Test circuit and chip

Abstract

The embodiment of the invention provides a test circuit and a chip. The test circuit can comprise a power module, and a power device comprises a drain electrode, a grid electrode and a source electrode; the control module is connected with the power module and is used for disconnecting the drain electrode and the source electrode when the high-temperature gate bias test is carried out on the power device, and carrying out bias voltage test on the gate electrode according to the obtained input power supply; the protection module is respectively connected with the control module and the power device and is used for judging whether the input power supply is greater than a preset voltage value and disconnecting the grid if the input power supply is greater than the preset voltage value; the input power supply voltage is monitored in real time through the protection module, the grid connection is cut off immediately once the voltage is detected to exceed a preset value, the risk of high voltage mistaken access is blocked from the hardware level, the power device is effectively prevented from being burnt out due to mistaken voltage during HTGB test, the stability of the test process is guaranteed, and it is ensured that the test is carried out according to a plan.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a test circuit and chip. Background Technology

[0002] With the development of technology, the demand for power device testing is increasing. In the process of conducting HTGB and HTRB tests on power devices, HTRB tests require high voltage, while HTGB test voltage is limited to the range of 20~30V. However, the current test switching process lacks effective protection or differentiation mechanisms, which can easily lead to operational errors such as incorrect connection of high voltage, resulting in the burnout of HTGB devices and ultimately affecting the overall test progress. Summary of the Invention

[0003] In view of the above problems, embodiments of the present invention are proposed to provide a test circuit and chip that overcomes or at least partially solves the above problems.

[0004] In a first aspect, embodiments of the present invention provide a test circuit, comprising: A power module, wherein the power device includes a drain, a gate, and a source; The control module, connected to the power module, is used to disconnect the drain and source when performing a high-temperature gate bias test on the power device, and to perform a bias test on the gate based on the acquired input power supply. A protection module, connected to both the control module and the power device, is used to determine whether the input power supply is greater than a preset voltage value. If the input power supply is greater than the preset voltage value, the gate is disconnected.

[0005] Optionally, the control module is further configured to disconnect the gate of the power module and perform a reverse bias test on the drain and source based on the input power supply when performing a high-temperature reverse bias test on the power device.

[0006] Optionally, the control module includes: A first control unit, comprising a first input terminal and a first output terminal, wherein the first input terminal is connected to a power supply and the first output terminal is connected to the drain of the power module, wherein the first control unit is used to short-circuit the first input terminal and the first output terminal and transmit the input power to the drain when performing a high-temperature reverse bias test on the power device.

[0007] Optionally, the control module further includes: The second control unit includes a second input terminal and a second output terminal. The second input terminal is connected to the power supply, and the second output terminal is connected to the source of the power module. The second control unit is used to short-circuit the second input terminal and the second output terminal when performing a high-temperature reverse bias test on the power device, and to transmit the input power to the source.

[0008] Optionally, the control module further includes: The third control unit includes a third input terminal and a third output terminal. The third input terminal is connected to the power supply, and the third output terminal is connected to the gate of the power module. The third control unit is used to disconnect the third input terminal and the third output terminal when performing a high-temperature reverse bias test on the power device.

[0009] Optionally, the third control unit is further configured to short-circuit the third input terminal and the third output terminal to transmit the input power to the gate when performing a high-temperature gate bias test on the power device.

[0010] Optionally, the test circuit further includes: A leakage current protection module, connected to the control module, is used to detect whether a leakage current phenomenon occurs in the control module. If a leakage current phenomenon occurs in the control module, the power supply to the control module is stopped.

[0011] Optionally, the test circuit further includes: An overcurrent protection module, connected to the control module, is used to detect whether the input current is greater than a preset current value. If the input current value is greater than the preset current value, the power supply to the control module is stopped.

[0012] Optionally, the protection module is a low-voltage TVS tube.

[0013] Secondly, embodiments of the present invention provide a chip, the electronic device including the test circuit as described above.

