CN219304817U - Dynamic driving circuit based on temperature characteristics of power semiconductor - Google Patents

Abstract

The utility model provides a dynamic driving circuit based on the temperature characteristic of a power semiconductor, which relates to the technical field of power semiconductor driving and comprises the following components: the signal receiving end of the first turn-off circuit is connected with the first signal output end of the micro control unit; the signal receiving end of the second turn-off circuit is connected with the second signal output end of the micro control unit; the output end of the power semiconductor is connected with the input end of the first turn-off circuit and the input end of the second turn-off circuit, and the input end of the power semiconductor is connected with the output end of the second turn-off circuit; and the signal output end of the temperature sampling circuit is connected with the signal receiving end of the micro control unit. The micro-control unit has the beneficial effects that when the temperature of the power semiconductor is larger than the temperature threshold value, the micro-control unit controls the first turn-off circuit and the second turn-off circuit to discharge simultaneously, so that the turn-off speed of the power semiconductor is accelerated, the working efficiency of a product is improved, and the power density of the product is improved.

Description

A Dynamic Driving Circuit Based on Temperature Characteristics of Power Semiconductors

technical field

The utility model relates to the technical field of power semiconductor drive, in particular to a dynamic drive circuit based on the temperature characteristics of the power semiconductor.

Background technique

For traditional power semiconductors, take the IGBT (Insulated Gate Bipolar Transistor) chip as an example below. The fixed driving resistance is used in the driving scheme, and the strong coupling relationship between the electrical characteristics of the IGBT and the temperature is not considered (the IGBT chip’s close relationship The turn-off speed has a negative temperature characteristic), as the temperature increases, the entire turn-off process of the IGBT slows down, the di/dt of the IGBT becomes smaller, and the tail current time of the IGBT is prolonged, resulting in an increase in turn-off loss, which is often limited by loss and Temperature causes underperformance of the device.

Utility model content

Aiming at the problems existing in the prior art, the utility model provides a dynamic drive circuit based on the temperature characteristics of power semiconductors, including:

A first shutdown circuit, the signal receiving end of the first shutdown circuit is connected to the first signal output terminal of the micro control unit;

a second shutdown circuit, the signal receiving end of the second shutdown circuit is connected to the second signal output terminal of the microcontroller unit;

A power semiconductor, the output terminal of the power semiconductor is connected to the input terminal of the first shutdown circuit and the input terminal of the second shutdown circuit, and the input terminal of the power semiconductor is connected to the output of the second shutdown circuit end;

A temperature sampling circuit, the signal output end of the temperature sampling circuit is connected to the signal receiving end of the micro control unit, the temperature sampling circuit is used to collect the temperature of the power semiconductor and send a temperature sampling signal, and the micro control unit according to The temperature sampling signal is processed to obtain the temperature of the power semiconductor.

Preferably, the first shutdown circuit includes:

An upper bridge drive chip, the first signal receiving end of the upper bridge drive chip is connected to the first signal output end of the micro control unit, the upper bridge drive unit is connected to an external power supply, and the upper bridge drive chip is grounded;

A first resistor, one end of the first resistor is connected to the first control terminal of the upper bridge driver chip;

A second resistor, one end of the second resistor is connected to the second control end of the upper bridge drive chip, the other end of the second resistor is connected to the other end of the first resistor and serves as the first shutdown circuit The input terminal is connected to the output terminal of the power semiconductor;

The first signal receiving end of the upper bridge driver chip is used as the signal receiving end of the first turn-off circuit.

Preferably, the signal output terminal of the temperature sampling circuit is connected to the signal receiving terminal of the micro control unit through the upper bridge driver chip.

Preferably, the temperature sampling circuit includes:

A thermosensitive sampling resistor, the thermosensitive sampling resistor is arranged on the power semiconductor, one end of the thermosensitive sampling resistor is connected to the first signal receiving end of the upper bridge driver chip and one end of the third resistor, the thermosensitive sampling resistor The other end of the sensitive sampling resistor is grounded, and the other end of the third resistor is connected to an external power supply;

The signal output end of the upper bridge driver chip is connected to the signal receiving end of the micro control unit.

One end of the thermistor sampling resistor is used as a signal output end of the temperature sampling circuit.

