Test apparatus and method for dynamic on-resistance of power devices

Abstract

This application relates to a testing apparatus and method for the dynamic on-resistance of a power device. A first voltage source module applies a voltage surge to the power device under test (DUT) when the blocking module is on and the DUT is off. An isolation module isolates the DUT from the voltage surge from the first voltage source module. After the DUT is turned on, a second voltage source module supplies current to the first terminal of the DUT through the isolation module. A voltage sampling module and a current sampling module respectively acquire voltage and current data when the first voltage source module supplies current to the second terminal of the DUT. The obtained voltage and current sampling data can be further used to calculate the dynamic on-resistance of the DUT, thus achieving dynamic on-resistance testing. This method is simple in structure and low in cost.

Description

Technical Field

[0001] This application relates to the field of semiconductor testing technology, and in particular to a testing apparatus and method for the dynamic on-resistance of power devices. Background Technology

[0002] There are two methods for providing the high voltage and high current required for the dynamic Ron (dynamic on-resistance) hard-cut test of GaN power devices: one is based on resistive load, which achieves the purpose of high voltage and high current across the drain and source of the device under test by discharging the resistive load through the energy storage capacitor; the other is based on inductive load and freewheeling branch, which is a circuit composed of inductive load—inductor, freewheeling diode and resistor, which takes advantage of the characteristic that the current / voltage on the inductor does not change abruptly to achieve the purpose of high voltage and high current across the drain and source of the device under test.

[0003] Traditional power device dynamic Ron resistive load hard-cut test schemes require voltage sampling circuits with attenuators that need to attenuate high-voltage signals while maintaining accurate measurement at low voltages, thus meeting the testing requirements of high-voltage clamping and normal low-voltage testing. The drawback of this design is the difficulty in designing the attenuation circuit, resulting in high cost and complex structure. Summary of the Invention

[0004] Therefore, it is necessary to provide a simple and low-cost testing device and method for the dynamic on-resistance of power devices to address the above problems.

[0005] A testing device for the dynamic on-resistance of power devices, comprising:

[0006] The blocking module is connected to the first terminal of the power device under test and is used to block the first terminal of the power device under test from the first voltage source module when it is turned off.

[0007] The first voltage source module is connected to the blocking module and is used to apply a voltage surge to the power device under test when the blocking module is turned on and the power device under test is turned off.

[0008] An isolation module is connected to the first terminal of the power device under test and is used to isolate voltage when the first voltage source module applies a voltage surge to the power device under test.

[0009] The second voltage source module is connected to the isolation module and is used to supply current to the first pole of the power device under test through the isolation module after the power device under test is turned on.

[0010] A voltage sampling module is connected to the isolation module and the second terminal of the power device under test. It is used to collect voltage data when the first voltage source module supplies current to the second terminal of the power device under test.

[0011] A current sampling module is connected to the second terminal of the power device under test, and is used to collect current when the first voltage source module supplies current to the second terminal of the power device under test, so as to obtain current sampling data.

[0012] The voltage sampling data and the current sampling data are used to calculate the dynamic on-resistance of the power device under test; the power device under test includes a first electrode, a second electrode, and a third electrode, and the voltage difference between the third electrode and the second electrode of the power device under test determines the output characteristics between the first electrode and the second electrode of the power device under test.

[0013] In one embodiment, the first voltage source module is further configured to discharge the power device under test when the blocking module is turned on and the power device under test is in a conducting state;

[0014] The voltage sampling module is also used to collect voltage data when the first voltage source module supplies current to the second electrode of the power device under test after the first voltage source module discharges, so as to obtain voltage reference data.

[0015] The current sampling module is also used to collect current when the first voltage source module supplies current to the second electrode of the power device under test after the first voltage source module discharges, so as to obtain current reference data.

[0016] The voltage reference data and the current reference data are used to calculate the reference on-resistance of the power device under test. The reference on-resistance and the dynamic on-resistance of the power device under test are used to analyze whether the power device under test is damaged.

[0017] In one embodiment, the current sampling module includes a non-inductive shunt and a differential sampling circuit. The first end of the non-inductive shunt is connected to the second terminal of the power device under test, the second end of the non-inductive shunt is connected to the first voltage source module, and the differential sampling circuit is connected to the first and second ends of the non-inductive shunt.

[0018] In one embodiment, the testing apparatus further includes:

[0019] A driving circuit is connected to the third terminal of the power device under test and is used to drive the power device under test to switch on and off.

[0020] In one embodiment, the testing apparatus further includes:

[0021] A first current limiting module, wherein the blocking module is connected to the first electrode of the power device under test through the first current limiting module;

[0022] The second current limiting module is connected to the isolation module through the second voltage source module.

[0023] In one embodiment, the first voltage source module includes a high voltage source, an energy storage capacitor C1, and a first protection circuit. The first end of the energy storage capacitor C1 is connected to the positive terminal of the high voltage source and the blocking module, and the second end of the energy storage capacitor C1 is connected to the negative terminal of the high voltage source and the current sampling module. The first protection circuit is connected in parallel with the energy storage capacitor C1 and discharges the energy storage capacitor C1 when it is turned on.

[0024] In one embodiment, the second voltage source module includes a low voltage source, an energy storage capacitor C2, and a second protection circuit. The first end of the energy storage capacitor C2 is connected to the positive terminal of the low voltage source and the second current limiting module, and the second end of the energy storage capacitor C2 is connected to the negative terminal of the low voltage source. The second protection circuit is connected in parallel with the energy storage capacitor C2 and discharges the energy storage capacitor C2 when it is turned on.

