Voltage stress detection circuit and method, power conversion circuit, electronic device

Abstract

The present application discloses a voltage stress detection circuit and method, a power conversion circuit, and an electronic device. Among them, the voltage stress detection circuit includes: a charging regulation circuit configured to be coupled to a switching transistor; a first energy storage circuit coupled to the charging regulation circuit and configured to be coupled to a main control circuit. The charging regulation circuit is configured to obtain a switching voltage signal of the switching transistor and use the switching voltage signal to store energy in the first energy storage circuit. The first energy storage circuit is configured to output its current first energy storage voltage to the main control circuit so that the main control circuit adjusts a drive control signal sent to the switching transistor in response to the first energy storage voltage. By the above method, the voltage stress detection circuit in the present application can monitor the voltage stress of the switching transistor in the switching regulation circuit in real time, effectively avoid excessive voltage stress by timely adjusting the drive control signal sent to the switching transistor, and can also be helpful for product reliability analysis and improvement through recording.

Description

Technical Field

[0001] The present application relates to the technical field of circuit signal processing, and in particular, to a voltage stress detection circuit and method, a power conversion circuit, and an electronic device. Background Art

[0002] Nowadays, with the increasing abundance of electronic and mechanical products on the market, various types of signal function circuits are becoming more and more complex, and power semiconductors are usually important and indispensable devices. In the circuit design stage of related products, the voltage stress, current stress, power consumption, etc. of power semiconductors need to be calculated rigorously. Even in the later product debugging stage, comprehensive tests and repeated parameter optimization are required to ensure that the stress of the semiconductor does not exceed the limit. Especially for voltage stress, when the power transistor switches, a huge voltage spike can be generated across its two ends. If no effective measures are taken, once the instantaneous voltage stress exceeds the rated voltage value, it is very easy to break down the power transistor, resulting in irreversible failure and even burnout.

[0003] To suppress the voltage stress of power semiconductors, a voltage spike absorption circuit is generally added to the power transistor. This measure is very effective in improving the voltage stress problem under known working conditions. However, after all, the voltage spike absorption circuit is a passive action and is often insufficient in some unknown extreme situations. And the voltage spike absorption circuit is tested based on the known working conditions of the circuit to suppress the voltage stress under the known working conditions, which is based on the test results. However, in mass production applications, when the circuit parameters are abnormal or there are other unknown working conditions, it is often unknown whether the voltage stress meets the requirements. When serious device damage occurs, it is basically very difficult to analyze that the device is damaged by voltage stress, and it is even more impossible to judge whether there is voltage stress abnormality during circuit application, which is not beneficial to the improvement of product quality and the improvement of product design schemes. Summary of the Invention

[0004] The main technical problem to be solved by the present application is to provide a voltage stress detection circuit and method, a power conversion circuit, and an electronic device, which can solve the problem that the existing voltage spike absorption circuit cannot effectively improve the voltage stress problem when the circuit parameters are abnormal or there are other unknown working conditions, cannot effectively cope with some unknown extreme situations, and when serious device damage occurs, it is impossible to analyze that the device is damaged by voltage stress, and it is even more impossible to judge whether there is voltage stress abnormality during circuit application, which is not beneficial to the improvement of product quality and the improvement of product design schemes.

[0005] To solve the above technical problems, a technical solution adopted by this application is: to provide a voltage stress detection circuit, which is applied to the voltage stress detection of a switching regulation circuit. The switching regulation circuit includes a main control circuit and a switching transistor controlled by the main control circuit. Among them, the voltage stress detection circuit includes: a charging regulation circuit, which is used to be coupled to the switching transistor; a first energy storage circuit, which is coupled to the charging regulation circuit and is used to be coupled to the main control circuit; among them, the charging regulation circuit is configured to obtain the switching voltage signal of the switching transistor and use the switching voltage signal to store energy in the first energy storage circuit; the first energy storage circuit is configured to output its current first energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the first energy storage voltage.

[0006] Among them, the voltage stress detection circuit further includes a voltage division regulation circuit and a second energy storage circuit. The voltage division regulation circuit is coupled to the first energy storage circuit and the second energy storage circuit. The second energy storage circuit is used to be coupled to the main control circuit; among them, the voltage division regulation circuit is configured to receive the first energy storage voltage of the first energy storage circuit, perform voltage division regulation on the first energy storage voltage, and use the voltage-divided and regulated first energy storage voltage to store energy in the second energy storage circuit; the second energy storage circuit is configured to output its current second energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal in response to the second energy storage voltage.

[0007] Among them, the voltage stress detection circuit further includes a signal processing circuit. The signal processing circuit is coupled to the second energy storage circuit and is used to be coupled to the main control circuit;

[0008] Among them, the signal processing circuit is configured to receive the second energy storage voltage of the second energy storage circuit, compare the second energy storage voltage with a first preset threshold and a second preset threshold respectively to obtain a first comparison result and a second comparison result, and send a first warning signal or a second warning signal to the main control circuit correspondingly in response to the first comparison result and the second comparison result, so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the first warning signal, or stops sending the drive control signal in response to the second warning signal; where the first preset threshold is less than the second preset threshold.

[0009] Among them, the voltage stress detection circuit further includes a signal processing circuit, which is coupled to the second energy storage circuit and is used to be coupled to the main control circuit; wherein, the signal processing circuit is configured to receive the second energy storage voltage of the second energy storage circuit, calculate the first energy storage voltage by using a set function for the second energy storage voltage, compare the calculated first energy storage voltage with a third preset threshold to obtain a third comparison result, and send a voltage feedback signal or a third warning signal to the main control circuit correspondingly in response to the third comparison result, so that the main control circuit normally sends a drive control signal in response to the voltage feedback signal, or reduces the duty cycle or signal frequency of the drive control signal in response to the third warning signal, or stops sending the drive control signal.

[0010] Among them, the voltage stress detection circuit further includes a filtering circuit, which is coupled to the second energy storage circuit and is used to be coupled to the main control circuit; the filtering circuit is configured to receive the second energy storage voltage of the second energy storage circuit, perform filtering adjustment on the second energy storage voltage, and output it to the main control circuit, so that the main control circuit adjusts the drive control signal in response to the filtered second energy storage voltage.

[0011] Among them, the voltage stress detection circuit further includes an isolation circuit, which is coupled to the second energy storage circuit and is used to be coupled to the main control circuit; the isolation circuit is configured to receive the second energy storage voltage of the second energy storage circuit, perform isolation adjustment on the second energy storage voltage, and output it to the main control circuit, so that the main control circuit adjusts the drive control signal in response to the isolated second energy storage voltage.

[0012] Among them, the voltage stress detection circuit further includes a differential input isolation operational amplifier circuit, which is coupled to the isolation circuit, and the isolation circuit is used to cooperate with the differential input isolation operational amplifier circuit to perform isolation adjustment on the second energy storage voltage.

[0013] Among them, the charging regulation circuit includes a first diode and a first resistor, the first energy storage circuit includes a first capacitor, the voltage division regulation circuit includes a second resistor, a third resistor and a second diode, and the second energy storage circuit includes a second capacitor; wherein, the first end of the first diode is used to be coupled to the switching tube, the second end of the first diode is coupled to the first end of the first resistor, the second end of the first resistor is coupled to the first end of the first capacitor and the first end of the second resistor, the second end of the first capacitor is coupled to the second end of the third resistor, the second end of the second capacitor and grounded, the second end of the second resistor is coupled to the first end of the third resistor and the first end of the second diode, and the second end of the second diode is coupled to the first end of the second capacitor and is used to be coupled to the main control circuit.

[0014] Among them, the voltage stress detection circuit further includes a gating circuit. The number of switching transistors and the number of charge regulation circuits are equal and at least two. The gating circuit is coupled to each charge regulation circuit and is used to be coupled to each switching transistor, so as to cyclically and alternately couple each switching transistor to its corresponding charge regulation circuit at intervals of a set time duration.

[0015] To solve the above technical problems, another technical solution adopted by this application is: to provide a voltage stress detection method, among which, the voltage stress detection method includes: obtaining a switching voltage signal of a switching transistor; obtaining a first energy storage voltage by using the switching voltage signal; outputting the first energy storage voltage to a main control circuit, so that the main control circuit adjusts a drive control signal sent to the switching transistor in response to the first energy storage voltage.

[0016] Among them, after the step of obtaining the first energy storage voltage by using the switching voltage signal and before the step of outputting the first energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the first energy storage voltage, it further includes: performing voltage division adjustment on the first energy storage voltage; obtaining a second energy storage voltage by using the first energy storage voltage after voltage division adjustment; the step of outputting the first energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the first energy storage voltage includes: outputting the second energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the second energy storage voltage.

[0017] Among them, after the step of obtaining the second energy storage voltage by using the first energy storage voltage after voltage division adjustment and before the step of outputting the second energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the second energy storage voltage, it further includes: detecting whether the second energy storage voltage is greater than a first preset threshold; if the second energy storage voltage is greater than the first preset threshold, detecting whether the second energy storage voltage is greater than a second preset threshold; the step of outputting the second energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the second energy storage voltage includes: if the second energy storage voltage is not greater than the second preset threshold, sending a first warning signal to the main control circuit, so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the first warning signal; if the second energy storage voltage is greater than the second preset threshold, sending a second warning signal to the main control circuit, so that the main control circuit stops sending the drive control signal in response to the second warning signal.

