Repeated switch test circuit and method for SiC high-temperature-resistant gate drive integrated circuit

Abstract

The invention relates to the field of electronic component testing, and solves the problem of testing the switch driving stability and reliability of a SiC high-temperature-resistant gate driving integrated circuit at 400 DEG C. The circuit comprises an adjustable power supply input (1), a driving signal circuit (2), a power circuit (3), a capacitor charging and discharging circuit (4), a voltage signal amplification circuit (5), a comparison circuit (6) and a signal acquisition and recording interface circuit (7). According to the invention, the repeated switch test of the SiC high-temperature-resistant gate drive integrated circuit within 400 DEG C or even a wider range can be realized, the switch-on and switch-off processes of the drive and power MOSFET are associated with the charging and discharging processes of the capacitor, and automatic switching of high and low levels of the drive is realized through the comparator. The method is suitable for testing the SiC high-temperature-resistant gate drive integrated circuit.

Description

Technical Field

[0001] The present invention relates to the field of electronic component testing, and in particular to a SiC high temperature resistant gate drive integrated circuit repeated switching test circuit and method. Background Art

[0002] High temperature driver chip is a circuit suitable for controlling power switching devices (such as MOSFET tubes) in high temperature environments. Its high temperature resistance, high efficiency, reliable and safe driving performance make it widely used in the field of power electronics, such as aircraft engine ignition and aviation power distribution in higher airspace and faster speed domains. However, there is little research and verification on the long-term stability and reliability of the switch drive of driver chips in high temperature environments in combination with product requirements. Therefore, it is particularly important to efficiently and long-term test the switch drive stability and reliability of SiC high temperature gate driver integrated circuits in high temperature environments. Summary of the invention

[0003] Purpose of the invention: The present invention provides a SiC high temperature resistant gate drive integrated circuit repeated switch test circuit and method to solve the problem of switch drive stability and reliability testing of SiC high temperature resistant gate drive integrated circuit at 400°C.

[0004] The technical solution of the present invention:

[0005] A SiC high temperature resistant gate drive integrated circuit repeated switch test circuit, comprising: an adjustable power supply input 1, a drive signal circuit 2, a power circuit 3, a capacitor charge and discharge circuit 4, a voltage signal amplification circuit 5, a comparison circuit 6, and a signal acquisition and recording interface circuit 7;

[0006] The adjustable power input 1 provides driving power for the driving signal circuit 2, provides chip working power for the voltage signal amplifying circuit 5, the SiC high temperature resistant gate driving integrated circuit under test, and the comparison circuit 6, and provides a reference voltage for the comparison circuit 6;

[0007] The driving signal circuit 2 provides a driving signal for the SiC high temperature resistant gate driving integrated circuit under test;

[0008] The power circuit 3 receives a driving signal of the SiC high temperature resistant gate driving integrated circuit under test, and the power circuit 3 is turned on when the driving signal is high, and the power circuit 3 is turned off when the driving signal is low;

[0009] The capacitor charging and discharging circuit 4 charges when the power circuit 3 is turned on, and discharges when the power circuit 3 is turned off;

[0010] The voltage signal amplifying circuit 5 amplifies the voltage signal output by the capacitor charging and discharging circuit 4;

[0011] The comparison circuit 6 compares the voltage signal from the voltage signal amplifying circuit 5 with the reference voltage. If the voltage signal from the voltage signal amplifying circuit 5 is higher than the reference voltage, the comparison circuit 6 outputs a low level to the driving signal circuit 2. If the voltage signal from the voltage signal amplifying circuit 5 is lower than the reference voltage, the comparison circuit 6 outputs a high level to the driving signal circuit 2.

[0012] The signal acquisition and recording interface circuit 7 is used to record the driving signal output by the driving signal circuit 2 , the driving signal input and output by the power circuit 3 , and the voltage signal input by the voltage signal amplifying circuit 5 .

[0013] The adjustable power input 1 includes three power supplies, one of which is a driving power supply, with the positive output terminal being Power+ and the negative output terminal being GND. It has an adjustable output voltage function and provides a driving power supply for the driving signal circuit 2; one is a chip working power supply, with the positive output terminal being VCC and the negative output terminal being GND, and provides a working power supply for the SiC high temperature resistant gate driving integrated circuit under test, the voltage signal amplifying circuit 5, and the comparison circuit 6; one is a reference power supply, with the positive output terminal being Vf and the negative output terminal being GND, and outputs a reference voltage, which is used as a comparison reference voltage in the comparison circuit 6.

