Intelligent power module overcurrent protection threshold test circuit and test method

Abstract

The invention relates to the technical field of intelligent power modules, and provides an intelligent power module overcurrent protection threshold test circuit and a test method, which are used for testing an intelligent power module. Comprising a first power supply, a first signal generator, a second signal generator, a second power supply, a first isolation power supply, a second isolation power supply, a third isolation power supply, a plurality of power supplies, a plurality of ampere meters and a first resistor, a first end of the first power supply is connected with a VCC port of the intelligent power module, a second end of the first power supply is connected with a grounding end of the intelligent power module, a first end of the first signal generator is connected with an HIN port of the intelligent power module, and a second end of the first signal generator is grounded; the first end of the second signal generator is connected with the ITRIP port of the intelligent power module, and the second end of the second signal generator is grounded. The intelligent power module overcurrent protection threshold test circuit is good in test effect and high in product percent of pass.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent power modules, and in particular to an intelligent power module overcurrent protection threshold test circuit and a test method. Background Art

[0002] Intelligent Power Module, or IPM (Intelligent Power Module), is a power drive product that combines power electronics and integrated circuit technology. The intelligent power module integrates power switching devices and high-voltage drive circuits, and has built-in fault detection circuits such as overvoltage, overcurrent and overheating. On the one hand, the intelligent power module receives the control signal of the MCU to drive the subsequent circuit to work, and on the other hand, it sends the system status detection signal back to the MCU. Compared with traditional discrete solutions, the intelligent power module has won an increasingly large market with its advantages such as high integration and high reliability. It is especially suitable for frequency converters and various inverter power supplies that drive motors. It is an ideal power electronic device for variable frequency speed regulation, metallurgical machinery, electric traction, servo drive, and variable frequency home appliances.

[0003] With the rapid development of industry, IPM intelligent power modules are widely used in various fields. The overcurrent protection function of IPM intelligent power modules is very important: if the IPM has an overcurrent (the current value flowing through the IGBT) that exceeds the overcurrent action current and the time exceeds toff, overcurrent protection occurs, the gate drive circuit is blocked, and a fault signal is output. If the load is short-circuited or the control system fails and causes a short circuit, and the current value flowing through the IGBT exceeds the short-circuit action current, short-circuit protection occurs immediately, the gate drive circuit is blocked, and a fault signal is output.

[0004] Therefore, when the IPM intelligent power module is produced off the production line, its overcurrent protection threshold voltage must be tested to see if it meets the standard. Summary of the invention

[0005] The present invention provides an intelligent power module overcurrent protection threshold test circuit and test method, aiming to solve the problems of poor test effect and poor pass rate of existing intelligent power modules under different currents.

[0006] An embodiment of the present invention provides an intelligent power module overcurrent protection threshold test circuit for testing an intelligent power module, comprising: a first power supply, a first signal generator, a second signal generator, a second power supply, a first isolated power supply, a second isolated power supply, a third isolated power supply, multiple power supplies, multiple ammeters, and a first resistor;

[0007] A first end of the first power supply is connected to a VCC port of the intelligent power module, a second end of the first power supply is connected to a ground terminal of the intelligent power module, a first end of the first signal generator is connected to a HIN port of the intelligent power module, and a second end of the first signal generator is grounded;

[0008] The first end of the second signal generator is connected to the ITRIP port of the intelligent power module, the second end of the second signal generator is grounded, the first end of the first resistor is connected to the FLTEN port of the intelligent power module, the second end of the first resistor is connected to the first end of the second power supply, and the second end of the second power supply is grounded;

[0009] The first end of the first isolated power supply is connected to the VB1 port of the intelligent power module, the first end of the second isolated power supply is connected to the VB2 port of the intelligent power module, the first end of the third isolated power supply is connected to the VB3 port of the intelligent power module, the second end of the first isolated power supply, the second end of the second isolated power supply and the second end of the third isolated power supply are respectively connected to the first ends of multiple power supplies, the second ends of the multiple power supplies are connected to the first ends of multiple ammeters, and the second ends of the multiple ammeters are connected to the bridge arm circuit of the intelligent power module to implement testing of the bridge arm circuit.

