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. An isolation module blocks the first terminal of the power device under test (DUT) from the voltage source module when it is off. The voltage source module applies a voltage surge to the DUT when the isolation module is on and the DUT is off. A discharge module releases the residual voltage in the DUT after the voltage source module completes the voltage surge. A voltage sampling module acquires voltage data when the DUT is on after the voltage surge and the DUT is on. The obtained voltage 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] An isolation module is connected to the first pole of the power device under test and is used to block the first pole of the power device under test from the voltage source module when it is turned off.

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

[0008] 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 voltage source module completes the voltage surge.

[0009] A voltage sampling module is connected to the first and second terminals of the power device under test. It is used to collect voltage data when the power device under test is in the conducting state after the voltage source module applies a voltage impulse.

[0010] The voltage data is 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.

[0011] In one embodiment, the voltage sampling module includes a voltage divider resistor R2, a voltage divider resistor R3, a switch, a first sampling circuit, and a second sampling circuit. The first end of the voltage divider resistor R2 is connected to the first terminal of the power device under test, the second end of the voltage divider resistor R2 is connected to the first end of the voltage divider resistor R3, the second end of the voltage divider resistor R3 is connected to the second terminal of the power device under test through the switch, the first sampling circuit is connected in parallel with the voltage divider resistor R3, and the second sampling circuit is connected in parallel with the switch.

[0012] In one embodiment, the testing apparatus further includes:

[0013] 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.

[0014] In one embodiment, the testing apparatus further includes:

[0015] A current limiting module is provided, and the isolation module is connected to the first pole of the power device under test through the current limiting module.

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

[0017] A current sampling module is connected to the second terminal of the power device under test (DUT) and is used to collect current data when the DUT is in the on state after the voltage source module applies a voltage surge. The current data is used to calculate the dynamic on-resistance of the DUT.

[0018] In one embodiment, the 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 isolation 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.

[0019] A method for testing the dynamic on-resistance of a power device, comprising:

[0020] The control isolation module is turned on, the discharge module is turned off, and the drive circuit controls the power device under test to be in the off state so that the 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, and the voltage source module is connected to the first terminal of the power device under test through the isolation module;

[0021] The driving circuit controls the power device under test to be in a conducting state, and acquires the voltage data obtained by the voltage sampling module; the voltage sampling module is connected to the first and second terminals of the power device under test.

[0022] The voltage data is 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.

[0023] In one embodiment, the control isolation 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 voltage source module applies a voltage surge to the power device under test, the method further includes:

[0024] The isolation 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;

[0025] After the power device under test is controlled to be in the conducting state by the driving circuit, and before the voltage data is acquired by the voltage sampling module, the method further includes: controlling the isolation module to be turned on and turning off the discharge module.

[0026] In one embodiment, after controlling the power device under test to be in a conducting state through the driving circuit and acquiring the voltage data obtained by the voltage sampling module, the method further includes:

[0027] Acquire current data collected by the current sampling module; the current sampling module is connected to the second electrode of the power device under test.

[0028] The dynamic on-resistance of the power device under test is calculated based on the voltage and current data.

[0029] In one embodiment, after the control isolation 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:

[0030] The high-voltage source is controlled to charge the energy storage capacitor C1; wherein the voltage source module includes the high-voltage source and the 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 isolation 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.

[0031] In one embodiment, before the control isolation module is turned on, the discharge module is turned off, and the power device under test is controlled to be in the off state by the drive circuit, the embodiment further includes: controlling the switch to be in the on state.

[0032] The voltage data obtained by the voltage sampling module includes: controlling the switch to be in the off state, and obtaining the voltage data obtained by the first sampling circuit and the second sampling circuit.

[0033] The voltage sampling module includes a voltage divider resistor R2, a voltage divider resistor R3, a switch, a first sampling circuit, and a second sampling circuit. The first end of the voltage divider resistor R2 is connected to the first terminal of the power device under test, the second end of the voltage divider resistor R2 is connected to the first end of the voltage divider resistor R3, and the second end of the voltage divider resistor R3 is connected to the second terminal of the power device under test through the switch. The first sampling circuit is connected in parallel with the voltage divider resistor R3, and the second sampling circuit is connected in parallel with the switch.