[0018] After the step of obtaining the second energy storage voltage by using the first energy storage voltage adjusted by voltage division, before the step of outputting the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the second energy storage voltage, the method further includes: calculating the first energy storage voltage by using a set function for the second energy storage voltage; detecting whether the calculated first energy storage voltage is greater than a third preset threshold; the step of outputting the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the second energy storage voltage includes: if the calculated first energy storage voltage is greater than the third preset threshold, sending a third warning signal to the main control circuit so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the third warning signal, or stops sending the drive control signal.

[0019] To solve the above technical problem, another technical solution adopted by this application is: providing a power conversion circuit, wherein the power conversion circuit includes a switching regulation circuit and a voltage stress detection circuit which are coupled to each other; wherein, the voltage stress detection circuit is the voltage stress detection circuit described in any one of the above.

[0020] To solve the above technical problem, another technical solution adopted by this application is: providing an electronic device, wherein the electronic device includes a housing and a signal function circuit connected to the housing; wherein, the signal function circuit is the voltage stress detection circuit described in any one of the above, or the power conversion circuit described above.

[0021] The beneficial effect of this application is: different from the prior art, the charging regulation circuit in the voltage stress detection circuit provided by this application is used to be coupled to the switching transistor in the switching regulation circuit, and the first energy storage circuit is coupled to the charging regulation circuit and is used to be coupled to the main control circuit in the switching regulation circuit; wherein, the charging regulation circuit is configured to obtain the switching voltage signal of the switching transistor and use the switching voltage signal to store energy in the first energy storage circuit; the first energy storage circuit is configured to output its current first energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the first energy storage voltage, thereby being able to effectively monitor the voltage stress of the switching transistor in the switching regulation circuit in real time, and when it is detected that the voltage stress is abnormal, it is also possible to avoid excessive power consumption and affect the life of the switching transistor, or even irreversible failure and burning by timely adjusting the drive control signal sent to the switching transistor, thereby effectively avoiding the over-standard of voltage stress, and being able to record this event when the voltage stress is too high, which is also very helpful for the reliability analysis and improvement of the product; and whether the switching regulation circuit is in a known working condition, or the circuit parameters are abnormal or in other unknown working conditions, it is possible to effectively monitor whether the voltage stress is abnormal and take effective measures, which is helpful for the improvement of product quality and the improvement of product design solutions. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0023] Figure 1 is a schematic structural diagram of the first embodiment of the voltage stress detection circuit of the present application;

[0024] Figure 2 is a schematic structural diagram of the second embodiment of the voltage stress detection circuit of the present application;

[0025] Figure 3 is Figure 2 a schematic structural diagram of an embodiment of the switch adjustment circuit in

[0026] Figure 4 is Figure 3 a waveform diagram of the switching voltage signals of each switching transistor in the switch adjustment circuit in

[0027] Figure 5 is a schematic structural diagram of the third embodiment of the voltage stress detection circuit of the present application;

[0028] Figure 6 is a schematic structural diagram of the fourth embodiment of the voltage stress detection circuit of the present application;

[0029] Figure 7 is a schematic structural diagram of the fifth embodiment of the voltage stress detection circuit of the present application;

[0030] Figure 8 is a schematic structural diagram of the sixth embodiment of the voltage stress detection circuit of the present application;

[0031] Figure 9 is a schematic structural diagram of the seventh embodiment of the voltage stress detection circuit of the present application;

[0032] Figure 10 is a schematic flowchart of the first embodiment of the voltage stress detection method of the present application;

[0033] Figure 11 is a schematic flowchart of the second embodiment of the voltage stress detection method of the present application;

[0034] Figure 12 is a schematic flowchart of the third embodiment of the voltage stress detection method of the present application;

[0035] Figure 13 is a schematic flowchart of the fourth embodiment of the voltage stress detection method of the present application;

[0036] Figure 14 is a schematic structural diagram of an embodiment of the power conversion circuit of the present application;

[0037] Figure 15 is a schematic structural diagram of an embodiment of the electronic device of the present application. Specific Embodiments

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0039] The terms "first", "second", and "third" in the present application are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", and "third" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0040] Referring to "embodiment" herein means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0041] The present application will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0042] Please refer to Figure 1 , Figure 1It is a schematic structural diagram of the first embodiment of the voltage stress detection circuit of the present application. In this embodiment, the voltage stress detection circuit 10 specifically includes a charging regulation circuit 11 and a first energy storage circuit 12.

[0043] Among them, a voltage stress detection circuit 10 provided in the present application is specifically applied to the voltage stress detection of a power semiconductor device, to monitor the switching voltage signal of the switching tube 202 in the switching regulation circuit 200 in real time, and to perform feedback regulation on the switching tube 202 in response to a possible voltage stress anomaly, effectively avoiding excessive power consumption of the switching tube 202, affecting its lifespan, or even irreversible failure and burnout. Of course, in other embodiments, the voltage stress detection circuit 10 can also be specifically used in the voltage stress detection of a totem pole conversion circuit, a boost conversion circuit, a buck conversion circuit, or any other reasonable signal function circuit integrated with a power semiconductor device. This embodiment does not limit this.

[0044] Specifically, the switching regulation circuit 200 includes a main control circuit 201 and at least one switching tube 202 coupled to the main control circuit 201. Each switching tube 202 is controlled by the main control circuit 201, and the main control circuit 201 can specifically adjust the drive control signal output to the switching tube 202 to change the switching state of the switching tube 202, thereby adjusting the output voltage and / or output current of each circuit unit composed of each switching tube 202, while adjusting the switching power of each switching tube 202, or performing wave blocking protection on each switching tube 202.

[0045] In some embodiments, the switching tube 202 can specifically be one of any reasonable power semiconductor devices such as MOS (Metal Oxide Semiconductor Field Effect Transistor), high-frequency transistor, triode, thyristor, IGBT (Insulated Gate Bipolar Transistor), etc. The present application does not limit this.

[0046] In some embodiments, the main control circuit 201 can specifically include one or more of any reasonable circuit units with signal processing functions such as a control chip, MCU (Micro Controller Unit) circuit, CPU (Central Processing Unit), DSP (Digital Signal Processing), single-chip microcomputer, field programmable gate array, programmable logic device, discrete gate or transistor logic device, discrete hardware, etc. The present application does not limit this.

[0047] In some embodiments, the drive control signal may specifically be one or more of any reasonable control signals such as a PWM (Pulse Width Modulation) signal or a PFM (Pulse Frequency Modulation) signal, and the present application does not limit this.

[0048] It should be noted that when the first end of the switching transistor 202 is the control end and the drive control signal sent by the main control circuit 201 is received at the first end of the switching transistor 202, it can be triggered to conduct or turn off its second end and third end in response to the drive control signal.

[0049] In addition, "coupled" herein refers to including any direct and indirect connection means. Therefore, if it is described in the text that the first circuit is coupled to the second circuit, it means that the first circuit can be directly connected to the second circuit through electrical connection, wireless transmission, optical transmission and other signal connection methods, or indirectly electrically connected or signal connected to the second circuit through other circuits or connection means.

[0050] Among them, the charging regulation circuit 11 is used to be coupled to the switching transistor 202, and specifically may be connected to the second end and / or the third end of the switching transistor 202 to obtain the switching voltage signals of the second end and the third end of the switching transistor 202.

[0051] The first energy storage circuit 12 is coupled after the charging regulation circuit 11 and is connected to the main control circuit 201, and is used to store the electric energy from the charging regulation circuit 11 and convert it into a first energy storage voltage that can be read by the main control circuit 201.

[0052] Among them, the charging regulation circuit 11 is used to obtain the switching voltage signal of the switching transistor 202 and start charging the first energy storage circuit 12 by using the switching voltage signal. The first energy storage circuit 12 gradually accumulates energy, and its voltage level, that is, the first energy storage voltage, reflects the maximum voltage stress in the most recent switching event.

[0053] The main control circuit 201 detects and reads the first energy storage voltage, evaluates the working state of the current switching transistor 202 based on this, and determines whether it is necessary to adjust the drive control signal sent to the switching transistor 202 according to a preset safety threshold.

[0054] Among them, if the main control circuit 201 detects that the first energy storage voltage exceeds the set safety range, it indicates that the switching transistor 202 is subjected to excessive voltage stress. The main control circuit 201 can take measures to reduce the load, power, slow down the switching speed or temporarily stop the switching operation. For example, reduce the duty cycle and / or signal frequency of the drive control signal sent to the switching transistor 202, or directly block the drive control signal, that is, do not send the drive control signal to the switching transistor 202, to protect the switching transistor 202 from damage. Conversely, if it is detected that the first energy storage voltage is within the safety range, the main control circuit 201 can maintain the normal drive control strategy.

