Electrical protection device and method
By designing an electrical protection device, using the measurement sub-circuit, the threshold judgment sub-circuit and the protection output sub-circuit, the voltage and current values of the measured semiconductor are monitored and judged in real time, and the problem of lack of effective overvoltage and overcurrent protection in the prior art is solved, and efficient protection effect is achieved and testing accidents are avoided.
Patent Information
- Application Number
- CN202510021428.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-04-25
AI Technical Summary
The lack of effective overvoltage and overcurrent protection schemes in the prior art leads to frequent accidents such as pipe blowing during the dynamic parameter testing of the semiconductor under test, especially in high voltage and high current environments, where the transient response time requirements are extremely high.
An electrical protection device is designed, including a measuring sub-circuit, a threshold judging sub-circuit and a protection output sub-circuit. The measurement sub-circuit measures the voltage and current values of the measured semiconductor in real time. The threshold value judgment sub-circuit determines whether overvoltage and/or overcurrent occurs based on the preset voltage threshold, and sends a signal to the protection output sub-circuit. The protection output sub-circuit outputs the signal to turn off the measured semiconductor.
Real-time monitoring and extremely fast response in high-voltage and high-current environments are achieved, avoiding accidents such as tube blasting caused by overvoltage and/or overcurrent during dynamic parameter testing of the semiconductor under test, and ensuring the accuracy and safety of the test.
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Figure CN119891094A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of power electronics technology, and more specifically, to an electrical protection device and method. Background Art
[0002] The dynamic parameter test of the semiconductor under test faces many challenges. During the test, the test voltage will reach the kilovolt level, and the impact current will be around several hundred amperes. Overvoltage and overcurrent phenomena may damage the semiconductor under test, so electrical protection devices are needed to protect the device under test and the test equipment. The electrical protection device detects the voltage and current in the circuit. When the voltage or current value exceeds a certain specified range, the circuit will be cut off immediately to protect the circuit components and lines. This protection device is crucial in the dynamic parameter test of the semiconductor under test and can ensure the accuracy and safety of the test.
[0003] At present, the industry usually uses double pulse testing to simulate the switching process of the semiconductor under test in actual applications, thereby measuring the dynamic parameters of the semiconductor under test. At present, there is no mature overvoltage and overcurrent protection solution for the test system of the semiconductor under test, which also leads to frequent accidents of pipe explosion or even equipment explosion during the test process. The difficulty lies in not only realizing real-time monitoring of high voltage and high current (≥1kV / 100A), but also having extremely fast response speed when overvoltage and overcurrent occur. The transient response time of the protection device is extremely high, reaching the microsecond or even nanosecond level. Summary of the invention
[0004] In view of the defects of the prior art, the purpose of the present application is to provide an electrical protection device and method, which aims to solve the problem of accidents such as pipe explosion caused by overvoltage and overcurrent in the dynamic parameter testing process of the semiconductor under test in the prior art.
[0005] To achieve the above objectives, in a first aspect, the present application provides an electrical protection device, comprising:
[0006] The measuring subcircuit is used to measure the voltage value and current value of the semiconductor under test during the dynamic parameter test process, and send the first voltage value and the second voltage value to the threshold judgment subcircuit, the first voltage value is determined according to the voltage value, and the second voltage value is determined according to the current value;
[0007] The threshold judgment subcircuit is connected to the measurement subcircuit, and is used to judge the first voltage value, the second voltage value and the preset voltage threshold value, and when it is determined that an overvoltage and / or overcurrent phenomenon occurs, send a first signal used to indicate the occurrence of the overvoltage and / or overcurrent phenomenon to the protection output subcircuit;
[0008] The protection output subcircuit is used to output a second signal for shutting down the semiconductor under test according to the first signal, and send the second signal to the semiconductor under test to disconnect the semiconductor under test.
[0009] In some embodiments, the measurement subcircuit includes:
[0010] Voltage detection module and current detection module;
[0011] The voltage detection module includes a voltage-dividing resistor and a first operational amplifier. The voltage value at both ends of the semiconductor under test is input to the positive electrode of the first operational amplifier through the voltage-dividing resistor. The negative electrode of the first operational amplifier is connected to the output end of the first operational amplifier. The output end of the first operational amplifier is connected to the threshold judgment subcircuit.
[0012] The current detection module includes a sampling resistor and a second operational amplifier. The current information flowing through the semiconductor under test is input into the positive electrode of the second operational amplifier through the sampling resistor. The negative electrode of the second operational amplifier is connected to the output end of the second operational amplifier. The output end of the second operational amplifier is connected to the threshold judgment subcircuit.
