Power device full-dynamic characteristic multi-parameter in-situ characterization circuit and test method

Abstract

The invention belongs to the technical field of power semiconductor device testing, and particularly relates to a power device full-dynamic characteristic multi-parameter in-situ characterization circuit and a testing method. The device comprises a high-voltage source circuit, a stress control module, a conduction characteristic network, a threshold voltage test module, a to-be-tested device and a control signal generation module. The high-voltage source circuit is used for providing bias voltage; the stress control module is used for controlling the stress applying time; the conduction characteristic network is used for representing dynamic on-resistance and transient switching characteristics; the threshold voltage test module is used for extracting dynamic threshold voltage in situ; and the control signal generation module is used for generating a driving signal for controlling the working time sequence of the circuit. According to the invention, continuous and synchronous monitoring of multiple physical parameters on the same platform can be realized, charge recovery errors caused by ex-situ testing are eliminated, and accurate data support is provided for revealing a reliability evolution mechanism and system-level application evaluation of wide bandgap semiconductor devices such as gallium nitride.

Description

Technical Field

[0001] This invention belongs to the field of power semiconductor device testing technology, specifically relating to a multi-parameter in-situ characterization circuit and testing method for the full dynamic characteristics of power devices. Background Technology

[0002] With the rapid development of wide-bandgap semiconductor materials, especially gallium nitride (GaN) technology, GaN devices have been widely used in consumer electronics, data center power supplies, electric vehicles, and aerospace due to their high switching frequency, low conduction loss, and high temperature resistance. However, the complex trap effects and interface states in the physical structure of GaN devices (such as the floating p-GaN layer in Schottky p-GaN gate HEMTs and AlGaN / GaN heterojunctions) have made their dynamic reliability under actual operating conditions a key bottleneck restricting their large-scale deployment. In power conversion topologies, power devices typically alternate between high-voltage turn-off stress and high-current conduction states. During turn-off, the strong electric field generated by the high drain-source voltage causes hot carriers to be trapped in internal device traps, resulting in charge trapping. This phenomenon directly manifests as the degradation of two key dynamic parameters: one is the dynamic on-resistance (R0). ON The increase in voltage (V) leads to a sharp rise in conduction losses, which can cause thermal runaway in severe cases; secondly, the dynamic threshold voltage (V) TH The drift of the device can change its driving characteristics, leading to increased switching losses or causing false logic triggering.

[0003] Currently, characterization methods for these dynamic characteristics still have significant limitations. First, existing characterization equipment often only measures dynamic resistance or dynamic threshold voltage individually, failing to simultaneously acquire multiple physical parameters under the same stress sequence, making it difficult to reveal the coupling relationships between different degradation mechanisms. Second, due to the recovery characteristics of trapped charges, traditional testing schemes suffer from a long switching blind zone (typically milliseconds or higher) during the transition from "stress application" to "parameter sampling." During this delay, some of the trapped charges have already been released, leading to variations in the measured R... ON or V TH The drift value is much smaller than the actual value of the device at the moment of actual switching. Thirdly, most test platforms can only simulate static voltage stress and cannot reproduce the continuous hard switching conditions in real applications. Under continuous switching stress, the device simultaneously experiences the combined impact of voltage, current, and heat, and its degradation mechanism is fundamentally different from that under static stress. Therefore, it is necessary to develop a system that can integrate multiple preset electrical stress simulations (including static and dynamic conditions), has microsecond-level switching response capability, and can extract dynamic R in situ within the same test sequence. ON V THAn integrated testing platform for multiple parameters of switching characteristics is of significant scientific and engineering value for comprehensively evaluating the reliability of power devices, optimizing circuit design, and establishing high-precision dynamic models. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing testing schemes, such as single parameter representation dimensions, data distortion caused by testing blind spots, and inability to simulate complex dynamic operating conditions. It provides a multi-parameter in-situ characterization circuit and testing method for the full dynamic characteristics of power devices. Through a highly integrated modular design, this invention enables multi-stress simulation of power devices within a single testing platform, and extracts dynamic on-resistance, dynamic threshold voltage, and transient switching characteristics in situ and in real time, providing accurate data support for the reliability assessment of power devices.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A multi-parameter in-situ characterization circuit for the full dynamic characteristics of a power device includes a high-voltage source circuit, a stress control module, a conduction characteristic network, a threshold voltage testing module, a device under test (DUT), and a control signal generation module. The high-voltage source circuit is connected to the input of the stress control module to provide a bias voltage. The stress control module is connected to the drain of the DUT to control the applied stress time. The conduction characteristic network is connected to the main power loop to characterize dynamic on-resistance and transient switching characteristics. The threshold voltage testing module is connected between the gate and drain of the DUT to extract the dynamic threshold voltage in situ. The control signal generation module is connected to the PWM input of the isolation driver in each module to generate drive signals for the control circuit's operating timing.

