Testing device of power device

Abstract

The utility model discloses a testing device for a power device. The testing device comprises a first switch module, a second switch module and a clamping module, the first switch module is used for controlling the voltage applying duration of the direct-current voltage so as to determine the change of the dynamic threshold voltage and the dynamic on-resistance of the tested device under different voltage applying durations; the second switch module is connected with the control end of the tested device, the second switch module is used for controlling the tested device to be switched on or switched off, and when the drain-source current of the tested device is equal to the set current, the gate-source voltage of the tested device is the dynamic threshold voltage; the first end of the clamping module is connected with the first end of the tested device, the second end of the clamping module is connected with the second end of the tested device, and the clamping module is used for clamping and outputting drain-source voltage of the tested device. According to the utility model, the dynamic threshold voltage and the dynamic on-resistance of the tested device can be tested in the same period of the PWM control signal, so that the test time can be reduced, and the test cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power device testing, in particular to a power device testing device. Background Art

[0002] With the development and progress of science and technology, and the emergence of 5G commercialization, the third-generation semiconductor power devices have begun to enter the market, and the measurement of third-generation semiconductor power devices has become increasingly important.

[0003] The dynamic parameter test devices of the third-generation semiconductor power devices currently on the market, such as GaN (gallium nitride) and SiC (silicon carbide) devices, cannot test both the dynamic threshold voltage and dynamic on-resistance of the devices under test within the same cycle of the PWM control signal, resulting in long test time and high test cost. Utility Model Content

[0004] The utility model provides a testing device for a power device, which can test both the dynamic threshold voltage and the dynamic on-resistance of a device under test within the same cycle of a PWM control signal, thereby reducing the testing time and the testing cost.

[0005] The utility model provides a testing device for a power device, comprising: a first switch module, a second switch module and a clamp module; the first switch module is connected to the first end of the device under test, and the first switch module is used to control the pressure duration of the DC voltage to determine the changes in the dynamic threshold voltage and dynamic on-resistance of the device under test under different pressure durations; the second switch module is connected to the first end, the second end and the control end of the device under test, and the second switch module is used to control the device under test to be turned on or off, and when the drain-source current of the device under test is equal to the set current, the gate-source voltage of the device under test is the dynamic threshold voltage; the first end of the clamp module is connected to the first end of the device under test, the second end of the clamp module is connected to the second end of the device under test, and the clamp module is used to clamp the drain-source voltage of the device under test and output it.

[0006] Optionally, the first switch module includes a first drive unit and a first transistor; the control end of the first drive unit is connected to a first PWM control signal, the first end of the first drive unit is connected to the gate of the first transistor, the second end of the first drive unit is connected to the second pole of the first transistor, and the first drive unit is used to control the first transistor to be turned on or off according to the first PWM control signal; the first pole of the first transistor is connected to the first power supply end, and the second pole of the first transistor is connected to the first end of the device under test; and / or, the second switch module includes a second drive unit, a first resistor unit, a first diode, a second diode and a second transistor; the control end of the second drive unit is connected to a second PWM control signal, the first end of the second drive unit is connected to the gate of the second transistor, the second end of the second drive unit is connected to the second pole of the second transistor, and the second drive unit is used to control the second transistor to be turned on or off according to the second PWM control signal; the first end of the first resistor unit is connected to the second power supply end, and the second end of the first resistor unit is respectively connected to the anode of the first diode and the anode of the second diode; the cathode of the first diode is connected to the first end of the device under test, and the cathode of the second diode is connected to the first pole of the second transistor.

[0007] Optionally, the second switch module also includes a third drive unit; the control end of the third drive unit is connected to a third PWM control signal, the first end of the third drive unit is connected to the second electrode of the second transistor, the second end of the third drive unit is connected to the second end of the device under test, and the third drive unit is used to control the device under test to be turned on or off according to the third PWM control signal; the power supply end of the third drive unit is connected to a gate drive voltage, and the gate drive voltage is adjustable.

[0008] Optionally, the clamping module includes a third switch module, an oscillation suppression module and a filtering module, the control end of the third switch module is connected to a fourth PWM control signal, the first end of the third switch module is connected to the first end of the device under test, the second end of the third switch module is connected to the first end of the oscillation suppression module, the third switch module is used to block the drain-source voltage of the device under test in an off state; the second end of the oscillation suppression module is connected to the second end of the device under test, and is used to limit the drain-source voltage oscillation caused by switching noise; the filtering module is connected in parallel with the oscillation suppression module, and is used to filter out the noise generated by the third switch module during the switching process.

[0009] Optionally, the third switch module includes a fourth drive unit and a third transistor; the control end of the fourth drive unit serves as the control end of the third switch module, the first electrode of the third transistor serves as the first end of the third switch module, and the second electrode of the third transistor serves as the second end of the third switch module; the first end of the fourth drive unit is connected to the gate of the third transistor, the second end of the fourth drive unit is connected to the second electrode of the third transistor, and the fourth drive unit is used to control the third transistor to be turned on or off according to a fourth PWM control signal.

