Crosstalk suppression driving circuit

Abstract

The invention belongs to the field of power device driving, particularly relates to the technical field of crosstalk suppression, and more particularly relates to a crosstalk suppression driving circuit. Through cooperative work of the driving module, the detection module, the buffering module and the clamping module, crosstalk is effectively suppressed while the switching speed is ensured. The driving module ensures normal switching action of the power device; the detection module converts the drain voltage change rate into a detection signal in real time, and recognizes the crosstalk risk in advance; the buffer module suppresses forward crosstalk by absorbing grid forward voltage spikes; the clamping module immediately conducts a low-impedance path from the grid electrode to the negative power supply when the detection signal exceeds a threshold value, and negative crosstalk is quickly eliminated. According to the design, the suppression circuit is only activated when the voltage change rate exceeds the standard, switching delay caused by a traditional fixed buffer circuit is avoided, accurate and rapid crosstalk suppression can be achieved, and finally the suppression effect and the system reliability are remarkably improved while the high-speed switching performance is maintained.

Description

Technical Field

[0001] This application belongs to the field of power device driving, specifically relating to the field of crosstalk suppression technology; more specifically, it relates to a crosstalk suppression driving circuit. Background Technology

[0002] Third-generation wide-bandgap semiconductor power devices, represented by silicon carbide and gallium nitride, have become core components for realizing high-frequency, high-efficiency, and high-power-density power electronic converters due to their superior characteristics such as high switching speed, low on-resistance, high operating junction temperature, and high thermal conductivity. However, the extremely high switching speed also brings severe challenges, among which gate crosstalk is particularly prominent.

[0003] Specifically, in bridge circuits such as half-bridge and full-bridge, when the switching transistor (active transistor) of one bridge arm switches at high speed, its rapidly changing drain-source voltage is coupled to its gate through the Miller capacitance of the complementary transistor (passive transistor), generating a coupling current. This current flows through the gate resistance of the passive transistor, generating an additional gate-source voltage. When the active transistor is turned off, a negative voltage spike, i.e., negative crosstalk, will be generated at the gate of the passive transistor, which may exceed the device's maximum negative gate withstand voltage, leading to gate oxide breakdown. When the active transistor is turned on, a positive voltage spike, i.e., positive crosstalk, may be generated. If this exceeds the device's threshold voltage, it may cause the passive transistor to mis-turn on, resulting in bridge arm shoot-through and device burnout.

[0004] To suppress crosstalk, existing technologies can be divided into passive and active methods. Passive methods, such as optimizing PCB layout, are simple and reliable, but often come at the cost of sacrificing switching speed, increasing losses, and increasing size. Active methods, such as active Miller clamping, can dynamically adjust drive parameters, but they suffer from problems such as circuit complexity, poor versatility, reliance on precise parameter extraction, response delay, or susceptibility to parasitic parameter interference.

[0005] Therefore, there is an urgent need for a drive circuit solution that can respond quickly, effectively suppress turn-off crosstalk and voltage spikes, and is easy to implement without affecting switching performance, in order to manufacture highly reliable, energy-saving and environmentally friendly integrated drive circuits or modules and promote the development of the green and smart grid industry. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this application is to provide a crosstalk suppression driving circuit, which aims to solve the problem that the current power device crosstalk suppression driving cannot take into account both switching performance and suppression effect, resulting in poor crosstalk suppression performance.

[0007] The first aspect of this application relates to a crosstalk suppression driving circuit, comprising: a driving module, a detection module, a buffer module, and a clamping module; a first terminal of the driving module is connected to the gate of a power device; a first terminal of the detection module is connected to the drain of the power device, a second terminal of the detection module is connected to a negative power supply, and a third terminal of the detection module is connected to the first terminal of the clamping module; a second terminal of the clamping module is connected to the gate of the power device; a first terminal of the buffer module is connected to the gate of the power device, and a second terminal of the buffer module is connected to the negative power supply; the driving module is used to drive and control the switching state of the power device; the detection module is used to detect the drain voltage change rate of the power device and convert the drain voltage change rate into a detection signal output to the clamping module; the buffer module is used to absorb positive voltage spikes at the gate of the power device to suppress positive crosstalk; and the clamping module is used to conduct a low-impedance path between the gate of the power device and the negative power supply to suppress negative crosstalk when the detection signal exceeds a preset value.

[0008] In one embodiment, the detection module includes: a direct sampling unit and a detection signal conversion unit; a first terminal of the direct sampling unit is connected to the drain of the power device, a second terminal of the direct sampling unit is connected to a negative power supply, and a third terminal of the direct sampling unit is connected to the first terminal of the detection signal conversion unit; the second terminal of the detection signal conversion unit is connected to the negative power supply, and the third terminal of the detection signal conversion unit is connected to the first terminal of the clamping module; the direct sampling unit is used to detect the drain voltage change rate of the power device, and converts the drain voltage change rate via the detection signal conversion unit and outputs a detection signal to the clamping module.