[0014] The driving signal circuit 2 includes a driving resistor R1 and a diode D1. The driving power supply output Power+ is connected to one end of the driving resistor R1. The other end of the driving resistor R1 is connected to the VIN pin of the SiC high temperature resistant gate driving integrated circuit U1 under test, the positive electrode of the diode D1, and the negative electrode of the voltage regulator diode D2 in the power circuit 3. The negative electrode of the diode D1 is connected to the OUT pin of the comparator U3 of the comparison circuit 6.

[0015] The power circuit 3 includes a voltage-stabilizing diode D2 and a power MOSFET tube U2; the driving power supply output Power+ is connected to the drain of the power MOSFET tube, the gate of the power MOSFET tube is connected to the VOUT pin of the SiC high-temperature-resistant gate drive integrated circuit U1 under test, and the source of the power MOSFET tube is connected to the positive electrode of the voltage-stabilizing diode D2.

[0016] The capacitor charging and discharging circuit 4 includes a current limiting resistor R2, a charging capacitor C1, and a voltage dividing resistor R3; one end of the current limiting resistor R2 is connected to the source of the power MOSFET tube of the power circuit 3, the charging capacitor C1 is connected between the other end of the current limiting resistor R2 and GND, and the voltage dividing resistor R3 is connected between the source of the power MOSFET tube of the power circuit 3 and GND.

[0017] The voltage signal amplifying circuit 5 includes an amplifier U4, a first resistor R4, a second resistor R5, a third resistor R6 and a capacitor C2. One end of the first resistor R4 is connected to the in-phase input end of the amplifier U4, and the other end of the first resistor R4 is connected between the current limiting resistor R2 and the charging capacitor C1 of the capacitor charging and discharging circuit 4; the inverting input end of the amplifier U4 is connected to the output end of the amplifier U4 through the second resistor R5, and the inverting input end of the amplifier U4 is connected to GND through the third resistor R6, and the capacitor C2 is connected in parallel at both ends of the second resistor R5.

[0018] The comparison circuit 6 includes a comparator U3, an IN+ pin of the comparator U3 is connected to the reference voltage output Vf of the adjustable power supply input 1, an IN- pin of the comparator U3 is connected to the output pin of the amplifier U4 of the voltage signal amplification circuit 5, and an OUT pin of the comparator U3 is connected to the cathode of the diode D1 of the drive signal circuit 2.

[0019] The signal acquisition and recording interface circuit 7 acquires the voltage V1 between the driving resistor R1 and the diode D1, the voltage V2 of the VOUT pin of the SiC high temperature resistant gate driving integrated circuit under test, and the voltages V3 and V4 across the current limiting resistor R2.

[0020] A method for repeated switching test of SiC high temperature resistant gate drive integrated circuit,

[0021] The test circuit opening working process: the driving power supply outputs Power+, the OUT pin output of the comparator U3 is high level, the diode D1 is cut off, and the voltage at point V1 is high level, that is, the VIN pin input of the SiC high temperature resistant gate drive integrated circuit U1 under test is high level. At this time, the test circuit is in the test opening mode, and the driving signal circuit 2 is connected to the front end of the SiC high temperature resistant gate drive integrated circuit under test to provide it with an opening driving voltage signal. The VOUT pin of the SiC high temperature resistant gate drive integrated circuit U1 under test outputs a high level, and the drain and source of the power MOSFET tube are turned on; the capacitor C1 is in a charging state, and the current limiting resistor R2 plays a current limiting role. The voltage V4 across C1 gradually increases and is amplified by the circuit. The voltage value is V5, and the amplification ratio is 1+R5 / R6;

[0022] In the comparison circuit 6, when V5 exceeds the reference voltage Vf, the OUT pin of the comparator U3 outputs a low level; at this time, a turn-on process test is completed and it will automatically switch to a turn-off process test.