[0010] Optionally, the oscillation suppression module includes a third diode and a fourth diode; the anode of the third diode is connected to the cathode of the fourth diode and serves as the first end of the oscillation suppression module, and the cathode of the third diode is connected to the anode of the fourth diode and serves as the second end of the oscillation suppression module; and / or, the filtering module includes a first capacitor and a first resistor, and the oscillation suppression module is connected in parallel with the first capacitor and the first resistor, respectively.

[0011] Optionally, the power device testing device also includes a first power supply module and a second power supply module; the first power supply module is connected to the first switch module, and the first power supply module is used to provide different DC voltages for the device under test; the second power supply module is respectively connected to the second switch module and the device under test, and the second power supply module provides constant current for the device under test.

[0012] Optionally, the testing device for the power device also includes a resistive load, an inductive load, a first relay and a second relay; the resistive load and the first relay are connected in series between the first end of the first switch module and the first power supply end of the first power supply module; the inductive load is connected in series with the second relay and in parallel at both ends of the resistive load and the first relay.

[0013] Optionally, the power device test device further includes a current sampling module, a first end of the current sampling module is connected to a second end of the device under test, and a second end of the current sampling module is grounded, for collecting drain-source current of the device under test.

[0014] Optionally, the power device testing device also includes a main control module, which is used to output a PWM control signal to control the device under test to be in different working modes, wherein the working modes include hard on and hard off mode, hard on and soft off mode, soft on and soft off mode, and soft on and hard off mode.

[0015] The test device of the power device provided by the utility model includes a first switch module, a second switch module and a clamp module. The first switch module can control the pressure duration of the DC voltage to determine the changes in the threshold voltage and on-resistance of the device under test under different pressure durations. The drain-source voltage of the device under test during the forward conduction period is collected by the clamp module, and the dynamic on-resistance of the device under test can be obtained by dividing the drain-source voltage by the drain-source current. And within the same cycle of the PWM control signal, the gate-source voltage of the device under test can be tested. When the drain-source current of the device under test is equal to the set current, the gate-source voltage of the device under test DUT is the dynamic threshold voltage. In summary, the test device provided by the utility model can test both the dynamic on-resistance of the device under test and the dynamic threshold voltage of the device under test within the same cycle of the PWM control signal, saving test time and reducing test costs.

[0016] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present utility model, nor are they intended to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a structural schematic diagram of a power device testing device provided by an embodiment of the utility model;

[0019] Figure 2 It is a structural schematic diagram of another power device testing device provided by an embodiment of the utility model;

[0020] Figure 3 It is a structural schematic diagram of a third driving unit provided in an embodiment of the utility model;

[0021] Figure 4 It is a structural schematic diagram of another power device testing device provided by an embodiment of the utility model;

[0022] Figure 5 It is a structural schematic diagram of another power device testing device provided by an embodiment of the utility model;

[0023] Figure 6 It is a structural schematic diagram of another power device testing device provided by an embodiment of the utility model;

[0024] Figure 7 It is a structural schematic diagram of another power device testing device provided by an embodiment of the utility model;

[0025] Figure 8 It is a waveform diagram of a device under test in a hard-on and hard-off mode provided by an embodiment of the utility model;

[0026] Fig. 9 It is a waveform diagram of a device under test in a hard-on and soft-off mode provided by an embodiment of the utility model;

[0027] Fig.10 It is a waveform diagram of a device under test in a soft-on and hard-off mode provided by an embodiment of the utility model;

[0028] Fig.11It is a waveform diagram of a device under test in a soft-on and soft-off mode provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0031] Figure 1 is a schematic diagram of the structure of a power device testing device provided by an embodiment of the utility model, such as Figure 1 As shown, the testing device includes: a first switch module 11 , a second switch module 12 and a clamping module 13 .

[0032] The first switch module 11 is connected to the first terminal D of the device under test DUT, and the first switch module 11 is used to control the duration of the DC voltage application to determine the changes in the dynamic threshold voltage and dynamic on-resistance of the device under test DUT under different durations of pressure application. The second switch module 12 is connected to the first terminal D, the second terminal S and the control terminal G of the device under test DUT, and the second switch module 12 is used to control the device under test DUT to be turned on or off. When the drain-source current of the device under test DUT is equal to the set current, the gate-source voltage Vgs of the device under test DUT is the dynamic threshold voltage. The first end of the clamp module 13 is connected to the first terminal D of the device under test DUT, and the second end of the clamp module 13 is connected to the second terminal S of the device under test DUT. The clamp module 13 is used to clamp the drain-source voltage Vds of the device under test DUT and output it.