[0009] In one embodiment, the direct sampling unit includes: a first capacitor and a first resistor; a first terminal of the first capacitor is connected to the drain of the power device, and a second terminal of the first capacitor is connected to the first terminal of the first resistor and the first terminal of the detection signal conversion unit; the second terminal of the first resistor is connected to the negative power supply.

[0010] In one embodiment, the detection signal conversion unit includes: a first diode, a second resistor, and a third resistor; the anode of the first diode is connected to the third terminal of the direct sampling unit, and the cathode of the first diode is connected to the first terminal of the second resistor; the second terminal of the second resistor is connected to the first terminal of the clamping module and the first terminal of the third resistor, respectively; the second terminal of the third resistor is connected to a negative power supply.

[0011] In one embodiment, the buffer module includes: a second diode, a fourth resistor, and a second capacitor; the anode of the second diode is connected to the gate of the power device; the cathode of the second diode is connected to the first terminal of the fourth resistor and the first terminal of the second capacitor, respectively; the second terminal of the fourth resistor is connected to the second terminal of the second capacitor and the negative power supply terminal, respectively.

[0012] In one embodiment, the clamping module includes a discharge unit and a comparison unit; a first terminal of the comparison unit is connected to a third terminal of the detection module; a first terminal of the discharge unit is connected to the gate of the power device, a second terminal of the discharge unit is connected to a negative power supply, and a third terminal of the discharge unit is connected to a second terminal of the comparison unit; the comparison unit is used to compare the received detection signal with an internal preset value, and output a discharge signal to the discharge unit when the detection signal exceeds the preset value; the discharge unit is used to conduct a low-impedance path between the gate of the internal power device and the negative power supply to suppress negative crosstalk when it receives the discharge signal.

[0013] In one embodiment, the discharge unit includes: a first switching transistor; the gate of the first switching transistor is connected to the second terminal of the comparator unit, the drain of the first switching transistor is connected to the gate of the power device, and the source of the first switching transistor is connected to the negative power supply.

[0014] In one embodiment, the comparison unit includes: a comparator, a fifth resistor, a sixth resistor, and a seventh resistor; the resistance value of the sixth resistor is adjustable; the first terminal of the comparator is connected to the third terminal of the detection module; the first terminal of the fifth resistor is connected to a positive power supply, and the second terminal of the fifth resistor is connected to the second terminal of the comparator and the first terminal of the sixth resistor respectively; the second terminal of the sixth resistor is connected to a negative power supply; the third terminal of the comparator is connected to the first terminal of the seventh resistor; and the second terminal of the seventh resistor is connected to the third terminal of the discharge unit.

[0015] Secondly, this application provides a power conversion circuit, including at least one power device; the power device is driven by a crosstalk suppression circuit according to the first aspect.

[0016] Thirdly, this application provides a power conversion device that uses the power conversion circuit of the second aspect.

[0017] It is understood that the beneficial effects of the second and third aspects mentioned above can be found in the relevant descriptions in the first aspect above, and will not be repeated here.

[0018] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: This application solves the problem that existing power device crosstalk suppression drivers cannot simultaneously achieve switching performance and suppression effectiveness by integrating a driving module, a detection module, a buffer module, and a clamping module. Specifically, the driving module ensures the basic switching performance of the power device is unaffected by suppression actions; the detection module monitors the drain voltage change rate of the power device in real time and converts it into a detection signal, thereby identifying crosstalk risks in advance; the buffer module directly absorbs positive voltage spikes at the gate, suppressing positive crosstalk and preventing the power device from being turned on erroneously; when the detection signal exceeds a preset value, the clamping module automatically conducts a low-impedance path between the gate and the negative power supply, quickly pulling down the gate voltage to suppress negative crosstalk and prevent erroneous shutdown.

[0019] With this design, the real-time feedback from the detection module triggers the precise action of the clamping module, while the buffer module independently handles positive interference. This ensures that crosstalk suppression is activated only when needed, avoiding the switching delay caused by fixed buffers or clamps in traditional technologies. Thus, while maintaining high-speed switching performance, efficient crosstalk suppression is achieved, improving the reliability of the overall drive circuit. Attached Figure Description

[0020] Figure 1 This is one of the structural block diagrams of the crosstalk suppression driving circuit provided in the embodiments of this application; Figure 2 This is the second structural block diagram of the crosstalk suppression driving circuit provided in the embodiments of this application; Figure 3 This is a topology diagram of the crosstalk suppression driving circuit provided in the embodiments of this application; Figure 4 This is a topology diagram of the power conversion circuit provided in the embodiments of this application; In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 10 is the drive module; 20 is the detection module; 21 is the direct sampling unit; 22 is the detection signal conversion unit; 30 is the buffer module; 40 is the clamping module; 41 is the comparison unit; 42 is the discharge unit; Cf is the first capacitor; Rf is the first resistor; D1 is the first diode; R2 is the second resistor; R3 is the third resistor; D2 is the second diode; R4 is the fourth resistor; C2 is the second capacitor; Qn is the first switching transistor; U1 is the comparator; R5 is the fifth resistor; R6 is the sixth resistor; R7 is the seventh resistor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. In this application, the symbol " / " indicates that the related objects are in an "or" relationship, for example, A / B means A or B.

