A GaN HEMT Power Device Gate Degradation Detection Device and Method

Abstract

The present invention discloses a gate degradation detection device and method for a GaN HEMT power device, belonging to the technical field of performance detection, including a pulse excitation source, a passive circuit, a sampling circuit, a controller and a driving circuit; the pulse excitation source is connected to the GaN HEMT power device to be measured through the passive circuit, the output end of the sampling circuit is connected to the input end of the controller, and the output end of the controller is connected to the control end of the pulse excitation source through the driving circuit. The controller collects the voltage signal between the source and the gate in the GaN HEMT power device to be measured through the sampling circuit V GS , and judges the degradation degree of the gate in the GaN HEMT power device to be measured according to the voltage signal V GS . The device and method can detect the degradation degree of the gate of the GaN HEMT power device, and have the characteristics of simple operation and low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of performance detection, and relates to a gate degradation detection device and method for GaN HEMT power devices. Background Art

[0002] As the core device of the new energy industry, the reliability of power electronic devices has become a key factor in the development of new energy. Power semiconductor devices are the key components of power electronic devices, and traditional silicon-based power semiconductor devices are difficult to meet the current diverse application requirements. In contrast, GaN HEMT (High Electron Mobility Transistors) power devices exhibit excellent performance in high-frequency, high-temperature, and low-power application scenarios due to their higher electron mobility and wider bandgap.

[0003] However, the gates of GaN HEMT power devices mostly adopt a metal-semiconductor Schottky contact structure, which is significantly different from the metal-oxide-semiconductor insulated gate structure of traditional SiMOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). This structural characteristic results in relatively limited voltage withstand capacity, usually only able to withstand a voltage range of -10V to +7V. In high-frequency switching operation scenarios, the parasitic inductance L G and Miller capacitance C GD coupling effect can cause overshoot or oscillation of the driving voltage, and the overshoot voltage may exceed the safe operating voltage of the gate. Under such electrical stress for a long time, the high electric field will accelerate the accumulation of gate interface state defects until the p-GaN (p-type gallium nitride) gate and the passivation interface are damaged, and then a percolation path is formed. The gate leakage current after gate breakdown exhibits a resistance-like characteristic, showing that the gate-source equivalent resistance gradually degrades from the normal megaohm level to the kiloohm or even hundred-ohm level.

[0004] Currently, although there are several methods for detecting gate degradation, such as electrical parameter detection methods based on monitoring the threshold voltage or gate leakage current, optical detection methods based on electroluminescence imaging, etc., these methods generally have problems of complex operation or high cost. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned drawbacks of the prior art, and provide a gate degradation detection device and method for GaN HEMT power devices, which can detect the degree of gate degradation of GaN HEMT power devices and have the characteristics of simple operation and low cost.

[0006] To achieve the above object, the present invention discloses a gate degradation detection device for a GaN HEMT power device, comprising a pulse excitation source, a passive circuit, a sampling circuit, a controller and a drive circuit;

[0007] The pulse excitation source is connected to the GaN HEMT power device to be measured through the passive circuit. The output end of the sampling circuit is connected to the input end of the controller, and the output end of the controller is connected to the control end of the pulse excitation source through the drive circuit. The controller collects the voltage signal between the source and the gate in the GaN HEMT power device to be measured through the sampling circuit V GS and determines the degradation degree of the gate in the GaN HEMT power device to be measured according to the voltage signal V GS .

[0008] A further improvement of the gate degradation detection method for the GaN HEMT power device of the present invention lies in:

[0009] Furthermore, the passive circuit includes a first resistor, a diode, a second resistor, a third resistor, a first capacitor and a second capacitor. The pulse excitation source, the first resistor, the diode and the second resistor are sequentially connected in series to form a series loop. The series branch formed by the third resistor and the first capacitor in series is connected in parallel with the first resistor. The second capacitor is connected in parallel with the second resistor. The series branch formed by the diode and the second resistor in series is connected in parallel with the GaN HEMT power device to be measured.

