Device and method for testing the 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. A discharge module releases the residual voltage on the DUT after the voltage surge from the first voltage source module. A second voltage source module supplies current to the first terminal of the DUT through the isolation module after the DUT is on. 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 data can be further used to calculate the dynamic on-resistance of the DUT. The 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 discharge module is connected to the first terminal of the power device under test and is used to release the residual voltage of the power device under test after the first voltage source module completes the voltage surge.

[0010] 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.

[0011] 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.

[0012] A current sampling module is connected to the second terminal of the power device under test, and is used to collect current data when the first voltage source module supplies current to the second terminal of the power device under test.

[0013] The voltage data and the current 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.

[0014] In one embodiment, the isolation module includes an isolation diode D1 and an isolation diode D2, the cathode of the isolation diode D1 is connected to the first terminal of the power device under test, the anode of the isolation diode D1 is connected to the cathode of the isolation diode D2, and the anode of the isolation diode D2 is connected to the second voltage source module.

[0015] The voltage data includes the cathode voltage of the isolation diode D2, the anode voltage of the isolation diode D2, and the voltage of the second terminal of the power device under test.

[0016] In one embodiment, the testing apparatus further includes:

[0017] 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.

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

[0019] 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;

[0020] The second current limiting module is connected to the isolation module through the second voltage source module.

[0021] In one embodiment, the first current limiting module and / or the second current limiting module is a programmable resistor matrix.

[0022] In one embodiment, the first voltage source module includes a high voltage source and an energy storage capacitor C1. 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.

[0023] In one embodiment, the second voltage source module includes a low voltage source and an energy storage capacitor C2. 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.

[0024] A method for testing the dynamic on-resistance of a power device, comprising:

[0025] The control blocking module is turned on, the discharge module is turned off, and the drive circuit controls the power device under test to be in a turned-off state so that the first voltage source module can apply 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 discharge module is connected to the first 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;

[0026] 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.

[0027] The voltage data is acquired by the voltage sampling module; the voltage data is acquired 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;

[0028] Acquire current data collected by the current sampling module; the current data is collected 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.

[0029] The voltage data and the current 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.

[0030] In one embodiment, the control blocking module is turned on, the discharge module is turned off, and the power device under test is controlled to be in a turned-off state through the drive circuit, so that after the first voltage source module applies a voltage surge to the power device under test, the system further includes:

[0031] The blocking module is turned off and the discharge module is turned on, so that the discharge module can release the residual voltage of the power device under test;

[0032] After controlling the power device under test to conduct through the driving circuit, the method further includes: controlling the blocking module to conduct and turning off the discharge module.

[0033] In one embodiment, after the control blocking module is turned on, the discharge module is turned off, and the power device under test is controlled to be in a turned-off state through the drive circuit, the method further includes: charging the energy storage capacitor C1 through a high voltage source; wherein, the first voltage source module includes a high voltage source and an energy storage capacitor C1, 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.

[0034] In one embodiment, after acquiring the current data obtained by the current sampling module, the method further includes:

[0035] The control blocking module is turned on, the discharge module is turned off, and the power device under test is controlled to be in a turned-off state through the drive circuit, so that the first voltage source module performs voltage impact on the power device under test until the preset number of consecutive tests are completed.

[0036] 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 the voltage surge from the first voltage source module. A discharge module releases the residual voltage on the DUT after the voltage surge from the first voltage source module. A second voltage source module supplies current to the first terminal of the DUT through the isolation module after the DUT is on. Voltage and current sampling modules acquire voltage and current data respectively when the first voltage source module supplies current to the second terminal of the DUT. The obtained voltage and current data can be further used to calculate the dynamic on-resistance of the DUT. The method is simple in structure and low in cost. Attached Figure Description

[0037] 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;

[0038] Figure 2 This is a flowchart illustrating a method for testing the dynamic on-resistance of a power device in one embodiment.