[0023] In this application, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0024] In this application, the term "connection" can refer to a direct circuit connection or a signal transmission via a communication protocol.

[0025] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0026] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0027] Currently, power device driving technology faces a core contradiction: the inability to simultaneously achieve high-speed switching performance and effective crosstalk suppression. The root of this problem lies in a direct physical conflict. Crosstalk is caused by the extremely high voltage change rate (dv / dt) during switching, and increasing switching speed requires increasing dv / dt. This creates a dilemma: reducing switching speed to suppress crosstalk leads to a sharp increase in switching losses, failing to leverage the high-frequency, high-efficiency advantages of third-generation semiconductors (such as SiC and GaN); conversely, increasing switching speed to pursue high performance exacerbates crosstalk, causing bridge arm mis-conduction and threatening system safety. Traditional solutions, such as simply increasing the turn-off gate resistance or using negative voltage turn-off, are compromises. They either sacrifice speed or only improve tolerance without eliminating the source of interference, ultimately failing to break the trade-off between performance and reliability.

[0028] Based on this, this application proposes a crosstalk suppression driving circuit, please refer to... Figure 1 , Figure 1 This is one of the structural block diagrams of the crosstalk suppression driving circuit provided in the embodiments of this application.

[0029] In this embodiment, the crosstalk suppression driving circuit includes: a driving module 10, a detection module 20, a buffer module 30, and a clamping module 40.

[0030] The first end of the driving module 10 is connected to the gate of the power device; the first end of the detection module 20 is connected to the drain of the power device; the second end of the detection module 20 is connected to the negative power supply; the third end of the detection module 20 is connected to the first end of the clamping module 40; the second end of the clamping module 40 is connected to the gate of the power device; the first end of the buffer module 30 is connected to the gate of the power device; and the second end of the buffer module 30 is connected to the negative power supply.

[0031] It should be noted that the power devices in this application refer to third-generation wide-bandgap semiconductor power devices, represented by silicon carbide (SiC) and gallium nitride (GaN). This also includes MOSFETs and IGBTs. These devices are widely used in power conversion circuits such as bridge circuits. Connecting to the negative power supply is primarily to provide a reference ground and an energy discharge path.

[0032] It should be noted that the drive module 10 is used to drive and control the switching state of the power devices.

[0033] Understandably, in a circuit system, the switching state of a power device directly affects the operating mode and performance of the entire circuit. The driver module 10 switches the power device between on and off states by applying a suitable voltage signal to its gate. For example, when the power device needs to be turned on to allow current to flow, the driver module 10 outputs a sufficiently high voltage to the gate, forming a conductive path inside the power device; conversely, when the power device needs to be turned off to block current, the driver module 10 outputs a lower voltage or zero voltage, causing the conductive path to disappear. This precise switching control is crucial for realizing various circuit functions, such as power conversion and signal amplification.

[0034] It should be noted that the detection module 20 is used to detect the drain voltage change rate of the power device and convert the drain voltage change rate into a detection signal output to the clamping module 40.

[0035] Understandably, during the operation of a power device, the drain voltage changes with the circuit's operating state, and its rate of change reflects the device's operating state and load conditions. The detection module 20, connected to the drain of the power device, can sense these changes in real time and convert them into a corresponding detection signal. For example, when the power device is switching, the drain voltage may rise or fall rapidly. The detection module 20 can capture this rapid voltage change and convert it into an electrical signal, which is then output to the clamping module 40. This detection signal provides the clamping module 40 with a basis for judgment, determining whether measures need to be taken to suppress crosstalk.

[0036] Specifically, this can be achieved using a drain voltage change rate detection circuit based on a voltage comparator. The voltage comparator compares the difference between the drain voltage and a reference voltage, and outputs a signal proportional to the drain voltage change rate. When the drain voltage change rate exceeds a preset threshold, the voltage comparator outputs a high-level signal, triggering the clamping module to operate.

[0037] It should be noted that the buffer module 30 is used to absorb the positive voltage spikes of the power device gate to suppress positive crosstalk.

[0038] Understandably, during the switching process of power devices, due to the presence of inductors and capacitors in the circuit, a positive voltage spike will be generated at the gate when the state of the power device changes rapidly. These voltage spikes may exceed the gate withstand voltage of the power device, leading to damage or performance degradation. The buffer module 30 provides a discharge path for positive voltage spikes by connecting the gate of the power device to the negative power supply. When a positive voltage spike occurs, the buffer module 30 can quickly absorb it and guide it to the negative power supply, thereby protecting the gate of the power device from overvoltage damage and effectively suppressing positive crosstalk.

[0039] Specifically, RC snubber circuits can be used to absorb positive voltage spikes at the gate of power devices. An RC snubber circuit consists of a resistor and a capacitor. When a positive voltage spike occurs at the gate, the capacitor charges rapidly, absorbing and storing the spike energy in the capacitor. Subsequently, the resistor slowly releases the energy in the capacitor, avoiding secondary interference to the circuit.

[0040] It should be noted that the clamping module 40 is used to conduct a low-impedance path between the gate of the power device and the negative power supply to suppress negative crosstalk when the detection signal exceeds a preset value.