[0014] The embodiments of the present invention have the following advantages: This invention discloses a test circuit and chip. The test circuit may include a power module, and the power device includes a drain, a gate, and a source. A control module, connected to the power module, is used to disconnect the drain and source when performing a high-temperature gate bias test on the power device, and to perform a bias voltage test on the gate based on the acquired input power supply. A protection module, connected to both the control module and the power device, is used to determine whether the input power supply is greater than a preset voltage value. If the input power supply is greater than the preset voltage value, the gate is disconnected. During the HTGB test, the control module first disconnects the drain and source of the power device, and then performs a bias voltage test on the gate based on the input power supply, thus clarifying the action logic of the test step. At the same time, the protection module monitors the input power supply voltage in real time. Once the voltage is detected to exceed the preset value, the gate connection is immediately disconnected, thus blocking the risk of high voltage misconnection at the hardware level. This effectively avoids the power device being burned out due to incorrect voltage during the HTGB test, ensuring the stability of the test process and ensuring that the test proceeds as planned. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a structural block diagram of a test circuit provided in an embodiment of the present invention; Figure 2 This is a structural block diagram of another test circuit provided in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0019] One of the core concepts of this invention is the provision of a test circuit. This test circuit may include a power module, with the power device comprising a drain, a gate, and a source; a control module connected to the power module, used to disconnect the drain and source when performing a high-temperature gate bias test on the power device, and to perform a bias voltage test on the gate based on the acquired input power supply; and a protection module connected to both the control module and the power device, used to determine whether the input power supply is greater than a preset voltage value, and to disconnect the gate if the input power supply is greater than the preset voltage value. During HTGB testing, the control module first disconnects the drain and source of the power device, and then performs a bias voltage test on the gate based on the input power supply, thus clarifying the action logic of the test step. At the same time, the protection module monitors the input power supply voltage in real time, and once the voltage is detected to exceed the preset value, it immediately disconnects the gate connection, blocking the risk of high voltage misconnection from the hardware level, effectively preventing the HTGB device from being burned out due to incorrect voltage application, ensuring the stability of the test process, and ensuring that the test proceeds as planned.

[0020] Figure 1 This is a structural block diagram of a test circuit provided in an embodiment of the present invention. The circuit may include: Power module 101, the power device includes drain, gate and source; In this embodiment of the invention, the power module 101 is the core unit in the entire test circuit used to carry the power device under test. It has three key electrodes, namely the drain, gate and source. These three electrodes are important interfaces for the power device to transfer signals and energy with external circuits. They are also the direct points of application for the application and acquisition of various electrical signals during the test. The drain and source are usually used to form the main current path, while the gate controls the conduction and turn-off states of the power device by applying a bias voltage. Together, they constitute the basic structure for the power device to realize its electrical functions, providing a hardware connection object and action carrier for the subsequent test operations of the control module and protection module.

[0021] The control module 102, connected to the power module, is used to disconnect the drain and source when performing high-temperature gate bias test on the power device, and to perform gate bias test based on the acquired input power supply. In this embodiment of the invention, the control module 102 is the control core of the test circuit and is connected to the power module 101. It can precisely control the working state of the power device 101. When a high-temperature gate bias test is required on the power device, the control module 102 will first disconnect the connection between the drain and source of the power device. By cutting off the path between these two electrodes, it ensures that no additional current or voltage interference is introduced between the drain and source during the gate bias test, creating an independent and stable environment for the gate test. After disconnecting the drain and source, the control module 102 can obtain the externally input power signal. According to the specific requirements of the high-temperature gate bias test, the input power is processed and applied to the gate of the power device, thereby realizing the bias performance test of the gate under high temperature environment. The entire process ensures the accuracy and specificity of the test through orderly action control.

[0022] The protection module 103 is connected to the control module and the power device respectively. It is used to determine whether the input power supply is greater than the preset voltage value. If the input power supply is greater than the preset voltage value, the gate is disconnected.

[0023] In this embodiment of the invention, the protection module 103 plays a crucial role in safety protection within the circuit. It is connected to both the control module 102 and the power module 101, enabling it to monitor the voltage status during the testing process in real time and take corresponding protective actions. Its core function is to continuously assess the voltage value of the input power supply. Internally, a voltage threshold adapted to the high-temperature gate bias test is preset. During the test, the protection module 103 continuously compares the actual voltage of the input power supply with the preset voltage value. Once it detects that the voltage of the input power supply is greater than the preset voltage value, it indicates that a voltage misconnection may have occurred, such as connecting a high voltage suitable for other tests to the high-temperature gate bias test circuit. In this case, the protection module 103 will immediately take action to disconnect the connection with the gate of the power device, thereby preventing excessively high voltage from being applied to the gate and avoiding damage to the power device due to voltage errors. This effectively ensures the safety and reliability of the test and provides a critical safety barrier for the testing process.

[0024] In one example, during the initial High Temperature Reverse Bias (HTRB) test, an external high-voltage power supply is input. The protection module monitors this voltage in real time and detects that it exceeds a preset threshold. Since the HTGB test mode has not yet been entered, the control module does not trigger the drain-source disconnection operation. The high voltage is applied to the corresponding electrode of the power device through the adapter path, completing the HTRB test. When the test needs to switch to HTGB mode, the operator initiates the switching command. The control module responds immediately, first disconnecting the connection between the drain and source of the power device to isolate potential interference from the main current path, and then acquiring the externally input test power supply. Simultaneously, the protection module processes this input power supply... The system monitors the voltage. If, due to operational error, the high voltage used for HTRB testing is mistakenly connected, the protection module will quickly detect that the voltage exceeds the preset safety threshold and immediately trigger the protection mechanism to disconnect the gate connection, preventing the high voltage from impacting the gate and causing the device to burn out. If the input power supply is the compliant 25V voltage required for HTRB testing, the protection module determines that the voltage is within the safe range and does not trigger the disconnection action. The control module then processes the compliant voltage and applies it stably to the gate of the power device to complete the gate bias test in a high-temperature environment. The entire switching and testing process is controlled by the process control module and protected by the real-time protection module, achieving safe and accurate test connection.