[0039] Figure 3 This is a schematic diagram of a hard-cut test of the dynamic on-resistance of a power device in one embodiment;

[0040] Figure 4 This is a schematic diagram of a soft-switching test of the dynamic on-resistance of a power device in one embodiment;

[0041] Figure 5 This is a timing diagram for a hard-cut discontinuity test of the dynamic on-resistance of a power device in one embodiment;

[0042] Figure 6 This is a timing diagram for a hard-cut continuous test of the dynamic on-resistance of a power device in one embodiment;

[0043] Figure 7 This is a timing diagram for a soft-cut discontinuity test of the dynamic on-resistance of a power device in one embodiment.

[0044] Figure 8 This is a timing diagram for a soft-switching continuous test of the dynamic on-resistance of a power device in one embodiment. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Based on this, this application provides a testing device for the dynamic on-resistance of a power device. The blocking module blocks the first terminal of the power device under test (DUT) from the first voltage source module when it is off. 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. The discharge module releases the residual voltage of the DUT after the voltage surge from the first voltage source module. When 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 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 data can be further used to calculate the dynamic on-resistance of the DUT. The device has a simple structure and low cost.

[0053] In one embodiment, such as Figure 1 As 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, a current sampling module 160, and a discharge module 200. 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 DUT. The discharge module 200 is also connected to the first terminal of the DUT. The second voltage source module 140 is connected to the isolation module 130. The voltage sampling module 150 is connected to both the isolation module 130 and the second terminal of the DUT. The current sampling module 160 is connected to the second terminal of the 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 impulse 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 impulse to the power device under test (DUT); the discharge module 200 is used to release the residual voltage of the power device under test (DUT) after the first voltage source module 120 completes the voltage impulse; 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).

[0054] Voltage and current 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.

[0055] 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, the discharging module 200, the voltage sampling module 150, the current sampling module 160, and the 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 accompanying drawings). The external controller controls the switching on and off of the blocking module 110 and the discharging module 200, controls the drive circuit 170 to drive the DUT to switch on and off, and receives voltage data collected by the voltage sampling module 150 and current 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.

[0056] 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, the discharge module 200 is turned off, 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 and can be configured according to timing requirements. Specifically, the blocking module 110 can be a high-voltage relay, MOS, or IGBT, or it can be a GaN device.

[0057] 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 data. The voltage sampling module 150 may specifically include sampling unit 1, sampling unit 2, and sampling unit 3. It samples 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 second voltage source module 140 provides a constant voltage to the measurement branch, thereby forming a branch current, so that the voltage sampling module 150 can sample the voltage at the isolation module 130.

[0058] The current sampling module 160 samples and quantizes the current flowing through the power device under test (DUT) to obtain current data. The current sampling module 160 may include 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 is connected to the first voltage source module 120. The differential sampling circuit is connected to both terminals of the non-inductive shunt. The differential sampling circuit can be connected to an external controller to receive the acquired current data.

[0059] The isolation module 130 can be composed of two high-voltage isolation diodes with identical parameters from the same batch. For example, isolation module 130 includes isolation diodes D1 and D2. The cathode of isolation diode D1 is connected to the first terminal of the power device under test (DUT), the anode of isolation diode D1 is connected to the cathode of isolation diode D2, and the anode of isolation diode D2 is connected to the second voltage source module 140. In the voltage sampling module 150, sampling unit 1 is connected to the anode of isolation diode D1, sampling unit 2 is connected to the anode of isolation diode D2, and sampling unit 3 is connected to the second terminal of the DUT. The voltage data includes the cathode voltage of isolation diode D2, the anode voltage of isolation diode D2, and the voltage at the second terminal of the DUT.

[0060] Furthermore, after the first voltage source module 120 applies a voltage surge to the power device under test (DUT), it also controls the blocking module 110 to turn off and the discharge module 200 to turn on, so that the discharge module 200 can release the residual voltage of the DUT. Specifically, when the blocking module 110 blocks the high-voltage side from the DUT, the discharge module 200 releases the residual voltage at the drain of the DUT, completing the soft-switching environment setup. After the residual voltage release is completed, the drive circuit 170 controls the DUT to turn on, then controls the blocking module 110 to turn on, and finally turns off the discharge module 200. The specific type of the discharge module 200 is not unique and can be selected according to timing requirements. For example, the discharge module 200 can be a relay, or a MOSFET, IGBT, or GaN device, etc.