[0033] Specifically, the first switch module 11 and the second switch module 12 refer to switches that can realize on-off control through electrical signals or realize on-off control according to the characteristics of the components themselves. The first switch module 11 and the second switch module 12 can be either unidirectional switches, such as a unidirectionally conductive switch composed of a bidirectional switch and a diode in series, or bidirectional switches, such as a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, MOSFET) or an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) with an anti-parallel freewheeling diode. It can be understood that the specific types of the first switch module 11 and the second switch module 12 can be selected and set according to the actual application scenario, etc., and the utility model is not limited here.

[0034] The device under test may be a GaN power tube, which may be an N-type channel GaN power tube or a P-type channel GaN power tube. The control end of the device under test is the gate of the GaN power tube, the first end is the drain of the GaN power tube, and the second end is the source of the GaN power tube.

[0035] It can be understood that the clamping module 13 can be various devices or module circuits with a voltage sampling function.

[0036] Continue to refer Figure 1 The power device test device further includes a first power module 14 and a second power module 15. The first power module 14 is connected to the first switch module 11, and the first power module 14 is used to provide different DC voltages for the device under test DUT. The second power module 15 is respectively connected to the second switch module 12 and the device under test DUT, and the second power module 15 provides a constant current for the device under test DUT.

[0037] by Figure 1 Taking the structure of the test device shown in FIG. 1 as an example, the test device provided in this embodiment measures the dynamic on-resistance and dynamic threshold voltage of the device under test through the following process:

[0038] A plurality of cycles of PWM control signals are input to the first switch module 11 and the second switch module 12. The PWM control signals include a first PWM control signal and a second PWM control signal. The first PWM control signal controls the first switch module 11 to be turned on or off. The second PWM control signal controls the second switch module 12 to be turned on or off. By controlling the duration of the effective level in the first PWM control signal, the on-time of the first switch module 11 can be controlled. By controlling the on-time of the first switch module 11, the duration of the pressure applied to the first end of the device under test DUT by the DC voltage can be controlled. By controlling the duration of the pressure applied by the DC voltage, the changes in the dynamic threshold voltage and the dynamic on-resistance of the device under test DUT under different pressure durations can be determined. The effective level can be a high level or a low level. Exemplarily, if the transistor included in each switch module is an N-type transistor, the effective level may be a high level, the invalid level may be a low level, and each switch module is turned on at a high level and turned off at a low level; if the transistor included in each switch module is a P-type transistor, the effective level may be a low level, the invalid level may be a high level, and each switch module is turned off at a high level and turned on at a low level. This embodiment and the following embodiments are all described by taking the effective level as a high level and the invalid level as a low level as an example.

[0039] When the first switch module 11 is turned on, a DC voltage is applied to the first end of the device under test DUT. When the second switch module 12 is turned on, the device under test DUT can be controlled to turn on, and the drain-source voltage of the device under test DUT during the forward conduction period is collected through the clamp module 13, and the drain-source current of the device under test DUT during the forward conduction period is collected through the current sampling module. The dynamic on-resistance of the device under test DUT can be obtained by dividing the drain-source voltage Vds by the drain-source current Ids.

[0040] In the same cycle of the PWM control signal, the gate-source voltage of the device under test DUT can be tested. When the drain-source current Ids of the device under test DUT is equal to the set current, the gate-source voltage Vgs of the device under test DUT is the dynamic threshold voltage. The magnitude of the set current can be set according to actual needs. For example, the set current is equal to 10mA.

[0041] The test device of the power device provided by the utility model includes a first switch module, a second switch module and a clamp module. The first switch module can control the pressure duration of the DC voltage to determine the changes in the threshold voltage and on-resistance of the device under test under different pressure durations. The drain-source voltage of the device under test during the forward conduction period is collected by the clamp module, and the dynamic on-resistance of the device under test can be obtained by dividing the drain-source voltage by the drain-source current. And within the same cycle of the PWM control signal, the gate-source voltage of the device under test can be tested. When the drain-source current of the device under test is equal to the set current, the gate-source voltage of the device under test DUT is the dynamic threshold voltage. In summary, the test device provided by the utility model can test both the dynamic on-resistance of the device under test and the dynamic threshold voltage of the device under test within the same cycle of the PWM control signal, saving test time and reducing test costs.

[0042] The first switch module 11 and the second switch module 12 can be implemented in a variety of ways, and the present invention does not limit the implementation of the switch module. As an optional implementation provided in this embodiment, Figure 2 FIG. 1 is a schematic diagram of the structure of another power device testing device provided by an embodiment of the utility model. Figure 2 As shown, the first switch module 11 includes a first driving unit 110 and a first transistor Q1.

[0043] The control end of the first driving unit 110 is connected to the first PWM control signal PWM_G1, the first end of the first driving unit 110 is connected to the gate of the first transistor Q1, the second end of the first driving unit 110 is connected to the second electrode of the first transistor Q1, and the first driving unit 110 is used to control the first transistor Q1 to be turned on or off according to the first PWM control signal PWM_G1. The first electrode of the first transistor Q1 is connected to the first power supply terminal VCC1, and the second electrode of the first transistor Q1 is connected to the first terminal D of the device under test DUT.