[0007] The high-voltage source circuit includes a DC high-voltage source V. bus The filter capacitor C1 is connected in parallel with the DC high voltage source V. bus At the output terminal, the filter capacitor C1 is used to provide a stable off-state drain bias stress for the device under test, simulating the high-voltage operating environment of an actual power converter;

[0008] The stress control module includes a bridge arm switching structure composed of bidirectional power switches S1, S3, and power switch S2, as well as isolation drivers D_S1, D_S2, and D_S3; wherein, the control terminal of S1 is connected to the output terminal of isolation driver D_S1, the control terminal of S2 is connected to the output terminal of isolation driver D_S2, and the control terminal of S3 is connected to the output terminal of isolation driver D_S3; the input terminal of S1 is connected to a DC high-voltage source V. busAt the output terminal, S1 and S3 are connected in series in the main power path, and S2 is connected between the output terminal of S3 and the common ground; by controlling the conduction and cutoff of switches S1, S3 and S2, nanosecond-level cutoff and start-up of the high voltage circuit can be achieved, and current is prevented from flowing back into the high voltage source during the test phase.

[0009] The conductive characteristic network includes a load circuit, which consists of a load resistor R1 and a load inductor L1 connected in series, and a diode D1 connected in parallel across the load circuit. The cathode of the diode D1 is connected to the load resistor R1, and the anode of the diode D1 is connected to the load inductor L1. The load resistor R1 is used to adjust the test current and is connected to the connection point of switches S1 and S3. The load inductor L1 is used to simulate the inductive load effect.

[0010] The conductive characteristic network also integrates a dynamic voltage drop monitoring unit; the dynamic voltage drop monitoring unit includes a DC power supply V. in2 The components include a current-limiting resistor R2, a Schottky diode D4, a filter capacitor C2, and a Zener diode D5. The cathode of the Schottky diode D4 is connected to the drain of the device under test and the anode of the diode D1, and the anode of the Schottky diode D4 is connected to the DC power supply V through the current-limiting resistor R2. in2 The positive terminal is used to clamp the test node voltage during device turn-off, improving the test accuracy of dynamic voltage drop; the filter capacitor C2 and the Zener diode D5 are connected in parallel, and the cathode of the Zener diode D5 is connected to the anode of the Schottky diode D4. The cathode of the Zener diode D5, the source of the device under test, and V in2 The negative terminal is connected to the public ground;

[0011] The threshold voltage test module includes a test power supply V. in1 The system comprises a test control switch S5, a constant current source I1, a drive isolation switch S4, isolation drivers D_S4, D_S5, and D_DUT, and a feedback diode branch. The feedback diode branch includes an isolation diode D2 connected in series between the output of the constant current source I1 and the drain of the device under test (DUT), and a feedback diode D3 connected between the output of the constant current source I1 and the drive isolation switch S4. The cathode of isolation diode D2 is connected to the anode of diode D1. The cathode of feedback diode D3 and the output of drive isolation switch S4 are connected to the gate of the DUT. The input of drive isolation switch S4 is connected to the output of isolation driver D_DUT, and the control terminal of drive isolation switch S4 is connected to the output of isolation driver D_S4. The control terminal of test control switch S5 is connected to the output of isolation driver D_S5, and the input terminal of test control switch S5 is connected to the test power supply V. in1 The output of the test control switch S5 is connected to the input of the constant current source I1.