Preferably, the second shutdown circuit includes:

An isolation chip, the signal receiving end of the isolation chip is connected to the second signal output end of the micro control unit, the connection end of the isolation chip is connected to one end of the fourth resistor; the other end of the fourth resistor is connected to the fifth resistor One end of the fifth resistor, the other end of the fifth resistor is connected to the control terminal of the isolation chip, and the isolation chip is connected to an external power supply;

A field effect transistor, the gate of the field effect transistor is connected to the other end of the third resistor, the drain of the field effect transistor is connected to the input end of the first shutdown circuit, and the source of the field effect transistor Connect one end of the sixth resistor, the other end of the sixth resistor is connected to the input end of the power semiconductor and grounded;

The drain of the field effect transistor is used as the input terminal of the second shutdown circuit, the other end of the sixth resistor is used as the output terminal of the second shutdown circuit, and the second signal of the upper bridge driver chip is The receiving end serves as a signal receiving end of the second shutdown circuit.

Preferably, the field effect transistor is an N-channel field effect transistor.

Preferably, the power semiconductor is an IGBT chip, the G pole of the IGBT serves as the output terminal of the power semiconductor, and the E pole of the IGBT chip serves as the input terminal of the power semiconductor.

Preferably, the IGBT chip includes a gate capacitor, one end of the gate capacitor is connected to the G pole of the IGBT chip, and the other end of the gate capacitor is connected to the E pole of the IGBT chip.

The above technical solution has the following advantages or beneficial effects: the micro-control unit obtains the temperature of the power semiconductor based on the temperature sampling signal collected by the temperature sampling circuit; Discharge through the first shut-off circuit; when the temperature of the power semiconductor is high, the second shut-off circuit is controlled to conduct, so that the first shut-off circuit and the second shut-off circuit are discharged at the same time, which speeds up the shut-off speed of the power semiconductor and improves the product quality. High work efficiency, improve product power density.

Description of drawings

FIG. 1 is an electrical schematic diagram of a dynamic drive circuit based on the temperature characteristics of power semiconductors in a preferred embodiment of the present invention.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also belong to the category of the present invention as long as they conform to the gist of the present invention.

In a preferred embodiment of the present utility model, based on the above-mentioned problems existing in the prior art, a dynamic drive circuit based on the temperature characteristics of power semiconductors is now provided, as shown in Figure 1, including:

The first shutdown circuit 1, the signal receiving end of the first shutdown circuit 1 is connected to the first signal output terminal of the micro control unit 2;

The second shutdown circuit 3, the signal receiving end of the second shutdown circuit 3 is connected to the second signal output terminal of the microcontroller unit 2;

A power semiconductor 4, the output end of the power semiconductor 4 is connected to the input end of the first shut-off circuit 1 and the input end of the second shut-off circuit 3, and the input end of the power semiconductor 4 is connected to the output end of the second shut-off circuit 3;

A temperature sampling circuit 5, the signal output end of the temperature sampling circuit 5 is connected to the signal receiving end of the micro control unit 2, the temperature sampling circuit 5 is used to collect the temperature of the power semiconductor 4 and send a temperature sampling signal, and the micro control unit 2 processes the temperature sampling signal according to the temperature sampling circuit 5. The temperature of the power semiconductor 4 is obtained.

Specifically, in this embodiment, according to the shut-off requirement of the power semiconductor 4, the micro-control unit 2 controls the first shut-off circuit 1 to turn on, and shuts off the power semiconductor 4, and at the same time, the micro-control unit 2 collects data according to the temperature sampling circuit 5 The temperature sampling signal of the power semiconductor 4 is used to obtain the temperature of the power semiconductor 4. When the temperature of the power semiconductor 4 does not exceed the set temperature threshold, the micro-control unit controls the second shutdown circuit to close, and only discharges through the first shutdown circuit; when the power semiconductor 4 When the temperature exceeds the set temperature threshold, the second shut-off circuit 3 is turned on to realize simultaneous discharge through the first shut-off circuit 1 and the second shut-off circuit 3, speed up the shut-off speed of the power semiconductor 4, and reduce the power semiconductor 4 turn-off losses, improving efficiency.

In a preferred embodiment of the present utility model, as shown in FIG. 1 , the power semiconductor 4 is an IGBT chip, the G pole of the IGBT is used as the output end of the power semiconductor 4 , and the E pole of the IGBT chip is used as the input end of the power semiconductor 4 .

In a preferred embodiment of the present invention, as shown in Figure 1, the IGBT chip includes a gate capacitor C1, one end of the gate capacitor C1 is connected to the G pole of the IGBT chip, and the other end of the gate capacitor C1 is connected to the E pole of the IGBT chip. pole.