[0034] In one embodiment, after calculating the dynamic on-resistance of the power device under test based on the voltage data and the current data, the method further includes:

[0035] The high-voltage source is controlled to stop outputting voltage, the isolation module is turned off, and the discharge module is turned on;

[0036] The switch is controlled to be in the ON state, and the power device under test is controlled to be in the OFF state through the drive circuit.

[0037] In one embodiment, after the current sampling module acquires the current data, and before calculating the dynamic on-resistance of the power device under test based on the voltage data and the current data, the method further includes:

[0038] The control isolation module is turned on, the discharge 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 voltage source module performs voltage impact on the power device under test until the preset number of consecutive tests are completed.

[0039] The aforementioned test apparatus and method for the dynamic on-resistance of power devices involves an isolation module that blocks the first terminal of the power device under test (DUT) from the voltage source module when the isolation module is off. The voltage source module then applies a voltage surge to the DUT when the isolation module is on and the DUT is off. A discharge module releases the residual voltage in the DUT after the voltage source module completes the voltage surge. A voltage sampling module acquires voltage data after the voltage source module applies the voltage surge and the DUT is on. The obtained voltage 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

[0040] 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;

[0041] Figure 2 This is a flowchart illustrating a method for testing the dynamic on-resistance of a power device in one embodiment.

[0042] Figure 3 This is a timing diagram for a hard-cut discontinuity test of the dynamic on-resistance of a power device in one embodiment;

[0043] Figure 4 This is a timing diagram for a hard-cut continuous test of the dynamic on-resistance of a power device in one embodiment;

[0044] Figure 5 This is a timing diagram for a soft-cut discontinuity test of the dynamic on-resistance of a power device in one embodiment.

[0045] Figure 6 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

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Based on this, this application provides a testing device for the dynamic on-resistance of power devices. When the isolation module is off, it blocks the first terminal of the power device under test from the voltage source module. When the isolation module is on and the power device under test is off, the voltage source module applies a voltage surge to the power device under test. The discharge module releases the residual voltage in the power device under test after the voltage source module completes the voltage surge. The voltage sampling module acquires voltage data when the power device under test is on after the voltage surge from the voltage source module. The obtained voltage data can be further used to calculate the dynamic on-resistance of the power device under test. The device has a simple structure and low cost.

[0054] In one embodiment, such as Figure 1 As shown, a test device for the dynamic on-resistance of a power device is provided, including an isolation module 110, a voltage source module 120, a voltage sampling module 150, and a discharge module 200. The isolation module 110 is connected to the first terminal of the power device under test (DUT), the voltage source module 120 is connected to the isolation module 110, the discharge module 200 is connected to the first terminal of the DUT, and the voltage sampling module 150 is connected to the first and second terminals of the DUT. The isolation module 110 is used to block the first terminal of the DUT from the voltage source module 120 when it is off. The voltage source module 120 is used to apply a voltage impulse to the DUT when the isolation module 110 is on and the DUT is off. The discharge module 200 is used to release the residual voltage of the DUT after the voltage source module 120 completes the voltage impulse. The voltage sampling module 150 is used to collect voltage data when the DUT is on after the voltage source module 120 applies the voltage impulse and the DUT is on.

[0055] The voltage data is 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.

[0056] In one embodiment, the testing device further includes a current sampling module 160, which is connected to the second terminal of the power device under test (DUT). The current sampling module 160 is used to collect current data when the power device under test (DUT) is in the on state after the voltage source module 120 applies a voltage surge, and the current data is used to calculate the dynamic on-resistance of the power device under test (DUT).

[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 isolation 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 attached figures). The external controller controls the switching on and off of the isolation module 110, controls the drive circuit 170 to drive the DUT to switch on and off, controls the voltage sampling module 150 to sample voltage data, and receives the 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 voltage source module 120 to control the voltage source module 120 to apply voltage impulses to the DUT.

[0058] At the start of the test, the isolation 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 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 isolation module 110 is not unique; it can be a high-voltage relay, a MOS, an IGBT, or even a GaN device.