[0010] Furthermore, it further includes an auxiliary power supply for supplying electrical energy to the sampling circuit, the controller and the drive circuit.

[0011] The present invention discloses a gate degradation detection method for a GaN HEMT power device, comprising the following steps:

[0012] The controller outputs a control signal V 0 to the drive circuit, and the drive circuit generates a pulse excitation voltage signal according to the control signal V 0 V PULSE . The pulse excitation voltage signal V PULSE is applied to the gate and the source of the GaN HEMT power device to be measured through the passive circuit. The voltage signal between the gate and the source in the GaN HEMT power device to be measured is obtained through the sampling circuit V GS , the response voltage when the gate in the GaN HEMT power device to be measured is not degraded is calculated V GS-CALC , and then the voltage signal V GS is compared with the response voltageV GS-CALC , determine whether the gate of the GaN HEMT power device under test is degraded according to the comparison result;

[0013] When the gate of the GaN HEMT power device under test is degraded, then according to the voltage signal V GS obtain the measured voltage platform value of this voltage signal V GS ; V GS-H and the measured voltage peak value V GS-MAX ;

[0014] According to the measured voltage platform value V GS of the voltage signal V GS-H and the measured voltage peak value V GS-MAX judge the degradation degree of the gate in the GaN HEMT power device.

[0015] A further improvement of the method for detecting the degradation of the gate of the GaN HEMT power device according to the present invention lies in:

[0016] Further, the response voltage when the gate in the GaN HEMT power device under test is not degraded V GS-CALC is:

[0017]

[0018] wherein, V D is the voltage drop of the diode, s is a complex variable, R 1 is the resistance value of the first resistor, R 2 is the resistance value of the second resistor, R 3 is the resistance value of the third resistor, C 1 is the capacitance value of the first capacitor, C 2 is the capacitance value of the second capacitor, C GS is the capacitance value of the capacitance between the gate and the source in the GaN HEMT power device under test, R GS is the resistance value of the gate-source equivalent resistance of the GaN HEMT power device under test.

[0019] Further, when the voltage signal V GS and the response voltage V GS-CALCWhen the deviation is greater than the preset deviation threshold, it is considered that the gate of the GaN HEMT power device under test has degraded.

[0020] Further, according to the voltage signal V GS of the measured voltage platform value V GS-H and the measured voltage peak value V GS-MAX The process of judging the degradation degree of the gate in the GaN HEMT power device is as follows:

[0021] According to the voltage signal V GS of the measured voltage platform value V GS-H Judge the degradation degree of the gate-source equivalent resistance in the GaN HEMT power device under test;

[0022] According to the voltage signal V GS of the measured voltage peak value V GS-MAX Judge the degradation degree of the capacitance between the gate and the source in the GaN HEMT power device under test.

[0023] Further, the measured voltage platform value of the voltage signal V GS is lower, the more serious the degradation degree of the gate-source equivalent resistance in the GaN HEMT power device under test. V GS-H The lower the measured voltage platform value of the voltage signal

[0024] Further, the measured voltage peak value of the voltage signal V GS is higher, the more serious the degradation degree of the capacitance between the gate and the source in the GaN HEMT power device under test. V GS-MAX The higher the measured voltage peak value of the voltage signal

[0025] Further, it also includes an auxiliary power supply, which provides electrical energy for the sampling circuit, the controller and the drive circuit.