[0012] The isolation diodes D2 and D3 are high-voltage, fast-recovery diodes with their cathodes pointing towards the drain and gate of the device under test. During the stress application phase, D2 is in a reverse cutoff state to shield the high voltage from impacting the test circuit, and D3 is used to prevent the drive output current from being shunted by the test branch. During the test phase, D2 and D3 are synchronously turned on to construct an adaptive feedback loop.

[0013] Furthermore, the control signal generation module includes a function signal generator and logic gate circuits 1, 2, and 3 connected thereto; logic gate circuit 1 outputs complementary drive signals S1 and S2; logic gate circuit 2 outputs in-phase drive signals S3 and S4, which are opposite to the drive signal S5 output by logic gate circuit 3. All signals are provided with a certain time delay to reduce crosstalk during synchronous switching.

[0014] A method for in-situ testing of multiple parameters of the full dynamic characteristics of power devices includes the following steps:

[0015] Stress preset stage: The stress control module controls S1 to turn on and S2 to turn off, so that the device under test is subjected to off-state drain bias stress for a set time.

[0016] Switching characteristics and dynamic on-resistance testing phase: Keep S1 and S4 on, drive the device under test to work in switching mode through the control signal generation module; use the dynamic voltage drop monitoring unit to collect the voltage drop waveform across the drain and source, and combine the drain and source current to characterize the dynamic on-resistance and switching characteristics.

[0017] Dynamic threshold voltage test phase: S1 is turned off and S2 is turned on, then S3 and S4 are turned off and S5 is turned on; constant current source I1 constructs a feedback loop through D3 and D2 to lock the gate voltage of the device under test at the dynamic threshold voltage and sample it.

[0018] The test method uses a control signal generator to provide multi-pulse signals to make the device under test operate in continuous switching mode, thereby achieving in-situ evaluation of multiple parameters of the device after continuous switching stress.

[0019] The test method obtains the evolution law of the dynamic characteristics of power devices affected by voltage, time, frequency and temperature by adjusting the voltage amplitude, stress time, switching frequency and ambient temperature of the high voltage source circuit.

[0020] The beneficial effects of this invention are that, through deep coupling and timing coordination of various circuit modules, it solves the pain points of traditional testing, such as limited parameter characterization dimensions and blind spots during stress switching to the sampling stage. This invention not only enables continuous and synchronous monitoring of multiple physical parameters on the same platform, but also eliminates charge recovery errors caused by non-in-situ testing, providing accurate data support for revealing the reliability evolution mechanism of wide-bandgap semiconductor devices such as gallium nitride (GaN) and for system-level application evaluation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the circuit system structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the in-situ multi-parameter characterization circuit for the full dynamic characteristics of the power device of the present invention;

[0023] Figure 3 This is a key waveform of a multi-parameter in-situ characterization circuit for full dynamic characteristics under off-state drain bias stress according to Embodiment 1 of the present invention;

[0024] Figure 4 This is a key waveform of a multi-parameter in-situ characterization circuit for full dynamic characteristics under continuous switching stress according to Embodiment 2 of the present invention. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings.

[0026] like Figure 1 As shown, the circuit of this invention includes a high-voltage source circuit ①, a stress control module ②, a conduction characteristic network ③, a threshold voltage test module ④, a device under test (DUT) ⑤, and a control signal generation module ⑥. The high-voltage source circuit ① provides a stable off-state drain bias stress to the DUT, simulating a high-voltage operating environment. The stress control module ② is connected between the high-voltage source circuit ① and the conduction characteristic network ③ to precisely control the duration of stress application. The conduction characteristic network ③ is connected to the main power loop to characterize the dynamic on-resistance and transient switching characteristics in situ during device turn-on and turn-off transients. The threshold voltage test module ④ is connected between the gate and drain of the DUT to extract the dynamic threshold voltage VTH in situ during stress release transients. The control signal generation module ⑥ is connected to the PWM input of the isolation driver in each module to generate drive signals for the control circuit's operating timing, precisely controlling the seamless switching of the circuit between different test stages.