[0059] After the high-voltage impulse duration is set for the power device under test (DUT), the drive circuit 170 controls the DUT to conduct, allowing the voltage source module 120 to supply 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 synchronously perform voltage and current sampling. 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 current sampling module 160 quantizes the current through the DUT by sampling 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 of the non-inductive shunt is connected to the first voltage source module 120. The differential sampling circuit is connected to the first and second terminals of the non-inductive shunt. The differential sampling circuit can be connected to an external controller to receive the acquired current data.

[0060] Furthermore, after the voltage source module 120 applies a voltage surge to the power device under test (DUT), it also controls the isolation 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 isolation module 110 isolates 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 complete, the drive circuit 170 controls the DUT to turn on, then controls the isolation 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.

[0061] The aforementioned test apparatus for the dynamic on-resistance of power devices includes an isolation module 110 that blocks the first terminal of the power device under test (DUT) from the voltage source module 120 when it is off. When the isolation module 110 is on and the DUT is off, the voltage source module 120 applies a voltage surge to the DUT. The discharge module 200 releases the residual voltage on the DUT after the voltage source module 120 completes the voltage surge. The voltage sampling module 150 acquires voltage data when the DUT is on after the voltage surge from the voltage source module 120. The obtained voltage data can be further used to calculate the dynamic on-resistance of the power device under test. The apparatus is simple in structure and low in cost.

[0062] In one embodiment, the testing apparatus further includes a current limiting module 180, through which the isolation module 110 is connected to the first terminal of the power device under test (DUT). The current limiting module 180 includes a resistor R1, which can be a programmable resistor matrix or a single resistor. An external controller can be connected to the current limiting module 180 to adjust the resistance value of R1 as needed, thereby regulating the current supplied to the DUT. Specifically, the current limiting module 180 can provide an adjustable current of 0–10A, and can be extended to an adjustable current of 0–30A.

[0063] It is understood that the structures of the voltage source module 120 and the voltage sampling module 150 are not unique; in one embodiment, such as... Figure 1 As shown, the 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 isolation 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, after controlling the isolation module 110 to conduct and controlling the power device under test (DUT) to be in the off state through the drive circuit 170, the high-voltage source V1 is also controlled to charge the energy storage capacitor C1 for a preset time to provide a voltage surge to the DUT. The voltage source module 120 may also include a high-voltage protection circuit, which is connected in parallel with the energy storage capacitor C1 and discharges the energy storage capacitor C1 when it is conducting. An external controller can be connected to the high-voltage protection circuit to control its on / off state.

[0064] Furthermore, the voltage sampling module 150 includes voltage divider resistors R2 and R3, a switch 152, a first sampling circuit 154, and a second sampling circuit 156. The first terminal of voltage divider resistor R2 is connected to the first terminal of the power device under test (DUT), and the second terminal of voltage divider resistor R2 is connected to the first terminal of voltage divider resistor R3. The second terminal of voltage divider resistor R3 is connected to the second terminal of the DUT via switch 152. The first sampling circuit 154 is connected in parallel with voltage divider resistor R3, and the second sampling circuit 156 is connected in parallel with switch 152. Switch 152 can be a passively switched device such as a MOS, IGBT, or relay. The first sampling circuit 154 and the second sampling circuit 156 can each employ a sampling operational amplifier circuit. Voltage divider resistors R2 and R3 attenuate the voltage at point A to below the safe voltage of the sampling single-channel input stage operational amplifier. Similarly, an external controller can be connected to switch 152, first sampling circuit 154 and second sampling circuit 156 to control the on / off state of switch 152 and receive the relevant voltage data sampled by first sampling circuit 154 and second sampling circuit 156.

[0065] Specifically, after the control isolation module 110 is turned on and the drive circuit 170 controls the power device under test (DUT) to be in the off state, the switch 152 is also turned on, so that the voltage at point A changes with the voltage of the first terminal of the DUT. After the voltage source module 120 applies a voltage surge to the DUT for a period of time, the control drive circuit 170 turns the DUT on, and the switch 152 in the voltage sampling module 150 is turned off. At this time, the energy storage capacitor C1 discharges through the resistor R1 and the DUT to generate a large current, realizing low-voltage detrapping of the DUT. The first sampling circuit 154 and the second sampling circuit 156 measure the voltage data. By subtracting the two voltage data, the change in the drain-source voltage VDS of the DUT when it is turned on can be obtained. The current flowing through the DUT is measured by the current sampling module 160, and the dynamic on-resistance of the DUT can be calculated using Ohm's law.