[0025] A method for testing the dynamic on-resistance of a power device, comprising:

[0026] The blocking module is turned on, and the drive circuit controls the power device under test to be turned off, so that the first voltage source module applies a voltage surge to the power device under test; the drive circuit is connected to the third terminal of the power device under test, the first voltage source module is connected to the first current limiting module through the blocking module, and the first current limiting module is connected to the first terminal of the power device under test;

[0027] The driving circuit controls the power device under test to conduct, so that the first voltage source module supplies current to the first terminal of the power device under test through the blocking module and the first current limiting module. When the voltage of the first terminal of the power device under test is less than the voltage of the second voltage source module, the second voltage source module supplies current to the first terminal of the power device under test through the second current limiting module and the isolation module. The second current limiting module is connected to the second voltage source module. The isolation module is connected to the first terminal of the power device under test and the second current limiting module.

[0028] The voltage sampling module acquires voltage sampling data; the voltage sampling data is obtained by the voltage sampling module when the first voltage source module supplies current to the second terminal of the power device under test, and the voltage sampling module is connected to the isolation module and the second terminal of the power device under test;

[0029] Acquire current sampling data collected by the current sampling module; the current sampling data is obtained by the current sampling module when the first voltage source module supplies current to the second terminal of the power device under test, and the current sampling module is connected to the second terminal of the power device under test.

[0030] The voltage sampling data and the current sampling data are used to calculate the dynamic on-resistance of the power device under test; the power device under test includes a first electrode, a second electrode, and a third electrode, and the voltage difference between the third electrode and the second electrode of the power device under test determines the output characteristics between the first electrode and the second electrode of the power device under test.

[0031] In one embodiment, the method further includes controlling the blocking module to turn on and controlling the power device under test to be in a turned-off state via the driving circuit, so that the first voltage source module applies a voltage surge to the power device under test before the first voltage source module applies a voltage surge to the power device under test:

[0032] The blocking module is controlled to be turned on, and the power device under test is controlled to be in the on state through the driving circuit, so that the first voltage source module supplies current to the first pole of the power device under test through the blocking module and the first current limiting module. When the voltage of the first pole of the power device under test is less than the voltage of the second voltage source module, the second voltage source module supplies current to the first pole of the power device under test through the second current limiting module and the isolation module.

[0033] The voltage reference data is acquired by the voltage sampling module; the voltage reference data is obtained by the voltage sampling module when the first voltage source module supplies current to the second electrode of the power device under test.

[0034] The current reference data is acquired by the current sampling module; the current reference data is acquired by the current sampling module when the first voltage source module supplies current to the second electrode of the power device under test.

[0035] In one embodiment, before controlling the blocking module to turn on and controlling the power device under test to be in a conducting state via the driving circuit, the method further includes:

[0036] The blocking module is controlled to disconnect, and the energy storage capacitor C1 is charged through the high voltage source; the first voltage source module includes the high voltage source, the energy storage capacitor C1 and the first protection circuit. The first end of the energy storage capacitor C1 is connected to the positive terminal of the high voltage source and the blocking module, and the second end of the energy storage capacitor C1 is connected to the negative terminal of the high voltage source and the current sampling module. The first protection circuit is connected in parallel with the energy storage capacitor C1.

[0037] In one embodiment, after acquiring the current sampling data obtained by the current sampling module, the method further includes:

[0038] The first protection circuit and the second protection circuit are controlled to conduct, so as to discharge the energy storage capacitors C1 and C2; wherein, the second voltage source module includes a low voltage source, the energy storage capacitor C2 and the second protection circuit, the first end of the energy storage capacitor C2 is connected to the positive terminal of the low voltage source and the second current limiting module, the second end of the energy storage capacitor C2 is connected to the negative terminal of the low voltage source, and the second protection circuit is connected in parallel with the energy storage capacitor C2.

[0039] In one embodiment, after acquiring the current sampling data obtained by the current sampling module, the method further includes:

[0040] The dynamic on-resistance of the power device under test is calculated based on the voltage sampling data and the current sampling data.

[0041] The reference on-resistance of the power device under test is calculated based on the voltage reference data and the current reference data.

[0042] Based on the reference on-resistance and dynamic on-resistance of the power device under test, analyze whether the power device under test is damaged.

[0043] The aforementioned test apparatus and method for the dynamic on-resistance of power devices includes a first voltage source module that applies a voltage surge to the power device under test (DUT) when the blocking module is on and the DUT is off. An isolation module isolates the DUT from this voltage surge. After the DUT is turned on, a second voltage source module supplies current to the first terminal of the DUT through the isolation module. Voltage and current sampling modules respectively acquire voltage and current data when the first voltage source module supplies current to the second terminal of the DUT. The obtained voltage and current sampling data can be further used to calculate the dynamic on-resistance of the DUT, thus achieving dynamic on-resistance testing. This method is simple in structure and low in cost. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structural principle of a test device for the dynamic on-resistance of a power device in one embodiment;

[0045] Figure 2 This is a flowchart illustrating a method for testing the dynamic on-resistance of a power device in one embodiment.

