A test circuit and apparatus for power devices

Abstract

The utility model discloses a kind of test circuit and equipment of power device, adjustable power supply unit one end in circuit is connected with first switching component through avalanche stress exerting branch, measured power device and current measurement unit;First switching component is connected with adjustable power supply unit other end through first test branch and second test branch respectively. Measured power device is connected with second switching component, and second switching component is also connected with avalanche energy test unit and on-resistance test unit respectively. Avalanche energy test unit is connected with first current setting signal, and also connected with first test branch. On-resistance test unit is connected with voltage setting signal and on-resistance test second current setting signal, and also connected with second test branch. Synchronous measurement unit is connected with measured power device and current measurement unit respectively, realizes on-resistance and avalanche energy test, both reduce economic cost and space cost, also avoid the test time cost generated due to equipment switching.

Description

Technical Field

[0001] This utility model relates to the field of power device testing, and in particular to a test circuit and device for power devices. Background Technology

[0002] Power devices (such as MOSFETs) have become core components in modern power electronic systems due to their high efficiency, high-frequency characteristics, and high reliability. The use of power devices typically focuses on two important parameters: avalanche energy and on-resistance. Based on accurate testing of these two parameters, engineers can optimize device selection, avoid design pitfalls, and thus improve system performance.

[0003] In existing power device testing solutions, avalanche energy testing equipment and on-resistance testing equipment are independent of each other. That is, avalanche energy testing equipment and on-resistance testing equipment need to be configured simultaneously to complete the avalanche energy and on-resistance tests in sequence.

[0004] This testing scheme, which involves two sets of equipment, is not only costly in terms of economy, but also requires significant time and space, which is detrimental to the development of the industry. Utility Model Content

[0005] This invention provides a test circuit for power devices. Using this test circuit to test power devices can shorten the test time and physical space required, thereby reducing economic costs.

[0006] A first aspect of this utility model provides a test circuit for a power device, the test circuit including an adjustable power supply unit, a current measurement unit, a first switching component, a second switching component, a first test branch, a second test branch, an avalanche stress application branch, a freewheeling branch, an avalanche energy test unit, a conduction resistance test unit, and a synchronous measurement unit.

[0007] The avalanche stress application branch, the power device under test, and the current measurement unit form a series branch, which is then connected in parallel with the freewheeling branch. The freewheeling branch is configured to provide a freewheeling circuit for the power device under test during avalanche energy testing. The first end of the adjustable power supply unit is connected to the first switching component via the series branch. The first switching component is also connected to the second end of the adjustable power supply unit via the first test branch and the second test branch, respectively, and is configured to switch the test branch accessed by the power device under test.

[0008] The control terminal of the power device under test is connected to the second switching component; the second switching component is also connected to the avalanche energy test unit and the on-resistance test unit respectively, and is configured to switch the test unit connected to the control terminal of the power device under test.

[0009] The avalanche energy testing unit is connected to the first test branch and connected to the first current setting signal. It is configured to drive the power device under test and the first test branch to switch on and off according to the first current setting signal and the current flowing through the first test branch.

[0010] The on-resistance test unit is connected to the second test branch and respectively connected to a voltage setting signal and a second current setting signal. It is configured to drive the power device under test and the second test branch to switch on and off according to the second current setting signal, the voltage setting signal and the current flowing through the second test branch.

[0011] The synchronous measurement unit is connected to the power device under test and the current measurement unit respectively, and is configured to measure the electrical signal of the power device under test.

[0012] Optionally, the adjustable power supply unit includes a voltage source and a voltage adjustment unit. The voltage adjustment unit includes at least two capacitor components connected in series and a first switch corresponding to each capacitor component. The series branch formed by the capacitor components is connected between the two ends of the voltage source, and each first switch is disposed between the positive terminal of its corresponding capacitor component and the avalanche stress application branch.

[0013] Optionally, the rated voltage of each capacitor component is equal.

[0014] Optionally, the rated voltages of the individual capacitor components are not all equal.

[0015] Optionally, the first test branch includes a first switching transistor and a first current sampling resistor; the first switching transistor and the first current sampling resistor are connected in series between the first switching component and the second terminal of the adjustable power supply unit.

[0016] The avalanche energy testing unit includes a comparator. The non-inverting input of the comparator is connected to the first current setting signal, the inverting input of the comparator is connected to the first current sampling resistor, and the output of the comparator is connected to the control terminal of the first switching transistor and the second switching component, respectively.

[0017] Optionally, the avalanche energy testing unit further includes a first gate driver and a buffer, wherein the first gate driver is disposed between the output of the comparator and the second switching component, and the buffer is disposed between the output of the comparator and the control terminal of the first switching transistor.

[0018] Optionally, the second test branch includes a second switching transistor and a second current sampling resistor; the second switching transistor and the second current sampling resistor are connected in series between the first switching component and the second terminal of the adjustable power supply unit.

[0019] The on-resistance testing unit includes an operational amplifier and a second gate driver. One input terminal of the operational amplifier is connected to the second current setting signal, and the other input terminal of the operational amplifier is connected to the second current sampling resistor. The input terminal of the second gate driver is connected to the voltage setting signal, and the output terminal of the second gate driver is connected to the second switching component.

[0020] Optionally, the test circuit of the power device further includes a commutation unit connected to the power device under test and configured to adjust the polarity of the power supply provided by the adjustable power supply unit to the power device under test.

[0021] Optionally, the first switching component includes a first switching switch and a second switching switch, wherein the first switching switch is disposed between the power device under test and the first test branch, and the second switching switch is disposed between the power device under test and the second test branch;

[0022] And / or, the second switching component includes a third switching switch and a fourth switching switch, the third switching switch being disposed between the avalanche energy testing unit and the control terminal of the power device under test, and the fourth switching switch being disposed between the on-resistance testing unit and the control terminal of the power device under test.

[0023] A second aspect of this utility model embodiment also provides a test device for power devices, the test device including the test circuit of any of the power devices described in the first aspect.

