SiC MOSFET reliability on-satellite verification test high-voltage bias device

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By designing a high-voltage bias device for verification of SiC MOSFET reliability on-satellite verification, high-voltage bias is generated using rectifier and chopping technology, the problem of SiC MOSFET reliability verification in space environment is solved, and efficient and low-cost high-voltage power supply is achieved, which meets the Application requirements of SiC MOSFET in aerospace missions.

CN119199442APending Publication Date: 2024-12-27Shanghai Institute of Basic Aerospace Technology

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Patent Information

Application Number: CN202411205117.3
Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner
Filing Date: 2024-08-30
Publication Date: 2024-12-27

AI Technical Summary

Technical Problem

The existing technology is difficult to effectively verify the reliability of SiC MOSFETs in space environments. Ground tests cannot cover the multi-factor coupling conditions in the space environment. The existing high-voltage bias system on-satellites has high power consumption and cost, which cannot meet the reliability of SiC MOSFETs. sexual verification requirements.

Method used

A high-voltage bias device for SiC MOSFET reliability on-satellite verification test is designed, including input rectification module, command module, high-voltage generation module and protection circuit module. It is powered by a star bus and uses rectification and chopping technology to generate high-voltage bias. It also realizes electrical isolation through an isolation circuit to provide reliable high-voltage power supply support.

Benefits of technology

The device is simple in composition, high reliability, flexible in modular design, and can effectively load the on-satellite reliability verification test of SiC MOSFET, meets the needs of high voltage bias and reduces the power consumption and cost of the system.

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Abstract

A SiC MOSFET reliability on-satellite verification test high-voltage bias device comprises an input rectification module, an instruction module, a high-voltage generation module and a protection circuit module. The device is simple in composition and high in reliability, the whole device adopts modular design, modules can be adjusted according to different requirements, and the system flexibility is high. The method can be applied to loading high-voltage bias in the on-satellite reliability verification test of the SiC MOSFET. Specific circuits can be realized by selecting conventional components of satellite products, and engineering realization is easy.

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Description

Technical Field

[0001] The present invention relates to the technical field of SiC MOSFET reliability testing devices, and in particular to a high-voltage bias generating device for a SiC MOSFET on-board verification test. Background Art

[0002] With the development of space missions, the requirements for miniaturization, lightweight and integration of onboard electronic systems are getting higher and higher. Compared with traditional Si-based VDMOS, SiC MOSFET has the characteristics of low characteristic on-resistance, high integration, good blocking characteristics, good thermal stability, and no tail current during the shutdown process, which reduces switching losses and thus reduces the volume of the heat sink; fast switching speed and high switching frequency are conducive to reducing the volume of inductors and capacitors in the converter, improving the power density of the device, and effectively reducing the system cost of the device. It has broad application prospects in working conditions involving high temperature, high pressure, high current, and strong radiation. However, in the space environment, the reliability research of SiC MOSFET is not sufficient. It is necessary to study the reliability and characterization parameters of SiC MOSFET in the space environment to improve its reliability and meet the needs of space applications.

[0003] SiC MOSFET devices have been used in new energy vehicles and other fields, but the incomplete standards for SiC MOSFET reliability evaluation methods limit their application and promotion in high-reliability fields such as space missions. In order to further promote the application of SiC MOSFET in space missions, it is necessary to conduct reliability evaluation and verification of SiC MOSFET. Ground reliability test is an important means of evaluating and verifying the reliability of SiC MOSFET, but ground reliability test is difficult to cover the reliability problems under the coupling of multiple factors in the space environment. Verifying the reliability of SiC MOSFET on board is an effective means to improve the reliability evaluation of SiC MOSFET and accelerate the application of SiC MOSFET on board. Reverse bias test is an important reliability test to verify the terminal reliability of power semiconductor devices. In the reverse bias test of SiC MOSFET, the drain-source bias voltage needs to reach hundreds of V or even thousands of V. The ground bias test usually uses a high-voltage power supply to provide the bias voltage. The size, weight and reliability of ground equipment are difficult to meet the application requirements on board. Although there are systems such as ion electric propulsion on board that can generate high voltage, the power consumption and cost of such systems are high, and they cannot meet the high-voltage bias requirements of the reliability verification test on board. Summary of the invention

[0004] The object of the present invention is to provide a high-voltage bias device for a SiC MOSFET reliability on-board verification test, characterized in that it comprises an input rectifier module, an instruction module, a high-voltage generating module and a protection circuit module; wherein,

[0005] The input rectifier module is powered by the on-board bus; the input rectifier module receives the voltage regulation reference signal of the instruction module, and converts the on-board bus supply voltage into the DC supply voltage required by the high-voltage generation module according to the voltage regulation reference signal;

[0006] The high-voltage generating module receives the DC power supply voltage and chops it, and implements electrical isolation between the rear-stage output and the front-stage input of the chopped voltage signal through an isolation circuit, and processes the isolated chopped voltage signal through a high-voltage rectifier circuit to obtain the high-voltage bias required for the SiC MOSFET reliability on-board verification test; and transmits the high-voltage bias required for the SiC MOSFET reliability on-board verification test to the high-voltage bias positive line;

[0007] The instruction module is connected to the on-board communication bus, receives and parses the on-board instructions, and provides a voltage regulation reference signal to the input rectifier module and a start signal to the high-voltage generating module according to the parsed results; and packages the voltage regulation reference signal status and the start signal status according to the communication protocol and sends them to the on-board communication bus.

[0008] Preferably, the input rectifier module includes a rectifier circuit and an adjustable linear voltage regulator circuit; wherein the on-board bus is connected to the rectifier circuit of the input rectifier module via a wire, and the output end of the rectifier circuit is connected to the input end of the adjustable linear voltage regulator circuit.

[0009] Preferably, the rectification circuit includes an EMI filter circuit and a DC / DC; the adjustable linear voltage regulator circuit includes an LDO and a voltage regulation reference;

[0010] The on-board bus is connected to the EMI filter of the rectifier circuit through a wire, the EMI filter output is connected to the DC / DC power input terminal, the positive line of the DC / DC power output terminal is connected to the LDO input of the adjustable linear voltage regulator circuit, and the LDO output is connected to the input positive line of the high-voltage generating module; the negative line of the DC / DC power output terminal is connected to the negative line of the high-voltage generating module input.