[0027] High-voltage source circuit ① consists of DC power supply V bus and filter capacitor C1. Wherein, DC power supply V... bus The positive terminal is connected to the input terminal of stress control module ②, and the negative terminal is connected to the source of device under test ⑤ and connected to common ground (GND); filter capacitor C1 is connected in parallel to DC power supply V. bus At both ends, it is used to stabilize the bus voltage and absorb transient stray charges from the switch.

[0028] The stress control module ② includes a bridge arm switching structure consisting of bidirectional power switches S1, S3, and S2, as well as isolation drivers D_S1, D_S2, and D_S3. The control terminal of S1 is connected to the output terminal of isolation driver D_S1, the control terminal of S2 is connected to the output terminal of isolation driver D_S2, and the control terminal of S3 is connected to the output terminal of isolation driver D_S3. The input terminal of S1 is connected to a DC high-voltage source V. bus At the output terminal, S1 and S3 are connected in series in the main power path, and S2 is connected between the output terminal of S3 and the common ground; by controlling the conduction and cutoff of power switches S1, S3 and S2, nanosecond-level cutoff and start-up of the high-voltage circuit can be achieved, and current can be prevented from flowing back into the high-voltage source during the test phase.

[0029] The conduction characteristic network ③ includes a load resistor R1 and a load inductor L1 connected in series, and a diode D1 connected in parallel across the load. The load resistor R1 is used to adjust the test current, and the load inductor L1 is used to simulate the inductive load effect. Furthermore, the conduction characteristic network ③ also integrates a dynamic voltage drop monitoring unit, which includes a DC power supply V. in2 The components include a current-limiting resistor R2, a Schottky diode D4, a filter capacitor C2, and a Zener diode D5. The anode of the Schottky diode D4 is connected to the drain of the device under test, and the cathode is connected to the DC power supply V through the current-limiting resistor R2. in2 It is used to clamp the test node voltage during device turn-off, thereby improving the test accuracy of dynamic voltage drop.

[0030] Threshold voltage test module ④ includes test power supply V in1 The system includes a test control switch S5, a constant current source I1, a drive isolation switch S4, isolation drivers D_S4, D_S5, and D_DUT, and a feedback diode branch. The first terminal of the test control switch S5 is connected to the test power supply V. in1 The second terminal is connected to the input terminal of the constant current source I1; the output terminal of the constant current source I1 is connected to the anode of isolation diodes D2 and D3 respectively; isolation diodes D2 and D3 are high-voltage, fast-recovery diodes, with their cathodes pointing towards the drain and gate of the device under test; during the stress application phase, D2 is in reverse cutoff state to shield the high voltage from impacting the test circuit, and D3 is used to prevent the drive output current from being shunted by the test branch; during the test phase, D2 and D3 are synchronously turned on to construct an adaptive feedback loop.

[0031] The following two specific embodiments illustrate in detail the testing method for in-situ multi-parameter characterization circuits of power devices' full dynamic characteristics. By extracting dynamic on-resistance, dynamic threshold voltage, and transient switching characteristics in-situ and in real-time within a single test platform, this method overcomes the data distortion problems caused by the single characterization dimension and test blind spots in existing solutions, providing data support for the reliability of power devices.

[0032] Example 1:

[0033] This example demonstrates in-situ characterization of multiple parameters of a device under off-state drain bias stress.