[0023] A method for repeated switching test of SiC high temperature resistant gate drive integrated circuit,

[0024] The shutdown working process of the test circuit: the OUT pin output of the comparator U3 is low level, the diode D1 is turned on, and the voltage at point V1 is low level, that is, the VIN pin input of the SiC high temperature resistant gate drive integrated circuit U1 under test is low level. At this time, the test circuit is in the test shutdown mode, and the drive signal circuit 2 is connected to the front end of the SiC high temperature resistant gate drive integrated circuit under test to provide it with a disconnect drive voltage signal; the VOUT pin of the SiC high temperature resistant gate drive integrated circuit U1 under test outputs a low level, and the drain and source of the power MOSFET tube are not conducting; the capacitor C1 is in a discharge state, and forms a discharge circuit with the resistor R2 and the resistor R3. The voltage V4 at both ends of C1 gradually decreases and is amplified by the amplifier circuit. The voltage value is V5, and the amplification ratio is 1+R5 / R6; in the comparison circuit 6, V5 is lower than the reference voltage Vf, and the OUT pin of the comparator U3 outputs a high level; at this time, a shutdown process test is completed and it will automatically switch to a turn-on process test.

[0025] The beneficial effects of the present invention are as follows: the present invention can realize repeated switching tests of SiC high temperature resistant gate drive integrated circuits at 400°C or even wider, associate the on and off processes of the drive and power MOSFET tubes with the charging and discharging processes of the capacitor, and realize automatic switching of the high and low levels of the drive through a comparator. The circuit is simple and reliable, the test cycle is carried out without manual intervention, and the test efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a principle block diagram of a SiC high temperature resistant gate drive integrated circuit test circuit of the present invention;

[0027] Figure 2 The present invention is a schematic diagram of the design principle of the SiC high temperature resistant gate drive integrated circuit test circuit. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1As shown, the SiC high temperature resistant gate drive integrated circuit repeated switching test circuit is connected to the input and output ends of the SiC high temperature resistant gate drive integrated circuit under test between the power supply and the signal acquisition and recording equipment, and the SiC high temperature resistant gate drive integrated circuit under test is placed in a high temperature environment. The SiC high temperature resistant gate drive integrated circuit repeated switching test circuit can be divided into: adjustable power supply input 1, SiC high temperature resistant gate drive integrated circuit under test, drive signal circuit 2, power circuit 3, capacitor charging and discharging circuit 4, voltage signal amplification circuit 5, comparison circuit 6, signal acquisition and recording interface circuit 7.

[0030] like Figure 2 As shown, the SiC high temperature resistant gate drive integrated circuit repeated switch test circuit is composed of the tested SiC high temperature resistant gate drive integrated circuit U1, drive resistor R1, diode D1, voltage stabilizing diode D2, metal-oxide semiconductor field effect transistor power MOSFET tube U2, current limiting resistor R2, charging capacitor C1, voltage dividing resistor R3, amplifier U4, resistor R4, resistor R5, resistor R6 and capacitor C2, and comparator U3. The Power+ of the adjustable power input 1 is connected to the input of the drive signal circuit 2; the reference voltage Vf of the adjustable power input 1 is connected to the input IN+ of the comparator of the comparison circuit 6; the VCC of the adjustable power input 1 is connected to the working power supply of the tested gate drive integrated circuit, the working power supply of the comparator of the comparison circuit 6, and the working power supply of the amplifier of the voltage signal amplifier circuit 5; the output of the drive signal circuit 2 is connected to the input of the tested gate drive integrated circuit, the output of the tested gate drive integrated circuit is connected to the power circuit 3, the power circuit 3 is connected to the capacitor charging and discharging circuit 4, the capacitor charging and discharging circuit 4 is connected to the voltage signal amplifier circuit 5, the output of the voltage signal amplifier circuit 5 is connected to one end input of the comparison circuit 6, and the output of the comparison circuit 6 is connected to the drive signal circuit 2.

[0031] The SiC high temperature resistant gate drive integrated circuit repeated switching test circuit can be divided into: adjustable power supply input 1, SiC high temperature resistant gate drive integrated circuit under test, drive signal circuit 2, power circuit 3, capacitor charging and discharging circuit 4, voltage signal amplification circuit 5, comparison circuit 6, signal acquisition and recording interface circuit 7.