[0025] This invention discloses a test circuit. During HTGB testing, the control module first disconnects the drain and source of the power device, and then performs a bias voltage test on the gate based on the input power supply, thus clarifying the action logic of the test step. At the same time, the protection module monitors the input power supply voltage in real time. Once the voltage exceeds the preset value, the gate connection is immediately disconnected, thus blocking the risk of high voltage misconnection from the hardware level. This effectively avoids the power device being burned out due to incorrect voltage during HTGB testing, ensuring the stability of the test process and ensuring that the test proceeds as planned.

[0026] In one embodiment of the present invention, the control module is further configured to disconnect the gate of the power module and perform reverse bias voltage test on the drain and source according to the input power supply when performing high-temperature reverse bias test on the power device.

[0027] In this embodiment of the invention, the control module 102 serves as the core control unit of the test circuit. When performing high-temperature reverse bias testing on power devices, it can initiate a targeted workflow based on the test type switching command. First, the control module precisely executes a gate disconnection operation, cutting off the circuit connection with the power module gate through internal switch control logic, leaving the gate in a floating state. This prevents the gate from being interfered with by additional voltage signals during the high-temperature reverse bias test, and also prevents abnormal gate potential from affecting the reverse bias test effect between the drain and source. After completing the gate disconnection, the control module can receive external inputs adapted to the high-temperature reverse bias test. The high-voltage power supply signal for the reverse bias test, after being processed by the internal circuitry for voltage regulation and current limiting, is precisely applied between the drain and source of the power device. The voltage polarity is strictly guaranteed to meet the reverse bias test requirements, allowing the power device to continuously withstand the specified reverse bias stress under high-temperature conditions. This enables the testing and evaluation of the electrical performance and reliability of the power device under high-temperature reverse bias conditions. Throughout the process, the control module maintains real-time monitoring of the circuit status, ensuring a stable gate disconnection state and accurate and continuous reverse bias output between the drain and source, providing stable control support for the successful implementation of the high-temperature reverse bias test.

[0028] Suppose that a power device needs to be switched to a high-temperature reverse bias test after completing the HTGB test. The entire process is carried out in an orderly manner under the guidance of the control module. After the HTGB test is completed, the operator issues a high-temperature reverse bias test start command. The control module responds immediately and switches its working mode. First, it quickly disconnects the connection path with the gate of the power device, so that the gate no longer receives any bias voltage signal, completely isolating the gate from interference with subsequent tests. Then, the control module connects to the external high-voltage power supply for high-temperature reverse bias test. After adaptation processing by the internal circuit, a stable high-voltage reverse bias is applied between the drain and source of the power device. At the same time, the control module monitors the voltage value of the drain and source and the loop current in real time to ensure that the test parameters meet the standard requirements. Under the continuous action of the high-temperature environment, the power device maintains a stable working state under reverse bias. The control module continuously maintains the state of gate disconnection and stable output of reverse bias voltage between the drain and source until the high-temperature reverse bias test of the preset duration is completed. The entire process does not require additional manual intervention, realizing the automation and precise control of test mode switching and test process.

[0029] In high-temperature reverse bias testing, the control module employs precise control logic—first disconnecting the gate and then applying the reverse bias voltage—effectively ensuring the professionalism and reliability of the test. This gate-first disconnection operation prevents interference from the gate signal to the drain and source reverse bias voltage tests, ensuring the purity of the test environment. Simultaneously, through adaptive processing and precise application of the input power supply, the stability and accuracy of the reverse bias voltage between the drain and source are guaranteed, meeting the stringent requirements of high-temperature reverse bias testing. This targeted control method not only enables smooth switching between HTGB and HTRB high-temperature reverse bias testing without requiring additional independent test circuitry, but also enhances the automation of the testing process, reduces human error, and, combined with the safety protection of the protection module, further reduces the risk of device damage during testing, ensuring the orderly progress of different types of tests and significantly improving the overall efficiency and reliability of power device testing.

[0030] In one embodiment of the present invention, the control module includes: a first control unit, the first control unit including a first input terminal and a first output terminal, the first input terminal being connected to a power supply, and the first output terminal being connected to the drain of the power module. The first control unit is used to short-circuit the first input terminal and the first output terminal and transmit input power to the drain when performing a high-temperature reverse bias test on the power device.

[0031] In embodiments of the present invention, such as Figure 2 The diagram shows a structural block diagram of another test circuit provided by an embodiment of the present invention. The control module 102 may include a first control unit P1. The first control unit P1 may include a first input terminal and a first output terminal. The first input terminal is connected to a power supply, and the first output terminal is connected to the drain of the power module. The first control unit is used to short-circuit the first input terminal and the first output terminal and transmit the input power to the drain when performing a high-temperature reverse bias test on the power device.