[0034] Multi-parameter in-situ characterization circuit for the full dynamic characteristics of power devices under off-state drain bias stress, such as Figure 2 As shown. The load resistor R1 in the conduction characteristic network ③ can be unconnected. Multi-parameter in-situ characterization of the device under off-state drain bias stress is performed based on the dual-pulse test (DPT) mode. In this mode, the fully dynamic multi-parameter in-situ characterization circuit operates based on the following six main control signals: the gate signal V of the stress-controlled half-bridge high-side switch S1. GS,S1 The gate signal V of the stress-controlled half-bridge low-side switch S2 GS,S2 The gate signal V of the power circuit isolation switch S3 GS,S3 The gate signal V of the drive circuit control switch S4 GS,S4 Test the gate signal V of control switch S5 GS,S5 and the gate signal V of the device under test GS,DUT Key waveforms of the test circuit are as follows: Figure 3 As shown.

[0035] Specifically, before time t0, the stress-controlled half-bridge high-side switch S1, the test control switch S5, and the device under test are all turned off; the stress-controlled half-bridge low-side switch S2 and the power circuit isolation switch S3 are turned on to eliminate the pre-stress brought to the device under test by the continuous connection of the high-voltage source circuit ①.

[0036] After a dead time period, at time t1, the high-side switch S1 of the stress-controlled half-bridge is turned on, and the low-side switch S2 is turned off, entering the off-state drain bias stress application stage, as follows: Figure 3 The t1-t2 stage is shown in the diagram. During this stage, the cathode potential of diode D2 is much higher than that of the anode, and it is in a reverse cutoff state, effectively shielding the high-voltage power circuit from the impact on the low-voltage test circuit. The magnitude of the off-state drain bias stress can be controlled by adjusting the voltage amplitude of the high-voltage source circuit. The duration of the off-state drain bias stress can be controlled by adjusting the time length of the t1-t2 stage.

[0037] During the time intervals t2-t5, the device under test (DUT) operates in dual-pulse test mode. In this phase, the drive circuit control switch S4 remains on, and a dual-pulse waveform is supplied to the gate of the DUT via the signal control module. The first pulse (t2-t3) is used to establish the dual-pulse test reference current; its pulse width is adjustable, and its falling edge can be used to evaluate the device's transient turn-off characteristics. The rising edge of the second pulse (t4-t5) can be used to evaluate the device's transient turn-on characteristics. During its turn-on phase, the on-state voltage drop can be accurately extracted based on the dynamic voltage drop monitoring unit, combined with the DUT's drain-source current I... DS,DUTThis method can quickly and accurately evaluate the dynamic on-resistance of a device. The specific calculation process is as follows:

[0038]

[0039] Among them, V F To quickly restore the turn-on voltage of Schottky diode D4.

[0040] At time t5, the dynamic on-resistance and transient switching characteristics of the device are tested. The high-side switch S1 of the stress-controlled half-bridge is turned off. After a dead time, at time t6, the low-side switch S2 is turned on, so that the voltage stress across the device under test is completely released.

[0041] At time t7, the power circuit isolation switch S3 is opened, and then at time t8, the drive circuit control switch S4 is opened, ensuring that the test circuit is completely decoupled from the power circuit and the gate drive circuit in the subsequent dynamic threshold voltage test phase, thus avoiding non-ideal leakage interference.

[0042] At time t9, test control switch S5 is turned on, and constant current source I1 injects milliampere-level current into the device. The injected current charges the gate-source capacitance of the device under test until the gate voltage V of the device under test is reached. GS,DUT When the current rises to a level where the drain and source can stably pass through the constant current source I1, the gate voltage of the device under test will automatically lock near its transient threshold voltage. The dynamic threshold voltage can be directly read out by acquiring the waveforms at both ends of the gate and source using an oscilloscope or a high-speed ADC.

[0043] t 10 At that moment, a single test cycle terminates.

[0044] Example 2:

[0045] This example demonstrates the in-situ characterization of multiple parameters of power devices under continuous switching stress.

