Detection circuit for gate-source leakage current of MOSFET (Metal Oxide Semiconductor Field Effect Transistor)

Abstract

The embodiment of the utility model discloses a detection circuit for gate-source leakage current of an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), which comprises a detection unit, a switch control unit, an indication unit and a detected unit, the detection unit is connected with the detected unit, the switch control unit is connected with the detection unit, and the indication unit is connected with the detected unit. By implementing the detection circuit provided by the embodiment of the utility model, the detection cost can be greatly reduced, the operation process is simplified, the detection efficiency and accuracy are improved, and powerful support is provided for guaranteeing the quality of electronic products.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device technology, and in particular to a detection circuit for gate-source leakage current of a MOSFET. Background Technology

[0002] MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) are widely used switching and amplifying devices in modern electronic circuits. Their stability and reliability are crucial for the proper operation of the entire circuit. Ideally, a MOSFET should have a very high resistance between its gate and source, meaning that almost no current flows when no voltage is applied. However, in practical applications, due to manufacturing defects, material aging, or the influence of the operating environment, an increase in gate-source leakage current may occur. This leakage current not only consumes unnecessary power but can also cause abnormal circuit function and even device failure. Therefore, accurately monitoring the gate-source leakage current of a MOSFET is of great significance for ensuring the safe operation of the circuit and improving the reliability of the system.

[0003] Traditional methods for detecting MOSFET gate-source-drain current typically rely on precision ammeters to measure weak current signals. While this method provides relatively accurate measurement results, it also has several significant limitations: high-precision ammeters are expensive, increasing overall testing costs; the acquired data needs to be transmitted to a host computer for analysis, and additional software is required to implement alarm functions when an anomaly is detected, which undoubtedly increases the complexity of the system design; these processes often require specialized technical personnel, hindering rapid on-site detection and maintenance; and the entire process, from data acquisition and transmission to final display and alarm, is time-consuming and cannot meet the need for immediate feedback.

[0004] Therefore, it is necessary to design a new circuit that significantly reduces testing costs, simplifies the operation process, and improves testing efficiency and accuracy, thus providing strong support for ensuring the quality of electronic products. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a detection circuit for MOSFET gate-source leakage current.

[0006] To solve the above-mentioned technical problems, the purpose of this utility model is achieved through the following technical solution: providing a detection circuit for MOSFET gate-source leakage current, including: a detection unit, a switch control unit, an indicator unit, and a unit under test, wherein the detection unit is connected to the unit under test, the switch control unit is connected to the detection unit, and the indicator unit is connected to the unit under test.

[0007] A further technical solution includes a filtering unit connected between the detected unit and the indicating unit.

[0008] A further technical solution is as follows: the switch control circuit includes a switch element.

[0009] The further technical solution is as follows: the switching device includes a transistor Q2, the emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is connected to the detection unit; the base of the transistor Q2 is connected to a resistor R4, and the base of the transistor Q2 is also connected to a resistor R5 with one end grounded.

[0010] A further technical solution is as follows: the detection unit includes a voltage divider resistor R1, a voltage divider resistor R3, and a sampling resistor R2. One end of the voltage divider resistor R1 is connected to one end of the voltage divider resistor R3, and the other end of the voltage divider resistor R3 is connected to the collector of the transistor Q2. One end of the sampling resistor R2 is connected between the voltage divider resistor R1 and the voltage divider resistor R3, and the other end of the sampling resistor R2 is connected to the unit being detected.

[0011] A further technical solution is that the sampling resistor R2 is also connected in parallel with a diode D2.

[0012] The further technical solution is as follows: the detected unit includes a MOS transistor Q1, the gate of the MOS transistor Q1 is connected to the sampling resistor R2, the source of the MOS transistor Q1 is connected to the voltage divider resistor R1, the source of the MOS transistor Q1 is also connected to a power supply, and the drain of the MOS transistor Q1 is connected to the filter unit.

[0013] The further technical solution is as follows: the filtering unit includes a filtering resistor R6 with one end grounded and a filtering capacitor C1, and the other ends of the filtering resistor R6 and the filtering capacitor C1 are respectively connected between the detected unit and the indicating unit.

[0014] A further technical solution is that the indicating unit includes an indicator light.

[0015] A further technical solution is that a resistor R6 is connected between the indicator light and the detected unit.