[0010] Preferably, the bridge arm circuit includes an upper bridge arm circuit and a lower bridge arm circuit, and the upper bridge arm circuit is connected to the lower bridge arm circuit; the first ends of multiple power supplies are connected to the first end of the upper bridge arm circuit or the lower bridge arm circuit, and the second ends of multiple ammeters are connected to the second end of the upper bridge arm circuit or the lower bridge arm circuit.

[0011] Preferably, the upper bridge arm circuit includes a first transistor, a second transistor and a third transistor; the lower bridge arm circuit includes a fourth transistor, a fifth transistor and a sixth transistor;

[0012] The source of the first transistor is connected to the drain of the fourth transistor, the gate of the first transistor is connected to the HO1 port of the HVIC chip of the intelligent power module, the gate of the fourth transistor is connected to the LO1 port of the HVIC chip, and the drain of the first transistor is respectively connected to the drain of the second transistor and the drain of the third transistor; the gate of the second transistor is connected to the HO3 port of the HVC chip, the source of the second transistor is connected to the VS2 port of the HVIC chip and the drain of the fifth transistor, the source of the fourth transistor, the source of the fifth transistor and the source of the sixth transistor are grounded; the gate of the fifth transistor is connected to the LO2 port of the HVIC chip, and the gate of the sixth transistor is connected to the LO3 port of the HVIC chip; the gate of the third transistor is connected to the HO3 port of the HVIC chip, and the source of the third transistor is connected to the drain of the sixth transistor.

[0013] Preferably, the plurality of power supplies include a first power supply, a second power supply and a third power supply, and the plurality of ammeters include a first ammeter, a second ammeter and a third ammeter; one end of the first power supply, the second power supply and the third power supply are respectively connected in series with one end of the first ammeter, the second ammeter and the third ammeter;

[0014] When testing the upper bridge arm circuit, the other ends of the first power supply, the second power supply and the third power supply are respectively connected to the first end of the upper bridge arm circuit, and the other ends of the first ammeter, the second ammeter and the third ammeter are respectively connected between the upper bridge arm circuit and the lower bridge arm circuit;

[0015] When the lower bridge arm circuit is tested, a third signal generator is also included, a first end of the third signal generator is connected to the LIN port of the HVIC chip, and a second end of the third signal generator is grounded; the other ends of the first power supply, the second power supply and the third power supply are respectively connected between the upper bridge arm circuit and the lower bridge arm circuit, and the other ends of the first ammeter, the second ammeter and the third ammeter are respectively connected to the ground end of the lower bridge arm circuit.

[0016] In a second aspect, an embodiment of the present invention provides a method for testing an overcurrent protection threshold of an intelligent power module. The testing method is implemented based on the above-mentioned intelligent power module overcurrent protection threshold testing circuit. The testing method includes the following steps:

[0017] S1, start the thermostat and set the temperature to the preset temperature;

[0018] S2, start the first DC power supply and set it to 15V, and supply power to the VCC port of the intelligent power module;

[0019] S3, start the second DC power supply and set it to 15V to supply power to the VB1, VB2 and VB3 ports of the HVIC chip;

[0020] S4, start the second power supply and set it to 5V to supply power to the FLTEN port of the HVIC chip;

[0021] S5, start the first signal generator to output a pulse signal to the HIN port;

[0022] S6, start the first power supply, the second power supply and the third power supply and set them to 1V, and supply power to the VS1, VS2 and VS3 ports of the HVIC chip respectively;

[0023] S7, start the second signal generator to output a pulse signal to the ITRIP port;

[0024] S8, monitoring the ITRIP port input signal HIN through an oscilloscope;

