PCB circuit board, diode characteristic testing system and method

Abstract

The present invention provides a PCB circuit board and diode characteristic testing system and method, comprising: a power switch tube, an adjustable loop resistor, an adjustable main loop inductor, an adjustable power supply module, a drive signal generating module, a diode to be tested, and an adjustable diode junction capacitance; one end of the power switch tube is connected to the positive electrode of the power supply module via the loop resistor and the main loop inductor, and the other end is connected to the negative electrode of the power supply module; the drive signal generating module is connected to the drive end of the power switch tube to provide a drive signal for the power switch tube; the cathode of the diode to be tested is connected to the positive electrode of the power supply module, and the anode is the connection node of the loop resistor and the main loop inductor; the diode junction capacitance is connected in parallel to both ends of the diode to be tested for adjusting the size of the diode junction capacitance. The present invention saves testing time and cost, has a simple and easy operation process, highly accurate test results, a wider range of applications, and strong practicality.

Description

Technical Field

[0001] The present invention relates to the field of power supply applications, and in particular to a PCB circuit board and a diode characteristic testing system and method. Background Art

[0002] In power supply applications, including adapters, PC power supplies, chargers, and other applications with power levels ranging from tens of watts to hundreds of watts, secondary rectification usually uses diodes (mostly Schottky diodes) as output rectification. Therefore, the performance of the diodes needs to be tested.

[0003] For in-application testing, a test bench is typically used or a Schottky diode is replaced in an existing product to test its performance in the application and determine whether a diode of a certain specification can be replaced accordingly. However, when developing new diode products, simply examining static device parameters, such as forward voltage drop and reverse leakage current, cannot clearly reflect the device's dynamic performance in a specific application and requires consideration of the specific application environment.

[0004] Existing test platforms don't make many adjustments to diode parameters for power switch designs. Furthermore, different applications require different inductance and parasitic parameters, making adjustments impossible. Changing the application environment necessitates readjusting the existing test platform, which is relatively time-consuming. Current testing also requires the introduction of wires, which increases parasitic inductance and resistance in the circuit. Repeated wiring also accelerates aging of the PCB test board. Direct application replacement requires disassembly of the original application, a process that is often irreversible, and applications cannot be restored after disassembly testing. Different applications also have different PCB designs, presenting varying degrees of testing difficulty. Furthermore, the introduction of parasitic parameters can easily affect experimental results.

[0005] Therefore, how to achieve efficient and accurate testing of the dynamic characteristics of diodes under different application environments has become one of the problems that technical personnel in this field need to solve urgently. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a PCB circuit board, a diode characteristic testing system and a method for solving the problems of low efficiency and poor accuracy of diode characteristic testing in the prior art.

[0007] To achieve the above-mentioned and other related purposes, the present invention provides a diode characteristic testing system, which at least comprises:

[0008] Power switch tube, adjustable loop resistance, adjustable main loop inductance, adjustable power supply module, drive signal generation module, diode to be tested and adjustable diode junction capacitance;

[0009] One end of the power switch tube is connected to the positive electrode of the power module via the loop resistor and the main loop inductor in sequence, and the other end is connected to the negative electrode of the power module;

[0010] The driving signal generating module is connected to the driving end of the power switch tube and provides a driving signal for the power switch tube;

[0011] The cathode of the diode to be tested is connected to the positive electrode of the power module, and the anode is connected to the connection node of the loop resistor and the main loop inductor;

[0012] The diode junction capacitance is connected in parallel to both ends of the diode to be tested, and is used to adjust the size of the diode junction capacitance.

[0013] Optionally, the power supply module includes an energy storage capacitor, a switch and a first DC power supply; the switch and the first DC power supply are connected in series, the energy storage capacitor is connected in parallel at both ends of the series structure of the switch and the first DC power supply, and the energy storage capacitor provides power supply voltage for the diode characteristic test system.

[0014] More optionally, the power module further includes a current limiting resistor, and the current limiting resistor is connected in series in a series structure of the switch and the first DC power supply.

[0015] Optionally, the driving signal generating module is a discrete device driver or an integrated IC driver, which generates a driving signal with adjustable driving speed.

