Switch parameter test circuit

Abstract

The utility model provides a switch parameter test circuit, and relates to the technical field of electronic circuits. The switch parameter test circuit comprises a signal input unit, a parameter test circuit unit and an acquisition unit. When the signal input unit inputs a high level signal to the parameter test circuit unit, the parameter test circuit can charge the gate of the silicon carbide transistor to be tested, so that the silicon carbide transistor is in a conducting state. When the signal input unit inputs a low-level signal to the parameter test circuit unit, the parameter test circuit can reversely extract the grid charges stored in the silicon carbide transistor, quickly remove the grid charges and maintain the negative grid source voltage of the silicon carbide transistor, so that the silicon carbide transistor is in a turn-off state. In addition, the electrical change of the silicon carbide transistor in the process can be acquired through the acquisition unit, so that the switching parameters of the silicon carbide transistor are obtained.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technologies, and more particularly, to a switching parameter test circuit. Background Art

[0002] With the continuous development of electronic technologies, silicon carbide transistors are widely used in high-power converters, motor drives, solar inverters and other fields due to their excellent high-temperature stability, high efficiency and fast switching characteristics. In the circuit design of silicon carbide transistors, their switching parameters play an important role, and how to accurately measure the switching parameters of silicon carbide transistors has become an important research issue.

[0003] Since silicon carbide transistors are different from ordinary silicon transistors, in order to accurately measure the switching parameters of silicon carbide transistors, it is usually necessary to maintain an accurate and stable negative gate-source voltage (usually -5V to -2V) when the silicon carbide transistor is in the off state. The negative gate-source voltage requirement for some special devices can be as low as -10V, but existing test circuits usually cannot enable the silicon carbide transistor to maintain an accurate and stable negative gate-source voltage. Utility Model Content

[0004] In order to at least overcome the above deficiencies in the prior art, the purpose of this application is to provide a switching parameter test circuit.

[0005] In a first aspect, an embodiment of this application provides a switching parameter test circuit, which includes a signal input unit, a parameter test circuit unit, and a collection unit;

[0006] The signal input unit is connected to the input end of the parameter test circuit unit to provide an input signal for the parameter test circuit unit;

[0007] The output end of the parameter test circuit unit is connected to the control electrode of the silicon carbide transistor to be tested, and is used to control the on or off of the silicon carbide transistor to be tested based on the input input signal;

[0008] The first end of the collection unit is connected to an electrode of the silicon carbide transistor to be tested, and is used to collect the electrical parameters of the silicon carbide transistor to be tested in the on or off state.

[0009] In a possible implementation, the parameter test circuit unit includes a signal processing chip, and the signal processing chip includes an input end, an output end, and a Miller clamping end;

[0010] The input end is connected to the signal input unit, and the output end and the Miller clamping end are respectively connected to the gate of the silicon carbide transistor to be tested; where

[0011] When a high-level signal is input to the signal input unit, the output terminal outputs a high level to control the conduction of the silicon carbide transistor to be tested; when a low-level signal is input to the signal input unit, the Miller clamp terminal outputs a low level to control the turn-off of the silicon carbide transistor to be tested.

[0012] In a possible implementation, the parameter test circuit unit further includes a first resistor;

[0013] One end of the first resistor is connected to the output terminal, and the other end of the first resistor is connected to the gate of the silicon carbide transistor. The first resistor is used to limit the current output by the signal output terminal.

[0014] In a possible implementation, the signal processing chip further includes a first power input terminal, a second power input terminal, and a negative power input terminal;

[0015] The first power input terminal is connected to a first power supply. The first power supply provides a driving power supply for the internal logic circuit of the signal processing sub-unit through the first power input terminal;

[0016] The second power input terminal is connected to a second power supply. The second power supply provides a driving power supply for the internal driving circuit of the signal processing sub-unit through the second power input terminal;

[0017] The negative power input terminal is connected to a negative power supply. The negative power input terminal provides a negative power supply for the internal driving circuit of the signal processing sub-unit through the negative power input terminal. Among them, the voltage of the second power supply is greater than the voltage of the negative power supply.

[0018] In a possible implementation, the voltage of the first power supply is +5V;

[0019] The voltage of the second power supply is 12V to 15V, and the voltage of the negative power supply is -5V to -2V.

[0020] In a possible implementation, the switch parameter test circuit further includes a freewheeling and energy storage unit;

[0021] The freewheeling and energy storage unit is connected to the second end of the acquisition unit. The freewheeling and energy storage unit is used to provide energy storage and freewheeling current for the silicon carbide transistor to be tested.