[0041] Understandably, the function of the clamping module 40 is to establish a low-impedance path between the gate of the power device and the negative power supply when the detection signal exceeds a preset value, thereby suppressing negative crosstalk. When the detection module 20 detects an abnormal drain voltage change rate of the power device and transmits the corresponding detection signal to the clamping module 40, the clamping module 40 will judge the detection signal. If the detection signal exceeds a preset threshold, it indicates that the power device may be at risk of negative crosstalk. At this time, the clamping module 40 will quickly turn on, establishing a low-impedance path between the gate of the power device and the negative power supply.

[0042] Understandably, a low-impedance path means that current encounters less resistance when flowing along that path, allowing it to flow quickly and smoothly. This low-impedance path can quickly raise the negative voltage on the gate of the power device to a level close to the negative supply voltage, thereby preventing excessive negative voltage from damaging the power device and effectively suppressing negative crosstalk.

[0043] Specifically, an active clamp-based crosstalk suppression circuit can be used, which consists of active devices such as transistors or MOSFETs. When the detection signal exceeds a preset threshold, the clamping circuit quickly turns on to clamp the gate voltage of the power device within a safe range, preventing negative crosstalk from causing the device to mis-turn on or be damaged.

[0044] The system's collaborative workflow is illustrated using the upper half-bridge transistor as an example. First, consider the scenario where the lower half-bridge transistor is turned on and the upper half-bridge transistor is turned off: When the lower half-bridge transistor is turned on at high speed, the drain voltage of the upper half-bridge transistor drops rapidly from the bus voltage to 0V, forming an extremely high negative dv / dt. This voltage jump, through the coupling effect of the Miller capacitance, generates a positive voltage spike at the gate of the upper half-bridge transistor, i.e., positive crosstalk. At this time, the various modules of the system respond collaboratively: Although the detection module 20 detects the drastic negative change in the drain and generates a corresponding detection signal, its output signal is usually insufficient to reach the trigger threshold of the clamping module 40 because the voltage change direction is negative; while the buffer module 30 immediately takes effect, absorbing and discharging the positive voltage spike on the gate to the negative power supply through its internal path, effectively suppressing the abnormal rise in gate voltage and ensuring that it cannot reach the turn-on threshold of the power device, thus successfully avoiding the risk of mis-turn-on caused by positive crosstalk.

[0045] Next, we analyze the reverse scenario where the current transistor is off and the current transistor is on: When the current transistor is turned off at high speed, the drain voltage of the current transistor rises rapidly from 0V to the bus voltage, generating an extremely high positive dv / dt. This voltage change is also coupled through the Miller capacitance, generating a negative voltage spike at the gate of the current transistor, i.e., negative crosstalk. In this case, the system response mechanism is different: the detection module 20 accurately captures the positive voltage change at the drain, generates a detection signal with a significant amplitude, and transmits it to the clamping module 40; when this signal exceeds a preset threshold, the clamping module 40 immediately turns on, establishing a low-impedance path between the gate of the power device and the negative power supply; at this time, the buffer module 30, facing a negative voltage change, has a relatively limited effect. Ultimately, the low-impedance path provided by the clamping module 40 can inject compensation current into the gate, effectively offsetting the charge drawn by the Miller capacitance, stabilizing the gate voltage at the normal operating level, thereby ensuring that the power device remains fully on and achieving reliable suppression of negative crosstalk.

[0046] In this embodiment, by integrating the collaborative work of the driving module, detection module, buffer module, and clamping module, the problem that existing power device crosstalk suppression drivers cannot simultaneously achieve switching performance and suppression effect is solved. Specifically, the driving module ensures the basic switching performance of the power device, unaffected by suppression actions; the detection module monitors the drain voltage change rate of the power device in real time and converts it into a detection signal, thereby identifying crosstalk risks in advance; the buffer module directly absorbs the positive voltage spike of the gate, suppressing positive crosstalk and preventing the power device from being turned on erroneously; when the detection signal exceeds a preset value, the clamping module automatically conducts a low-impedance path between the gate and the negative power supply, quickly pulling down the gate voltage to suppress negative crosstalk and prevent erroneous shutdown.

[0047] With this design, the real-time feedback from the detection module triggers the precise action of the clamping module, while the buffer module independently handles positive interference. This ensures that crosstalk suppression is activated only when needed, avoiding the switching delay caused by fixed buffers or clamps in traditional technologies. Thus, while maintaining high-speed switching performance, efficient crosstalk suppression is achieved, improving the reliability of the overall drive circuit.

[0048] In addition, the crosstalk suppression drive circuit provided in this application aims to manufacture a highly reliable, energy-saving, and environmentally friendly integrated drive circuit or module through innovative circuit structure design. This circuit effectively solves the problems of false triggering and performance degradation caused by crosstalk during high-speed switching of power devices, thereby significantly improving the stability and efficiency of the power conversion system. This technological achievement will be directly applied to key equipment in smart grids, such as new energy inverters, flexible DC transmission devices, and intelligent distribution units. By reducing switching losses, increasing power density, and extending equipment lifespan, it provides core technological support for building a safe, efficient, and clean green smart grid industry, helping it to achieve high-quality development towards intelligence and low carbon emissions.