[0066] After calculating the dynamic on-resistance of the power device under test based on the voltage and current data, the high-voltage source V1 is controlled to stop outputting voltage, the isolation module 110 is turned off, and the discharge module 200 is turned on; the control switch 152 is in the on state, and the power device under test DUT is controlled to be in the off state through the drive circuit 170.

[0067] Furthermore, after completing one voltage and current data test, the isolation module 110 can be turned on again, the discharge module 700 can be turned off, and the power device under test (DUT) can be controlled to be in the off state through the drive circuit 170. The voltage source module 120 then applies a voltage surge to the DUT again until a preset number of continuous 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 continuous tests, or by removing abnormal data from the voltage and current data and then averaging them separately. Combining voltage and current data from multiple tests to analyze the dynamic on-resistance provides higher accuracy.

[0068] In one embodiment, such as Figure 2 As shown, a method for testing the dynamic on-resistance of power devices is also provided, including:

[0069] Step S100: The isolation module is turned on, the discharge module is turned off, and the drive circuit controls the power device under test to be in the off state, so that the 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, and the voltage source module is connected to the first terminal of the power device under test through the isolation module.

[0070] Step S200: The drive circuit controls the power device under test (DUT) to be in the on state, and acquires the voltage data obtained by the voltage sampling module. The voltage sampling module is connected to the first and second terminals of the DUT; the voltage data is used to calculate the dynamic on-resistance of the DUT; the DUT includes a first, second, and third terminal, and the voltage difference between the third and second terminals determines the output characteristics between the first and second terminals of the DUT.

[0071] In one embodiment, after step S100, the method further includes: controlling the isolation module to turn off and the discharge module to turn on, so that the discharge module releases the residual voltage of the power device under test. After controlling the power device under test to be in the conducting state via the driving circuit in step S200, and before acquiring the voltage data obtained by the voltage sampling module, the method further includes: controlling the isolation module to turn on and turning off the discharge module.

[0072] In one embodiment, after step S200, the method further includes: acquiring current data collected by the current sampling module; calculating the dynamic on-resistance of the power device under test based on the voltage data and the current data; and connecting the current sampling module to the second terminal of the power device under test.

[0073] In one embodiment, after controlling the isolation module to be turned on, the discharge module to be turned off, and the power device under test to be turned off through the drive circuit in step S100, the method further includes: controlling the high voltage source to charge the energy storage capacitor C1; wherein, the voltage source module includes the high voltage source and the 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 isolation 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.

[0074] In one embodiment, before step S100 involves controlling the isolation module to be on, the discharge module to be off, and controlling the power device under test to be in the off state via the drive circuit, the method further includes: controlling the switch to be on; step S200 involves acquiring voltage data obtained by the voltage sampling module, including: controlling the switch to be off, and acquiring voltage data obtained by the first sampling circuit and the second sampling circuit. The voltage sampling module includes a voltage divider resistor R2, a voltage divider resistor R3, a switch, a first sampling circuit, and a second sampling circuit. The first end of the voltage divider resistor R2 is connected to the first terminal of the power device under test, the second end of the voltage divider resistor R2 is connected to the first end of the voltage divider resistor R3, the second end of the voltage divider resistor R3 is connected to the second terminal of the power device under test via the switch, the first sampling circuit is connected in parallel with the voltage divider resistor R3, and the second sampling circuit is connected in parallel with the switch.

[0075] In one embodiment, after calculating the dynamic on-resistance of the power device under test based on voltage and current data, the method further includes: controlling the high-voltage source to stop outputting voltage, turning off the isolation module, and turning on the discharge module; controlling the switch to be in the on state, and controlling the power device under test to be in the off state through the drive circuit.

[0076] In one embodiment, after acquiring the current data collected by the current sampling module and before calculating the dynamic on-resistance of the power device under test based on the voltage data and current data, the method further includes: turning on the return control isolation module, turning off the discharge module, and controlling the power device under test to be in a turned-off state through the drive circuit, so that the voltage source module performs voltage impact on the power device under test, until a preset number of consecutive tests are completed.

