Adjustable inductor clamp applied to double-pulse test, control circuit and control method
By designing an adjustable inductor fixture for dual pulse testing, using field effect transistors and microcontrollers to adjust the inductance value, the problem of difficult to accurately control the stray inductance of the test board in the prior art is solved, and a more accurate Test data and faster power module development progress.
Patent Information
- Application Number
- CN202411364422.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-02-14
AI Technical Summary
The prior art is difficult to accurately control stray inductors on dual-pulse test boards, resulting in slowing down the development progress of power modules.
An adjustable inductor fixture applied to dual pulse testing is designed. By connecting multiple field effect transistors to an adjustable inductor, the microcontroller controls the on-off or off of the field effect transistor and adjusts the inductor value of the adjustable inductor, thereby Accurately adjust the stray inductance of the dual-pulse test board.
It realizes accurate adjustment of the stray inductance of the dual-pulse test board, provides more accurate and reliable test data, and improves the progress and efficiency of power module development.
Smart Images
Figure CN119438634A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of double pulse testing of power modules, and in particular to an adjustable inductance fixture, a control circuit and a control method for double pulse testing. Background Art
[0002] In order to deeply study the impact of different stray inductances on the performance of power modules, it is usually necessary to design multiple double-pulse test boards with different stray inductances for testing. However, this test method only outputs approximate simulation values and it is difficult to accurately control the stray inductance on the double-pulse test board. As the requirements for the power module development cycle become more and more stringent, this test method has become increasingly inappropriate, slowing down the development progress of power modules. Summary of the invention
[0003] The purpose of this application is to provide an adjustable inductor fixture for double pulse testing to solve the problem that it is difficult to accurately control the stray inductance on the double pulse test board, which slows down the development progress of the power module.
[0004] To achieve the above objectives, this application provides the following solutions:
[0005] In a first aspect, the present application provides an adjustable inductor fixture for double pulse testing, comprising a double pulse testing board and an adjustable inductor module welded on the double pulse testing board;
[0006] The adjustable inductor module includes a plurality of field effect transistors and an adjustable inductor;
[0007] The source pins of all field effect transistors are connected to each other, and one end of the adjustable inductor is an output pin;
[0008] The drain pin of the field effect transistor is connected to the surface of the adjustable inductor, and the other end of the adjustable inductor is an input pin;
[0009] The gate pin of the field effect transistor is connected to a microcontroller; the microcontroller is used to control the on or off of each field effect transistor and adjust the inductance value of the adjustable inductor to adjust the stray inductance of the double pulse test board.
[0010] In a second aspect, the present application provides a control circuit for an adjustable inductance module, including: a control circuit integrated in a double pulse test board and an adjustable inductance module in an adjustable inductance fixture for double pulse testing;
[0011] The control circuit includes a rectifier circuit, a filter circuit, a DC-DC conversion circuit, a microcontroller, a differential amplifier circuit, a drive circuit, a voltage sensor, a signal amplifier and an analog-to-digital conversion circuit connected in sequence;
[0012] The control circuit controls the opening or closing of each field effect transistor in the adjustable inductor module according to the voltage signal, and adjusts the inductance value of the adjustable inductor in the adjustable module to adjust the stray inductance of the double pulse test board.
[0013] In a third aspect, the present application provides a control method for an adjustable inductance module, which is applied to the above-mentioned adjustable inductance fixture for double pulse testing, comprising:
[0014] Controlling the turning on or off of each field effect transistor in the adjustable inductor module in the adjustable inductor fixture applied to the double pulse test according to the voltage signal, and adjusting the inductance value of the adjustable inductor in the adjustable module;
[0015] Comparing the adjusted inductance value with the inductance command value to determine whether the adjusted inductance value is correct;
[0016] If yes, confirm that the inductance adjustment is complete and start the double pulse test;
[0017] If not, calibrate the adjusted inductance value.