In a preferred embodiment of the present utility model, as shown in Figure 1, the first shutdown circuit 1 includes:

The upper bridge driver chip U1, the first signal receiving end of the upper bridge driver chip U1 is connected to the first signal output end of the micro control unit 2, the upper bridge driver chip U1 is connected to an external power supply, and the upper bridge driver chip U1 is grounded;

A first resistor R1, one end of the first resistor R1 is connected to the first control terminal of the upper bridge driver chip U1;

The second resistor R2, one end of the second resistor R2 is connected to the second control terminal of the upper bridge driver chip U1, and the other end of the second resistor R2 is connected to the other end of the first resistor R1 as the input end of the first shutdown circuit 1 the output terminal of the power semiconductor 4;

The first signal receiving end of the upper bridge driver chip U1 serves as the signal receiving end of the first turn-off circuit 1 .

Specifically, in this embodiment, as shown in FIG. 1 , the power semiconductor 4 takes an IGBT chip as an example, and the micro-control unit continuously sends out first control signals with different duty ratios to the upper bridge driver chip U1 according to the shutdown requirement. When the control signal is at a high level, the first control terminal of the upper bridge driver chip U1 outputs a high level, and the second control terminal is in a high-impedance state. At this time, the first shutdown circuit 1 is turned on, and the IGBT chip is discharged through the second resistor R2. The charge of the gate capacitor C1 is discharged through R2 until the gate voltage is lower than the IGBT threshold voltage; when the first control signal is low, the first control terminal of the upper bridge driver chip U1 is in a high-impedance state, and the second control terminal Output low level, at this time the first shutdown circuit is turned off.

In a preferred embodiment of the present invention, as shown in FIG. 1 , the signal output end of the temperature sampling circuit 5 is connected to the signal receiving end of the micro control unit 2 through the upper bridge driver chip U1 .

In a preferred embodiment of the present utility model, as shown in Figure 1, the temperature sampling circuit 5 includes:

The thermal sampling resistor NTC is arranged on the power semiconductor 4. One end of the thermal sampling resistor NTC is connected to the first signal receiving end of the upper bridge driver chip U1 and one end of the third resistor R3. The thermal sampling resistor NTC The other end of the third resistor R3 is connected to the external power supply;

The signal output end of the upper bridge driver chip U1 is connected to the signal receiving end of the micro control unit 2 .

One end of the thermistor sampling resistor NTC is used as the signal output end of the temperature sampling circuit 5 .

Specifically, in this embodiment, the upper bridge driver chip U1 calculates the resistance value of the thermistor sampling resistor NTC according to the current value of the temperature sampling circuit 5, and performs temperature calibration and fitting according to the resistance value of the thermistor sampling resistor NTC to obtain the power semiconductor The actual temperature of 4 is sent to the micro control unit 2, and the micro control unit 2 controls the second shutdown circuit 3 to be turned on when it judges that the actual temperature is greater than the preset temperature threshold. The invention points of the technical solution will not be repeated here.

In a preferred embodiment of the present utility model, the second shutdown circuit 3 includes:

The isolation chip U2, the signal receiving end of the isolation chip U2 is connected to the second signal output end of the micro control unit 2, the connection end of the isolation chip U2 is connected to one end of the fourth resistor R4; the other end of the fourth resistor R4 is connected to the fifth resistor R5 One end, the other end of the fifth resistor R5 is connected to the control end of the isolation chip U2, and the isolation chip U2 is connected to an external power supply;

Field effect transistor T1, the gate of field effect transistor T1 is connected to the other end of the third resistor R3, the drain of field effect transistor T1 is connected to the input end of the first shutdown circuit 1, and the source of field effect transistor T1 is connected to the sixth resistor One end of R6, the other end of the sixth resistor R6 is connected to the input end of the power semiconductor 4 and grounded;

The drain of the field effect transistor T1 is used as the input terminal of the second shutdown circuit 3, the other end of the sixth resistor R6 is used as the output terminal of the second shutdown circuit 3, and the second signal receiving terminal of the upper bridge driver chip U1 is used as the second Turn off the signal receiving end of the circuit 3 .

Specifically, in this embodiment, as shown in FIG. 1, the power semiconductor 4 takes an IGBT chip as an example, and the micro-control unit 2 continuously sends second control signals with different duty ratios to the second shutdown circuit 3. The micro-control unit 2 When it is detected that the temperature of the IGBT chip is lower than the temperature threshold, the second control signal is at a low level, the control terminal of the isolation chip U2 outputs a low level, and the gate of the field effect transistor T1 is pulled down, and the field effect transistor T1 is turned off at this time , that is, the second shutdown circuit 3 is turned off; when the micro-control unit 2 detects that the temperature of the IGBT chip is not less than the temperature threshold, the second control signal is at a high level, and the control terminal of the isolation chip U2 outputs a high level, and the FET The gate of T2 is pulled high, and the field effect transistor T1 is turned on, that is, the second turn-off circuit 3 is turned on. At this time, the gate capacitance C1 of the IGBT chip is discharged through the third resistor R3 and the sixth resistor R6 until the gate voltage is lower than IGBT threshold voltage, at this time, the equivalent resistance is similar to the parallel connection of the third resistor R3 and the sixth resistor R6, which is equivalent to reducing the resistance, accelerating the discharge speed of the power semiconductor 4, reducing the turn-off loss of the power semiconductor 4, and improving work efficiency .

