CN212965269U - Single-pulse avalanche energy resistance test circuit for field effect transistor - Google Patents

Abstract

The utility model provides a field effect transistor monopulse avalanche resistance energy test circuit, a direct current power supply, a voltage stabilizing circuit, a circuit change-over switch, a variable capacitance array circuit, a field effect transistor circuit and a prompt circuit, wherein the direct current power supply is connected with the variable capacitance array circuit through a first switch to charge the variable capacitance array circuit, the circuit change-over switch comprises a first switch and a second switch, the variable capacitance array circuit is connected with the field effect transistor circuit to provide avalanche energy for the field effect transistor circuit, the prompt circuit is connected with the variable capacitance array circuit through the first switch to prompt whether the field effect transistor to be tested is in a short circuit state or not, the utility model provides a field effect transistor monopulse avalanche resistance energy test circuit, which can obtain the energy parameter of the field effect transistor through simple equipment, and the verification cost is reduced.

Description

Single-pulse avalanche energy resistance test circuit for field effect transistor

Technical Field

The utility model relates to a field effect transistor test field, in particular to field effect transistor anti monopulse avalanche energy test circuit.

Background

At present, field effect transistors of different brands are developed in domestic markets, due to the fact that production processes and design schemes of field effect transistors of different brands are different, electrical performance parameters are different, basic parameters of the field effect transistors can be directly tested before leaving factories, but single-pulse avalanche resistance energy parameters can only be tested in laboratories, parameter testing equipment is high in price, users who generally purchase the field effect transistors do not have the parameter verification equipment, and parameter verification cost is high.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides an anti monopulse avalanche energy test circuit of field effect transistor can obtain the avalanche energy parameter of field effect transistor through simple equipment, reduces and verifies the cost.

The circuit for testing the single-pulse avalanche resistance of the field effect transistor according to the embodiment of the utility model comprises a direct current power supply, a voltage stabilizing circuit, a circuit change-over switch, a variable capacitor array circuit, a field effect transistor circuit and a prompt circuit, the input end of the voltage stabilizing circuit is connected with the direct current power supply, the circuit change-over switch comprises a first switch and a second switch which are arranged in a linkage manner, the first switch and the second switch are in opposite open-close states, the direct current power supply is connected with the variable capacitor array circuit through the first switch, the DC power supply charges the variable capacitor array circuit in a closed state of the first switch, the FET circuit comprises a tested FET, the variable capacitor array circuit is connected with the tested FET in parallel to provide avalanche energy for the tested FET, the grid electrode of the tested field effect transistor is connected with the voltage stabilizing circuit through the second switch; the direct current power supply is connected with the grid electrode of the field effect transistor to be detected through the voltage stabilizing circuit and the second switch, the direct current power supply provides working voltage for the field effect transistor to be detected in the closed state of the second switch, and the prompting circuit is connected with the variable capacitor array circuit through the first switch to prompt whether the field effect transistor to be detected is in a short circuit state or not.

According to the utility model discloses an anti monopulse avalanche energy test circuit of field effect transistor has following beneficial effect at least: during the test, the variable capacitor array circuit provides avalanche energy for the field effect transistor to be tested, a user can test the avalanche energy parameter of the field effect transistor to be tested only by adjusting the energy stored in the variable capacitor array circuit, the prompt circuit can detect whether the field effect transistor to be tested is in a short-circuit state or not, the user only needs to control the circuit switch and the energy stored in the variable capacitor array circuit, and then the avalanche energy parameter of the field effect transistor to be tested is obtained according to the state of the prompt circuit.

According to some embodiments of the utility model, voltage stabilizing circuit includes first resistance, diode, first electric capacity and first zener diode, first resistance the diode with first electric capacity connects gradually and constitutes the series circuit, the series circuit with DC power supply is parallelly connected, first zener diode with first electric capacity is parallelly connected.

According to some embodiments of the present invention, the fet circuit further includes a second resistor and a third resistor, the second resistor being connected to the third resistor, and the gate of the fet being tested being connected to the connection point of the second resistor and the third resistor.

According to the utility model discloses a some embodiments, the suggestion circuit includes the fourth resistance and is used for judging according to the bulb length of shining the time whether the field effect transistor under test is in short circuit state's direct current bulb, the fourth resistance with direct current bulb is connected.

According to some embodiments of the invention, further comprising a second capacitor, the variable capacitor array circuit is comprised of a number of second capacitors connected in anti-parallel to provide different avalanche energies.

According to some embodiments of the utility model, the field effect transistor circuit still includes second zener diode, the source electrode of being surveyed the field effect transistor with second zener diode's positive pole is connected, second zener diode's negative pole with the drain electrode of being surveyed the field effect transistor is connected.

According to some embodiments of the utility model, still include the current sampling circuit, the current sampling circuit with the field effect transistor series connection under test.

According to some embodiments of the utility model, still include oscilloscope, oscilloscope includes current probe, current probe with current sampling circuit is connected.