[0044] And / or, the second switch module 12 includes a second driving unit 120, a first resistance unit 121, a first diode D1, a second diode D2 and a second transistor Q2.

[0045] The control end of the second driving unit 120 is connected to the second PWM control signal PWM_G2, the first end of the second driving unit 120 is connected to the gate of the second transistor Q2, the second end of the second driving unit 120 is connected to the second electrode of the second transistor Q2, and the second driving unit 120 is used to control the conduction or shutdown of the second transistor Q2 according to the second PWM control signal PWM_G1. The first end of the first resistor unit 121 is connected to the second power supply terminal VCC2, and the second end of the first resistor unit 121 is respectively connected to the anode of the first diode D1 and the anode of the second diode D2. The cathode of the first diode D1 is connected to the first end D of the device under test DUT, and the cathode of the second diode D2 is connected to the first electrode of the second transistor Q2.

[0046] Based on the above embodiments, optionally, continue to refer to Figure 2 , the second switch module 12 also includes a third driving unit 122; the control end of the third driving unit 122 is connected to the third PWM control signal PWM_G3, the first end G1 of the third driving unit 122 is connected to the second electrode of the second transistor Q2, the second end of the third driving unit 122 is connected to the second end S of the device under test DUT, and the third driving unit 122 is used to control the device under test DUT to turn on or off according to the third PWM control signal PWM_G3; the power supply end of the third driving unit 122 is connected to the gate drive voltage VCC_G4, and the gate drive voltage VCC_G4 is adjustable. Specifically, by controlling the gate drive voltage VCC_G4, different gate-source voltages Vgs can be applied to the gate of the device under test DUT, thereby determining the dynamic on-resistance and dynamic threshold voltage of the device under test DUT under different gate-source voltages Vgs.

[0047] In some embodiments, a first PWM control signal PWM_G1, a second PWM control signal PWM_G2, and a third PWM control signal PWM_G3 can be obtained through programming to provide switching instructions of different frequencies, double pulses, or continuous pulses for the first drive unit 110, the second drive unit 120, and the third drive unit 122, thereby realizing the turning on and off of the first transistor Q1, the second transistor Q2, and the device under test DUT.

[0048] Figure 3 is a schematic diagram of the structure of a third driving unit provided by an embodiment of the utility model, such as Figure 3 As shown, the third driving unit includes a driving chip U1 and a peripheral circuit. Optionally, the structures of the first driving unit 110, the second driving unit 120 and the third driving unit 122 may be the same.

[0049] Figure 4 FIG. 1 is a schematic diagram of the structure of another power device testing device provided by an embodiment of the utility model. Figure 4As shown, optionally, the clamping module 13 includes a third switch module 130 , an oscillation suppression module 131 and a filtering module 132 .

[0050] The control end of the third switch module 130 is connected to the fourth PWM control signal PWM_G4, the first end of the third switch module 130 is connected to the first end D of the device under test DUT, the second end of the third switch module 130 is connected to the first end of the oscillation suppression module 131, and the third switch module 130 is used to block the drain-source voltage of the device under test DUT in the off state; the second end of the oscillation suppression module 131 is connected to the second end S of the device under test DUT, and is used to limit the drain-source voltage oscillation caused by switching noise; the filter module 132 is connected in parallel with the oscillation suppression module 131, and is used to filter out the noise generated by the third switch module 130 during the switching process.

[0051] The present utility model embodiment does not specifically limit the specific implementation of the third switch module 130, the oscillation suppression module 131 and the filter module 132, as long as the corresponding functions can be achieved. As an optional implementation provided by this embodiment, Figure 5 FIG. 1 is a schematic diagram of the structure of another power device testing device provided by an embodiment of the utility model. Figure 5 As shown, the third switch module 130 includes a fourth driving unit 1301 and a third transistor Q3.

[0052] The control end of the fourth driving unit 1301 serves as the control end of the third switch module 130, the first electrode of the third transistor Q3 serves as the first end of the third switch module 130, and the second electrode of the third transistor Q3 serves as the second end of the third switch module 130; the first end of the fourth driving unit 1301 is connected to the gate of the third transistor Q3, the second end of the fourth driving unit 1301 is connected to the second electrode of the third transistor Q3, and the fourth driving unit 1301 is used to control the third transistor Q3 to be turned on or off according to the fourth PWM control signal PWM_G4. The structure of the fourth driving unit 1301 can be the same as that of the third driving unit 122.