[0018] According to the specific embodiments provided in the present application, the present application discloses the following technical effects: the present application connects multiple field effect transistors with an adjustable inductor, and the microcontroller adjusts the inductance value of the adjustable inductor by controlling the opening or closing of each field effect transistor, so as to accurately adjust the stray inductance of the double pulse test board, thereby effectively simulating the impact of different stray inductances on the power module, providing more accurate and reliable test data for the development and optimization of the power module, so that the inductance adjustment method can be more conveniently and quickly applied to the testing of the power module, thereby improving the development progress of the power module. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0020] Figure 1 A three-dimensional diagram of the appearance of an adjustable inductor module provided in one embodiment of the present application;
[0021] Figure 2 A schematic diagram of the internal structure of an adjustable inductor module provided in one embodiment of the present application;
[0022] Figure 3 A bottom view of an adjustable inductor module provided in one embodiment of the present application;
[0023] Figure 4 A front view of an adjustable inductor module provided in one embodiment of the present application;
[0024] Figure 5 A circuit topology diagram of an adjustable inductor module provided in an embodiment of the present application;
[0025] Figure 6 A schematic diagram of a control circuit of an adjustable inductance module provided in an embodiment of the present application;
[0026] Figure 7 A flow chart of a control method for an adjustable inductance module provided in one embodiment of the present application;
[0027] Figure 8 A usage scenario diagram provided for an embodiment of the present application;
[0028] Fig. 9 A schematic diagram of a control method for an adjustable inductor module provided in an embodiment of the present application in actual operation. DETAILED DESCRIPTION
[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0030] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0031] like Figure 1-Figure 5 As shown, an adjustable inductor fixture for double pulse testing provided in an embodiment of the present application includes a double pulse test board and an adjustable inductor module welded on the double pulse test board; the adjustable inductor module includes multiple field effect transistors 1 (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) 1 and an adjustable inductor 2; the source pins of all field effect transistors 1 are interconnected and connected to one end 3 of the adjustable inductor 2, and one end 3 of the adjustable inductor 2 is an output pin; the drain pin of the field effect transistor 1 is connected to the surface of the adjustable inductor 2 and to the other end 4 of the adjustable inductor 2, and the other end 4 of the adjustable inductor 2 is an input pin; the gate pin 5 of the field effect transistor 1 is connected to a microcontroller; the microcontroller is used to control the opening or closing of each field effect transistor 1, and adjust the inductance value of the adjustable inductor 2 to adjust the stray inductance of the double pulse test board.
[0032] The gate pin is used to control whether the MOSFET1 is turned on and determine the inductance of the device. The material for connecting the source pins of multiple MOSFET1 is also included. In this embodiment, the number of MOSFET1 is 10.
[0033] In an exemplary embodiment, the field effect transistor 1 is integrated into the adjustable inductance module by using a doping method, and an insulating layer is provided between each field effect transistor 1 .
[0034] In an exemplary embodiment, the drain pin of the field effect transistor 1 is connected to the surface of the adjustable inductor 2 through a bonding wire;
[0035] In an exemplary embodiment, the drain pin, the bonding wire, and the adjustable inductor 2 are cast in an integrated manner.
[0036] In an exemplary embodiment, the drain pins of each field effect transistor 1 are independent of each other.
[0037] In an exemplary embodiment, the inductance value of the adjustable inductor is equally divided into multiple parts; the number of equally divided parts is the same as the number of field effect transistors 1 .
[0038] The conductive channel of MOSFET1 is vertical, which facilitates the connection of the gate, source and drain with bonding wires and facilitates packaging into a device.
[0039] Furthermore, the sources of all MOSFETs 1 are connected together by welding.
[0040] The adjustable inductor module is welded to the dual pulse test board to form a fixture to achieve precise control of the inductance of the dual pulse test board, and the upper computer controls the on and off of MOSFET1 to control the inductance value of the adjustable inductor 2; the internal integrated inductor value is 16nH, which is divided into 20 parts, each part is 0.8nH, plus the inductance value of each gate pin to the integrated inductor is 0.2nH, so far, the device can control 20nH inductance; each MOSFET1 gate impedance is matched, and the error is controlled within 10%.
