Power MOSFET gate oxide aging state evaluation device and method and medium

Abstract

The invention discloses a power MOSFET gate oxide aging state evaluation device and method and a medium, and relates to the technical field of power MOSFET device state evaluation, and the method comprises the steps: collecting a drain-source voltage and a drain current in a power MOSFET opening process in real time through a voltage detection module and a current detection module; determining the turn-on time in the turn-on process of the power MOSFET by using a turn-on time detection module; utilizing a turn-on energy loss calculation module to calculate turn-on energy loss according to the drain-source voltage, the drain current and the turn-on time; and utilizing a gate oxide aging state evaluation module to evaluate the gate oxide aging state of the power MOSFET according to the drain-source voltage, the drain current and the turn-on energy loss. According to the invention, the gate-oxide aging state of the power MOSFET is evaluated based on the turn-on energy loss of the power MOSFET, and the evaluation accuracy is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power MOSFET device state evaluation, and particularly to a device, method and medium for evaluating the aging state of the gate oxide of a power MOSFET. Background Art

[0002] Si power MOSFETs are widely used in industrial frequency converters, new energy vehicles, renewable energy systems, consumer electronics and other fields due to their advantages such as high switching speed, low on-resistance and high efficiency. However, during long-term operation, the gate oxide layer of the device will gradually age due to the electrothermal stress during high-frequency switching processes, resulting in problems such as threshold voltage drift, increased on-resistance, and increased switching losses, which in turn affect the system performance and stability. Traditional aging detection methods usually rely on offline testing or destructive analysis, which are not only complex to operate but also unable to achieve real-time monitoring, making it difficult to meet the requirements of modern power electronic systems for high reliability and efficient maintenance. Summary of the Invention

[0003] The purpose of the present application is to provide a device, method and medium for evaluating the aging state of the gate oxide of a power MOSFET, which evaluates the aging state of the gate oxide based on the turn-on energy loss of the power MOSFET, improving the accuracy of the evaluation.

[0004] To achieve the above purpose, the present application provides the following solutions:

[0005] In a first aspect, the present application provides a device for evaluating the aging state of the gate oxide of a power MOSFET, including:

[0006] A voltage detection module for real-time acquisition of the drain-source voltage during the turn-on process of the power MOSFET;

[0007] A current detection module for real-time acquisition of the drain current during the turn-on process of the power MOSFET;

[0008] A turn-on time detection module for determining the turn-on time during the turn-on process of the power MOSFET;

[0009] A turn-on energy loss calculation module connected to the voltage detection module, the current detection module and the turn-on time detection module for calculating the turn-on energy loss according to the drain-source voltage, the drain current and the turn-on time;

[0010] A gate oxide aging state evaluation module connected to the voltage detection module, the current detection module and the turn-on energy loss calculation module for evaluating the aging state of the gate oxide of the power MOSFET according to the drain-source voltage, the drain current and the turn-on energy loss.

[0011] Second aspect, the present application provides a method for evaluating the aging state of the gate oxide of a power MOSFET, including:

[0012] Obtain the drain-source voltage during the turn-on process of the power MOSFET;

[0013] Obtain the drain current during the turn-on process of the power MOSFET;

[0014] Determine the turn-on time during the turn-on process of the power MOSFET;

[0015] Calculate the turn-on energy loss according to the drain-source voltage, drain current, and turn-on time;

[0016] Evaluate the aging state of the gate oxide of the power MOSFET according to the drain-source voltage, drain current, and turn-on energy loss.

[0017] Third aspect, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the above method for evaluating the aging state of the gate oxide of a power MOSFET is implemented.

[0018] According to the specific embodiments provided by the present application, the following technical effects are disclosed:

[0019] The present application provides a device, method, and medium for evaluating the aging state of the gate oxide of a power MOSFET. The drain-source voltage and drain current during the turn-on process of the power MOSFET are collected in real time by using a voltage detection module and a current detection module; the turn-on time during the turn-on process of the power MOSFET is determined by using a turn-on time detection module; the turn-on energy loss is calculated according to the drain-source voltage, drain current, and turn-on time by using a turn-on energy loss calculation module; the aging state of the gate oxide of the power MOSFET is evaluated according to the drain-source voltage, drain current, and turn-on energy loss by using a gate oxide aging state evaluation module. By measuring the turn-on energy loss of the Si power MOSFET in real time, the present application can quickly, accurately, and non-destructively evaluate the aging state of the gate oxide, realizing real-time monitoring, quantitative analysis, and early warning. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of a device for evaluating the aging state of the gate oxide of a power MOSFET provided by an embodiment of the present application;

[0022] Figure 2 Schematic diagram of the turn-on time start point detection circuit provided by an embodiment of the present application;

[0023] Figure 3 Schematic diagram of the turn-on time end point detection circuit provided by an embodiment of the present application;

[0024] Figure 4 Schematic flow chart of a method for evaluating the gate oxide aging state of a power MOSFET provided by an embodiment of the present application. Detailed implementation manners

[0025] 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.