[0061] The aforementioned test apparatus for the dynamic on-resistance of power devices includes 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 by the first voltage source module 120. A discharge module 200 releases the residual voltage of the DUT after the voltage surge by the first voltage source module 120. A second voltage source module 140 supplies current to the first terminal of the DUT through the isolation module 130 after the DUT is turned on. A voltage sampling module 150 and a current sampling module 160 acquire voltage and current data respectively when the first voltage source module 120 supplies current to the second terminal of the DUT. The obtained voltage and current data can be further used to calculate the dynamic on-resistance of the DUT. The apparatus is simple in structure and low in cost.

[0062] Furthermore, in one embodiment, the testing apparatus 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) via the first current-limiting module 180; the second voltage source module 140 is connected to the isolation module 130 via the second current-limiting module 190. The first current-limiting module 180 includes a resistor R1, which can be a programmable resistor matrix or a single resistor. The second current-limiting module 190 includes a resistor R2, which can also be a programmable 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.

[0063] It is understood that the specific structures of the first voltage source module 120 and the second voltage source module 140 are not unique. In one embodiment, such as... Figure 1 As shown, the first voltage source module 120 includes a high-voltage source V1 and an energy storage capacitor C1. 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 is connected to the negative terminal of the high-voltage source V1 and the current sampling module 160. 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 to control the charging of the energy storage capacitor C1. Specifically, at the start of the test, the blocking module 110 is first disconnected, the discharge module 200 is turned off, and the drive circuit 170 controls the power device under test (DUT) to be in a turned-off state. The high-voltage source V1 charges the energy storage capacitor C1 for a preset time to prepare for subsequent high-voltage surges. The first voltage source module 120 may also include a high-voltage protection circuit connected in parallel with the energy storage capacitor C1. When the circuit is on, the high-voltage protection circuit discharges the energy storage capacitor C1. An external controller can be connected to the high-voltage protection circuit to control its on / off state.

[0064] Furthermore, the second voltage source module 140 includes a low-voltage source V2 and an energy storage capacitor C2. 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. 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 to control the charging of the energy storage capacitor C2. The second voltage source module 140 may also include a low-voltage protection circuit, which is connected in parallel with the energy storage capacitor C2 and discharges the energy storage capacitor C2 when it is turned on. An external controller can be connected to the low-voltage protection circuit to control its on / off state.

[0065] Furthermore, after completing one voltage and current data test, the blocking module 110 can be turned on again, the discharging module 700 can be turned off, and the power device under test (DUT) can be controlled to be in a turned-off state through the drive circuit 170. The first voltage source module 120 then applies a voltage surge to the DUT again until a preset number of consecutive tests are completed, such as two or more. The dynamic on-resistance can be calculated by averaging the voltage and current data obtained from multiple consecutive tests, or by removing abnormal data from the voltage and current data and then averaging them to calculate the dynamic on-resistance. Combining voltage and current data from multiple tests to analyze the dynamic on-resistance provides higher accuracy.

[0066] In one embodiment, such as Figure 2 As shown, a method for testing the dynamic on-resistance of power devices is also provided, including:

[0067] Step S100: The blocking module is turned on, the bleeder module is turned off, and the power device under test is controlled to be in the off state through the drive circuit, 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 bleeder module is connected to the first 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.

[0068] 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, and the isolation module is connected to the first terminal of the DUT and the second current limiting module.

[0069] Step S300: Acquire the voltage data collected by the voltage sampling module. The voltage data is acquired 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.

[0070] Step S400: Acquire the current data collected by the current sampling module. The current data is collected 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.

[0071] Among them, voltage and current 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.

[0072] In one embodiment, after step S100, the method further includes: controlling the blocking module to turn off and the discharging module to turn on, so that the discharging module releases the residual voltage of the power device under test. After controlling the power device under test to turn on through the driving circuit in step S200, the method further includes: controlling the blocking module to turn on and turning off the discharging module.