[0055] It can be understood that the voltage stress detection circuit 10 can effectively monitor and record the voltage stress condition of the corresponding switching transistor 202, and quickly feedback it to the main control circuit 201, realizing the real-time monitoring of the voltage stress. And by accurately measuring the transient voltage change across the switching transistor 202, the accuracy of the voltage stress evaluation is ensured. The entire detection process does not interfere with the normal operation of the original switching regulation circuit 200, avoiding the additional introduced noise or error. The main control circuit 201 can flexibly adjust the drive control strategy according to actual needs, improving the adaptability and reliability of the system. Compared with complex external monitoring devices, this built-in voltage stress detection scheme has a simple structure and is easy to integrate, reducing the overall system cost. Application scenarios This voltage stress detection circuit 10 is particularly suitable for various switching regulation circuits 200, especially those application scenarios with strict requirements for power semiconductor devices, such as motor drivers, on-vehicle chargers, DC-DC (Direct Current) converters, etc. in new energy vehicles. By introducing such a circuit, not only can the power device be effectively prevented from failing due to excessive voltage stress, but also valuable data support can be provided for subsequent product reliability analysis. In short, this voltage stress detection circuit 10 realizes the efficient and accurate monitoring of the voltage stress of the switching transistor 202 through the cooperation of the charging regulation circuit 11 and the first energy storage circuit 12. It not only helps to improve the overall performance and reliability of the switching regulation circuit 200, but also provides a solid foundation for future intelligent control and fault diagnosis.

[0056] In the above solution, by monitoring the voltage stress of the switching transistor 202 in the switching regulation circuit 200 in real time, and when an abnormal voltage stress is detected, it is also possible to adjust the drive control signal output to the switching transistor 202 in a timely manner, so as to avoid excessive power consumption of the switching transistor 202, affecting its lifespan, or even irreversible failure or burnout, thereby effectively avoiding excessive voltage stress and being able to record this event when the voltage stress is too high, which is also very helpful for product reliability analysis and improvement; and regardless of whether the switching regulation circuit 200 is in a known operating condition, or the circuit parameters are abnormal or in other unknown operating conditions, it is possible to effectively monitor whether the voltage stress is abnormal and take effective countermeasures, which helps to improve the product quality and the product design scheme.

[0057] Please refer to Figure 2 , Figure 2 FIG. is a schematic structural diagram of the second embodiment of the voltage stress detection circuit of the present application. The difference between the voltage stress detection circuit in this embodiment and the first embodiment of the voltage stress detection circuit provided by the present application is that the voltage stress detection circuit 20 specifically further includes a voltage division and regulation circuit 23 and a second energy storage circuit 24.

[0058] The voltage division and regulation circuit 23 is coupled between the first energy storage circuit 22 and the second energy storage circuit 24, and the second energy storage circuit 24 is coupled after the voltage division and regulation circuit 23 and is connected to the main control circuit 201.

[0059] Among them, the voltage division and regulation circuit 23 is used to receive the first energy storage voltage of the first energy storage circuit 22 and perform voltage division and regulation on it, and specifically can reduce the amplitude of the first energy storage voltage according to a preset ratio or dynamic adjustment strategy to ensure that the voltage transmitted to the main control circuit 201 is within a safe range and avoid damage to the main control circuit 201 caused by excessive voltage; and the voltage after voltage division and regulation will be transmitted to the second energy storage circuit 24 for energy storage.

[0060] The second energy storage circuit 24 receives and stores the first energy storage voltage after voltage division and regulation and gradually accumulates energy, and its voltage level, that is, the second energy storage voltage, reflects the voltage stress condition of the switching transistor 202.

[0061] The main control circuit 201 detects and reads the second energy storage voltage, and evaluates the current working state of the switching transistor 202 accordingly, so as to judge whether it is necessary to adjust the drive control signal sent to the switching transistor 202 according to a preset safety threshold.

[0062] Among them, if the main control circuit 201 detects that the second energy storage voltage exceeds the set safety range, it indicates that the switching transistor 202 is subjected to excessive voltage stress. The main control circuit 201 can take measures to reduce the load, slow down the switching speed, or temporarily stop the switching operation to protect the switching transistor 202 from damage. On the contrary, if it is detected that the second energy storage voltage is within the safety range, the main control circuit 201 can maintain the normal drive control strategy.

[0063] It is worth noting that the safety ranges of the voltage stresses corresponding to the drive control strategies set by the main control circuit 201 based on the first energy storage voltage and the second energy storage voltage are different. And since the second energy storage voltage is obtained by voltage division regulation of the first energy storage voltage, the second energy storage voltage and the first energy storage voltage will satisfy a specific functional relationship; correspondingly, the safety ranges of the voltage stresses corresponding to the first energy storage voltage and the second energy storage voltage also satisfy a specific functional relationship.

[0064] It can be understood that through the two-stage energy storage mechanism of the first energy storage circuit 22 and the second energy storage circuit 24, multi-level monitoring and protection of the voltage stress of the switching transistor 202 are realized. The voltage division regulation circuit 23 ensures that the voltage transmitted to the main control circuit 201 is within the safety range, avoiding the potential threat of direct high voltage to the main control circuit 201. The voltage signal after voltage division regulation is more stable and accurate, which helps to improve the accuracy and stability of voltage stress evaluation.

[0065] In some embodiments, the voltage stress detection circuit 20 specifically further includes a signal processing circuit 26, which is coupled after the second energy storage circuit 24 and connected to the main control circuit 201. The signal processing circuit 26 is used to receive the second energy storage voltage of the second energy storage circuit 24 and compare it with a preset threshold to generate a corresponding warning signal.

[0066] Specifically, the signal processing circuit 26 compares the second energy storage voltage with a first preset threshold and a second preset threshold respectively to obtain a first comparison result and a second comparison result. Among them, if the signal processing circuit 26 detects that the second energy storage voltage exceeds the first preset threshold but does not exceed the second preset threshold, the first comparison result is triggered, and the signal processing circuit 26 sends a first warning signal to the main control circuit 201; and if it is detected that the second energy storage voltage exceeds the second preset threshold, the second comparison result is triggered, and the signal processing circuit 26 sends a second warning signal to the main control circuit 201.

[0067] After receiving the first warning signal, the main control circuit 201 takes preventive measures, such as reducing the duty cycle of the drive control signal or reducing the signal frequency, to reduce the voltage stress of the switching transistor 202; and after receiving the second warning signal, it immediately stops sending the drive control signal to prevent the switching transistor 202 from being damaged due to excessive voltage stress.

[0068] It should be noted that the first preset threshold is less than the second preset threshold, which can be understood as a lower safety threshold indicating a slight over - standard voltage stress; while the second preset threshold is a higher danger threshold indicating a severe over - standard voltage stress.

[0069] In other embodiments, the signal processing circuit 26 may specifically be set with a larger number of preset thresholds. For example, the first preset threshold may specifically have at least two with different magnitudes, so as to perform more detailed feedback regulation on different over - standard voltage stress situations in a hierarchical manner, that is, hierarchically adjust and control the duty cycle of the drive control signal or reduce the signal frequency. The present application does not limit this.

[0070] In other embodiments, when the signal processing circuit 26 detects that the second energy storage voltage is less than the first preset threshold, it may specifically not send a signal to the main control circuit 201, or send a voltage feedback signal to the main control circuit 201 for sampling and recording, but does not adjust the current drive control signal. The present application does not limit this.

[0071] In other embodiments, the signal processing circuit 26 may specifically be integrated in the main control circuit 201, or the signal processing function specifically implemented by the signal processing circuit 26 may specifically be executed by the main control circuit 201. The present application does not limit this.

[0072] It can be understood that by setting different preset thresholds, intelligent identification and response to different levels of over - standard voltage stress are achieved, improving the safety of the system. The first warning signal allows the system to take mild protection measures in the early stage, while the second warning signal provides more stringent protection to ensure that the switching transistor 202 will not be damaged due to extreme conditions. Through the collaborative work of the charging regulation circuit 21, the first energy storage circuit 22, the voltage division regulation circuit 23, the second energy storage circuit 24, and the signal processing circuit 26, efficient, accurate monitoring and intelligent warning of the voltage stress of the switching transistor 202 are achieved.

[0073] In some other embodiments, the voltage stress detection circuit 20 specifically further includes a signal processing circuit 26, which is coupled after the second energy storage circuit 24 and connected to the main control circuit 201. The signal processing circuit 26 may specifically receive the second energy storage voltage of the second energy storage circuit 24, and calculate the first energy storage voltage using the second energy storage voltage, so as to compare the calculated first energy storage voltage with the preset threshold and generate a corresponding warning signal.

[0074] Specifically, the signal processing circuit 26 calculates the first energy storage voltage from the second energy storage voltage using a set function, compares the calculated first energy storage voltage with a third preset threshold, and obtains a third comparison result. Among them, if the signal processing circuit 26 detects that the calculated first energy storage voltage does not exceed the third preset threshold, it sends a voltage feedback signal to the main control circuit 201; and when it detects that the calculated first energy storage voltage exceeds the third preset threshold, it sends a third warning signal to the main control circuit 201.

[0075] When the main control circuit 201 receives the voltage feedback signal, it normally sends a drive control signal, that is, it does not change the current drive control signal sent to the switching transistor 202. And when it receives the third warning signal, it reduces the duty cycle or signal frequency of the drive control signal to reduce the voltage stress of the switching transistor 202; or immediately stops sending the drive control signal to prevent the switching transistor 202 from being damaged due to excessive voltage stress.