[0025] S9, collect and record the ITRIP port input voltage V when the current of the upper bridge arm circuit is less than 1mA during the process of the ITRIP port input rising from 0V to 5V. ITRIP1 ;

[0026] S10, collect and record the ITRIP port input voltage V when the current of the upper bridge arm circuit is greater than 1mA during the process of the ITRIP port input dropping from 5V to 0V. ITRIP2 ;

[0027] S11. Determine V IRTIP+ (95%) <V IRTIP1 <V IRTIP+ (1+5%);

[0028] V IRTIP- (95%) <V IRTIP2 <V IRTIP- (1+5%); whether it meets the requirements, if yes, then cycle through S1-S9; if not, then the test ends and the product fails.

[0029] Preferably, the preset temperature of S1 is 25°C.

[0030] Preferably, the preset temperature of S1 is -40°C.

[0031] Preferably, the preset temperature of S1 is 125°C.

[0032] Compared with the prior art, the beneficial effect of the present invention lies in that, by connecting the first end of the first power supply to the VCC port of the intelligent power module, the second end of the first power supply to the ground terminal of the intelligent power module, the first end of the first signal generator to the HIN port of the intelligent power module, and the second end of the first signal generator to the ground; the first end of the second signal generator to the ITRIP port of the intelligent power module, the second end of the second signal generator to the ground, the first end of the first resistor to the FLTEN port of the intelligent power module, the second end of the first resistor to the first end of the second power supply, and the second end of the second power supply to the ground; the first end of the first isolated power supply is connected to the VB1 port of the intelligent power module, the first end of the second isolated power supply is connected to the VB2 port of the intelligent power module, the first end of the third isolated power supply is connected to the VB3 port of the intelligent power module, the second end of the first isolated power supply, the second end of the second isolated power supply and the second end of the third isolated power supply are respectively connected to the first ends of multiple power supplies, the second ends of the multiple power supplies are connected to the first ends of multiple ammeters, and the second ends of the multiple ammeters are connected to the bridge arm circuit of the intelligent power module, so as to realize the test of the bridge arm circuit. Test the IPM intelligent power module overcurrent protection shutdown threshold and reset threshold at different temperatures. Increase the ITRIP input voltage at the overcurrent protection signal input pin ITRIP. When the output IGBT current is less than 1mA, detect the ITRIP input voltage V ITRIP+ , reduce the ITRIP input voltage, when the output IGBT current is greater than 9mA, detect the ITRIP input voltage V ITRIP- , in order to verify the IPM intelligent power module overcurrent protection shutdown threshold and reset threshold V ITRIP+、 V ITRIP- Whether it is qualified, so as to prevent products with unqualified overcurrent protection shutdown threshold and reset threshold from entering the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be described in detail below in conjunction with the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings. In the accompanying drawings:

[0034] Figure 1 It is a circuit diagram of an upper bridge arm test of an overcurrent protection threshold test circuit of an intelligent power module provided by an embodiment of the present invention;

[0035] Figure 2 It is a circuit diagram of a lower bridge arm test of an overcurrent protection threshold test circuit of an intelligent power module provided by an embodiment of the present invention;

[0036] Figure 3 is a waveform diagram of a first signal generator and a third signal generator provided by an embodiment of the present invention;

[0037] Figure 4is a waveform diagram of a second signal generator provided by an embodiment of the present invention;

[0038] Figure 5 It is a timing diagram of an upper bridge arm circuit test of an overcurrent protection threshold test circuit of an intelligent power module provided by an embodiment of the present invention;

[0039] Figure 6 It is a timing diagram of a lower bridge arm circuit test of an overcurrent protection threshold test circuit of an intelligent power module provided by an embodiment of the present invention;

[0040] Figure 7 is a flow chart of a method for testing an overcurrent protection threshold of an intelligent power module provided by an embodiment of the present invention;

