Continuous drain current test circuit
By designing a continuous drain current test circuit including DC power supply, programmable power supply, oscilloscope and MOSFET devices, the problem of lack of standard testing methods in the prior art is solved, and an effective evaluation of the stability and performance of MOSFET devices is achieved.
Patent Information
- Application Number
- CN202421285502.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-06
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-06-06
AI Technical Summary
The prior art lacks the continuous drain current testing circuit and method of standard MOSFET devices, which makes it impossible to effectively test the stability of MOSFET devices.
A continuous drain current testing circuit is designed, including DC power supply, program-controlled power supply, oscilloscope and MOSFET device. The current probe and voltage probe of the oscilloscope are connected to both ends of the MOSFET device, and the test current value, test voltage value and test power-up time are measured to achieve the testing of the continuous drain current capability of the MOSFET device.
Through this test circuit, the current and voltage waveforms of the MOSFET device can be accurately monitored, ensuring the accuracy of the test current and time, and thus effectively evaluating the stability and performance of the MOSFET device.
Smart Images
Figure CN222926816U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of application tests of electronic devices, and particularly relates to a continuous drain current test circuit. Background Art
[0002] Mosfet (Metal-Oxide-Semiconductor Field-Effect Transistor) devices are widely used in analog circuits and digital circuits. The stability of Mosfet devices directly affects the stability of the entire circuit.
[0003] However, there is currently no standard continuous drain current test circuit and method for MOSFET devices, nor are there standard test devices.
[0004] In view of this, it is necessary to propose a feasible continuous drain current test circuit. Summary of the Utility Model
[0005] For this reason, the purpose of the utility model is to at least to some extent solve the deficiencies in the prior art, and thus propose a continuous drain current test circuit.
[0006] To achieve the above purpose, a technical solution adopted by the utility model is:
[0007] The utility model discloses a continuous drain current test circuit, which includes a DC power supply, a programmable power supply, an oscilloscope and a MOSFET device. The oscilloscope is connected to both ends of the MOSFET device through a current probe and a voltage probe, and is used to measure the test current value passing through the MOSFET device, the test voltage value across the MOSFET device, and the test power-on time. The MOSFET device includes a gate, a source and a drain. The gate is connected to the positive pole of the DC power supply, the source is connected to the negative pole of the DC power supply and the negative pole of the programmable power supply, and the drain is connected to the positive pole of the programmable power supply.
[0008] Further, the current probe of the oscilloscope is connected between the source and the negative pole of the programmable power supply.
[0009] Further, the test current capacity of the current probe is greater than the test current value.
[0010] Further, the voltage probe of the oscilloscope is connected between the drain and the source.
[0011] Further, the DC power supply is a low-power DC power supply.
[0012] Further, the operating voltage value of the DC power supply is greater than the turn-on voltage of the MOSFET device.
[0013] Further, the operating voltage value of the DC power supply is 10 - 12V.
[0014] Further, the programmable power supply is a high-power programmable power supply.
[0015] Further, the output current value capacity of the programmable power supply is greater than the test current value.
[0016] Further, the power-on time capacity of the programmable power supply is greater than the test power-on time.
[0017] The utility model discloses a continuous drain current test circuit, which includes a DC power supply, a programmable power supply, an oscilloscope and a MOSFET device. The oscilloscope is connected to both ends of the MOSFET device through a current probe and a voltage probe, and is used to measure the test current value passing through the MOSFET device, the test voltage value at both ends of the MOSFET device, and the test power-on time. The MOSFET device includes a gate, a source and a drain. The gate is connected to the positive pole of the DC power supply, the source is connected to the negative pole of the DC power supply and the negative pole of the programmable power supply, and the drain is connected to the positive pole of the programmable power supply. Through the test circuit provided by the utility model, the DC power supply in the test circuit turns on the MOSFET device, the programmable power supply is used to control the output time, and the oscilloscope is used to monitor the voltage at both ends of the MOSFET device, the current value passing through the MOSFET device and the duration, so as to complete the whole experimental process, and further realize the continuous drain current capacity test. Description of the Drawings
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.
[0019] Figure 1 is the circuit diagram of the continuous drain current test circuit of the present utility model;
[0020] Figure 2 is a waveform diagram of the continuous drain current test circuit of the present utility model;
[0021] Figure 3 is another waveform diagram of the continuous drain current test circuit of the present utility model.
[0022] The reference numerals in the drawings are represented as: 1. DC power supply; 2. Programmable power supply; 3. MOSFET device. Detailed implementation manners
[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0024] It should be noted that the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.
