Transistor testing device
By designing a transistor testing device containing multi-stage protection module, the problem of transistor and equipment damage in the existing test solutions is solved, and safety and accuracy during the test process are achieved.
Patent Information
- Application Number
- CN202411984886.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-05-13
AI Technical Summary
The existing gallium nitride transistor testing schemes are prone to damage to transistors and test equipment during device testing.
A transistor testing device is designed, including a drive protection module, an oscilloscope, a clamp protection module, a first-level protection module and a second-level protection module. Through the coordinated work of these modules, the on-off of the transistors to be tested is controlled to prevent excessive current or voltage from causing damage to the equipment.
It effectively protects the transistors, oscilloscopes and other modules in the test device, avoids equipment damage during the test process, and ensures the safety and accuracy of the test.
Smart Images
Figure CN119986293A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of testing technology, and in particular to a transistor testing device. Background Art
[0002] Gallium nitride transistors are popular in the field of power electronics due to their advantages of high power and low loss.
[0003] During the design process, the change of dynamic on-resistance of GaN transistors is one of the more important issues affecting the research and development of GaN transistors. In order to accurately measure the change of dynamic on-resistance under different stress conditions and continuously improve the problem of dynamic resistance degradation based on analysis results, many dynamic on-resistance test solutions have emerged.
[0004] However, current testing solutions can easily cause damage to GaN transistors and testing equipment during device testing. Summary of the invention
[0005] The embodiment of the present disclosure provides a transistor testing device that can be used in a device testing process. The technical solution is as follows:
[0006] In one aspect, a transistor testing device is provided, the transistor testing device comprising:
[0007] A driving protection module, electrically connected to the control electrode of the transistor to be tested, and used to control the conduction of the transistor to be tested, and control the transistor to be tested to be turned off when the loop current is greater than a first set value;
[0008] An oscilloscope, electrically connected to the first electrode and the second electrode of the transistor to be tested, and used to detect the dynamic on-resistance of the transistor to be tested;
[0009] A clamping protection module, electrically connected to the first electrode of the transistor to be tested and the oscilloscope, and used for cutting off the circuit between the oscilloscope and the transistor to be tested when the transistor to be tested fails;
[0010] A primary protection module, electrically connected to the first electrode and the second electrode of the transistor to be tested, and used to prevent the clamping protection module from being impacted by a large current;
[0011] The secondary protection module is electrically connected between the oscilloscope and the clamp protection module, and is used to prevent the oscilloscope from being subjected to a large voltage shock.
[0012] The transistor to be tested is also referred to as the device under test (DUT).
[0013] The dynamic on-resistance refers to the resistance between the drain and source when the device is in the fully on state.
[0014] During testing, the disclosed embodiments apply different stresses to the transistor, and then detect the resistance value between the drain and source of the transistor under each stress when the transistor is turned on to a fully on state, thereby providing data support for the research and development and optimization of the transistor under test.
[0015] In the embodiments of the present disclosure, the oscilloscope may be any type of oscilloscope with a bandwidth of more than 350 MHz, so as to be able to detect the dynamic conductive resistance of the transistor to be tested.
[0016] Optionally, in addition to the above modules, the transistor testing device further comprises a power supply module, which is electrically connected to two ends of the transistor to be tested and is used to provide power to the transistor to be tested to form a loop.
[0017] Among them, the power module can be an IT6500 series wide-range high-power programmable DC power supply.
[0018] Optionally, the transistor testing device further includes a resistor R11 and a resistor R12, and the resistor R11 and the resistor R12 are connected in series with the transistor to be tested.
[0019] The resistor R11 and the resistor R12 are respectively arranged on two sides of the transistor to be tested.
[0020] One end of the resistor R11 connected to the power source 100 is grounded.
[0021] Among them, R11 can be a 50mΩ high-precision sampling resistor, and R12 can be a 400Ω load resistor.
[0022] When the driving protection module controls the transistor to be tested to be turned off, it is triggered by the size of the loop current. The size of the loop current is the current of the loop composed of the power module, the transistor to be tested, the resistor R11 and the resistor R12.