[0073] In one embodiment, after controlling the blocking module to be turned on, the discharging module to be turned off, and the power device under test to be turned off through the driving circuit in step S100, the method further includes: charging the energy storage capacitor C1 through a high-voltage source. The first voltage source module includes a high-voltage source and an energy storage capacitor C1. The first terminal of the energy storage capacitor C1 is connected to the positive terminal of the high-voltage source and the blocking module, and 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.

[0074] In one embodiment, after step S400, the method further includes: returning to step S100 until a preset number of consecutive tests are completed.

[0075] 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.

[0076] 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, a second current limiting module 190, and a discharge module 200. The isolation module 130 uses a high-voltage isolation diode, and its recovery time is shorter than the turn-on time of the power device under test (DUT). 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 should have a lower operating current than the main test circuit composed of the first voltage source module 120, the blocking module 110, and the first current limiting module 180, specifically in a certain proportional relationship. Simultaneously, the ground terminals of the high-voltage source V1 in the main test circuit and the low-voltage source V2 in the measurement branch should be well connected. Furthermore, the resistive load used in the first current limiting module 180 and the second current limiting module 190 can be replaced with an inductive load.

[0077] The dynamic on-resistance test of power devices is specifically divided into hard-cut test and soft-cut test, as follows:

[0078] like Figure 3 As shown, the hard-cut test is divided into the following stages:

[0079] A. In the first stage, the switching devices in the control blocking module 110 are always in the on state, while the control discharge module 200 is in the normally off state. The discharge module 200 is not limited to MOSFETs, but can also be switching devices such as IGBTs. Afterwards, the high-voltage source V1 charges the energy storage capacitor C1 to reach the target set voltage value. 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 achieving 2DEG high-voltage trapping. In this stage, the power device under test (DUT) is in the off state, the high-voltage protection circuit is not connected to the circuit, and the resistor R1 is connected to the circuit. Its resistance value is determined by the set output current IDS and voltage VDS.

[0080] B. In the second stage of the hard-cut test logic, after the high voltage needs to impact the power device under test (DUT) for a period of time, the control drive circuit 170 will turn on the DUT. The energy storage capacitor C1 discharges the resistor R1 and the DUT to generate a large current to achieve low-voltage decapsulation. When the drain voltage 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 VDS of the DUT. At the same time, the current sampling module 160 starts to work and samples the current flowing through the DUT.

[0081] C. After the first and second stages are completed, the hard-cut test will be mainly divided into continuous test and discontinuous test. During the continuous test, the relevant operations of the first and second stages are repeated. The high voltage source V1 and the low voltage source V2 will continuously charge the energy storage capacitors C1 and C2. During the discontinuous test, the test will directly enter the third stage.

[0082] D. In the third stage, the high voltage protection circuit and the low voltage protection circuit should be connected to the test circuit to discharge the energy storage capacitors C1 and C2. After waiting for a period of time, the high voltage protection circuit and the low voltage protection circuit should be disconnected, and the drive circuit 170 should be controlled to make the power device under test (DUT) in the off state.

[0083] like Figure 4 As shown, the soft shear test consists of the following stages:

[0084] A. The first stage is that the high-voltage source V1 charges the energy storage capacitor C1 to reach the target set voltage value. The current limiting module 180 limits the current by 20mA. During the charging process of the high-voltage source C1 to the energy storage capacitor C1, the voltage between the drain and source of the power device under test (DUT) will increase as the voltage on capacitor C1 increases, thereby realizing the generation of 2DEG high voltage trapping. During this stage, the power device under test (DUT) is in the off state, the high voltage protection circuit is not connected to the circuit, and the resistor R1 is connected to the circuit. The resistance value is determined by the set output current IDS and voltage VDS. At this time, the control blocking module 110 is in the conducting state, and the control discharging module 200 is in the off state. This stage is the high voltage impulse stage.

[0085] B. In the second stage, the high-voltage blocking tube in the blocking module 110 cuts off the connection between the first voltage source module 120 and the power device under test (DUT), and at the same time opens the discharge module 200 to complete the discharge of the drain (D) voltage of the power device under test (DUT).