[0046] Figure 3 This is a timing diagram for testing the dynamic on-resistance of a power device in one embodiment. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0049] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0050] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0051] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0052] Dynamic Ron (ds) testing needs to be distinguished from static RDS(on). The significant differences between the two are as follows: Dynamic Ron(ds) requires a high-voltage surge before testing to achieve the trapping effect of the two-dimensional electron gas (2DEG) at the drain and source ends of the device under test. After the high-voltage surge, the low-voltage detrapping effect of the 2DEG shows the impedance change between the drain and source of the GaN power device. In general, dynamic Ron(ds) hard-cut testing shows the magnitude of the switching loss of the device under test. The larger the measured dynamic Ron(ds) value, the higher the loss of the GaN power device in high-frequency switching applications, which is less favorable for such applications. Therefore, more and more practitioners have begun to carry out relevant research in the field of dynamic Ron(ds) hard-cut testing.

[0053] Current dynamic Ron resistive load hard-cutting test schemes for power devices are characterized by complex attenuation circuit design, high cost, and intricate structure. The accuracy of these attenuation circuits significantly impacts the accuracy of drain-source voltage (VDS) measurements during dynamic Ron(ds) testing. On one hand, using conventional resistor dividers and oscilloscope attenuation circuits in dynamic Ron(ds) testing requires considering attenuation of high voltage to within the safe voltage range of subsequent circuits, while simultaneously ensuring voltage extraction accuracy during low-voltage testing and avoiding noise and common-mode signal interference. Current attenuation schemes struggle to simultaneously meet signal measurement requirements under both high-voltage and low-voltage conditions; the success or failure of the attenuator design is crucial to the success of VDS measurement. On the other hand, while using dedicated attenuators can address this issue, the design cost is high, and key technological limitations can become a significant obstacle. Furthermore, due to the presence of attenuators, attenuation to below the safe voltage of subsequent circuits under high voltage requires multiple attenuation stages or a large attenuation factor. Parasitic parameters between lines will severely affect its dynamic response characteristics and its voltage extraction accuracy. In addition, multi-stage attenuation requires multiple attenuation circuits, among which the resistance-capacitance matching degree is very high. Even a slight deviation will affect the attenuation accuracy of the entire attenuation circuit and the voltage sampling accuracy of subsequent stages.

[0054] Based on this, this application provides a testing device for the dynamic on-resistance of a power device. When the blocking module is off, it blocks the first terminal of the power device under test (DUT) from the first voltage source module. When the blocking module is on and the DUT is off, the first voltage source module applies a voltage surge to the DUT. The isolation module isolates the DUT from the voltage surge from the first voltage source module. After the DUT is on, the second voltage source module supplies current to the first terminal of the DUT through the isolation module. The voltage sampling module and current sampling module respectively collect voltage and current data when the first voltage source module supplies current to the second terminal of the DUT. The obtained voltage and current sampling data can be further used to calculate the dynamic on-resistance of the DUT. The device has a simple structure and low cost.

[0055] In one embodiment, such as Figure 1As shown, a test device for the dynamic on-resistance of a power device is provided, including a blocking module 110, a first voltage source module 120, an isolation module 130, a second voltage source module 140, a voltage sampling module 150, and a current sampling module 160. The blocking module 110 is connected to the first terminal of the power device under test (DUT), the first voltage source module 120 is connected to the blocking module 110, the isolation module 130 is connected to the first terminal of the power device under test (DUT), the second voltage source module 140 is connected to the isolation module 130, the voltage sampling module 150 is connected to the isolation module 130 and the second terminal of the power device under test (DUT), and the current sampling module 160 is connected to the second terminal of the power device under test (DUT). The blocking module 110 is used to block the first terminal of the power device under test (DUT) from the first voltage source module 120 when it is turned off; the first voltage source module 120 is used to apply a voltage surge to the power device under test (DUT) when the blocking module 110 is turned on and the power device under test (DUT) is turned off; the isolation module 130 is used to isolate the voltage when the first voltage source module 120 applies a voltage surge to the power device under test (DUT); the second voltage source module 140 is used to supply current to the first terminal of the power device under test (DUT) through the isolation module 130 after the power device under test (DUT) is turned on; the voltage sampling module 150 is used to collect voltage data when the first voltage source module 120 supplies current to the second terminal of the power device under test (DUT); and the current sampling module 160 is used to collect current data when the first voltage source module 120 supplies current to the second terminal of the power device under test (DUT).

[0056] Voltage and current sampling data are used to calculate the dynamic on-resistance of the power device under test (DUT). The DUT includes a first terminal, a second terminal, and a third terminal. The voltage difference between the third terminal and the second terminal of the DUT determines the output characteristics between the first and second terminals. The DUT can be a power transistor, such as a GaN power transistor; it can also be other voltage-controlled devices. Taking a power transistor as an example, the first terminal of the DUT is the drain (D), the second terminal is the source (S), and the third terminal is the gate (G). In this embodiment, the DUT is a GaN power transistor.