[0032] The first control unit P1, as a key component in the control module 102 responsible for drain power transmission, operates closely around the requirements of high-temperature reverse bias testing. Its core function is to achieve efficient power transmission through precise port control. When the high-temperature reverse bias test is initiated, the first control unit P1 first confirms its connection status: the first input terminal maintains a stable connection with the external input power supply, which is a high-voltage power supply specifically designed for high-temperature reverse bias testing, and its voltage value meets the reverse bias requirements of the test standard; the first output terminal always forms a reliable circuit connection with the drain of the power module, ensuring a smooth signal transmission path. Upon receiving the test start command from the control module, the switching mechanism inside the first control unit P1 quickly activates, directly short-circuiting the first input terminal and the first output terminal. This short-circuit operation is not a simple... Instead of a continuous circuit, the establishment of a low-impedance path eliminates interference factors such as resistance loss and contact impedance that may exist during power transmission, allowing the input power to be transmitted from the input end to the output end with almost no attenuation. Subsequently, the high-voltage power transmitted through the short-circuit path is precisely applied to the drain of the power device through the first output end. At the same time, with the control module's gate disconnection processing and source circuit configuration, a stable reverse bias environment is finally established between the drain and source, meeting the test requirements of the power device to withstand reverse bias stress under high temperature conditions. Throughout the test, the first control unit P1 continuously maintains the short-circuit state between the input and output ends, monitors the stability of the path in real time, and ensures that the drain voltage always meets the test parameter requirements until the end of the test cycle, at which point it responds to the command to disconnect the short circuit and restore the initial state.

[0033] Taking the high-temperature reverse bias test of a power device as an example, when the test system switches to this mode, the first control unit P1 enters the working state. Its first input terminal is connected to a 1000V high-voltage test power supply, and the first output terminal is firmly connected to the drain of the power module through a wire. After the test command is issued, the electromagnetic relay inside the first control unit P1 immediately engages, directly short-circuiting the circuit between the input terminal and the output terminal. The transmission path that might have caused a voltage drop due to line resistance is replaced by a low-impedance short-circuit path. The 1000V high-voltage power supply is transmitted from the input terminal to the output terminal without attenuation and is precisely applied to the drain of the power device. At this time, the control module has synchronously disconnected the gate connection, and the source terminal is grounded to form a loop. A stable 1000V reverse bias voltage is established between the drain and the source terminal. The power device continuously withstands this bias stress in the high-temperature chamber (such as a 150℃ environment). During the test, the short-circuit state of the first control unit P1 remained stable. Even if there were slight fluctuations in the input power supply, it could respond quickly through the low impedance characteristics of the short-circuit path, ensuring that the drain voltage remained stable at around 1000V until the end of the 48-hour test cycle, when the relay disconnected, the short-circuit state was released, and the test was completed.

[0034] The low impedance characteristic of the short-circuit path in this invention minimizes power loss and fluctuations during power transmission, ensuring that the drain receives a stable, accurate, and test-compliant high-voltage power supply. This provides a reliable guarantee for the effective application of reverse bias and avoids data distortion due to voltage instability. The control logic of this direct short circuit has a fast response speed and simple operation, which can quickly adapt to the start-up requirements of high-temperature reverse bias testing. Combined with the gate disconnection control of the control module, it further isolates interference from irrelevant signals, ensuring the purity of the test environment. At the same time, stable power transmission and precise port control reduce the risk of failure due to circuit complexity, improve the reliability and efficiency of the test process, and provide key support for the smooth conduct of high-temperature reverse bias testing of power devices.

[0035] In one embodiment of the present invention, the control module 102 may further include a second control unit P2, which includes a second input terminal and a second output terminal. The second input terminal is connected to a power supply, and the second output terminal is connected to the source of the power module. The second control unit is used to short-circuit the second input terminal and the second output terminal to transmit input power to the source when performing a high-temperature reverse bias test on the power device.

[0036] In this embodiment of the invention, when the power device enters the high-temperature reverse bias test mode, the second control unit P2 first confirms its connection status. The second input terminal maintains a reliable connection with the external input power supply. This power supply works in conjunction with the power supply connected to the first control unit to jointly meet the requirement of forming a reverse bias voltage between the drain and source. The second output terminal forms a stable circuit connection with the source of the power module, ensuring that the power signal can be transmitted to the source without obstruction. After receiving the test start command issued by the control module, the switching component inside the second control unit P2 quickly operates, directly short-circuiting the second input terminal and the second output terminal. This short-circuit operation effectively regulates the voltage by constructing a low-impedance path. By avoiding voltage loss or signal distortion caused by factors such as line resistance and poor contact during power transmission, the input power can be transmitted from the input terminal to the output terminal in a near-original state. Subsequently, the power transmitted through the short-circuit path is precisely applied to the source of the power device through the second output terminal. In conjunction with the high-voltage power transmitted from the first control unit to the drain, a reverse bias circuit that meets the test requirements is formed between the drain and the source. Throughout the high-temperature reverse bias test, the second control unit P2 maintains the short-circuit state between the input and output terminals, monitors the stability of the path in real time, and ensures the continuous stability of the source voltage until the test is completed and the short circuit is disconnected in response to the command, restoring the initial standby state.