[0046] Multi-parameter in-situ characterization circuit for the full dynamic characteristics of power devices under continuous switching stress, such as Figure 2 As shown. The load resistor R1 in the conduction characteristic network ③ has its value set according to the required operating current of the device under test. In this mode, the fully dynamic multi-parameter in-situ characterization circuit operates based on the following six main control signals: the gate signal V of the stress-controlled half-bridge high-side switch S1. GS,S1 The gate signal V of the stress-controlled half-bridge low-side switch S2 GS,S2 The gate signal V of the power circuit isolation switch S3 GS,S3 The gate signal V of the drive circuit control switch S4 GS,S4 Test the gate signal V of control switch S5 GS,S5 and the gate signal V of the device under test GS,DUT Key waveforms of the test circuit are as follows: Figure 4 As shown.

[0047] Compared to Example 1, during the stress application stage, the gate signal V of the pulse signal with a fixed frequency and duty cycle is provided to the device under test by the control signal generation module ⑥. GS,DUT Subsequently, during the conduction process of the last cycle of the device under test (e.g. Figure 4 During the t2-t3 phase, based on the dynamic voltage drop monitoring unit, the on-state voltage drop of the device is accurately extracted, combined with the current I on the load inductor L1 under test. L It can quickly and accurately evaluate the dynamic on-resistance of a device.

[0048] The dynamic threshold testing method is the same as in Specific Implementation Example 1, and will not be repeated here.

Claims

1. A multi-parameter in-situ characterization circuit for the full dynamic characteristics of a power device, characterized in that, It includes a high-voltage source circuit, a stress control module, a conduction characteristic network, a threshold voltage testing module, a device under test (DUT), and a control signal generation module; the high-voltage source circuit is connected to the input terminal of the stress control module and is used to provide a bias voltage. The stress control module is connected to the drain of the device under test and is used to control the time of stress application. The conduction characteristic network is connected to the main power loop to characterize dynamic on-resistance and transient switching characteristics; the threshold voltage test module is connected between the gate and drain of the device under test to extract the dynamic threshold voltage in situ; the control signal generation module is connected to the PWM input terminal of the isolation driver in each module to generate drive signals for the control circuit operating timing. The high-voltage source circuit includes a DC high-voltage source V. bus The filter capacitor C1 is connected in parallel with the DC high voltage source V. bus At the output terminal, the filter capacitor C1 is used to provide a stable off-state drain bias stress for the device under test, simulating the high-voltage operating environment of an actual power converter; The stress control module includes a bridge arm switching structure composed of bidirectional power switches S1, S3, and power switch S2, as well as isolation drivers D_S1, D_S2, and D_S3; wherein, the control terminal of S1 is connected to the output terminal of isolation driver D_S1, the control terminal of S2 is connected to the output terminal of isolation driver D_S2, and the control terminal of S3 is connected to the output terminal of isolation driver D_S3; the input terminal of S1 is connected to a DC high-voltage source V. bus At the output terminal, S1 and S3 are connected in series in the main power path, and S2 is connected between the output terminal of S3 and the common ground; by controlling the conduction and cutoff of switches S1, S3 and S2, nanosecond-level cutoff and start-up of the high voltage circuit can be achieved, and current is prevented from flowing back into the high voltage source during the test phase. The conductive characteristic network includes a load circuit, which consists of a load resistor R1 and a load inductor L1 connected in series, and a diode D1 connected in parallel across the load circuit. The cathode of the diode D1 is connected to the load resistor R1, and the anode of the diode D1 is connected to the load inductor L1. The load resistor R1 is used to adjust the test current and is connected to the connection point of switches S1 and S3. The load inductor L1 is used to simulate the inductive load effect. The conductive characteristic network also integrates a dynamic voltage drop monitoring unit; the dynamic voltage drop monitoring unit includes a DC power supply V. in2 The components include a current-limiting resistor R2, a Schottky diode D4, a filter capacitor C2, and a Zener diode D5. The cathode of the Schottky diode D4 is connected to the drain of the device under test and the anode of the diode D1, and the anode of the Schottky diode D4 is connected to the DC power supply V through the current-limiting resistor R2. in2 The positive terminal is used to clamp the test node voltage during device turn-off, improving the test accuracy of dynamic voltage drop; the filter capacitor C2 and the Zener diode D5 are connected in parallel, and the cathode of the Zener diode D5 is connected to the anode of the Schottky diode D4. The cathode of the Zener diode D5, the source of the device under test, and V in2 The negative terminal is connected to the public ground; The threshold voltage test module includes a test power supply V. in1 The system comprises a test control switch S5, a constant current source I1, a drive isolation switch S4, isolation drivers D_S4, D_S5, and D_DUT, and a feedback diode branch. The feedback diode branch includes an isolation diode D2 connected in series between the output of the constant current source I1 and the drain of the device under test (DUT), and a feedback diode D3 connected between the output of the constant current source I1 and the drive isolation switch S4. The cathode of isolation diode D2 is connected to the anode of diode D1. The cathode of feedback diode D3 and the output of drive isolation switch S4 are connected to the gate of the DUT. The input of drive isolation switch S4 is connected to the output of isolation driver D_DUT, and the control terminal of drive isolation switch S4 is connected to the output of isolation driver D_S4. The control terminal of test control switch S5 is connected to the output of isolation driver D_S5, and the input terminal of test control switch S5 is connected to the test power supply V. in1 The output of the test control switch S5 is connected to the input of the constant current source I1.