[0013] In some embodiments, the threshold determination subcircuit includes:
[0014] A first digital-to-analog converter, a second digital-to-analog converter, third to sixth operational amplifiers, and a first logic device;
[0015] The output end of the first digital-to-analog converter is connected to the positive electrode of the third operational amplifier, the negative electrode of the third operational amplifier is connected to the output end of the third operational amplifier, the output end of the third operational amplifier is connected to the negative electrode of the fifth operational amplifier, the positive electrode of the fifth operational amplifier is connected to the measurement sub-circuit, the output end of the fifth operational amplifier is connected to the first input end of the first logic device, the output end of the second digital-to-analog converter is connected to the positive electrode of the fourth operational amplifier, the negative electrode of the fourth operational amplifier is connected to the output end of the fourth operational amplifier, the output end of the fourth operational amplifier is connected to the negative electrode of the sixth operational amplifier, the positive electrode of the sixth operational amplifier is connected to the measurement sub-circuit, the output end of the sixth operational amplifier is connected to the second input end of the first logic device, and the output end of the first logic device is connected to the protection sub-circuit.
[0016] In some embodiments, it also includes:
[0017] The controller is connected to the threshold judgment subcircuit and is used to set the voltage thresholds of the first digital-to-analog converter and the second digital-to-analog converter.
[0018] In some embodiments, the threshold determination subcircuit is further configured to:
[0019] When a first voltage value at the output terminal of the first operational amplifier is greater than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output terminal of the second operational amplifier is less than a voltage threshold of the second digital-to-analog converter, determining that an overvoltage phenomenon occurs;
[0020] When a first voltage value at the output terminal of the first operational amplifier is less than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output terminal of the second operational amplifier is greater than a voltage threshold of the second digital-to-analog converter, determining that an overcurrent phenomenon occurs;
[0021] When a first voltage value at the output end of the first operational amplifier is greater than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output end of the second operational amplifier is greater than a voltage threshold of the second digital-to-analog converter, it is determined that overvoltage and overcurrent phenomena occur.
[0022] In some embodiments, the first logic device is an OR gate.
[0023] In some embodiments, the protection output subcircuit includes:
[0024] A second logic device to a fourth logic device, a first switching device and a second switching device;
[0025] The input end of the second logic device is connected to the threshold judgment subcircuit, the output end of the second logic device is connected to the first input end of the fourth logic device, the second input end of the fourth logic device is grounded, the first input end of the third logic device is connected to the threshold judgment subcircuit, the second input end of the third logic device is grounded, the output end of the third logic device is connected to the first switching device, and the output end of the fourth logic device is connected to the second switching device.
[0026] In some embodiments, the first switching device and the second switching device are both MOS tubes. Accordingly, the output end of the third logic device is connected to the gate of the first switching device, the drain of the first switching device is connected to the power supply, the source of the first switching device is connected to the output end of the protection output sub-circuit, the output end of the fourth logic device is connected to the gate of the second switching device, the drain of the second switching device is connected to the output end of the protection output sub-circuit, and the source of the second switching device is grounded.
[0027] In some embodiments, the second logic device is a NOT gate, the third logic device is a NAND gate, and the fourth logic device is a NOR gate.
[0028] In a second aspect, the present application provides an electrical protection method, applied to the electrical protection device described in the first aspect or any embodiments of the first aspect, comprising:
[0029] Measuring the voltage value and the current value of the semiconductor under test during the dynamic parameter test by the measuring subcircuit, and sending the first voltage value and the second voltage value to the threshold judgment subcircuit;
[0030] The threshold judgment subcircuit judges the first voltage value, the second voltage value and the preset voltage threshold value, and sends a first signal for indicating the occurrence of the overvoltage and / or overcurrent phenomenon to the protection output subcircuit when it is determined that the overvoltage and / or overcurrent phenomenon occurs;
[0031] The second signal for shutting down the semiconductor under test output according to the first signal is sent to the semiconductor under test through the protection output subcircuit, so that the semiconductor under test is disconnected.
[0032] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:
[0033] The electrical protection device and method provided in the present application can set different voltage thresholds for protection according to different device test conditions. By detecting the voltage value and current value of the semiconductor under test, once an overvoltage and / or overcurrent situation occurs, a first signal used to characterize the occurrence of overvoltage and / or overcurrent is sent to the protection output subcircuit through the threshold judgment subcircuit. The protection output subcircuit outputs a second signal used to characterize the shutdown of the semiconductor under test, shuts down the semiconductor under test, and then cuts off the test loop. The response time and reliability are extremely high, avoiding the occurrence of accidents such as pipe explosion caused by overvoltage and / or overcurrent in the semiconductor under test during the dynamic parameter test, and ensuring the accuracy and safety of the semiconductor under test during the dynamic parameter test. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 is a schematic diagram of the structure of an electrical protection device provided in an embodiment of the present application;
[0035] Figure 2 It is a structural schematic diagram of a semiconductor dynamic parameter testing system provided in an embodiment of the present application;
[0036] Figure 3 It is a flow chart of the electrical protection method provided in the embodiment of the present application. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0038] The term "and / or" in this article is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " in this article indicates that the associated objects are in an or relationship, for example, A / B means A or B.