[0041] Figure 8 The present invention is a flowchart of different temperatures of a method for testing an overcurrent protection threshold of an intelligent power module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] First, combined with the Figure 1-Figure 6 As shown, an embodiment of the present invention provides an intelligent power module overcurrent protection threshold test circuit, which is used to test an intelligent power module 0201, including: a first power supply 0212, a first signal generator 0211, a second signal generator 0214, a second power supply 0213, a first isolated power supply 0202, a second isolated power supply 0203, a third isolated power supply 0204, multiple power supplies, multiple ammeters and a first resistor R1;

[0044] A first end of the first power supply 0212 is connected to a VCC port of the intelligent power module 0201, a second end of the first power supply 0212 is connected to a ground terminal of the intelligent power module 0201, a first end of the first signal generator 0211 is connected to a HIN port of the intelligent power module 0201, and a second end of the first signal generator 0211 is grounded;

[0045] A first end of the second signal generator 0214 is connected to the ITRIP port of the intelligent power module 0201, a second end of the second signal generator 0214 is grounded, a first end of the first resistor R1 is connected to the FLTEN port of the intelligent power module 0201, a second end of the first resistor R1 is connected to a first end of the second power supply 0213, and a second end of the second power supply 0213 is grounded;

[0046] The first end of the first isolated power supply 0202 is connected to the VB1 port of the intelligent power module 0201, the first end of the second isolated power supply 0203 is connected to the VB2 port of the intelligent power module 0201, the first end of the third isolated power supply 0204 is connected to the VB3 port of the intelligent power module 0201, the second end of the first isolated power supply 0202, the second end of the second isolated power supply 0203 and the second end of the third isolated power supply 0204 are respectively connected to the first ends of multiple power supplies, the second ends of the multiple power supplies are connected to the first ends of multiple ammeters, and the second ends of the multiple ammeters are connected to the bridge arm circuit of the intelligent power module 0201 to test the bridge arm circuit.

[0047] Specifically, the first end of the first power supply 0212 is connected to the VCC port of the intelligent power module 0201, the second end of the first power supply 0212 is connected to the ground terminal of the intelligent power module 0201, the first end of the first signal generator 0211 is connected to the HIN port of the intelligent power module 0201, and the second end of the first signal generator 0211 is grounded; the first end of the second signal generator 0214 is connected to the ITRIP port of the intelligent power module 0201, the second end of the second signal generator 0214 is grounded, the first end of the first resistor R1 is connected to the FLTEN port of the intelligent power module 0201, and the second end of the first resistor R1 is connected to the first The first end of the first isolated power supply 0202 is connected to the VB1 port of the intelligent power module 0201, the first end of the second isolated power supply 0203 is connected to the VB2 port of the intelligent power module 0201, the first end of the third isolated power supply 0204 is connected to the VB3 port of the intelligent power module 0201, the second end of the first isolated power supply 0202, the second end of the second isolated power supply 0203 and the second end of the third isolated power supply 0204 are respectively connected to the first ends of multiple power supplies, the second ends of the multiple power supplies are connected to the first ends of multiple ammeters, and the second ends of the multiple ammeters are connected to the bridge arm circuit of the intelligent power module 0201 to test the bridge arm circuit. The overcurrent protection shutdown threshold and reset threshold of the IPM intelligent power module 0201 are tested at different temperatures. At the overcurrent protection signal input pin ITRIP, the ITRIP input voltage is increased. When the output IGBT current is less than 1m A, the input voltage V of ITRIP is detected. ITRIP+ , reduce the ITRIP input voltage, when the output IGBT current is greater than 9mA, detect the ITRIP input voltage V ITRIP- , in order to achieve the test IPM intelligent power module 0201 overcurrent protection shutdown threshold and reset threshold V ITRIP+、 V ITRIP- Whether it is qualified, so as to prevent products with unqualified overcurrent protection shutdown threshold and reset threshold from entering the market.