[0016] More optionally, the driving signal generating unit includes a signal generator, a first resistor, an NPN transistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first PNP transistor, a second PNP transistor, a diode and a second DC power supply;

[0017] The collector of the NPN transistor is connected to the second DC power supply via the first resistor, the emitter is grounded via the second resistor, and the base is connected to the output end of the signal generator via the third resistor;

[0018] The emitter of the first PNP transistor is connected to the second DC power supply, the collector is grounded via the fourth resistor, and the base is connected to the collector of the NPN transistor;

[0019] The anode of the diode is connected to the collector of the first PNP transistor via the fifth resistor, and the cathode is connected to the emitter of the second PNP transistor and outputs a driving signal;

[0020] The collector of the second PNP transistor is grounded, and the base is connected to the collector of the first PNP transistor.

[0021] Optionally, the driving signal generating unit is a push-pull topology drive, an optocoupler drive or a transformer drive.

[0022] To achieve the above-mentioned and other related purposes, the present invention further provides a PCB circuit board, the PCB circuit board comprising at least:

[0023] A substrate and the diode characteristic testing system arranged on the substrate.

[0024] Optionally, a hollow area is provided on the PCB circuit board, and the hollow area is used to set a current clamp to realize current detection.

[0025] To achieve the above-mentioned object and other related objects, the present invention further provides a diode characteristic testing method, which is implemented based on the above-mentioned diode characteristic testing system. The diode characteristic testing method at least includes:

[0026] Setting the power supply voltage and various parasitic parameters in the diode characteristic test system according to actual application conditions;

[0027] Providing a first drive pulse, the power switch tube is turned on, the power supply voltage charges the main circuit inductor, the first drive pulse ends, the power switch tube is turned off, the current in the main circuit inductor is freewheeling through the diode under test, a first current spike is generated when the diode under test is turned on, and the turn-on loss of the diode under test is obtained based on the first current spike and the voltage drop of the diode under test;

[0028] A second drive pulse is provided, the power switch tube is turned on, the reverse recovery current of the diode under test and the current of the main loop inductor are superimposed to generate a second current spike, and the turn-off loss of the diode under test is obtained based on the second current spike and the voltage drop of the diode under test.

[0029] To achieve the above-mentioned object and other related objects, the present invention further provides a diode characteristic testing method, which is implemented based on the above-mentioned diode characteristic testing system. The diode characteristic testing method at least includes:

[0030] Setting the power supply voltage and various parasitic parameters in the diode characteristic test system according to actual application conditions;

[0031] A first drive pulse is provided, the power switch tube is turned on, and the power supply voltage charges the main loop inductor. When the first drive pulse ends, the power switch tube is turned off, and the current on the main loop inductor is freewheeled through the diode to be tested to obtain the maximum surge current.

[0032] More optionally, the method for setting the power supply voltage in the diode characteristic test system includes: setting the first DC power supply to the required test voltage, turning on the switch, the first DC power supply charges the energy storage capacitor until the energy storage capacitor reaches the required voltage, turning off the switch, and the energy storage capacitor provides the power supply voltage.

[0033] More optionally, the current on the main loop inductor reaches a preset current by adjusting the on time of the first driving pulse.

[0034] More optionally, the size of the junction capacitance or parasitic inductance is adjusted to obtain a relationship between the junction capacitance or parasitic inductance and the limit of the diode to be measured.

[0035] As described above, the PCB circuit board, diode characteristics testing system and method of the present invention have the following beneficial effects:

[0036] 1. The PCB circuit board and diode characteristic testing system and method of the present invention can directly test the diode performance by measuring the parasitic parameters in the application and then adjusting them on the test board, which can greatly save testing time and cost; and the operation process is simple and easy.

[0037] 2. The PCB circuit board, diode characteristic testing system and method of the present invention can directly measure the line current without introducing wires through the PCB hollow design, preventing the introduction of parasitic inductance, additional impedance, etc. from affecting the experimental test results.

[0038] 3. The PCB circuit board and diode characteristic testing system and method of the present invention use energy storage capacitors to replace DC power supplies. When the pulse test time is very short, the capacitors can effectively maintain the voltage at the required level during the test, and the current can break through the current limit of the DC power supply and reach a higher current level.