[0023] Optionally, the driving protection module is an SI8285 type isolated gate driver.
[0024] Optionally, the clamping protection module includes an isolated gate driver and a first transistor, the first electrode of the first transistor is electrically connected to the first electrode of the transistor to be tested, the second electrode of the first transistor is electrically connected to the secondary protection module, and the control electrode of the first transistor is electrically connected to the isolated gate driver.
[0025] Optionally, the isolated gate driver is used to control the first transistor to be turned off when the gate-source leakage current of the first transistor exceeds a second set value.
[0026] Optionally, the isolated gate driver is an SI8285 isolated gate driver.
[0027] In this implementation, the first set value is usually set to ensure that when the current reaches the first set value of the driver and the transistor to be tested can withstand the current value, the driver can be turned off, thereby ensuring that the device is intact. Even if the current reaches the maximum current value that the driver can accept under the setting of the first set value, when the device is damaged, the driver can be turned off to protect the devices in other modules such as the primary protection module.
[0028] Optionally, the primary protection module includes a first resistor R1 and a metal oxide semiconductor field effect transistor MOSFET, one end of the first resistor R1 is electrically connected to the first electrode of the transistor to be tested, the other end of the first resistor R1 is electrically connected to the emitter of the MOSFET, the base of the MOSFET is electrically connected to the collector of the MOSFET, and the emitter of the MOSFET is also electrically connected to the clamping protection module.
[0029] Optionally, the resistance of the first resistor R1 is 0.8-1.2Ω.
[0030] Optionally, the secondary protection module includes a plurality of resistors connected in parallel with the oscilloscope and at least one resistor connected in series with the oscilloscope.
[0031] Optionally, the secondary protection module includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are all connected to the oscilloscope, and the second resistor R2 is electrically connected between one end of the third resistor R3 and the clamping protection module.
[0032] Optionally, the resistance of the second resistor R2 is 150-250Ω, and the resistance of the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are 40-60Ω.
[0033] Optionally, the resistance of the second resistor R2 is 200Ω, and the resistance of the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 is 50Ω.
[0034] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure include at least:
[0035] In the transistor test device provided by the embodiment of the present disclosure, the on-off of the transistor to be tested is controlled by the driving protection module, and when the loop current is greater than the first set value, the transistor to be tested is controlled to be turned off, thereby protecting the transistor to be tested. In the test device, the dynamic on-resistance of the transistor to be tested is detected by an oscilloscope. During the test, when the transistor to be tested fails, the clamping protection module cuts off the circuit between the oscilloscope and the transistor to be tested, thereby preventing the oscilloscope from being damaged by excessive current impacting the oscilloscope.
[0036] At the same time, a primary protection module is provided to protect the clamp protection module from high current, thereby preventing the clamp protection module from being damaged. In addition, a secondary protection module is provided to prevent the oscilloscope from being subjected to a large voltage shock, thereby preventing the oscilloscope from being damaged by excessive voltage. In summary, the above-mentioned test device simultaneously protects the transistor to be tested, the oscilloscope, and the clamp protection module in the test device, thereby preventing damage to the transistor to be tested and the test equipment during the test process. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0038] Figure 1 is a structural schematic diagram of a transistor testing device provided by an embodiment of the present disclosure;
[0039] Figure 2 is a circuit diagram of a transistor testing device provided in an embodiment of the present disclosure.
[0040] The reference numerals are as follows:
[0041] 100: power module;
[0042] 101: drive protection module;
[0043] 102: Oscilloscope;
[0044] 103: clamp protection module;
[0045] 104: primary protection module;
[0046] 105: Secondary protection module;
[0047] 131: Isolated gate driver;
[0048] 132: a first transistor;
[0049] 141: MOSFET. DETAILED DESCRIPTION
[0050] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.
[0051] Unless otherwise defined, technical or scientific terms used herein shall have the common meanings understood by one of ordinary skill in the art to which the present disclosure belongs.