[0048] In this embodiment, the bridge arm circuit includes an upper bridge arm circuit and a lower bridge arm circuit, and the upper bridge arm circuit is connected to the lower bridge arm circuit; the first ends of multiple power supplies are connected to the first end of the upper bridge arm circuit or the lower bridge arm circuit, and the second ends of multiple ammeters are connected to the second end of the upper bridge arm circuit or the lower bridge arm circuit.

[0049] In this embodiment, the upper bridge arm circuit includes a first transistor Q1, a second transistor Q2 and a third transistor Q3; the lower bridge arm circuit includes a fourth transistor Q4, a fifth transistor Q5 and a sixth transistor Q6;

[0050] The source of the first transistor Q1 is connected to the drain of the fourth transistor Q4, the gate of the first transistor Q1 is connected to the HO1 port of the HVIC chip of the intelligent power module 0201, the gate of the fourth transistor Q4 is connected to the LO1 port of the HVIC chip, and the drain of the first transistor Q1 is respectively connected to the drain of the second transistor Q2 and the drain of the third transistor Q3; the gate of the second transistor Q2 is connected to the HO3 port of the HVC chip, the source of the second transistor Q2 is connected to the VS2 port of the HVIC chip and the drain of the fifth transistor Q5, the source of the fourth transistor Q4, the source of the fifth transistor Q5 and the source of the sixth transistor Q6 are grounded; the gate of the fifth transistor Q5 is connected to the LO2 port of the HVIC chip, and the gate of the sixth transistor Q6 is connected to the LO3 port of the HVIC chip; the gate of the third transistor Q3 is connected to the HO3 port of the HVIC chip, and the source of the third transistor Q3 is connected to the drain of the sixth transistor Q6.

[0051] In this embodiment, the plurality of power supplies include a first power supply 0205, a second power supply 0206 and a third power supply 0207, and the plurality of ammeters include a first ammeter 0208, a second ammeter 0209 and a third ammeter 0210; one end of the first power supply 0205, the second power supply 0206 and the third power supply 0207 are connected in series with one end of the first ammeter 0208, the second ammeter 0209 and the third ammeter 0210 respectively;

[0052] When testing the upper bridge arm circuit, the other ends of the first power supply 0205, the second power supply 0206 and the third power supply 0207 are respectively connected to the first end of the upper bridge arm circuit, and the other ends of the first ammeter 0208, the second ammeter 0209 and the third ammeter 0210 are respectively connected between the upper bridge arm circuit and the lower bridge arm circuit;

[0053] When the lower bridge arm circuit is tested, it also includes a third signal generator 0311, a first end of the third signal generator 0311 is connected to the LIN port of the HVIC chip, and a second end of the third signal generator 0311 is grounded; the other ends of the first power supply 0205, the second power supply 0206 and the third power supply 0207 are respectively connected between the upper bridge arm circuit and the lower bridge arm circuit, and the other ends of the first ammeter 0208, the second ammeter 0209 and the third ammeter 0210 are respectively connected to the ground end of the lower bridge arm circuit.

[0054] In this embodiment, Figure 3 0211 and 0311 are PWM HIN and LIN output by the first signal generator 0211 and the third signal generator 0311. The period of PWM is T, the pulse width is W, the high level is 5V, and the low level is 0V square wave. Figure 4 It is the PWM ITRIP output by the second signal generator 0214. The PWM period is T, the pulse width is W, the high level is 5V, the low level is 0V square wave, the rise time is ton, and the fall time is toff. Figure 5 This is the IPM intelligent power module 0201 overcurrent protection threshold voltage (upper bridge arm) test timing diagram; Figure 6 This is the IPM intelligent power module 0201 overcurrent protection threshold voltage (lower bridge arm) test timing diagram.

