CN115407171A - PCB (printed circuit board), and diode characteristic testing system and method - Google Patents

Abstract

The present invention provides a PCB circuit board and a diode characteristic testing system and method, including: a power switch tube, an adjustable loop resistance, an adjustable main loop inductance, an adjustable power supply module, a drive signal generation module, a diode to be tested and Adjustable diode junction capacitance; one end of the power switch tube is connected to the positive pole of the power module through the loop resistance and the main loop inductance in turn, and the other end is connected to the negative pole of the power module; the driving signal generation module is connected to the driving end of the power switch tube, which is a power switch The tube provides the driving signal; the cathode of the diode to be tested is connected to the anode of the power module, and the connection node of the loop resistance of the anode and the main loop inductance; the diode junction capacitance is connected in parallel to both ends of the diode to be tested to adjust the size of the diode junction capacitance. The invention saves test time and cost, has simple and easy operation process, high test result accuracy, wider application range and strong practicability.

Description

PCB circuit board, diode characteristic testing system and method

technical field

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

Background technique

In the field of 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) for output rectification. Therefore, it is necessary to test the performance of the diode.

For the test in the application, usually use the test platform or replace the corresponding Schottky diode on the formed product to test the working condition of the diode in the application and judge whether the diode of a certain specification can be replaced accordingly . For the research and development of new diode products, simply looking at the static parameters of the device, such as forward voltage drop, reverse leakage current, etc., cannot clearly reflect the dynamic performance of the device in a specific application, and also needs to rely on the specific application environment.

The existing test platform is designed for the power switch tube, and the diode parameters have not been adjusted too much, and in the face of different types of applications, the corresponding inductance and parasitic parameters are also different, and it is impossible to adjust for different applications. To change the application environment, it is necessary to readjust the existing test platform, which takes a relatively long time; and the current test needs to introduce wires, which will increase the parasitic inductance and resistance in the circuit, and repeated wiring will also accelerate the aging of the PCB test board. However, the method of directly replacing the application needs to disassemble the original application in operation. There will be different degrees of difficulty in the circuit, and it is easy to introduce lines, and the parasitic parameters introduced will also affect the experimental results to varying degrees.

Therefore, how to efficiently and accurately test the dynamic characteristics of diodes under different application environments has become one of the problems to be solved urgently by those skilled in the art.

Contents of the invention

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a PCB circuit board, a diode characteristic testing system and method, which are used to solve the problems of low efficiency and poor accuracy of diode characteristic testing in the prior art.

In order to achieve the above purpose and other related purposes, the present invention provides a diode characteristic test system, the diode characteristic test system at least includes:

Power switching 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 sequentially connected to the positive pole of the power module via the loop resistance and the main loop inductance, and the other end is connected to the negative pole of the power module;

The driving signal generation module is connected to the driving 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 anode of the power module, and the anode is connected to the connection node between the loop resistance and the main loop inductance;

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

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, and the energy storage capacitor is connected in parallel between the switch and the first DC power supply. The two ends of the series structure of the current power supply, the energy storage capacitor provides the power supply voltage for the diode characteristic testing system.

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

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

More optionally, 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 source;

The collector of the NPN transistor is connected to the second DC power supply through the first resistor, the emitter is grounded through the second resistor, and the base is connected to the output terminal of the signal generator through the third resistor;

The emitter of the first PNP transistor is connected to the second DC power supply, the collector is grounded through 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 through the fifth resistor, and the cathode is connected to the emitter of the second PNP transistor to output a driving signal;

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

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

In order to achieve the above purpose and other related purposes, the present invention also provides a PCB circuit board, and the PCB circuit board at least includes:

A substrate, and the above-mentioned diode characteristic testing system arranged on the substrate.

Optionally, a hollow area is provided on the PCB, and the hollow area is used for setting a current clip to realize current detection.

In order to achieve the above purpose and other related purposes, the present invention also provides a diode characteristic test method, which is realized based on the above diode characteristic test system, and the diode characteristic test method at least includes:

Setting the power supply voltage and various parasitic parameters in the diode characteristic testing system according to actual application conditions;

The first drive pulse is provided, the power switch is turned on, the power supply voltage is charged to the main loop inductance, the first drive pulse ends, the power switch is turned off, and the current on the main loop inductance passes through the The freewheeling of the diode to be tested, the first current peak is generated at the turn-on moment of the diode to be tested, and the turn-on loss of the diode to be tested is obtained based on the first current peak and the voltage drop of the diode to be tested;

A second drive pulse is provided, the power switch is turned on, the reverse recovery current of the diode to be tested is superimposed on the current of the main loop inductance to generate a second current peak, based on the second current peak and the to-be-tested The voltage drop of the diode under test is used to obtain the turn-off loss of the diode under test.