[0052] The words "first", "second", "third" and similar terms used in the patent application specification and claims of this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components.
[0053] Similarly, words such as "a" or "an" do not indicate a quantity limitation, but indicate the presence of at least one. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects.
[0054] The words "connected" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", "top", "bottom", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0055] Figure 1 is a schematic diagram of the structure of a transistor testing device provided by an embodiment of the present disclosure. Figure 1 The transistor testing device includes: a driving protection module 101, an oscilloscope 102, a clamping protection module 103, a primary protection module 104 and a secondary protection module 105.
[0056] The driving protection module 101 is electrically connected to the control electrode of the transistor to be tested, and is used to control the conduction of the transistor to be tested, and control the transistor to be tested to be turned off when the loop current is greater than a first set value.
[0057] The oscilloscope 102 is electrically connected to the first electrode and the second electrode of the transistor to be tested, and is used to detect the dynamic on-resistance of the transistor to be tested.
[0058] The clamp protection module 103 is electrically connected to the first electrode of the transistor to be tested and the oscilloscope 102 , and is used to cut off the circuit between the oscilloscope 102 and the transistor to be tested when the transistor to be tested fails.
[0059] The primary protection module 104 is electrically connected to the first electrode and the second electrode of the transistor to be tested, and is used to prevent the clamping protection module 103 from being impacted by a large current.
[0060] The secondary protection module 105 is electrically connected between the oscilloscope 102 and the clamp protection module 103 to prevent the oscilloscope 102 from being subjected to a large voltage shock.
[0061] Among them, the transistor under test is also DUT.
[0062] The dynamic on-resistance refers to the resistance between the drain and source when the device is in the fully on state.
[0063] During testing, the disclosed embodiments apply different stresses to the transistor, and then detect the resistance value between the drain and source of the transistor under each stress when the transistor is turned on to a fully on state, thereby providing data support for the research and development and optimization of the transistor under test.
[0064] In the embodiment of the present disclosure, the oscilloscope 102 may be any type of oscilloscope with a bandwidth of more than 350 MHz, so as to be able to detect the dynamic conductive resistance of the transistor to be tested.
[0065] In the transistor test device provided by the embodiment of the present disclosure, the on-off of the transistor to be tested is controlled by the driving protection module, and when the loop current is greater than the first set value, the transistor to be tested is controlled to be turned off, thereby protecting the transistor to be tested. In the test device, the dynamic on-resistance of the transistor to be tested is detected by an oscilloscope. During the test, when the transistor to be tested fails, the clamping protection module cuts off the circuit between the oscilloscope and the transistor to be tested, thereby preventing the oscilloscope from being damaged by excessive current impacting the oscilloscope.
[0066] At the same time, a primary protection module is provided to protect the clamp protection module from high current, thereby preventing the clamp protection module from being damaged. In addition, a secondary protection module is provided to prevent the oscilloscope from being subjected to a large voltage shock, thereby preventing the oscilloscope from being damaged by excessive voltage. In summary, the above-mentioned test device simultaneously protects the transistor to be tested, the oscilloscope, and the clamp protection module in the test device, thereby preventing damage to the transistor to be tested and the test equipment during the test process.
[0067] like Figure 1 As shown, the transistor testing device includes, in addition to the above modules, a power supply module 100, which is electrically connected to two ends of the transistor to be tested and is used to provide power to the transistor to be tested to form a loop.
[0068] Among them, the power module can be an IT6500 series wide-range high-power programmable DC power supply.
[0069] like Figure 1As shown, the transistor testing device further includes a resistor R11 and a resistor R12, and the resistor R11 and the resistor R12 are connected in series with the transistor to be tested.
[0070] like Figure 1 As shown, the resistor R11 and the resistor R12 are respectively arranged at two sides of the transistor to be tested.
[0071] like Figure 1 As shown, one end of the resistor R11 connected to the power source 100 is grounded.