[0076] Similarly, by setting different preset thresholds, intelligent identification and response to voltage stress exceeding different levels are achieved, improving the safety of the system. The third warning signal allows the system to take mild protection measures in the early stage, while the fourth warning signal provides more stringent protection to ensure that the switching transistor 202 is not damaged under extreme conditions. And the calculated first energy storage voltage directly reflects the voltage stress of the switching transistor 202, so that detecting and recording the calculated first energy storage voltage can more intuitively reflect the change of the voltage stress of the switching transistor 202, and at the same time, a more stable and accurate voltage stress evaluation and feedback regulation can be realized by using the second energy storage circuit 24. Through the collaborative work of the charging regulation circuit 21, the first energy storage circuit 22, the voltage division regulation circuit 23, the second energy storage circuit 24 and the signal processing circuit 26, efficient and accurate monitoring and intelligent warning of the voltage stress of the switching transistor 202 are achieved.

[0077] In other embodiments, when the signal processing circuit 26 can specifically also compare the calculated first energy storage voltage with a fourth preset threshold to obtain a fourth comparison result. Among them, the fourth preset threshold is greater than the third preset threshold, so that when it detects that the calculated first energy storage voltage exceeds the fourth preset threshold, it sends a fourth warning signal to the main control circuit 201, so that the main control circuit 201 stops sending the drive control signal in response to the fourth warning signal. The present application does not limit this.

[0078] In some embodiments, the voltage stress detection circuit 20 specifically further includes a filtering circuit 25. The filtering circuit 25 is coupled after the second energy storage circuit 24 and connected to the main control circuit 201 to receive the second energy storage voltage of the second energy storage circuit 24 and perform filtering adjustment on it.

[0079] Specifically, the filtering circuit 25 filters the received second energy storage voltage to remove high-frequency noise and other unnecessary fluctuations, and then outputs it to the main control circuit 201 to ensure that the output voltage signal is smoother and more stable.

[0080] The main control circuit 201 can specifically also receive the second energy storage voltage after filtering and adjustment from the filtering circuit 25, and accordingly adjust the drive control signal sent to the switching transistor 202, thereby effectively improving the accuracy of voltage stress evaluation. The filtered voltage signal reduces false triggering caused by transient changes, making the system response more stable and reliable, and contributing to more precise drive control.

[0081] Please continue to refer to Figure 3 and Figure 4 , where Figure 3 is Figure 2 a schematic structural diagram of an embodiment of the switching regulation circuit in Figure 4 is Figure 3 a schematic waveform diagram of the switching voltage signals of each switching transistor in the switching regulation circuit in

[0082] It can be understood that the switching regulation circuit 200 may specifically include a transformer, a high-voltage part of a full-bridge structure located on the primary side of the transformer, that is, the high-voltage side HV, whose ground is HVGND, and a low-voltage part of a full-wave rectification structure located on the secondary side of the transformer, that is, the low-voltage side LV. The main control chip is located on the low-voltage side LV, whose ground is GND. And the switching regulation circuit 200 is only an example. In fact, it can include any fully controlled power device, and specifically can also be a totem pole conversion circuit, a boost conversion circuit, a buck conversion circuit, or any other reasonable signal function circuit integrated with power semiconductor devices. The present application does not make any limitations in this regard.

[0083] In this embodiment, the switching regulation circuit 200 specifically includes a first switching transistor Q1, a second switching transistor Q2, a third switching transistor Q3, a fourth switching transistor Q4, a fifth switching transistor Q5, a sixth switching transistor Q6, a transformer T, an output inductor L, an output capacitor C, and a main control circuit (not shown in the figure). The transformer T includes a coupled primary winding RZ1 and secondary winding RZ2.

[0084] Among them, the second terminal of the third switching transistor Q3 is coupled to the second terminal of the fifth switching transistor Q5 and is used to be coupled to the first terminal of a power supply circuit (not shown in the figure). The third terminal of the third switching transistor Q3 is coupled to the second terminal of the fourth switching transistor Q4 and the first terminal of the primary winding RZ1. The third terminal of the fifth switching transistor Q5 is coupled to the second terminal of the sixth switching transistor Q6 and the second terminal of the primary winding RZ1. The third terminal of the fourth switching transistor Q4 is coupled to the third terminal of the sixth switching transistor Q6 and the high-voltage side ground terminal HVGND and is used to be coupled to the second terminal of the power supply circuit. The first terminal of the secondary winding RZ2 is coupled to the second terminal of the second switching transistor Q2. The second terminal of the secondary winding RZ2 is coupled to the first terminal of the output inductor L. The second terminal of the output inductor L is coupled to the first terminal of the output capacitor C. The third terminal of the secondary winding RZ2 is coupled to the second terminal of the first switching transistor Q1. The third terminal of the first switching transistor Q1 is coupled to the third terminal of the second switching transistor Q2 and the second terminal of the output capacitor C and is grounded to GND. The first terminal of each of the first to sixth switching transistors Q1 to Q6 is coupled to the main control circuit 201.

[0085] It should be noted that as Figure 4 shown, in an ideal situation, when each switching transistor 202 is turned on, the charge regulation circuit 21 will detect a relatively low voltage difference (close to 0V); while when the switching transistor 202 is turned off, the charge regulation circuit 21 detects a relatively high voltage spike. However, in actual applications, when the first switching transistor Q1 and the second switching transistor Q2 are turned off, due to the existence of parasitic parameters of the power loop and the switching transistor 202 itself, an oscillating voltage spike greater than the steady-state voltage will be excited at both ends of the first switching transistor Q1 and the second switching transistor Q2.

[0086] Further, please refer to Figure 5 , Figure 5 which is a schematic structural diagram of the third embodiment of the voltage stress detection circuit of the present application. The difference between the voltage stress detection circuit in this embodiment and the second embodiment of the voltage stress detection circuit provided by the present application is that the charge regulation circuit 31 in the voltage stress detection circuit 30 includes a first diode D1 and a first resistor R1, the first energy storage circuit 32 includes a first capacitor C1, the voltage division regulation circuit 33 includes a second resistor R2, a third resistor R3, and a second diode D2, and the second energy storage circuit 34 includes a second capacitor C2.

[0087] Wherein, the first end of the first diode D1 is used to be coupled to the switching transistor 202, the second end of the first diode D1 is coupled to the first end of the first resistor R1, the second end of the first resistor R1 is coupled to the first end of the first capacitor C1 and the first end of the second resistor R2, the second end of the first capacitor C1 is coupled to the second end of the third resistor R3, the second end of the second capacitor C2 and grounded at GND, the second end of the second resistor R2 is coupled to the first end of the third resistor R3 and the first end of the second diode D2, and the second end of the second diode D2 is coupled to the first end of the second capacitor C2 and is used to be coupled to the main control circuit.

[0088] In some embodiments, the voltage stress detection circuit 30 further specifically includes a filtering circuit 35, and the filtering circuit 35 includes a fourth resistor R4, a third capacitor C3 and a fifth resistor R5; wherein, the first end of the fourth resistor R4 is coupled to the second end of the second diode D2 and the first end of the second capacitor C2, the second end of the fourth resistor R4 is coupled to the first end of the third capacitor C3, the first end of the fifth resistor R5 and is used to be coupled to the main control circuit, and the second end of the third capacitor C3 is coupled to the second end of the fifth resistor R5, the second end of the first capacitor C1, the second end of the third resistor R3, the second end of the second capacitor C2 and grounded at GND.

[0089] It can be understood that taking the switching transistor 202 to be detected in the switching regulation circuit 200 as the first switching transistor Q1, the first input terminal VH+ of the voltage stress detection circuit 30 is connected to the second terminal Vds1 of the first switching transistor Q1, the second input terminal VH- of the voltage stress detection circuit 30 is connected to the third terminal of the first switching transistor Q1, and the first output terminal VL+ and the second output terminal VL- of the voltage stress detection circuit 30 are connected to the main control circuit as an example. Then it can be known that the oscillating spike voltage between the second terminal Vds1 and the third terminal of the first switching transistor Q1 will charge the first capacitor C1 through the first diode D1 and the first resistor R1. Adjusting the resistance value of the first resistor R1 can adjust the charging speed of the first capacitor C1. On the premise of ensuring that the first diode D1 will not have overcurrent, the faster the charging speed, the better, so as to ensure that the voltage of the first capacitor C1 is closer to the voltage peak value of the real switching voltage signal.

[0090] Since the resistance values of the second resistor R2 and the third resistor R3 are relatively large, even after the first switching transistor Q1 is turned on and the switching voltage signal drops to 0, the first energy storage voltage of the first capacitor C1 can still be maintained until the next switching cycle. The first energy storage voltage of the first capacitor C1 is generally relatively high, above dozens of volts, while the voltage at the input port of the main control circuit needs to be lower than 3.3V or 5V.