[0049] Furthermore, to achieve more flexible and diverse circuit construction methods and enhance the scalability and adaptability of circuit design, the detection module 20 and clamping module 40 in this application can be further subdivided. Through this subdivision, the units are interconnected in more diverse combinations, achieving the same crosstalk suppression function as the original circuit, thereby realizing the overall structure of the drive circuit. Please refer to... Figure 2 , Figure 2 This is the second structural block diagram of the crosstalk suppression driving circuit provided in the embodiments of this application.

[0050] In this embodiment, the detection module 20 includes a direct sampling unit 21 and a detection signal conversion unit 22.

[0051] The first end of the direct sampling unit 21 is connected to the drain of the power device, the second end of the direct sampling unit 21 is connected to the negative power supply, and the third end of the direct sampling unit 21 is connected to the first end of the detection signal conversion unit 22; the second end of the detection signal conversion unit 22 is connected to the negative power supply, and the third end of the detection signal conversion unit 22 is connected to the first end of the clamping module 40.

[0052] It should be noted that the direct sampling unit 21 is used to detect the drain voltage change rate of the power device, and converts the drain voltage change rate through the detection signal conversion unit 22 and outputs the detection signal to the clamping module 40.

[0053] Understandably, during the operation of power devices, the drain voltage fluctuates with changes in switching state. If this fluctuation exceeds the normal range, it may cause crosstalk problems. The direct sampling unit 21 can accurately capture the changes in drain voltage and record these changes as electrical signals, providing raw data for subsequent signal conversion and processing.

[0054] Specifically, the core of the direct sampling unit 21 is sensing the rate of voltage change. One of the most direct and common implementations is using a capacitor. The formula for the current flowing through the capacitor is i = C * dv / dt. When the drain voltage changes drastically (high dv / dt), a momentary pulse current flows through the capacitor. Therefore, a typical direct sampling unit 21 can be a capacitor connected between the drain and the conversion unit. This capacitor directly converts the drain voltage change into a current pulse. The larger the dv / dt, the stronger the generated current pulse. It could also be a small RC differentiator circuit, or an integrated high-voltage probe, etc.

[0055] Understandably, after receiving the drain voltage change information from the direct sampling unit 21, the detection signal conversion unit 22 will perform conversion processing. This conversion may involve converting the analog voltage change signal into a digital signal, or adjusting parameters such as the signal amplitude and frequency to better meet the input requirements of the clamping module 40. After conversion, the detection signal conversion unit 22 will output the processed detection signal to the clamping module 40, providing the clamping module 40 with an accurate basis for determining whether crosstalk suppression measures are needed.

[0056] Specifically, if the direct sampling unit 21 outputs a current pulse, the detection signal conversion unit 22 will convert it into a voltage signal. This is typically achieved using an operational amplifier or a simple resistor.

[0057] In this embodiment, the clamping module 40 includes a discharge unit 42 and a comparison unit 41.

[0058] The first end of the comparison unit 41 is connected to the third end of the detection module 20; the first end of the discharge unit 42 is connected to the gate of the power device, the second end of the discharge unit 42 is connected to the negative power supply, and the third end of the discharge unit 42 is connected to the second end of the comparison unit 41.

[0059] It should be noted that the comparison unit 41 is used to compare the received detection signal with an internal preset value, and output a discharge signal to the discharge unit 42 when the detection signal exceeds the preset value.

[0060] Understandably, when the comparison unit 41 receives the detection signal from the detection module 20 through the first terminal, it will immediately compare the detection signal with a pre-set standard value (preset value). This preset value is determined through extensive experiments and theoretical analysis, and it represents the reasonable range of the drain voltage change rate of the power device under normal operating conditions. If the value of the detection signal exceeds the preset value during the comparison process, it means that the power device may be malfunctioning, which could potentially cause crosstalk. At this time, the comparison unit 41 will quickly output a specific signal, namely the discharge signal, and transmit it to the discharge unit 42, informing the discharge unit 42 that it needs to take action to suppress crosstalk.

[0061] Specifically, the core of the comparator unit is typically a voltage comparator. It has two inputs: a non-inverting input (V+) and an inverting input (V-). The detection signal is applied to one of the inputs, such as the non-inverting input. An internal preset value is a stable reference voltage, usually generated by a reference voltage source, connected to the other input, such as the inverting input. This reference voltage is the threshold for determining the severity of crosstalk. When the detection signal voltage is below this preset value, the comparator outputs a state, such as a low level, indicating safety and no action is needed. When the detection signal voltage exceeds this preset value, the comparator immediately toggles its output state, for example, to a high level; this high-level signal is the discharge signal. This toggle is extremely fast, typically on the nanosecond scale, ensuring timely response.

[0062] It should be noted that the discharge unit 42 is used to conduct a low-impedance path between the gate of the internal power device and the negative power supply when a discharge signal is received, so as to suppress negative crosstalk.