[0016] The advantages of this invention compared to existing technologies are as follows: This invention achieves automatic detection by setting up a detection unit, a switch control unit, an indicator unit, and a unit to be detected, and by rationally connecting these units; the detection unit is connected to the unit to be detected, enabling real-time monitoring of the status of the device under test and achieving automated detection; the switch control unit is connected to the detection unit, automatically controlling the detection process and reducing the tedious steps of manual operation; the indicator unit intuitively displays the detection results through indicator lights, making abnormal states immediately apparent and avoiding human error; this design relies on simple peripheral circuitry, significantly reducing detection costs, simplifying the operation process, and improving detection efficiency and accuracy, thus ensuring the quality of electronic products.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic block diagram of a MOSFET gate-source leakage current detection circuit provided for an embodiment of this utility model;

[0020] Figure 2 A specific circuit schematic diagram of a MOSFET gate-source leakage current detection circuit provided for an embodiment of this utility model;

[0021] Explanation of the markings in the image:

[0022] 10. Detection unit; 20. Switch control unit; 30. Indicator unit; 40. Detected unit; 50. Filtering unit. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0024] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0025] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] MOSFETs are commonly used switching and amplifying components in modern electronic circuits. Ideally, they should have high resistance between their gate and source to prevent leakage current. In practical applications, leakage current may increase due to manufacturing defects or environmental factors, affecting circuit performance and leading to device failure. Traditional leakage current detection methods use high-precision ammeters, which are accurate but costly and complex. This method requires data transmission and additional software support, increasing the complexity of system design. The entire detection process is time-consuming and unsuitable for rapid on-site testing and maintenance.

[0028] Therefore, this utility model provides a detection circuit for MOSFET gate-source leakage current, which significantly reduces detection costs, simplifies the operation process, and improves detection efficiency and accuracy, providing strong support for ensuring the quality of electronic products.

[0029] Specifically, this circuit effectively reduces complexity and cost by employing a simple detection unit 10 and a switch control unit 20. The filter unit 50 ensures the stability of the detection signal, reduces interference, and improves accuracy. The detection circuit uses low-cost components composed of transistors and voltage divider resistors, simplifying circuit design and manufacturing. The switch control unit 20 enables rapid switching, reducing unnecessary operation steps and improving operational efficiency. The design of the sampling resistor and diode improves the accuracy of leakage current detection, ensuring accurate measurement. Using a MOSFET as the detected unit 40, combined with filtering, effectively improves the stability and reliability of the circuit. The indicator unit 30 provides intuitive display of the detection results via indicator lights, reducing human error and improving detection efficiency. This comprehensively optimized circuit design provides reliable assurance for the quality of electronic products while reducing the cost and operational difficulty of testing equipment.

[0030] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0031] Please see Figure 1 A detection circuit for MOSFET gate-source leakage current includes: a detection unit 10, a switch control unit 20, an indicator unit 30, and a detected unit 40. The detection unit 10 is connected to the detected unit 40, the switch control unit 20 is connected to the detection unit 10, and the indicator unit 30 is connected to the detected unit 40.

[0032] In one embodiment, please refer to Figure 1 The aforementioned detection circuit for MOSFET gate-source leakage current further includes a filter unit 50, which is connected between the detected unit 40 and the indicating unit 30.

[0033] Specifically, the detection unit 10 is one of the core components of the entire system. It is directly connected to the unit under test 40 (i.e., the MOSFET under test) to monitor the leakage current between the gate and source of the MOSFET and convert this physical quantity into an easily processed electrical signal. Through this conversion, accurate capture and subsequent analysis of the leakage current value can be achieved.

[0034] The switch control unit 20 is responsible for providing the necessary control signals, and its EN port is connected to an external control system or user interface. Upon receiving an appropriate trigger signal, the switch control unit 20 activates the entire detection process, allowing power to be supplied to the circuit and initiating the detection procedure. This design ensures that detection only occurs when needed, thereby saving energy and extending equipment life.

[0035] The unit under test 40 refers to the actual MOSFET device to be tested. It is the most critical part of the entire testing process because all measurement data originates from it. Depending on the different models and specific parameters of the MOSFET, the settings within the testing unit 10 can be adjusted to adapt to different testing requirements.