[0011] Preferably, the rectifier circuit includes a filter U3, a DC / DC U4, a capacitor C1 and a capacitor C2; the VIN pin of the filter U3 is connected to the positive line of the star bus, the GNDIN pin of the filter U3 is connected to the negative line of the star bus, the VO pin of the filter U3 is connected to the VIN pin of the DC / DC U4, the GNDO pin of the filter U3 is connected to the GNDIN of the DC / DC U4, the CASE end of the filter U3 is connected to the GNDC of the DC / DC U4, the VO pin of the filter U3 is connected to one end of the capacitor C1, and the GNDO pin of the filter U3 is connected to the other end of the capacitor C1; the VO of the DC / DC U4 is connected to one end of the capacitor C2, and the GNDO pin of the DC / DC U4 is connected to the other end of the capacitor C2;

[0012] The adjustable linear voltage stabilization circuit includes a linear voltage regulator U5, a resistor R1 and a capacitor C3; the IN pin of the linear voltage regulator U5 is connected to the VO pin of the DC / DC U4, one end of the resistor R1 is connected to the ADJ pin of the linear voltage regulator U5, the other end of the resistor R1 is connected to the negative input line of the high-voltage generating module, the ADJ pin of the linear voltage regulator U5 is connected to the voltage regulation reference signal, and the OUT pin of the linear voltage regulator U5 is connected to the positive input line of the high-voltage generating module; one end of the capacitor C3 is connected to the OUT end of the linear voltage regulator U5, and the other end of the capacitor C3 is connected to the GNDO of the DC / DC U4.

[0013] Preferably, the instruction module includes an MCU control circuit; the chip of the MCU control circuit is selected from any MCU control chip having GPIO, D / A port, A / D port and communication interface.

[0014] Preferably, the MCU power supply port is connected to an external +5V power supply, the MCU ground interface is connected to an external GND, and its GPIO interface is connected to an enable instruction through a port drive circuit, and the port drive circuit completes the MCU's GPIO port voltage and startup instruction voltage matching function; the MCU's D / A port is connected to a voltage regulation reference; the MCU's A / D port is connected to a voltage sampling signal; and the MCU's communication interface is connected to a lower computer through a communication bus that complies with a communication protocol.

[0015] Preferably, the protection circuit module includes a voltage isolation sampling circuit and an overvoltage protection circuit; the voltage isolation sampling circuit includes a device under test bias sampling circuit and an isolation circuit; the overvoltage protection circuit includes an overvoltage protection signal processing circuit and an overvoltage protection signal locking circuit; wherein,

[0016] The protection circuit module collects the voltage signal of the high-voltage bias positive line through the bias sampling circuit of the device under test, and isolates the collected voltage signal through the isolation circuit;

[0017] The overvoltage protection circuit converts the isolation voltage signal into an input signal of the overvoltage protection signal locking circuit through the overvoltage protection signal processing circuit. The overvoltage protection signal locking circuit triggers the switch enable instruction of the soft start circuit of the high voltage generation module according to the input signal.

[0018] Preferably, the bias sampling circuit of the device under test includes a resistor R16 and a resistor R24; one end of the resistor R16 is connected to the negative bias line of the device under test, and the other end is connected to the end of the resistor R24; the other end of the resistor R24 is connected to the high voltage side GND;

[0019] The isolation circuit includes a resistor R18, a resistor R19, a resistor R16, a resistor R27, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, an isolation amplifier U1, and a voltage regulator D6; one end of the resistor R19 is connected to one end of the resistor R16, and the other end is connected to the INP end of the isolation amplifier U1; one end of the resistor R26 is connected to the negative bias line of the device under test, and the other end is connected to the INN end of the isolation amplifier U1; one end of C11 is connected to the INP end of the isolation amplifier U1, and the other end is connected to the INN end of the isolation amplifier U1; the VDD1 end of the isolation amplifier U1 is connected to the high-voltage side +5V power supply, the GND1 end of the isolation amplifier U1 is connected to the high-voltage side GND, and the isolation The VDD2 of the operational amplifier U1 is connected to the +5V power supply on the low voltage side, the GND2 of the isolation operational amplifier U1 is connected to the GND on the low voltage side, the OUTP terminal of the isolation operational amplifier U1 is connected to one end of the resistor R18, and the OUTN terminal of the isolation operational amplifier U1 is connected to one end of the resistor R27; the other end of the resistor R18 is connected to the cathode of the voltage regulator tube D6; the other end of the resistor R27 is connected to the anode of the voltage regulator tube D6; one end of the capacitor C10 is connected to the cathode of the diode D6, and the other end is connected to the anode of the diode D6; one end of the capacitor C9 is connected to the +5V power supply on the low voltage side, and the other end is connected to the GND on the low voltage side; one end of the capacitor C8 is connected to the +5V power supply on the high voltage side, and the other end is connected to the GND on the high voltage side;

[0020] The overvoltage protection signal processing circuit includes a resistor R20, a resistor R21, a resistor R23, a resistor R30, a capacitor C5, a voltage regulator D7, and an operational amplifier U2A; the operational amplifier is LM258 of TI; one end of the resistor R21 is connected to the cathode of the voltage regulator D6, and the other end is connected to the non-inverting input end of the operational amplifier U2A; one end of the resistor R23 is connected to the anode of the voltage regulator D6, and the other end is connected to the inverting input end of the operational amplifier U2A; one end of the resistor R20 is connected to the non-inverting input end of the operational amplifier U2A, and the other end of the resistor R20 is connected to the low-voltage side GND; one end of the resistor R30 is connected to the inverting end of the operational amplifier U2A, and the other end is connected to the output end of the operational amplifier U3A; the power supply end of the operational amplifier U2A is connected to the low-voltage side +5V power supply, and the ground end of the operational amplifier U2A is connected to the low-voltage side GND; the cathode of the voltage regulator D7 is connected to the output end of the operational amplifier U2A, and the anode of the voltage regulator D7 is connected to the low-voltage side GND;