[0039] 4. The PCB circuit board, diode characteristic testing system and method of the present invention control the switching speed of the MOSFET to adapt to the harsh conditions in different applications and have a wider range of applications.

[0040] 5. The PCB circuit board, diode characteristic testing system and method of the present invention can realize diode surge current testing, turn-on loss testing, turn-off loss testing, study the relationship between junction capacitance and diode limit, and study the influence of parasitic inductance on diode limit parameters, and are highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Shown is a structural schematic diagram of the diode characteristic testing system of the present invention.

[0042] Figure 2Shown is a waveform diagram of a diode switching loss test according to the present invention.

[0043] Component number description

[0044] 1 Diode Characteristics Test System

[0045] 11 Adjustable power module

[0046] 111 First DC Power Supply

[0047] 12. Drive signal generating unit

[0048] 121 Signal Generator

[0049] 122 Second DC power supply

[0050] Steps S11 to S13

[0051] Steps S21-S22 DETAILED DESCRIPTION

[0052] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0053] See also Figures 1 and 2 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0054] Example 1

[0055] like Figure 1 As shown, this embodiment provides a diode characteristic test system 1, and the diode characteristic test system 1 includes:

[0056] Power switch tube Q1, adjustable loop resistance Radj, adjustable main loop inductance Ladj, adjustable power supply module 11, drive signal generating module 12, diode to be tested Dtest and adjustable diode junction capacitance Cadj.

[0057] like Figure 1 As shown, the power supply module 11 provides power supply voltage for the diode characteristic testing system 1 .

[0058] Specifically, the power supply voltage provided by the power module 11 can be adjusted according to actual application needs. In this embodiment, after the test begins, the power module 11 supplies power to the diode characteristic test system 1 through an energy storage capacitor. In this embodiment, the power module 11 includes an energy storage capacitor Cpower, a switch SW, and a first DC power supply 111. As an example, the voltage of the first DC power supply 111 is set to 5V to 300V. The switch SW and the first DC power supply 111 are connected in series; as an example, the switch SW is connected to the positive electrode of the first DC power supply 111. The energy storage capacitor Cpower is connected in parallel to both ends of the series structure of the switch SW and the first DC power supply 111, that is, one end of the energy storage capacitor Cpower is connected to the switch SW, and the other end is connected to the first DC power supply 111; as an example, the upper plate of the energy storage capacitor Cpower is connected to the switch SW, and the lower plate is connected to the negative electrode of the first DC power supply 111. In order to prevent the peak of the charging current of the energy storage capacitor Cpower from being too high, the power supply module 11 also includes a current limiting resistor Rcl, which is connected in series in the series structure of the switch SW and the first DC power supply 111. As an example, one end of the current limiting resistor Rcl is connected to the negative electrode of the first DC power supply 111, and the other end is connected to the lower electrode of the energy storage capacitor Cpower.

[0059] It should be noted that any circuit that can provide the required power supply voltage is applicable to the present invention. The connection relationship between the various components in the power module of this embodiment can be adjusted according to actual needs and is not limited to this embodiment.

[0060] like Figure 1 As shown, one end of the power switch tube Q1 is connected to the positive electrode of the power module 11 via the loop resistor Radj and the main loop inductor Ladj in sequence, and the other end is connected to the negative electrode (ground) of the power module 11.

[0061] Specifically, in this embodiment, the power switch Q1 is an NMOS transistor, the source of which is grounded, and the drain of which is connected to the loop resistor Radj. In actual use, the type of the power switch can be selected as needed, including but not limited to an insulated gate bipolar transistor and a metal-oxide semiconductor field-effect transistor.

[0062] Specifically, the resistance of the loop resistor Radj is adjustable, and is used to simulate the impedance in an actual application circuit. The resistance of the loop resistor Radj can be adjusted according to the actual application scenario, which will not be described in detail here.

[0063] Specifically, the inductance value of the main loop inductor Ladj is adjustable, and the inductance value of the main loop inductor Ladj can be adjusted according to actual application scenarios, which will not be described in detail here.