[0039] The terms "first" and "second" in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of objects. For example, a first signal and a second signal are used to distinguish different signals rather than to describe a specific order of signals.
[0040] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.
[0041] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.
[0042] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.
[0043] See also Figure 1 , an embodiment of the present application provides an electrical protection device, comprising:
[0044] The measuring subcircuit is used to measure the voltage value and current value of the semiconductor under test during the dynamic parameter test process, and send the first voltage value and the second voltage value to the threshold judgment subcircuit, the first voltage value is determined according to the voltage value, and the second voltage value is determined according to the current value;
[0045] The threshold judgment subcircuit is connected to the measurement subcircuit, and is used to judge the first voltage value, the second voltage value and the preset voltage threshold value, and when it is determined that an overvoltage and / or overcurrent phenomenon occurs, send a first signal used to indicate the occurrence of the overvoltage and / or overcurrent phenomenon to the protection output subcircuit;
[0046] The protection output subcircuit is used to output a second signal for shutting down the semiconductor under test according to the first signal, and send the second signal to the semiconductor under test to disconnect the semiconductor under test.
[0047] In the embodiment of the present application, the semiconductor under test can be a wide bandgap semiconductor. Wide bandgap semiconductor materials, also known as third-generation semiconductor materials, mainly include silicon carbide (SiC), gallium nitride (GaN), etc., which have the characteristics of high breakdown electric field, high saturation electron velocity, high thermal conductivity, high electron density, high mobility, etc., and are very suitable for making radiation-resistant, high-frequency, high-power and high-density integrated electronic devices. Devices made of the semiconductor materials under test, such as SiC and GaN power devices, have shown great technical advantages and application value in the fields of electric vehicles, smart grids, rail transit, and new energy grid connection.
[0048] The electrical protection device can be applied to the field of wide bandgap semiconductor testing. The electrical protection device specifically comprises a measurement subcircuit, a threshold judgment subcircuit connected to the measurement subcircuit, and a protection output subcircuit connected to the threshold judgment subcircuit.
[0049] The measurement subcircuit is used to measure the voltage value applied to the two ends of the semiconductor under test and the current value flowing through the semiconductor under test during the dynamic parameter test process. The dynamic parameter test process specifically refers to the double pulse test of the semiconductor under test under specific voltage and load conditions, and mainly focuses on the performance of the semiconductor under test during dynamic processes such as conduction and shutdown, including parameter indicators such as turn-on / off time and energy loss.
[0050] The threshold judgment subcircuit is used to judge whether the first voltage value determined according to the above voltage value and the second voltage value determined according to the above current value measured by the measurement subcircuit exceed the preset voltage threshold. Once it is determined that at least one of the overvoltage and overcurrent phenomena occurs, the protection output subcircuit will be triggered.
[0051] Specifically, when the threshold judgment subcircuit determines that an overvoltage and / or overcurrent phenomenon occurs, the protection output subcircuit is triggered by sending a first signal to the protection output subcircuit, wherein the first signal can be used to indicate the occurrence of at least one of the overvoltage and overcurrent phenomenon.
[0052] When the protection output subcircuit receives the first signal sent by the threshold judgment subcircuit, the protection output subcircuit outputs a protection action to disconnect the semiconductor under test, thereby disconnecting the test loop.
[0053] Specifically, when the protection output subcircuit receives the first signal, it outputs a second signal to the semiconductor under test, and the second signal can be used to shut down the semiconductor under test. After the semiconductor under test receives the second signal, the semiconductor under test is shut down, and then the test loop of the dynamic parameter test of the semiconductor under test is disconnected, thereby playing an overvoltage and overcurrent protection role.
[0054] The electrical protection device provided in the embodiment of the present application can set different voltage thresholds for protection according to different device test conditions. By detecting the voltage value and current value of the semiconductor under test, once an overvoltage and / or overcurrent situation occurs, a first signal used to characterize the occurrence of overvoltage and / or overcurrent is sent to the protection output subcircuit through the threshold judgment subcircuit. The protection output subcircuit outputs a second signal used to characterize the shutdown of the semiconductor under test, shuts down the semiconductor under test, and then cuts off the test loop. The response time and reliability are extremely high, avoiding the occurrence of accidents such as pipe explosion caused by overvoltage and / or overcurrent in the semiconductor under test during the dynamic parameter test, and ensuring the accuracy and safety of the semiconductor under test during the dynamic parameter test.