[0024] In the power device test circuit and equipment provided in this embodiment of the invention, the avalanche stress application branch, the power device under test, and the current measurement unit form a series branch, which is then connected in parallel with the freewheeling branch. The freewheeling branch is configured to provide a freewheeling circuit for the power device under test during avalanche energy testing. The first end of the adjustable power supply unit is connected to the first switching component via the avalanche stress application branch, the power device under test, and the current measurement unit in sequence. The first switching component is also connected to the second end of the adjustable power supply unit via the first test branch and the second test branch. The control terminal of the power device under test is connected to the second switching component, which is also connected to the avalanche energy testing unit and the on-resistance testing unit. The avalanche energy testing unit is also connected to the first current setting signal and the first test branch for avalanche energy testing. The on-resistance testing unit is connected to the voltage setting signal, the second current setting signal, and the second test branch for on-resistance testing. The synchronous measurement unit is connected to the power device under test and the current measurement unit respectively, and is configured to measure the electrical signal of the power device under test. The single circuit integration realizes the on-resistance test and avalanche energy test, avoiding the need to switch between multiple sets of test equipment, which reduces economic and space costs, and avoids the time cost caused by switching between multiple sets of equipment during the test.

[0025] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A circuit diagram of a test circuit for a power device proposed in an embodiment of this utility model;

[0028] Figure 2 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model;

[0029] Figure 3 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model;

[0030] Figure 4 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model;

[0031] Figure 5 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model;

[0032] Figure 6 A schematic diagram of the waveforms of the gate voltage, drain-source voltage, and drain-source current of the power device under test during an avalanche energy test, provided for an embodiment of this utility model.

[0033] Figure 7 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model;

[0034] Figure 8 A schematic diagram of the waveform curves of the gate voltage, drain-source voltage and drain-source current of the power device under test during the on-resistance test provided in this embodiment of the present invention;

[0035] Figure 9 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model;

[0036] Figure 10 A schematic diagram illustrating the connection relationship between a commutation unit, a current measurement unit, and a power device under test, provided for an embodiment of this utility model;

[0037] Figure 11 A schematic diagram of the waveforms of the gate voltage, forward current, and forward voltage of the body diode of a power device under test during a test of the forward voltage drop of the body diode, provided for an embodiment of this utility model.

[0038] Figure 12 This is a schematic diagram of the composition of a power device testing device provided in an embodiment of the present invention. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] To address the problems mentioned in the background art, this application proposes a test circuit for power devices to perform at least one of the following tests: on-resistance test, avalanche energy test, and body diode on-voltage drop test. For example, the power device under test may include a field-effect transistor and an insulated gate bipolar transistor (IGBT). Figure 1 This is a circuit diagram of a test circuit for a power device according to an embodiment of the present invention, with reference to... Figure 1The power device test circuit 100 includes an adjustable power supply unit 101, a current measurement unit 102, a first switching component 103, a second switching component 104, a first test branch 105, a second test branch 106, an avalanche stress application branch 107, an avalanche energy test unit 108, a conduction resistance test unit 109, and a synchronous measurement unit 110. The avalanche stress application branch 107, the power device under test (DUT), and the current measurement unit 102 form a series branch. The first end of the adjustable power supply unit 101 is connected to the first switching component 103 via the series branch formed by the avalanche stress application branch 107, the DUT, and the current measurement unit 102. The first switching component 103 is also connected to the second end of the adjustable power supply unit 101 via the first test branch 105 and the second test branch 106. The first switching component 103 is configured to switch the test branch accessed by the DUT. The control terminal of the power device under test (DUT) is connected to the second switching component 104. The second switching component 104 is also connected to the avalanche energy testing unit 108 and the on-resistance testing unit 109, respectively. The second switching component 104 is configured to switch the test units connected to the control terminal of the DUT. The avalanche energy testing unit 108 is connected to the first test branch 105 and also receives a first current setting signal. For example, the avalanche energy testing unit 108 can receive the first current setting signal through the first current setting terminal a. The avalanche energy testing unit 108 is configured to drive the DUT and the first test branch 105 to switch on and off according to the first current setting signal and the current flowing through the first test branch 105. For example, the avalanche energy testing unit 108 sends a corresponding drive signal to the control terminal of the DUT and simultaneously sends an on / off control signal to the first test branch 105 based on the comparison result between the first current setting signal and the current signal flowing through the first test branch 105. The continuity resistance testing unit 109 is connected to the second test branch 106. The continuity resistance testing unit 109 is also connected to a voltage setting signal and a second current setting signal. For example, the continuity resistance testing unit 109 can connect to the voltage setting signal via the voltage setting terminal b and to the second current setting signal via the second current setting terminal c. The continuity resistance testing unit 109 is configured to drive the power device under test (DUT) and the second test branch 106 to switch on and off based on the second current setting signal, the voltage setting signal, and the current flowing through the second test branch 106. For example, the continuity resistance testing unit 109 sends a corresponding drive signal to the control terminal of the power device under test (DUT) based on the second current setting signal, the voltage setting signal, and the current signal flowing through the second test branch 106, and simultaneously sends a switching control signal to the second test branch 106. The synchronous measurement unit 110 is connected to both the power device under test (DUT) and the current measurement unit 102, and is configured to measure the electrical signals of the power device under test (DUT).

[0042] Specifically, the device under test (DUT) is the device under test (DUT) to which the test circuit involved in this embodiment of the present invention is applicable. The adjustable power supply unit 101 is an adjustable voltage source supply component of the test circuit. Its output bus voltage can be adjusted according to the test stage. For example, the adjustable power supply unit 101 may include a voltage source and a corresponding voltage adjustment circuit. The voltage adjustment circuit may be provided with multiple sets of capacitor components. Depending on the voltage required in the test stage, the voltage adjustment circuit may use at least one set of corresponding capacitor components to connect to the test circuit, thereby providing the bus voltage of the corresponding voltage level to the device under test (DUT).