[0021] The overvoltage protection signal locking circuit includes a resistor R17, a resistor R22, a resistor R25, a resistor R28, a resistor R29, a diode D5, a voltage regulator D8, and a transistor Q2; one end of the resistor R22 is connected to the output end of the operational amplifier U2B, and the other end is connected to the in-phase input end of U2B; one end of the resistor R25 is connected to the low-voltage side +5V power supply, and the other end is connected to the inverting input end of the operational amplifier U2B; the anode of the voltage regulator D8 is connected to the low-voltage side GND, and the cathode of the voltage regulator D8 is connected to the operational amplifier U3 B inverting input terminal; one end of resistor R17 is connected to the non-inverting input terminal of operational amplifier U2B, and the other end is connected to the cathode of diode D5; the output terminal of operational amplifier U2B is connected to the output terminal of D5; one end of resistor R28 is connected to the output terminal of operational amplifier, and the other end is connected to the base of transistor Q2; one end of resistor R29 is connected to the base of transistor Q2, and the other end is connected to the low-voltage side GND; the collector of transistor Q2 is connected to the switch enable port, and the emitter of transistor Q2 is connected to the low-voltage side GND.

[0022] Preferably, the high voltage generating module comprises a soft start circuit, a pulse generating circuit, an isolation circuit and a high voltage rectifying circuit;

[0023] The pulse generating circuit receives the DC voltage signal of the adjustable linear voltage stabilizing circuit in the input rectifying module, converts the DC voltage signal into a pulse voltage signal with a fixed duty cycle, and transmits the pulse voltage signal to the isolation circuit;

[0024] The isolation circuit receives a pulse voltage signal with a fixed duty cycle, and transmits it to the high-voltage rectifier circuit after isolation and initial voltage boosting through a transformer;

[0025] The high-voltage rectifier circuit performs secondary voltage boosting and rectification on the isolated and primary voltage pulse signals to form a high-voltage DC voltage signal, which is transmitted to the bias positive line of the device under test through the high-voltage bias positive line;

[0026] The soft-start circuit receives a soft-start DC signal from the MCU control circuit, and at the same time receives a switch enable instruction from the protection circuit module, and changes the enable state of the pulse generating circuit according to the switch enable instruction.

[0027] Preferably, the pulse generating circuit comprises a pulse width modulator U6, a resistor R3, a resistor R4, a resistor R5, and a capacitor C6;

[0028] The VCC pin of the pulse width modulator U6 is connected to the positive input line of the high-voltage generating module; the VC pin of the pulse width modulator U6 is connected to the positive input line of the high-voltage generating module; the VREF pin of the pulse width modulator U6 is connected to the NI pin of the pulse width modulator U6; the CT pin of the pulse width modulator U6 is connected to the RAMP pin of the pulse width modulator U6; the VREF pin of the pulse width modulator U6 is connected to the EAOUT pin of the pulse width modulator U6; one end of the resistor R3 is connected to the RT pin of the pulse width modulator U6, and the other end of the resistor R3 is connected to the negative input line of the high-voltage generating module; one end of the capacitor C6 is connected to the CT pin of the pulse width modulator U6, and the other end of the capacitor C6 is connected to the negative input line of the high-voltage generating module; one end of the resistor R4 is connected to the OUTA pin of the pulse width modulator U6, and the other end of the resistor R4 is connected to the 1 pin of the transformer T1 of the isolation circuit; one end of the resistor R5 is connected to the OUTB pin of the pulse width modulator U6, and the other end of the resistor R5 is connected to the 2 pin of the transformer T1 of the isolation circuit;

[0029] The soft start circuit includes a capacitor C4 and a resistor R2; one end of the capacitor C4 is connected to the SS pin of the pulse width modulator U6, and the other end of the capacitor C4 is connected to the negative input line of the high voltage generating module; one end of the resistor R2 is connected to the ILIM pin of the pulse width modulator U6, and the other end of the resistor R2 is connected to the negative input line of the high voltage generating module;

[0030] The isolation circuit includes an isolation transformer; the ratio of the number of turns of the primary winding to the number of turns of the secondary winding of the isolation transformer T1 is 1:10;

[0031] The high-voltage rectifier circuit includes capacitor C12, capacitor C13, capacitor C14, capacitor C15, capacitor C16, capacitor C17, capacitor C18, capacitor C19, diode D1, diode D2, diode D3, diode D4, diode D9, diode D10, diode D11, and diode D12; one end of capacitor C12 is connected to pin 3 of isolation transformer T1, and the other end of capacitor C12 is connected to the anode of diode D1; the cathode of diode D1 is connected to pin 4 of isolation transformer T1; one end of capacitor C13 is connected to pin 4 of isolation transformer T1, and the other end of capacitor C13 is connected to the anode of diode D2; the cathode of diode D2 is connected to the anode of diode D1; one end of capacitor C14 is connected to the cathode of diode D2, and the other end of capacitor C14 is connected to the anode of diode D3; the cathode of diode D3 is connected to the anode of diode D2; one end of capacitor C15 is connected to the cathode of diode D3, and the other end of capacitor C15 is connected to the cathode of diode D3. The anode of diode D4 is connected to the cathode of diode D3; the anode of diode D4 is connected to the positive line of high voltage bias; one end of capacitor C16 is connected to pin 3 of isolation transformer T1, and the other end of capacitor C16 is connected to the cathode of diode D9; the anode of diode D1 is connected to pin 4 of isolation transformer T1; one end of capacitor C17 is connected to pin 4 of isolation transformer T1, and the other end of capacitor C17 is connected to the cathode of diode D10; the cathode of diode D9 is connected to the anode of diode D10; one end of capacitor C18 is connected to the anode of diode D10, and the other end of capacitor C18 is connected to the cathode of diode D11; the cathode of diode D11 is connected to the anode of diode D10; one end of capacitor C19 is connected to the anode of diode D11, and the other end of capacitor C19 is connected to the cathode of diode D12; the cathode of diode D11 is connected to the anode of diode D12; the cathode of diode D12 is connected to the negative line of high voltage bias.