[0025] Please refer to Figures 1 to 3 , the present invention provides a continuous drain current test circuit, including a DC power supply 1, a programmable power supply 2, an oscilloscope, and a MOSFET device 3. The oscilloscope is connected to both ends of the MOSFET device 3 through a current probe and a voltage probe, and is used to measure the test current value passing through the MOSFET device 3, the test voltage value across the MOSFET device 3, and the test power-on time. The MOSFET device 3 includes a gate, a source, and a drain. The gate is connected to the positive pole of the DC power supply 1, the source is connected to the negative pole of the DC power supply 1 and the negative pole of the programmable power supply 2, and the drain is connected to the positive pole of the programmable power supply 2.
[0026] In this embodiment, the continuous drain current test circuit includes a DC power supply 1, a programmable power supply 2, an oscilloscope, and a MOSFET device 3. The DC power supply 1 is used to turn on the MOSFET device 3, and the programmable power supply 2 controls the test current and the test time. The oscilloscope is connected to both ends of the MOSFET device 3 through a current probe and a voltage probe, and is used to monitor the test voltage value across the MOSFET device 3, the test current value passing through the MOSFET device 3, and the test power-on time, that is, the current time passing through the MOSFET device 3, so as to complete the entire test process and realize the continuous drain current capability test. Among them, the DC power supply 1 is a low-power DC power supply, and the programmable power supply 2 is a high-power programmable power supply.
[0027] Specifically, the MOSFET device 3 includes a gate, a source, and a drain. The gate, source, and drain of the MOSFET device 3 are respectively connected to the DC power supply 1, the positive electrode, and the negative electrode of the programmable power supply 2. Both ends of the oscilloscope are respectively connected to the drain and the source of the MOSFET device 3, so that the oscilloscope can capture the voltage and current waveforms at both ends of the MOSFET device 3, and then confirm whether there are any abnormalities in the voltage and current waveforms. If the waveforms fluctuate abnormally, it is necessary to confirm whether the MOSFET device 3 fails. If the waveforms are smooth and flat, the MOSFET device 3 works normally during the test. Then confirm that the voltage and current waveforms and the waveform duration are within the test requirements to complete the test.
[0028] Further, the current probe of the oscilloscope is connected between the source and the negative electrode of the programmable power supply 2.
[0029] In this embodiment, the oscilloscope includes a current probe. The current probe converts the current change in the circuit to be measured into a voltage signal that can be read by the oscilloscope by sensing the current change. Therefore, the oscilloscope current probe is mainly used to measure the test current value and the test power-on time in the circuit. Specifically, the current probe is connected between the programmable power supply 2 and the source of the MOSFET device 3, and the oscilloscope single mode is used to capture the current waveform to monitor the current value and the duration passing through both ends of the MOSFET device 3.
[0030] Further, the test current capacity of the current probe is greater than the test current value.
[0031] In this embodiment, the test current capacity of the current probe needs to be greater than the measured current value to accurately measure the current value passing through the MOSFET device 3. If the test current capacity of the current probe cannot reach the test current value, equal-length test lines can be used in parallel to divide the test current evenly and then measure.
[0032] Further, the voltage probe of the oscilloscope is connected between the drain and the source.
[0033] In this embodiment, the oscilloscope includes a voltage probe. The current voltage probe converts the voltage change in the circuit to be measured into a voltage signal that can be read by the oscilloscope by sensing the voltage change. Therefore, the oscilloscope voltage probe is mainly used to measure the test voltage value in the circuit. Specifically, the voltage probe is connected between the drain and the source of the MOSFET device 3, and the oscilloscope single mode is used to capture the voltage waveform to monitor the test voltage value and the test power-on time (the time when the current continuously passes) at both ends of the MOSFET device 3.
[0034] Further, the working voltage value of the DC power supply 1 is greater than the turn-on voltage of the MOSFET device 3.
[0035] In this embodiment, a DC power supply 1 provides a working voltage between the gate and source of the MOSFET device 3, and the working voltage value of the DC power supply 1 needs to be greater than the turn-on voltage of the MOSFET device 3, so as to turn on the MOSFET device 3.
[0036] Further, the working voltage value of the DC power supply 1 is 10 - 12V.
[0037] In this embodiment, the working voltage value between the gate and source of the MOSFET device 3 provided by the DC power supply 1 can be 10V or 12V, and the specific voltage value is determined according to the rated working voltage of the gate and source of the MOSFET device 3.
[0038] Further, the output current value capacity of the programmable power supply 2 is greater than the test current value.
[0039] In this embodiment, the programmable power supply 2 provides a stable and continuous output current value between the drain and source of the MOSFET device 3, and the specific current value is determined according to the specification sheet of the MOSFET device 3 or the test requirements. And the output current value capacity of the programmable power supply 2 needs to be greater than the test current value, so that the test circuit can accurately test.
[0040] Further, the power-on time capacity of the programmable power supply 2 is greater than the test power-on time.