In order to achieve the above purpose and other related purposes, the present invention also provides a diode characteristic test method, which is realized based on the above diode characteristic test system, and the diode characteristic test method at least includes:

Setting the power supply voltage and various parasitic parameters in the diode characteristic testing system according to actual application conditions;

The first drive pulse is provided, the power switch is turned on, the power supply voltage is charged to the main loop inductance, the first drive pulse ends, the power switch is turned off, and the current on the main loop inductance passes through the The freewheeling current of the diode to be tested is obtained to obtain the maximum value of the surge current.

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

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

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 tested.

As mentioned above, the PCB circuit board and diode characteristic testing system and method of the present invention have the following beneficial effects:

1. The PCB circuit board and diode characteristic testing system and method of the present invention adjust the parasitic parameters on the test board after measuring the parasitic parameters in the application, so as to directly test the diode performance, which can greatly save the test time and cost; and the operation process Simple and easy.

2. The PCB circuit board and 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.

3. The PCB circuit board and diode characteristic testing system and method of the present invention replace the DC power supply with energy storage capacitors. When the pulse test time is very short, the capacitor can effectively maintain the voltage during the test at the required level, and the current can be Break through the current limit of the DC power supply and reach higher current levels.

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

5. The PCB circuit board and diode characteristic testing system and method of the present invention can realize diode surge current test, turn-on loss test, turn-off loss test, study the relationship between junction capacitance and diode limit, and study the effect of parasitic inductance on diode limit parameters Influence, strong practicability.

Description of drawings

FIG. 1 is a schematic structural diagram of a diode characteristic testing system of the present invention.

FIG. 2 is a schematic waveform diagram of the diode switching loss test of the present invention.

Component designation description

1 Diode characteristic test system

11 adjustable power modules

111 The first DC power supply

12 drive signal generation unit

121 signal generator

122 Second DC power supply

S11～S13 steps

S21～S22 steps

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figures 1 to 2. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

Embodiment one

As shown in FIG. 1 , the present embodiment provides a diode characteristic testing system 1, and the diode characteristic testing system 1 includes:

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.

As shown in FIG. 1 , the power supply module 11 provides a power supply voltage for the diode characteristic testing system 1 .

Specifically, the value of the power supply voltage provided by the power supply module 11 can be adjusted according to actual application requirements. In this embodiment, the power supply module 11 supplies power to the diode characteristic testing system 1 through the energy storage capacitor after the test starts. 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-300V. The switch SW and the first DC power source 111 are connected in series; as an example, the switch SW is connected to the positive pole of the first DC power source 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. 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 pole 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 module 11 further includes a current limiting resistor Rcl, and the current limiting resistor Rcl is connected in series with the switch SW and the first DC power supply 111 in series. In the structure, as an example, one end of the current limiting resistor Rcl is connected to the negative pole of the first DC power supply 111, and the other end is connected to the lower electrode of the energy storage capacitor Cpower.

It should be noted that any circuit that can provide the required power supply voltage is applicable to the present invention, and the connection relationship of each device in the power module of this embodiment can be adjusted according to actual needs, and is not limited to this embodiment.

As shown in Figure 1, one end of the power switch tube Q1 is connected to the positive pole of the power module 11 via the loop resistance Radj and the main loop inductance Ladj in sequence, and the other end is connected to the negative pole (ground) of the power module 11 .

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

Specifically, the resistance value of the loop resistance Radj is adjustable, which is used to simulate the impedance in the actual application circuit, and the resistance value of the loop resistance Radj can be adjusted according to the actual application scene, and details will not be repeated here.

Specifically, the inductance value of the main loop inductance Ladj is adjustable, and the inductance value of the main loop inductance Ladj can be adjusted according to actual application scenarios, which will not be repeated here.

As shown in FIG. 1 , the driving signal generating module 12 is connected to the driving end of the power switching transistor Q1 to provide a driving signal for the power switching transistor Q1 .