According to some embodiments of the utility model, the oscilloscope still includes voltage probe, voltage probe with variable capacitance array circuit is parallelly connected in order to acquire variable capacitance array circuit's voltage.

According to some embodiments of the present invention, the dc power supply circuit can be based on the demand of the field effect transistor under test is in order to adjust the dc output voltage.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram of a fet anti-monopulse avalanche energy test circuit according to an embodiment of the present invention;

fig. 2 is a circuit diagram of a fet anti-monopulse avalanche energy test circuit according to an embodiment of the present invention.

Reference numerals:

the device comprises a direct current power supply 100, a voltage stabilizing circuit 101, a circuit switching switch 105, a variable capacitor array circuit 107, a field effect transistor circuit 106, a current sampling circuit 108, a current probe 109, a voltage probe 111, an oscilloscope 110, a first switch 104, a second switch 103, a prompting circuit 102, a first resistor R1, a diode D1, a first capacitor C1, a second capacitor C2, a first voltage stabilizing diode ZD1, a field effect transistor LET to be detected, a second resistor R2, a third resistor R3, a fourth resistor R4, a direct current bulb L1 and a second voltage stabilizing diode ZD 2.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by referring to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.

Referring to fig. 1-2, a fet anti-monopulse avalanche energy testing circuit according to an embodiment of the present invention includes a dc power supply 100, a voltage stabilizing circuit 101, a circuit switch 105, a variable capacitor array circuit 107, a fet circuit 106 and a cue circuit 102, an input terminal of the voltage stabilizing circuit 101 is connected to the dc power supply 100, the circuit switch 105 includes a first switch 104 and a second switch 103 which are arranged in a linkage, open and closed states of the first switch 104 and the second switch 103 are opposite, an input terminal of the first switch 104 is connected to the dc power supply 100, an input terminal of the second switch 103 is connected to an output terminal of the voltage stabilizing circuit 101, the dc power supply 100 is connected to the variable capacitor array circuit 107 through the first switch 104 and the variable capacitor array circuit 107 to charge the variable capacitor array circuit 107 in an avalanche closed state of the first switch 104, the variable capacitor array circuit 107 is connected in parallel to the fet circuit 106 to provide energy to the fet circuit 106, the field effect transistor circuit 106 comprises a tested field effect transistor LET, the grid electrode of the tested field effect transistor LET is connected with the voltage stabilizing circuit 101 through the second switch 103, the direct current power supply 100 is connected with the grid electrode of the tested field effect transistor LET through the voltage stabilizing circuit 101 and the second switch 103, the direct current power supply 100 provides working voltage for the tested field effect transistor LET under the closed state of the second switch 103, and the prompting circuit 102 is connected with the variable capacitor array circuit 107 through the first switch 104 to prompt whether the tested field effect transistor LET is in a short-circuit state or not.

In this embodiment, a user may first place a field effect transistor to be tested in the circuit, then adjust the energy stored in the variable capacitor array circuit 107, and observe whether the field effect transistor to be tested is short-circuited, if the field effect transistor to be tested is short-circuited, it indicates that the value of the energy stored in the variable capacitor array circuit 107 is the magnitude of the avalanche energy parameter of the field effect transistor, the first switch 104 and the second switch 103 are alternately connected, the first switch 104 is used to control the variable capacitor array circuit 107 to be charged, the second switch 103 is used to control the variable capacitor array circuit 107 to be discharged, and the two operations may not be performed simultaneously.

Further, the voltage stabilizing circuit 101 comprises a first resistor R1, a diode D1, a first capacitor C1 and a first zener diode ZD1, wherein the first resistor R1, the diode and the first capacitor C1 are sequentially connected to form a series circuit, the series circuit is connected in parallel with the dc power supply 100, and the first zener diode ZD1 is connected in parallel with the first capacitor C1.

In this embodiment, the voltage regulator circuit 101 is used to keep the output dc voltage constant when the input voltage fluctuates or the load changes, and when the input voltage fluctuates or the load changes in the circuit, the voltage of the load is not changed due to the unique current-voltage characteristic curve of the zener diode.

Further, the fet circuit 106 further includes a second resistor R2 and a third resistor R3, the second resistor R2 is connected to the third resistor R3, and the gate of the fet LET is connected to the connection point of the second resistor R2 and the third resistor R3.

In this embodiment, the second resistor R2 and the third resistor R3 form a voltage reduction circuit, so as to ensure that the fet LET to be tested can normally operate.

Further, the prompting circuit 102 includes a fourth resistor R4 and a dc light bulb L1 for determining whether the fet LET is in a short circuit state according to the length of the light bulb lighting time, and the fourth resistor R4 is connected to the dc light bulb L1.

In this embodiment, the charging time required by the variable capacitor array circuit 107 is very short, that is, the time for the dc lamp L1 to illuminate is very short, and if the fet LET is short-circuited, the variable capacitor array circuit 107 cannot be charged, which indicates that the energy value stored in the variable capacitor array circuit 107 is the value of the avalanche energy parameter of the fet LET.