[0026] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0027] With the development of power electronic devices towards high power density, high frequency, and high efficiency, higher requirements are put forward for the real-time monitoring and accurate evaluation of the health state of devices. As a key parameter in the switching process of Si power MOSFETs, the turn-on energy loss is closely related to the gate oxide aging state. By measuring and analyzing the change of the turn-on energy loss in real time, the degree of gate oxide aging can be indirectly reflected, thus realizing non-destructive and on-line monitoring. This method can not only give early warning of potential failures, but also provide data support for optimizing device design, improving control strategies, and formulating maintenance plans, which has important engineering application value and theoretical research significance. Therefore, the present application proposes a device for evaluating the gate oxide aging state of a power MOSFET, which realizes real-time monitoring and quantitative evaluation of the gate oxide aging state by measuring the turn-on energy loss during the operation of the power MOSFET, and can accurately reflect the degree of gate oxide aging of the power MOSFET. As Figure 1 shown, the device for evaluating the gate oxide aging state of a power MOSFET includes the following modules.

[0028] A voltage detection module for real-time collecting the drain-source voltage V ds .

[0029] A current detection module for real-time collecting the drain current I d .

[0030] Turn-on time detection module, which is used to determine the turn-on time t during the turn-on process of the power MOSFET on .

[0031] Turn-on energy loss calculation module, connected (communicatively connected) to the voltage detection module, the current detection module, and the turn-on time detection module, and is used to calculate the turn-on energy loss according to the drain-source voltage, drain current, and turn-on time.

[0032] Gate oxide aging state evaluation module, connected (communicatively connected) to the voltage detection module, the current detection module, and the turn-on energy loss calculation module, and is used to evaluate the gate oxide aging state of the power MOSFET according to the drain-source voltage, drain current, and turn-on energy loss.

[0033] In this application, by measuring the turn-on energy loss during the operation of the Si power MOSFET, the real-time monitoring and quantitative evaluation of the gate oxide aging state can be realized, and the degree of gate oxide aging can be accurately reflected. This evaluation method has the advantages of high accuracy, real-time monitoring, strong adaptability, etc. Through innovative technical means, this application enables operators to identify potential fault hazards in the operation of the Si power MOSFET in real time and accurately, thereby effectively reducing the system maintenance cost and extending the service life of the equipment. At the same time, this application significantly improves the reliability and stability of the system, and provides a new solution for the health monitoring and evaluation of power electronic devices. The proposal of this technology not only fills the industry gap, but also injects new impetus into the innovation and development of the health monitoring technology of power electronic devices, and has important theoretical value and broad application prospects. In addition, this application is based on the strong correlation between the turn-on energy loss and the gate oxide aging for evaluation, has the characteristics of high precision and strong anti-interference ability, and the evaluation method is applicable to complex working conditions. At the same time, this evaluation method has low cost and is easy to integrate into the existing system, can be operated online without affecting the normal operation of power equipment. This application can provide aging trend and life prediction, can optimize the maintenance strategy, reduce unexpected shutdowns, extend the service life of the device, and thus significantly improve the reliability, economy, and maintenance efficiency of equipment operation.

[0034] In another exemplary embodiment of this application, the voltage detection module includes a voltage sensor, a high-precision conditioning circuit, and a data output unit; the voltage sensor is used to collect the voltage data V during the turn-on process of the Si power MOSFET in real time ds , and then it is converted into a digital signal by the high-precision conditioning circuit and output to the turn-on energy loss calculation module and the gate oxide aging state evaluation module by the data output unit.

[0035] In another exemplary embodiment of this application, the current detection module includes a current sensor, a high-precision conditioning circuit, and a data output unit; the current sensor is used to collect the current data I during the turn-on process of the Si power MOSFET in real timed , and then converted into digital signals by a high-precision conditioning circuit, and output to the turn-on energy loss calculation module and the gate oxide aging state evaluation module by the data output unit.

[0036] In another exemplary embodiment of the present application, the power MOSFET gate oxide aging state evaluation device further includes an aging model storage module; the aging model storage module is used to store different power MOSFET gate oxide aging states (aging models) and the corresponding drain-source voltage, drain current, and turn-on energy loss. The data stored in the aging model storage module is determined in advance through experimental tests. The specific process of obtaining the stored data is as follows:

[0037] (1) Determine the test conditions, including working condition parameters such as voltage and current, perform double-pulse experiments on healthy Si power MOSFETs, and collect voltage, current, and turn-on time data.