[0037] Taking the high-temperature reverse bias test of a power device as an example, when the test system switches to this mode, the second control unit P2 starts working. Its second input terminal is connected to a power supply that matches the test requirements, and its second output terminal is tightly connected to the source of the power module through a dedicated wire. After the test command is issued, the solid-state relay inside the second control unit P2 immediately conducts, short-circuiting the second input terminal and the second output terminal. The reference power supply is directly transmitted to the second output terminal through the low-impedance short-circuit path and is precisely applied to the source of the power device. At this time, the first control unit has transmitted 1000V high voltage to the drain, while the gate is in the open state. A stable 1000V reverse bias voltage is formed between the drain and the source. In a high-temperature environment (such as 125℃), the power device continuously withstands this reverse bias stress. The second control unit P2 always remains in the short-circuit state to ensure the stable output of the source reference voltage. Even if there are slight fluctuations in the external power supply, the short-circuit path can quickly cancel the interference and maintain the constant source voltage until the preset 24-hour test cycle ends. The solid-state relay is disconnected, the short-circuit state is released, the source no longer receives power signals, and the test process is successfully completed.

[0038] The low-impedance path formed by the short circuit in this invention minimizes power loss and interference during power transmission, ensuring a stable and accurate voltage signal at the source. This provides crucial support for the stable establishment of the reverse bias voltage between the drain and source, preventing deviations in the reverse bias parameters from the test standard due to source voltage fluctuations and ensuring the accuracy of the test data. This direct short-circuit control logic offers rapid response and simple operation, quickly adapting to the startup and operation requirements of high-temperature reverse bias testing. Working in conjunction with the first control unit, it forms a precise voltage control system for the drain and source, further enhancing the synergy and reliability of the test circuit. Simultaneously, stable power transmission reduces the risk of test interruptions due to circuit faults, minimizing the need for manual intervention and significantly improving the efficiency and stability of high-temperature reverse bias testing, providing a solid guarantee for the reliability assessment of power devices.

[0039] In one embodiment of the present invention, the control module 102 may further include a third control unit P3, which includes a third input terminal and a third output terminal. The third input terminal is connected to a power supply, and the third output terminal is connected to the gate of the power module. The third control unit is used to disconnect the third input terminal and the third output terminal when performing a high-temperature reverse bias test on the power device.

[0040] In this embodiment of the invention, the third control unit P3, as a key component in the control module 102 specifically responsible for gate circuit on / off control, has working logic that is deeply aligned with the core requirements of high-temperature reverse bias testing. Its core function is to ensure complete isolation between the gate and the power supply during the test through precise circuit breaking operations. When the power device enters the high-temperature reverse bias test mode, the third control unit P3 first clarifies its initial connection state: the third input terminal remains continuously connected to the external power supply, while the third output terminal forms a stable circuit connection with the gate of the power module, providing the hardware foundation for on / off control. Upon receiving the high-temperature reverse bias test start command from the control module, the switching mechanism inside the third control unit P3 quickly activates, completely disconnecting the circuit between the third input terminal and the third output terminal, thus achieving the circuit breaking state. This circuit breaking operation is not a simple... Instead of interrupting the signal, the circuit is physically isolated, completely cutting off any current or voltage transmission path between the gate and the external power supply, leaving the gate in a floating state. It neither receives any bias signal nor feeds back interference signals to other circuits. Throughout the high-temperature reverse bias test, the third control unit P3 maintains this open-circuit state, using an internal monitoring mechanism to confirm the insulation between the input and output terminals in real time. This ensures that the gate will not introduce additional voltage due to accidental conduction, avoiding interference with the reverse bias test between the drain and source. Only after the high-temperature reverse bias test ends and the control module issues a mode switching command will the third control unit P3 respond to the command, release the open-circuit state, and restore the circuit connection between the input and output terminals, preparing for the application of gate bias in subsequent test modes (such as HTGB test).