[0055] Furthermore, in some embodiments, the measurement subcircuit includes:
[0056] Voltage detection module and current detection module;
[0057] The voltage detection module includes a voltage-dividing resistor and a first operational amplifier. The voltage value at both ends of the semiconductor under test is input to the positive electrode of the first operational amplifier through the voltage-dividing resistor. The negative electrode of the first operational amplifier is connected to the output end of the first operational amplifier. The output end of the first operational amplifier is connected to the threshold judgment subcircuit.
[0058] The current detection module includes a sampling resistor and a second operational amplifier. The current information flowing through the semiconductor under test is input into the positive electrode of the second operational amplifier through the sampling resistor. The negative electrode of the second operational amplifier is connected to the output end of the second operational amplifier. The output end of the second operational amplifier is connected to the threshold judgment subcircuit.
[0059] Please continue to see Figure 1 The measurement subcircuit may include a voltage divider resistor RP, a sampling resistor RS, a first operational amplifier U1 and a second operational amplifier U2.
[0060] Among them, the voltage divider resistor RP and the first operational amplifier U1 constitute a voltage detection module, the voltage signal across the semiconductor to be tested is input to the positive electrode of the first operational amplifier U1 through the voltage divider resistor RP, the negative electrode of the first operational amplifier U1 is connected to the output end of the first operational amplifier U1, and the output end of the first operational amplifier U1 is then connected to the threshold judgment subcircuit, specifically connected to the positive electrode of the fifth operational amplifier U5 in the threshold judgment subcircuit.
[0061] The sampling resistor RS and the second operational amplifier U2 form a current detection module. The current signal of the semiconductor device to be tested is input to the positive electrode of the second operational amplifier U2 through the sampling resistor RS. The negative electrode of the second operational amplifier U2 is connected to the output end of the second operational amplifier U2. The output end of the second operational amplifier U2 is then connected to the threshold judgment subcircuit, specifically to the positive electrode of the sixth operational amplifier U6 in the threshold judgment subcircuit.
[0062] Furthermore, in some embodiments, the threshold determination subcircuit includes:
[0063] A first digital-to-analog converter, a second digital-to-analog converter, third to sixth operational amplifiers, and a first logic device;
[0064] The output end of the first digital-to-analog converter is connected to the positive electrode of the third operational amplifier, the negative electrode of the third operational amplifier is connected to the output end of the third operational amplifier, the output end of the third operational amplifier is connected to the negative electrode of the fifth operational amplifier, the positive electrode of the fifth operational amplifier is connected to the measurement sub-circuit, the output end of the fifth operational amplifier is connected to the first input end of the first logic device, the output end of the second digital-to-analog converter is connected to the positive electrode of the fourth operational amplifier, the negative electrode of the fourth operational amplifier is connected to the output end of the fourth operational amplifier, the output end of the fourth operational amplifier is connected to the negative electrode of the sixth operational amplifier, the positive electrode of the sixth operational amplifier is connected to the measurement sub-circuit, the output end of the sixth operational amplifier is connected to the second input end of the first logic device, and the output end of the first logic device is connected to the protection sub-circuit.
[0065] Please continue to see Figure 1 The threshold judgment sub-circuit includes a third operational amplifier U3 to a sixth operational amplifier U6, a first digital-to-analog converter U7 (DAC), a second digital-to-analog converter U8 and a first logic device.
[0066] Further, in some embodiments, the first logic device is an OR gate.
[0067] In the embodiment of the present application, the first logic device is an OR gate G1.
[0068] The output end of the first digital-to-analog converter U7 is connected to the positive electrode of the third operational amplifier U3, and the negative electrode of the third operational amplifier U3 is connected to the output end of the third operational amplifier U3; the output end of the second digital-to-analog converter U8 is connected to the positive electrode of the fourth operational amplifier U4, and the negative electrode of the fourth operational amplifier U4 is connected to the output end of the fourth operational amplifier U4; the positive electrode of the fifth operational amplifier U5 is connected to the output end of the first operational amplifier U1 in the measurement subcircuit, and the negative electrode of the fifth operational amplifier U5 is connected to the output end of the third operational amplifier U3; the positive electrode of the sixth operational amplifier U6 is connected to the output end of the second operational amplifier U2 in the measurement subcircuit, and the negative electrode of the sixth operational amplifier U6 is connected to the output end of the fourth operational amplifier U4; the two input ends (the first input end and the second input end) of the first logic device or gate G1 are respectively connected to the output ends of the fifth operational amplifier U5 and the sixth operational amplifier U6, wherein the first input end of the first logic device or gate G1 is connected to the output end of the fifth operational amplifier U5, and the second input end of the first logic device or gate G1 is connected to the output end of the sixth operational amplifier U6.
[0069] The electrical protection device provided in the embodiment of the present application monitors the voltage and current of the semiconductor device under test in real time and makes judgments by designing a voltage detection module, a current detection module and a threshold judgment subcircuit. All voltage measurements and outputs are followed by an operational amplifier circuit with a driving amplification function, thereby further improving the accuracy and stability of the electrical protection device.