[0038] (2) Conduct gate oxide aging experiments on the Si power MOSFET module; perform double-pulse experiments on the aged Si power MOSFETs, and collect voltage, current, and turn-on time data.

[0039] (3) Process and analyze the collected data, and extract the relationship between the turn-on energy loss and the gate oxide aging state:

[0040] Degree of gate oxide aging = f(turn-on energy loss).

[0041] (4) Adjust the test conditions, including working conditions such as voltage and current, and construct a Si power MOSFET gate oxide aging model based on the turn-on energy loss considering different working condition parameters:

[0042] Degree of gate oxide aging = f(test conditions such as voltage and current, turn-on energy loss).

[0043] Based on the above, the gate oxide aging state evaluation module is used to compare the drain-source voltage, drain current, and turn-on energy loss with the drain-source voltage, drain current, and turn-on energy loss stored in the aging model storage module to determine the gate oxide aging state of the current power MOSFET. Specifically, determine the current working state of the power MOSFET device according to the drain-source voltage and drain current, and according to the current device working state, call the turn-on energy loss and the aging model for comparison, and determine the gate oxide aging state of the current device.

[0044] In another exemplary embodiment of the present application, the turn-on time detection module includes the following components.

[0045] The turn-on time starting point detection circuit is used to detect the drain-source voltage of the power MOSFET and determine the turn-on time starting point in the turn-on process of the power MOSFET according to the drain-source voltage of the power MOSFET.

[0046] The turn-on time end point detection circuit is used to detect the induced voltage generated by the parasitic inductance between the Kelvin source and the power source of the power MOSFET, and determine the turn-on time end point during the turn-on process of the power MOSFET according to the induced voltage.

[0047] The pulse synthesis circuit is used to synthesize the waveforms output by the on-time starting point detection circuit and the on-time end point detection circuit into a pulse signal; the width of the pulse signal is the on-time.

[0048] The opening time detection module also includes a digital-to-analog conversion unit and a data output unit. The digital-to-analog conversion unit is used to convert the signal output by the pulse synthesis circuit into a digital signal, which is output to the opening energy loss calculation module by the data output unit.

[0049] In another exemplary embodiment of the present application, a start-time detection circuit is connected in parallel to the drain and source of the Si power MOSFET. The start-time detection circuit includes a voltage divider circuit, a voltage follower circuit, and a high-speed communication optocoupler circuit.

[0050] The voltage divider circuit is used to input the drain-source voltage V of the power MOSFET ds The voltage is controlled within the power supply voltage of the voltage follower circuit and output to the voltage follower circuit.

[0051] The voltage follower circuit is used for buffering signal transmission between the voltage divider circuit and the high-speed communication optocoupler circuit, and outputting the received drain-source voltage to the high-speed communication optocoupler circuit.

[0052] The high-speed communication optocoupler circuit is used to determine the start point of the turn-on time according to the drain-source voltage.

[0053] In another exemplary embodiment of the present application, Figure 2 As shown, the voltage divider circuit includes a first resistor unit (corresponding to Figure 2 R1 in) and the second resistor unit (corresponding to Figure 2 The voltage follower circuit includes an operational amplifier (corresponding to Figure 2 The high-precision operational amplifier 1 in the high-speed communication optical coupling circuit includes a third resistor unit (corresponding to Figure 2 R3 in) and high-speed communication optocoupler (corresponding to Figure 2 High-speed communication optical coupler 1); the first resistance unit and the second resistance unit each include at least one resistor, and multiple resistors are connected in series and parallel to form the entire resistance unit.

[0054] One end of the first resistor unit is connected to the drain of the power MOSFET, and the other end of the first resistor unit is respectively connected to one end of the second resistor unit and the positive pole of the operational amplifier. The other end of the second resistor unit is grounded.

[0055] The output end of the operational amplifier is connected to one end of the third resistor unit. The other end of the third resistor unit is connected to the input end of the high-speed communication optocoupler. The output end of the high-speed communication optocoupler is connected to the input end of the pulse synthesis circuit.

[0056] The high-speed communication optocoupler is usually a current-mode optocoupler, and its trigger threshold is fixed. By adjusting the resistor between the voltage follower circuit and the high-speed communication optocoupler (such as Figure 2 R3 in it), it can be controlled at what drain-source voltage of the Si power MOSFET the high-speed communication optocoupler will act, so as to determine the starting point of the turn-on time. In addition, the high-speed communication optocoupler can also electrically isolate the mutual influence between the front and rear stage circuits and reduce the interference to the voltage signal.