[0057] Furthermore, the testing device may also include a drive circuit 170, which is connected to the third terminal of the power device under test (DUT) and used to drive the DUT to switch on and off. Specifically, an external controller can be connected to the blocking module 110, voltage sampling module 150, current sampling module 160, and drive circuit 170. The external controller can be a microcontroller or a programmable logic device, which communicates with the testing device and can be used for signal generation and control (not shown in the figures). The external controller controls the switching on and off of the blocking module 110, controls the drive circuit 170 to drive the DUT to switch on and off, and receives voltage sampling data collected by the voltage sampling module 150 and current sampling data collected by the current sampling module 160 to analyze and calculate the dynamic on-resistance of the DUT. In addition, the external controller can also be connected to a first voltage source module 120 and a second voltage source module 140, controlling the first voltage source module 120 to apply a voltage surge to the DUT and controlling the second voltage source module 140 to output current. In this embodiment, the first voltage source module 120 acts as a high-voltage source, generating a large current to apply a voltage surge to the power device under test (DUT). The second voltage source module 140 acts as a low-voltage source, generating a small current, resulting in high voltage accuracy when measured at the isolation module 130. The isolation module 130 provides high-voltage isolation when the first voltage source module 120 applies high voltage to the DUT. When the DUT is conducting, the second voltage source module 140 is connected to the test circuit, thereby enabling voltage measurement across the first and second terminals of the DUT. It can be understood that in other embodiments, the first voltage source module 120 can act as a low-voltage source, generating a small current, while the second voltage source module 140 can act as a high-voltage source, generating a large current, still allowing for dynamic on-resistance testing. Correspondingly, the blocking module 110 must be located on the side of the second voltage source module 140, i.e., on the high-voltage side.

[0058] Taking the first voltage source module 120 as the high-voltage source and the second voltage source module 140 as the low-voltage source as an example, the circuit containing the blocking module 110 and the first voltage source module 120 belongs to the main test circuit, while the circuit containing the isolation module 130, the second voltage source module 140, and the voltage sampling module 150 belongs to the measurement branch circuit. At the start of the test, the blocking module 110 is first turned on, and the drive circuit 170 controls the power device under test (DUT) to be in the off state. Current is supplied to the DUT through the first voltage source module 120, providing a high-voltage surge to the DUT, causing its 2DEG to be trapped and resulting in a current collapse effect. The structure of the blocking module 110 is not unique; it can be a high-voltage relay, a MOS, or an IGBT, or even a GaN device.

[0059] After the high-voltage impulse duration of the device under test (DUT) is set, the drive circuit 170 controls the DUT to conduct, so that the first voltage source module 120 supplies current to the first terminal of the DUT. When the voltage at the first terminal of the DUT is less than the voltage of the second voltage source module 140, the second voltage source module 140 supplies current to the first terminal of the DUT. The current is first supplied to the first terminal of the DUT, and then to the second terminal. The voltage sampling module 150 and the current sampling module 160 can be controlled to perform voltage sampling and current sampling synchronously. The voltage sampling module 150 samples the voltage VDS across the first and second terminals of the DUT during the dynamic Ron(ds) test to obtain voltage sampling data. The voltage sampling module 150 specifically includes sampling unit 1 and sampling unit 2, which respectively sample the voltage at the second terminal of the isolation module 130 and the power device under test (DUT). The voltage sampled by the voltage sampling module 150 from the isolation module 130 in the measurement branch changes with the voltage at the first terminal of the DUT. A constant voltage is provided to the measurement branch using the second voltage source module 140 to form a branch current, so that the voltage sampling module 150 can sample the voltage at the isolation module 130. The current sampling module 160 quantizes the current flowing through the DUT through sampling to obtain current sampling data.

[0060] The isolation module 130 can be composed of two high-voltage isolation diodes with identical parameters from the same batch. For example, the isolation module 130 includes a first diode and a second diode. The cathode of the first diode is connected to the first terminal of the power device under test (DUT), the anode of the first diode is connected to the cathode of the second diode, and the anode of the second diode is connected to the second voltage source module 140.

[0061] The aforementioned test apparatus for the dynamic on-resistance of power devices comprises a first voltage source module 120 that applies a voltage surge to the power device under test (DUT) when the blocking module 110 is on and the DUT is off. An isolation module 130 isolates the DUT from the voltage surge from the first voltage source module 120. After the DUT is turned on, the second voltage source module 140 supplies current to the first terminal of the DUT through the isolation module 130. A voltage sampling module 150 and a current sampling module 160 respectively acquire voltage and current data when the first voltage source module 120 supplies current to the second terminal of the DUT. The obtained voltage and current sampling data can be further used to calculate the dynamic on-resistance of the power device under test, thus achieving dynamic on-resistance testing. This apparatus is simple in structure and low in cost.

[0062] In one embodiment, the first voltage source module 120 is further configured to discharge the power device under test (DUT) when the blocking module 110 is turned on and the DUT is in a conducting state; the voltage sampling module 150 is further configured to perform voltage acquisition when the first voltage source module 120 supplies current to the second terminal of the DUT after the first voltage source module 120 discharges, and obtain voltage reference data; the current sampling module 160 is further configured to perform current acquisition when the first voltage source module 120 supplies current to the second terminal of the DUT after the first voltage source module 120 discharges, and obtain current reference data; the voltage reference data and the current reference data are used to calculate the reference on-resistance of the DUT, and the reference on-resistance and dynamic on-resistance of the DUT are used to analyze whether the DUT is damaged.

[0063] Specifically, before applying a voltage surge to the power device under test (DUT), the drive circuit 170 controls the DUT to be in an on-state and controls the blocking module 110 to be turned on, connecting the first voltage source module 120 to the DUT. The first voltage source module 120 supplies current to the first terminal of the DUT. When the voltage at the first terminal of the DUT is less than the voltage of the second voltage source module 140, the second voltage source module 140 supplies current to the first terminal of the DUT. When the first voltage source module 120 supplies current to the second terminal of the DUT, voltage reference data and current reference data are collected by the voltage sampling module 150 and current sampling module 160, respectively. Based on the voltage and current reference data, the reference on-resistance of the DUT can be calculated. After determining the dynamic on-resistance of the DUT in subsequent tests, the reference on-resistance and the dynamic on-resistance can be compared. The relationship between the two can determine whether the device is damaged.