[0043] The avalanche stress application branch 107 refers to a component that uses its inductive device to store energy in order to apply energy to the power device under test (DUT) during the avalanche energy testing phase. Exemplarily, the avalanche stress application branch 107 also includes a parallel branch consisting of an inductor and a switch. Furthermore, to provide freewheeling current to the DUT during the avalanche energy testing phase, the power device test circuit 100 also includes a freewheeling branch 111. The freewheeling branch 111 is connected in parallel with the series branch formed by the avalanche stress application branch 107, the DUT, and the current measurement unit 102, and is configured to provide a freewheeling loop for the DUT during the avalanche energy test. Exemplarily, the freewheeling branch 111 may include a freewheeling diode D, with its anode connected to the connection point between the current measurement unit 102 and the first switching component 103, and its cathode connected to the connection point between the avalanche stress application branch 107 and the adjustable power supply unit 101.

[0044] The current measurement unit 102 refers to a current sampling component installed on the power supply line of the power device under test (DUT). It can sample the current flowing through the DUT. For example, the current measurement unit 102 may include a sampling resistor. The sampling resistor is installed between the source of the DUT and the first switching component 103. Its end closer to the DUT can be used as a current sampling output terminal and connected to the synchronous measurement unit 110 to realize the output of the current sampling result to the synchronous measurement unit 110.

[0045] The first terminal of the first switching component 103 is connected to the power device under test (DUT) via the current measurement unit 102. The first terminal of the second terminal of the first switching component 103 is connected to the second terminal of the adjustable power supply unit 101 via the first test branch 105. The second terminal of the second terminal of the first switching component 103 is connected to the second terminal of the adjustable power supply unit 101 via the second test branch 106. The first switching component 103 can switch the connection relationship between the power device under test and the first test branch 105 and the second test branch 106. For example, the first switching component 103 includes a first switching switch k1 and a second switching switch k2. The first switching switch k1 is disposed between the power device under test (DUT) and the first test branch 105, and the second switching switch k2 is disposed between the power device under test (DUT) and the second test branch 106. During the avalanche energy test phase, the first switching switch k1 of the first switching component 103 is turned on while the second switching switch k2 is turned off, so as to connect the first test branch 105 with the power device under test (DUT); during the on-resistance test phase or the body diode on-state voltage drop test phase, the second switching switch k2 of the first switching component 103 is turned on while the first switching switch k1 is turned off, so as to connect the second test branch 106 with the power device under test (DUT).

[0046] The first end of the second switching component 104 is connected to the control terminal of the power device under test (DUT), the first end of the second end of the second switching component 104 is connected to the avalanche energy testing unit 108, and the second end of the second end of the second switching component 104 is connected to the on-resistance testing unit 109. The second switching component 104 can switch the connection relationship between the control terminal of the DUT and the on-resistance testing unit 109 and the avalanche energy testing unit 108. For example, the second switching component 104 includes a third switching switch k3 and a fourth switching switch k4. The third switching switch k3 is disposed between the avalanche energy testing unit 108 and the control terminal of the DUT, and the fourth switching switch k4 is disposed between the on-resistance testing unit 109 and the control terminal of the DUT. During the avalanche energy test phase, the third switching switch k3 of the second switching component 104 is turned on while the fourth switching switch k4 is turned off, so that the avalanche energy test unit 108 is connected to the control terminal of the power device under test (DUT). During the on-resistance test phase or the body diode on-voltage drop test phase, the fourth switching switch k4 of the second switching component 104 is turned on while the third switching switch k3 is turned off, so that the on-resistance test unit 109 is connected to the control terminal of the power device under test (DUT).

[0047] The first test branch 105 is a branch related to avalanche energy testing, which can adjust the on / off state of the test circuit during the avalanche energy testing phase. For example, the first test branch 105 may include a series-connected switching transistor and a sampling resistor. Correspondingly, the avalanche energy testing unit 108 is the control component for avalanche energy testing. It receives a first current setting signal for avalanche energy testing and can determine the required avalanche energy test current based on the first current setting signal. For example, the first current setting signal can be provided by an external controller. The avalanche energy testing unit 108 is also connected to the first test branch 105 and can sample the current flowing through the first test branch 105 (which also flows through the power device under test, DUT) during the avalanche energy testing phase. The avalanche energy testing unit 108 can control the on / off state of the power device under test (DUT) and the first test branch 105 based on the comparison result between the sampled current of the first test branch 105 and the first current setting signal. For example, the avalanche energy testing unit 108 may include a comparator to compare the sampled current of the first test branch 105 with the first current setting signal. During the avalanche energy testing phase, if the current flowing through the first test branch 105 is detected to be less than the first current setting signal, the avalanche energy testing unit 108 controls both the power device under test (DUT) and the first test branch 105 to remain on; once the current flowing through the first test branch 105 is detected to be equal to the first current setting signal, the avalanche energy testing unit 108 controls both the power device under test (DUT) and the first test branch 105 to be turned off, thereby causing the power device under test (DUT) to enter an avalanche state, thus realizing the avalanche energy test of the power device under test (DUT).

[0048] The second test branch 106 is related to the on-resistance test and the body diode on-voltage drop test. It can adjust the test current flowing through the power device under test (DUT) during the on-resistance test and the body diode on-voltage drop test. For example, the second test branch 106 may include a series-connected switching transistor and a sampling resistor. Correspondingly, the on-resistance test unit 109 is the control component for the on-resistance test and the body diode on-voltage drop test. It receives the voltage setting signal and the second current setting signal corresponding to the on-resistance test or the body diode on-voltage drop test. It can determine the test voltage to be applied to the DUT during the on-resistance test and the body diode on-voltage drop test based on the voltage setting signal, and it can also determine the constant current required during the on-resistance test and the body diode on-voltage drop test based on the second current setting signal. For example, the voltage setting signal and the second current setting signal can be provided by the controller of an external device. The on-resistance test unit 109 is also connected to the second test branch 106. During the on-resistance test and the body diode forward voltage drop test, the second test branch 106 samples the current flowing through the power device under test (DUT). The on-resistance test unit 109 can adjust the test voltage applied to the control terminal of the power device under test (DUT) according to the voltage setting signal, and can also adjust the test current according to the sampled current flowing through the second test branch 106 and the second current setting signal.