[0036] The indicator unit 30 typically includes one or more LEDs to visually display the current detection status. Under normal operating conditions, if the gate-source leakage current of the MOSFET remains within a preset safe range, the LED will remain lit; conversely, if an abnormally high leakage current is detected, the LED will turn off, thereby alerting the operator to potential problems.

[0037] The aforementioned detection circuit further integrates a filter unit 50. This unit, located between the detected unit 40 and the indicating unit 30, is specifically designed to filter out transient spikes or other forms of noise interference that may occur in the circuit. This not only helps improve the accuracy of the detection results but also protects sensitive components from damage, ensuring the stability and reliability of the system.

[0038] In summary, the MOSFET gate-source leakage current detection circuit provided in this embodiment achieves efficient and accurate leakage current detection capabilities through the synergistic effect of its carefully designed functional modules. It also provides a clear and intuitive status feedback mechanism, greatly enhancing the user experience. Furthermore, for applications requiring higher accuracy and less interference, a filter unit 50 can be added to further enhance overall performance.

[0039] In one embodiment, please refer to Figure 2 The aforementioned switch control circuit includes a switch element.

[0040] In one embodiment, please refer to Figure 2 The aforementioned switching device includes a transistor Q2, the emitter of which is grounded, and the collector of which is connected to the detection unit 10; the base of the transistor Q2 is connected to a resistor R4, and the base of the transistor Q2 is also connected to a resistor R5 with one end grounded.

[0041] In one embodiment, please refer to Figure 2 The detection unit 10 mentioned above includes a voltage divider resistor R1, a voltage divider resistor R3, and a sampling resistor R2. One end of the voltage divider resistor R1 is connected to one end of the voltage divider resistor R3, and the other end of the voltage divider resistor R3 is connected to the collector of the transistor Q2. One end of the sampling resistor R2 is connected between the voltage divider resistor R1 and the voltage divider resistor R3, and the other end of the sampling resistor R2 is connected to the detection unit 40.

[0042] In one embodiment, please refer to Figure 2 The sampling resistor R2 mentioned above is also connected in parallel with diode D2.

[0043] In one embodiment, please refer to Figure 2 The aforementioned detection unit 40 includes a MOS transistor Q1, the gate of which is connected to the sampling resistor R2, the source of which is connected to the voltage divider resistor R1, the source of which is also connected to a power supply, and the drain of which is connected to the filter unit 50.

[0044] In one embodiment, please refer to Figure 2The aforementioned filter unit 50 includes a filter resistor R6 with one end grounded and a filter capacitor C1. The other ends of the filter resistor R6 and the filter capacitor C1 are respectively connected between the detected unit 40 and the indicating unit 30.

[0045] In one embodiment, please refer to Figure 2 The aforementioned indicator unit 30 includes indicator lights.

[0046] In one embodiment, please refer to Figure 2 A resistor R6 is connected between the aforementioned indicator light and the detected unit 40.

[0047] Specifically, the control signal is provided by the EN terminal. When this terminal is high, transistor Q2 (assumed to be an NPN transistor in this embodiment) is turned on. At this time, the power supply voltage provided by the power terminal can reach up to 20V, but the specific voltage depends on the actual application requirements. The power supply voltage is supplied to the detection circuit through the collector-emitter path of transistor Q2.

[0048] When the leakage current between the gate (G) and source (S) of MOSFET Q1 is within the normal range, resistors R1 and R3 form a voltage divider network. The difference between the voltage divided by the resistor and the power supply voltage provided at the power terminal is greater than the turn-on voltage (i.e., threshold voltage) of the MOSFET Q1 being tested.

[0049] in this case:

[0050] The drain (D) and source (S) of MOSFET Q1 will be connected.

[0051] The drain terminal voltage of the circuit under test will be equal to the power value minus the drain-source voltage drop (VDS) inside the MOSFET Q1.

[0052] Because of the filter unit 50 and the indicator unit 30 in the circuit, the LED will light up, indicating that the GS leakage current is in a normal state.

[0053] If the leakage current between the gate (G) and source (S) of MOSFET Q1 increases abnormally, a large voltage difference will be generated across the sampling resistor R2. This will lead to the following situation:

[0054] The gate voltage of MOSFET Q1 is increased, so that the voltage difference between the gate and the source is less than the turn-on voltage of MOSFET Q1.