[0032] The beneficial effects of the present invention include:

[0033] The purpose of the present invention is to provide a design of a high-voltage bias device for a SiC MOSFET reliability on-board verification test. The device consists of an input rectifier module, a command module, a high-voltage generating module and a protection circuit module. The device has a simple composition and high reliability. The overall modular design allows the modules to be adjusted according to different needs, and the system has high flexibility. It can be used to load high-voltage bias in the SiC MOSFET on-board reliability verification test. The specific circuit implementation can use conventional components of on-board products, which is easy to implement in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of a high voltage bias device for the on-board verification test of SiC MOSFET reliability according to the present invention;

[0035] Figure 2a This is a schematic diagram of the input rectifier module of the high-voltage bias device of the SiC MOSFET reliability on-board verification test of the present invention;

[0036] Figure 2b This is a schematic diagram of the MCU control circuit of the high-voltage bias device of the SiC MOSFET reliability on-board verification test of the present invention;

[0037] Figure 2c It is a voltage isolation sampling circuit and an overvoltage protection circuit of a high-voltage bias device for a SiC MOSFET reliability on-board verification test of the present invention;

[0038] Figure 3 Schematic diagram of the high voltage bias device of the SiC MOSFET reliability on-board verification test in the present invention, the rectifier circuit level adjustable linear voltage regulator circuit

[0039] Figure 4 Schematic diagram of the MCU control circuit of the high-voltage bias device for the on-board verification test of the SiC MOSFET reliability of the present invention

[0040] Figure 5 This is a schematic diagram of a voltage isolation sampling circuit and an overvoltage protection circuit of a high-voltage bias device for a SiC MOSFET reliability on-board verification test of the present invention;

[0041] Figure 6 This is a schematic diagram of a high-voltage generating module of a high-voltage bias device for an on-board verification test of SiC MOSFET reliability in the present invention. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0043] The present invention is further described below in conjunction with the accompanying drawings:

[0044] like Figure 1 Figure 1 shows a schematic diagram of a high voltage bias device for the onboard reliability verification test of SiC MOSFET. The device includes an input rectifier module, a command module, a high voltage generation module, and a protection circuit module.

[0045] The input rectifier module is powered by the on-board bus; the input rectifier module receives the voltage regulation reference signal of the instruction module, and converts the on-board bus supply voltage into the DC supply voltage required by the high-voltage generation module according to the voltage regulation reference signal;

[0046] The high-voltage generating module receives the DC power supply voltage and chops it, and implements electrical isolation between the rear-stage output and the front-stage input of the chopped voltage signal through an isolation circuit, and processes the isolated chopped voltage signal through a high-voltage rectifier circuit to obtain the high-voltage bias required for the SiC MOSFET reliability on-board verification test; and transmits the high-voltage bias required for the SiC MOSFET reliability on-board verification test to the high-voltage bias positive line;

[0047] The instruction module is connected to the on-board communication bus, receives and parses the on-board instructions, and provides a voltage regulation reference signal to the input rectifier module and a start signal to the high-voltage generating module according to the parsed results; and packages the voltage regulation reference signal status and the start signal status according to the communication protocol and sends them to the on-board communication bus.

[0048] like Figure 2a As shown, the input rectifier module includes a rectifier circuit and an adjustable linear voltage regulator circuit; the on-board bus is connected to the rectifier circuit of the input rectifier module through a wire, and the output end of the rectifier circuit is connected to the input end of the adjustable linear voltage regulator circuit.

[0049] The rectifier circuit includes an EMI filter circuit and a DC / DC; the adjustable linear voltage regulator circuit includes an LDO and a voltage regulation reference;

[0050] The on-board bus is connected to the EMI filter of the rectifier circuit through a wire, the EMI filter output is connected to the DC / DC power input terminal, the positive line of the DC / DC power output terminal is connected to the LDO input of the adjustable linear voltage regulator circuit, and the LDO output is connected to the input positive line of the high-voltage generating module; the negative line of the DC / DC power output terminal is connected to the negative line of the high-voltage generating module input.

[0051] The specific implementation circuit is as follows Figure 3As shown, the rectifier circuit includes a filter U3, a DC / DC U4, a capacitor C1 and a capacitor C2. The filter U3 selects LFCE / (20-50)-461-150 of Xi'an Microelectronics Research Institute, the VIN pin of the filter U3 is connected to the positive line of the star bus, the GNDIN pin of the filter U3 is connected to the negative line of the star bus, the VO pin of the filter U3 is connected to the VIN pin of the DC / DC U4, the GNDO pin of the filter U3 is connected to the GNDIN of the DC / DC U4, the CASE end of the filter U3 is connected to the GNDC of the DC / DC U4, the VO pin of the filter U3 is connected to one end of the capacitor C1, and the GNDO pin of the filter U3 is connected to the other end of the capacitor C1; the VO of the DC / DC U4 is connected to one end of the capacitor C2, and the GNDO pin of the DC / DC U4 is connected to the other end of the capacitor C2; the adjustable linear voltage regulator circuit is composed of a linear regulator U5, a resistor R1 and a capacitor C3. The IN pin of the linear regulator U5 is connected to the VO pin of the DC / DC U4, one end of the resistor R1 is connected to the ADJ pin of the linear regulator U5, the other end of the resistor R1 is connected to the negative input line of the high-voltage generating module, the ADJ pin of the linear regulator U5 is connected to the voltage regulation reference signal, and the OUT pin of the linear regulator U5 is connected to the positive input line of the high-voltage generating module; one end of the capacitor C3 is connected to the OUT end of the linear regulator U5, and the other end of the capacitor C3 is connected to the GNDO of the DC / DC U4.

[0052] The instruction module includes an MCU control circuit. Figure 2b As shown, the MCU serves as a control node, the communication interface of the instruction module is connected to an external lower computer through a communication bus, receives relevant startup instructions sent by the lower computer through the communication bus, and sends the bias voltage sampling signal to the lower computer through the communication bus.

[0053] The specific implementation circuit is as follows Figure 4 As shown, the MCU control circuit can select any MCU control chip with GPIO, D / A port, A / D port and communication interface. The MCU power supply port is connected to the external +5V power supply, the MCU ground interface is connected to the external GND, and its GPIO interface is connected to the enable instruction through the port drive circuit. The port drive circuit completes the MCU GPIO port voltage and the start instruction voltage matching function; the MCU's D / A port is connected to the voltage regulation reference; the MCU's A / D port is connected to the voltage sampling signal; the MCU's communication interface is connected to the lower computer through a communication bus that complies with the communication protocol.