[0091] Therefore, it is necessary to divide the voltage by the second resistor R2 and the third resistor R3 to reduce the voltage to below 3.3V or 5V, and then transfer it to the subsequent circuit. After the voltage is reduced to the low voltage of 3.3V or 5V, the second capacitor C2 will be charged through the second diode D2. The second energy storage voltage of the second capacitor C2 and the first energy storage voltage of the first capacitor C1 are in a linear function relationship. Finally, it passes through the fourth resistor R4, the third capacitor C3, and the fifth resistor R5 for filtering. After filtering out high-frequency interference, the voltage value is transmitted to the input port of the main control circuit. The main control circuit collects the voltage of the second capacitor C2, and through the linear function relationship with the first capacitor C1, the first energy storage voltage of the first capacitor C1 can be calculated. The first energy storage voltage of the first capacitor C1 is the voltage stress of the first switching tube Q1. When the voltage value calculated by the main control circuit exceeds the limit value of the first switching tube Q1, it can immediately respond and take measures such as wave blocking or power reduction to avoid further increase in the voltage stress of the first switching tube Q1.

[0092] It should be noted that when the switching tube 202 to be detected in the switching regulation circuit 200 is the second switching tube Q2, the first input terminal VH+ of the voltage stress detection circuit 30 can specifically be connected to the second terminal Vds2 of the second switching tube Q2, and the second input terminal VH- of the voltage stress detection circuit 30 is connected to the third terminal of the second switching tube Q2. The corresponding signal processing process is the same as above; and when the switching regulation circuit 200 is in other circuit forms, the signal processing process of the switching tube 202 located on the low voltage side LV is also the same as above, which will not be elaborated here.

[0093] In the above solution, by real-time monitoring of the voltage stress of the first switching tube Q1 and / or the second switching tube Q2, once the stress exceeds the limit value, the main control circuit immediately takes response measures to avoid continuous increase and damage of the stress of the first switching tube Q1 and / or the second switching tube Q2, thereby achieving the purpose of improving the product reliability.

[0094] Please refer to Figure 6 , Figure 6 FIG. is a schematic structural diagram of the fourth embodiment of the voltage stress detection circuit of the present application. The difference between the voltage stress detection circuit in this embodiment and the second embodiment of the voltage stress detection circuit provided by the present application is that the voltage stress detection circuit 40 specifically further includes an isolation circuit 47.

[0095] It can be understood that when the switching tube 202 to be detected in the switching regulation circuit 200 is located on the high voltage side HV, while the main control circuit 201 is located on the low voltage side LV, resulting in no common ground, it is necessary to introduce the isolation circuit 47.

[0096] Specifically, the isolation circuit 47 is coupled after the second energy storage circuit 44 and connected to the main control circuit 201. The isolation circuit 47 receives the second energy storage voltage of the second energy storage circuit 44, isolates and regulates it, and then outputs it to the main control circuit 201, ensuring complete electrical isolation between the main control circuit 201 and the high-voltage side HV, preventing any possible electric shock risk or interference, thus avoiding potential safety hazards and significantly improving the safety and reliability of the system; moreover, the isolated second energy storage voltage is transmitted to the main control circuit 201, which will provide a safe and reliable voltage stress reference signal for the main control circuit 201.

[0097] In some embodiments, the isolation circuit 47 may specifically include one or more of any reasonable circuit units with the function of isolating the high- and low-voltage sides LV, such as an optocoupler, a transformer isolation, a digital isolator, etc., to achieve electrical isolation without affecting signal transmission, and the present application does not make any limitations in this regard.

[0098] In some embodiments, the voltage stress detection circuit 40 further specifically includes a differential input isolation operational amplifier circuit 48. The differential input isolation operational amplifier circuit 48 is coupled to the isolation circuit 47, and the isolation circuit 47 is used to cooperate with the differential input isolation operational amplifier circuit 48 to isolate and regulate the second energy storage voltage, which can effectively improve the anti-interference ability of the signal and ensure that the second energy storage voltage is accurately isolated and regulated before being transmitted to the main control circuit 201, so as to further improve the signal processing ability and reliability of the system.

[0099] It can be understood that the charging regulation circuit 41, the first energy storage circuit 42, the voltage division regulation circuit 43, the second energy storage circuit 44, and the filtering circuit 45 in this embodiment are the same as the charging regulation circuit 21, the first energy storage circuit 22, the voltage division regulation circuit 23, the second energy storage circuit 24, and the filtering circuit 25 respectively. For details, please refer to Figure 2 and the relevant text content, which will not be elaborated here.

[0100] Please refer to Figure 7 , Figure 7 is a schematic structural diagram of the fifth embodiment of the voltage stress detection circuit of the present application. The difference between the voltage stress detection circuit in this embodiment and the third embodiment of the voltage stress detection circuit provided by the present application is that the voltage stress detection circuit 50 further specifically includes an isolation circuit 57.

[0101] It can be understood that as Figure 3As shown, taking the switching transistor 202 to be detected in the switching regulation circuit 200 as the fourth switching transistor Q4 or the sixth switching transistor Q6, and taking the first input terminal VH+ of the voltage stress detection circuit 50 as connected to the second terminal of the fourth switching transistor Q4 or the sixth switching transistor Q6, and the second input terminal VH- of the voltage stress detection circuit 50 as connected to the high-voltage side ground terminal HVGND as an example, it can be known that since the fourth switching transistor Q4 and the sixth switching transistor Q6 are located on the high-voltage side HV of the switching regulation circuit 200, while the main control circuit 201 is located on the low-voltage side LV, they cannot share a common ground. Therefore, an isolation circuit 57 needs to be provided to electrically isolate the voltage stress detection circuit 50 from the main control circuit 201.

[0102] The main control circuit 201 includes a digital signal processing circuit DSP; the first terminal of the isolation circuit 57 is coupled to the first level supply terminal HV-VCC, the second terminal of the isolation circuit 57 is coupled to the second level supply terminal VCC, the third terminal in+ of the isolation circuit 57 is coupled to the second terminal of the fourth resistor R4, the first terminal of the third capacitor C3, and the first terminal of the fifth resistor R5, the fourth terminal in- of the isolation circuit 57 is coupled to the second input terminal VH-, the second terminal of the first capacitor C1, the second terminal of the third resistor R3, the second terminal of the second capacitor C2, the second terminal of the third capacitor C3, and the second terminal of the fifth resistor R5, the fifth terminal of the isolation circuit 57 is coupled to the high-voltage side ground terminal HVGND, the sixth terminal out of the isolation circuit 57 is coupled to the digital signal processing circuit DSP of the main control circuit 201, and the seventh terminal of the isolation circuit 57 is coupled to the ground terminal GND.

[0103] Among them, the processing process of the voltage stress detection circuit 50 for the switching voltage signal of the fourth switching transistor Q4 or the sixth switching transistor Q6 in this embodiment is different from Figure 5 the processing process of the voltage stress detection circuit 30 for the switching voltage signal of the first switching transistor Q1 or the second switching transistor Q2 in that after obtaining the second energy storage voltage after filtering processing, it is further isolated and regulated by the isolation circuit 57 and then output to the digital signal processing circuit DSP of the main control circuit 201. For details, please refer to Figure 5 and the relevant text content, which will not be elaborated here.

[0104] Further, in some embodiments, when the switch tube 202 to be detected in the switch adjustment circuit 200 is the third switch tube Q3 or the fifth switch tube Q5, and the first input terminal VH+ of the voltage stress detection circuit 50 is connected to the second end of the third switch tube Q3 or the fifth switch tube Q5, and the second input terminal VH- of the voltage stress detection circuit 50 is connected to the third end of the third switch tube Q3 or the fifth switch tube Q5, the voltage stress detection circuit 50 may specifically further include a differential input isolation operational amplifier circuit 58, and the differential input isolation operational amplifier circuit 58 is coupled to the isolation circuit 57 to cooperate with each other to isolate and adjust the filtered second energy storage voltage and then output it to the digital signal processing circuit DSP of the main control circuit 201.

[0105] It can be understood that the charging adjustment circuit 51, the first energy storage circuit 52, the voltage division adjustment circuit 53, the second energy storage circuit 54, and the filtering circuit 55 in this embodiment are the same as the charging adjustment circuit 31, the first energy storage circuit 32, the voltage division adjustment circuit 33, the second energy storage circuit 34, and the filtering circuit 35 respectively. For details, please refer to Figure 5 and the relevant text content, which will not be repeated here.

[0106] Please refer to Figure 8 , Figure 8 is a schematic structural diagram of the sixth embodiment of the voltage stress detection circuit of the present application. The difference between the voltage stress detection circuit in this embodiment and the fourth embodiment of the voltage stress detection circuit provided by the present application is that the voltage stress detection circuit 60 specifically further includes a gating circuit 69.

[0107] It can be understood that the number of switch tubes 202 to be detected in the switch adjustment circuit 200 is at least two. In order to save circuit resources as much as possible and effectively detect the voltage stress of each switch tube 202, it is necessary to introduce a gating circuit 69 to realize the orderly switching between multiple switch tubes 202 and the charging adjustment circuit 61, ensuring that each switch tube 202 can obtain effective voltage stress monitoring under its corresponding charging adjustment circuit 61; and the switching frequency of the gating circuit 69 needs to be as close as possible to the switching frequency of each switch tube 202 to avoid untimely monitoring and feedback adjustment.