2. The in-situ multi-parameter characterization circuit for the full dynamic characteristics of a power device according to claim 1, characterized in that, The isolation diode D2 and feedback diode D3 are high-voltage, fast-recovery diodes. During the stress application phase, the isolation diode D2 is in a reverse cutoff state to shield the high voltage from impacting the test circuit, and the feedback diode D3 is used to prevent the drive output current from being shunted by the test branch. During the test phase, the isolation diode D2 and feedback diode D3 are synchronously turned on to construct an adaptive feedback loop.

3. The in-situ multi-parameter characterization circuit for the full dynamic characteristics of a power device according to claim 1, characterized in that, The control signal generation module includes a function signal generator and a first logic gate circuit, a second logic gate circuit, and a third logic gate circuit connected thereto; the first logic gate circuit outputs complementary drive signals S1 and S2; the second logic gate circuit outputs in-phase drive signals S3 and S4, which are opposite to the drive signal S5 output by the third logic gate circuit, and all signals are provided with a certain time delay.

4. A test method for a multi-parameter in-situ characterization circuit of the full dynamic characteristics of a power device, used for the circuit as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Stress preset stage: The stress control module controls S1 to turn on and S2 to turn off, so that the device under test is subjected to off-state drain bias stress for a set time. Switching characteristics and dynamic on-resistance testing phase: Keep S1 and S4 on, drive the device under test to work in switching mode through the control signal generation module; use the dynamic voltage drop monitoring unit to collect the voltage drop waveform across the drain and source, and combine the drain and source current to characterize the dynamic on-resistance and switching characteristics. Dynamic threshold voltage test phase: S1 is turned off and S2 is turned on, then S3 and S4 are turned off and S5 is turned on; constant current source I1 constructs a feedback loop through D3 and D2 to lock the gate voltage of the device under test at the dynamic threshold voltage and sample it.

5. The test method for a multi-parameter in-situ characterization circuit of the full dynamic characteristics of a power device according to claim 4, characterized in that, The test method uses a control signal generator to provide multi-pulse signals to make the device under test operate in continuous switching mode, thereby achieving in-situ evaluation of multiple parameters of the device after continuous switching stress.

6. The test method for a multi-parameter in-situ characterization circuit of the full dynamic characteristics of a power device according to claim 4, characterized in that, The test method obtains the evolution law of the dynamic characteristics of power devices affected by voltage, time, frequency and temperature by adjusting the voltage amplitude, stress time, switching frequency and ambient temperature of the high voltage source circuit.

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