[0041] like Figure 6 As shown, the present application also provides a control circuit of an adjustable inductance module, including: a control circuit integrated in a double pulse test board and an adjustable inductance module in the above-mentioned adjustable inductance fixture applied to the double pulse test;
[0042] The control circuit includes a rectifier circuit, a filter circuit, a DC-DC converter circuit, a microcontroller, a differential amplifier circuit, a drive circuit, a voltage sensor, a signal amplifier, and an analog-to-digital converter (ADC) circuit connected in sequence;
[0043] The control circuit controls the on or off of each field effect transistor 1 in the adjustable inductor module according to the voltage signal, and adjusts the inductance value of the adjustable inductor 2 in the adjustable module to adjust the stray inductance of the double pulse test board.
[0044] like Figure 7 As shown, the present application also provides a control method for an adjustable inductance module, which is applied to the above-mentioned adjustable inductance fixture, including:
[0045] Step 701: Control the turning on or off of each field effect transistor 1 in the adjustable inductor module in the adjustable inductor fixture applied to the double pulse test according to the voltage signal, and adjust the inductance value of the adjustable inductor 2 in the adjustable module.
[0046] Step 702: Compare the adjusted inductance value with the inductance command value to determine whether the adjusted inductance value is correct. If so, execute step 703; if not, execute step 704.
[0047] Step 703: Determine that the inductance adjustment is completed and start the double pulse test.
[0048] Step 704: calibrate the adjusted inductance value.
[0049] In an exemplary embodiment, step 702 specifically includes: determining whether the error between the adjusted inductance value and the inductance command value is within a set error range; if so, determining that the adjusted inductance value is correct; if not, determining that the adjusted inductance value is incorrect.
[0050] In an exemplary embodiment, step 704 specifically includes: using the formula
[0051] Calibrate the adjusted inductance value; where L x is the real inductance value; Im is the logarithmic sign; f is the power frequency; Z xm The impedance measured by the test instrument; Z sc The short-circuit impedance measured by the test instrument; L xm is the inductance value measured by the test instrument; L sc It is the short-circuit inductance value measured by the test instrument.
[0052] Get L x Before that, you need to make the following definitions:
[0053] Let the open circuit impedance (impedance value measured by the detection circuit when the fixture is open circuit) be:
[0054] Let the short-circuit impedance (the impedance value measured by the detection circuit when the fixture is short-circuited):
[0055] Let the real impedance of the inductor under test be:
[0056] Let the detection circuit measure the impedance:
[0057] So the matrix and matrix The relationship is:
[0058]
[0059] The impedance relationship is:
[0060]
[0061] Among them, Z om is the open circuit impedance; Z sm is the short-circuit impedance; Z x is the real impedance of the inductor being measured; Z xm is the impedance measured by the test instrument; A, B, C, and D are assumed values and have no specific meaning; V1 is the voltage value measured by the test instrument; I1 is the current value measured by the test instrument; V2 is the voltage value corresponding to the real impedance; I2 is the current value corresponding to the real impedance.
[0062] Application scenarios of this application: Applied to the gate circuit and load capacitor circuit in double pulse test, such as Figure 8 shown.
[0063] The principle of the control method of the adjustable inductance module in actual operation is as follows Fig. 9 As shown, the actual steps include:
[0064] 1. The upper computer sends an inductance adjustment instruction to the lower computer.
[0065] 2. After receiving the instruction, the lower computer sends a voltage signal to the control circuit.
[0066] 3. The control circuit controls the on and off of MOSFET1 in the device according to the voltage signal to adjust the inductance value.
[0067] 4. After passing the protection circuit, detect the on and off of each MOSFET1 to ensure correct regulation.
[0068] 5. After confirming that the opening and closing are correct, the detection circuit determines the inductance detection value.
[0069] 6. The algorithm then compares the measured value fed back by the detection circuit with the instructions from the host computer.
[0070] 7. After the comparison is completed, send instructions to the host computer. If it is correct, do not perform automatic calibration. If it is incorrect, perform automatic calibration.
[0071] 8. After the inductance adjustment is completed, start the double pulse test.
[0072] This application not only breaks through the limitation that the stray inductance of the loop cannot be adjusted in the double pulse test, but also realizes the controllable adjustment of the inductance. Compared with the traditional adjustable inductor, this application has the advantages of small size and can be mounted on the board to form a test fixture, making it more suitable for use on compact circuit boards. In addition, this application integrates MOSFET1 and inductor in one module, so that the host computer can adjust the inductance value, and the adjustment step is only 1nH, which makes the adjustment more precise.