[0064] like Figure 1 As shown, the driving signal generating module 12 is connected to the driving end of the power switch tube Q1 to provide a driving signal for the power switch tube Q1.

[0065] Specifically, in this embodiment, the driving speed of the driving signal output by the driving signal generating module 12 is adjustable; in actual use, if there is no requirement for the driving speed, the driving speed of the driving signal can be fixed. As an example, the driving signal generating unit 12 includes a signal generator 121, a first resistor R1, an NPN transistor Q2, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first PNP transistor Q3, a second PNP transistor Q4, a diode D, and a second DC power supply 122. The collector of the NPN transistor Q2 is connected to the second DC power supply 122 via the first resistor R1, the emitter is grounded via the second resistor R2, and the base is connected to the output end of the signal generator 121 via the third resistor R3. The emitter of the first PNP transistor Q3 is connected to the second DC power supply 122, the collector is grounded via the fourth resistor R4, and the base is connected to the collector of the NPN transistor Q2. The anode of the diode D is connected to the collector of the first PNP transistor Q3 via the fifth resistor R5, and the cathode is connected to the emitter of the second PNP transistor Q4, which outputs a drive signal. The collector of the second PNP transistor Q4 is grounded, and the base is connected to the collector of the first PNP transistor Q3. The resistance values ​​of the fourth resistor R4 and the fifth resistor R5 are adjustable. The fourth resistor R4 is used to control the shutdown speed, and the fifth resistor R5 is used to control the startup speed.

[0066] It should be noted that the circuit structure of the drive signal generating module 12 includes, but is not limited to, a push-pull topology drive, an optocoupler drive, or a transformer drive, and is not limited to this embodiment. The drive signal generating module 12 includes, but is not limited to, a discrete device drive or an integrated IC drive. Any circuit structure that can provide the drive signal required for testing is applicable to the present invention.

[0067] like Figure 1 As shown, the cathode of the diode to be tested Dtest is connected to the positive electrode of the power module 11, and the anode is connected to the connection node of the loop resistor Radj and the main loop inductor Ladj.

[0068] like Figure 1 As shown, the diode junction capacitance Cadj is connected in parallel to both ends of the diode to be tested Dtest, and is used to adjust the size of the diode junction capacitance.

[0069] Specifically, the capacitance value of the diode junction capacitance Cadj is adjustable, and the simulated junction capacitance value can be added / reduced according to experimental needs, so as to select a junction capacitance value that can effectively reduce the application current spike and / or switching process loss, providing data support for the subsequent development of new products.

[0070] Example 2

[0071] This embodiment provides a PCB circuit board, which includes: a substrate, and a diode characteristic test system arranged on the substrate; wherein the diode characteristic test system adopts the diode characteristic test system of Example 1, wherein the surface of the substrate is provided with a connecting circuit, and each device is arranged in a corresponding slot to realize a complete test system. The specific structure is not described here one by one.

[0072] Specifically, the PCB circuit board is provided with a hollowed-out area for positioning a current clamp to enable current detection. This allows the current flowing through the device to be measured without introducing new connecting wires, effectively avoiding the problems of increased parasitic parameters caused by the introduction of new connecting wires, and facilitating simple and easy operation. In actual use, the specific location of the hollowed-out area can be set according to the current to be measured, and detailed description is omitted here.

[0073] Specifically, the PCB circuit board is provided with reserved position holes, and the parasitic parameters in the circuit can be adjusted by adjusting the reserved position holes in the circuit.

[0074] Example 3

[0075] like Figure 1 and Figure 2 As shown, this embodiment provides a diode characteristic testing method, which is implemented based on the diode characteristic testing system 1 of the first embodiment. The diode characteristic testing method is used to obtain diode switching loss, including:

[0076] S11) Setting the power supply voltage and various parasitic parameters in the diode characteristic test system 1 according to actual application conditions.

[0077] Specifically, before the test, the first DC power supply 111 is set to the required test voltage, the switch SW is turned on, and the first DC power supply 111 charges the energy storage capacitor Cpower. After a preset time, the energy storage capacitor Cpower reaches the required voltage and accumulates an appropriate amount of charge, and the switch SW is turned off. To prevent the peak value of the energy storage capacitor Cpower from being too high during charging, the current is limited by the current limiting resistor Rcl. After the test begins, the energy storage capacitor Cpower provides the power supply voltage.