[0077] 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.

[0078] Specifically, such as Figure 1 As shown, the power device dynamic on-resistance testing device provided in this application includes an isolation module 110, a voltage source module 120, a voltage sampling module 150, a current sampling module 160, a drive circuit 170, a current limiting module 180, and a discharge module 200. When the high-voltage source V1 in the voltage source module 120 applies high voltage to the power device under test (DUT), the switch 152 in the voltage sampling module 150 is turned on by default to prevent damage to the first sampling circuit 154 and the second sampling circuit 156 caused by points A and D being at the same potential.

[0079] The dynamic on-resistance test of power devices is specifically divided into hard-cut test and soft-cut test, as follows:

[0080] (1) The hard-cut test is divided into the following stages:

[0081] A. In the first stage, switch 152 in the control voltage sampling module 150 is always in the on state, and control discharge module 200 is in the off state. According to the set voltage value VDS and current value IDS, the main control program closes the resistor matrix in the current limiting module 180 and connects the appropriate resistor R1 into the test circuit.

[0082] B. In the second stage, 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 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 the energy storage capacitor C1 increases, thereby realizing the generation of 2DEG high voltage trapping. In this stage, the power device under test (DUT) is in the off state, and the high voltage protection circuit is not connected to the circuit. At this time, the voltage sampling module 150 reduces the voltage of the drain (D) of the power device under test (DUT) to below the safe voltage of the subsequent sampling circuit due to the resistor voltage division, but this voltage is not sampled at this time.

[0083] C. In the third 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 power device under test (DUT). The switch 152 in the voltage sampling module 150 will be turned off, so that the voltage at point A changes with the drain (D) voltage of 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. After sampling and processing by the first sampling circuit 154 and the second sampling circuit 156, the change of the drain-source voltage VDS of the power device under test (DUT) when it is turned on can be obtained. The current flowing through the power device under test (DUT) is measured by the current sampling module 160. Then, the dynamic Ron(ds) of the power device under test (DUT) can be calculated by Ohm's law.

[0084] D. In the fourth stage, the output of the high voltage source V1 should be controlled to 0V first, then the isolation module 110 should be controlled to be in the off state and the discharge module 200 should be controlled to be in the on state. The switch 152 in the voltage sampling module 150 should be in the on state. After waiting for a period of time, the drive circuit 170 should be controlled to make the power device under test (DUT) in the off state.

[0085] (2) The soft shear test is divided into the following stages:

[0086] A. The first stage is to control the switch 152 in the voltage sampling module 150 to be in the open state by default, so that the test branch composed of the voltage sampling module 150 is connected to the test main circuit. At the same time, the high voltage blocking tube in the isolation module 110 is controlled to be in the open state, and the high voltage discharge branch in the discharge module 200 is controlled to be in the closed state. The appropriate resistor R1 is selected according to the set voltage value VDS and current value IDS.

[0087] B. In the second stage, 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 V1 on 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 the energy storage capacitor C1 increases, thereby realizing the generation of 2DEG high voltage trapping. In this stage, the power device under test (DUT) is in the off state, and the high voltage protection circuit is not connected to the circuit, thus completing the high voltage impact on the device under test. At this time, a current of 1mA will pass through the measurement branch (resistors R2, R3 and switch 152).

[0088] C. In the third stage, after the high voltage impacts the power device under test (DUT) for a period of time in the soft-cut test logic, it is necessary to control the high voltage of the drain of the DUT to be released in advance, and then perform high current low voltage decapture. Therefore, it is necessary to control the high voltage blocking tube in the isolation module 110 to be in the blocking state, and at the same time control the high voltage discharge branch in the discharge module 200 to be in the conducting state. After releasing the high voltage signal on the drain of the DUT for a period of time, the fourth stage is entered.