[0070] Furthermore, in some embodiments, the electrical protection device may also include:
[0071] The controller is connected to the threshold judgment subcircuit and is used to set the voltage thresholds of the first digital-to-analog converter and the second digital-to-analog converter.
[0072] Please continue to see Figure 1 The electrical protection device also includes a controller connected to the threshold judgment subcircuit. More specifically, the controller is connected to the first digital-to-analog converter U7 and the second digital-to-analog converter U8 in the threshold judgment subcircuit.
[0073] The controller can be used to set the voltage thresholds of the first digital-to-analog converter U7 and the second digital-to-analog converter U8.
[0074] Furthermore, in some embodiments, the threshold determination subcircuit is further configured to:
[0075] When a first voltage value at the output terminal of the first operational amplifier is greater than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output terminal of the second operational amplifier is less than a voltage threshold of the second digital-to-analog converter, determining that an overvoltage phenomenon occurs;
[0076] When a first voltage value at the output terminal of the first operational amplifier is less than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output terminal of the second operational amplifier is greater than a voltage threshold of the second digital-to-analog converter, determining that an overcurrent phenomenon occurs;
[0077] When a first voltage value at the output end of the first operational amplifier is greater than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output end of the second operational amplifier is greater than a voltage threshold of the second digital-to-analog converter, it is determined that overvoltage and overcurrent phenomena occur.
[0078] In an embodiment of the present application, the threshold judgment subcircuit can be used to judge whether overvoltage and / or overcurrent occurs based on the voltage threshold of the first digital-to-analog converter U7, the voltage threshold of the second digital-to-analog converter U8, the voltage value of the output end of the first operational amplifier U1 (the voltage value is the first voltage value), and the voltage value of the output end of the second operational amplifier U2 (the voltage value is the second voltage value) set by the controller.
[0079] Specifically, if the first voltage value at the output end of the first operational amplifier U1 is greater than the voltage threshold of the first digital-to-analog converter U7, and the second voltage value at the output end of the second operational amplifier U2 is less than the voltage threshold of the second digital-to-analog converter U8, the threshold judgment subcircuit determines that an overvoltage phenomenon occurs.
[0080] Among them, the first voltage value of the output end of the first operational amplifier U1 can be obtained according to the voltage value across the semiconductor under test measured by the voltage detection module in the measurement sub-circuit; the second voltage value of the output end of the second operational amplifier U2 can be obtained according to the current value flowing through the semiconductor under test measured by the current detection module.
[0081] Please continue to see Figure 1 , the voltage amplitude of the positive input terminal of the first operational amplifier U1 is μV DS , where μ is the attenuation ratio of the voltage divider resistor RP, V DS is the voltage value at both ends of the semiconductor under test; the voltage amplitude at the positive input terminal of the second operational amplifier U2 is I RUS ×R S , where I RUS is the current value passing through the semiconductor under test, R S is the resistance of the sampling resistor RS.
[0082] If the first voltage value at the output end of the first operational amplifier U1 is less than the voltage threshold of the first digital-to-analog converter U7, and the second voltage value at the output end of the second operational amplifier U2 is greater than the voltage threshold of the second digital-to-analog converter U8, the threshold judgment subcircuit judges that an overcurrent phenomenon occurs.
[0083] If the first voltage value at the output end of the first operational amplifier U1 is greater than the voltage threshold of the first digital-to-analog converter U7, and the second voltage value at the output end of the second operational amplifier U2 is greater than the voltage threshold of the second digital-to-analog converter U8, the threshold judgment subcircuit determines that overvoltage and overcurrent occur.
[0084] If the first voltage value at the output end of the first operational amplifier U1 is less than the voltage threshold of the first digital-to-analog converter U7, and the second voltage value at the output end of the second operational amplifier U2 is less than the voltage threshold of the second digital-to-analog converter U8, the threshold judgment subcircuit determines that no overvoltage and / or overcurrent occurs.
[0085] Furthermore, in some embodiments, the protection output subcircuit may include:
[0086] A second logic device to a fourth logic device, a first switching device and a second switching device;
[0087] The input end of the second logic device is connected to the threshold judgment subcircuit, the output end of the second logic device is connected to the first input end of the fourth logic device, the second input end of the fourth logic device is grounded, the first input end of the third logic device is connected to the threshold judgment subcircuit, the second input end of the third logic device is grounded, the output end of the third logic device is connected to the first switching device, and the output end of the fourth logic device is connected to the second switching device.
[0088] Please continue to see Figure 1 , the protection output sub-circuit may include a second logic device, a third logic device, a fourth logic device, a first switching device and a second switching device.