[0055] In a second aspect, an embodiment of the present invention provides a method for testing an overcurrent protection threshold of an intelligent power module 0201. The testing method is implemented based on the above-mentioned overcurrent protection threshold testing circuit of the intelligent power module 0201. The testing method includes the following steps:

[0056] S1, start the thermostat and set the temperature to the preset temperature;

[0057] S2, start the first DC power supply and set it to 15V, and supply power to the VCC port of the intelligent power module 0201;

[0058] S3, start the second DC power supply and set it to 15V to supply power to the VB1, VB2 and VB3 ports of the HVIC chip;

[0059] S4, start the second power supply 0213 and set it to 5V to supply power to the FLTEN port of the HVIC chip;

[0060] S5, start the first signal generator 0211 to output a pulse signal to the HIN port;

[0061] S6, start the first power supply 0205, the second power supply 0206 and the third power supply 0207 and set them to 1V to supply power to the VS1, VS2 and VS3 ports of the HVIC chip respectively;

[0062] S7, start the second signal generator 0214 to output a pulse signal to the ITRIP port;

[0063] S8, monitoring the ITRIP port input signal HIN through an oscilloscope;

[0064] S9, collect and record the ITRIP port input voltage V when the current of the upper bridge arm circuit is less than 1mA during the process of the ITRIP port input rising from 0V to 5V. ITRIP1 ;

[0065] S10, collect and record the ITRIP port input voltage V when the current of the upper bridge arm circuit is greater than 1mA during the process of the ITRIP port input dropping from 5V to 0V. ITRIP2 ;

[0066] S11. Determine V IRTIP+ (95%) <V IRTIP1 <V IRTIP+ (1+5%);

[0067] V IRTIP- (95%) <V IRTIP2 <V IRTIP- (1+5%); whether it meets the requirements, if yes, then cycle through S1-S9; if not, then the test ends and the product fails.

[0068] In this embodiment, the preset temperature of S1 is 25°C.

[0069] In this embodiment, the preset temperature of S1 is -40°C.

[0070] In this embodiment, the preset temperature of S1 is 125°C.

[0071] Specifically, this test method tests the IPM intelligent power module 0201 overcurrent protection shutdown threshold V at different temperatures. ITRIP+ and reset threshold V ITRIP- , at the overcurrent protection signal input pin ITRIP, increase the ITRIP input voltage, when the upper and lower bridge arm output IGBT current is less than 1m A sudden change, detect the ITRIP input voltage V ITRIP+ , reduce the ITRIP input voltage, when the upper and lower bridge arm output IGBT current is greater than 9mA, detect the ITRIP input voltage V ITRIP- , in order to achieve the test IPM intelligent power module 0201 overcurrent protection shutdown threshold and reset threshold V ITRIP+、 V ITRIP- Whether it is qualified, so as to prevent products with unqualified overcurrent protection shutdown threshold and reset threshold from entering the market.

[0072] The working power supply of IPM intelligent power module 0201 is 12V-20V, the commonly used working power supply is generally 15V, and the working temperature is -40℃-125℃. The working characteristics of IPM intelligent power module 0201 will change to a certain extent at different temperatures. Therefore, to determine whether the performance of an IPM intelligent power module 0201 meets the standards, it is necessary to test the parameters of each functional circuit at different temperatures to see whether they meet the standards.

[0073] This test method: Under 15V power supply, select three temperatures for testing: the highest temperature 125℃, the normal temperature 25℃, and the lowest temperature -40℃.

[0074] This test method is mainly to test V ITRIP When setting voltage parameters, shorter wires should be used to reduce the impact of parasitic capacitance on the results.

[0075] Test equipment, 1. Temperature control box: temperature control range: -45℃~145℃; control accuracy: 1℃.

[0076] 2.Signal generator: dual-ended output; >20V Vp-p; >0.5A current output capability; >500MHz bandwidth.

[0077] 3. Oscilloscope: Four inputs; >500MHz bandwidth.