[0089] D. In the fourth stage, the high-voltage blocking tube in the control isolation module 110 is in the open state, the high-voltage discharge branch in the control discharge module 200 is in the closed state, and the switch 152 in the control voltage sampling module 150 is in the blocked state, while the power device under test (DUT) is in the open state. At this time, the energy storage capacitor C1 discharges through the resistor R1 and the power device under test (DUT), and a large current flows through the power device under test (DUT), which obtains low-voltage decapsulation. In this stage, the voltages at points A and B in the voltage sampling module 150 are at the same potential as the voltage at point D. The first sampling circuit 154 and the second sampling circuit 156 respectively measure V AB With V BS By subtracting the values, the drain-source voltage VDS of the power device under test (DUT) can be obtained. The output current IDS is measured using the current sampling module 160. Finally, the result is obtained using R = (V AB -V BS ) / IDS obtains dynamic Ron results.

[0090] E. In the fifth stage, the output of the high voltage source V1 should be controlled to 0. At the same time, the discharge module 200 should be turned on for a period of time to discharge the energy storage capacitor C1. The drive circuit 170 should be controlled to turn off the power device under test (DUT). The switch 152 in the voltage sampling module 150 should be turned on.

[0091] Figure 3This is a timing diagram for a hard-cut discontinuous test. Time t0 to t1 represents the first stage, time t1 to t2 represents the second stage, time t2 to t3 represents the third stage, and time t3 onwards represents 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 to 10 seconds, and the time of the second stage T2 is 10 microseconds to 10 milliseconds.

[0092] Figure 4 This is a timing diagram for a hard-cut continuous test. Time intervals t0-t1 represent the first stage, t1-t2 the second stage, t2-t3 the third stage, and t3-t4 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 is 10us-10ms. Only the waveforms of two consecutive tests are shown in the timing diagram; waveforms of other tests are superimposed on this waveform.

[0093] Figure 5 This is the timing diagram for the soft-cut discontinuous test. 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, and t4 onwards represents the fifth stage. VG_Driver represents the gate drive of the power device under test (DUT), IDS is the current flowing through the shunt in the current sampling module 160, 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, the time of the second stage T2 can be set to 0 to 10 milliseconds, and the time of the third stage T3 can be set to 10 microseconds to 10 milliseconds.

[0094] Figure 6 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 fourth stage, and t4 onwards the fifth stage. VG_Driver represents the gate drive of the power device under test (DUT), IDS is the current flowing through the shunt in the current sampling module 160, and VDS is the drain-source voltage of the DUT. The time for the first stage T1 can be set to 0-10s, the time for the second stage T2 to 0-10ms, and the time for the third stage T3 to 10us-10ms. Only the waveforms from two consecutive tests are shown in the timing diagram; waveforms from other tests are superimposed on this waveform.

[0095] The magnitude and accuracy of the drain-source voltage of the power measurement device (DUT) are determined by the first sampling circuit 154 and the second sampling circuit 156. Specifically, the drain-source voltage VDS = V AB -V BS V AB This represents the voltage value sampled by the first sampling circuit 154, and similarly, V BS This represents the voltage value sampled by the second sampling circuit 156. The dynamic Ron(ds) of the power device under test (DUT) is calculated using the formula: Ron(ds) = VDS / IDS, where IDS is the current value sampled by the current sampling module 160.

[0096] The power device dynamic on-resistance testing device provided in this application uses a resistive load as the input source of IDS, featuring high flexibility, small size, simple operation, and the ability to achieve a wide range of current output. It achieves high-voltage attenuation and low-voltage testing by adding controllable switches at the source and low-side of the power device under test (DUT) to implement timing control. The device has a simple structure and high flexibility; its consistency is mainly affected by the switches, so devices with small junction capacitance and low on-resistance can be used. This testing device has a simple structure and low cost, greatly reducing the complexity of the test circuit and thus lowering its cost to some extent. During the high-voltage impulse phase, when the DUT is turned on, the voltage VDS changes with the voltage at point D, maintaining consistency and ensuring test accuracy.

[0097] Furthermore, by employing an isolation module 110 and a discharge module 200, and combining a high-voltage blocking tube and a high-voltage discharge tube, the soft and hard cut test logic for GaN power devices is implemented by controlling their on / off timing. The different states of the isolation module 110 and the discharge 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.

[0098] 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.