[0049] For example, the on-resistance testing unit 109 may include an operational amplifier to control the conduction level of the second test branch 106 by combining the current flowing through the second test branch 106 with the test setting current. During the on-resistance test or body diode forward voltage drop test, on the one hand, the on-resistance testing unit 109 also adjusts the voltage applied to the control terminal of the power device under test (DUT) according to the voltage setting signal to set the test voltage conditions; on the other hand, the on-resistance testing unit 109 can control the second test branch 106 to be fully on during charging. Once the current flowing through the second test branch 106 rises to equal the constant current, the on-resistance testing unit 109 can adjust the conduction level of the second test branch 106 according to the relative relationship between the current in the second test branch 106 and the set constant current, thus achieving closed-loop feedback regulation of the current flowing through the second test branch 106.

[0050] The synchronous measurement unit 110 is a component that measures the electrical signals of the power device under test (DUT). It is connected to the three terminals of the DUT and can detect the voltages at the three terminals, such as the gate-source voltage and drain-source voltage. It is also connected to the current measurement unit 102 to detect the test current flowing through the DUT. For example, the measurement branch may include a volt-ampere meter with at least two ranges to accommodate the measurement of electrical signals under different conditions of avalanche energy testing and on-resistance testing. During the avalanche energy testing phase, the measurement branch can detect the gate-source voltage, drain-source voltage, and drain-source current of the DUT, enabling state testing of the DUT under avalanche conditions. During the on-resistance testing and body diode forward voltage drop testing phases, the measurement branch can detect the drain-source voltage of the DUT, enabling testing of the body diode forward voltage drop. It can also combine the drain-source voltage of the DUT with the constant current flowing through it to test the on-resistance.

[0051] In the power device test circuit provided in this embodiment, the first end of the adjustable power supply unit is connected to the first switching component via the avalanche stress application branch, the power device under test, and the current measurement unit. The first switching component is also connected to the second end of the adjustable power supply unit via the first test branch and the second test branch. The control terminal of the power device under test is connected to the second switching component, which is also connected to the avalanche energy test unit and the on-resistance test unit. The avalanche energy test unit is also connected to the first current setting signal and the first test branch for avalanche energy testing. The on-resistance test unit is connected to the voltage setting signal, the second current setting signal, and the second test branch for on-resistance testing. The synchronous measurement unit is connected to the power device under test and the current measurement unit and is configured to measure the electrical signal of the power device under test. A single circuit integrates on-resistance testing and avalanche energy testing, avoiding the need to switch between multiple sets of test equipment, thus reducing economic and space costs and avoiding the testing time costs caused by equipment switching.

[0052] Optionally, Figure 2 A circuit diagram of another power device test circuit provided in this embodiment of the present invention, based on the foregoing embodiments, with reference to... Figure 2 The adjustable power supply unit 101 includes a voltage source DC and a voltage adjustment unit 201. The voltage adjustment unit 201 includes at least two capacitor components 202 connected in series and a first switch 203 corresponding to each capacitor component 202. The series branch formed by the capacitor components 202 is connected between the two ends of the voltage source DC. Each first switch 203 is disposed between the positive terminal of its corresponding capacitor component 202 and the avalanche stress application branch 107.

[0053] Specifically, the DC voltage source can charge the capacitor assembly 202 in the voltage adjustment unit 201. The capacitor assembly 202 can be a parallel assembly of multiple capacitors, and the voltage adjustment unit 201 can adjust the number of capacitor assemblies 202 connected in series by switching the on / off states of each first switch 203, thereby adjusting the voltage level output to the test bus. For example, Figure 3 A circuit diagram of a test circuit for another power device provided in this embodiment of the present invention, in conjunction with... Figure 2 and Figure 3 The voltage adjustment unit 201 may include five capacitor assemblies 202 (i.e. Figure 3 The rated voltages of each capacitor assembly 202 (C1, C2, C3, C4, and C5) can be equal. For example, the rated voltages of all five capacitor assemblies 202 can be equal to 200V. Thus, the voltage adjustment unit 201 can utilize five first switches 203 (i.e., ... Figure 3 The switching combinations of S1, S2, S3, S4 and S5 in the circuit switch the bus voltage to five levels: 200V, 400V, 600V, 800V and 1000V. Figure 4 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model is shown below. Figure 4 The voltage adjustment unit 201 may include five capacitor assemblies 202 (i.e. Figure 4 The rated voltages of the five capacitor components 202 (C1, C2, C3, C4, and C5) may not be equal. For example, in the direction from the negative terminal of the DC voltage source to the positive terminal, the rated voltages of the five capacitor components 202 are 20V, 50V, 100V, 150V, and 200V respectively. Thus, the voltage adjustment unit 201 can utilize the five first switches 203 (i.e., ... Figure 4 The switching combinations of S1, S2, S3, S4 and S5 in the circuit switch the bus voltage to five levels: 20V, 70V, 170V, 320V and 520V.

[0054] For example, Figure 5 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model is shown below. Figure 5Taking the voltage adjustment unit 201, which includes two capacitor components 202, as an example, during the avalanche energy testing phase, the power device under test (DUT) requires a higher bus voltage. In this case, the first switch 203 corresponding to the first capacitor component C1 is turned on, and the first switch S2 corresponding to the second capacitor component C2 is turned off, so that the series component composed of the first capacitor component C1 and the second capacitor component C2 supplies power to the power device under test (DUT) and provides a higher bus voltage. The bus voltage output after the first capacitor component 202 and the second capacitor component 202 are connected in series is equal to the sum of the rated voltage of the first capacitor component 202 and the rated voltage of the second capacitor component 202. During the on-resistance test or the body diode on-voltage drop test, the power device under test (DUT) requires a lower bus voltage. In this case, the first switch S1 corresponding to the first capacitor assembly C1 is open while the first switch S2 corresponding to the second capacitor assembly C2 is open, so that the second capacitor assembly 202 supplies power to the power device under test (DUT) and provides a lower bus voltage to the power device under test (DUT). The bus voltage output by the second capacitor assembly 202 is equal to the rated voltage of the second capacitor assembly 202.