[0055] Therefore, the drain and source of MOSFET Q1 will not conduct, no current flows through the drain, and there is no voltage output at the drain terminal.

[0056] The result is that the LED does not light up, indicating that there is an abnormal leakage current between the gate and source of the tested MOSFET Q1.

[0057] The detection threshold can be set by adjusting the values ​​of the voltage divider resistors R1 and R3 and the sampling resistor R2, depending on the controlled leakage current range and the gate-source turn-on voltage of the specific device. This flexibility allows for testing MOSFETs Q1 of different specifications, improving the applicability and cost-effectiveness of the method.

[0058] This circuit can detect extremely minute changes in leakage current, which is crucial for ensuring MOSFET quality, as even very small leakage currents can affect device performance or lifespan. This detection solution can be implemented at any point on the production line without stopping the process. Intuitive LED indicators allow workers to immediately identify the location of faulty components, improving efficiency and reducing waste.

[0059] Because the entire circuit design takes power consumption into account, multiple MOSFETs can be tested simultaneously, even when using a small-capacity power supply. This feature is particularly useful for portable devices or environments with limited resources.

[0060] In summary, the detection circuit of this embodiment is suitable for large-scale production and quality control.

[0061] The aforementioned detection circuit for MOSFET gate-source leakage current achieves automatic detection by configuring a detection unit 10, a switch control unit 20, an indicator unit 30, and a unit under test 40, and by rationally connecting these units. The detection unit 10, connected to the unit under test 40, can monitor the status of the device under test in real time, enabling automated detection. The switch control unit 20, connected to the detection unit 10, automatically controls the detection process, reducing the tedious steps of manual operation. The indicator unit 30 visually displays the detection results using indicator lights, making abnormal states immediately apparent and avoiding human error. This design relies on simple peripheral circuitry, significantly reducing detection costs, simplifying the operation process, and improving detection efficiency and accuracy, thus ensuring the quality of electronic products.

[0062] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A detection circuit for MOSFET gate-source leakage current, characterized in that, include: The system includes a detection unit, a switch control unit, an indicator unit, and a unit under test. The detection unit is connected to the unit under test, the switch control unit is connected to the detection unit, and the indicator unit is connected to the unit under test.

2. The detection circuit for MOSFET gate-source leakage current according to claim 1, wherein, It also includes a filtering unit, which is connected between the detected unit and the indicating unit.

3. The detection circuit for MOSFET gate-source leakage current according to claim 2, wherein, The switch control unit includes a switch element.

4. The detection circuit for MOSFET gate-source leakage current according to claim 3, wherein, The switching device includes a transistor Q2, the emitter of which is grounded, and the collector of which is connected to the detection unit; the base of the transistor Q2 is connected to a resistor R4, and the base of the transistor Q2 is also connected to a resistor R5 with one end grounded.

5. The detection circuit for MOSFET gate-source leakage current according to claim 4, wherein, The detection unit includes a voltage divider resistor R1, a voltage divider resistor R3, and a sampling resistor R2. One end of the voltage divider resistor R1 is connected to one end of the voltage divider resistor R3, and the other end of the voltage divider resistor R3 is connected to the collector of the transistor Q2. One end of the sampling resistor R2 is connected between the voltage divider resistor R1 and the voltage divider resistor R3, and the other end of the sampling resistor R2 is connected to the unit being detected.

6. The detection circuit for MOSFET gate-source leakage current according to claim 5, wherein, The sampling resistor R2 is also connected in parallel with a diode D2.

7. A detection circuit for MOSFET gate-source leakage current according to claim 5, characterized in that, The detected unit includes a MOS transistor Q1, the gate of which is connected to the sampling resistor R2, the source of which is connected to the voltage divider resistor R1, the source of which is also connected to a power supply, and the drain of which is connected to the filter unit.

8. The detection circuit for MOSFET gate-source leakage current according to claim 7, wherein, The filtering unit includes a filter resistor R6 with one end grounded and a filter capacitor C1. The other ends of the filter resistor R6 and the filter capacitor C1 are respectively connected between the detected unit and the indicating unit.

9. The detection circuit for MOSFET gate-source leakage current according to claim 8, wherein, The indicating unit includes indicator lights.

10. The detection circuit for MOSFET gate-source leakage current according to claim 9, wherein, A resistor R6 is connected between the indicator light and the unit being tested.

Images