[0054] The protection circuit module includes a voltage isolation sampling circuit and an overvoltage protection circuit.

[0055] like Figure 2cAs shown, the protection circuit module includes a voltage isolation sampling circuit and an overvoltage protection circuit; the voltage isolation sampling circuit includes a test device bias sampling circuit and an isolation circuit; the overvoltage protection circuit includes an overvoltage protection signal processing circuit and an overvoltage protection signal locking circuit; wherein,

[0056] The protection circuit module collects the voltage signal of the high-voltage bias positive line through the bias sampling circuit of the device under test, and isolates the collected voltage signal through the isolation circuit;

[0057] The overvoltage protection circuit converts the isolation voltage signal into an input signal of the overvoltage protection signal locking circuit through the overvoltage protection signal processing circuit. The overvoltage protection signal locking circuit triggers the switch enable instruction of the soft start circuit of the high voltage generation module according to the input signal.

[0058] The specific implementation circuit is as follows Figure 5 As shown, the bias sampling circuit of the device under test is composed of a resistor R16 and a resistor R24. One end of the resistor R16 is connected to the negative bias line of the device under test, and the other end is connected to the end of the resistor R24. The other end of the resistor R24 is connected to the high voltage side GND.

[0059] The isolation circuit is composed of resistor R18, resistor R19, resistor R16, resistor R27, capacitor C8, capacitor C9, capacitor C10, capacitor C11, isolation amplifier U1, and voltage regulator D6. The isolation amplifier U1 uses TI's AMC1300B, and the voltage regulator D6 uses a voltage regulator with a voltage regulation point of 5.5V. One end of resistor R19 is connected to one end of resistor R16, and the other end is connected to the INP end of the isolation amplifier U1; one end of resistor R26 is connected to the negative bias line of the test device, and the other end is connected to the INN end of the isolation amplifier U1; one end of C11 is connected to the INP end of the isolation amplifier U1, and the other end is connected to the INN end of the isolation amplifier U1; the VDD1 end of the isolation amplifier U1 is connected to the +5V power supply on the high-voltage side, the GND1 end of the isolation amplifier U1 is connected to the GND on the high-voltage side, and the VDD2 of the isolation amplifier U1 is connected to the +5V power supply on the low-voltage side. Electrical connection, GND2 of the isolation amplifier U1 is connected to the low-voltage side GND, the OUTP end of the isolation amplifier U1 is connected to one end of the resistor R18, and the OUTN end of the isolation amplifier U1 is connected to one end of the resistor R27; the other end of the resistor R18 is connected to the cathode of the voltage regulator tube D6; the other end of the resistor R27 is connected to the anode of the voltage regulator tube D6; one end of the capacitor C10 is connected to the cathode of the diode D6, and the other end is connected to the anode of the diode D6; one end of the capacitor C9 is connected to the low-voltage side +5V power supply, and the other end is connected to the low-voltage side GND. One end of the capacitor C8 is connected to the high-voltage side +5V power supply, and the other end is connected to the high-voltage side GND;

[0060] The overvoltage protection signal processing circuit is composed of resistor R20, resistor R21, resistor R23, resistor R30, capacitor C5, voltage regulator tube D7, and operational amplifier U2A. The operational amplifier is LM258 from TI. One end of the resistor R21 is connected to the cathode of the voltage regulator tube D6, and the other end is connected to the non-inverting input terminal of the operational amplifier U2A; one end of the resistor R23 is connected to the anode of the voltage regulator tube D6, and the other end is connected to the inverting input terminal of the operational amplifier U2A; one end of the resistor R20 is connected to the non-inverting input terminal of the operational amplifier U2A, and the other end of the resistor R20 is connected to the low-voltage side GND; one end of the resistor R30 is connected to the inverting terminal of the operational amplifier U2A, and the other end is connected to the output terminal of the operational amplifier U3A; the power supply terminal of the operational amplifier U2A is connected to the low-voltage side +5V power supply, and the ground terminal of the operational amplifier U2A is connected to the low-voltage side GND; the cathode of the voltage regulator tube D7 is connected to the output terminal of the operational amplifier U2A, and the anode of the voltage regulator tube D7 is connected to the low-voltage side GND.

[0061] The overvoltage protection signal locking circuit is composed of a resistor R17, a resistor R22, a resistor R25, a resistor R28, a resistor R29, a diode D5, a voltage regulator D8, and a transistor Q2. One end of the resistor R22 is connected to the output end of the operational amplifier U2B, and the other end is connected to the non-inverting input end of U2B; one end of the resistor R25 is connected to the low-voltage side +5V power supply, and the other end is connected to the inverting input end of the operational amplifier U2B; the anode of the voltage regulator D8 is connected to the low-voltage side GND, and the cathode of the voltage regulator D8 is connected to the inverting input end of the operational amplifier U3B; one end of the resistor R17 is connected to the non-inverting input end of the operational amplifier U2B, and the other end is connected to the cathode of the diode D5; the output end of the operational amplifier U2B is connected to the output end of D5; one end of the resistor R28 is connected to the output end of the operational amplifier, and the other end is connected to the base of the transistor Q2; one end of the resistor R29 is connected to the base of the transistor Q2, and the other end is connected to the low-voltage side GND; the collector of the transistor Q2 is connected to the switch enable port, and the emitter of the transistor Q2 is connected to the low-voltage side GND.

[0062] The high voltage generating module includes a soft start circuit, a pulse generating circuit, an isolation circuit and a high voltage rectifying circuit;

[0063] The pulse generating circuit receives the DC voltage signal of the adjustable linear voltage stabilizing circuit in the input rectifying module, converts the DC voltage signal into a pulse voltage signal with a fixed duty cycle, and transmits the pulse voltage signal to the isolation circuit;

[0064] The isolation circuit receives a pulse voltage signal with a fixed duty cycle, and transmits it to the high-voltage rectifier circuit after isolation and initial voltage boosting through a transformer;

[0065] The high-voltage rectifier circuit performs secondary voltage boosting and rectification on the isolated and primary voltage pulse signals to form a high-voltage DC voltage signal, which is transmitted to the bias positive line of the device under test through the high-voltage bias positive line;

[0066] The soft-start circuit receives a soft-start DC signal from the MCU control circuit, and at the same time receives a switch enable instruction from the protection circuit module, and changes the enable state of the pulse generating circuit according to the switch enable instruction.