[0055] The adjustable power supply unit in the power device test circuit provided in this embodiment includes a voltage source and a voltage adjustment unit. The voltage adjustment unit includes at least two capacitor components connected in series and a first switch corresponding to each capacitor component. The series branch formed by the capacitor components is connected between the two ends of the voltage source. Each first switch is set between the positive terminal of its corresponding capacitor component and the avalanche stress application branch, thereby realizing the adjustment of the bus voltage. This allows the test circuit to flexibly adapt to various test scenarios and broadens the application range of the test circuit.

[0056] Optionally, based on the foregoing embodiments, refer to... Figure 5 The first test branch 105 includes a first switching transistor M1 and a first current sampling resistor R1 connected in series; the first switching transistor M1 and the first current sampling resistor R1 are connected in series between the first switching component 103 and the second terminal of the adjustable power supply unit 101. The avalanche energy test unit 108 includes a comparator 501, the non-inverting input terminal of the comparator 501 is connected to a first current setting signal, and the inverting input terminal of the comparator 501 is connected to the first current sampling resistor R1. The avalanche energy test unit 108 also includes a first gate driver 502 and a buffer 503, the first gate driver 502 is disposed between the output terminal of the comparator 501 and the second switching component 104, and the buffer 503 is disposed between the output terminal of the comparator 501 and the control terminal of the first switching transistor M1.

[0057] Specifically, the first switching transistor M1 is the conduction state control device of the first test branch 105. For example, the first switching transistor M1 can be an N-type field-effect transistor. The first current sampling resistor R1 is a current sampling device disposed on the first test branch 105. The end of R1 connected to the first switching transistor M1 can serve as a current feedback terminal to feed back the first current sampling signal of the first test branch 105 to the avalanche energy testing unit 108.

[0058] The non-inverting input of comparator 501 is connected to a first current setting signal, and the inverting input is connected to a first current sampling resistor R1 on the first test branch 105. The first current setting signal can be a voltage signal provided by a controller or other DC voltage source, and its voltage level is positively correlated with the set value of the avalanche energy test current. The first current sampling signal fed back to comparator 501 by the first current sampling resistor R1 is the voltage signal at its terminal connected to the first switching transistor M1, and its voltage level is positively correlated with the current flowing through the first switching transistor M1. Comparator 501 can output a corresponding electrical signal based on the comparison result of the voltage levels of the first current setting signal and the first current sampling signal. For example, comparator 501 can output a high level when the voltage of the first current sampling signal is less than the voltage of the first current setting signal, and output a low level when the voltage of the first current sampling signal is greater than or equal to the voltage of the first current setting signal.

[0059] The first gate driver 502 can send a gate drive signal to the gate of the power device under test (DUT) according to the output signal of the comparator 501 to drive the DUT to turn on and off. For example, when the comparator 501 outputs a high level, the first gate driver 502 converts the received high level into a voltage signal to control the DUT to turn on, and controls the DUT to turn on via the second switching component 104. When the comparator 501 outputs a low level, the first gate driver 502 converts the received low level into a voltage signal to control the DUT to turn off, and controls the DUT to turn off via the second switching component 104. The comparator 501 is a comparator with a latching function, which can prevent the comparator 501 from flipping and the first switch M1 from turning on due to the decrease in the current sampling signal after the first switch M1 is turned off.

[0060] Buffer 503 can generate a corresponding buffer drive signal based on the output signal of comparator 501 to drive the rapid switching of the first switch M1. For example, when comparator 501 outputs a high level, buffer 503 can convert the received high level into a voltage signal that controls the first switch M1 to turn on. When comparator 501 outputs a low level, buffer 503 can convert the received low level into a voltage signal that controls the first switch M1 to turn off. Buffer 503 can achieve the functions of driving, isolating, and protecting the first switch M1, and can also improve the state switching speed of the first switch M1, thereby improving the reliability of the test circuit.

[0061] For example, Figure 6 This invention provides a schematic diagram of the waveforms of the gate voltage, drain-source voltage, and drain-source current of the power device under test during an avalanche energy test, in conjunction with an embodiment of the present invention. Figure 5 and Figure 6Taking the voltage adjustment unit 201, which includes two capacitor components 202, as an example, when performing avalanche energy testing on the power device under test (DUT), the first switch S1 corresponding to the first capacitor component C1 in the voltage adjustment unit 201 is turned on while the first switch S2 corresponding to the second capacitor component C2 is turned off, so as to provide the DUT with a higher bus voltage level required for avalanche energy testing. Simultaneously, the first switching switch k1 in the first switching component 103 is turned on while the second switching switch k2 is turned off; and the third switching switch k3 in the second switching component 104 is turned on while the fourth switching switch k4 is turned off. During the avalanche energy testing process, between times t0 and t1, the comparator 501 compares the first current setting signal with the current sampling signal fed back by the first current sampling resistor R1 to determine whether the current flowing through the first test branch 105 has increased to be equal to the avalanche energy testing current. If the current in the first test branch 105 is less than the avalanche energy testing current, the comparator 501 outputs a high level. On one hand, the first gate driver 502 generates a gate control signal based on the high level output of the comparator 501 and supplies it to the gate of the power device under test (DUT) to keep the DUT on. On the other hand, the buffer 503 generates a control signal based on the high level output of the comparator 501 and supplies it to the gate of the first switch M1 to keep the first switch M1 on. Once the current of the first test branch 105 is greater than or equal to the avalanche energy test current, i.e., at time t1 shown in the figure, the comparator 501 outputs a low level. Between times t1 and t2, on the one hand, the first gate driver 502 generates a gate control signal based on the low level output of the comparator 501 and supplies it to the gate of the DUT to keep the DUT off. On the other hand, the buffer 503 generates a control signal based on the low level output of the comparator 501 to keep the first switch M1 off simultaneously. When the power device under test (DUT) and the first switch M1 are simultaneously triggered to turn off, the first switch S1 corresponding to the first capacitor component C1 in the voltage adjustment unit 201 is also synchronously turned off, thereby cutting off the high-voltage DC power supply to the DUT during the avalanche test. Under these circumstances, the inductor in the avalanche stress application branch 107 will provide avalanche stress to the DUT, after which the DUT enters an avalanche state, and the drain-source voltage VDS of the DUT will rise to the avalanche breakdown voltage. During the avalanche energy test, the synchronous measurement unit 110 collects the drain-source voltage VDS and drain-source current IDS of the DUT.Based on the avalanche breakdown voltage BVds detected between times t1 and t2 and the avalanche energy test current IAS at time t1, the energy of a single avalanche can be calculated using the avalanche energy calculation formula EAS = 1 / 2 * IAS * BVds * dt, where EAS is the energy of a single avalanche; IAS is the avalanche energy test current; BVds is the avalanche breakdown voltage; and dt is the duration of the avalanche state, dt = t2 - t1.