[0063] Understandably, when it receives the discharge signal from the comparator unit 41, it will react quickly by opening a low-impedance path between the gate of its internal power device and the negative power supply, thereby changing the potential of the power device gate and suppressing the occurrence of negative crosstalk.

[0064] Specifically, the core of the bleeder unit is typically a high-power switching device, such as an NMOS transistor or a Darlington transistor. Under normal conditions, when there is no bleeder signal or the signal is low, this switching device is in the off state, exhibiting extremely high impedance between its drain and source, having almost no effect on normal gate drive. When it receives a bleeder signal from comparator unit 41, such as a high-level voltage, this switching device quickly turns on, establishing a path with extremely low resistance between the gate of the power device and the negative power supply.

[0065] Understandably, this low-impedance path can provide a huge transient current, which will quickly pull the charge that surges into the gate due to crosstalk and negative voltage spikes, or rather, the charge that is drawn away by the Miller capacitor, to the negative power source, thereby strongly clamping the gate voltage at a safe level and preventing it from dropping abnormally.

[0066] In this embodiment, the detection module 20 is divided into a direct sampling unit 21 and a detection signal conversion unit 22, which refines and specializes the functions of the detection module, improves the accuracy and flexibility of detection, and optimizes the circuit detection performance. The direct sampling unit 21 focuses on the direct acquisition of the drain voltage of the power device, ensuring the originality and accuracy of the data; the detection signal conversion unit 22 focuses on signal processing and conversion, making the signal more suitable for the needs of subsequent modules. This division allows each detection module to perform its own function, improving the overall detection efficiency. The clamping module 40 is divided into a discharge unit 42 and a comparison unit 41, which modularizes and refines the functions of the clamping module, enhances the timeliness and effectiveness of crosstalk suppression, and optimizes the overall circuit performance. The comparison unit 41 can quickly and accurately determine the crosstalk situation, while the discharge unit 42 can quickly perform suppression actions. The two work together to significantly improve the circuit's ability to cope with crosstalk.

[0067] Based on the above embodiments, this application provides specific implementation methods, please refer to them. Figure 3 , Figure 3 This is a topology diagram of the crosstalk suppression driving circuit provided in the embodiments of this application.

[0068] Specifically, the drive push-pull circuit of the drive module 10 is built using an isolated gate driver chip (such as ADI's ADUM4221) to output a drive voltage of +20V (VCC) and -5V (VEE).

[0069] In this embodiment, the direct sampling unit 21 includes: a first capacitor Cf and a first resistor Rf; the first end of the first capacitor Cf is connected to the drain of the power device, and the second end of the first capacitor Cf is connected to the first end of the first resistor Rf and the first end of the detection signal conversion unit 22 respectively; the second end of the first resistor Rf is connected to the negative power supply.

[0070] It should be noted that the first capacitor Cf is a high-voltage ceramic capacitor, Cf=10pF; the first resistor Rf is a 2Ω resistor. The first capacitor Cf blocks DC and passes AC to extract the AC variation component for initial sampling; together with the first resistor Rf, it forms an RC voltage divider circuit to adjust the signal amplitude. The other end of the first resistor Rf is connected to a negative power supply to provide a reference potential and limit current, ensuring stable and reliable sampling and providing accurate raw data for the circuit. Finally, the voltage at the detection point Vf between the first capacitor Cf and the first resistor Rf is approximately Vf=Rf*Cf*dv / dt+VEE.

[0071] In this embodiment, the detection signal conversion unit 22 includes: a first diode D1, a second resistor R2 and a third resistor R3; the anode of the first diode D1 is connected to the third terminal of the direct sampling unit 21, and the cathode of the first diode D1 is connected to the first terminal of the second resistor R2; the second terminal of the second resistor R2 is connected to the first terminal of the clamping module 40 and the first terminal of the third resistor R3 respectively; the second terminal of the third resistor R3 is connected to the negative power supply.

[0072] It should be noted that the anode of the first diode D1 is connected to the third terminal of the direct sampling unit 21, using its unidirectional conductivity to rectify and filter the signal; the second resistor R2 and the third resistor R3 together form a voltage divider circuit to adjust the signal amplitude; the other end of the third resistor R3 is connected to the negative power supply to provide a reference potential. This is used to divide the voltage at the detection point Vf to adapt to the input range of the comparator U1 in the subsequent comparison unit.

[0073] In this embodiment, the buffer module 30 includes: a second diode D2, a fourth resistor R4, and a second capacitor C2; the anode of the second diode D2 is connected to the gate of the power device; the cathode of the second diode D2 is connected to the first terminal of the fourth resistor R4 and the first terminal of the second capacitor C2 respectively; the second terminal of the fourth resistor R4 is connected to the second terminal of the second capacitor C2 and the negative power supply terminal respectively.

[0074] It should be noted that the second diode D21 is a fast recovery diode, and the parameters of the fourth resistor R4 and the second capacitor C2 are calculated and selected based on the bus voltage (600V) and peak current (25A) to absorb the turn-off overvoltage and suppress forward crosstalk.