[0026] The present invention has the following beneficial effects:

[0027] When the GaN HEMT power device gate degradation detection device and method of the present invention are specifically operated, the controller outputs a control signal V 0 to the drive circuit, and the drive circuit generates a pulse excitation voltage signal according to the control signal V 0 V PULSE and outputs the pulse excitation voltage signal VPULSE Applied to the gate and source of the GaN HEMT power device to be tested to obtain a response signal, that is, the voltage signal between the gate and the source in the GaN HEMT power device to be tested V GS , according to the voltage signal between the gate and the source in the GaN HEMT power device to be tested V GS , determine whether the gate of the GaN HEMT power device to be tested is degraded and the degree of degradation. The operation is simple and highly practical. At the same time, it avoids using the electrical parameter detection method based on monitoring the threshold voltage or gate leakage current and the optical detection method based on electroluminescence imaging, with relatively low cost. It should be noted that in the present invention, the process from the controller sending out a control signal V 0 generating a pulsed excitation voltage to collecting the response voltage signal only takes hundreds of μs, and the gate degradation detection speed is relatively fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 is the circuit diagram of the detection circuit in the present invention;

[0030] Figure 2 is the schematic diagram of the control circuit in the present invention;

[0031] Figure 3a is the control signal V 0 waveform diagram;

[0032] Figure 3b is the pulsed excitation voltage signal V PULSE waveform diagram;

[0033] Figure 3c is the voltage signal V GS waveform diagram;

[0034] Figure 3d is the sampling signal V GS-Sampling waveform diagram;

[0035] Figure 4 is the schematic diagram of the response voltage V of the GaN HEMT power device under different gate degradation degrees GS-OUT schematic diagram.

[0036] Among them, 1 is a controller, 2 is a drive circuit, 3 is an auxiliary power supply, 4 is a sampling circuit, W is a pulse excitation source, G1 is a first resistor, S is a diode, G2 is a second resistor, G3 is a third resistor, D1 is a first capacitor, and D2 is a second capacitor. Specific embodiments

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be understood that the terms "include" and "comprise" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0039] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0040] It should be further understood that the term " / and" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations. For example, A and / or B may represent: the case of A alone, the case of A and B existing simultaneously, and the case of B alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the contextually related objects.

[0041] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present invention to describe preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0042] Depending on the context, as used herein, the word "if" can be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. The components of the present invention described and shown in the drawings herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0044] Schematic diagrams of various structures according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes and relative positions according to actual needs.

[0045] Embodiment 1

[0046] Reference Figure 1 And Figure 2 , the gate degradation detection device of the GaN HEMT power device described in the present invention includes a pulse excitation source W, a passive circuit, a sampling circuit 4, a controller 1, an auxiliary power supply 3 and a driving circuit 2; the pulse excitation source W is connected to the GaN HEMT power device L to be measured through the passive circuit, and the sampling circuit 4 is used to collect the voltage signal between the source and the gate in the GaN HEMT power device L to be measured V GS , the output end of the sampling circuit 4 is connected to the input end of the controller 1, and the output end of the controller 1 is connected to the control end of the pulse excitation source W through the driving circuit 2. The controller is based on the voltage signal between the source and the gate in the GaN HEMT power device L collected by the sampling circuit 4 V GSDetermine the degradation degree of the gate of the GaN HEMT power device.

[0047] Embodiment 2

[0048] Reference Figure 1 And Figure 2 For the GaN HEMT power device gate degradation detection device of the present invention, it includes a pulse excitation source W, a passive circuit, a sampling circuit 4, a controller 1, an auxiliary power supply 3 and a drive circuit 2. The passive circuit includes a first resistor G1, a diode S, a second resistor G2, a third resistor G3, a first capacitor D1 and a second capacitor D2;

[0049] The pulse excitation source W, the first resistor G1, the diode S and the second resistor G2 are connected in series in sequence to form a series loop. The series branch formed by the third resistor G3 and the first capacitor D1 is connected in parallel with the first resistor G1. The second capacitor D2 is connected in parallel with the second resistor G2. The series branch formed by the diode S and the second resistor G2 is connected in parallel with the GaN HEMT power device L to be measured.

[0050] The sampling circuit 4 is used to collect the voltage signal between the source and the gate in the GaN HEMT power device L to be measured V GS ; The output end of the sampling circuit 4 is connected to the input end of the controller 1, and the output end of the controller 1 is connected to the control end of the pulse excitation source W through the drive circuit 2.