[0057] In another exemplary embodiment of the present application, the turn-on time end detection circuit is connected in parallel between the Kelvin source and the power source of the Si power MOSFET (for devices without a Kelvin source, it can be connected in parallel between the power source and the power ground). There is a parasitic inductance between the Kelvin source and the power source. When current flows through the parasitic inductance, an induced voltage (V sS ) will be generated. By detecting the change time of the induced voltage, the current change during the turn-on process of the Si power MOSFET can be reflected. The turn-on time end detection circuit includes a voltage division circuit, a voltage follower circuit, and a high-speed communication optocoupler circuit. Similarly, by adjusting the resistor (such as Figure 3 R6 in it), it can be controlled at what induced voltage of the parasitic inductance of the Si power MOSFET the high-speed communication optocoupler will act, so as to determine the end point of the turn-on time.

[0058] As Figure 3 shown, the fourth resistor unit of the voltage division circuit of the turn-on time end detection circuit corresponds to Figure 3 R4 in it, the fifth resistor unit corresponds to Figure 3 R5 in it, the operational amplifier of the voltage follower circuit corresponds to Figure 3 the high-precision operational amplifier 2 in it, the third resistor unit of the high-speed communication optocoupler circuit corresponds to Figure 3 R6 in it, and the high-speed communication optocoupler corresponds to Figure 3 the high-speed communication optocoupler 2 in it.

[0059] The output end of the high-speed communication optocoupler of the turn-on time start point detection circuit and the output end of the high-speed communication optocoupler of the turn-on time end point detection circuit are connected to the input end of the pulse synthesis circuit. The pulse synthesis circuit is used to combine the waveforms output by the turn-on time start point detection circuit and the turn-on time end point detection circuit, convert them into digital signals through the digital-to-analog conversion unit, and then transmit the turn-on time t on information to the turn-on energy loss calculation module.

[0060] In another exemplary embodiment of the present application, the turn-on energy loss calculation module calculates the turn-on energy loss according to the outputs of the voltage detection module, the current detection module, and the turn-on time detection module. The expression for calculating the turn-on energy loss is as follows.

[0061]

[0062] In the formula, t eon represents the turn-on energy loss; V ds represents the drain-source voltage; I d represents the drain current; t on represents the turn-on time.

[0063] In another exemplary embodiment of the present application, a method for evaluating the gate oxide aging state of a power MOSFET based on a power MOSFET gate oxide aging state evaluation device is proposed. As Figure 4 shown, the method includes the following steps.

[0064] S1: Obtain the drain-source voltage during the turn-on process of the power MOSFET.

[0065] S2: Obtain the drain current during the turn-on process of the power MOSFET.

[0066] S3: Determine the turn-on time during the turn-on process of the power MOSFET.

[0067] S4: Calculate the turn-on energy loss according to the drain-source voltage, the drain current, and the turn-on time.

[0068] S5: Evaluate the gate oxide aging state of the power MOSFET according to the drain-source voltage, the drain current, and the turn-on energy loss.

[0069] In another exemplary embodiment of the present application, in step S5, evaluating the gate oxide aging state of the power MOSFET according to the drain-source voltage, the drain current, and the turn-on energy loss specifically includes:

[0070] Compare the drain-source voltage, drain current, and turn-on energy loss with those stored in the aging model storage module to determine the gate oxide aging state of the current power MOSFET; different gate oxide aging states of power MOSFETs and the corresponding drain-source voltages, drain currents, and turn-on energy losses are stored in the aging model storage module.

[0071] For the method disclosed in the embodiment, since it corresponds to the device disclosed in the embodiment, the description is relatively simple. For related parts, refer to the description of the device part.

[0072] In another exemplary embodiment of the present application, a computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for evaluating the gate oxide aging state of the power MOSFET.

[0073] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0074] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0075] Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, based on the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A power MOSFET gate oxide aging status evaluation device, characterized in that: include: Voltage detection module, used to collect the drain-source voltage of the power MOSFET in real time during the turn-on process; Current detection module, used to collect the drain current of the power MOSFET in real time during the on-state process; A turn-on time detection module is used to determine the turn-on time of the power MOSFET during the turn-on process; A turn-on energy loss calculation module, connected to the voltage detection module, the current detection module and the turn-on time detection module, for calculating the turn-on energy loss according to the drain-source voltage, the drain current and the turn-on time; The gate oxide aging state evaluation module is connected to the voltage detection module, the current detection module and the turn-on energy loss calculation module, and is used to evaluate the gate oxide aging state of the power MOSFET according to the drain-source voltage, the drain current and the turn-on energy loss.