[0072] Among them, R11 can be a 50mΩ high-precision sampling resistor, and R12 can be a 400Ω load resistor.
[0073] When the driving protection module 101 controls the transistor to be tested to be turned off, it is triggered by the loop current size, and the loop current size is the current of the loop formed by the power module 100, the transistor to be tested, the resistor R11 and the resistor R12.
[0074] In a possible implementation of the present disclosure, the driving protection module 101 is an SI8285 type isolated gate driver.
[0075] The SI8285 isolated gate driver can set the size of a first set value through a desaturation (DSAT) pin, and detect a loop current (gate-source leakage current) to determine whether the loop current exceeds the first set value.
[0076] In this implementation, the first set value is usually set to ensure that when the current reaches the first set value of the driver and the transistor to be tested can withstand the current value, the driver can be turned off, thereby ensuring that the device is intact. Even if the current reaches the maximum current value that the driver can accept under the setting of the first set value, when the device is damaged, the driver can be turned off to protect the devices in other modules such as the primary protection module.
[0077] That is, the actual size of the first setting value needs to be determined based on the structure and parameters of the transistor.
[0078] Exemplarily, the first set value may be 240 μA.
[0079] In this implementation, the driver is used to drive the switch of the transistor to be tested, and the loop current is detected. When the loop current exceeds a first set value, the transistor to be tested is controlled to be turned off to achieve protection.
[0080] In this implementation, when the loop current is greater than the first set value, the driving protection module 101 pulls down the gate-source voltage of the transistor under test to the turn-off voltage of the transistor under test (eg, Vgs=0V), thereby reducing damage to the transistor under test caused by excessive current.
[0081] In other possible implementations of the present disclosure, the driving protection module 101 is other devices as long as it can drive transistors and perform high current protection.
[0082] In the disclosed embodiment, the oscilloscope 102 may be electrically connected to other modules via a SubMiniature version A (SMA) connector or a Bayonet Nut Connector (BNC).
[0083] Figure 2 is a circuit diagram of a transistor testing device provided by an embodiment of the present disclosure. Figure 2 The clamping protection module 103 includes an isolated gate driver 131 and a first transistor 132, wherein a first electrode of the first transistor 132 is electrically connected to a first electrode of the transistor to be tested, a second electrode of the first transistor 132 is electrically connected to the secondary protection module 105, and a control electrode of the first transistor 132 is electrically connected to the isolated gate driver 131.
[0084] In the test start-up phase, the driver protection module 101 is used to control the transistor to be tested to be turned on, and then the isolated gate driver 131 is used to control the first transistor 132 to be turned on.
[0085] At the end of the test, the first transistor 132 is firstly turned off by the isolated gate driver 131 , and then the transistor to be tested is controlled to be turned off by the driving protection module 101 .
[0086] The above control method can prevent an excessively large current from passing through the clamping protection module 103 and damaging the oscilloscope 103 .
[0087] In the embodiment of the present disclosure, the isolated gate driver 131 is used to control the first transistor 132 to be turned off when the gate-source leakage current of the first transistor 132 exceeds a second set value.
[0088] Exemplarily, the second set value may be 240 μA.
[0089] In this implementation, the gate-source leakage current of the first transistor 132 is detected by the isolated gate driver 131. When the gate-source leakage current of the first transistor 132 is large, the current passing through the first transistor 132 to reach the oscilloscope 102 is also large. At this time, the first transistor 132 is controlled to be turned off to protect the oscilloscope from being impacted by large current.
[0090] In the embodiment of the present disclosure, the isolated gate driver 131 may be an SI8285 type isolated gate driver.
[0091] The SI8285 isolated gate driver can set the size of the second set value through the DSAT pin and detect whether the gate-source leakage current exceeds the second set value.
[0092] In other embodiments, the isolated gate driver 131 may also be other types of isolated gate drivers.
[0093] In the embodiment of the present disclosure, the driving protection module 101 and the isolated gate driver 131 may be powered by a DC-DC power supply, which is not shown in the figure.