[0062] The first test branch in the power device test circuit provided in this embodiment includes a first switching transistor and a first current sampling resistor; the first switching transistor and the first current sampling resistor are connected in series between the first switching component and the second terminal of the adjustable power supply unit. The avalanche energy test unit includes a comparator, a first gate driver, and a buffer. The non-inverting input terminal of the comparator is connected to a first current setting signal, and the inverting input terminal of the comparator is connected to the first current sampling resistor. The first gate driver is located between the output terminal of the comparator and the second switching component, and the buffer is located between the output terminal of the comparator and the control terminal of the first switching transistor. The avalanche energy test unit uses the comparator, the first gate driver, and the buffer to realize the control related to the avalanche energy test of the circuit, and the circuit structure is simple, reducing the test cost.

[0063] Optionally, Figure 7 A circuit diagram of another power device test circuit provided in this embodiment of the present invention, based on the foregoing embodiments, with reference to... Figure 7 The second test branch 106 includes a second switching transistor M2 and a second current sampling resistor R2. The second switching transistor M2 and the second current sampling resistor R2 are connected in series between the first switching component 103 and the second terminal of the adjustable power supply unit 101. The on-resistance test unit 109 includes an operational amplifier 701 and a second gate driver 702. One input terminal of the operational amplifier 701 is connected to a second current setting signal, and the other input terminal of the operational amplifier 701 is connected to the second current sampling resistor R2. The input terminal of the second gate driver 702 is connected to a voltage setting signal, and the output terminal of the second gate driver 702 is connected to the second switching component 104.

[0064] Specifically, the second switch M2 is the conduction state control device of the second test branch 106. For example, the second switch M2 can be an N-type field-effect transistor. The second current sampling resistor R2 is a current sampling device disposed on the second test branch 106. The end of R2 connected to the second switch M2 can serve as a current feedback terminal, feeding back the second current sampling signal of the second test branch 106 to the conduction resistance test unit 109.

[0065] One input terminal of operational amplifier 701 is connected to a second current setting signal, and the other input terminal is connected to a second current sampling resistor R2 to receive a second current sampling signal. The second current setting signal can be a voltage signal provided by a controller or other DC voltage source, and its voltage level can be positively correlated with the set value of the test current required for the on-resistance test. The second current sampling signal fed back to operational amplifier 701 by the second current sampling resistor R2 is the voltage signal at its terminal connected to the second switching transistor M2, and its voltage level is positively correlated with the current flowing through the second switching transistor M2. Operational amplifier 701 can generate a corresponding conduction control signal based on the second current setting signal and the second current sampling signal to control the maximum current of the second switching transistor M2 to be equal to the test current required for the on-resistance test, thereby generating a constant current plateau stage for on-resistance testing and body diode forward voltage drop testing.

[0066] The second gate driver 702 can generate a corresponding gate drive signal based on the received voltage setting signal to drive the power device under test (DUT) to switch on and off. For example, when the voltage setting signal is an on voltage, the second gate driver 702 can convert the received voltage into a corresponding gate control signal, which is then supplied to the gate of the DUT via the second switching component 104. When the voltage setting signal is an off voltage, the second gate driver 702 can convert the received voltage into a corresponding gate control signal, which is then supplied to the gate of the DUT via the second switching component 104.

[0067] For example, Figure 8 This invention provides a schematic diagram of the waveforms of the gate voltage, drain-source voltage, and drain-source current of the power device under test during on-resistance testing, in conjunction with an embodiment of the present invention. Figure 7 and Figure 8Taking the voltage adjustment unit 201, which includes two capacitor components 202, as an example, when performing a continuity test on the power device under test (DUT), the first switch S1 corresponding to the first capacitor component C1 in the voltage adjustment unit 201 is turned off, while the first switch S2 corresponding to the second capacitor component C2 is turned on. The switch in the avalanche energy stress application branch 107 is turned on to provide the DUT with a lower voltage level bus voltage required for the continuity test. Simultaneously, the second switching switch k2 in the first switching component 103 is turned on, while the first switching switch k1 is turned off. Furthermore, the fourth switching switch k4 in the second switching component 104 is turned on, while the third switching switch k3 is turned off. During the continuity test, the second gate driver 702 applies a gate control signal VGS of the corresponding voltage level to the gate of the DUT according to the voltage setting signal, thereby controlling the gate voltage of the DUT during the continuity test. Operational amplifier 701 applies a conduction control signal of corresponding voltage level to the gate of the second switch M2 based on the input second current sampling signal and second current setting signal to control the conduction level of the second switch M2. The second current setting signal characterizes the constant current required for the on-resistance test. The power device under test (DUT) is turned on at time t0. During the initial test phase, the sampling current of the second switch M2 is less than the required constant current, and operational amplifier 701 outputs a higher voltage conduction control signal to fully turn on the second switch M2. Once the sampling current of the second switch M2 rises to be greater than or equal to the required constant current, operational amplifier 701 lowers the voltage value of the conduction control signal to limit the conduction level of the second switch M2, thereby limiting the maximum current that can flow through the second switch M2. Specifically, operational amplifier 701 adjusts the conduction signal of the second switch M2 in real time based on the input second current sampling signal and second current setting signal, achieving closed-loop feedback regulation of the current flowing through the second switch M2 to generate a constant current plateau period. During the constant current plateau period, a constant current flows from the drain to the source of the power device under test (DUT). The synchronous measurement unit 110 acquires the drain-source voltage VDS and drain-source current IDS of the DUT. The drain-source voltage and drain-source current corresponding to the constant current plateau period are substituted into the on-resistance calculation formula RDSON = VDS / IDS = VDS1 / IDS1, where VDS1 is the drain-source voltage corresponding to the constant current plateau period, and IDS1 is the drain-source current (i.e., the constant current) corresponding to the constant current plateau period. Furthermore, the average value of multiple sets of data can be calculated to improve the accuracy of the on-resistance test. After the test is completed, the DUT returns to off at time t1.