[0067] like Figure 6 As shown, the pulse generating circuit mainly consists of a pulse width modulator U6, a resistor R3, a resistor R4, a resistor R5, and a capacitor C6. The pulse width modulator U6 is UC1825 produced by TI. The VCC pin of the pulse width modulator U6 is connected to the positive input line of the high-voltage generating module; the VC pin of the pulse width modulator U6 is connected to the positive input line of the high-voltage generating module; the VREF pin of the pulse width modulator U6 is connected to the NI pin of the pulse width modulator U6; the CT pin of the pulse width modulator U6 is connected to the RAMP pin of the pulse width modulator U6; the VREF pin of the pulse width modulator U6 is connected to the EAOUT pin of the pulse width modulator U6; one end of the resistor R3 is connected to the RT pin of the pulse width modulator U6, and the other end of the resistor R3 is connected to the negative input line of the high-voltage generating module; one end of the capacitor C6 is connected to the CT pin of the pulse width modulator U6, and the other end of the capacitor C6 is connected to the negative input line of the high-voltage generating module; one end of the resistor R4 is connected to the OUTA pin of the pulse width modulator U6, and the other end of the resistor R4 is connected to the 1 pin of the transformer T1 of the isolation circuit; one end of the resistor R5 is connected to the OUTB pin of the pulse width modulator U6, and the other end of the resistor R5 is connected to the 2 pin of the transformer T1 of the isolation circuit.

[0068] The soft start circuit is composed of capacitor C4 and resistor R2. One end of capacitor C4 is connected to the SS pin of pulse width modulator U6, and the other end of capacitor C4 is connected to the negative input line of high voltage generator module; one end of resistor R2 is connected to the ILIM pin of pulse width modulator U6, and the other end of resistor R2 is connected to the negative input line of high voltage generator module.

[0069] The isolation circuit is composed of an isolation transformer. The ratio of the number of turns of the primary winding to the number of turns of the secondary winding of the isolation transformer T1 is 1:10.

[0070] The high voltage rectifier circuit is composed of capacitor C12, capacitor C13, capacitor C14, capacitor C15, capacitor C16, capacitor C17, capacitor C18, capacitor C19, diode D1, diode D2, diode D3, diode D4, diode D9, diode D10, diode D11 and diode D12. One end of capacitor C12 is connected to pin 3 of isolation transformer T1, and the other end of capacitor C12 is connected to the anode of diode D1; the cathode of diode D1 is connected to pin 4 of isolation transformer T1; one end of capacitor C13 is connected to pin 4 of isolation transformer T1, and the other end of capacitor C13 is connected to the anode of diode D2; the cathode of diode D2 is connected to the anode of diode D1; one end of capacitor C14 is connected to the cathode of diode D2, and the other end of capacitor C14 is connected to the anode of diode D3; the cathode of diode D3 is connected to the anode of diode D2; one end of capacitor C15 is connected to the cathode of diode D3, and the other end of capacitor C15 is connected to the anode of diode D4; the cathode of diode D4 is connected to the anode of diode D3; the anode of diode D4 is connected to the high voltage bias positive line. One end of capacitor C16 is connected to pin 3 of isolation transformer T1, and the other end of capacitor C16 is connected to the cathode of diode D9; the anode of diode D1 is connected to pin 4 of isolation transformer T1; one end of capacitor C17 is connected to pin 4 of isolation transformer T1, and the other end of capacitor C17 is connected to the cathode of diode D10; the cathode of diode D9 is connected to the anode of diode D10; one end of capacitor C18 is connected to the anode of diode D10, and the other end of capacitor C18 is connected to the cathode of diode D11; the cathode of diode D11 is connected to the anode of diode D10; one end of capacitor C19 is connected to the anode of diode D11, and the other end of capacitor C19 is connected to the cathode of diode D12; the cathode of diode D11 is connected to the anode of diode D12; the cathode of diode D12 is connected to the negative line of high voltage bias.

[0071] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A high voltage bias device for a SiC MOSFET reliability on-board verification test, characterized in that: It includes an input rectifier module, an instruction module, a high voltage generation module and a protection circuit module; wherein, The input rectifier module is powered by the on-board bus; the input rectifier module receives the voltage regulation reference signal of the instruction module, and converts the on-board bus supply voltage into the DC supply voltage required by the high-voltage generation module according to the voltage regulation reference signal; The high-voltage generating module receives the DC power supply voltage and chops it, and implements electrical isolation between the rear-stage output and the front-stage input of the chopped voltage signal through an isolation circuit, and processes the isolated chopped voltage signal through a high-voltage rectifier circuit to obtain the high-voltage bias required for the SiC MOSFET reliability on-board verification test; and transmits the high-voltage bias required for the SiC MOSFET reliability on-board verification test to the high-voltage bias positive line; The instruction module is connected to the on-board communication bus, receives and parses the on-board instructions, and provides a voltage regulation reference signal to the input rectifier module and a start signal to the high-voltage generating module according to the parsed results; and packages the voltage regulation reference signal status and the start signal status according to the communication protocol and sends them to the on-board communication bus.

2. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 1, characterized in that: The input rectifier module includes a rectifier circuit and an adjustable linear voltage regulator circuit; wherein the on-board bus is connected to the rectifier circuit of the input rectifier module via a wire, and the output end of the rectifier circuit is connected to the input end of the adjustable linear voltage regulator circuit.

3. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 2, characterized in that: The rectifier circuit includes an EMI filter circuit and a DC / DC; the adjustable linear voltage regulator circuit includes an LDO and a voltage regulation reference; The on-board bus is connected to the EMI filter of the rectifier circuit through a wire, the EMI filter output is connected to the DC / DC power input terminal, the positive line of the DC / DC power output terminal is connected to the LDO input of the adjustable linear voltage regulator circuit, and the LDO output is connected to the input positive line of the high-voltage generation module; The negative line of the DC / DC power output terminal is connected to the negative line of the high voltage generating module input.

4. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 3, characterized in that: The rectifier circuit includes a filter U3, a DC / DC U4, a capacitor C1 and a capacitor C2; the VIN pin of the filter U3 is connected to the positive line of the star bus, the GNDIN pin of the filter U3 is connected to the negative line of the star bus, the VO pin of the filter U3 is connected to the VIN pin of the DC / DC U4, the GNDO pin of the filter U3 is connected to the GNDIN of the DC / DC U4, the CASE end of the filter U3 is connected to the GNDC of the DC / DC U4, the VO pin of the filter U3 is connected to one end of the capacitor C1, and the GNDO pin of the filter U3 is connected to the other end of the capacitor C1; the VO of the DC / DC U4 is connected to one end of the capacitor C2, and the GNDO pin of the DC / DC U4 is connected to the other end of the capacitor C2; The adjustable linear voltage stabilization circuit includes a linear voltage regulator U5, a resistor R1 and a capacitor C3; the IN pin of the linear voltage regulator U5 is connected to the VO pin of the DC / DC U4, one end of the resistor R1 is connected to the ADJ pin of the linear voltage regulator U5, the other end of the resistor R1 is connected to the negative input line of the high-voltage generating module, the ADJ pin of the linear voltage regulator U5 is connected to the voltage regulation reference signal, and the OUT pin of the linear voltage regulator U5 is connected to the positive input line of the high-voltage generating module; one end of the capacitor C3 is connected to the OUT end of the linear voltage regulator U5, and the other end of the capacitor C3 is connected to the GNDO of the DC / DC U4.

5. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 1, characterized in that: The instruction module includes an MCU control circuit; the chip of the MCU control circuit is selected from any MCU control chip with GPIO, D / A port, A / D port and communication interface.

6. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 5, characterized in that: The MCU power supply port is connected to the external +5V power supply, the MCU ground interface is connected to the external GND, and its GPIO interface is connected to the enable instruction through the port drive circuit. The port drive circuit completes the matching function between the MCU's GPIO port voltage and the startup instruction voltage; the MCU's D / A port is connected to the voltage regulation reference; the MCU's A / D port is connected to the voltage sampling signal; the MCU's communication interface is connected to the lower computer through a communication bus that conforms to the communication protocol.

7. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 1, characterized in that: The protection circuit module includes a voltage isolation sampling circuit and an overvoltage protection circuit; the voltage isolation sampling circuit includes a test device bias sampling circuit and an isolation circuit; the overvoltage protection circuit includes an overvoltage protection signal processing circuit and an overvoltage protection signal locking circuit; wherein, The protection circuit module collects the voltage signal of the high-voltage bias positive line through the bias sampling circuit of the device under test, and isolates the collected voltage signal through the isolation circuit; The overvoltage protection circuit converts the isolation voltage signal into an input signal of the overvoltage protection signal locking circuit through the overvoltage protection signal processing circuit. The overvoltage protection signal locking circuit triggers the switch enable instruction of the soft start circuit of the high voltage generation module according to the input signal.

8. The high voltage bias device for the on-board verification test of SiC MOSFET reliability according to claim 5, characterized in that: The device under test bias sampling circuit comprises a resistor R16 and a resistor R24; one end of the resistor R16 is connected to the negative bias line of the device under test, and the other end is connected to the end of the resistor R24; the other end of the resistor R24 is connected to the high voltage side GND; The isolation circuit includes a resistor R18, a resistor R19, a resistor R16, a resistor R27, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, an isolation amplifier U1, and a voltage regulator D6; one end of the resistor R19 is connected to one end of the resistor R16, and the other end is connected to the INP end of the isolation amplifier U1; one end of the resistor R26 is connected to the negative bias line of the device under test, and the other end is connected to the INN end of the isolation amplifier U1; one end of C11 is connected to the INP end of the isolation amplifier U1, and the other end is connected to the INN end of the isolation amplifier U1; the VDD1 end of the isolation amplifier U1 is connected to the high-voltage side +5V power supply, the GND1 end of the isolation amplifier U1 is connected to the high-voltage side GND, and the isolation The VDD2 of the operational amplifier U1 is connected to the +5V power supply on the low voltage side, the GND2 of the isolation operational amplifier U1 is connected to the GND on the low voltage side, the OUTP terminal of the isolation operational amplifier U1 is connected to one end of the resistor R18, and the OUTN terminal of the isolation operational amplifier U1 is connected to one end of the resistor R27; the other end of the resistor R18 is connected to the cathode of the voltage regulator tube D6; the other end of the resistor R27 is connected to the anode of the voltage regulator tube D6; one end of the capacitor C10 is connected to the cathode of the diode D6, and the other end is connected to the anode of the diode D6; one end of the capacitor C9 is connected to the +5V power supply on the low voltage side, and the other end is connected to the GND on the low voltage side; one end of the capacitor C8 is connected to the +5V power supply on the high voltage side, and the other end is connected to the GND on the high voltage side; The overvoltage protection signal processing circuit includes a resistor R20, a resistor R21, a resistor R23, a resistor R30, a capacitor C5, a voltage regulator D7, and an operational amplifier U2A; the operational amplifier is LM258 of TI; one end of the resistor R21 is connected to the cathode of the voltage regulator D6, and the other end is connected to the non-inverting input end of the operational amplifier U2A; one end of the resistor R23 is connected to the anode of the voltage regulator D6, and the other end is connected to the inverting input end of the operational amplifier U2A; one end of the resistor R20 is connected to the non-inverting input end of the operational amplifier U2A, and the other end of the resistor R20 is connected to the low-voltage side GND; one end of the resistor R30 is connected to the inverting end of the operational amplifier U2A, and the other end is connected to the output end of the operational amplifier U3A; the power supply end of the operational amplifier U2A is connected to the low-voltage side +5V power supply, and the ground end of the operational amplifier U2A is connected to the low-voltage side GND; the cathode of the voltage regulator D7 is connected to the output end of the operational amplifier U2A, and the anode of the voltage regulator D7 is connected to the low-voltage side GND; The overvoltage protection signal locking circuit includes a resistor R17, a resistor R22, a resistor R25, a resistor R28, a resistor R29, a diode D5, a voltage regulator D8, and a transistor Q2; one end of the resistor R22 is connected to the output end of the operational amplifier U2B, and the other end is connected to the in-phase input end of U2B; one end of the resistor R25 is connected to the low-voltage side +5V power supply, and the other end is connected to the inverting input end of the operational amplifier U2B; the anode of the voltage regulator D8 is connected to the low-voltage side GND, and the cathode of the voltage regulator D8 is connected to the operational amplifier U3 B inverting input terminal; one end of resistor R17 is connected to the non-inverting input terminal of operational amplifier U2B, and the other end is connected to the cathode of diode D5; the output terminal of operational amplifier U2B is connected to the output terminal of D5; one end of resistor R28 is connected to the output terminal of operational amplifier, and the other end is connected to the base of transistor Q2; one end of resistor R29 is connected to the base of transistor Q2, and the other end is connected to the low-voltage side GND; the collector of transistor Q2 is connected to the switch enable port, and the emitter of transistor Q2 is connected to the low-voltage side GND.