[0041] Taking the scenario of a power device switching from HTGB testing to high-temperature reverse bias testing as an example, the operation of the third control unit P3 is as follows: During the HTGB testing phase, the third control unit P3 is in the on state, with its third input terminal connected to a 25V gate bias power supply, and its third output terminal transmitting this bias voltage to the gate; when the test system switches to the high-temperature reverse bias testing mode, the control module sends a circuit-breaking command to P3, and the electromagnetic relay inside P3 immediately disconnects its contacts, completely separating the circuit between the third input terminal and the third output terminal. At this time, even if the third input terminal is still connected to the 25V power supply, due to the existence of the circuit-breaking state, the gate cannot receive any voltage signal and is in a completely floating state. At the same time, the first control unit and the second control unit transmit high voltage and reference voltage to the drain and source terminals respectively, forming a stable reverse bias voltage between them. In high-temperature environments (such as 150℃), the power devices continuously withstand reverse bias stress. During this period, the third control unit P3 ensures through internal monitoring that the relay contacts are not stuck, the circuit has no leakage current, and the gate remains floating until the high-temperature reverse bias test is completed. The control module then issues a recovery command, the relay contacts close, and the third input terminal and the third output terminal are reconnected, preparing for the next test.

[0042] The open-circuit state of this invention completely cuts off the connection between the gate and the external power supply, leaving the gate in a floating state. This fundamentally avoids interference from the gate bias signal on the reverse bias test between the drain and source, ensuring the purity of the test environment and guaranteeing the accuracy and stability of the reverse bias parameters. This precise open-circuit control responds quickly and is stable, reliably adapting to the startup and operation requirements of high-temperature reverse bias tests. It works in conjunction with the first and second control units to achieve targeted control of the gate, drain, and source, respectively, thus constructing a test circuit control system with clear division of labor and close cooperation.

[0043] In one embodiment of the present invention, the third control unit is further configured to short-circuit the third input terminal and the third output terminal to transmit input power to the gate when performing a high-temperature gate bias test on the power device.

[0044] In this embodiment of the invention, the third control unit P3, as the core component responsible for gate power transmission in the control module 102, plays a crucial role in providing a stable bias voltage to the gate during high-temperature gate bias testing. Its operation closely revolves around the testing requirements to achieve precise circuit control. When the power device enters the high-temperature gate bias test mode, the third control unit P3 first confirms its connection status: the third input terminal maintains a reliable connection with the external input power supply, which is a low-voltage power supply specifically for high-temperature gate bias testing, meeting the voltage requirements of the gate bias test; the third output terminal forms a stable circuit connection with the gate of the power module, ensuring that the power signal can be transmitted to the gate without obstruction. After receiving the test start command from the control module, the switching component inside the third control unit P3 quickly activates, directly short-circuiting the third input terminal and the third output terminal. This short circuit... By constructing a low-impedance path, the operation effectively eliminates voltage loss or fluctuations caused by factors such as line resistance and contact impedance during power transmission. This allows the low-voltage power supply to be transmitted from the input to the output with almost no attenuation. Subsequently, the low-voltage power supply transmitted through the short-circuit path is precisely applied to the gate of the power device through the third output. Simultaneously, the control module disconnects the drain and source, ensuring that the gate continuously receives a stable bias voltage under high-temperature conditions. This meets the stringent requirements of high-temperature gate bias testing for gate voltage. Throughout the entire test, the third control unit P3 maintains a short-circuit state between the input and output, and uses an internal monitoring mechanism to confirm the stability of the path in real time, ensuring the continuous stability of the gate bias voltage. It then responds to the command to disconnect the short circuit after the test cycle ends, restoring the initial standby state and preparing for subsequent test mode switching.

[0045] Upon receiving the HTGB test command, this invention short-circuits the third input terminal and the third output terminal to form a low-impedance transmission path, avoiding voltage attenuation caused by line resistance or poor contact. This ensures that the actual voltage received by the gate is highly consistent with the input power supply voltage, meeting the 20~30V voltage accuracy requirement of high-temperature gate bias test and guaranteeing the accuracy of test parameters.

[0046] In one embodiment of the present invention, the test circuit further includes: a leakage protection module connected to the control module, used to detect whether a leakage phenomenon occurs in the control module, and if a leakage phenomenon occurs in the control module, to stop supplying power to the control module.

[0047] In embodiments of the present invention, such as Figure 1 The test circuit may also include: a leakage current protection module IS, which is connected to the control module and is used to detect whether a leakage current phenomenon occurs in the control module. If a leakage current phenomenon occurs in the control module, the power supply to the control module is stopped.

[0048] First, a dual connection is established between the leakage current protection module (IS) and the control module. On one hand, the current distribution information inside the control module is acquired in real time through the signal acquisition line, including key parameters such as the input current, output current, and loop leakage current of each control unit. On the other hand, the power supply control line is connected to the power input terminal of the control module, enabling it to cut off the power supply to the control module. During the operation of the test circuit, regardless of whether it is in high-temperature reverse bias test or high-temperature grid bias test mode, the leakage current protection module (IS) is always active. Its internal current sensing element continuously monitors the current balance of the control module. Under normal circumstances, the input current and output current of the control module remain balanced, and the leakage current is within the safe threshold range. At this time, the leakage current protection module (IS) only performs data acquisition and status recording. The system records data without interfering with circuit operation. When leakage occurs inside the control module due to insulation aging, line damage, component failure, or other reasons, a difference appears between the input current and the output current. If the leakage current exceeds the preset safety threshold, the leakage protection module IS will immediately trigger the protection mechanism: First, the internal logic circuit quickly determines the authenticity of the leakage fault. After confirming the fault, it quickly issues a cut-off command through the power supply control line, driving the internal circuit breaker to disconnect the control module from the external power supply and stop supplying power to the control module. At the same time, the leakage protection module IS will issue a fault signal to prompt the operator to check for potential leakage hazards. Only after the fault is eliminated and manually reset will the leakage protection module IS restore the power supply path, allowing the control module to restart. The circuit can only operate again after the leakage fault is completely resolved.