[0053] Based on the above embodiments, optionally, continue to refer to Figure 5 The oscillation suppression module 131 includes a third diode D3 and a fourth diode D4. The anode of the third diode D3 is connected to the cathode of the fourth diode D4 and serves as the first end of the oscillation suppression module 131, and the cathode of the third diode D3 is connected to the anode of the fourth diode D4 and serves as the second end of the oscillation suppression module 131. When the device under test DUT and the third transistor Q3 are turned on, the positive electrode voltage across the fourth diode D4 during the conduction process is measured, and the dynamic conduction voltage of the device under test DUT is determined based on the positive electrode voltage and the conduction voltage drop of the fourth diode D4.

[0054] And / or, the filtering module 132 includes a first capacitor C1 and a first resistor R1, and the oscillation suppression module 131 is connected in parallel with the first capacitor C1 and the first resistor R1, respectively. By selecting the parameter values ​​of the first resistor R1 and the first capacitor C1, the passband cutoff frequency of the filtering module 132 can be set to limit the impact of high-frequency noise on the measurement.

[0055] Figure 6 FIG. 1 is a schematic diagram of the structure of another power device testing device provided by an embodiment of the utility model. Figure 6 As shown, the test device for the power device further includes a first power module 14 and a second power module 15. The first power module 14 is connected to the first switch module 11, and the first power module 14 is used to provide different DC voltages for the device under test DUT. The second power module 15 is respectively connected to the second switch module 12 and the device under test DUT, and the second power module 15 provides a constant current for the device under test DUT.

[0056] In some embodiments, the first power module 14 includes an adjustable voltage source V1. The adjustable voltage source V1 provides different DC voltages for the device under test DUT, and the voltage value provided by it is determined according to the demand, and the voltage value provided by it can be any reasonable value. Optionally, the voltage value provided by the adjustable voltage source is greater than 0V and less than or equal to 1200V. For example, the voltage value provided is 50V, 100V, 300V, 600V or 1200V, etc. In this embodiment, by setting the first power module 14 to provide different DC voltages for the device under test DUT, different DC voltages, that is, the influence of different drain-source voltages on the dynamic threshold voltage of the device under test DUT can be tested. In addition, by setting the first power module 14 to provide different DC voltages for the device under test DUT, different DC voltages, that is, the dynamic saturation current of the device under test DUT under the same pulse width of different drain-source voltages can be tested.

[0057] In some embodiments, the second power supply module 15 includes a constant voltage source V2. The constant voltage source V2 provides a constant voltage for the circuit, and the voltage value provided by the constant voltage source V2 is determined according to actual needs, and the voltage value provided by the constant voltage source V2 can be any reasonable value. Optionally, the voltage provided by the constant voltage source is greater than 0V and less than or equal to 10V, for example, the voltage provided can be 1V, 2V, 4V, 8V or 10V, etc.

[0058] like Figure 6 As shown, the first power supply module 14 further includes a second capacitor C2 and a third capacitor C3. The second capacitor C2 and the third capacitor C3 are filter capacitors for filtering out ripples of the adjustable voltage source V1.

[0059] The second power supply module 15 also includes a fourth capacitor C4, a fifth capacitor C5 and a common-mode inductor T1, the input end of the common-mode inductor T1 is connected to the fourth capacitor C4, the output end of the common-mode inductor T1 is connected to the fifth capacitor C5, the fourth capacitor C4 is connected in parallel with the constant voltage source V2, the first end of the fifth capacitor C5 is connected to the second switch module 12, and the second end of the fifth capacitor C5 is connected to the second end S of the device under test DUT.

[0060] When common-mode interference occurs, since the magnetic flux directions of the two coils of the common-mode inductor T1 are the same, the total inductance increases rapidly after coupling, so the common-mode inductor T1 presents a large inductive reactance to the common-mode signal, making it difficult for the common-mode interference to pass. Therefore, the fourth capacitor C4, the fifth capacitor C5 and the common-mode inductor T1 can reduce the common-mode interference of the constant voltage source V2 and filter the ripple of the constant voltage source V2. The capacitance value of the fourth capacitor C4 and the fifth capacitor C5 can be 2.2uF, and the specific capacitance value of the fourth capacitor C4 and the fifth capacitor C5 can be adjusted according to actual needs, and the embodiment of the utility model is not limited here.

[0061] Based on the above embodiments, optionally, continue to refer to Figure 6 The power device test device further includes a resistive load R_laod, an inductive load L_laod, a first relay 16 and a second relay 17. The resistive load R_laod and the first relay 16 are connected in series between the first end of the first switch module 11 and the first power supply end VCC1 of the first power supply module 14; the inductive load L_laod is connected in series with the second relay 17, and is connected in parallel between the two ends of the resistive load R_laod and the first relay 16.

[0062] Specifically, by controlling the on or off of the first relay 16 and the second relay 17, the load in the test device can be selected to be one of a resistive load and an inductive load, so that the on-resistance and dynamic threshold voltage of the device under test DUT under different loads can be tested.

[0063] Based on the above embodiments, optionally, continue to refer to Figure 6 The power device test device also includes a current sampling module 20, a first end of the current sampling module 20 is connected to a second end of the device under test DUT, and a second end of the current sampling module 20 is grounded, for collecting a drain-source current Ids of the device under test DUT.