[0064] Furthermore, in one embodiment, the testing device further includes a first current-limiting module 180 and a second current-limiting module 190. The blocking module 110 is connected to the first terminal of the power device under test (DUT) through the first current-limiting module 180; the second voltage source module 140 is connected to the isolation module 130 through the second current-limiting module 190. The first current-limiting module 180 includes a resistor R1, which can be a current-limiting resistor matrix or a single resistor. The second current-limiting module 190 includes a resistor R2, which can also be a current-limiting resistor matrix or a single resistor. An external controller can be connected to the first current-limiting module 180 and the second current-limiting module 190 to adjust the resistance values ​​of R1 and R2 as needed, thereby regulating the current supplied to the DUT. Specifically, the first current-limiting module 180 and the second current-limiting module 190 can provide an adjustable current of 0–10A, which can be extended to 0–30A.

[0065] It is understood that the specific structures of the first voltage source module 120, the second voltage source module 140, and the current sampling module 160 are not unique. In one embodiment, such as... Figure 1 As shown, the first voltage source module 120 includes a high-voltage source V1, an energy storage capacitor C1, and a first protection circuit 122. The first terminal of the energy storage capacitor C1 is connected to the positive terminal of the high-voltage source V1 and the blocking module 110, while the second terminal of the energy storage capacitor C1 is connected to the negative terminal of the high-voltage source V1 and the current sampling module 160. The first protection circuit 122 is connected in parallel with the energy storage capacitor C1 and discharges the energy storage capacitor C1 when it is turned on. The energy storage capacitor C1 can be an energy storage capacitor matrix or a single capacitor. An external controller can be connected to the high-voltage source V1 and the first protection circuit 122 to control the charging of the energy storage capacitor C1 by the high-voltage source V1 and to control the on / off state of the first protection circuit 122.

[0066] Furthermore, the second voltage source module 140 may include a low-voltage source V2, an energy storage capacitor C2, and a second protection circuit 142. The first terminal of the energy storage capacitor C2 is connected to the positive terminal of the low-voltage source V2 and the second current-limiting module 190, and the second terminal of the energy storage capacitor C2 is connected to the negative terminal of the low-voltage source V2. The second protection circuit 142 is connected in parallel with the energy storage capacitor C2 and discharges the energy storage capacitor C2 when it is turned on. Similarly, the energy storage capacitor C2 can be an energy storage capacitor matrix or a single capacitor. An external controller can be connected to the low-voltage source V2 and the second protection circuit 142 to control the charging of the energy storage capacitor C2 by the low-voltage source V2 and to control the switching on and off of the second protection circuit 142.

[0067] Furthermore, in one embodiment, reference continues to be made to... Figure 1The current sampling module 160 includes a non-inductive shunt R3 and a differential sampling circuit 162. The first terminal of the non-inductive shunt R3 is connected to the second terminal of the power device under test (DUT), and the second terminal of the non-inductive shunt R3 is connected to the first voltage source module 120, specifically, it can be connected to the negative terminal of the high-voltage source V1. The differential sampling circuit 162 is connected to both the first and second terminals of the non-inductive shunt R3. The differential sampling circuit 162 can be connected to an external controller to receive the acquired current data.

[0068] Specifically, at the start of the test, the blocking module 110 is first disconnected, and the energy storage capacitor C1 is charged for a preset time through the high-voltage source V1. Then, the blocking module 110 is turned on, and the power device under test (DUT) is controlled to be in a conducting state through the drive circuit 170 for reference on-resistance testing. After the dynamic on-resistance test is completed, the first protection circuit 122 and the second protection circuit 142 are turned on to discharge the energy storage capacitors C1 and C2.

[0069] In one embodiment, such as Figure 2 As shown, a method for testing the dynamic on-resistance of power devices is also provided, including:

[0070] Step S100: Control the blocking module to turn on, and control the power device under test to be in the off state through the driving circuit, so that the first voltage source module can apply a voltage surge to the power device under test. The driving circuit is connected to the third terminal of the power device under test, the first voltage source module is connected to the first current limiting module through the blocking module, and the first current limiting module is connected to the first terminal of the power device under test.

[0071] Step S200: The drive circuit controls the power device under test (DUT) to conduct, so that the first voltage source module supplies current to the first terminal of the DUT through the blocking module and the first current limiting module. When the voltage of the first terminal of the DUT is less than the voltage of the second voltage source module, the second voltage source module supplies current to the first terminal of the DUT through the second current limiting module and the isolation module. The second current limiting module is connected to the second voltage source module; the isolation module is connected to the first terminal of the DUT and the second current limiting module.

[0072] Step S300: Acquire the voltage sampling data collected by the voltage sampling module. The voltage sampling data is obtained by the voltage sampling module when the first voltage source module supplies current to the second terminal of the power device under test. The voltage sampling module is connected to the isolation module and the second terminal of the power device under test.

[0073] Step S400: Acquire the current sampling data collected by the current sampling module. The current sampling data is obtained by the current sampling module when the first voltage source module supplies current to the second terminal of the power device under test. The current sampling module is connected to the second terminal of the power device under test.

[0074] Among them, voltage sampling data and current sampling data are used to calculate the dynamic on-resistance of the power device under test; the power device under test includes a first terminal, a second terminal and a third terminal, and the voltage difference between the third terminal and the second terminal of the power device under test determines the output characteristics between the first terminal and the second terminal of the power device under test.