[0089] Among them, the input end of the second logic device is connected to the threshold judgment sub-circuit, the output end of the second logic device is connected to the first input end of the fourth logic device, the second input end of the fourth logic device is grounded, the first input end of the third logic device is connected to the threshold judgment sub-circuit, the second input end of the third logic device is grounded, the output end of the third logic device is connected to the first switching device Q1, and the output end of the fourth logic device is connected to the second switching device Q2.
[0090] Further, in some embodiments, the first switching device and the second switching device are both MOS tubes, and accordingly, the output end of the third logic device is connected to the gate of the first switching device, the drain of the first switching device is connected to the power supply, the source of the first switching device is connected to the output end of the protection output sub-circuit, the output end of the fourth logic device is connected to the gate of the second switching device, the drain of the second switching device is connected to the output end of the protection output sub-circuit, and the source of the second switching device is grounded.
[0091] In the embodiment of the present application, the first switch device Q1 and the second switch device Q2 are both MOS tubes. The output end of the third logic device is connected to the gate of the first switch device Q1, the drain of the first switch device Q1 is connected to the power supply VDD, the source of the first switch device Q1 is connected to the output end OUT of the protection output sub-circuit, the output end of the fourth logic device is connected to the gate of the second switch device Q2, the drain of the second switch device Q2 is connected to the output end OUT of the protection output sub-circuit, and the source of the second switch device Q2 is grounded.
[0092] Further, in some embodiments, the second logic device is a NOT gate, the third logic device is a NAND gate, and the fourth logic device is a NOR gate.
[0093] In the embodiment of the present application, the second logic device is a NOT gate G2, the third logic device is a NAND gate G3, and the fourth logic device is a NOR gate G4.
[0094] The input end of the NOT gate G2 is connected to the output end of G1 in the threshold judgment subcircuit, and the output end of the NOT gate G2 is connected to the input end of the NOR gate G4; the other input end of the NOR gate G4 is connected to the input end of the NAND gate G3; the other input end of the NAND gate G3 is connected to the output end of the OR gate G1, and the output end of the NAND gate G3 is connected to the gate of the switching device Q1; the output end of the NOR gate G4 is connected to the gate of the switching device Q2; the drain of the switching device Q1 is connected to the power supply VDD, and the source of the switching device Q1 is connected to the output end OUT of the protection output subcircuit; the drain of the switching device Q2 is connected to the output end OUT of the protection output subcircuit, and the source of the switching device Q2 is grounded.
[0095] Exemplarily, the voltage measurement module is composed of a voltage divider resistor RP and a first operational amplifier U1, and the voltage amplitude of the positive input terminal of the first operational amplifier U1 is μV DS RP can be a high-power, high-voltage resistor, and the voltage divider ratio should be reasonable. For example, the voltage value across the semiconductor under test is 1500V. The 1500V test voltage is divided by the voltage divider resistor RP with a voltage divider ratio of 1:100 and then transmitted to the next level voltage amplitude Us1=15V, which is then processed and compared. Us1 is the first voltage value at the output of the first operational amplifier U1.
[0096] The current measurement module is composed of a sampling resistor RS and a second operational amplifier U2. The voltage amplitude of the positive input terminal of the second operational amplifier U2 is I RUS ×R S , where I RUS is the current value passing through the semiconductor under test, R S is the resistance value of the sampling resistor RS. For example, if the current flowing through the semiconductor under test is 500A, the voltage amplitude transmitted to the next stage after passing through the 20mΩ sampling resistor RS is US2=10V. Among them, US2 is the second voltage value of the output terminal of the second operational amplifier U2.
[0097] The first operational amplifier U1 and the second operational amplifier U2 in the measurement subcircuit play the role of voltage follower, further improving the stability and driving capability of the measurement voltage.
[0098] A threshold judgment subcircuit, used to judge whether an overvoltage and / or overcurrent phenomenon occurs;
[0099] Specifically, the threshold judgment subcircuit includes the third operational amplifier U3 to the sixth operational amplifier U6, the first digital-to-analog converter U7, the second digital-to-analog converter U8, and the first logic device or gate G1. Among them, the fifth operational amplifier U5 and the sixth operational amplifier U6 play the role of voltage comparison.