[0051] In this embodiment, it further includes an auxiliary power supply 3 for providing electric energy. Among them, the auxiliary power supply 3 is connected to the power supply interfaces of the drive circuit 2, the sampling circuit 4 and the controller 1, and is used to provide 12V voltage for the drive circuit 2, ±5V voltage for the sampling circuit 4, and 3.3V voltage for the controller 1. As Figure 3a shown, the amplitude of the control signal V 0 is 3.3V; as Figure 3b shown, the amplitude of the pulse excitation voltage signal V PULSE is 12V.

[0052] During operation, the controller 1 generates a control signal V 0, and outputs the control signal V 0 to the drive circuit 2. The drive circuit 2 generates a pulse excitation voltage signal V 0 according to the control signal V PULSE , and inputs the pulse excitation voltage signal V PULSE into the pulse excitation source W to control the pulse excitation source W. The sampling circuit 4 collects the voltage signal between the source and the gate in the GaN HEMT power device L to be measuredV GS , and then condition the voltage signal V GS to obtain a sampled signal within the voltage range of 0 - 3.3V V GS-Sampling , and then output the sampled signal V GS-Sampling to Controller 1. When Controller 1 does not generate a control signal, the voltage between the source and the gate in the GaN HEMT power device L to be measured is zero.

[0053] Embodiment III

[0054] Reference Figure 1 and Figure 2 , this embodiment discloses a method for detecting gate degradation of a GaN HEMT power device. The method for detecting gate degradation of the GaN HEMT power device is implemented based on the system for detecting gate degradation of the GaN HEMT power device. The system for detecting gate degradation of the GaN HEMT power device includes a pulse excitation source W, a passive circuit, a sampling circuit 4, a controller 1, an auxiliary power supply 3, and a driving circuit 2. The passive circuit includes a first resistor G1, a diode S, a second resistor G2, a third resistor G3, a first capacitor D1, and a second capacitor D2. The specific connection relationship is as shown in Embodiment II.

[0055] Specifically, the method for detecting gate degradation of the GaN HEMT power device includes the following steps:

[0056] 1) The controller 1 outputs a control signal V 0 to the driving circuit 2. The driving circuit 2 generates a pulsed excitation voltage signal V 0 according to the control signal V PULSE , which is applied to the gate and the source of the GaN HEMT power device L to be measured through the passive circuit. The voltage signal between the gate and the source in the GaN HEMT power device L to be measured is obtained through the sampling circuit 4 V GS , the response voltage when the gate of the GaN HEMT power device L to be measured is not degraded is calculated V GS-CALC , and the voltage signal V GS is compared with the response voltage V GS-CALC , and it is determined whether the gate of the GaN HEMT power device L to be measured is degraded according to the comparison result;

[0057] 2) When the gate of the GaN HEMT power device L to be measured is not degraded, the process ends;

[0058] 3) When the gate of the GaN HEMT power device L to be tested is degraded, the voltage signal between the gate and the source of the GaN HEMT power device L to be tested is detected. V GS The voltage signal is obtained by V GS The measured voltage platform value V GS-H and peak V GS-MAX ,like Figure 3c As shown, the voltage signal V GS Conditioning is performed to obtain a sampling signal within the voltage range of 0-3.3V V GS-Sampling , Figure 3d As shown, by conditioning, the voltage signal is simply changed V GS The amplitude of the sampling signal is not changed. V GS-Sampling With voltage signal V GS Related.

[0059] According to the voltage signal V GS The measured voltage platform value V GS-H Determine the degradation degree of the gate-source equivalent resistance in the GaN HEMT power device L to be tested;

[0060] According to the voltage signal V GS The measured voltage peak V GS-MAX Determine the degree of degradation of the capacitance between the gate and the source in the GaN HEMT power device L to be tested.