[0075] In one embodiment, prior to step S100, the method further includes:

[0076] The control blocking module is turned on, and the drive circuit controls the power device under test to be in the on state, so that the first voltage source module delivers current to the first pole of the power device under test through the blocking module and the first current limiting module. When the voltage of the first pole of the power device under test is less than the voltage of the second voltage source module, the second voltage source module delivers current to the first pole of the power device under test through the second current limiting module and the isolation module.

[0077] The voltage reference data is acquired by the voltage sampling module. This voltage reference data is obtained by the voltage sampling module when current is supplied from the first voltage source module to the second terminal of the power device under test.

[0078] The current reference data is acquired by the current sampling module. This current reference data is obtained by the current sampling module when the first voltage source module supplies current to the second terminal of the power device under test.

[0079] In one embodiment, before controlling the blocking module to be on and controlling the power device under test to be in the on state through the driving circuit, the method further includes: controlling the blocking module to be off and charging the energy storage capacitor C1 through a high-voltage source. The first voltage source module includes a high-voltage source, an energy storage capacitor C1, and a first protection circuit. The first terminal of the energy storage capacitor C1 is connected to the positive terminal of the high-voltage source and the blocking module, the second terminal of the energy storage capacitor C1 is connected to the negative terminal of the high-voltage source and the current sampling module, and the first protection circuit is connected in parallel with the energy storage capacitor C1.

[0080] In one embodiment, after acquiring the current sampling data collected by the current sampling module, the method further includes: controlling the first protection circuit and the second protection circuit to conduct, so as to discharge the energy storage capacitors C1 and C2. The second voltage source module includes a low-voltage source, the energy storage capacitor C2, and the second protection circuit. The first terminal of the energy storage capacitor C2 is connected to the positive terminal of the low-voltage source and the second current limiting module, and the second terminal of the energy storage capacitor C2 is connected to the negative terminal of the low-voltage source. The second protection circuit is connected in parallel with the energy storage capacitor C2.

[0081] In one embodiment, after acquiring the current sampling data collected by the current sampling module, the method further includes: calculating the dynamic on-resistance of the power device under test based on the voltage sampling data and the current sampling data; calculating the reference on-resistance of the power device under test based on the voltage reference data and the current reference data; and analyzing whether the power device under test is damaged based on the reference on-resistance and the dynamic on-resistance of the power device under test.

[0082] It is understood that the specific implementation method of the above-mentioned test method for the dynamic on-resistance of power devices has been explained in detail in the above-mentioned test device for the dynamic on-resistance of power devices, and will not be repeated here.

[0083] Specifically, such as Figure 1 As shown, the power device dynamic on-resistance testing device provided in this application includes a blocking module 110, a first voltage source module 120, an isolation module 130, a second voltage source module 140, a voltage sampling module 150, a current sampling module 160, a drive circuit 170, a first current limiting module 180, and a second current limiting module 190. The high-voltage isolation diode used in the isolation module 130 is specifically a fast recovery high-voltage isolation diode, and its junction capacitance should be as small as possible. The measurement branch composed of the second voltage source module 140, the second current limiting module 190, the isolation module 130, and the voltage sampling module 150 can be interchanged with the test main circuit composed of the first voltage source module 120, the blocking module 110, and the first current limiting module 180. The output current of the measurement branch can be large or small, while the output current of the test main circuit remains the same; the specific choice depends on actual needs. Simultaneously, the ground terminals of the high-voltage source V1 in the test main circuit and the low-voltage source V2 in the measurement branch must be well connected.

[0084] The dynamic on-resistance test of power devices is specifically divided into the following stages:

[0085] A. The first stage involves controlling the blocking module 110 to isolate the first voltage source module 120 from the power device under test (DUT). Simultaneously, based on the set output voltage VDS and output current IDS, the current-limiting resistor matrix connection values ​​in the main test circuit are set, ensuring the current relationship between the main test circuit and the measurement branch is at least 0.001 times. Alternatively, the main test circuit current is 0.001 times IDS, the measurement branch current is IDS, and the resistance values ​​of resistors R1 and R2 in the connection circuit are controlled according to the relevant voltage magnitudes.

[0086] B. In the second stage, the power device under test (DUT) is controlled to be in the on state by the drive circuit 170, and the energy storage capacitor C1 is charged for a period of time by the high voltage source V1.

[0087] C. In the third stage, the control blocking module 110 connects the first voltage source module 120 to the power device under test (DUT). At this time, the energy storage capacitor C1 discharges to the resistor R1 and the power device under test (DUT). The current flowing through the power device under test (DUT) is I1. When the voltage between the drain and source of the power device under test (DUT) is less than the voltage of the low-voltage source V2 in the measurement branch, the measurement branch will be connected to the test circuit, thereby realizing the measurement of the voltage VDS0 between the drain and source of the power device under test (DUT). At the same time, the current sampling module 160 starts to work and samples the magnitude of the current flowing through the power device under test (DUT) to obtain I1'.

[0088] D. In the fourth stage, after the third stage has been executed for a period of time, the power device under test (DUT) is controlled to be in the off state. At the same time, the high voltage source V1 charges the energy storage capacitor C1 and reaches the target set voltage value VDS through the energy storage capacitor C1. During the charging process of the high voltage source V1 on the energy storage capacitor C1, the voltage between the drain and source of the power device under test (DUT) increases with the increase of the voltage on the energy storage capacitor C1, thereby realizing the generation of 2DEG high voltage trapping.