[0068] The power device test circuit provided in this embodiment includes a second test branch comprising a second switching transistor and a second current sampling resistor. The second switching transistor and the second current sampling resistor are connected in series between the first switching component and the second terminal of the adjustable power supply unit. The on-resistance test unit includes an operational amplifier and a second gate driver. One input terminal of the operational amplifier is connected to a second current setting signal, and the other input terminal of the operational amplifier is connected to the second current sampling resistor. The input terminal of the second gate driver is connected to a voltage setting signal, and the output terminal of the second gate driver is connected to the second switching component. The on-resistance test unit utilizes the operational amplifier and the second gate driver to implement the relevant control for on-resistance testing. By using the operational amplifier to perform closed-loop feedback control of the current in the test circuit, the setting accuracy of the constant current is improved, further enhancing the reliability of the test results.

[0069] Optionally, Figure 9 A circuit diagram of a test circuit for another power device provided in an embodiment of this utility model. Figure 10 This utility model provides a schematic diagram of the connection relationship between a commutation unit, a current measurement unit, and a power device under test, based on the aforementioned embodiments and in conjunction with... Figure 9 and Figure 10 The power device test circuit 100 also includes a commutation unit 901, which is connected to the power device under test (DUT) and configured to adjust the polarity of the power supply provided by the adjustable power supply unit 101 to the power device under test (DUT).

[0070] Specifically, the commutation unit 901 may include four commutation switches. A first commutation switch T1, the power device under test (DUT), the current measurement unit 102, and a second commutation switch T2 are connected in series between the avalanche stress application branch 107 and the first terminal of the first switching component 103. A third commutation switch T3 is located between the first terminal of the first commutation switch T1 and the first terminal of the second commutation switch T2. A fourth commutation switch T4 is located between the second terminal of the first commutation switch T1 and the second terminal of the second commutation switch T2. By controlling the on / off combination of the four commutation switches, the relative polarity of the adjustable power supply unit 101 and the power device under test (DUT) can be switched, enabling the testing of the body diode forward voltage drop of the power device under test (DUT). For example, all four commutation switches may be IGBTs.

[0071] For example, when both the first commutation switch T1 and the second commutation switch T2 are turned on and both the third commutation switch T3 and the fourth commutation switch T4 are turned off, the test current flows from the drain to the source of the power device under test (DUT), allowing for on-resistance testing of the DUT. The on-resistance testing process has been described in detail in previous embodiments and will not be repeated here.

[0072] With the first commutation switch T1 and the second commutation switch T2 both off and the third commutation switch T3 and the fourth commutation switch T4 both on, the test current flows from the source to the drain of the power device under test (DUT), which allows for a body diode forward voltage drop test on the DUT.

[0073] Figure 11 This utility model provides a schematic diagram of the waveforms of the gate voltage, forward current, and forward voltage of the body diode of a power device under test during the on-state voltage drop test of the body diode. Figure 9 , Figure 10 and Figure 11Taking the voltage adjustment unit 201, which includes two capacitor components 202, as an example, when performing a body diode forward voltage drop test on the power device under test (DUT), the first switch S1 corresponding to the first capacitor component C1 in the voltage adjustment unit 201 is turned off, while the first switch S2 corresponding to the second capacitor component C2 is turned on. The switch in the avalanche energy stress application branch 107 is turned on to provide the DUT with a lower voltage level bus voltage required for the body diode forward voltage drop test. At the same time, the second switching switch k2 in the first switching component 103 is turned on, while the first switching switch k1 is turned off. The fourth switching switch k4 in the second switching component 104 is also turned on, while the third switching switch k3 is turned off. In addition, the polarity of the power supply provided by the adjustable power supply unit 101 to the DUT is reversed using the commutation unit 901, connecting the positive terminal of the adjustable power supply to the source terminal of the DUT, and coupling the negative terminal of the adjustable power supply to the drain terminal of the DUT. During the body diode forward voltage drop test, the second gate driver 702 applies a gate control signal VGS of the corresponding voltage level to the gate of the power device under test (DUT) according to the voltage setting signal, thereby controlling the gate voltage of the DUT during the body diode forward voltage drop test. The operational amplifier 701, based on the input second current sampling signal and second current setting signal, applies a turn-on control signal of the corresponding voltage level to the gate of the second switch M2 to control the conduction level of the second switch M2. The second current setting signal characterizes the constant current required for the body diode forward voltage drop test. The DUT is turned off at time t0, and then enters the initial test phase. Since the sampling current of the second switch M2 is greater than the constant current required for the test, the operational amplifier 701 outputs a higher voltage turn-on control signal, controlling the second switch M2 to fully conduct. Once the sampling current of the second switch M2 drops to less than or equal to the constant current required for the test, the operational amplifier 701 lowers the voltage value of the conduction control signal to limit the conduction degree of the second switch M2, thereby limiting the maximum reverse current (regardless of direction) that can flow through the second switch M2. Specifically, the operational amplifier 701 adjusts the conduction signal of the second switch M2 in real time according to the input second current sampling signal and the second current setting signal, realizing closed-loop feedback regulation of the current flowing through the second switch M2 to generate a reverse constant current plateau period. During the constant current plateau period, the constant current flows from the anode to the cathode of the body diode in the power device under test (DUT). The synchronous measurement unit 110 collects the forward current IF and forward voltage VF of the body diode in the DUT to test the forward conduction voltage drop of the body diode. After the test is completed, the power device under test (DUT) can resume conduction at time t1.