[0073] It is worth mentioning that the present application can also calibrate the test error according to the control method of the adjustable inductance module, ensure the accuracy of the host computer adjustment, and further improve the reliability and accuracy of the test. This design not only saves space, but also reduces costs and improves test efficiency.
[0074] In addition, the present application also has good stability and anti-interference ability, which can effectively reduce test errors and improve the accuracy of test results.
[0075] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.
[0076] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.
Claims
1. An adjustable inductance fixture for double pulse testing, characterized in that: It includes a double pulse test board and an adjustable inductance module welded on the double pulse test board; The adjustable inductor module includes a plurality of field effect transistors and an adjustable inductor; The source pins of all field effect transistors are connected to each other, and one end of the adjustable inductor is an output pin; The drain pin of the field effect transistor is connected to the surface of the adjustable inductor, and the other end of the adjustable inductor is an input pin; The gate pin of the field effect transistor is connected to a microcontroller; the microcontroller is used to control the on or off of each field effect transistor and adjust the inductance value of the adjustable inductor to adjust the stray inductance of the double pulse test board.
2. The adjustable inductance fixture for double pulse testing according to claim 1, characterized in that: The field effect transistor is integrated into the adjustable inductance module by using a doping method, and an insulating layer is provided between each field effect transistor.
3. The adjustable inductance fixture for double pulse testing according to claim 1, characterized in that: The drain pin of the field effect transistor is connected to the surface of the adjustable inductor through a bonding wire.
4. The adjustable inductance fixture for double pulse testing according to claim 3 is characterized in that: The drain pin, the bonding wire and the adjustable inductor are cast in an integrated manner.
5. The adjustable inductance fixture for double pulse testing according to any one of claims 3 to 4, characterized in that: The drain pins of each field effect transistor are independent of each other.
6. The adjustable inductance fixture for double pulse testing according to claim 1, characterized in that: The inductance value of the adjustable inductor is divided into multiple equal parts; the number of equal parts is the same as the number of field effect transistors.
7. A control circuit of an adjustable inductance module, characterized in that: include: A control circuit integrated in a double pulse test board and an adjustable inductance module in an adjustable inductance fixture for double pulse testing as described in any one of claims 1 to 6; The control circuit includes a rectifier circuit, a filter circuit, a DC-DC conversion circuit, a microcontroller, a differential amplifier circuit, a drive circuit, a voltage sensor, a signal amplifier and an analog-to-digital conversion circuit connected in sequence; The control circuit controls the opening or closing of each field effect transistor in the adjustable inductor module according to the voltage signal, and adjusts the inductance value of the adjustable inductor in the adjustable module to adjust the stray inductance of the double pulse test board.
8. A control method for an adjustable inductance module, characterized in that: The adjustable inductance fixture for double pulse testing according to any one of claims 1 to 6 comprises: Controlling the turning on or off of each field effect transistor in the adjustable inductor module in the adjustable inductor fixture applied to the double pulse test according to the voltage signal, and adjusting the inductance value of the adjustable inductor in the adjustable module; Comparing the adjusted inductance value with the inductance command value to determine whether the adjusted inductance value is correct; If yes, confirm that the inductance adjustment is complete and start the double pulse test; If not, calibrate the adjusted inductance value.
9. The control method of the adjustable inductance module according to claim 8, characterized in that: Comparing the adjusted inductance value with the inductance command value to determine whether the adjusted inductance value is correct specifically includes: Determining whether an error between the adjusted inductance value and the inductance command value is within a set error range; If so, determining that the adjusted inductance value is correct; If not, it is determined that the adjusted inductance value is incorrect.
10. The control method of the adjustable inductance module according to claim 8, characterized in that: Calibrating the adjusted inductance value specifically includes: Using the formula Calibrate the adjusted inductance value; where L x is the real inductance value; Im is the logarithmic sign; f is the power frequency; Z xm The impedance measured by the test instrument; Z sc The short-circuit impedance measured by the test instrument; L xm is the inductance value measured by the test instrument; L sc It is the short-circuit inductance value measured by the test instrument.