Specifically, in this embodiment, the driving speed of the driving signal output by the driving signal generation 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 drive 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 , the second PNP transistor Q4 , the diode D and the second DC power supply 122 . The collector of the NPN transistor Q2 is connected to the second DC power supply 122 through the first resistor R1, the emitter is grounded through the second resistor R2, and the base is connected to the signal generator through the third resistor R3 121 output. The emitter of the first PNP transistor Q3 is connected to the second DC power supply 122 , the collector is grounded through 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 through the fifth resistor R5, and the cathode is connected to the emitter of the second PNP transistor Q4 to output a driving 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. Wherein, the resistance values of the fourth resistor R4 and the fifth resistor R5 are adjustable, the fourth resistor R4 is used to control the turn-off speed, and the fifth resistor R5 is used to control the turn-on speed.

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

As shown in FIG. 1 , the cathode of the diode to be tested Dtest is connected to the anode of the power module 11 , and the anode is connected to the connection node of the loop resistance Radj and the main loop inductance Ladj.

As shown in FIG. 1 , the diode junction capacitance Cadj is connected in parallel with both ends of the diode to be tested Dtest for adjusting the size of the diode junction capacitance.

Specifically, the capacitance value of the diode junction capacitance Cadj is adjustable, and the analog 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 peak and/or the switching process loss, Provide data support for later development of new products.

Embodiment two

This embodiment provides a PCB circuit board, the PCB circuit board includes: a substrate, and a diode characteristic testing system arranged on the substrate; wherein, the diode characteristic testing system adopts the diode characteristic testing system of Embodiment 1, The surface of the substrate is provided with connecting lines, and each device is arranged in a corresponding slot to realize a complete test system, and the specific structure will not be repeated here.

Specifically, a hollow area is provided on the PCB circuit board, and the hollow area is used for setting a current clamp to realize current detection. Therefore, the current flowing through the device can be tested without introducing new connecting wires, which effectively avoids problems such as the increase of parasitic parameters caused by introducing new connecting wires, and is convenient and easy to operate. In actual use, the specific position of the hollowed out area can be set according to the current to be measured, and will not be described here.

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.

Embodiment three

As shown in Figures 1 and 2, this embodiment provides a diode characteristic testing method, which is implemented based on the diode characteristic testing system 1 of Embodiment 1. The diode characteristic testing method is used to obtain diode switching losses, including:

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

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 period of time, the energy storage capacitor Cpower reaches the required voltage and accumulates an appropriate amount of charge, and the switch SW is turned off. In order to prevent the peak of the energy storage capacitor Cpower from being too high when charging, the current is limited by the current limiting resistor Rcl. After the test starts, the energy storage capacitor Cpower provides the power supply voltage.

Specifically, adjust the size of the loop resistance Radj, the main loop inductance Ladj, the diode junction capacitance Cadj, the fourth resistor R4, and the fifth resistor R5 according to the actual application; and according to the actual application The parasitic parameter adjusts the parasitic parameter of the diode characteristic testing system 1 through the reserved position hole. In this way, the actual application scenario is simulated.

It should be noted that there is no necessary logical relationship between the steps of setting the power supply voltage and various parasitic parameters. The power supply voltage or the parasitic parameters can be set first, which are not limited here.

S12) The first drive pulse is provided, the power switch is turned on, the power supply voltage is charged to the main loop inductance, the first drive pulse ends, the power switch is turned off, and the current on the main loop inductance Through the freewheeling of the diode under test, a first current peak is generated at the turn-on moment of the diode under test, and the turn-on loss of the diode under test is obtained based on the first current peak and the voltage drop of the diode under test.

Specifically, the driving signal generation module 12 outputs a first driving pulse. When the first driving pulse is turned on, the power switch tube Q1 turns on the circuit through driving, and the energy storage capacitor Cpower is the main circuit inductance Ladj is charged, and the current flows through the energy storage capacitor Cpower, the main loop inductance Ladj and the power switch tube Q1. As an example, the current on the main loop inductance Ladj reaches a required preset current by adjusting the on-time of the first driving pulse.

Specifically, when the current on the main loop inductance Ladj reaches a preset current, the first driving pulse ends, the power switch tube Q1 is turned off, and the current in the main loop inductance Ladj passes through the The diode Dtest performs freewheeling, and a first current peak will be generated at the turn-on moment of the diode Dtest to be tested, and the first current peak will oscillate with the diode junction capacitance Cadj, and form a voltage drop with the diode Dtest to be tested. The turn-on loss of the diode under test Dtest is shown in FIG. 2 . As an example, the integral of the product of the first current peak and the voltage drop of the diode under test Dtest is the turn-on loss.