[0094] See again Figure 2 The primary protection module 104 includes a first resistor R1 and a metal-oxide-semiconductor field-effect transistor (MOSFET) 141, one end of the first resistor R1 is electrically connected to the first electrode of the transistor to be tested, the other end of the first resistor R1 is electrically connected to the emitter of the MOSFET 141, the base of the MOSFET 141 is electrically connected to the collector of the MOSFET 141, and the emitter of the MOSFET 141 is also electrically connected to the clamping protection module 103.
[0095] In this implementation, a primary protection module 104 is composed of a single resistor R1 and a MOSFET, wherein the resistor R1 is burned through when the current is too large to avoid damage to the clamping protection module 103; before the resistor burns through, some energy will reach the clamping protection module 103, and the MOSFET 141 is used to consume this part of the energy by forming a loop, thereby protecting the clamping protection module 103.
[0096] In the disclosed embodiment, the resistance of the first resistor R1 is 0.8-1.2Ω.
[0097] Exemplarily, the resistance of the first resistor R1 is 1Ω.
[0098] In this implementation, by using the first resistor R1 with the above resistance value, the clamping protection module 103 can be protected by burning through the first resistor when a large current flows.
[0099] Exemplarily, the first resistor R1 may be a 0603 package resistor.
[0100] In the embodiment of the present disclosure, the MOSFET 141 may be a 1200V MOSFET capable of withstanding a voltage of up to 1200V.
[0101] In the embodiment of the present disclosure, the secondary protection module 105 includes a plurality of resistors connected in parallel with the oscilloscope 102 and at least one resistor connected in series with the oscilloscope 102 .
[0102] In this implementation, multiple resistors are connected in parallel with the oscilloscope to reduce the resistance after parallel connection, and then connected in series with at least one resistor to achieve the purpose of voltage division, thereby avoiding damage to the oscilloscope caused by a large voltage shock.
[0103] See again Figure 2 The secondary protection module 105 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are all connected to the oscilloscope 102, and the second resistor R2 is electrically connected between one end of the third resistor R3 and the clamping protection module 103.
[0104] In this implementation, four resistors are connected in parallel with the oscilloscope to reduce the resistance after parallel connection, and then connected in series with the second resistor R2 to achieve the purpose of voltage division, thereby avoiding damage to the oscilloscope caused by a large voltage shock.
[0105] In the embodiment of the present disclosure, the resistance value of the second resistor R2 is 150-250Ω, and the resistance values of the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are 40-60Ω.
[0106] Exemplarily, the resistance of the second resistor R2 is 200Ω, and the resistance of the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are 50Ω.
[0107] In this implementation, the secondary protection module 105 is composed of a 200Ω resistor and four 50Ω resistors in parallel. If the primary protection module fails, current is injected into both ends of the oscilloscope. When the oscilloscope uses an SMA / BNC connector, the impedance selection is 50Ω. The resistance of the four resistors in parallel with the oscilloscope is 10Ω, which is connected in series with the 200Ω resistor to achieve the purpose of voltage division. If the voltage is 400V and the resistor load is 400Ω, the voltage divided on the oscilloscope is only 3.7V, which is within the safety range of the oscilloscope (the oscilloscope requires a maximum voltage of 5V for 50Ω impedance), achieving the purpose of protection.
[0108] Here, the resistance load of 400Ω means that the load resistance value is calculated and determined according to the voltage and current values in the required test conditions, and a 400Ω resistor is used when the test conditions are 400V and 1A.
[0109] In the above implementation, the number of resistors connected in parallel is 4, and the number of resistors connected in series is 1. In other implementations, the number of resistors connected in parallel may be less than 4 or greater than 4, and the number of resistors connected in series may be greater than 1.
[0110] It is worth noting that the embodiments of the present disclosure do not limit how the oscilloscope measures resistance. For example, the oscilloscope measures resistance indirectly, such as by measuring the voltage across the transistor to be tested when the power module outputs a constant current, thereby determining the resistance.
