CN118138027A - A compatible driving circuit and device for silicon carbide MOS tube - Google Patents

Abstract

The application relates to the technical field of MOS tube driving, in particular to a compatible driving circuit and equipment of a silicon carbide MOS tube, wherein the circuit comprises a square wave generating module, an isolation boosting module, a rectifying module, a voltage regulating output module and an isolation voltage regulating module, wherein the square wave generating module is used for acquiring PWM signals sent by an external singlechip and converting the square wave signals into power square wave signals, the isolation boosting module is used for boosting the power square wave signals into high-voltage square wave signals, the rectifying module is used for rectifying the high-voltage square wave signals into high-voltage direct current signals, the voltage regulating output module is used for regulating the high-voltage direct current signals into first driving voltages and outputting the first driving voltages to a load, the isolation voltage regulating module is used for acquiring the voltage regulating signals sent by the singlechip and regulating the first driving voltages into second driving voltages according to the voltage regulating signals, and the compatible driving voltages are conveniently supplied for different types of silicon carbide MOS tubes.

Description

A compatible driving circuit and device for silicon carbide MOS tube

Technical Field

The present application relates to the technical field of MOS tube driving, and in particular to a compatible driving circuit and device for a silicon carbide MOS tube.

Background technique

Compared with traditional silicon MOS tubes, silicon carbide MOS tubes have the advantages of greatly reduced on-resistance and switching loss and are suitable for higher operating frequencies. However, due to the different production technology solutions of various manufacturers, the driving voltages of silicon carbide MOS tubes produced by various manufacturers are also different. The driving voltages of major manufacturers are mainly concentrated in "-3V to +15V" and "-4V to 18V". In order to adapt to different types of silicon carbide MOS tubes, the output voltage is currently mainly adjusted by changing the ratio of the drive transformer or adjusting the output sampling loop. These two methods usually require changing the layout of the BOM (Bill of Material) or PCB (Printed Circuit Board), resulting in cumbersome operations to replace different types of silicon carbide MOS tubes.

Therefore, how to conveniently supply suitable driving voltage for different types of silicon carbide MOS tubes is a technical problem that needs to be solved urgently.

Summary of the invention

The purpose of this application is to conveniently supply adaptive driving voltages for different types of silicon carbide MOS tubes.

The above technical objectives of this application are achieved through the following technical solutions:

A compatible driving circuit for a silicon carbide MOS tube comprises a square wave generating module, an isolated voltage boosting module, a rectifying module, a voltage regulating output module and an isolated voltage regulating module;

The square wave generating module is used to obtain the PWM signal sent by the external single-chip microcomputer and convert the PWM signal into a power square wave signal, and includes an input end and an output end. The input end of the square wave generating module is connected to the single-chip microcomputer, and the output end of the square wave generating module is used to output the converted power square wave signal.

The isolation boost module is used to boost the power square wave signal into a high-voltage square wave signal, and the rectifier module is used to rectify the high-voltage square wave signal into a high-voltage DC signal, and the rectifier module includes a first rectifier unit and a second rectifier unit;

The first rectifier unit and the second rectifier unit each include an input end and an output end;

The isolated boost module comprises an input end and two output ends, the input end of the isolated boost module is connected to the output end of the square wave generating module, the first output end of the isolated boost module is connected to the input end of the first rectifier unit, and the second output end of the isolated boost module is connected to the input end of the second rectifier unit;

The voltage regulating output module is used to adjust the high-voltage DC signal to a first driving voltage suitable for a first silicon carbide MOS tube, and output the first driving voltage to the first silicon carbide MOS tube, wherein the first silicon carbide MOS tube includes a first MOS upper tube and a first MOS lower tube;

The voltage regulating output module comprises an upper tube output unit and a lower tube output unit, and each of the upper tube output unit and the lower tube output unit comprises an input end, an output end and a voltage regulating end;

The input end of the upper tube output unit is connected to the output end of the first rectifier unit, and is used to receive the high-voltage DC signal output by the first rectifier unit. The output end of the upper tube output unit is used to adjust the high-voltage DC signal to a DC signal suitable for the first MOS upper tube and output it to the upper tube.

The input end of the lower tube output unit is connected to the output end of the second rectifier unit, and is used to receive the high-voltage DC signal output by the second rectifier unit. The output end of the lower tube output unit is used to adjust the high-voltage DC signal to a DC signal suitable for the first MOS lower tube and output it to the lower tube.