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 inductance are superimposed to generate a second current peak, based on the second current peak and the The voltage drop of the diode under test is used to obtain the turn-off loss of the diode under test.

Specifically, the turn-off process of the power switch tube Q1 lasts until the oscillation disappears and the current stabilizes (it may take several microseconds), and then the driving signal generation module 12 outputs a second driving pulse. When the second driving 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 peak, and the second peak current oscillates with the diode junction capacitance Cadj and the junction capacitance of the power switch Q1, and Together with the voltage drop of the diode under test Dtest, the turn-off loss of the diode under test Dtest is formed, as shown in FIG. 2 . As an example, the integral of the product of the second current peak and the voltage drop of the diode under test Dtest is the turn-off loss.

It should be noted that the influence of the junction capacitance on the switching loss can also be obtained by adjusting the size of the junction capacitance, and the relationship between the junction capacitance and the limit switching loss of the diode under test can be studied. The influence of the parasitic inductance on the switching loss can also be obtained by adjusting the size of the parasitic inductance, and the relationship between the parasitic inductance and the limit switching loss of the diode under test can be studied.

Embodiment four

As shown in FIG. 1 , this embodiment provides a diode characteristic test method, which is implemented based on the diode characteristic test system 1 of Embodiment 1. The diode characteristic test method is used to obtain the maximum value of the surge current of the diode, including:

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

Specifically, for the specific method of this step, refer to step S11) of Embodiment 3, which will not be repeated here.

S22) A first drive pulse is provided, the power switch is turned on, the power supply voltage is charged to the main loop inductance, the first drive pulse ends, the power switch is turned off, and the current on the main loop inductance By freewheeling the diode under test, the maximum value of the surge current is obtained.

Specifically, the drive signal generation module 12 outputs a first drive pulse, and controls the magnitude of the current on the main loop inductance Ladj through the turn-on time of the first drive pulse. When the current on the main loop inductance Ladj reaches a predetermined When the current is set, the first driving pulse ends, the current in the main loop inductance Ladj continues to flow through the diode under test Dtest, and the maximum value of the surge current is obtained through measurement.

It should be noted that the influence of the junction capacitance on the surge current can also be obtained by adjusting the size of the junction capacitance, and the relationship between the junction capacitance and the limit surge current of the diode under test can be studied. The influence of the parasitic inductance on the surge current can also be obtained by adjusting the size of the parasitic inductance, and the relationship between the parasitic inductance and the limit surge current of the diode under test can be studied.

The invention measures the parasitic parameters in the application and adjusts them on the test board, so that the performance of the diode 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 invention can accurately restore the actual application scene, and the test accuracy is high. The present invention adopts the current clamp to measure the current through the hollow design of the PCB, and can directly measure the line current without introducing wires, preventing the introduction of parasitic inductance, additional impedance, etc. from affecting the experimental test results. The present invention replaces the DC power supply with an energy storage capacitor. When the pulse test time is very short, the capacitor can effectively maintain the voltage during the test at the required level, and the current can break through the current limit of the DC power supply and reach a higher current level. . The invention controls the switching speed of the MOSFET to adapt to harsh conditions in different applications for adjustment, and has a wider application range. The invention can realize diode surge current test, turn-on loss test, turn-off loss test, study the relationship between junction capacitance and diode limit, study the influence of parasitic inductance on diode limit parameters, and has strong practicability.

In summary, the present invention provides a PCB circuit board, a diode characteristic testing system and method, including: a power switch tube, an adjustable loop resistance, an adjustable main loop inductance, an adjustable power supply module, and a drive signal generation module , the diode to be tested and the adjustable diode junction capacitance; one end of the power switch tube is connected to the positive pole of the power module via the loop resistance and the main loop inductance in turn, and the other end is connected to the negative pole of the power module; The driving signal generation module is connected to the driving 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 pole of the power module, and the anode is connected to the loop resistance and the A connection node of the main loop inductance; the diode junction capacitance is connected in parallel with both ends of the diode to be tested, and is used to adjust the size of the diode junction capacitance. The PCB circuit board and diode characteristic test system and method of the present invention can greatly save test time and cost, and the operation process is simple and easy; it prevents the introduction of parasitic inductance, additional impedance, etc. from affecting the experimental test results, and has high accuracy; it can break through the DC power supply The current limit can reach a higher current level; it can be adjusted to adapt to the harsh conditions in different applications, and the application range is wider; it can realize diode surge current test, turn-on loss test, turn-off loss test, and research on junction capacitance and diode It is practical to study the relationship between the limit and the influence of parasitic inductance on the limit parameters of the diode. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (13)