[0089] E. Fifth Stage: After the high-voltage device under test (DUT) is subjected to an impulse for a period of time, the control drive circuit 170 turns on the DUT. The energy storage capacitor C1 discharges through the resistor R1 and the DUT to generate a large current, achieving low-voltage decapsulation. The current flowing through the DUT is I2. When the voltage between the drain and source of the DUT is less than the voltage of the low-voltage source V2 in the measurement branch, the measurement branch will be connected to the test circuit, thereby realizing the measurement of the drain-source voltage VDS1 of the DUT. At the same time, the current sampling module 160 starts working to sample the current flowing through the DUT and obtain I2'.

[0090] F. Sixth stage: The control blocking module 110 disconnects the first voltage source module 120 and the power device under test (DUT). By connecting the first protection circuit 122 and the second protection circuit 142, the voltage on the energy storage capacitors C1 and C2 is discharged, and the power device under test (DUT) is turned off by the drive circuit 170.

[0091] Test timing as follows Figure 3 As shown, t0 to t1 represents the first stage, t1 to t2 represents the second stage, t2 to t3 represents the third stage, t3 to t4 represents the fourth stage, t4 to t6 represents the fifth stage, and t6 onwards represents the sixth stage. VG represents the gate drive output voltage of the power device under test (DUT), I represents the current flowing through the DUT, and V represents the drain-source voltage of the DUT.

[0092] The magnitude and accuracy of the drain-source voltage of the power measurement device (DUT) are determined by sampling unit 1 and sampling unit 2. Specifically, the drain-source voltage VDS0 = V 采样10 -V 采样20 The drain-source voltage VDS1 = V 采样11 -V 采样21 , where V 采样10 and V 采样11 V was acquired by sampling unit 1. 采样20 and V 采样21 It was collected by sampling unit 2.

[0093] The formula for calculating the reference on-resistance of the power device under test (DUT) is: R = VDS0 / I1', and the formula for calculating the dynamic Ron(ds) of the DUT is: Ron(ds) = VDS1 / I2'. By comparing the relationship between the reference on-resistance R and the dynamic Ron(ds), it can be determined whether the device is damaged.

[0094] The power device dynamic on-resistance testing apparatus provided in this application can output large or small currents in both the measurement branch and the main test circuit, without simultaneously outputting large currents. The consistency of the isolation diodes in the isolation module 130 can be avoided and optimized through a calibration scheme, theoretically achieving a voltage measurement accuracy of less than 1%. This testing apparatus has a simple structure and low cost. Utilizing the isolation module 130, resistors, capacitors, and voltage sources significantly reduces the complexity of the test circuit, thereby lowering its cost to some extent. Since no attenuation circuit is used, the frequency of the parasitic capacitance-limited passband signal in the circuit is greatly expanded, broadening the application scope of this solution and improving its response speed, thus meeting the measurement requirements of dynamic Ron(ds) for GaN power devices.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A testing device for the dynamic on-resistance of a power device, characterized in that, include: The blocking module is connected to the first terminal of the power device under test and is used to block the first terminal of the power device under test from the first voltage source module when it is turned off. The first voltage source module is connected to the blocking module and is used to apply a voltage surge to the power device under test when the blocking module is turned on and the power device under test is turned off. An isolation module is connected to the first terminal of the power device under test and is used to isolate voltage when the first voltage source module applies a voltage surge to the power device under test. The second voltage source module is connected to the isolation module and is used to supply current to the first pole of the power device under test through the isolation module after the power device under test is turned on. A voltage sampling module is connected to the isolation module and the second terminal of the power device under test. It is used to collect voltage data when the first voltage source module supplies current to the second terminal of the power device under test. A current sampling module is connected to the second terminal of the power device under test, and is used to collect current when the first voltage source module supplies current to the second terminal of the power device under test, so as to obtain current sampling data. The voltage sampling data and the current sampling data are used to calculate the dynamic on-resistance of the power device under test (DUT). The DUT includes a first terminal, a second terminal, and a third terminal. The voltage difference between the third terminal and the second terminal of the DUT determines the output characteristics between the first and second terminals of the DUT. The current sampling module includes a non-inductive shunt and a differential sampling circuit. The first terminal of the non-inductive shunt is connected to the second terminal of the DUT, and the second terminal of the non-inductive shunt is connected to the first voltage source module. The differential sampling circuit connects the first and second terminals of the non-inductive shunt. The testing apparatus also includes: A first current limiting module, wherein the blocking module is connected to the first electrode of the power device under test through the first current limiting module; The second current limiting module is connected to the isolation module through the second voltage source module.

2. The testing apparatus according to claim 1, characterized in that, The first voltage source module is also used to discharge the power device under test when the blocking module is turned on and the power device under test is in the on state; The voltage sampling module is also used to collect voltage data when the first voltage source module supplies current to the second electrode of the power device under test after the first voltage source module discharges, so as to obtain voltage reference data. The current sampling module is also used to collect current when the first voltage source module supplies current to the second electrode of the power device under test after the first voltage source module discharges, so as to obtain current reference data. The voltage reference data and the current reference data are used to calculate the reference on-resistance of the power device under test. The reference on-resistance and the dynamic on-resistance of the power device under test are used to analyze whether the power device under test is damaged.