[0061] It should be noted that, in this embodiment, when the gate of the GaN HEMT power device L is not degraded, the voltage between the gate and the source of the GaN HEMT power device L to be tested is V GS-CALC for:

[0062]

[0063] in, V D is the voltage drop of diode S, s is a complex variable representing the frequency in the Laplace transform domain, R 1 is the resistance value of the first resistor G1, R 2 is the resistance value of the second resistor G2, R3 is the resistance value of the third resistor G3, C 1 is the capacitance value of the first capacitor D1, C 2 is the capacitance value of the second capacitor D2, C GS is the capacitance value of the capacitance between the gate and the source in the GaN HEMT power device L to be measured, R GS is the resistance value of the gate-source equivalent resistance of the GaN HEMT power device L to be measured.

[0064] In addition, it should be noted that in step 1), when the voltage signal V GS and the response voltage V GS-CALC have a deviation greater than the preset deviation threshold, it indicates that the gate of the GaN HEMT power device L to be measured is degraded. Among them, the greater the deviation, the more serious the degradation of the gate.

[0065] In this embodiment, in step 3), referring to Figure 4 , as the resistance value R GS of the gate-source equivalent resistance of the GaN HEMT power device L to be measured becomes smaller, the measured voltage platform value V GS of the voltage signal V GS-H is lower, and the measured voltage platform value V GS of the voltage signal V GS-H is lower, which indicates that the degradation degree of the gate-source equivalent resistance in the GaN HEMT power device L to be measured is more serious. In addition, the higher the measured voltage peak value V GS of the voltage signal V GS-MAX and the more serious the deformation of the voltage signal V GS , the more serious the degradation degree of the capacitance between the gate and the source in the GaN HEMT power device L to be measured.

[0066] It should be noted that the present invention has the following characteristics:

[0067] The present invention uses a passive circuit to convert the changes in the gate equivalent resistance and the parasitic capacitance between poles into the characteristic differences of the voltage waveform. After the controller 1 collects the response voltage signal, it can perform operations and judge the degradation degree of the gate. The process from the controller 1 sending a control signal to generate a pulse excitation voltage to collecting the response voltage signal only takes hundreds of μs, and the gate degradation detection speed is relatively fast.

[0068] Secondly, the present invention does not need to rely on high-precision parameter analyzers or optical devices, has a low cost, and is relatively simple to operate.

[0069] Finally, the present invention establishes a mapping relationship between voltage waveform parameters and the degree of degradation based on theoretical formulas, supports the determination of the full life cycle state from early slight degradation to severe failure, and provides direct data support for the prediction of the remaining life of the device.

[0070] Those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and the disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include known common knowledge or conventional technical means in the technical field not disclosed by the present invention. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the following claims.

[0071] It should be understood that the present invention is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