[0022] In a possible implementation, the freewheeling and energy storage unit includes a first inductor and a diode;

[0023] One end of the first inductor is connected to the acquisition unit, and the other end is connected to a fourth power supply;

[0024] The anode of the diode is connected to the acquisition unit, and the cathode of the diode is connected to the fourth power supply.

[0025] In a possible implementation, the signal input unit includes a signal generator. The signal generator includes a signal output terminal and a first grounding terminal, and the signal processing chip further includes a grounded second grounding terminal.

[0026] The signal output terminal is connected to the input terminal, and the first grounding terminal is connected to the second grounding terminal.

[0027] In a possible implementation, the acquisition unit includes an oscilloscope.

[0028] In a possible implementation, the signal processing chip includes a MAX22701E chip.

[0029] Based on any of the above aspects, the switching parameter test circuit provided by the embodiments of the present application includes a signal input unit, a parameter test circuit unit, and an acquisition unit. When the signal input unit inputs a high-level signal to the parameter test circuit unit, the parameter test circuit can charge the silicon carbide transistor to be tested, so that the silicon carbide transistor is in a conducting state. When the signal input unit inputs a low-level signal to the parameter test circuit unit, the parameter test circuit can reversely extract the gate charge stored in the silicon carbide transistor, quickly remove the gate charge, and at the same time can maintain the negative gate-source voltage of the silicon carbide transistor, so that the silicon carbide transistor is in an off state. In addition, the acquisition unit can collect the electrical property changes of the silicon carbide transistor in the above process to obtain the switching parameters of the silicon carbide transistor. Description of the Drawings

[0030] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be called in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0031] Figure 1 A possible module schematic diagram of the switching parameter test circuit provided by the present application;

[0032] Figure 2 A possible circuit schematic diagram of the switching parameter test circuit provided by the present application;

[0033] Figure 3 A partial circuit schematic diagram of the switching parameter test circuit provided by the present application;

[0034] Figure 4Another possible circuit schematic diagram of the switch parameter test circuit provided for this application.

[0035] Icon:

[0036] 110 - Signal input unit; 120 - Parameter test circuit unit; 130 - Acquisition unit; 140 - Freewheeling and energy storage unit. Detailed implementation manners

[0037] To make the objectives, technical solutions and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some but not all of the embodiments of this application. Usually, the components of the embodiments of this application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application claimed, but is merely representative of the selected embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the scope of protection of this application.

[0039] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0040] In the description of this application, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0041] In the description of this application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "connected", "coupled", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] It should be noted that, without conflict, different features in the embodiments of the present application can be combined with each other.

[0043] To solve the problems in the prior art, please refer to Figure 1 , an embodiment of the present application provides a switching parameter test circuit, and the switching parameter test circuit includes a signal input unit 110, a parameter test circuit unit 120, and an acquisition unit 130.

[0044] The signal input unit 110 is connected to the input end of the parameter test circuit unit 120 to provide an input signal for the parameter test circuit unit 120. The output end of the parameter test circuit unit 120 is connected to the control electrode of the silicon carbide transistor 20 to be tested, and the parameter test circuit unit 120 can control the conduction or cut-off of the silicon carbide transistor 20 to be tested based on the input input signal. Among them, the control electrode can be a gate.

[0045] The first end of the acquisition unit 130 is connected to an electrode of the silicon carbide transistor 20 to be tested, and is used to acquire the electrical parameters of the silicon carbide transistor 20 to be tested in the conduction and cut-off states. Specifically, the acquisition unit 130 can acquire the gate voltage waveform, drain current waveform, and drain-source voltage waveform of the silicon carbide transistor 20 to be tested in the conduction and cut-off states, etc., and obtain the switching parameters of the silicon carbide transistor 20 by analyzing the above waveform diagrams. Among them, the acquisition unit 130 can include an oscilloscope.

[0046] In the above structure, when the signal input unit 110 inputs a high-level signal to the parameter test circuit unit 120, the parameter test circuit 120 can charge the gate of the silicon carbide transistor 20 to be tested, so that the silicon carbide transistor 20 is in a conduction state. When the signal input unit 110 inputs a low-level signal to the parameter test circuit unit 120, the parameter test circuit 120 can reversely extract the gate charge stored in the silicon carbide transistor 20, quickly remove the gate charge, and at the same time can maintain the negative gate-source voltage of the silicon carbide transistor 20, so that the silicon carbide transistor 20 is in a cut-off state. In addition, the acquisition unit 130 can acquire the electrical changes of the silicon carbide transistor 20 in the above process, so as to obtain the switching parameters of the silicon carbide transistor 20.