[0108] Specifically, the number of the switch tubes 202 and the charging adjustment circuit 61 is equal and at least two. The gating circuit 69 is coupled to each charging adjustment circuit 61 and is used to be coupled to each switch tube 202, and each switch tube 202 is cyclically and alternately coupled to its corresponding charging adjustment circuit 61 at intervals of a set time period.

[0109] It is understandable that the gating circuit 69 can specifically connect each switching transistor 202 to its corresponding charge regulation circuit 61 in sequence at a preset time interval (such as millisecond level or shorter), and in a cyclic and alternating manner, to ensure that each switching transistor 202 can obtain effective voltage stress monitoring under its corresponding charge regulation circuit 61. Thus, it can be seen that the gating circuit 69 enables multiple switching transistors 202 and charge regulation circuits 61 to work alternately, ensuring that each switching transistor 202 can obtain sufficient voltage stress monitoring.

[0110] In some embodiments, the gating circuit 69 can specifically include one or more of any reasonable elements with gating functions such as relays, switching transistors, timers, multiplexers, etc., and the present application does not limit this.

[0111] Among them, taking the gating circuit 69 including at least two relays as an example, each relay further includes a controlled coil and a normally open contact. Each controlled coil is coupled to the main control circuit 201, and each normally open contact is coupled between each switching transistor 202 and its corresponding charge regulation circuit 61, so that when each controlled coil receives the trigger signal sent by the main control circuit 201 in sequence at intervals of a set duration in a cyclic and alternating manner, each normally open contact can be orderly turned on and switched, so that each switching transistor 202 is coupled to its corresponding charge regulation circuit 61 in sequence in a cyclic and alternating manner, ensuring that each switching transistor 202 can obtain effective voltage stress monitoring under its corresponding charge regulation circuit 61.

[0112] It is understandable that the first energy storage circuit 62, voltage division and regulation circuit 63, second energy storage circuit 64, filtering circuit 65, isolation circuit 67, and differential input isolation operational amplifier circuit 68 in this embodiment are the same as the first energy storage circuit 42, voltage division and regulation circuit 43, second energy storage circuit 44, filtering circuit 45, isolation circuit 47, and differential input isolation operational amplifier circuit 48 respectively. For details, please refer to Figure 6 and the relevant text content, which will not be elaborated here.

[0113] Please refer to Figure 9 , Figure 9 is a schematic structural diagram of the seventh embodiment of the voltage stress detection circuit of the present application. The difference between the voltage stress detection circuit in this embodiment and the fifth embodiment of the voltage stress detection circuit provided by the present application is that the voltage stress detection circuit 70 specifically further includes a gating circuit 79.

[0114] For easy understanding, as Figure 3As shown, taking the gating circuit 79 including a first relay and a second relay as an example, the first relay includes a first controlled coil and a first normally open contact K1 which are coupled, and the second relay includes a second controlled coil and a second normally open contact K2 which are coupled. The first controlled coil and the second controlled coil are coupled to the main control circuit 201. The first normally open contact K1 is coupled between the third switching transistor Q3 and one of the first diodes D1, and the second normally open contact K2 is coupled between the fifth switching transistor Q5 and the other first diode D1. When the main control circuit 201 alternately sends trigger signals to the first controlled coil and the second controlled coil in sequence, the first normally open contact K1 and the second normally open contact K2 can be orderly turned on and switched, so that the third switching transistor Q3 and the fifth switching transistor Q5 are alternately coupled to their corresponding charge regulation circuits 71 in sequence, ensuring that both the third switching transistor Q3 and the fifth switching transistor Q5 can obtain effective voltage stress monitoring under their corresponding charge regulation circuits 71. For the corresponding signal processing process, please refer to Figure 8 and the relevant text content, which will not be elaborated here.

[0115] In other embodiments, when the switching transistors 202 to be detected in the switching regulation circuit 200 are the fourth switching transistor Q4 and the sixth switching transistor Q6, the voltage stress detection circuit 70 can specifically further remove the differential input isolation operational amplifier circuit 78. When the switching transistors 202 to be detected in the switching regulation circuit 200 are the first switching transistor Q1 and the second switching transistor Q2, the voltage stress detection circuit 70 can specifically further remove the isolation circuit 57. When the switching transistors 202 to be detected in the switching regulation circuit 200 are any number of the first to sixth switching transistors Q6, the gating circuit 79 can specifically further include any number of relays such as 1, 2, 3, or 6, which is the same as the number of the switching transistors 202 to be detected. And the voltage stress detection circuit 70 needs to include the isolation circuit 57 and the differential input isolation operational amplifier circuit 78. The present application does not make any limitation in this regard.

[0116] In some other embodiments, when there are at least two switching transistors 202 to be detected in the switching regulation circuit 200 and they are both on the high voltage side HV or the low voltage side LV, the gating circuit 79 can specifically be removed. However, in this case, the detected value is the maximum value of the voltage stresses of at least two switching transistors 202. That is, when the main control circuit 201 detects that the voltage stress exceeds the set voltage threshold, the switching states of at least two switching transistors 202 to be detected are specifically adjusted synchronously. The present application does not make any limitation in this regard.

[0117] It is understandable that the first energy storage circuit 72, voltage division and regulation circuit 73, second energy storage circuit 74, filtering circuit 75, isolation circuit 77, and differential input isolation operational amplifier circuit 78 in this embodiment are the same as the first energy storage circuit 52, voltage division and regulation circuit 53, second energy storage circuit 54, filtering circuit 55, isolation circuit 57, and differential input isolation operational amplifier circuit 58 respectively. For details, please refer to Figure 7 and the relevant text content, which will not be elaborated here.

[0118] This application specifically also adopts a voltage stress detection method. Please refer to Figure 10 , Figure 10 which is a schematic flowchart of the first embodiment of the voltage stress detection method of this application. Specifically, it may include the following steps:

[0119] S81: Obtain the switching voltage signal of the switching tube.

[0120] It is understandable that the voltage stress detection method in this embodiment is specifically a method in which the voltage stress detection circuit monitors the switching voltage signal of the switching tube in the switching regulation circuit in real time, and performs feedback regulation on the switching tube in response to possible abnormal voltage stress, so as to effectively avoid excessive power consumption of the switching tube, affecting its lifespan, or even irreversible failure and burnout. Among them, the switching regulation circuit includes a main control circuit and a switching tube controlled by the main control circuit; the voltage stress detection circuit includes a charging regulation circuit and a first energy storage circuit. The charging regulation circuit is used to be coupled to the switching tube, and the first energy storage circuit is coupled to the charging regulation circuit and is used to be coupled to the main control circuit.

[0121] It is worth noting that when the first end of the switching tube is the control end and the first end of the switching tube receives the drive control signal sent by the main control circuit, it can be triggered to conduct or turn off its second end and third end in response to the drive control signal.

[0122] Specifically, the charging regulation circuit obtains the switching voltage signals of the second end and the third end of the switching tube.

[0123] S82: Obtain the first energy storage voltage using the switching voltage signal.

[0124] The first energy storage circuit is used to store the electrical energy from the charging regulation circuit and convert it into the first energy storage voltage that can be read by the main control circuit.

[0125] S83: Output the first energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the first energy storage voltage.

[0126] It is understandable that the charging regulation circuit is used to obtain the switching voltage signal of the switching transistor and start charging the first energy storage circuit using this switching voltage signal. The first energy storage circuit gradually accumulates energy, and its voltage level, that is, the first energy storage voltage, reflects the maximum voltage stress in the most recent switching event.

[0127] The main control circuit detects and reads the first energy storage voltage, evaluates the working state of the current switching transistor based on this, and determines whether it is necessary to adjust the drive control signal sent to the switching transistor according to a preset safety threshold.

[0128] Among them, if the main control circuit detects that the first energy storage voltage exceeds the set safety range, it indicates that the switching transistor has suffered excessive voltage stress. The main control circuit can take measures to reduce the load, power, slow down the switching speed or temporarily stop the switching operation, such as reducing the duty cycle and / or signal frequency of the drive control signal sent to the switching transistor, or directly blocking the drive control signal, that is, not sending the drive control signal to the switching transistor, to protect the switching transistor from damage. On the contrary, if it is detected that the first energy storage voltage is within the safety range, the main control circuit can maintain the normal drive control strategy.

[0129] From this, it can be seen that this voltage stress detection circuit can effectively monitor and record the voltage stress situation of the corresponding switching transistor, and quickly feedback it to the main control circuit, realizing real-time monitoring of the voltage stress. And by accurately measuring the transient voltage change across the switching transistor, the accuracy of the voltage stress evaluation is ensured. The entire detection process does not interfere with the normal operation of the original switching regulation circuit, avoiding additional introduced noise or errors. The main control circuit can flexibly adjust the drive control strategy according to actual needs, improving the adaptability and reliability of the system. Compared with complex external monitoring devices, this built-in voltage stress detection scheme has a simple structure and is easy to integrate, reducing the overall system cost. Application scenarios This voltage stress detection circuit is particularly suitable for various switching regulation circuits, especially those application occasions with strict requirements for power semiconductor devices, such as motor drivers, on-board chargers, DC-DC (Direct Current) converters, etc. in new energy vehicles. By introducing such a circuit, not only can the power device be effectively prevented from failing due to excessive voltage stress, but also valuable data support can be provided for subsequent product reliability analysis. In short, this voltage stress detection circuit realizes efficient and accurate monitoring of the voltage stress of the switching transistor through the cooperation of the charging regulation circuit and the first energy storage circuit. It not only helps to improve the overall performance and reliability of the switching regulation circuit, but also provides a solid foundation for future intelligent control and fault diagnosis.