[0049] In this embodiment of the invention, the leakage current protection module IS significantly improves the overall safety and reliability of the test circuit by real-time monitoring of the leakage current status of the control module and rapid power-off protection. Its continuous monitoring mechanism can promptly detect potential leakage current hazards caused by internal faults in the control module, avoiding abnormal circuit performance or device damage caused by the accumulation of leakage current. When leakage occurs, the rapid power cut-off action can block the leakage current circuit from the source, prevent the risk of electric shock caused by leakage, protect the personal safety of operators, and at the same time avoid the leakage current from interfering with or causing secondary damage to the power device test.

[0050] In one embodiment of the present invention, the test circuit further includes an overcurrent protection module F1, which is connected to the control module and is used to detect whether the input current is greater than a preset current value. If the input current value is greater than the preset current value, the power supply to the control module is stopped.

[0051] In this embodiment of the invention, the overcurrent protection module F1 is connected in series in the power input path of the control module. On the one hand, it can collect the total current signal flowing into the control module in real time. On the other hand, it can directly control the on / off of the power path through the internally integrated execution structure. After the test circuit is started, regardless of whether it is in the high temperature gate bias test or the high temperature reverse bias test mode, the overcurrent protection module F1 will first load the corresponding preset current threshold according to the current test type. The threshold is set based on the rated operating parameters of the control module and the power device. For example, in the high temperature gate bias test, since the gate only needs a low voltage power supply of 20~30V, the current is small, and the preset threshold may be set to 0.5A. In the high temperature reverse bias test, since the drain needs a high voltage power supply, the current is relatively large, and the threshold may be set to 3A, ensuring that the current under normal test conditions will not trigger the protection action.

[0052] During testing, the module's internal current sensing element continuously samples the input current with high precision and dynamically compares the real-time current value with a preset threshold. When the current is within a safe range, the module maintains its open circuit state, allowing the current to flow smoothly into the control module, ensuring the test proceeds as planned. If the input current surges due to a short circuit in the control module's internal components, unexpected conduction of power devices, or abnormal voltage boost from the external power supply, exceeding the preset threshold, the overcurrent protection module F1 immediately activates multi-level protection logic. First, it confirms the authenticity of the overcurrent state through its internal comparison circuit. Then, it triggers the execution structure to act rapidly within milliseconds, disconnecting the control module from the power supply and completely stopping power supply to the control module. This prevents excessive current from continuously flowing through the control module, power devices, and related circuits. Simultaneously, the module sends a fault signal to the main control system via its built-in alarm device or by alerting the operator of the overcurrent fault. After the operator has investigated and resolved the fault, the overcurrent protection module must be manually reset or remotely commanded to restore the open circuit before the control module can be reconnected to the power supply to continue testing.

[0053] The F1 overcurrent protection module significantly improves the safety and reliability of the test circuit by monitoring the input current in real time and quickly cutting off the power supply when the threshold is exceeded. Its design dynamically adapts to the preset current threshold according to different test modes, which not only ensures accurate compatibility during normal testing and avoids false triggers that affect the test progress, but also responds quickly when the current is abnormal, preventing excessive current from causing burnout or permanent damage to the control module, power devices and other circuit components, greatly reducing equipment maintenance costs and test interruption risks. At the same time, the overcurrent protection mechanism effectively prevents safety hazards such as circuit fires and insulation failures caused by current overload, providing an important safety barrier for operators.

[0054] In one embodiment of the present invention, the protection module is a low-voltage TVS tube.