[0100] Before the test starts, the controller sets the output voltage threshold Ugate for the first digital-to-analog converter U7 and the second digital-to-analog converter U8, assuming that both are 20V, that is, Ugate1=Ugate2=20V, where Ugate1 is the voltage threshold of the first digital-to-analog converter U7, and Ugate2 is the voltage threshold of the second digital-to-analog converter U8; after receiving the measurement voltages Us1 and Us2 transmitted by the measurement subcircuit, after the follow-up action of the third operational amplifier U3 and the fourth operational amplifier U4, they are compared with the voltage thresholds Ugate1 and Ugate2, and then output through the first logic device or gate G1. The specific logic is shown in Table 1:
[0101] Table 1
[0102]
[0103] Please see further Figure 2 The electrical protection device includes two inputs and one output, namely voltage measurement input, current measurement input and overvoltage and overcurrent output. The voltage measurement input channel is connected to the voltage V at both ends of the semiconductor under test. DS , the current measurement input channel is connected to the sampling resistor RS, and the current I of the semiconductor under test is indirectly measured through the sampling resistor RS RUS The sampling resistor RS is connected in series with the semiconductor under test in the test circuit; the output terminal OUT of the electrical protection device is connected to the gate of the semiconductor under test. TEST 、Inductance L BUS , capacitor C BUS and high voltage power supply. When there is no overvoltage and / or overcurrent phenomenon, the semiconductor Q TEST Driven by a dual-pulse drive module, dynamic parameter testing is performed.
[0104] Select the semiconductor to be tested and set the voltage threshold through the controller before starting the test;
[0105] At the beginning of the test, the semiconductor under test is in the on state. The measurement subcircuit monitors the voltage and current of the semiconductor under test and inputs them into the threshold judgment subcircuit. When at least one of overcurrent and overvoltage occurs, the output terminal OUT of the electrical protection device instantly outputs a low level, making the semiconductor under test Q TEST The gate and source voltage difference V GS =0, thereby shutting down the semiconductor under test and disconnecting the test circuit, thereby playing a protective role; conversely, when the voltage and current are normal, the output terminal OUT is in a high-impedance state and does not affect the normal operation of the test circuit.
[0106] The electrical protection device provided in the embodiment of the present application designs a threshold judgment subcircuit and a protection output subcircuit based on logic gate devices, and utilizes the stability and low latency of logic gates to enable the electrical protection device to have an extremely fast instantaneous response speed, which can reach the microsecond level, meeting the time requirements in the dynamic parameter test of the semiconductor under test.
[0107] The electrical protection method provided by the present application is described below. The electrical protection method described below can be applied to the electrical protection device described above.
[0108] See also Figure 3 , an embodiment of the present application provides an electrical protection amplification, including: step 110, step 120 and step 130.
[0109] Step 110 measures the voltage value and the current value of the semiconductor under test during the dynamic parameter test by the measuring subcircuit, and sends the first voltage value and the second voltage value to the threshold judgment subcircuit;
[0110] Step 120: The threshold judgment subcircuit judges the first voltage value, the second voltage value and the preset voltage threshold value, and when it is determined that an overvoltage and / or overcurrent phenomenon occurs, sends a first signal for indicating the occurrence of the overvoltage and / or overcurrent phenomenon to the protection output subcircuit;
[0111] In step 130, the protection output subcircuit sends a second signal for shutting down the semiconductor under test output according to the first signal to the semiconductor under test, so that the semiconductor under test is disconnected.
[0112] The electrical protection method provided in the embodiment of the present application can set different voltage thresholds for protection according to different device test conditions. By detecting the voltage value and current value of the semiconductor under test, once an overvoltage and / or overcurrent situation occurs, a first signal used to characterize the occurrence of overvoltage and / or overcurrent is sent to the protection output subcircuit through the threshold judgment subcircuit. The protection output subcircuit outputs a second signal used to characterize the shutdown of the semiconductor under test, shuts down the semiconductor under test, and then cuts off the test loop. The response time and reliability are extremely high, avoiding the occurrence of accidents such as pipe explosion caused by overvoltage and / or overcurrent in the semiconductor under test during the dynamic parameter test, and ensuring the accuracy and safety of the semiconductor under test during the dynamic parameter test.
[0113] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.
[0114] In addition, in the present application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.
[0115] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.
[0116] In addition, in the embodiments of the present application, the mathematical concepts mentioned are symmetry, equality, parallelism, verticality, etc. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense, and allow a small amount of deviation, approximation to symmetry, approximation to equality, approximation to parallelism, approximation to verticality, etc. are all possible. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.
[0117] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.
Claims
1. An electrical protection device, characterized in that: include: A measurement subcircuit, a threshold judgment subcircuit and a protection output subcircuit; The measuring subcircuit is used to measure the voltage value and the current value of the semiconductor under test during the dynamic parameter test process, and send the first voltage value and the second voltage value to the threshold judgment subcircuit, the first voltage value is determined according to the voltage value, and the second voltage value is determined according to the current value; The threshold judgment subcircuit is connected to the measurement subcircuit, and is used to judge the first voltage value, the second voltage value and the preset voltage threshold, and when it is determined that an overvoltage and / or overcurrent phenomenon occurs, send a first signal used to indicate the occurrence of the overvoltage and / or overcurrent phenomenon to the protection output subcircuit; The protection output subcircuit is used to output a second signal for shutting down the semiconductor under test according to the first signal, and send the second signal to the semiconductor under test to disconnect the semiconductor under test.