[0074] The power device test circuit provided in this embodiment also includes a commutation unit, which is connected to the power device under test (DUT) and configured to adjust the polarity of the power supplied by the adjustable power supply unit to the DUT. This enables the testing of the body diode forward voltage drop of the DUT. A single circuit integrates avalanche energy testing, on-resistance testing, and body diode forward voltage drop testing of the power device, saving the device setup and initialization time for multiple tests and shortening the overall testing time. Simultaneously, it saves physical space occupied by the equipment, shortens the travel distance of the DUT within the test station, and reduces the interval between multiple tests. Combining these two points, the circuit improves testing efficiency.

[0075] This utility model embodiment also provides a testing device for power devices. Figure 12 This is a schematic diagram of the composition of a power device testing device provided in an embodiment of the present invention, with reference to... Figure 12 The power device test equipment 1200 includes the power device test circuit 100 of any of the foregoing embodiments. Exemplarily, the power device test equipment 1200 may further include a controller 1201, which may be connected to the power device test circuit 100 to control the test process, monitor the status, and acquire results of the power device test circuit 100. The controller 1201 may be at least one of a microcontroller and a monitoring computer.

[0076] In the power device test circuit and equipment provided in this embodiment, the first end of the adjustable power supply unit is connected to the first switching component via the avalanche stress application branch, the power device under test, and the current measurement unit. The first switching component is also connected to the second end of the adjustable power supply unit via the first test branch and the second test branch. The control terminal of the power device under test is connected to the second switching component, which is also connected to the avalanche energy test unit and the on-resistance test unit. The avalanche energy test unit is also connected to the first current setting signal and the first test branch for avalanche energy testing. The on-resistance test unit is connected to the voltage setting signal, the second current setting signal, and the second test branch for on-resistance testing. The synchronous measurement unit is connected to the power device under test and the current measurement unit and is configured to measure the electrical signal of the power device under test. A single circuit integrates on-resistance testing and avalanche energy testing, avoiding the need to switch between multiple sets of test equipment, thus reducing economic and space costs and avoiding the testing time costs caused by equipment switching.

[0077] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0078] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A test circuit for a power device, characterized in that, include: Adjustable power supply unit, current measurement unit, first switching component, second switching component, first test branch, second test branch, avalanche stress application branch, freewheeling branch, avalanche energy test unit, on-resistance test unit and synchronous measurement unit; The avalanche stress application branch, the power device under test, and the current measurement unit form a series branch, which is then connected in parallel with the freewheeling branch. The freewheeling branch is configured to provide a freewheeling circuit for the power device under test during avalanche energy testing. The first end of the adjustable power supply unit is connected to the first switching component via the series branch. The first switching component is also connected to the second end of the adjustable power supply unit via the first test branch and the second test branch, respectively, and is configured to switch the test branch accessed by the power device under test. The control terminal of the power device under test is connected to the second switching component; the second switching component is also connected to the avalanche energy test unit and the on-resistance test unit respectively, and is configured to switch the test unit connected to the control terminal of the power device under test. The avalanche energy testing unit is connected to the first test branch and connected to the first current setting signal. It is configured to drive the power device under test and the first test branch to switch on and off according to the first current setting signal and the current flowing through the first test branch. The on-resistance test unit is connected to the second test branch and respectively connected to a voltage setting signal and a second current setting signal. It is configured to drive the power device under test and the second test branch to switch on and off according to the second current setting signal, the voltage setting signal and the current flowing through the second test branch. The synchronous measurement unit is connected to the power device under test and the current measurement unit respectively, and is configured to measure the electrical signal of the power device under test.

2. The test circuit for the power device according to claim 1, characterized in that, The adjustable power supply unit includes a voltage source and a voltage adjustment unit. The voltage adjustment unit includes at least two capacitor components connected in series and a first switch corresponding to each capacitor component. The series branch formed by the capacitor components is connected between the two ends of the voltage source. Each adjustment switch is located between the positive terminal of its corresponding capacitor component and the avalanche stress application branch.

3. The test circuit for the power device according to claim 2, characterized in that, The rated voltages of all capacitor components are equal.

4. The test circuit for the power device according to claim 2, characterized in that, The rated voltages of the individual capacitor components are not all equal.

5. The test circuit for the power device according to claim 1, characterized in that, The first test branch includes a first switching transistor and a first current sampling resistor; the first switching transistor and the first current sampling resistor are connected in series between the first switching component and the second terminal of the adjustable power supply unit; The avalanche energy testing unit includes a comparator. The non-inverting input of the comparator is connected to the first current setting signal, the inverting input of the comparator is connected to the first current sampling resistor, and the output of the comparator is connected to the control terminal of the first switching transistor and the second switching component, respectively.

6. The test circuit for the power device according to claim 5, characterized in that, The avalanche energy testing unit further includes a first gate driver and a buffer. The first gate driver is disposed between the output of the comparator and the second switching component, and the buffer is disposed between the output of the comparator and the control terminal of the first switching transistor.

7. The test circuit for the power device according to claim 1, characterized in that, The second test branch includes a second switching transistor and a second current sampling resistor; the second switching transistor and the second current sampling resistor are connected in series between the first switching component and the second terminal of the adjustable power supply unit. The on-resistance testing unit includes an operational amplifier and a second gate driver. One input terminal of the operational amplifier is connected to the second current setting signal, and the other input terminal of the operational amplifier is connected to the second current sampling resistor. The input terminal of the second gate driver is connected to the voltage setting signal, and the output terminal of the second gate driver is connected to the second switching component.

8. The test circuit for the power device according to claim 1, characterized in that, It also includes a commutation unit connected to the power device under test and configured to adjust the polarity of the power supply provided by the adjustable power supply unit to the power device under test.

9. The test circuit for the power device according to claim 1, characterized in that, The first switching component includes a first switching switch and a second switching switch. The first switching switch is disposed between the power device under test and the first test branch, and the second switching switch is disposed between the power device under test and the second test branch. And / or, The second switching component includes a third switching switch and a fourth switching switch. The third switching switch is disposed between the avalanche energy testing unit and the control terminal of the power device under test, and the fourth switching switch is disposed between the on-resistance testing unit and the control terminal of the power device under test.

10. A testing device for power devices, characterized in that, The test circuit includes the power device according to any one of claims 1-9.

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