electrode electrically connected to the clamping signal end.
9. A driving circuit, characterized in that: include: The Miller clamp circuit and driver module according to any one of claims 1 to 8.
10. A driving device, characterized in that: comprising the driving circuit as claimed in claim 9.