[0047] In some possible embodiments, please refer to Figure 2 , the parameter test circuit unit 120 includes a signal processing chip U1, and the signal processing chip U1 can include an input end IN, an output end OUT, and a Miller clamp end CLAMP.

[0048] The input terminal IN is connected to the signal input unit 110, and the output terminal OUT and the Miller clamp terminal CLAMP are respectively connected to the gate of the silicon carbide transistor to be tested. Specifically, the parameter test circuit unit 120 may further include a first resistor R. One end of the first resistor R is connected to the signal output terminal OUT, and the other end of the first resistor R is connected to the gate of the silicon carbide transistor 20. When a high-level signal is input by the signal input unit 110, the high level output by the output terminal OUT charges the gate of the silicon carbide transistor 20 to be tested through the first resistor R. Among them, the first resistor R can limit the current output by the signal output terminal OUT, control the charging speed of the gate of the silicon carbide transistor 20, and at the same time prevent the gate voltage from suddenly changing and damaging the internal drive circuit of the silicon carbide transistor 20 or the signal processing chip U1.

[0049] When a low-level signal is input by the signal input unit 110, the Miller clamp terminal CLAMP outputs a low level to control the silicon carbide transistor 20 to be tested to turn off. Among them, the Miller clamp terminal CLAMP can also clamp the gate voltage in the cut-off state, protecting the silicon carbide transistor 20 from voltage spikes while ensuring that the gate voltage is maintained at the required negative voltage level.

[0050] Furthermore, the signal processing chip U1 further includes a first power input terminal VDDA, a second power input terminal VDDB, and a negative power input terminal VSSB.

[0051] The first power input terminal VDDA is connected to the first power supply VCC1. The first power supply VCC1 provides a driving power supply for the internal logic circuit of the signal processing sub-unit through the first power input terminal VDDA. Among them, the voltage of the first power supply VCC1 is +5V.

[0052] The second power input terminal VDDB is connected to the second power supply VCC2. The second power supply VCC2 provides a driving power supply for the internal drive circuit of the signal processing sub-unit through the second power input terminal VDDB. The negative power input terminal VSSB is connected to the negative power supply VSS. The negative power input terminal VSSB provides the negative power supply VSS for the internal drive circuit of the signal processing sub-unit through the negative power input terminal VSSB. The voltage of the second power supply VCC2 is greater than the voltage of the negative power supply VSS. Specifically, the second power supply VCC2 is a positive voltage power supply, and the negative power supply VSS is a negative voltage power supply. Exemplarily, the voltage of the second power supply VCC2 can be 12V to 15V, and the voltage of the negative power supply VSS can be -5V to -2V.

[0053] Specifically, when the signal input unit 110 inputs a high-level signal to the signal processing chip U1, the positive voltage power supply can charge the gate of the silicon carbide transistor 20 to be tested through the second power input terminal VDDB and the output terminal OUT. The above process is the conduction process of the silicon carbide transistor 20. When the signal input unit 110 inputs a high-level signal to the signal processing chip U1, the internal drive circuit can quickly reverse-extract the gate charge stored in the silicon carbide transistor 20. After the extraction of the gate charge is completed, the negative voltage power supply can apply a negative voltage to the gate of the silicon carbide transistor 20 through the negative power input terminal VSSB and the Miller clamp terminal CLAMP to ensure that the gate voltage is maintained at the required negative voltage level.

[0054] Furthermore, the signal input unit 110 may include a signal generator. The signal generator includes a signal output terminal and a first grounding terminal. The signal processing chip U1 further includes a grounded second grounding terminal GNDA. The signal output terminal of the signal generator can be connected to the input terminal IN of the signal processing chip U1, and the first grounding terminal can be connected to the second grounding terminal GNDA to provide a high-level signal or a low-level signal to the signal processing chip U1. The signal processing chip U1 may include a MAX22701E chip, and the chip may further include an active-low enable terminal EN.

[0055] Please refer to Figure 3 and Figure 4 , the switching parameter test circuit further includes a freewheeling and energy storage unit 140. The freewheeling and energy storage unit 140 is connected to the second terminal of the acquisition unit 130, and the freewheeling and energy storage unit 140 is used to provide energy storage and freewheeling current for the silicon carbide transistor 20 to be tested. Specifically, the freewheeling and energy storage unit 140 may include a first inductor L and a diode D. One end of the first inductor L is connected to the acquisition unit 130, and the other end is connected to the third power supply VCC3. The anode of the diode D is connected to the acquisition unit 130, and the cathode of the diode D is connected to the third power supply VCC3. When the silicon carbide transistor is in the cut-off state, the diode D can provide a continuous current freewheeling path for the silicon carbide transistor to prevent transistor damage caused by current mutation. Among them, the third power supply VCC3 can be determined according to the rated voltage value of the silicon carbide transistor 20 to be tested.