The isolation voltage regulation module is used to obtain the voltage regulation signal sent by the single-chip computer, and adjust the first driving voltage to a second driving voltage according to the voltage regulation signal, and output the second driving voltage to a second silicon carbide MOS tube through the voltage regulation output module, wherein the second silicon carbide MOS tube includes a second MOS upper tube and a second MOS lower tube;

The isolated voltage regulating module comprises a first voltage regulating unit and a second voltage regulating unit, wherein the first voltage regulating unit and the second voltage regulating unit each comprise an input end and an output end;

The first voltage regulating unit is used to adjust the applicable DC signal of the first MOS upper tube to the applicable DC signal of the second MOS upper tube, the input end of the first voltage regulating unit is used to obtain the voltage regulating signal, and the output end of the first voltage regulating unit is connected to the voltage regulating end of the upper tube output unit;

The second voltage regulating unit is used to adjust the applicable DC signal of the first MOS lower tube to the applicable DC signal of the second MOS lower tube, the input end of the second voltage regulating unit is used to obtain the voltage regulating signal, and the output end of the second voltage regulating unit is connected to the voltage regulating end of the lower tube output unit.

By adopting the above technical solution, when the single-chip microcomputer does not send a voltage regulation signal, the first output unit will output the first driving voltage to the upper tube of the silicon carbide MOS, and the second output unit will output the first driving voltage to the lower tube of the silicon carbide MOS; when the single-chip microcomputer sends a voltage regulation signal, the first output unit will output the second driving voltage to the upper tube of the silicon carbide MOS, and the second output unit will output the second driving voltage to the lower tube of the silicon carbide MOS, thereby conveniently adapting to the driving voltages required by two different types of silicon carbide MOS tubes.

Optionally, the square wave generating module includes a first resistor, a second resistor and a power square wave generator;

The power square wave generator comprises a first square wave receiving end, a second square wave receiving end, a first power square wave output end and a second power square wave output end;

One end of the first resistor is connected to the single chip microcomputer, and the other end is connected to the first square wave receiving end, and the first power square wave output end is connected to the input end of the isolation boost transformer;

One end of the second resistor is connected to the single chip microcomputer, and the other end is connected to the second square wave receiving end. The second power square wave output end is connected to the input end of the isolation boost module.

By adopting the above technical solution, the PWM signal sent by the single-chip microcomputer is converted into a power square wave signal of a specific power, which can cooperate with the isolated boost module to output power.

Optionally, the square wave generating module further includes a first capacitor and a second capacitor;

One end of the first capacitor is connected to the connection between the first resistor and the first square wave receiving end, and the other end is grounded; one end of the second capacitor is connected to the connection between the second resistor and the second square wave receiving end, and the other end is grounded.

By adopting the above technical solution, the interference signal can be grounded and filtered out, signal interference can be eliminated, and signal stability can be improved.

Optionally, the isolation boost module includes a transformer, and the transformer includes a primary winding, a first secondary winding, and a second secondary winding;

One end of the primary winding is connected to the first power square wave output end, and the other end is connected to the second power square wave output end; one end of the first secondary winding is connected to the output end of the first rectifier unit, and the other end is connected to the input end of the first rectifier unit;

One end of the second secondary winding is connected to the output end of the second rectifier unit, and the other end is connected to the input end of the second rectifier unit.

By adopting the above technical solution, the power square wave signal is boosted into a high-voltage square wave signal through a transformer, which facilitates signal transmission.

Optionally, the isolated boost module further includes a third capacitor; the third capacitor is connected in series between the first power square wave output end and one end of the primary winding.

By adopting the above technical solution, the capacitor can suppress high-frequency signals, reduce signal interference, and maintain stable signal transmission.

Optionally, the first rectifying unit includes a first diode, a second diode, a third diode and a fourth diode, and the second rectifying unit includes a fifth diode, a sixth diode, a seventh diode and an eighth diode;

The positive electrode of the first diode is connected to one end of the first secondary winding and the negative electrode of the second diode, the negative electrode of the first diode is connected to the input end of the upper tube output unit, and the positive electrode of the second diode is connected to the first negative voltage output end; the positive electrode of the third diode is connected to the other end of the first secondary winding and the negative electrode of the fourth diode, and the negative electrode of the fourth diode is connected to the first negative voltage output end.

By adopting the above technical solution, the high-voltage square wave signals outputted from the two output ends of the isolation boost module are subjected to full-bridge rectification to generate high-voltage DC signals.