[0078] Specifically, the loop resistance Radj, the main loop inductance Ladj, the diode junction capacitance Cadj, the fourth resistor R4, and the fifth resistor R5 are adjusted according to actual application conditions. Furthermore, the parasitic parameters of the diode characteristic test system 1 are adjusted through the reserved holes according to the parasitic parameters in actual application. In this way, actual application scenarios are simulated.

[0079] It should be noted that there is no necessary logical relationship between the steps of setting the power supply voltage and the parasitic parameters. The power supply voltage can be set first, or the parasitic parameters can be set first. This is not limited to one by one.

[0080] S12) providing a first drive pulse, the power switch tube is turned on, the power supply voltage charges the main loop inductor, the first drive pulse ends, the power switch tube is turned off, the current in the main loop inductor is freewheeling through the diode under test, and a first current spike is generated at the moment of turning on the diode under test. The turn-on loss of the diode under test is obtained based on the first current spike and the voltage drop of the diode under test.

[0081] Specifically, the drive signal generating module 12 outputs a first drive pulse. When the first drive pulse is turned on, the power switch Q1 turns on the circuit through the driving action, the energy storage capacitor Cpower charges the main circuit inductor Ladj, and the current flows through the energy storage capacitor Cpower, the main circuit inductor Ladj, and the power switch Q1. As an example, the on-time of the first drive pulse is adjusted so that the current in the main circuit inductor Ladj reaches a desired preset current.

[0082] Specifically, when the current on the main circuit inductor Ladj reaches the preset current, the first drive pulse ends, the power switch tube Q1 is turned off, and the current in the main circuit inductor Ladj is freewheeling through the diode to be tested Dtest. A first current spike is generated at the turn-on moment of the diode to be tested Dtest. The first current spike oscillates with the diode junction capacitance Cadj and constitutes the turn-on loss of the diode to be tested Dtest together with the voltage drop of the diode to be tested Dtest, as shown in FIG. Figure 2 As an example, the integral of the product of the first current peak and the voltage drop of the diode to be tested Dtest is the turn-on loss.

[0083] S13) providing a second drive pulse, the power switch tube is turned on, the reverse recovery current of the diode under test and the current of the main loop inductor are superimposed to generate a second current spike, and the turn-off loss of the diode under test is obtained based on the second current spike and the voltage drop of the diode under test.

[0084] Specifically, the turn-off process of the power switch tube Q1 continues until the oscillation disappears and the current stabilizes (which takes about several microseconds), and then the drive signal generating module 12 outputs a second drive pulse. When the second drive pulse is turned on, the reverse recovery current of the diode to be tested Dtest is superimposed on the inductor current to generate a second current spike. The second peak current oscillates with the diode junction capacitance Cadj and the junction capacitance of the power switch tube Q1, and together with the voltage drop of the diode to be tested Dtest, constitutes the turn-off loss of the diode to be tested Dtest, as shown in FIG. Figure 2 As an example, the integral of the product of the second current peak and the voltage drop of the diode to be tested Dtest is the turn-off loss.

[0085] It should be noted that the effect of junction capacitance on switching loss can be measured by adjusting the junction capacitance, and the relationship between junction capacitance and the maximum switching loss of the diode under test can be studied. The effect of parasitic inductance on switching loss can also be measured by adjusting the parasitic inductance, and the relationship between parasitic inductance and the maximum switching loss of the diode under test can be studied.

[0086] Example 4

[0087] like Figure 1 As shown, this embodiment provides a diode characteristic testing method, which is implemented based on the diode characteristic testing system 1 of the first embodiment. The diode characteristic testing method is used to obtain the maximum surge current of the diode, including:

[0088] S21) Setting the power supply voltage and various parasitic parameters in the diode characteristic test system according to actual application conditions.

[0089] Specifically, the specific method of this step can be referred to step S11) of embodiment 3, which will not be described in detail here.