[0078] 4. Ammeter: multiple reading ammeter, maximum reading current>100mA, minimum reading current>0.1mA, 5. Power supply: maximum output voltage>20V; maximum output current>0.5A.

[0079] Test standard: Since the upper and lower bridge IGBTs of the same bridge arm cannot be turned on at the same time, the overcurrent protection V ITRIP Threshold, at different temperatures, divided into upper bridge arm overcurrent protection threshold test and lower bridge arm overcurrent protection threshold test. V ITRIP The thresholds are theoretically the same. The test results are within plus or minus 5%, and the tested intelligent power module 0201IPM is qualified. By testing the overcurrent protection shutdown threshold and reset threshold of the IPM intelligent power module 0201 at different temperatures, the overcurrent protection signal input pin ITRIP pin is increased, the ITRIP input voltage is detected when the output IGBT current is less than 1m A sudden change ITRIP+ , reduce the ITRIP input voltage, when the output IGBT current is greater than 9mA, detect the ITRIP input voltage V ITRIP- , in order to achieve the test IPM intelligent power module 0201 overcurrent protection shutdown threshold and reset threshold V ITRIP+、 V ITRIP-Whether it is qualified, so as to prevent products with unqualified overcurrent protection shutdown threshold and reset threshold from entering the market.

[0080] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of more restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, article or device including the element.

[0081] The embodiments of the present invention are described above in conjunction with the accompanying drawings. What is disclosed is only the preferred embodiment of the present invention. However, the present invention is not limited to the above-mentioned specific implementation manner. The above-mentioned specific implementation manner is only illustrative rather than restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms and equivalent changes without departing from the scope of protection of the purpose of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. An intelligent power module overcurrent protection threshold test circuit, used for testing an intelligent power module, characterized in that: include: A first power supply, a first signal generator, a second signal generator, a second power supply, a first isolated power supply, a second isolated power supply, a third isolated power supply, a plurality of power supplies, a plurality of ammeters and a first resistor; A first end of the first power supply is connected to a VCC port of the intelligent power module, a second end of the first power supply is connected to a ground terminal of the intelligent power module, a first end of the first signal generator is connected to a HIN port of the intelligent power module, and a second end of the first signal generator is grounded; The first end of the second signal generator is connected to the ITRIP port of the intelligent power module, the second end of the second signal generator is grounded, the first end of the first resistor is connected to the FLTEN port of the intelligent power module, the second end of the first resistor is connected to the first end of the second power supply, and the second end of the second power supply is grounded; The first end of the first isolated power supply is connected to the VB1 port of the intelligent power module, the first end of the second isolated power supply is connected to the VB2 port of the intelligent power module, the first end of the third isolated power supply is connected to the VB3 port of the intelligent power module, the second end of the first isolated power supply, the second end of the second isolated power supply and the second end of the third isolated power supply are respectively connected to the first ends of multiple power supplies, the second ends of the multiple power supplies are connected to the first ends of multiple ammeters, and the second ends of the multiple ammeters are connected to the bridge arm circuit of the intelligent power module to implement testing of the bridge arm circuit.

2. The intelligent power module overcurrent protection threshold test circuit according to claim 1, characterized in that: The bridge arm circuit includes an upper bridge arm circuit and a lower bridge arm circuit, and the upper bridge arm circuit is connected to the lower bridge arm circuit; the first ends of multiple power supplies are connected to the first end of the upper bridge arm circuit or the lower bridge arm circuit, and the second ends of multiple ammeters are connected to the second end of the upper bridge arm circuit or the lower bridge arm circuit.