[0130] Please refer to Figure 11 , Figure 11It is a schematic flowchart of the second embodiment of the voltage stress detection method of the present application. The voltage stress detection method of this embodiment is Figure 10 a schematic flowchart of a refined embodiment of the voltage stress detection method in

[0131] S91: Obtain the switching voltage signal of the switching tube.

[0132] S92: Obtain the first energy storage voltage using the switching voltage signal.

[0133] Among them, S91 and S92 are the same as Figure 10 S81 and S82 in

[0134] For details, please refer to S81 and S82 and their related text descriptions, which will not be elaborated here.

[0135] Specifically, the voltage stress detection circuit further includes a voltage division and regulation circuit and a second energy storage circuit. The voltage division and regulation circuit is coupled between the first energy storage circuit and the second energy storage circuit. The second energy storage circuit is coupled after the voltage division and regulation circuit and is connected to the main control circuit.

[0136] Among them, the voltage division and regulation circuit is used to receive the first energy storage voltage of the first energy storage circuit and perform voltage division and regulation on it. Specifically, it can reduce the amplitude of the first energy storage voltage according to a preset ratio or dynamic adjustment strategy to ensure that the voltage transmitted to the main control circuit is within a safe range and avoid damage to the main control circuit caused by excessive voltage.

[0137] S94: Obtain the second energy storage voltage using the first energy storage voltage after voltage division and regulation.

[0138] The second energy storage circuit receives and stores the first energy storage voltage after voltage division and regulation and gradually accumulates energy. Its voltage level, that is, the second energy storage voltage, reflects the voltage stress condition of the switching tube.

[0139] S95: Output the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the second energy storage voltage.

[0140] The main control circuit detects and reads the second energy storage voltage and evaluates the current working state of the switching tube based on this, so as to judge whether it is necessary to adjust the drive control signal sent to the switching tube according to a preset safety threshold.

[0141] Among them, if the main control circuit detects that the second energy storage voltage exceeds the set safety range, it indicates that the switching transistor has suffered excessive voltage stress. The main control circuit can take measures to reduce the load, slow down the switching speed, or temporarily stop the switching operation to protect the switching transistor from damage. Conversely, if it is detected that the second energy storage voltage is within the safety range, the main control circuit can maintain the normal drive control strategy.

[0142] Please refer to Figure 12 , Figure 12 which is a schematic flowchart of the third embodiment of the voltage stress detection method of the present application. The voltage stress detection method of this embodiment is Figure 11 a schematic flowchart of a refined embodiment of the voltage stress detection method in

[0143] S101: Obtain the switching voltage signal of the switching transistor.

[0144] S102: Obtain the first energy storage voltage using the switching voltage signal.

[0145] S103: Perform voltage division adjustment on the first energy storage voltage.

[0146] S104: Obtain the second energy storage voltage using the first energy storage voltage after voltage division adjustment.

[0147] Among them, S101, S102, S103, and S104 are the same as Figure 11 S91, S92, S93, and S94 in

[0148] S105: Detect whether the second energy storage voltage is greater than the first preset threshold.

[0149] Specifically, the voltage stress detection circuit further includes a signal processing circuit, which is coupled after the second energy storage circuit and connected to the main control circuit.

[0150] The signal processing circuit is used to receive the second energy storage voltage of the second energy storage circuit and compare it with the first preset threshold to determine whether the second energy storage voltage is greater than the first preset threshold.

[0151] Among them, if the second energy storage voltage is greater than the first preset threshold, execute S106; if the second energy storage voltage is not greater than the first preset threshold, return to execute S101.

[0152] S106: Detect whether the second energy storage voltage is greater than the second preset threshold.

[0153] Specifically, the signal processing circuit further compares the second energy storage voltage with a second preset threshold to determine whether the second energy storage voltage is greater than the second preset threshold.

[0154] Wherein, if the second energy storage voltage is greater than the second preset threshold, S108 is executed; if the second energy storage voltage is not greater than the first preset threshold, return to execute S107.

[0155] S107: Send a first warning signal to the main control circuit so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the first warning signal.

[0156] When the signal processing circuit detects that the second energy storage voltage exceeds the first preset threshold but does not exceed the second preset threshold, it sends a first warning signal to the main control circuit.

[0157] After receiving the first warning signal, the main control circuit takes preventive measures, such as reducing the duty cycle of the drive control signal or lowering the signal frequency, to reduce the voltage stress on the switching transistor.

[0158] S108: Send a second warning signal to the main control circuit so that the main control circuit stops sending the drive control signal in response to the second warning signal.

[0159] When the signal processing circuit detects that the second energy storage voltage exceeds the second preset threshold, it sends a second warning signal to the main control circuit.

[0160] After receiving the second warning signal, the main control circuit immediately stops sending the drive control signal to prevent the switching transistor from being damaged due to excessive voltage stress.

[0161] Specifically, in some other embodiments, specifically between S106 and S101, it further includes: sending a voltage feedback signal to the main control circuit based on the currently obtained second energy storage voltage, so that the main control circuit normally sends the drive control signal, that is, does not change the current drive control signal sent to the switching transistor, and records the voltage feedback signal for subsequent analysis and statistics.

[0162] Please refer to Figure 13 , Figure 13 is a schematic flowchart of the fourth embodiment of the voltage stress detection method of the present application. The voltage stress detection method of this embodiment is Figure 11 a schematic flowchart of a refined embodiment of the voltage stress detection method in

[0163] S111: Obtain the switching voltage signal of the switching transistor.

[0164] S112: Obtain the first energy storage voltage using the switching voltage signal.

[0165] S113: Divide and regulate the first energy storage voltage.

[0166] S114: Obtain the second energy storage voltage using the divided and regulated first energy storage voltage.

[0167] Among them, S111, S112, S113, and S114 are the same as Figure 11 S91, S92, S93, and S94 in, for specific details, please refer to S91, S92, S93, and S94 and their related textual descriptions, which will not be elaborated here.

[0168] S115: Calculate the first energy storage voltage using the set function for the second energy storage voltage.

[0169] Specifically, the voltage stress detection circuit further includes a signal processing circuit, which is coupled after the second energy storage circuit and connected to the main control circuit.

[0170] The signal processing circuit can specifically also receive the second energy storage voltage of the second energy storage circuit and calculate the first energy storage voltage using the second energy storage voltage.

[0171] S116: Detect whether the calculated first energy storage voltage is greater than the third preset threshold.

[0172] The signal processing circuit compares the calculated first energy storage voltage with the third preset threshold to determine whether the calculated first energy storage voltage is greater than the third preset threshold.

[0173] Among them, if the calculated first energy storage voltage is greater than the third preset threshold, then execute S117; if the calculated first energy storage voltage is not greater than the third preset threshold, then return to execute S111.

[0174] S117: Send a third warning signal to the main control circuit so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the third warning signal, or stops sending the drive control signal.

[0175] Specifically, when the signal processing circuit detects that the calculated first energy storage voltage exceeds the third preset threshold, it sends a third warning signal to the main control circuit.

[0176] When the main control circuit receives the third warning signal, it reduces the duty cycle or signal frequency of the drive control signal to reduce the voltage stress of the switching tube; or immediately stops sending the drive control signal to prevent the switching tube from being damaged due to excessive voltage stress.

[0177] Specifically, in some other embodiments, between the above S116 and S111, it further specifically includes: based on the currently obtained second energy storage voltage, sending a voltage feedback signal to the main control circuit to enable the main control circuit to normally send a drive control signal, that is, without changing the current drive control signal sent to the switching tube, and recording the voltage feedback signal for subsequent analysis and statistics.

[0178] It can be understood that, in some other embodiments, the voltage stress detection circuit specifically further includes some other more specific circuit units to be able to correspondingly implement other more specific voltage stress detection methods. For details, please refer to Figures 1 - 9 and the relevant textual descriptions, which will not be elaborated herein.

[0179] This application specifically also adopts a power conversion circuit. Please refer to Figure 14 , Figure 14 which is a schematic structural diagram of an embodiment of the power conversion circuit of this application. In this embodiment, the power conversion circuit 120 includes a switch regulation circuit 121 and a voltage stress detection circuit 122 that are coupled to each other.

[0180] It should be noted that the voltage stress detection circuit 122 described in this embodiment is the voltage stress detection circuit 10, voltage stress detection circuit 20, voltage stress detection circuit 30, voltage stress detection circuit 40, voltage stress detection circuit 50, voltage stress detection circuit 60, or voltage stress detection circuit 70 described in any of the above embodiments. For details, please refer to Figures 1 - 9 and the relevant textual content, which will not be elaborated herein.

[0181] This application specifically also adopts an electronic device. Please refer to Figure 15 , Figure 15 which is a schematic structural diagram of an embodiment of the electronic device of this application. In this embodiment, the electronic device 130 includes a housing 131 and a signal function circuit 132 connected to the housing 131.