Further, the variable capacitance array circuit 107 is arranged in an anti-parallel configuration to provide different avalanche energies.

In this embodiment, the variable capacitor array circuit 107 is formed by connecting one second capacitor C2 or several second capacitors C2 in anti-parallel, so that the energy stored in the variable capacitor array circuit 107 can be changed according to the requirement.

Further, the testing device comprises a current sampling circuit 108, wherein the current sampling circuit 108 is connected with the drain electrode of the tested field effect transistor LET.

Further, the oscilloscope 110 is further included, the oscilloscope 110 includes a current probe 109 and a voltage probe 111, the current probe 109 is connected with the current sampling circuit 108, and the voltage probe 111 is connected in parallel with the variable capacitor array circuit 107 to obtain the voltage of the variable capacitor array circuit 107.

In this embodiment, when the current probe 109 detects that the current increases when the variable capacitor array circuit 107 is charged, or the voltage probe 111 detects that the voltage is 0 when the variable capacitor array circuit 107 is charged, it can be said that the fet LET is in a short circuit state, and the current probe 109 and the voltage probe 111 can simultaneously perform the function of observing whether the circuit is operating normally.

Further, the dc power supply 100 circuit can adjust the dc output voltage according to the requirements of the fet LET to be tested.

Further, the fet circuit 106 further includes a second zener diode ZD2, the source of the fet LET to be tested is connected to the anode of the second zener diode ZD2, and the cathode of the second zener diode ZD2 is connected to the drain of the fet LET to be tested.

While the preferred embodiments of the present invention have been described, the present invention is not limited to the above embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and such equivalent modifications or substitutions are intended to be included within the scope of the present invention as defined by the appended claims.

Claims (10)

1. A field effect transistor single pulse avalanche resistance energy test circuit is characterized by comprising:

a direct current power supply;

the input end of the voltage stabilizing circuit is connected with the direct-current power supply;

the circuit change-over switch comprises a first switch and a second switch which are arranged in a linkage manner, and the opening and closing states of the first switch and the second switch are opposite;

the direct current power supply is connected with the variable capacitor array circuit through the first switch, and the direct current power supply charges the variable capacitor array circuit in a closed state of the first switch;

the field effect transistor circuit comprises a tested field effect transistor, the variable capacitor array circuit is connected with the tested field effect transistor in parallel to provide avalanche energy for the tested field effect transistor, and the grid electrode of the tested field effect transistor is connected with the voltage stabilizing circuit through the second switch; the direct current power supply is connected with the grid electrode of the field effect transistor to be tested through the voltage stabilizing circuit and the second switch, and the direct current power supply provides working voltage for the field effect transistor to be tested when the second switch is in a closed state;

and the prompting circuit is connected with the variable capacitor array circuit through the first switch to prompt whether the field effect transistor to be tested is in a short-circuit state or not.

2. The FET energy against monopulse avalanche as claimed in claim 1, wherein said voltage regulator circuit includes a first resistor, a diode, a first capacitor and a first zener diode, said first resistor, said diode and said first capacitor being connected in series to form a series circuit, said series circuit being connected in parallel with said DC power supply, said first zener diode being connected in parallel with said first capacitor.

3. The fet resistance to monopulse avalanche energy testing circuit according to claim 1, wherein said fet circuit further comprises a second resistor and a third resistor, said second resistor and said third resistor being connected, and wherein the gate of said fet under test is connected to the junction of said second resistor and said third resistor.

4. The FET energy against monopulse avalanche energy testing circuit as claimed in claim 1, wherein said prompting circuit includes a fourth resistor and a DC bulb for determining whether said FET is in a short circuit state according to the length of the bulb lighting time, said fourth resistor being connected to said DC bulb.

5. The FET resistance to monopulse avalanche energy test circuit of claim 1, further comprising a second capacitor, wherein said variable capacitor array circuit is comprised of a plurality of second capacitors connected in anti-parallel to provide different avalanche energies.

6. The FET energy immunity to monopulse avalanche energy test circuit of claim 1, further comprising a second Zener diode, wherein the source of the FET under test is connected to the anode of the second Zener diode, and the cathode of the second Zener diode is connected to the drain of the FET under test.

7. The FET resistance to monopulse avalanche energy testing circuit of claim 1, further comprising a current sampling circuit, said current sampling circuit being connected in series with said FET under test.

8. The FET resistance to monopulse avalanche energy testing circuit according to claim 7, further comprising an oscilloscope, said oscilloscope comprising a current probe, said current probe being connected to said current sampling circuit.

9. The fet unimpaired avalanche energy testing circuit of claim 8, wherein the oscilloscope further comprises a voltage probe, the voltage probe being connected in parallel with the variable capacitor array circuit to obtain the voltage of the variable capacitor array circuit.

10. The FET avalanche energy immunity test circuit of claim 1, wherein the DC power supply circuit can regulate the DC output voltage according to the requirements of the FET under test.

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