[0072] The above are only the preferred embodiments of the present invention, and do not limit the present invention in any way. Any simple modifications, changes, and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for detecting gate degradation of a GaN HEMT power device, characterized in that, GaN HEMT power device gate degradation detection device, the GaN HEMT power device gate degradation detection device includes a pulse excitation source (W), a passive circuit, a sampling circuit (4), a controller (1) and a drive circuit (2); The pulse excitation source (W) is connected to the GaN HEMT power device (L) to be measured through a passive circuit. The output end of the sampling circuit (4) is connected to the input end of the controller (1). The output end of the controller (1) is connected to the control end of the pulse excitation source (W) through the drive circuit (2). The controller (1) collects the voltage signal between the source and the gate in the GaN HEMT power device (L) to be measured through the sampling circuit (4). V GS and determines the degradation degree of the gate in the GaN HEMT power device (L) to be measured according to the voltage signal V GS ; The passive circuit includes a first resistor (G1), a diode (S), a second resistor (G2), a third resistor (G3), a first capacitor (D1) and a second capacitor (D2). The pulse excitation source (W), the first resistor (G1), the diode (S) and the second resistor (G2) are connected in series in turn to form a series loop. The series branch formed by the third resistor (G3) and the first capacitor (D1) is connected in parallel with the first resistor (G1). The second capacitor (D2) is connected in parallel with the second resistor (G2). The series branch formed by the diode (S) and the second resistor (G2) is connected in parallel with the GaN HEMT power device to be measured (L); Comprising the following steps: The controller (1) outputs a control signal V to the drive circuit (2), and the drive circuit (2) generates a pulse excitation voltage signal V according to the control signal V PULSE . The pulse excitation voltage signal V PULSE is applied to the gate and source of the GaN HEMT power device (L) to be measured through a passive circuit, and a voltage signal between the gate and source in the GaN HEMT power device (L) to be measured is obtained through the sampling circuit (4). V GS The response voltage when the gate of the GaN HEMT power device (L) to be measured is not degraded is calculated V GS-CALC . Then, the voltage signal V GS is compared with the response voltage V GS-CALC . Whether the gate of the GaN HEMT power device (L) to be measured is degraded is judged according to the comparison result. When the gate of the GaN HEMT power device (L) to be measured degrades, the measured voltage platform value V GS and the measured voltage peak value V GS of the voltage signal are obtained according to the waveform of the voltage signal V GS-H ; V GS-MAX ​ According to the voltage signal V GS of the measured voltage platform value V GS-H and the measured voltage peak value V GS-MAX judge the degradation degree of the gate in the GaN HEMT power device; The response voltage of the GaN HEMT power device (L) to be measured when the gate is not degraded V GS-CALC is as follows: Among them, V D is the voltage drop of the diode (S), s is a complex variable, R 1 is the resistance value of the first resistor (G1), R 2 is the resistance value of the second resistor (G2), R 3 is the resistance value of the third resistor (G3), C 1 is the capacitance value of the first capacitor (D1), C 2 is the capacitance value of the second capacitor (D2), C GS is the capacitance value of the capacitance between the gate and the source in the GaN HEMT power device (L) to be measured, R GS is the resistance value of the gate-source equivalent resistance of the GaN HEMT power device (L) to be measured; The measured voltage plateau value V GS and the measured voltage peak value V GS-H of the voltage signal V GS-MAX The process of judging the degradation degree of the gate in the GaN HEMT power device is as follows: According to the voltage signal V GS of the measured voltage platform value V GS-H judge the degradation degree of the gate-source equivalent resistance in the GaN HEMT power device (L) to be measured; According to the voltage signal V GS of the measured voltage peak value V GS-MAX judge the degradation degree of the capacitance between the gate and the source in the GaN HEMT power device (L) to be measured.

2. The gate degradation detection method for the GaN HEMT power device according to claim 1, wherein When the voltage signal V GS and the response voltage V GS-CALC have a deviation greater than a preset deviation threshold, it is considered that the gate of the GaN HEMT power device (L) under test has degraded.

3. The method for detecting gate degradation of the GaN HEMT power device according to claim 1, wherein The voltage signal V GS of the measured voltage platform value V GS-H is lower, the more serious the degradation degree of the gate-source equivalent resistance in the GaN HEMT power device (L) to be measured.

4. The gate degradation detection method for the GaN HEMT power device according to claim 1, characterized in that, The voltage signal V GS The measured peak voltage of V GS-MAX is higher, the more serious the degradation of the capacitance between the gate and the source in the GaN HEMT power device (L) to be measured.

5. The method for detecting gate degradation of a GaN HEMT power device according to claim 1, wherein It further includes an auxiliary power supply (3), and the auxiliary power supply (3) provides electrical energy for the sampling circuit (4), the controller (1) and the drive circuit (2).

6. The method for detecting gate degradation of a GaN HEMT power device according to claim 1, characterized in that, It further includes an auxiliary power supply (3) for providing electrical energy for the sampling circuit (4), the controller (1) and the drive circuit (2).

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