[0086] C. The third stage is to first shut down the discharge module 200 after the second stage has been executed for a period of time, and then simultaneously turn on the blocking module 110 and the power device under test (DUT). The energy storage capacitor C1 discharges the resistor R1 and the power device under test (DUT) to generate a large current to achieve low-voltage decapsulation of the power device under test (DUT). When the power device under test (DUT) achieves low-voltage decapsulation, the measurement branch will be connected to the test circuit, thereby realizing the measurement of the drain-source voltage VDS 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).

[0087] D. If it is a continuous test, repeat the first and second stages. During this process, the high voltage source V1 and the low voltage source V2 continuously charge the energy storage capacitors C1 and C2. If the test is stopped, the fourth stage will be executed.

[0088] E. The fourth stage involves controlling the high-voltage protection circuit and the low-voltage protection circuit to connect to the test circuit, discharging the energy storage capacitors C1 and C2, waiting for a period of time, and then controlling the high-voltage protection circuit and the low-voltage protection circuit to disconnect, and controlling the drive circuit 170 to make the power device under test (DUT) in the off state.

[0089] Figure 5 This is a timing diagram for hard-cut discontinuous testing. Time t0 to t1 represents the first stage, time t1 to t2 represents the second stage, and time t2 onwards represents the third stage. VG_Driver represents the gate drive of the power device under test (DUT), IDS is the current flowing through the DUT, and VDS is the drain-source voltage of the DUT. The time of the first stage T1 can be set to 0 to 10 seconds, and the time of the second stage T2 can be set to 1 to 100 seconds.

[0090] Figure 6 This is a timing diagram for a hard-cut continuous test. Time intervals t0 to t1 represent the first stage, t1 to t2 represent the second stage, t2 to t3 represent the first stage, t3 to t4 represent the second stage, and t4 onwards represent the third stage. VG_Driver represents the gate drive of the power device under test (DUT), IDS is the current flowing through the DUT, and VDS is the drain-source voltage of the DUT. The time of the first stage T1 can be set to 0–10 s, and the time of the second stage T2 can be set to 1–100 s. This timing diagram only shows the waveforms of two consecutive tests; waveforms from other tests are superimposed on this waveform.

[0091] Figure 7 This is a timing diagram for a soft-cut discontinuous test. The time intervals t0 to t1 (T1) represent the first stage, t1 to t2 (T2) represent the second stage, t2 to t3 (T3) represent the third stage, and the period after t3 is the fourth stage. VG_Driver represents the gate drive of the power device under test (DUT), IDS is the current flowing through the DUT, and VDS is the drain-source voltage of the DUT. The time of the first stage T1 can be set to 0–10 s, the time of the second stage T2 can be set to 0–10 ms, and the time of the third stage T3 can be set to 1 μs–100 μs.

[0092] Figure 8 This is a timing diagram for continuous soft-switching tests. Time intervals t0-t1 represent the first stage, t1-t2 the second stage, t2-t3 the third stage, t3-t4 the first stage, t4-t5 the second stage, t5-t6 the third stage, and t6 onwards the fourth stage. VG_Driver represents the gate drive of the power device under test (DUT), IDS is the current flowing through the DUT, and VDS is the drain-source voltage of the DUT. The time of the first stage T1 can be set to 0-10s, and the time of the second stage T2 can be set to 1us-100us. Only the waveforms of two consecutive tests are shown in the timing diagram; waveforms of other tests are superimposed on this waveform.

[0093] The magnitude and accuracy of the drain-source voltage of the power measurement device (DUT) are determined by sampling unit 1, sampling unit 2, and sampling unit 3. Specifically, the drain-source voltage VDS = 2V. 11 -V 12 -V 12 V 11 This represents the voltage value sampled by sampling unit 1, V. 12 This represents the voltage value sampled by sampling unit 2, V. 13This represents the voltage value sampled by sampling unit 3. The dynamic Ron(ds) of the power device under test (DUT) is calculated as follows: Ron(ds) = VDS / IDS, where IDS is the current value sampled by current sampling module 160.