[0099] 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: An isolation module is connected to the first pole of the power device under test and is used to block the first pole of the power device under test from the voltage source module when it is turned off. The voltage source module is connected to the isolation module and is used to apply a voltage surge to the power device under test when the isolation module is turned on and the power device under test is turned off. 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 voltage source module completes the voltage surge. A voltage sampling module is connected to the first and second terminals of the power device under test. It is used to collect voltage data when the power device under test is in the conducting state after the voltage source module applies a voltage impulse. The voltage data is 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 voltage sampling module includes a voltage divider resistor R2, a voltage divider resistor R3, a switch, a first sampling circuit, and a second sampling circuit. The first terminal of the voltage divider resistor R2 is connected to the first terminal of the DUT, the second terminal of the voltage divider resistor R2 is connected to the first terminal of the voltage divider resistor R3, and the second terminal of the voltage divider resistor R3 is connected to the second terminal of the DUT through the switch. The first sampling circuit is connected in parallel with the voltage divider resistor R3, and the second sampling circuit is connected in parallel with the switch.

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, Also includes: A current limiting module is provided, and the isolation module is connected to the first pole of the power device under test through the current limiting module.

4. The testing apparatus according to claim 1, characterized in that, Also includes: 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 power device under test is in the conducting state after the voltage source module applies a voltage impulse; The current data is used to calculate the dynamic on-resistance of the power device under test.

5. The testing apparatus according to claim 4, characterized in that, The 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 isolation 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.

6. A method for testing the dynamic on-resistance of a power device, characterized in that, include: The control isolation module is turned on, the discharge module is turned off, and the drive circuit controls the power device under test to be in the off state so that the 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, and the voltage source module is connected to the first terminal of the power device under test through the isolation module; The driving circuit controls the power device under test to be in a conducting state, and acquires the voltage data obtained by the voltage sampling module; the voltage sampling module is connected to the first and second terminals of the power device under test. The voltage data is 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 voltage sampling module includes a voltage divider resistor R2, a voltage divider resistor R3, a switch, a first sampling circuit, and a second sampling circuit. The first terminal of the voltage divider resistor R2 is connected to the first terminal of the DUT, the second terminal of the voltage divider resistor R2 is connected to the first terminal of the voltage divider resistor R3, and the second terminal of the voltage divider resistor R3 is connected to the second terminal of the DUT through the switch. The first sampling circuit is connected in parallel with the voltage divider resistor R3, and the second sampling circuit is connected in parallel with the switch.

7. The test method according to claim 6, characterized in that, The control isolation 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 voltage source module applies a voltage surge to the power device under test, the system further includes: The isolation 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 the power device under test is controlled to be in the conducting state by the driving circuit, and before the voltage data is acquired by the voltage sampling module, the method further includes: controlling the isolation module to be turned on and turning off the discharge module.

8. The test method according to claim 6 or 7, characterized in that, After controlling the power device under test to be in a conducting state through the driving circuit and acquiring the voltage data obtained by the voltage sampling module, the method further includes: Acquire current data collected by the current sampling module; the current sampling module is connected to the second electrode of the power device under test. The dynamic on-resistance of the power device under test is calculated based on the voltage and current data.

9. The test method according to claim 8, characterized in that, After the control isolation module is turned on, the discharge module is turned off, and the power device under test is controlled to be in the off state through the drive circuit, the following steps are also included: The high-voltage source is controlled to charge the energy storage capacitor C1; wherein the voltage source module includes the high-voltage source and the 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 isolation 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.

10. The test method according to claim 8, characterized in that, Before the control isolation module is turned on, the discharge module is turned off, and the power device under test is controlled to be in the off state by the drive circuit, the control switch is also in the on state. The process of acquiring voltage data obtained by the voltage sampling module includes: controlling the switch to be in the off state, and acquiring voltage data obtained by the first sampling circuit and the second sampling circuit.

11. The test method according to claim 10, characterized in that, After calculating the dynamic on-resistance of the power device under test based on the voltage data and the current data, the method further includes: The high-voltage source is controlled to stop outputting voltage, the isolation module is turned off, and the discharge module is turned on; The switch is controlled to be in the ON state, and the power device under test is controlled to be in the OFF state through the drive circuit.

12. The test method according to claim 8, characterized in that, After the current data acquired by the current sampling module is obtained, and before the dynamic on-resistance of the power device under test is calculated based on the voltage data and the current data, the method further includes: The control isolation module is turned on, the discharge 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 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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