1. a diode characteristic testing system, is characterized in that, described diode characteristic testing system comprises at least: Power switching 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 sequentially connected to the positive pole of the power module via the loop resistance and the main loop inductance, and the other end is connected to the negative pole of the power module; The driving signal generation module is connected to the driving 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 anode of the power module, and the anode is connected to the connection node between the loop resistance and the main loop inductance; The diode junction capacitance is connected in parallel with both ends of the diode to be tested, and is used to adjust the size of the diode junction capacitance. 2. The diode characteristic testing system according to claim 1, characterized in that: 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, and the An energy storage capacitor is connected in parallel to both ends of the series structure of the switch and the first DC power supply, and the energy storage capacitor provides a power supply voltage for the diode characteristic testing system. 3. The diode characteristic testing system according to claim 2, characterized in that: the power module further comprises a current-limiting resistor, and the current-limiting resistor is connected in series in the series structure of the switch and the first DC power supply . 4. The diode characteristic testing system according to claim 1, wherein the driving signal generating module is driven by a discrete device or an integrated IC, and generates a driving signal with an adjustable driving speed. 5. The diode characteristic testing system according to claim 1 or 4, characterized in that: the drive signal generating unit comprises a signal generator, a first resistor, an NPN triode, 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 through the first resistor, the emitter is grounded through the second resistor, and the base is connected to the output terminal of the signal generator through the third resistor; The emitter of the first PNP transistor is connected to the second DC power supply, the collector is grounded through 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 through the fifth resistor, and the cathode is connected to the emitter of the second PNP transistor to output a driving signal; The collector of the second PNP transistor is grounded, and the base is connected to the collector of the first PNP transistor. 6 . The diode characteristic testing system according to claim 1 , wherein the driving signal generating unit is a push-pull topology driving, an optocoupler driving or a transformer driving. 7. A kind of PCB circuit board, is characterized in that, described PCB circuit board comprises at least: A substrate, and the diode characteristic testing system according to any one of claims 1-6 arranged on the substrate. 8 . The PCB circuit board according to claim 7 , wherein a hollow area is set on the PCB circuit board, and the hollow area is used for setting a current clamp to realize current detection. 9. A diode characteristic test method, realized based on the diode characteristic test system as claimed in any one of claims 1-6, wherein the diode characteristic test method at least comprises: Setting the power supply voltage and various parasitic parameters in the diode characteristic testing system according to actual application conditions; The first drive pulse is provided, the power switch is turned on, the power supply voltage is charged to the main loop inductance, the first drive pulse ends, the power switch is turned off, and the current on the main loop inductance passes through the The freewheeling of the diode to be tested, the first current peak is generated at the turn-on moment of the diode to be tested, and the turn-on loss of the diode to be tested is obtained based on the first current peak and the voltage drop of the diode to be tested; A second drive pulse is provided, the power switch is turned on, the reverse recovery current of the diode to be tested is superimposed on the current of the main loop inductance to generate a second current peak, based on the second current peak and the to-be-tested The voltage drop of the diode under test is used to obtain the turn-off loss of the diode under test. 10. A diode characteristic test method, realized based on the diode characteristic test system according to any one of claims 1-6, characterized in that, the diode characteristic test method at least comprises: Setting the power supply voltage and various parasitic parameters in the diode characteristic testing system according to actual application conditions; The first drive pulse is provided, the power switch is turned on, the power supply voltage is charged to the main loop inductance, the first drive pulse ends, the power switch is turned off, and the current on the main loop inductance passes through the The freewheeling current of the diode to be tested is obtained to obtain the maximum value of the surge current. 11. The diode characteristic testing method according to claim 9 or 10, characterized in that: the method for setting the power supply voltage in the diode characteristic testing system comprises: setting the first direct current power supply to a required test voltage, leading When the switch is turned on, the first DC power supply charges the energy storage capacitor until the energy storage capacitor reaches a required voltage; when the switch is turned off, the energy storage capacitor provides the power supply voltage. 12. The diode characteristic testing method according to claim 9 or 10, wherein the current on the main loop inductance reaches a preset current by adjusting the turn-on time of the first driving pulse. 13. The diode characteristic test method according to claim 9 or 10, 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 tested.

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