[0182] It should be noted that the signal function circuit 132 described in this embodiment is the voltage stress detection circuit 10, voltage stress detection circuit 20, voltage stress detection circuit 30, voltage stress detection circuit 40, voltage stress detection circuit 50, voltage stress detection circuit 60, or voltage stress detection circuit 70 described in any of the above embodiments, or the power conversion circuit 120. For details, please refer to Figures 1 - 9 , Figure 14 and the relevant textual content, which will not be elaborated herein.

[0183] The beneficial effects of the present application are as follows: Different from the prior art, the charging regulation circuit in the voltage stress detection circuit provided by the present application is used to be coupled with the switching tube in the switching regulation circuit, and the first energy storage circuit is coupled to the charging regulation circuit and is used to be coupled with the main control circuit in the switching regulation circuit; wherein, the charging regulation circuit is configured to obtain the switching voltage signal of the switching tube and use the switching voltage signal to store energy in the first energy storage circuit; the first energy storage circuit is configured to output its current first energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the first energy storage voltage, thereby being able to effectively monitor the voltage stress of the switching tube in the switching regulation circuit in real time, and when it is detected that the voltage stress is abnormal, it is also possible to avoid excessive power consumption of the switching tube, affecting its lifespan, and even irreversible failure and burnout by timely adjusting the drive control signal sent to the switching tube, thus effectively avoiding voltage stress exceeding the standard, and being able to record this event when the voltage stress is too high, which is also very helpful for product reliability analysis and improvement; and whether the switching regulation circuit is in a known working condition, or the circuit parameters are abnormal or in other unknown working conditions, it is possible to effectively monitor whether the voltage stress is abnormal and take effective measures, which is helpful for improving product quality and improving the product design scheme.

[0184] The above is only the implementation mode of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A voltage stress detection circuit is applied to the voltage stress detection of a switching regulation circuit. The switching regulation circuit includes a main control circuit and a switching transistor controlled by the main control circuit, and is characterized in that The voltage stress detection circuit includes: A charging regulation circuit, which is used to be coupled with the switching transistor; A first energy storage circuit, which is coupled to the charging regulation circuit and is used to be coupled with the main control circuit; A voltage division regulation circuit and a second energy storage circuit, the voltage division regulation circuit is coupled to the first energy storage circuit and the second energy storage circuit, and the second energy storage circuit is used to be coupled with the main control circuit; Wherein, the charging regulation circuit is configured to obtain the switching voltage signal of the switching transistor and use the switching voltage signal to store energy in the first energy storage circuit; The voltage division regulation circuit is configured to receive the first energy storage voltage of the first energy storage circuit, perform voltage division regulation on the first energy storage voltage, and use the voltage division regulated first energy storage voltage to store energy in the second energy storage circuit; The second energy storage circuit is configured to output its current second energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal of the switching transistor in response to the second energy storage voltage.

2. The voltage stress detection circuit according to claim 1, wherein The voltage stress detection circuit further includes a signal processing circuit, the signal processing circuit is coupled to the second energy storage circuit and is used to be coupled with the main control circuit; Wherein, the signal processing circuit is configured to receive the second energy storage voltage of the second energy storage circuit, compare the second energy storage voltage with a first preset threshold and a second preset threshold respectively to obtain a first comparison result and a second comparison result, and send a first warning signal or a second warning signal to the main control circuit correspondingly in response to the first comparison result and the second comparison result, so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the first warning signal, or stops sending the drive control signal in response to the second warning signal; wherein, the first preset threshold is less than the second preset threshold.

3. The voltage stress detection circuit according to claim 1, wherein The voltage stress detection circuit further includes a signal processing circuit, the signal processing circuit is coupled to the second energy storage circuit and is used to be coupled with the main control circuit; Wherein, the signal processing circuit is configured to receive the second energy storage voltage of the second energy storage circuit, calculate the first energy storage voltage by using a set function for the second energy storage voltage, compare the calculated first energy storage voltage with a third preset threshold to obtain a third comparison result, and send a voltage feedback signal or a third warning signal to the main control circuit correspondingly in response to the third comparison result, so that the main control circuit normally sends the drive control signal in response to the voltage feedback signal, or reduces the duty cycle or signal frequency of the drive control signal, or stops sending the drive control signal in response to the third warning signal.

4. The voltage stress detection circuit according to claim 1, wherein The voltage stress detection circuit further includes a filtering circuit, the filtering circuit is coupled to the second energy storage circuit and is used to be coupled with the main control circuit; The filtering circuit is configured to receive the second energy storage voltage of the second energy storage circuit, and after filtering and regulating the second energy storage voltage, output it to the main control circuit, so that the main control circuit adjusts the drive control signal in response to the filtered and regulated second energy storage voltage.

5. The voltage stress detection circuit according to claim 1, wherein the voltage stress detection circuit further includes an isolation circuit, the isolation circuit is coupled to the second energy storage circuit, and is used to be coupled to the main control circuit; the isolation circuit is configured to receive the second energy storage voltage of the second energy storage circuit, and after isolating and regulating the second energy storage voltage, output it to the main control circuit, so that the main control circuit adjusts the drive control signal in response to the isolated and regulated second energy storage voltage.

6. The voltage stress detection circuit according to claim 5, wherein the voltage stress detection circuit further includes a differential input isolation operational amplifier circuit, the differential input isolation operational amplifier circuit is coupled to the isolation circuit, and the isolation circuit is used to cooperate with the differential input isolation operational amplifier circuit to isolate and regulate the second energy storage voltage.

7. The voltage stress detection circuit according to claim 1, wherein the charging regulation circuit includes a first diode and a first resistor, the first energy storage circuit includes a first capacitor, the voltage division regulation circuit includes a second resistor, a third resistor and a second diode, and the second energy storage circuit includes a second capacitor; wherein, the first end of the first diode is used to be coupled to the switching transistor, the second end of the first diode is coupled to the first end of the first resistor, the second end of the first resistor is coupled to the first end of the first capacitor and the first end of the second resistor, the second end of the first capacitor is coupled to the second end of the third resistor, the second end of the second capacitor and grounded, the second end of the second resistor is coupled to the first end of the third resistor and the first end of the second diode, and the second end of the second diode is coupled to the first end of the second capacitor and is used to be coupled to the main control circuit.

8. The voltage stress detection circuit according to any one of claims 1-7, wherein the voltage stress detection circuit further includes a gating circuit, the number of the switching transistors is equal to the number of the charging regulation circuits and is at least two, the gating circuit is coupled to each charging regulation circuit and is used to be coupled to each switching transistor, so as to sequentially and alternately couple each switching transistor to its corresponding charging regulation circuit at intervals of a set time duration.

9. A voltage stress detection method, characterized in that The voltage stress detection method includes: acquiring the switching voltage signal of the switching transistor; obtaining the first energy storage voltage by using the switching voltage signal; performing voltage division regulation on the first energy storage voltage; obtaining the second energy storage voltage by using the voltage division regulated first energy storage voltage; outputting the second energy storage voltage to the main control circuit, so that the main control circuit adjusts the drive control signal sent to the switching transistor in response to the second energy storage voltage.

10. The voltage stress detection method according to claim 9, wherein After the step of obtaining the second energy storage voltage by using the first energy storage voltage after voltage division regulation, and before the step of outputting the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the second energy storage voltage, the method further includes: Detecting whether the second energy storage voltage is greater than a first preset threshold; If the second energy storage voltage is greater than the first preset threshold, detecting whether the second energy storage voltage is greater than a second preset threshold; The step of outputting the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the second energy storage voltage includes: If the second energy storage voltage is not greater than the second preset threshold, sending a first warning signal to the main control circuit so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal in response to the first warning signal; If the second energy storage voltage is greater than the second preset threshold, sending a second warning signal to the main control circuit so that the main control circuit stops sending the drive control signal in response to the second warning signal.

11. The voltage stress detection method according to claim 9, wherein After the step of obtaining the second energy storage voltage by using the first energy storage voltage after voltage division regulation, and before the step of outputting the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the second energy storage voltage, the method further includes: Calculating the first energy storage voltage by using a set function for the second energy storage voltage; Detecting whether the calculated first energy storage voltage is greater than a third preset threshold; The step of outputting the second energy storage voltage to the main control circuit so that the main control circuit adjusts the drive control signal sent to the switching tube in response to the second energy storage voltage includes: If the calculated first energy storage voltage is greater than the third preset threshold, sending a third warning signal to the main control circuit so that the main control circuit reduces the duty cycle or signal frequency of the drive control signal, or stops sending the drive control signal, in response to the third warning signal.

12. An electric energy conversion circuit, characterized in that, The power conversion circuit includes a switch regulation circuit and a voltage stress detection circuit that are coupled to each other; Wherein, the voltage stress detection circuit is the voltage stress detection circuit according to any one of claims 1-8.

13. An electronic device, characterized in that, The electronic device includes a housing and a signal function circuit connected to the housing; Wherein, the signal function circuit is the voltage stress detection circuit according to any one of claims 1-8, or the power conversion circuit according to claim 12.

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