9. The high voltage bias device for onboard verification test of SiC MOSFET reliability according to claim 1, characterized in that: The high voltage generating module includes a soft start circuit, a pulse generating circuit, an isolation circuit and a high voltage rectifying circuit; The pulse generating circuit receives the DC voltage signal of the adjustable linear voltage stabilizing circuit in the input rectifying module, converts the DC voltage signal into a pulse voltage signal with a fixed duty cycle, and transmits the pulse voltage signal to the isolation circuit; The isolation circuit receives a pulse voltage signal with a fixed duty cycle, and transmits it to the high-voltage rectifier circuit after isolation and initial voltage boosting through a transformer; The high-voltage rectifier circuit performs secondary voltage boosting and rectification on the isolated and primary voltage pulse signals to form a high-voltage DC voltage signal, which is transmitted to the bias positive line of the device under test through the high-voltage bias positive line; The soft-start circuit receives a soft-start DC signal from the MCU control circuit, and at the same time receives a switch enable instruction from the protection circuit module, and changes the enable state of the pulse generating circuit according to the switch enable instruction.

10. The high voltage bias device for onboard verification test of SiC MOSFET reliability according to claim 9, characterized in that: The pulse generating circuit includes a pulse width modulator U6, a resistor R3, a resistor R4, a resistor R5, and a capacitor C6; The VCC pin of the pulse width modulator U6 is connected to the positive input line of the high-voltage generating module; the VC pin of the pulse width modulator U6 is connected to the positive input line of the high-voltage generating module; the VREF pin of the pulse width modulator U6 is connected to the NI pin of the pulse width modulator U6; the CT pin of the pulse width modulator U6 is connected to the RAMP pin of the pulse width modulator U6; the VREF pin of the pulse width modulator U6 is connected to the EAOUT pin of the pulse width modulator U6; one end of the resistor R3 is connected to the RT pin of the pulse width modulator U6, and the other end of the resistor R3 is connected to the negative input line of the high-voltage generating module; one end of the capacitor C6 is connected to the CT pin of the pulse width modulator U6, and the other end of the capacitor C6 is connected to the negative input line of the high-voltage generating module; one end of the resistor R4 is connected to the OUTA pin of the pulse width modulator U6, and the other end of the resistor R4 is connected to the 1 pin of the transformer T1 of the isolation circuit; one end of the resistor R5 is connected to the OUTB pin of the pulse width modulator U6, and the other end of the resistor R5 is connected to the 2 pin of the transformer T1 of the isolation circuit; The soft start circuit includes a capacitor C4 and a resistor R2; one end of the capacitor C4 is connected to the SS pin of the pulse width modulator U6, and the other end of the capacitor C4 is connected to the negative input line of the high voltage generating module; one end of the resistor R2 is connected to the ILIM pin of the pulse width modulator U6, and the other end of the resistor R2 is connected to the negative input line of the high voltage generating module; The isolation circuit includes an isolation transformer; the ratio of the number of turns of the primary winding to the number of turns of the secondary winding of the isolation transformer T1 is 1:10; The high-voltage rectifier circuit includes capacitor C12, capacitor C13, capacitor C14, capacitor C15, capacitor C16, capacitor C17, capacitor C18, capacitor C19, diode D1, diode D2, diode D3, diode D4, diode D9, diode D10, diode D11, and diode D12; one end of capacitor C12 is connected to pin 3 of isolation transformer T1, and the other end of capacitor C12 is connected to the anode of diode D1; the cathode of diode D1 is connected to pin 4 of isolation transformer T1; one end of capacitor C13 is connected to pin 4 of isolation transformer T1, and the other end of capacitor C13 is connected to the anode of diode D2; the cathode of diode D2 is connected to the anode of diode D1; one end of capacitor C14 is connected to the cathode of diode D2, and the other end of capacitor C14 is connected to the anode of diode D3; the cathode of diode D3 is connected to the anode of diode D2; one end of capacitor C15 is connected to the cathode of diode D3, and the other end of capacitor C15 is connected to the cathode of diode D3. The anode of diode D4 is connected to the cathode of diode D3; the anode of diode D4 is connected to the positive line of high voltage bias; one end of capacitor C16 is connected to pin 3 of isolation transformer T1, and the other end of capacitor C16 is connected to the cathode of diode D9; the anode of diode D1 is connected to pin 4 of isolation transformer T1; one end of capacitor C17 is connected to pin 4 of isolation transformer T1, and the other end of capacitor C17 is connected to the cathode of diode D10; the cathode of diode D9 is connected to the anode of diode D10; one end of capacitor C18 is connected to the anode of diode D10, and the other end of capacitor C18 is connected to the cathode of diode D11; the cathode of diode D11 is connected to the anode of diode D10; one end of capacitor C19 is connected to the anode of diode D11, and the other end of capacitor C19 is connected to the cathode of diode D12; the cathode of diode D11 is connected to the anode of diode D12; the cathode of diode D12 is connected to the negative line of high voltage bias.