2. The electrical protection device according to claim 1, characterized in that: The measurement subcircuit comprises: Voltage detection module and current detection module; The voltage detection module includes a voltage-dividing resistor and a first operational amplifier, the voltage value across the semiconductor under test is input to the positive electrode of the first operational amplifier through the voltage-dividing resistor, the negative electrode of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier is connected to the threshold judgment subcircuit; The current detection module includes a sampling resistor and a second operational amplifier. The current information flowing through the semiconductor under test is input into the positive electrode of the second operational amplifier through the sampling resistor. The negative electrode of the second operational amplifier is connected to the output end of the second operational amplifier. The output end of the second operational amplifier is connected to the threshold judgment sub-circuit.
3. The electrical protection device according to claim 2, characterized in that: The threshold judgment subcircuit comprises: A first digital-to-analog converter, a second digital-to-analog converter, third to sixth operational amplifiers, and a first logic device; The output end of the first digital-to-analog converter is connected to the positive electrode of the third operational amplifier, the negative electrode of the third operational amplifier is connected to the output end of the third operational amplifier, the output end of the third operational amplifier is connected to the negative electrode of the fifth operational amplifier, the positive electrode of the fifth operational amplifier is connected to the measurement sub-circuit, the output end of the fifth operational amplifier is connected to the first input end of the first logic device, the output end of the second digital-to-analog converter is connected to the positive electrode of the fourth operational amplifier, the negative electrode of the fourth operational amplifier is connected to the output end of the fourth operational amplifier, the output end of the fourth operational amplifier is connected to the negative electrode of the sixth operational amplifier, the positive electrode of the sixth operational amplifier is connected to the measurement sub-circuit, the output end of the sixth operational amplifier is connected to the second input end of the first logic device, and the output end of the first logic device is connected to the protection sub-circuit.
4. The electrical protection device according to claim 3, characterized in that: Also includes: A controller is connected to the threshold judgment subcircuit and is used to set voltage thresholds of the first digital-to-analog converter and the second digital-to-analog converter.
5. The electrical protection device according to claim 4, characterized in that: The threshold judgment subcircuit is also used for: When a first voltage value at the output terminal of the first operational amplifier is greater than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output terminal of the second operational amplifier is less than a voltage threshold of the second digital-to-analog converter, determining that an overvoltage phenomenon occurs; When a first voltage value at the output terminal of the first operational amplifier is less than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output terminal of the second operational amplifier is greater than a voltage threshold of the second digital-to-analog converter, determining that an overcurrent phenomenon occurs; When a first voltage value at the output end of the first operational amplifier is greater than a voltage threshold of the first digital-to-analog converter, and a second voltage value at the output end of the second operational amplifier is greater than a voltage threshold of the second digital-to-analog converter, it is determined that overvoltage and overcurrent phenomena occur.
6. The electrical protection device according to claim 3, characterized in that: The first logic device is an OR gate.
7. The electrical protection device according to claim 1, characterized in that: The protection output subcircuit comprises: A second logic device to a fourth logic device, a first switching device and a second switching device; The input end of the second logic device is connected to the threshold judgment sub-circuit, the output end of the second logic device is connected to the first input end of the fourth logic device, the second input end of the fourth logic device is grounded, the first input end of the third logic device is connected to the threshold judgment sub-circuit, the second input end of the third logic device is grounded, the output end of the third logic device is connected to the first switching device, and the output end of the fourth logic device is connected to the second switching device.
8. The electrical protection device according to claim 7, characterized in that: The first switch device and the second switch device are both MOS tubes. Accordingly, the output end of the third logic device is connected to the gate of the first switch device, the drain of the first switch device is connected to the power supply, the source of the first switch device is connected to the output end of the protection output sub-circuit, the output end of the fourth logic device is connected to the gate of the second switch device, the drain of the second switch device is connected to the output end of the protection output sub-circuit, and the source of the second switch device is grounded.
9. The electrical protection device according to claim 7, characterized in that: The second logic device is a NOT gate, the third logic device is a NAND gate, and the fourth logic device is a NOR gate.
10. An electrical protection method, characterized in that: The electrical protection device according to any one of claims 1 to 9 comprises: Measuring the voltage value and the current value of the semiconductor under test during the dynamic parameter test by the measuring subcircuit, and sending the first voltage value and the second voltage value to the threshold judgment subcircuit; The threshold judgment subcircuit judges the first voltage value, the second voltage value and the preset voltage threshold, and when it is determined that an overvoltage and / or overcurrent phenomenon occurs, sends a first signal for indicating the occurrence of the overvoltage and / or overcurrent phenomenon to the protection output subcircuit; A second signal for shutting down the semiconductor under test output according to the first signal is sent to the semiconductor under test through the protection output subcircuit, so that the semiconductor under test is disconnected.