[0064] It can be understood that the current sampling module 20 can be an additional current measuring instrument, or a current sampling module integrated on the same circuit board as the device under test DUT, or a processor chip with a current sampling pin. The specific method can be determined according to the needs of the actual test scenario, as long as it can be used to collect the current between the drain and source of the device under test.

[0065] In some embodiments, the current sampling module 20 includes a sampling resistor Rs1. Since the sampling resistor Rs1 is connected in series with the device under test DUT, the drain-source current Ids of the device under test DUT is equal to the current flowing through the sampling resistor Rs1. Further, by collecting the voltage drop across the sampling resistor Rs1, the current flowing through the sampling resistor Rs1 is obtained by Ohm's law, and then the drain-source current Ids of the device under test DUT is obtained.

[0066] Figure 7 FIG. 1 is a schematic diagram of the structure of another power device testing device provided by an embodiment of the utility model. Figure 7 As shown, the testing device includes: a first switch module 11 , a second switch module 12 and a clamping module 13 .

[0067] The first switch module 11 includes a first drive unit 110 and a first transistor Q1. The control end of the first drive unit 110 is connected to the first PWM control signal PWM_G1. The second switch module 12 includes a second drive unit 120, a first resistor unit 121, a first diode D1, a second diode D2, and a second transistor Q2. The control end of the second drive unit 120 is connected to the second PWM control signal PWM_G2. The second switch module 12 also includes a third drive unit 122; the control end of the third drive unit 122 is connected to the third PWM control signal PWM_G3.

[0068] Optionally, the clamping module 13 includes a third switch module 130, an oscillation suppression module 131 and a filter module 132. The control end of the third switch module 130 is connected to the fourth PWM control signal PWM_G4. The third switch module 130 includes a fourth driving unit 1301 and a third transistor Q3. The oscillation suppression module 131 includes a third diode D3 and a fourth diode D4. The filter module 132 includes a first capacitor C1 and a first resistor R1.

[0069] Optionally, the power device test device further includes a first power module 14 and a second power module 15. The first power module 14 includes an adjustable voltage source V1, a first capacitor C1 and a second capacitor. The second power module 15 includes a constant voltage source V2, a fourth capacitor C4, a fifth capacitor C5 and a common mode inductor T1.

[0070] The power device testing device further includes a resistive load R_laod, an inductive load L_laod, a first relay 16 and a second relay 17 .

[0071] Optionally, the power device testing device also includes a main control module 18, which is used to output a PWM control signal to control the device under test DUT to be in different working modes, wherein the working modes include hard on and hard off mode, hard on and soft off mode, soft on and soft off mode, and soft on and hard off mode.

[0072] Specifically, the main control module 18 can be implemented by using control devices such as a micro controller unit (MCU), a digital signal processor (DSP), and a field programmable gate array (FPGA).

[0073] The PWM control signal includes a first PWM control signal PWM_G1 , a second PWM control signal PWM_G2 , a third PWM control signal PWM_G3 , and a fourth PWM control signal PWM_G4 .

[0074] The operating mode in which the drain-source voltage Vds and the drain-source current Ids are not zero during the turn-on and turn-off processes of the device under test DUT is the hard-on or hard-off mode of the device under test DUT.

[0075] The operating mode in which the drain-source voltage Vds of the device under test DUT changes from high to low and the drain-source current Ids remains constant is the soft-on mode of the device under test DUT. The operating mode in which the drain-source current Ids of the device under test DUT changes from high to low and the drain-source voltage Vds remains constant is the soft-off mode of the device under test DUT.

[0076] In some embodiments, the main control module 18 is further used to determine the dynamic on-resistance of the device under test DUT according to the drain-source voltage Vds and the drain-source current Ids of the device under test DUT. The main control module 18 is further used to determine the dynamic threshold voltage of the device under test DUT according to the gate-source voltage Vgs and the drain-source current Ids of the device under test DUT.

[0077] In some embodiments, the test device further includes a display module, which is in communication with the main control module 18 (not shown in the figure). The tester can select the load of the device under test DUT as one of the resistive load R_load and the inductive load L_load from the display module according to actual needs, so that the display module sends a load selection instruction to the main control module 18, and the main control module 18 controls the first relay 16 or the second relay 17 to close according to the load selection instruction.

[0078] After selecting the load carried by the device under test DUT, the tester can select the working mode of the device under test DUT from the display module, so that the display module sends a working mode selection instruction to the main control module 18. The main control module 18 outputs the first PWM control signal PWM_G1, the second PWM control signal PWM_G2, the third PWM control signal PWM_G3 and the fourth PWM control signal PWM_G4 according to the working mode selection instruction, so as to control the first transistor Q1, the second transistor Q2, and the third transistor Q3 to be turned on or off, so that the device under test DUT is in different working modes, and then the dynamic on-resistance and dynamic threshold voltage of the device under test DUT in different working modes can be tested.