[0094] The power device dynamic on-resistance testing apparatus provided in this application measures a branch current that accounts for less than 0.5% of the main circuit current. The consistency of the isolation diodes in the isolation module 130 can be avoided and optimized through a calibration scheme. Overall, the theoretically calculated voltage measurement accuracy is less than 1%. This testing apparatus is simple in structure and low in cost. Utilizing high-voltage isolation diodes, resistors, capacitors, and a low-voltage source significantly reduces the complexity of the test circuit, thereby lowering its cost. Because 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 scheme and improving its response speed, thus meeting the measurement requirements of dynamic Ron(ds) for GaN power devices.

[0095] Furthermore, by employing a blocking module 110 and a discharging module 200, and combining high-voltage blocking and discharging transistors, the soft and hard cut test logic for GaN power devices is implemented by controlling their on / off timing. The different states of the blocking module 110 and the discharging module 200 allow for arbitrary switching between soft and hard cut tests. The entire test structure is simple, easy to operate, and the extraction accuracy of dynamic Ron(ds) is also increased.

[0096] 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.

[0097] 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 discharge module is connected to the first terminal of the power device under test and is used to release the residual voltage of the power device under test after the first voltage source module completes the voltage surge. 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 data when the first voltage source module supplies current to the second terminal of the power device under test. The voltage and current 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 isolation module includes isolation diodes D1 and D2. The cathode of isolation diode D1 is connected to the first terminal of the DUT, and the anode of isolation diode D1 is connected to the cathode of isolation diode D2. The anode of isolation diode D2 is connected to the second voltage source module. The voltage data includes the cathode voltage of isolation diode D2, the anode voltage of isolation diode D2, and the voltage at the second terminal of the DUT. 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, 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.

3. The testing apparatus according to claim 1, characterized in that, The first current limiting module and / or the second current limiting module are programmable resistor matrices.

4. The testing apparatus according to claim 1, characterized in that, The first voltage source module includes a high voltage source and an energy storage capacitor C1. 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.

5. The testing apparatus according to claim 1, characterized in that, The second voltage source module includes a low voltage source and an energy storage capacitor C2. 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.

6. A method for testing the dynamic on-resistance of a power device, characterized in that, include: The control blocking module is turned on, the discharge module is turned off, and the drive circuit controls the power device under test to be in a turned-off state so that the first voltage source module can apply 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 discharge module is connected to the first 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 data is acquired by the voltage sampling module; the voltage data is acquired 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 current data collected by the current sampling module; the current data is acquired 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. The voltage and current 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 isolation module includes isolation diodes D1 and D2. The cathode of isolation diode D1 is connected to the first terminal of the DUT, and the anode of isolation diode D1 is connected to the cathode of isolation diode D2. The anode of isolation diode D2 is connected to the second voltage source module. The voltage data includes the cathode voltage of isolation diode D2, the anode voltage of isolation diode D2, and the voltage at the second terminal of the DUT.

7. The test method according to claim 6, characterized in that, The control blocking module is turned on, the discharge module is turned off, and the drive circuit controls the power device under test to be in a turned-off state, so that after the first voltage source module applies a voltage surge to the power device under test, the system further includes: The blocking module is turned off and the discharge module is turned on, so that the discharge module can release the residual voltage of the power device under test; After controlling the power device under test to conduct through the driving circuit, the method further includes: controlling the blocking module to conduct and turning off the discharge module.

8. The test method according to claim 6, characterized in that, After the control blocking module is turned on, the discharge module is turned off, and the power device under test is controlled to be in a turned-off state through the drive circuit, the method further includes: charging the energy storage capacitor C1 through a high voltage source; wherein, the first voltage source module includes a high voltage source and an energy storage capacitor C1, 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.

9. The test method according to any one of claims 6-8, characterized in that, After acquiring the current data obtained by the current sampling module, the method further includes: The control blocking module is turned on, the discharge module is turned off, and the power device under test is controlled to be in a turned-off state through the drive circuit, so that the first voltage source module performs voltage impact on the power device under test until the preset number of consecutive tests are completed.

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