Specifically, in a preferred embodiment of the present utility model, the micro control unit 2 preferably adopts a TMS320F28335 chip, or a TMS32F28069 chip; the upper bridge driver chip U1 adopts a UCC21750 chip, or a BF1181 chip; the isolation chip U2 adopts an ISO7710FQDRQ1 chip, or an NSI8210 chip .

In a preferred embodiment of the present invention, the field effect transistor T1 is an N-channel type field effect transistor.

The above are only preferred embodiments of the present utility model, and are not intended to limit the implementation and protection scope of the present utility model. For those skilled in the art, they should be able to realize that all equivalent replacements made by using this specification and the contents of the illustrations The solutions obtained with obvious changes shall all be included in the protection scope of the present utility model.

Claims (8)

1. A dynamic driving circuit based on a temperature characteristic of a power semiconductor, comprising:

the signal receiving end of the first turn-off circuit is connected with the first signal output end of the micro control unit;

the signal receiving end of the second turn-off circuit is connected with the second signal output end of the micro control unit;

the output end of the power semiconductor is connected with the input end of the first turn-off circuit and the input end of the second turn-off circuit, and the input end of the power semiconductor is connected with the output end of the second turn-off circuit;

the signal output end of the temperature sampling circuit is connected with the signal receiving end of the micro-control unit, the temperature sampling circuit is used for collecting the temperature of the power semiconductor and sending a temperature sampling signal, and the micro-control unit processes the temperature of the power semiconductor according to the temperature sampling signal.

2. The dynamic driving circuit of claim 1, wherein the first shutdown circuit comprises:

the upper bridge driving chip is connected with an external power supply, and is grounded;

one end of the first resistor is connected with a first control end of the upper bridge driving chip;

one end of the second resistor is connected with the second control end of the upper bridge driver chip, and the other end of the second resistor is connected with the other end of the first resistor and is used as the input end of the first turn-off circuit to be connected with the output end of the power semiconductor;

the first signal receiving end of the upper bridge driving chip is used as the signal receiving end of the first turn-off circuit.

3. The dynamic driving circuit according to claim 2, wherein the signal output end of the temperature sampling circuit is connected to the signal receiving end of the micro control unit through the upper bridge driving chip.

4. The dynamic driving circuit of claim 2, wherein the temperature sampling circuit comprises:

the thermal sampling resistor is arranged on the power semiconductor, one end of the thermal sampling resistor is connected with the first signal receiving end of the upper bridge driving chip and one end of the third resistor, the other end of the thermal sampling resistor is grounded, and the other end of the third resistor is connected with an external power supply;

the signal output end of the upper bridge driving chip is connected with the signal receiving end of the micro control unit;

one end of the thermosensitive sampling resistor is used as a signal output end of the temperature sampling circuit.

5. The dynamic driving circuit of claim 4, wherein the second shutdown circuit comprises:

the signal receiving end of the isolation chip is connected with the second signal output end of the micro control unit, and the wiring end of the isolation chip is connected with one end of the fourth resistor; the other end of the fourth resistor is connected with one end of a fifth resistor, the other end of the fifth resistor is connected with the control end of the isolation chip, and the isolation chip is connected with an external power supply;

the grid electrode of the field effect tube is connected with the other end of the third resistor, the drain electrode of the field effect tube is connected with the input end of the first turn-off circuit, the source electrode of the field effect tube is connected with one end of a sixth resistor, and the other end of the sixth resistor is connected with the input end of the power semiconductor and grounded;

the drain electrode of the field effect transistor is used as the input end of the second turn-off circuit, the other end of the sixth resistor is used as the output end of the second turn-off circuit, and the second signal receiving end of the upper bridge driving chip is used as the signal receiving end of the second turn-off circuit.

6. The dynamic driving circuit of claim 5, wherein the fet is an N-channel fet.

7. The dynamic driving circuit according to claim 1, wherein the power semiconductor is an IGBT chip, a G-pole of the IGBT is an output terminal of the power semiconductor, and an E-pole of the IGBT chip is an input terminal of the power semiconductor.

8. The dynamic driving circuit of claim 7, wherein the IGBT chip comprises a gate capacitance, one end of the gate capacitance is connected to a G pole of the IGBT chip, and the other end of the gate capacitance is connected to an E pole of the IGBT chip.

Images