[0079] After selecting the working mode of the device under test DUT, the output voltage of the first power module 14 can also be changed, so as to test the influence of different drain-source voltages Vds on the dynamic threshold voltage of the device under test DUT. In addition, by setting the first power module 14 to provide different DC voltages for the device under test DUT, the dynamic saturation current of the device under test DUT under different DC voltages, i.e., different drain-source voltages and the same pulse width can be tested. It is also possible to control the gate drive voltage VCC_G4 to apply different gate-source voltages Vgs to the gate of the device under test DUT, and then determine the dynamic on-resistance and dynamic threshold voltage of the device under test DUT under different gate-source voltages Vgs.

[0080] Figure 8 This is a waveform diagram of a device under test in a hard-on and hard-off mode provided by an embodiment of the utility model, such as Figure 8 As shown, from time 0 to the first time t1, the transistors are all turned off, and the drain-source voltage Vds of the device under test DUT is 0.

[0081] From the first time t1 to the second time t2, and from the third time t3 to the fourth time t4, the first transistor Q1 and the second transistor Q2 are controlled to be turned on, and the third transistor Q3 and the device under test DUT are controlled to be turned off.

[0082] From the second time t2 to the third time t3, the device under test DUT and the third transistor Q3 are controlled to be turned on, and the first transistor Q1 and the second transistor Q2 are controlled to be turned off, so as to test the dynamic on-resistance of the device under test DUT.

[0083] At the fifth moment t5, the drain-source current Ids of the device under test DUT is equal to the set current, and at this time, the gate-source voltage Vgs of the device under test is the dynamic threshold voltage.

[0084] Fig. 9 This is a waveform diagram of a device under test in a hard-on and soft-off mode provided by an embodiment of the utility model, such as Fig. 9As shown, from time 0 to the first time t1, the first transistor Q1 and the second transistor Q2 are controlled to be turned on, and the third transistor Q3 and the device under test DUT are controlled to be turned off.

[0085] From the first time t1 to the second time t2, the first transistor Q1, the second transistor Q2, the third transistor Q3 and the device under test DUT are all controlled to be turned on.

[0086] From the second time t2 to the third time t3, the second transistor Q2, the third transistor Q3 and the device under test DUT are controlled to be turned on, and the first transistor Q1 is controlled to be turned off.

[0087] From the first moment t1 to the third moment t3, the dynamic on-resistance of the device under test DUT is tested. At the second moment t2, the drain-source current Ids of the device under test DUT is equal to the set current, and at this time, the gate-source voltage Vgs of the device under test is the dynamic threshold voltage.

[0088] Fig.10 This is a waveform diagram of a device under test in a soft-on and hard-off mode provided by an embodiment of the utility model, such as Fig.10 As shown, from time 0 to the first time t1, the transistors are all turned off, and the drain-source voltage Vds of the device under test DUT is 0.

[0089] From the first moment t1 to the third moment t3, the second transistor Q2, the third transistor Q3 and the device under test DUT are controlled to be turned on, and the first transistor Q1 is controlled to be turned off.

[0090] From the third time t3 to the fourth time t4, the first transistor Q1 and the second transistor Q2 are controlled to be turned on, and the third transistor Q3 and the device under test DUT are controlled to be turned off.

[0091] From the first moment t1 to the third moment t3, the dynamic on-resistance of the device under test DUT is tested. At the fifth moment t5, the drain-source current Ids of the device under test DUT is equal to the set current, and the gate-source voltage Vgs of the device under test is the dynamic threshold voltage.

[0092] Fig.11 This is a waveform diagram of a device under test in a soft-on and soft-off mode provided by an embodiment of the utility model, such as Fig.11 As shown, the transistors are all turned off, and the drain-source voltage Vds of the device under test DUT is 0.

[0093] From the first time t1 to the second time t2, the second transistor Q2, the third transistor Q3 and the device under test DUT are controlled to be turned on, and the first transistor Q1 is controlled to be turned off.

[0094] From the second time t2 to the third time t3, the first transistor Q1, the second transistor Q2, the third transistor Q3 and the device under test DUT are all controlled to be turned on.

[0095] From the third time t3 to the fourth time t4, the second transistor Q2, the third transistor Q3 and the device under test DUT are controlled to be turned on, and the first transistor Q1 is controlled to be turned off.

[0096] From the first moment t1 to the third moment t3, the dynamic on-resistance of the device under test DUT is tested. At the third moment t3, the drain-source current Ids of the device under test DUT is equal to the set current, and the gate-source voltage Vgs of the device under test is the dynamic threshold voltage.