[0111] In the dynamic on-resistance test process of the device provided by the embodiment of the present disclosure, the response time of the clamping protection module is very fast, and the sampling method (SMA interface sampling method) in the test device not only ensures the test accuracy of the transistor with high-frequency switching, but also ensures the safe use of the oscilloscope through the rapid response of each level of protection, timely cuts off the voltage, and prevents overcurrent and overvoltage by increasing the impedance before the interface, thereby successfully creating an accurate, safe, repeatable and reliable dynamic on-resistance test platform, and also greatly broadens the compatibility of the test platform with various instruments and equipment (various different models of power supplies and different models of oscilloscopes are compatible), so that when the transistor to be tested overcomes the current collapse problem caused by the increased dynamic on-circuit during the research and development process, it is not restricted by the test instrument, so as to reflect the characteristics of the device in the actual application process, realize accurate evaluation, and continuously improve the performance of the device.
[0112] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.
Claims
1. A transistor testing device, characterized in that: The transistor testing device comprises: A driving protection module (101) is electrically connected to a control electrode of the transistor to be tested, and is used to control the conduction of the transistor to be tested, and to control the transistor to be tested to be turned off when the loop current is greater than a first set value; An oscilloscope (102), electrically connected to the first electrode and the second electrode of the transistor to be tested, and used to detect the dynamic on-resistance of the transistor to be tested; A clamping protection module (103) is electrically connected to the first electrode of the transistor to be tested and the oscilloscope (102), and is used to cut off the circuit between the oscilloscope (102) and the transistor to be tested when the transistor to be tested fails; A primary protection module (104), electrically connected to the first electrode and the second electrode of the transistor to be tested, and used to prevent the clamping protection module (103) from being impacted by a large current; A secondary protection module (105) is electrically connected between the oscilloscope (102) and the clamping protection module (103) and is used to prevent the oscilloscope (102) from being subjected to a large voltage shock.
2. The transistor testing device according to claim 1, characterized in that: The driving protection module (101) is an SI8285 type isolated gate driver.
3. The transistor testing device according to claim 1, characterized in that: The clamping protection module (103) comprises an isolated gate driver (131) and a first transistor (132), wherein a first electrode of the first transistor (132) is electrically connected to a first electrode of the transistor to be tested, a second electrode of the first transistor (132) is electrically connected to the secondary protection module (105), and a control electrode of the first transistor (132) is electrically connected to the isolated gate driver (131).
4. The transistor testing device according to claim 3, characterized in that: The isolated gate driver (131) is used to control the first transistor (132) to be turned off when the gate-source leakage current of the first transistor (132) exceeds a second set value.
5. The transistor testing device according to claim 3, characterized in that: The isolated gate driver (131) is a SI8285 type isolated gate driver.
6. The transistor testing device according to any one of claims 1 to 5, characterized in that: The primary protection module (104) comprises a first resistor R1 and a metal oxide semiconductor field effect transistor MOSFET (141), one end of the first resistor R1 is electrically connected to the first electrode of the transistor to be tested, the other end of the first resistor R1 is electrically connected to the emitter of the MOSFET (141), the base of the MOSFET (141) is electrically connected to the collector of the MOSFET (141), and the emitter of the MOSFET (141) is also electrically connected to the clamping protection module (103).
7. The transistor testing device according to claim 6, characterized in that: The resistance of the first resistor R1 is 0.8-1.2Ω.
8. The transistor testing device according to any one of claims 1 to 5, characterized in that: The secondary protection module (105) comprises a plurality of resistors connected in parallel with the oscilloscope (102) and at least one resistor connected in series with the oscilloscope (102).
9. The transistor testing device according to claim 8, characterized in that: The secondary protection module (105) comprises a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are all connected to the oscilloscope (102), and the second resistor R2 is electrically connected between one end of the third resistor R3 and the clamping protection module (103).
10. The transistor testing device according to claim 9, characterized in that: The resistance of the second resistor R2 is 150-250Ω, and the resistance of the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are 40-60Ω.