[0041] In this embodiment, by programming the programmable power supply 2, the power-on time between the drain and source of the MOSFET device 3 is controlled. The specific power-on time is determined according to the specification sheet of the MOSFET device 3 or the test requirements, and the power-on time capacity of the programmable power supply 2 is greater than the test power-on time, so that the test circuit can accurately test.
[0042] Specifically, the calculation method of the continuous drain current of the MOSFET device 3 is as follows:
[0043] The continuous drain current is denoted as ID in the data sheet of the power MOSFET device 3. For the MOSFET device 3, usually the continuous drain current ID is a calculated value. When the package and chip size of the MOSFET device 3 are certain, such as for packages with exposed copper on the bottom like DPAK, TO220, D2PAK, DFN5*6, etc., then the thermal resistance Rth(J-C) from the junction to the exposed copper of the MOSFET device 3 is a definite value. According to the maximum allowable working junction temperature TJ of the silicon wafer and the temperature TC of the exposed copper, generally at room temperature 25°C, the maximum allowable power dissipation PD of the device can be obtained.
[0044] Formula:
[0045] When the maximum continuous drain current flows through MOSFET device 3, the maximum power dissipation is PD:
[0046] Formula: PD=ID 2 ×R DS(ON)-TJ(Max)
[0047] Therefore, the two formulas can be combined to obtain the calculation formula for the maximum continuous drain current ID:
[0048]
[0049] Among them, R DS(ON) is the on-resistance of MOSFET device 3 at the maximum operating junction temperature TJ.
[0050] The utility model provides a continuous drain current test circuit, including a direct current power supply, a programmable power supply, an oscilloscope and a MOSFET device. The oscilloscope is connected to the two ends of the MOSFET device through a current probe and a voltage probe, and is used to measure the test current value passing through the MOSFET device and the test voltage value at both ends of the MOSFET device and the test power-on time. The MOSFET device includes a gate, a source and a drain. The gate is connected to the positive electrode of the direct current power supply, the source is connected to the negative electrode of the direct current power supply and the negative electrode of the programmable power supply, and the drain is connected to the positive electrode of the programmable power supply. Through the test circuit provided by the utility model, the direct current power supply in the test circuit turns on the MOSFET device, and the programmable power supply is used to control the test current and test time. The oscilloscope is used to monitor the voltage at both ends of the MOSFET device and the current value and duration passing through the MOSFET device, thereby completing the entire experimental process, and then realizing the continuous drain current capability test.
[0051] It should be noted that the various embodiments in the present invention are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.
[0052] It should also be noted that in the content of the present utility model, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.
[0053] The above description of the disclosed embodiments enables those skilled in the art to implement or use the content of the present utility model. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined in the content of the present utility model can be implemented in other embodiments without departing from the spirit or scope of the content of the present utility model. Therefore, the content of the present utility model will not be limited to these embodiments shown in the content of the present utility model, but rather to the broadest scope consistent with the principles and novel features disclosed in the content of the present utility model.
Claims
1. A continuous drain current test circuit, characterized in that: The invention comprises a direct current power supply, a programmable power supply, an oscilloscope and a MOSFET device. The oscilloscope is connected to the two ends of the MOSFET device through a current probe and a voltage probe, and is used to measure the test current value passing through the MOSFET device, the test voltage value at the two ends of the MOSFET device and the test power-on time. The MOSFET device comprises a gate, a source and a drain. The gate is connected to the positive electrode of the direct current power supply, the source is connected to the negative electrode of the direct current power supply and the negative electrode of the programmable power supply, and the drain is connected to the positive electrode of the programmable power supply.
2. The continuous drain current test circuit according to claim 1, characterized in that: The current probe of the oscilloscope is connected between the source electrode and the negative electrode of the programmable power supply.
3. The continuous drain current test circuit according to claim 2, characterized in that: The test current capability of the current probe is greater than the test current value.
4. The continuous drain current test circuit according to claim 1, characterized in that: The voltage probe of the oscilloscope is connected between the drain and the source.
5. The continuous drain current test circuit according to claim 1, characterized in that: The DC power supply is a low-power DC power supply.
6. The continuous drain current test circuit according to claim 1, characterized in that: The operating voltage value of the DC power supply is greater than the turn-on voltage of the MOSFET device.
7. The continuous drain current test circuit according to claim 6, characterized in that: The working voltage value of the DC power supply is 10-12V.
8. The continuous drain current test circuit according to claim 1, characterized in that: The programmable power supply is a high-power programmable power supply.
9. The continuous drain current test circuit according to claim 1, characterized in that: The output current value capability of the programmable power supply is greater than the test current value.
10. The continuous drain current test circuit according to claim 1, characterized in that: The power-on time capability of the programmable power supply is greater than the test power-on time.