[0075] In this embodiment, the comparison unit 41 includes: a comparator U1, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7; the resistance value of the sixth resistor R6 is adjustable; the first terminal of the comparator U1 is connected to the third terminal of the detection module 20; the first terminal of the fifth resistor R5 is connected to a positive power supply, and the second terminal of the fifth resistor R5 is connected to the second terminal of the comparator U1 and the first terminal of the sixth resistor R6 respectively; the second terminal of the sixth resistor R6 is connected to a negative power supply; the third terminal of the comparator U1 is connected to the first terminal of the seventh resistor R7; and the second terminal of the seventh resistor R7 is connected to the third terminal of the discharge unit 42.

[0076] It should be noted that the fifth resistor R5 and the sixth resistor R6 are used to set the reference voltage VREF, for example, to 1.5V. The resistance value of the sixth resistor R6 is adjustable, which can achieve process regulation. The seventh resistor R7 is used to protect the gate of the subsequent switching device to prevent excessive current from damaging the subsequent switching device.

[0077] In this embodiment, the discharge unit 42 includes: a first switching transistor Qn; the gate of the first switching transistor Qn is connected to the second terminal of the comparison unit 41, the drain of the first switching transistor Qn is connected to the gate of the power device, and the source of the first switching transistor Qn is connected to the negative power supply.

[0078] It should be noted that comparator U1 is a high-speed comparator, such as TLV3501, whose output drives the gate of a low-power first switching transistor Qn, such as 2N7002, through a resistor. The drain of the first switching transistor Qn is directly connected to the gate of the power device, and the source is connected to VEE.

[0079] Based on the above embodiments, this application also proposes a power conversion circuit, please refer to... Figure 4 , Figure 4 This is a topology diagram of the power conversion circuit provided in the embodiments of this application.

[0080] In this embodiment, the power conversion circuit includes at least one power device; the power device employs the crosstalk suppression driving circuit described above.

[0081] Specifically, in Figure 4 Based on this, during operation, when the current transistor (active transistor) QL is turned off and the current transistor (passive transistor) QH is turned on, the drain voltage of the upper transistor rises sharply, generating a high dv / dt. The voltage Vf subsequently increases. When Vf exceeds VREF, comparator U1 outputs a high level, turning on Qn. The conduction of Qn provides a low-impedance path (directly to VEE) for the coupling current flowing through the Miller capacitor of the upper transistor QH, preventing the entire current from flowing through the gate resistor and generating a large negative voltage spike. After the turn-off process ends, dv / dt decreases, Vf drops, and Qn turns off. Conversely, when the current transistor (active transistor) QL is turned on and the upper transistor (passive transistor) QH is turned off, the positive voltage spike is absorbed by the buffer module. Further details are omitted here. To verify the effectiveness of this invention, a dual-pulse test platform was built in LTSPICE simulation software (e.g., Figure 4 As shown in the figure, the bus voltage Vdc = 600V, the load current IL = 25A, and the load inductance L = 350μH. The performance of the conventional driver (Condition I), the RCD buffer only (Condition II), and the RCD-GPC driver of this invention (Condition III) were compared under three different gate resistors (Rg = 5Ω, 10Ω, 15Ω).

[0082] The specific peak and peak parameters are summarized in the table below:

[0083] It can be observed that under the conventional drive (I), the turn-off voltage spike and the negative crosstalk voltage spike (Vgs_H) are the most severe. Using only RCD (II) has limited effect on suppressing the turn-off voltage spike, and its effect on suppressing negative crosstalk is poor (and may even be aggravated by loop changes). After adopting the present invention (III), both the turn-off voltage spike and the negative crosstalk voltage spike are significantly suppressed. Data shows that under different RG values, the circuit of the present invention can reduce the turn-off voltage spike by an average of about 59.5% and the negative crosstalk voltage spike by an average of about 86.6%, which is far superior to the previous two solutions.

[0084] Furthermore, based on the above, this application also proposes a power conversion device that uses the power conversion circuit described above.

[0085] Specifically, this power conversion device effectively utilizes its crosstalk suppression capability by applying this power conversion circuit. During device operation, when voltage spikes and crosstalk issues arise in the power devices during high-speed switching, the drive circuit can respond instantly: the detection module monitors the voltage change rate of the power device drain in real time, the buffer module actively absorbs positive voltage spikes to suppress positive crosstalk, and the clamping module quickly establishes a low-impedance path between the gate and the negative power supply when it detects excessively high voltage changes, thereby effectively suppressing negative crosstalk.

[0086] This design enables the power conversion device to significantly improve system reliability and stability while maintaining high power conversion efficiency. Especially in high-frequency switching applications, such as switching power supplies, inverters, and motor drives, it can effectively prevent problems such as mis-conduction or insufficient drive of power devices caused by crosstalk, reduce electromagnetic interference, and improve overall performance and service life, which will not be elaborated further here.