3. The testing apparatus according to claim 1, characterized in that, Also includes: A driving circuit is connected to the third terminal of the power device under test and is used to drive the power device under test to switch on and off.

4. The testing apparatus according to claim 1, characterized in that, The first voltage source module includes a high voltage source, an energy storage capacitor C1, and a first protection circuit. The first end of the energy storage capacitor C1 is connected to the positive terminal of the high voltage source and the blocking module, and the second end of the energy storage capacitor C1 is connected to the negative terminal of the high voltage source and the current sampling module. The first protection circuit is connected in parallel with the energy storage capacitor C1 and discharges the energy storage capacitor C1 when it is turned on.

5. The testing apparatus according to claim 1, characterized in that, The second voltage source module includes a low voltage source, an energy storage capacitor C2, and a second protection circuit. The first end of the energy storage capacitor C2 is connected to the positive terminal of the low voltage source and the second current limiting module, and the second end of the energy storage capacitor C2 is connected to the negative terminal of the low voltage source. The second protection circuit is connected in parallel with the energy storage capacitor C2 and discharges the energy storage capacitor C2 when it is turned on.

6. A method for testing the dynamic on-resistance of a power device, characterized in that, include: The blocking module is turned on, and the drive circuit controls the power device under test to be turned off, so that the first voltage source module applies a voltage surge to the power device under test; the drive circuit is connected to the third terminal of the power device under test, the first voltage source module is connected to the first current limiting module through the blocking module, and the first current limiting module is connected to the first terminal of the power device under test; The driving circuit controls the power device under test to conduct, so that the first voltage source module supplies current to the first terminal of the power device under test through the blocking module and the first current limiting module. When the voltage of the first terminal of the power device under test is less than the voltage of the second voltage source module, the second voltage source module supplies current to the first terminal of the power device under test through the second current limiting module and the isolation module. The second current limiting module is connected to the second voltage source module. The isolation module is connected to the first terminal of the power device under test and the second current limiting module. The voltage sampling module acquires voltage sampling data; the voltage sampling data is obtained by the voltage sampling module when the first voltage source module supplies current to the second terminal of the power device under test, and the voltage sampling module is connected to the isolation module and the second terminal of the power device under test; Acquire the current sampling data obtained by the current sampling module; The current sampling data is obtained by the current sampling module when the first voltage source module supplies current to the second terminal of the power device under test. The current sampling module is connected to the second terminal of the power device under test. The voltage sampling data and the current sampling data are used to calculate the dynamic on-resistance of the power device under test (DUT). The DUT includes a first terminal, a second terminal, and a third terminal. The voltage difference between the third terminal and the second terminal of the DUT determines the output characteristics between the first and second terminals of the DUT. The current sampling module includes a non-inductive shunt and a differential sampling circuit. The first terminal of the non-inductive shunt is connected to the second terminal of the DUT, and the second terminal of the non-inductive shunt is connected to the first voltage source module. The differential sampling circuit is connected to the first and second terminals of the non-inductive shunt.

7. The test method according to claim 6, characterized in that, The method of controlling the blocking module to turn on and controlling the power device under test to be in a turned-off state through the driving circuit, so that the first voltage source module applies a voltage surge to the power device under test, further includes: The blocking module is controlled to be turned on, and the power device under test is controlled to be in the on state through the driving circuit, so that the first voltage source module supplies current to the first pole of the power device under test through the blocking module and the first current limiting module. When the voltage of the first pole of the power device under test is less than the voltage of the second voltage source module, the second voltage source module supplies current to the first pole of the power device under test through the second current limiting module and the isolation module. The voltage reference data is acquired by the voltage sampling module; the voltage reference data is obtained by the voltage sampling module when the first voltage source module supplies current to the second electrode of the power device under test. The current reference data is acquired by the current sampling module; the current reference data is acquired by the current sampling module when the first voltage source module supplies current to the second electrode of the power device under test.

8. The test method according to claim 7, characterized in that, Before controlling the blocking module to conduct and controlling the power device under test to be in the conducting state through the driving circuit, the method further includes: The blocking module is controlled to disconnect, and the energy storage capacitor C1 is charged through the high voltage source; the first voltage source module includes the high voltage source, the energy storage capacitor C1 and the first protection circuit. The first end of the energy storage capacitor C1 is connected to the positive terminal of the high voltage source and the blocking module, and the second end of the energy storage capacitor C1 is connected to the negative terminal of the high voltage source and the current sampling module. The first protection circuit is connected in parallel with the energy storage capacitor C1.

9. The test method according to claim 8, characterized in that, After acquiring the current sampling data obtained by the current sampling module, the method further includes: The first protection circuit and the second protection circuit are controlled to conduct, so as to discharge the energy storage capacitors C1 and C2; wherein, the second voltage source module includes a low voltage source, the energy storage capacitor C2 and the second protection circuit, the first end of the energy storage capacitor C2 is connected to the positive terminal of the low voltage source and the second current limiting module, the second end of the energy storage capacitor C2 is connected to the negative terminal of the low voltage source, and the second protection circuit is connected in parallel with the energy storage capacitor C2.

10. The test method according to claim 7, characterized in that, After acquiring the current sampling data obtained by the current sampling module, the method further includes: The dynamic on-resistance of the power device under test is calculated based on the voltage sampling data and the current sampling data. The reference on-resistance of the power device under test is calculated based on the voltage reference data and the current reference data. Based on the reference on-resistance and dynamic on-resistance of the power device under test, analyze whether the power device under test is damaged.

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