[0032] The adjustable power input 1 includes three power supplies, one of which is a driving power supply, with the positive output terminal being Power+ and the negative output terminal being GND. It has an adjustable output voltage function and can test the input voltage range for the effective operation of the SiC high-temperature resistant gate drive integrated circuit under test; one is a chip working power supply, with the positive output terminal being VCC and the negative output terminal being GND, which provides working power for the tested iC high-temperature resistant gate drive integrated circuit, amplifier chip, and comparator chip; one is a reference power supply, with the positive output terminal being Vf and the negative output terminal being GND, which outputs a reference voltage and is used as a comparison reference voltage in the comparison circuit 6.

[0033] The driving signal circuit 2 includes a driving resistor R1 and a diode D1. The driving power supply output Power+ is connected to one end of the driving resistor R1. The other end of the driving resistor R1 is connected to the VIN pin of the SiC high temperature resistant gate driving integrated circuit U1 under test, the positive electrode of the diode D1, and the negative electrode of the voltage regulator diode D2. The negative electrode of the diode D1 is connected to the OUT pin of the comparator U3.

[0034] The power circuit 3 includes a voltage-stabilizing diode D2 and a metal-oxide semiconductor field-effect transistor (power MOSFET) U2. The driving power supply output Power+ is connected to the drain of the power MOSFET. The gate of the power MOSFET is connected to the VOUT pin of the SiC high-temperature-resistant gate drive integrated circuit U1 under test. The source of the power MOSFET is connected to the positive electrode of the voltage-stabilizing diode D2.

[0035] The capacitor charging and discharging circuit 4 includes a current limiting resistor R2, a charging capacitor C1, and a voltage dividing resistor R3. One end of the current limiting resistor R2 is connected to the source of the power MOSFET tube, the charging capacitor C1 is connected between the other end of the current limiting resistor R2 and GND, and the voltage dividing resistor R3 is connected between the source of the power MOSFET tube and GND.

[0036] The voltage signal amplifying circuit 5 includes an amplifier U4, a resistor R4, a resistor R5, a resistor R6 and a capacitor C2. The resistor R4 is connected to the non-inverting input terminal of the amplifier U4, the inverting input terminal of the amplifier U4 is connected to the resistor R5 to the output terminal, the inverting input terminal of the amplifier U4 is connected to the resistor R6 to GND, and the capacitor C2 is connected in parallel across the resistor R5.

[0037] The IN+ pin of the comparator U3 in the comparison circuit 6 is connected to the reference voltage output Vf, the IN- pin of the comparator U3 is connected to the output pin of the amplifier chip U4, and the OUT pin of the comparator U3 is connected to the cathode of the diode D1.

[0038] The signal acquisition and recording interface circuit 7 includes voltage sampling points V1, V2, V3, and V4; the voltage sampling point V1 is connected to the gate integrated drive input signal VIN under test; the voltage sampling point V2 is connected to the gate integrated drive output signal VOUT under test; the voltage sampling point V3 is connected to the drain of the MOSFET tube; and the voltage sampling point V4 is connected between the capacitor C1 and the current limiting resistor R2.

[0039] The working process of the test circuit driving voltage range test is as follows: adjust the driving power supply output Power+ voltage. When the driving voltage conditions are met, the test circuit has the repeated switching conditions for testing the SiC high temperature resistant gate drive integrated circuit; when the driving voltage conditions are not met, the test circuit does not have the repeated switching conditions for testing the SiC high temperature resistant gate drive integrated circuit, the SiC high temperature resistant gate drive integrated circuit is in a non-working state, and the power MOSFET tube is not turned on.

[0040] The test circuit opening process: the driving power supply outputs Power+, the OUT pin of the comparator U3 outputs a high level, the diode is cut off, and the voltage at point V1 is a high level, that is, the VIN pin input of the SiC high temperature resistant gate driver integrated circuit U1 under test is a high level. At this time, the test circuit is in the test opening mode, and the driving signal circuit 2 is connected to the front end of the SiC high temperature resistant gate driver integrated circuit under test to provide it with an opening driving voltage signal. The VOUT pin of the SiC high temperature resistant gate driver integrated circuit U1 under test outputs a high level, and the drain and source of the power MOSFET are turned on. The capacitor C1 is in a charging state, and the current limiting resistor R2 plays a current limiting role. The voltage V4 across C1 gradually increases and is amplified by the circuit. The voltage value is V5, and the amplification ratio is (1+R5 / R6).