3. The intelligent power module overcurrent protection threshold test circuit according to claim 2, characterized in that: The upper bridge arm circuit includes a first transistor, a second transistor and a third transistor; the lower bridge arm circuit includes a fourth transistor, a fifth transistor and a sixth transistor; The source of the first transistor is connected to the drain of the fourth transistor, the gate of the first transistor is connected to the HO1 port of the HVIC chip of the intelligent power module, the gate of the fourth transistor is connected to the LO1 port of the HVIC chip, and the drain of the first transistor is respectively connected to the drain of the second transistor and the drain of the third transistor; the gate of the second transistor is connected to the HO3 port of the HVC chip, the source of the second transistor is connected to the VS2 port of the HVIC chip and the drain of the fifth transistor, the source of the fourth transistor, the source of the fifth transistor and the source of the sixth transistor are grounded; the gate of the fifth transistor is connected to the LO2 port of the HVIC chip, and the gate of the sixth transistor is connected to the LO3 port of the HVIC chip; the gate of the third transistor is connected to the HO3 port of the HVIC chip, and the source of the third transistor is connected to the drain of the sixth transistor.

4. The intelligent power module overcurrent protection threshold test circuit according to claim 3, characterized in that: The multiple power supplies include a first power supply, a second power supply and a third power supply, and the multiple ammeters include a first ammeter, a second ammeter and a third ammeter; one end of the first power supply, the second power supply and the third power supply is connected in series with one end of the first ammeter, the second ammeter and the third ammeter respectively; When testing the upper bridge arm circuit, the other ends of the first power supply, the second power supply and the third power supply are respectively connected to the first end of the upper bridge arm circuit, and the other ends of the first ammeter, the second ammeter and the third ammeter are respectively connected between the upper bridge arm circuit and the lower bridge arm circuit; When the lower bridge arm circuit is tested, a third signal generator is also included, a first end of the third signal generator is connected to the LIN port of the HVIC chip, and a second end of the third signal generator is grounded; the other ends of the first power supply, the second power supply and the third power supply are respectively connected between the upper bridge arm circuit and the lower bridge arm circuit, and the other ends of the first ammeter, the second ammeter and the third ammeter are respectively connected to the ground end of the lower bridge arm circuit.

5. A method for testing an overcurrent protection threshold of an intelligent power module, characterized in that: The test method is implemented based on the intelligent power module overcurrent protection threshold test circuit according to any one of claims 1 to 4, and the test method comprises the following steps: S1, start the thermostat and set the temperature to the preset temperature; S2, start the first DC power supply and set it to 15V, and supply power to the VCC port of the intelligent power module; S3, start the second DC power supply and set it to 15V to supply power to the VB1, VB2 and VB3 ports of the HVIC chip; S4, start the second power supply and set it to 5V to supply power to the FLTEN port of the HVIC chip; S5, start the first signal generator to output a pulse signal to the HIN port; S6, start the first power supply, the second power supply and the third power supply and set them to 1V, and supply power to the VS1, VS2 and VS3 ports of the HVIC chip respectively; S7, start the second signal generator to output a pulse signal to the ITRIP port; S8, monitoring the ITRIP port input signal HIN through an oscilloscope; S9, collect and record the ITRIP port input voltage V when the current of the upper bridge arm circuit is less than 1mA during the process of the ITRIP port input rising from 0V to 5V. ITRIP1 ; S10, collect and record the ITRIP port input voltage V when the current of the upper bridge arm circuit is greater than 1mA during the process of the ITRIP port input dropping from 5V to 0V. ITRIP2 ; S11. Determine V IRTIP+ (95%) <V IRTIP1 <V IRTIP+ (1+5%); V IRTIP- (95%) <V IRTIP2 <V IRTIP- (1+5%); whether it meets the requirements, if yes, then cycle through S1-S9; if not, then the test ends and the product fails.

6. The method for testing the overcurrent protection threshold of an intelligent power module according to claim 5, characterized in that: The preset temperature of S1 is 25°C.

7. The method for testing the overcurrent protection threshold of an intelligent power module according to claim 6, characterized in that: The preset temperature of S1 is -40°C.

8. The method for testing the overcurrent protection threshold of an intelligent power module according to claim 7, characterized in that: The preset temperature of S1 is 125°C.

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