[0056] In summary, the embodiment of the present application provides a switching parameter test circuit, which includes a signal input unit, a parameter test circuit unit, and a collection unit. When the signal input unit inputs a high-level signal to the parameter test circuit unit, the parameter test circuit can charge the gate of the silicon carbide transistor to be tested, so that the silicon carbide transistor is in the on state. When the signal input unit inputs a low-level signal to the parameter test circuit unit, the parameter test circuit can reversely extract the gate charge stored in the silicon carbide transistor, quickly remove the gate charge, and at the same time can maintain the negative gate-source voltage of the silicon carbide transistor, so that the silicon carbide transistor is in the off state. In addition, the collection unit can collect the electrical changes of the silicon carbide transistor in the above process to obtain the switching parameters of the silicon carbide transistor.

[0057] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A switch parameter test circuit, characterized in that: It includes a signal input unit, a parameter test circuit unit and a collection unit; The signal input unit is connected to the input end of the parameter test circuit unit to provide an input signal to the parameter test circuit unit; The output end of the parameter test circuit unit is connected to the control electrode of the silicon carbide transistor to be tested, and is used to control the on or off of the silicon carbide transistor to be tested based on the input signal; The first end of the acquisition unit is connected to an electrode of the silicon carbide transistor to be tested, and is used to acquire electrical parameters of the silicon carbide transistor to be tested in an on or off state.

2. The switch parameter test circuit according to claim 1, characterized in that: The parameter test circuit unit includes a signal processing chip, and the signal processing chip includes an input terminal, an output terminal and a Miller clamp terminal; The input end is connected to the signal input unit, and the output end and the Miller clamp end are respectively connected to the gate of the silicon carbide transistor to be tested; wherein, When the signal input unit inputs a high-level signal, the output end outputs a high level to control the silicon carbide transistor to be tested to be turned on; when the signal input unit inputs a low-level signal, the Miller clamp end outputs a low level to control the silicon carbide transistor to be tested to be turned off.

3. The switch parameter test circuit according to claim 2, characterized in that: The parameter test circuit unit also includes a first resistor; One end of the first resistor is connected to the output end, and the other end of the first resistor is connected to the gate of the silicon carbide transistor. The first resistor is used to limit the current output by the signal output end.

4. The switch parameter test circuit according to claim 2, characterized in that: The signal processing chip also includes a first power input terminal, a second power input terminal and a negative power input terminal; The first power input terminal is connected to a first power supply, and the first power supply provides a driving power supply for an internal logic circuit of the signal processing subunit through the first power input terminal; The second power input terminal is connected to a second power supply, and the second power supply provides a driving power supply to an internal driving circuit of the signal processing subunit through the second power input terminal; The negative power input terminal is connected to a negative power supply, and the negative power input terminal provides a negative power supply to an internal driving circuit of the signal processing subunit through the negative power input terminal, wherein a voltage of the second power supply is greater than a voltage of the negative power supply.

5. The switch parameter test circuit according to claim 4, characterized in that: The voltage of the first power supply is +5V; The voltage of the second power supply is 12V to 15V, and the voltage of the negative power supply is -5V to -2V.

6. The switch parameter test circuit according to claim 1, characterized in that: The switch parameter test circuit also includes a freewheeling and energy storage unit; The freewheeling and energy storage unit is connected to the second end of the acquisition unit, and the freewheeling and energy storage unit is used to provide energy storage and freewheeling current for the silicon carbide transistor to be tested.

7. The switch parameter test circuit according to claim 6, characterized in that: The freewheeling and energy storage unit includes a first inductor and a diode; One end of the first inductor is connected to the acquisition unit, and the other end is connected to a fourth power supply; The anode of the diode is connected to the acquisition unit, and the cathode of the diode is connected to the fourth power supply.

8. The switch parameter test circuit according to claim 2, characterized in that: The signal input unit includes a signal generator, the signal generator includes a signal output terminal and a first ground terminal, and the signal processing chip also includes a grounded second ground terminal; The signal output terminal is connected to the input terminal, and the first ground terminal is connected to the second ground terminal.

9. The switch parameter test circuit according to claim 2, characterized in that: The acquisition unit includes an oscilloscope.

10. The switch parameter test circuit according to claim 2, characterized in that: The signal processing chip includes a MAX22701E chip.

Images