[0041] In the comparison circuit 6, V5 exceeds the reference voltage Vf, and the OUT pin of the comparator U3 outputs a low level. At this time, a turn-on process test is completed and will automatically switch to a turn-off process test.

[0042] The shutdown working process of the test circuit: the OUT pin of the comparator U3 outputs a low level, the diode is turned on, and the voltage at point V1 is a low level, that is, the VIN pin input of the SiC high temperature resistant gate driver integrated circuit U1 under test is a low level. At this time, the test circuit is in the test shutdown mode, and the drive signal circuit 2 is connected to the front end of the SiC high temperature resistant gate driver integrated circuit under test to provide it with a disconnect drive voltage signal. The VOUT pin of the SiC high temperature resistant gate driver integrated circuit U1 under test outputs a low level, and the drain and source of the power MOSFET tube are not conducting. The capacitor C1 is in a discharge state, and forms a discharge circuit with the resistor R2 and the resistor R3. The voltage V4 across C1 gradually decreases and is amplified by the amplifier circuit. The voltage value is V5, and the amplification ratio is (1+R5 / R6). In the comparison circuit 6, V5 is lower than the reference voltage Vf, and the OUT pin of the comparator U3 outputs a high level. At this time, a shutdown process test is completed and will automatically switch to a turn-on process test.

[0043] The voltage data of V1, V2, V3 and V4 can be recorded in real time in the signal acquisition and recording device.

[0044] like Figure 1 and Figure 2 As shown, the present invention also provides a SiC high temperature resistant gate drive integrated circuit repeated switching test method, the test method comprising the following steps:

[0045] a. The SiC high temperature resistant gate driver integrated circuit under test is placed in a high temperature environment.

[0046] b. Set up an adjustable power supply and output three power supplies: the power supply for the effective operation of the SiC high-temperature resistant gate drive integrated circuit under test, the chip working power supply, and the reference voltage power supply.

[0047] c. The OUT pin output of the comparator U3 is high level, the diode is cut off, and the voltage at point V1 is high level, that is, the VIN pin input of the SiC high temperature resistant gate driver integrated circuit U1 under test is high level. At this time, the test circuit is in the test start-up mode, and the drive signal circuit 2 is connected to the front end of the SiC high temperature resistant gate driver integrated circuit under test to provide it with a start-up drive voltage signal.

[0048] d. When the SiC high temperature resistant gate drive integrated circuit U1 under test works normally, the VOUT pin of U1 outputs a high level, and the drain and source of the power MOSFET are turned on.

[0049] e. Capacitor C1 is in charging state, current limiting resistor R2 plays a current limiting role, and voltage V4 across C1 gradually increases, and the maximum value does not exceed the voltage value of Power+.

[0050] f. The voltage value V4 across the capacitor C1 is amplified by the circuit to a voltage value V5, and the amplification ratio is (1+R5 / R6).

[0051] g. In the comparison circuit 6, V5 exceeds the reference voltage Vf, and the OUT pin of the comparator U3 outputs a low level.

[0052] h. The OUT pin output of the comparator U3 is low level, the diode is turned on, and the voltage at point V1 is low level, that is, the VIN pin input of the SiC high temperature resistant gate driver integrated circuit U1 under test is low level. At this time, the test circuit is in the test disconnection mode, and the drive signal circuit 2 is connected to the front end of the SiC high temperature resistant gate driver integrated circuit under test to provide it with a disconnection drive voltage signal.

[0053] i. When the SiC high temperature resistant gate driver integrated circuit U1 under test is working normally, the VOUT pin of U1 outputs a low level, and the drain and source of the power MOSFET tube are not conducting.

[0054] j. Capacitor C1 is in a discharging state, and forms a discharging circuit with resistors R2 and R3. The voltage V4 across C1 gradually decreases, and the lowest voltage value does not exceed 0V.

[0055] k. The voltage value V4 across the capacitor C1 is amplified by the circuit to a voltage value V5, and the amplification ratio is (1+R5 / R6).

[0056] 1. In the comparison circuit 6, V5 is lower than the reference voltage Vf, the OUT pin of the comparator U3 outputs a high level, and the process returns to step c.

[0057] The voltage data of V1, V2, V3 and V4 can be recorded in real time in the signal acquisition and recording device.