2. The power MOSFET gate oxide aging state evaluation device according to claim 1, characterized in that: The power MOSFET gate oxide aging state evaluation device also includes an aging model storage module; the aging model storage module is used to store different power MOSFET gate oxide aging states and corresponding drain-source voltage, drain current and turn-on energy loss; The gate oxide aging state evaluation module is used to compare the drain-source voltage, drain current and turn-on energy loss with the drain-source voltage, drain current and turn-on energy loss stored in the aging model storage module to determine the gate oxide aging state of the current power MOSFET.

3. The power MOSFET gate oxide aging state evaluation device according to claim 1, characterized in that: The opening time detection module comprises: The turn-on time starting point detection circuit is used to detect the drain-source voltage of the power MOSFET and determine the turn-on time starting point in the turn-on process of the power MOSFET according to the drain-source voltage of the power MOSFET; The turn-on time end detection circuit is used to detect the induced voltage generated by the parasitic inductance between the Kelvin source and the power source of the power MOSFET, and determine the turn-on time end during the turn-on process of the power MOSFET according to the induced voltage; The pulse synthesis circuit is used to synthesize the waveforms output by the on-time starting point detection circuit and the on-time end point detection circuit into a pulse signal; the width of the pulse signal is the on-time.

4. The power MOSFET gate oxide aging state evaluation device according to claim 3, characterized in that: The opening time starting point detection circuit includes a voltage divider circuit, a voltage follower circuit and a high-speed communication optocoupler circuit; The voltage divider circuit is used to control the drain-source voltage of the power MOSFET within the power supply voltage of the voltage follower circuit and output it to the voltage follower circuit; The voltage follower circuit is used to buffer the signal transmission between the voltage divider circuit and the high-speed communication optocoupler circuit, and output the received drain-source voltage to the high-speed communication optocoupler circuit; The high-speed communication optocoupler circuit is used to determine the start point of the turn-on time according to the drain-source voltage.

5. The power MOSFET gate oxide aging state evaluation device according to claim 4, characterized in that: The voltage divider circuit includes a first resistance unit and a second resistance unit; the voltage follower circuit includes an operational amplifier; the high-speed communication optocoupler circuit includes a third resistance unit and a high-speed communication optocoupler; the first resistance unit and the second resistance unit each include at least one resistor; One end of the first resistance unit is connected to the drain of the power MOSFET, the other end of the first resistance unit is respectively connected to one end of the second resistance unit and the positive electrode of the operational amplifier, and the other end of the second resistance unit is grounded; The output end of the operational amplifier is connected to one end of the third resistor unit, the other end of the third resistor unit is connected to the input end of the high-speed communication optocoupler, and the output end of the high-speed communication optocoupler is connected to the input end of the pulse synthesis circuit.

6. The power MOSFET gate oxide aging state evaluation device according to claim 5, characterized in that: The structure of the on-time end point detection circuit is the same as that of the on-time start point detection circuit; The output end of the high-speed communication optocoupler of the on-time starting point detection circuit and the output end of the high-speed communication optocoupler of the on-time end point detection circuit are connected to the input end of the pulse synthesis circuit.

7. The power MOSFET gate oxide aging state evaluation device according to claim 1, characterized in that: The expression for calculating the opening energy loss is: Where, t eon Indicates the opening energy loss; V ds represents the drain-source voltage; I d represents the drain current; t on Indicates the opening time.

8. A method for evaluating the gate oxide aging state of a power MOSFET, characterized in that: include: Get the drain-source voltage of the power MOSFET during the turn-on process; Get the drain current of the power MOSFET during the turn-on process; Determine the turn-on time of the power MOSFET during the turn-on process; Calculate turn-on energy loss based on drain-source voltage, drain current and turn-on time; The gate oxide aging state of the power MOSFET is evaluated based on the drain-source voltage, drain current and turn-on energy loss.

9. The method for evaluating the gate oxide aging state of a power MOSFET according to claim 8, characterized in that: Evaluate the gate oxide aging state of the power MOSFET based on the drain-source voltage, drain current and turn-on energy loss, including: The drain-source voltage, drain current and turn-on energy loss are compared with the drain-source voltage, drain current and turn-on energy loss stored in the aging model storage module to determine the gate oxide aging state of the current power MOSFET; the aging model storage module stores different power MOSFET gate oxide aging states and the corresponding drain-source voltage, drain current and turn-on energy loss.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the gate oxide aging state of a power MOSFET described in any one of claims 8 to 9 is implemented.

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