[0055] In this embodiment of the invention, the low-voltage TVS diode, as the core protection module of the test circuit, plays a crucial role in protecting the gate from overvoltage during HTGB testing through precise circuit connections and characteristic design. One end of the low-voltage TVS diode is connected to the power output terminal of the control module, and the other end is grounded. Its operating voltage is strictly selected to be within the safe range for HTGB testing, typically slightly higher than the 20-30V rated bias voltage required for HTGB testing, ensuring that it does not affect circuit operation during normal testing. During testing, the low-voltage TVS diode does not operate during HTRB testing. At critical points during HTGB testing switching, the low-voltage TVS diode is in standby mode. When the input power supply is the compliant voltage (20-30V) required for HTGB testing, the TVS diode operates at... In the off state, which is equivalent to an open circuit, the TVS diode does not interfere with the circuit operation, allowing the bias voltage output by the control module to be smoothly transmitted to the gate, ensuring normal test performance. If, due to operational error, the high voltage used for HTRB testing is mistakenly connected, or if a momentary overvoltage pulse occurs in the input power supply, when the voltage exceeds the breakdown voltage (preset voltage value) of the low-voltage TVS diode, the TVS diode will quickly switch from the off state to the on state within nanoseconds, forming a low-impedance path to quickly discharge excess high-voltage energy through the ground terminal. At the same time, it clamps the voltage across the gate within the safety threshold, preventing high voltage from being directly applied to the gate. Once the overvoltage hazard is eliminated and the input voltage returns to the compliant range, the low-voltage TVS diode will automatically return to the off state, and the circuit will return to normal test mode, continuously protecting the gate safety without manual intervention.

[0056] This invention uses a low-voltage TVS diode as a protection module, which significantly improves the overvoltage protection response speed and reliability of the test circuit. Its nanosecond-level conduction response capability can quickly act in the instant of high voltage misconnection or instantaneous overvoltage, completely blocking the impact of high voltage on the gate in HTGB testing, effectively preventing power devices from burning out due to overvoltage, and ensuring that the test progress is not affected. The automatic recovery feature of the TVS diode allows the circuit to return to normal after the fault is cleared without manual reset, improving the continuity and efficiency of testing.

[0057] This invention discloses a test circuit. During HTGB testing, the control module first disconnects the drain and source of the power device, and then performs a bias voltage test on the gate based on the input power supply, thus clarifying the action logic of the test step. At the same time, the protection module monitors the input power supply voltage in real time. Once the voltage exceeds the preset value, the gate connection is immediately disconnected, thus blocking the risk of high voltage misconnection from the hardware level. This effectively avoids the power device being burned out due to incorrect voltage during HTGB testing, ensuring the stability of the test process and ensuring that the test proceeds as planned.

[0058] As the apparatus embodiment is basically similar to the method embodiment, it is described in a relatively simple manner. For relevant details, please refer to the description of the method embodiment.

[0059] This invention also provides a chip including the above-described test circuit, which will not be described again here to avoid repetition.

[0060] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0061] The above provides a detailed description of the test circuit and chip provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A test circuit, characterized in that, include: A power module, wherein the power device includes a drain, a gate, and a source; The control module, connected to the power module, is used to disconnect the drain and source when performing a high-temperature gate bias test on the power device, and to perform a bias test on the gate based on the acquired input power supply. A protection module, connected to both the control module and the power device, is used to determine whether the input power supply is greater than a preset voltage value. If the input power supply is greater than the preset voltage value, the gate is disconnected.

2. The test circuit according to claim 1, characterized in that, The control module is also used to disconnect the gate of the power module and perform reverse bias voltage test on the drain and source according to the input power supply when performing high temperature reverse bias test on the power device.

3. The test circuit according to claim 2, characterized in that, The control module includes: A first control unit, comprising a first input terminal and a first output terminal, wherein the first input terminal is connected to a power supply and the first output terminal is connected to the drain of the power module, wherein the first control unit is used to short-circuit the first input terminal and the first output terminal and transmit the input power to the drain when performing a high-temperature reverse bias test on the power device.

4. The test circuit according to claim 3, characterized in that, The control module further includes: The second control unit includes a second input terminal and a second output terminal. The second input terminal is connected to the power supply, and the second output terminal is connected to the source of the power module. The second control unit is used to short-circuit the second input terminal and the second output terminal when performing a high-temperature reverse bias test on the power device, and to transmit the input power to the source.

5. The test circuit according to claim 4, characterized in that, The control module further includes: The third control unit includes a third input terminal and a third output terminal. The third input terminal is connected to the power supply, and the third output terminal is connected to the gate of the power module. The third control unit is used to disconnect the third input terminal and the third output terminal when performing a high-temperature reverse bias test on the power device.

6. The test circuit according to claim 5, characterized in that, The third control unit is also used to short-circuit the third input terminal and the third output terminal when performing a high-temperature gate bias test on the power device, so as to transmit the input power to the gate.

7. The test circuit according to claim 1, characterized in that, The test circuit also includes: A leakage current protection module, connected to the control module, is used to detect whether a leakage current phenomenon occurs in the control module. If a leakage current phenomenon occurs in the control module, the power supply to the control module is stopped.

8. The test circuit according to claim 1, characterized in that, The test circuit also includes: An overcurrent protection module, connected to the control module, is used to detect whether the input current is greater than a preset current value. If the input current value is greater than the preset current value, the power supply to the control module is stopped.

9. The test circuit according to claim 1, characterized in that, The protection module is a low-voltage TVS diode.

10. A chip, characterized in that, The chip includes the test circuit as described in any one of claims 1-9.

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