[0090] S22) providing a first drive pulse, the power switch tube is turned on, the power supply voltage charges the main loop inductor, and when the first drive pulse ends, the power switch tube is turned off, the current on the main loop inductor is continuously flowing through the diode to be tested, and the maximum surge current is obtained.

[0091] Specifically, the drive signal generating module 12 outputs a first drive pulse, and controls the current on the main circuit inductor Ladj by the on time of the first drive pulse. When the current on the main circuit inductor Ladj reaches a preset current, the first drive pulse ends, and the current in the main circuit inductor Ladj is continued through the diode to be tested Dtest, and the maximum surge current is obtained by measurement.

[0092] It should be noted that the effect of junction capacitance on inrush current can be measured by adjusting the size of the junction capacitance, and the relationship between junction capacitance and the limiting inrush current of the diode under test can be studied. The effect of parasitic inductance on inrush current can also be measured by adjusting the size of the parasitic inductance, and the relationship between parasitic inductance and the limiting inrush current of the diode under test can be studied.

[0093] The present invention measures the parasitic parameters in the application and then adjusts them on the test board, so that the diode performance can be directly tested without rebuilding the test platform, which can greatly save the test time and cost; and the operation process is simple and easy. The present invention can accurately restore the actual application scenario and has high test accuracy. The present invention adopts a current clamp to measure the current through the PCB hollow design, and can directly measure the line current without introducing a wire, preventing the introduction of parasitic inductance, additional impedance, etc. from affecting the experimental test results. The present invention uses a storage capacitor to replace the DC power supply. When the pulse test time is very short, the capacitor can effectively maintain the voltage at the required level during the test, and the current can break through the current limit of the DC power supply to achieve a higher current level. The present invention controls the switching speed of the MOSFET to adjust to the harsh conditions in different applications, and has a wider range of applications. The present invention can realize diode surge current testing, turn-on loss testing, turn-off loss testing, study the relationship between the junction capacitance size and the diode limit, and study the influence of parasitic inductance on the diode limit parameters, and has strong practicality.

[0094] In summary, the present invention provides a PCB circuit board and diode characteristic testing system and method, including: a power switch tube, an adjustable loop resistor, an adjustable main loop inductor, an adjustable power supply module, a drive signal generating module, a diode to be tested, and an adjustable diode junction capacitance; one end of the power switch tube is connected to the positive electrode of the power supply module via the loop resistor and the main loop inductor in sequence, and the other end is connected to the negative electrode of the power supply module; the drive signal generating module is connected to the drive end of the power switch tube to provide a drive signal for the power switch tube; the cathode of the diode to be tested is connected to the positive electrode of the power supply module, and the anode is connected to the connection node of the loop resistor and the main loop inductor; the diode junction capacitance is connected in parallel to the two ends of the diode to be tested to adjust the size of the diode junction capacitance. The PCB circuit board, diode characteristic testing system, and method of the present invention can greatly save testing time and cost, and the operation process is simple and easy. It prevents the introduction of parasitic inductance, additional impedance, and the like that affect experimental test results, and has high accuracy. It can break through the current limit of the DC power supply and achieve higher current levels. It can adapt to the harsh conditions in different applications and has a wider range of applications. It can implement diode surge current testing, turn-on loss testing, turn-off loss testing, study the relationship between junction capacitance and diode limit, and study the influence of parasitic inductance on diode limit parameters, and has strong practicality. Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial application value.