[0058] The present invention relates the on and off process of the driving and power MOSFET tubes to the charging and discharging process of the capacitor, and realizes automatic switching of the high and low levels of the driving through a comparator. The circuit is simple and reliable, the test cycle is performed without manual participation, and the test efficiency is improved.

[0059] The present invention can realize repeated switching tests of SiC high temperature resistant gate drive integrated circuits in a range of 400° C. or even wider.

[0060] The embodiment of the present invention provides a method for designing a SiC high temperature resistant gate driver integrated circuit. The method is based on a self-excited self-oscillation circuit of a comparator. Through equipment selection and design, low voltage direct current is converted into high voltage pulse power in a high temperature environment of 200°C. By collecting the voltage signal and comparing it with the set value, the self-oscillation of the circuit is realized, thereby realizing the conversion of low voltage direct current into high voltage pulse power.

[0061] The present invention realizes repeated switching testing of SiC high-temperature resistant gate driver integrated circuits in combination with actual application scenarios, and has the advantages that the present invention has a simple circuit structure and can realize long-term stability and reliability automatic testing of product-level driver on / off functions and performance in a high-temperature environment of 400°C.

[0062] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit, characterized in that: include: Adjustable power input (1), drive signal circuit (2), power circuit (3), capacitor charging and discharging circuit (4), voltage signal amplifying circuit (5), comparison circuit (6), signal acquisition and recording interface circuit (7); The adjustable power input (1) provides a driving power supply for the driving signal circuit (2), provides a chip working power supply for the voltage signal amplifying circuit (5), the SiC high temperature resistant gate driving integrated circuit to be tested, and the comparison circuit (6), and provides a reference voltage for the comparison circuit (6); The driving signal circuit (2) provides a driving signal for the SiC high temperature resistant gate driving integrated circuit under test; The power circuit (3) receives a driving signal of the SiC high temperature resistant gate driving integrated circuit under test, the power circuit (3) is turned on when the driving signal is high, and the power circuit (3) is turned off when the driving signal is low; The capacitor charging and discharging circuit (4) charges when the power circuit (3) is turned on, and discharges when the power circuit (3) is turned off; The voltage signal amplifying circuit (5) amplifies the voltage signal output by the capacitor charging and discharging circuit (4); The comparison circuit (6) compares the voltage signal from the voltage signal amplifying circuit (5) with the reference voltage. If the voltage signal from the voltage signal amplifying circuit (5) is higher than the reference voltage, the comparison circuit (6) outputs a low level to the drive signal circuit (2). If the voltage signal from the voltage signal amplifying circuit (5) is lower than the reference voltage, the comparison circuit (6) outputs a high level to the drive signal circuit (2). The signal acquisition and recording interface circuit (7) is used to record the drive signal output by the drive signal circuit (2), the drive signal input and output by the power circuit (3), and the voltage signal input by the voltage signal amplification circuit (5).

2. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The adjustable power input (1) includes three power supplies, one of which is a driving power supply, with a positive output terminal of Power+ and a negative output terminal of GND, and has an output voltage adjustable function, and provides a driving power supply for a driving signal circuit (2); one is a chip working power supply, with a positive output terminal of VCC and a negative output terminal of GND, and provides a working power supply for a SiC high temperature resistant gate driving integrated circuit under test, a voltage signal amplifying circuit (5), and a comparison circuit (6); and one is a reference power supply, with a positive output terminal of Vf and a negative output terminal of GND, and outputs a reference voltage, which is used as a comparison reference voltage in the comparison circuit (6).

3. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The driving signal circuit (2) comprises a driving resistor R1 and a diode D1. The driving power supply output Power+ is connected to one end of the driving resistor R1. The other end of the driving resistor R1 is connected to a VIN pin of a SiC high temperature resistant gate driving integrated circuit U1 to be tested, the positive electrode of the diode D1, and the negative electrode of a voltage stabilizing diode D2 in the power circuit (3). The negative electrode of the diode D1 is connected to an OUT pin of a comparator U3 of a comparison circuit (6).

4. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The power circuit (3) comprises a voltage stabilizing diode D2 and a power MOSFET tube U2; a driving power supply output Power+ is connected to the drain of the power MOSFET tube, a gate of the power MOSFET tube is connected to the VOUT pin of the SiC high temperature resistant gate driving integrated circuit U1 to be tested, and a source of the power MOSFET tube is connected to the positive electrode of the voltage stabilizing diode D2.

5. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The capacitor charging and discharging circuit (4) comprises a current limiting resistor R2, a charging capacitor C1, and a voltage dividing resistor R3; one end of the current limiting resistor R2 is connected to the source of the power MOSFET tube of the power circuit (3), the charging capacitor C1 is connected between the other end of the current limiting resistor R2 and GND, and the voltage dividing resistor R3 is connected between the source of the power MOSFET tube of the power circuit (3) and GND.

6. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The voltage signal amplifying circuit (5) comprises an amplifier U4, a first resistor R4, a second resistor R5, a third resistor R6 and a capacitor C2, one end of the first resistor R4 is connected to the in-phase input end of the amplifier U4, and the other end of the first resistor R4 is connected between the current limiting resistor R2 and the charging capacitor C1 of the capacitor charging and discharging circuit (4); the inverting input end of the amplifier U4 is connected to the output end of the amplifier U4 through the second resistor R5, the inverting input end of the amplifier U4 is connected to GND through the third resistor R6, and the capacitor C2 is connected in parallel at both ends of the second resistor R5.

7. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The comparison circuit (6) comprises a comparator U3, wherein an IN+ pin of the comparator U3 is connected to a reference voltage output Vf of an adjustable power supply input (1), an IN- pin of the comparator U3 is connected to an output pin of an amplifier U4 of a voltage signal amplifying circuit (5), and an OUT pin of the comparator U3 is connected to a cathode of a diode D1 of a driving signal circuit (2).

8. A SiC high temperature resistant gate drive integrated circuit repeated switching test circuit as claimed in claim 1, characterized in that: The signal acquisition and recording interface circuit (7) acquires the voltage V1 between the driving resistor R1 and the diode D1, the voltage V2 of the VOUT pin of the SiC high temperature resistant gate driving integrated circuit under test, and the voltages V3 and V4 at both ends of the current limiting resistor R2.

9. A method for repeated switching test of SiC high temperature resistant gate drive integrated circuit, characterized in that: The test circuit is turned on during the working process: the driving power supply outputs Power+, the OUT pin of the comparator U3 outputs a high level, the diode D1 is cut off, and the voltage at the V1 point is a high level, that is, the VIN pin input of the SiC high temperature resistant gate drive integrated circuit U1 under test is a high level. At this time, the test circuit is in the test turn-on mode, and the driving signal circuit (2) is connected to the front end of the SiC high temperature resistant gate drive integrated circuit under test to provide it with a turn-on driving voltage signal. The VOUT pin of the SiC high temperature resistant gate drive integrated circuit U1 under test outputs a high level, and the drain and source of the power MOSFET are turned on; the capacitor C1 is in a charging state, and the current limiting resistor R2 plays a current limiting role. The voltage V4 across C1 gradually increases and is amplified by the circuit. The voltage value is V5, and the amplification ratio is (1+R5 / R6); In the comparison circuit (6), when V5 exceeds the reference voltage Vf, the OUT pin of the comparator U3 outputs a low level; at this time, a turn-on process test is completed and it will automatically switch to a turn-off process test.

10. A method for repeated switching test of SiC high temperature resistant gate drive integrated circuit, characterized in that: The shutdown working process of the test circuit: the OUT pin of the comparator U3 outputs a low level, the diode D1 is turned on, and the voltage at the point V1 is a low level, that is, the VIN pin input of the SiC high temperature resistant gate drive integrated circuit U1 under test is a low level. At this time, the test circuit is in the test shutdown mode, and the drive signal circuit (2) is connected to the front end of the SiC high temperature resistant gate drive integrated circuit under test to provide it with a disconnection drive voltage signal; the VOUT pin of the SiC high temperature resistant gate drive integrated circuit U1 under test outputs a low level, and the drain and source of the power MOSFET tube are not turned on; the capacitor C1 is in a discharge state, and forms a discharge circuit with the resistor R2 and the resistor R3. The voltage V4 across C1 gradually decreases and is amplified by the amplifier circuit. The voltage value is V5, and the amplification ratio is (1+R5 / R6); in the comparison circuit (6), V5 is lower than the reference voltage Vf, and the OUT pin of the comparator U3 outputs a high level; at this time, a shutdown process test is completed and it will automatically switch to a turn-on process test.

Images