[0097] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A power device testing device, characterized in that: include: A first switch module, a second switch module and a clamp module; The first switch module is connected to the first end of the device under test, and the first switch module is used to control the pressure application time of the DC voltage to determine the changes of the dynamic threshold voltage and the dynamic on-resistance of the device under test under different pressure application time; The second switch module is connected to the first terminal, the second terminal and the control terminal of the device under test, and the second switch module is used to control the device under test to be turned on or off, and when the drain-source current of the device under test is equal to the set current, the gate-source voltage of the device under test is a dynamic threshold voltage; The first end of the clamp module is connected to the first end of the device under test, and the second end of the clamp module is connected to the second end of the device under test. The clamp module is used to clamp the drain-source voltage of the device under test and output it.

2. The power device testing device according to claim 1, characterized in that: The first switch module includes a first driving unit and a first transistor; A control end of the first driving unit is connected to a first PWM control signal, a first end of the first driving unit is connected to a gate electrode of the first transistor, a second end of the first driving unit is connected to a second electrode of the first transistor, and the first driving unit is used to control the first transistor to be turned on or off according to the first PWM control signal; A first electrode of the first transistor is connected to a first power supply terminal, and a second electrode of the first transistor is connected to a first terminal of the device under test; and / or, The second switch module includes a second driving unit, a first resistance unit, a first diode, a second diode and a second transistor; A control end of the second driving unit is connected to a second PWM control signal, a first end of the second driving unit is connected to a gate of the second transistor, a second end of the second driving unit is connected to a second electrode of the second transistor, and the second driving unit is used to control the on or off of the second transistor according to the second PWM control signal; The first end of the first resistor unit is connected to the second power supply end, and the second end of the first resistor unit is connected to the anode of the first diode and the anode of the second diode respectively; The cathode of the first diode is connected to the first end of the device under test, and the cathode of the second diode is connected to the first electrode of the second transistor.

3. The power device testing device according to claim 2, characterized in that: The second switch module further includes a third driving unit; The control end of the third driving unit is connected to the third PWM control signal, the first end of the third driving unit is connected to the second electrode of the second transistor, the second end of the third driving unit is connected to the second end of the device under test, and the third driving unit is used to control the device under test to be turned on or off according to the third PWM control signal; The power supply terminal of the third driving unit is connected to a gate driving voltage, and the gate driving voltage is adjustable.

4. The power device testing device according to claim 1, characterized in that: The clamping module includes a third switch module, an oscillation suppression module and a filtering module. The control end of the third switch module is connected to the fourth PWM control signal, the first end of the third switch module is connected to the first end of the device under test, the second end of the third switch module is connected to the first end of the oscillation suppression module, and the third switch module is used to block the drain-source voltage of the device under test in the off state; The second end of the oscillation suppression module is connected to the second end of the device under test, and is used to limit the drain-source voltage oscillation caused by switching noise; The filtering module is connected in parallel with the oscillation suppression module and is used to filter out noise generated by the third switch module during the switching process.

5. The power device testing device according to claim 4, characterized in that: The third switch module includes a fourth driving unit and a third transistor; The control end of the fourth driving unit serves as the control end of the third switch module, the first electrode of the third transistor serves as the first end of the third switch module, and the second electrode of the third transistor serves as the second end of the third switch module; A first end of the fourth driving unit is connected to the gate of the third transistor, a second end of the fourth driving unit is connected to the second electrode of the third transistor, and the fourth driving unit is used to control the third transistor to be turned on or off according to the fourth PWM control signal.

6. The power device testing device according to claim 4, characterized in that: The oscillation suppression module includes a third diode and a fourth diode; The anode of the third diode is connected to the cathode of the fourth diode and serves as the first end of the oscillation suppression module, and the cathode of the third diode is connected to the anode of the fourth diode and serves as the second end of the oscillation suppression module; and / or, The filtering module includes a first capacitor and a first resistor, and the oscillation suppression module is connected in parallel with the first capacitor and the first resistor respectively.

7. The power device testing device according to claim 1, characterized in that: Also includes a first power module and a second power module; The first power supply module is connected to the first switch module, and the first power supply module is used to provide different DC voltages for the device under test; The second power supply module is connected to the second switch module and the device under test respectively, and the second power supply module provides a constant current to the device under test.

8. The power device testing device according to claim 7, characterized in that: Also includes a resistive load, an inductive load, a first relay and a second relay; The resistive load and the first relay are connected in series between the first end of the first switch module and the first power supply end of the first power supply module; The inductive load is connected in series with the second relay, and is connected in parallel between the resistive load and the two ends of the first relay.

9. The power device testing device according to claim 1, characterized in that: It also includes a current sampling module, a first end of which is connected to a second end of the device under test, and a second end of which is grounded, for collecting drain-source current of the device under test.

10. The power device testing device according to any one of claims 1 to 9, characterized in that: It also includes a main control module, which is used to output a PWM control signal to control the device under test to be in different working modes, wherein the working modes include hard-on and hard-off mode, hard-on and soft-off mode, soft-on and soft-off mode, and soft-on and hard-off mode.

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