[0095] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A diode characteristic test system, characterized in that: The diode characteristic testing system at least includes: Power switch tube, adjustable loop resistance, adjustable main loop inductance, adjustable power supply module, drive signal generation module, diode to be tested and adjustable diode junction capacitance; One end of the power switch tube is connected to the positive electrode of the power module via the loop resistor and the main loop inductor in sequence, and the other end is connected to the negative electrode of the power module; The drive signal generating module is connected to the driving end of the power switch tube and provides a drive signal for the power switch tube; wherein the drive signal generating unit includes a signal generator, a first resistor, an NPN transistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first PNP transistor, a second PNP transistor, a diode and a second DC power supply; the collector of the NPN transistor is connected to the second DC power supply via the first resistor, the emitter is grounded via the second resistor, and the base is connected to the output end of the signal generator via the third resistor; the emitter of the first PNP transistor is connected to the second DC power supply, the collector is grounded via the fourth resistor, and the base is connected to the collector of the NPN transistor; the anode of the diode is connected to the collector of the first PNP transistor via the fifth resistor, the cathode is connected to the emitter of the second PNP transistor and outputs the drive signal; the collector of the second PNP transistor is grounded, and the base is connected to the collector of the first PNP transistor; the resistance values ​​of the fourth resistor and the fifth resistor are adjustable; The cathode of the diode to be tested is connected to the positive electrode of the power module, and the anode is connected to the connection node of the loop resistor and the main loop inductor; The diode junction capacitance is connected in parallel to both ends of the diode to be tested, and is used to adjust the size of the diode junction capacitance.

2. The diode characteristic test system according to claim 1, wherein: The power supply module includes an energy storage capacitor, a switch and a first DC power supply; the switch and the first DC power supply are connected in series, the energy storage capacitor is connected in parallel at both ends of the series structure of the switch and the first DC power supply, and the energy storage capacitor provides power supply voltage for the diode characteristic testing system.

3. The diode characteristic test system according to claim 2, wherein: The power module further includes a current limiting resistor, which is connected in series in a series structure of the switch and the first DC power supply.

4. The diode characteristic test system according to claim 1, wherein: The driving signal generating module is a discrete device driver or an integrated IC driver, and generates a driving signal with adjustable driving speed.

5. The diode characteristic test system according to claim 1, wherein: The driving signal generating unit is a push-pull topology drive, an optocoupler drive or a transformer drive.

6. A PCB circuit board, characterized in that: The PCB circuit board at least includes: A substrate, and a diode characteristic testing system according to any one of claims 1 to 5 arranged on the substrate.

7. The PCB circuit board according to claim 6, characterized in that: A hollow area is provided on the PCB circuit board, and the hollow area is used to set a current clamp to realize current detection.

8. A diode characteristic testing method, implemented based on the diode characteristic testing system according to any one of claims 1 to 5, characterized in that: The diode characteristic testing method at least includes: Setting the power supply voltage and various parasitic parameters in the diode characteristic test system according to actual application conditions; Providing a first drive pulse, the power switch tube is turned on, the power supply voltage charges the main circuit inductor, the first drive pulse ends, the power switch tube is turned off, the current in the main circuit inductor is freewheeling through the diode under test, a first current spike is generated when the diode under test is turned on, and the turn-on loss of the diode under test is obtained based on the first current spike and the voltage drop of the diode under test; A second drive pulse is provided, the power switch tube is turned on, the reverse recovery current of the diode under test and the current of the main loop inductor are superimposed to generate a second current spike, and the turn-off loss of the diode under test is obtained based on the second current spike and the voltage drop of the diode under test.

9. A diode characteristic testing method, implemented based on the diode characteristic testing system according to any one of claims 1 to 5, characterized in that: The diode characteristic testing method at least includes: Setting the power supply voltage and various parasitic parameters in the diode characteristic test system according to actual application conditions; A first drive pulse is provided, the power switch tube is turned on, and the power supply voltage charges the main loop inductor. When the first drive pulse ends, the power switch tube is turned off, and the current on the main loop inductor is freewheeled through the diode to be tested to obtain the maximum surge current.

10. The diode characteristic testing method according to claim 8 or 9, characterized in that: The method for setting the power supply voltage in the diode characteristic test system includes: setting the first DC power supply to the required test voltage, turning on the switch, the first DC power supply charges the energy storage capacitor until the energy storage capacitor reaches the required voltage, turning off the switch, and the energy storage capacitor provides the power supply voltage.

11. The diode characteristic testing method according to claim 8 or 9, characterized in that: The current on the main loop inductor reaches a preset current by adjusting the on time of the first driving pulse.

12. The diode characteristic testing method according to claim 8 or 9, characterized in that: The size of the junction capacitance or parasitic inductance is adjusted to obtain the relationship between the junction capacitance or parasitic inductance and the limit of the diode to be measured.

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