[0087] It should be understood that expressions such as “comprising” and “may include” used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as “comprising” and / or “having” are to be interpreted as indicating a particular characteristic, number, operation, constituent element, component, or combination thereof, but not to exclude the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0088] Furthermore, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0089] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after connection. "Rotary connection" refers to a connection where the components can rotate relative to each other after connection. "Sliding connection" refers to a connection where the components can slide relative to each other after connection. The directional terms mentioned in the embodiments of this application, such as "top," "bottom," "inner," "outer," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0090] Furthermore, the mathematical concepts mentioned in the embodiments of this application, such as symmetry, equality, parallelism, and perpendicularity, are limitations specific to the current technological level, rather than absolute and strict mathematical definitions. Slight deviations are permissible; approximations of symmetry, equality, parallelism, and perpendicularity are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. "A and B are perpendicular" means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0091] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A crosstalk suppression driving circuit, characterized in that, include: The module consists of a driver module, a detection module, a buffer module, and a clamping module. The first end of the driving module is connected to the gate of the power device; the first end of the detection module is connected to the drain of the power device; the second end of the detection module is connected to the negative power supply; the third end of the detection module is connected to the first end of the clamping module; the second end of the clamping module is connected to the gate of the power device; the first end of the buffer module is connected to the gate of the power device; and the second end of the buffer module is connected to the negative power supply. The drive module is used to drive and control the switching state of the power devices; The detection module is used to detect the drain voltage change rate of the power device and convert the drain voltage change rate into a detection signal and output it to the clamping module. The buffer module is used to absorb the positive voltage spikes at the gate of the power device to suppress positive crosstalk. The clamping module is used to conduct a low-impedance path between the gate of the power device and the negative power supply to suppress negative crosstalk when the detection signal exceeds a preset value.

2. The crosstalk suppression driving circuit as described in claim 1, characterized in that, The detection module includes: a direct sampling unit and a detection signal conversion unit; The first end of the direct sampling unit is connected to the drain of the power device, the second end of the direct sampling unit is connected to the negative power supply, and the third end of the direct sampling unit is connected to the first end of the detection signal conversion unit. The second end of the detection signal conversion unit is connected to the negative power supply, and the third end of the detection signal conversion unit is connected to the first end of the clamping module. The direct sampling unit is used to detect the drain voltage change rate of the power device, and converts the drain voltage change rate via the detection signal conversion unit and outputs the detection signal to the clamping module.

3. The crosstalk suppression driving circuit as described in claim 2, characterized in that, The direct sampling unit includes: a first capacitor and a first resistor; The first terminal of the first capacitor is connected to the drain of the power device, and the second terminal of the first capacitor is connected to the first terminal of the first resistor and the first terminal of the detection signal conversion unit, respectively. The second end of the first resistor is connected to a negative power source.

4. The crosstalk suppression driving circuit as described in claim 2, characterized in that, The detection signal conversion unit includes: a first diode, a second resistor, and a third resistor; The anode of the first diode is connected to the third terminal of the direct sampling unit, and the cathode of the first diode is connected to the first terminal of the second resistor; The second end of the second resistor is connected to the first end of the clamping module and the first end of the third resistor, respectively; the second end of the third resistor is connected to the negative power supply.

5. The crosstalk suppression driving circuit as described in claim 1, characterized in that, The buffer module includes: a second diode, a fourth resistor, and a second capacitor; The anode of the second diode is connected to the gate of the power device; the cathode of the second diode is connected to the first terminal of the fourth resistor and the first terminal of the second capacitor, respectively. The second terminal of the fourth resistor is connected to the second terminal of the second capacitor and the negative power supply, respectively.

6. The crosstalk suppression driving circuit as described in claim 1, characterized in that, The clamping module includes: a discharge unit and a comparison unit; The first end of the comparison unit is connected to the third end of the detection module; The first terminal of the bleeder unit is connected to the gate of the power device, the second terminal of the bleeder unit is connected to the negative power supply, and the third terminal of the bleeder unit is connected to the second terminal of the comparator unit. The comparison unit is used to compare the received detection signal with an internal preset value, and output a discharge signal to the discharge unit when the detection signal exceeds the preset value; The discharge unit is used to conduct a low-impedance path between the gate of the internal power device and the negative power supply when a discharge signal is received, so as to suppress negative crosstalk.

7. The crosstalk suppression driving circuit as described in claim 6, characterized in that, The discharge unit includes: a first switching transistor; The gate of the first switching transistor is connected to the second terminal of the comparator unit, the drain of the first switching transistor is connected to the gate of the power device, and the source of the first switching transistor is connected to the negative power supply.

8. The crosstalk suppression driving circuit as described in claim 6, characterized in that, The comparison unit includes: a comparator, a fifth resistor, a sixth resistor, and a seventh resistor; The resistance value of the sixth resistor is adjustable; The first end of the comparator is connected to the third end of the detection module; The first end of the fifth resistor is connected to a positive power supply, and the second end of the fifth resistor is connected to the second end of the comparator and the first end of the sixth resistor, respectively; the second end of the sixth resistor is connected to a negative power supply. The third terminal of the comparator is connected to the first terminal of the seventh resistor; the second terminal of the seventh resistor is connected to the third terminal of the bleeder unit.

9. A power conversion circuit, characterized in that, It includes at least one power device; the power device employs a drive circuit for crosstalk suppression as described in any one of claims 1 to 8.

10. A power conversion device, characterized in that, The device uses the power conversion circuit as described in claim 9.

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