Optionally, the upper tube output unit includes a first signal controller, a third resistor, a fourth resistor and a fifth resistor, and the first signal controller includes an input end and an output end;

The input end of the first signal controller is connected to the cathodes of the first diode and the third diode, and is used to receive the first high-voltage DC signal rectified by the first rectifying unit, and the output end of the first signal controller is connected to one end of the third resistor and the first positive voltage output end;

The other end of the third resistor is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the first negative voltage output end;

The lower tube output unit includes a second signal controller, a sixth resistor, a seventh resistor and an eighth resistor, and the second signal controller includes an input end and an output end;

The input end of the second signal controller is connected to the cathodes of the fifth diode and the sixth diode, and is used to receive the second high-voltage DC signal rectified by the second rectifying unit, and the output end of the second signal controller is connected to one end of the sixth resistor and the second positive voltage output end;

The other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to one end of the eighth resistor, and the other end of the eighth resistor is connected to the second negative voltage output terminal.

By adopting the above technical solution, the high-voltage DC signals output by the first rectifier unit and the second rectifier unit are divided respectively, and the output total voltage and positive and negative voltages are adjusted by the resistance value of each resistor to adapt a driving voltage of a silicon carbide MOS tube.

Optionally, the upper tube output unit further includes a first operational amplifier, and the lower tube output unit further includes a second operational amplifier;

The positive phase input terminal of the first operational amplifier is connected to the connection point of the third resistor and the fourth resistor, the negative phase input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier is grounded;

The positive phase input terminal of the second operational amplifier is connected to the connection point of the sixth resistor and the seventh resistor, the negative phase input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the second operational amplifier is grounded.

By adopting the above technical solution, the ground signal is constructed through the operational amplifier to keep the ground terminal signal stable. If the voltage is directly output to the ground, it will affect the feedback amount and cause the output voltage to change.

Optionally, the first voltage regulating unit includes a first transistor, a first photocoupler and a ninth resistor; the first photocoupler includes a first photodiode and a first phototransistor;

The base of the first transistor is connected to the single chip microcomputer for receiving the voltage regulation signal, the collector is connected to the cathode of the first photodiode, and the emitter is grounded;

The anode of the first photodiode is connected to an external level signal source, the collector of the first phototransistor is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to the connection point of the fourth resistor and the fifth resistor, and the emitter of the first phototransistor is connected to the first negative voltage output end and the other end of the fifth resistor;

The second voltage regulating unit includes a second triode, a second photocoupler and a tenth resistor; the second photocoupler includes a second photodiode and a second phototriode;

The base of the second transistor is connected to the single chip microcomputer for receiving the voltage regulation signal, the collector is connected to the cathode of the second photodiode, and the emitter is grounded;

The positive electrode of the second photodiode is connected to an external level signal source, the collector of the second phototransistor is connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the connection between the seventh resistor and the eighth resistor, and the emitter of the second phototransistor is connected to the second negative voltage output end and the other end of the eighth resistor.

By adopting the above technical solution, the first voltage regulating unit and the second voltage regulating unit can receive the voltage regulating signal sent by the single chip microcomputer, thereby respectively changing the resistance values of the first output unit and the second output unit, so that the driving voltage output to the upper and lower tubes of the silicon carbide MOS changes to adapt to the driving voltage requirements of another silicon carbide MOS tube.

On the other hand, the present application discloses a device, which internally includes a circuit structure of a compatible driving circuit of the above-mentioned silicon carbide MOS tube.

In summary, the present application includes at least one of the following beneficial effects:

1. When the single-chip microcomputer does not send a voltage regulation signal, the first output unit will output the first driving voltage to the upper tube of the silicon carbide MOS, and the second output unit will output the first driving voltage to the lower tube of the silicon carbide MOS; when the single-chip microcomputer sends a voltage regulation signal, the first output unit will output the second driving voltage to the upper tube of the silicon carbide MOS, and the second output unit will output the second driving voltage to the lower tube of the silicon carbide MOS, thereby conveniently adapting to the driving voltages required by two different types of silicon carbide MOS tubes.

2. The first operational amplifier and the second operational amplifier are grounded, and the ground signal is constructed through two first-stage operational amplifiers, so that the voltage output to the ground remains stable, preventing the signal feedback amount from changing due to the load effect of the direct grounding output, resulting in fluctuations in the output voltage.

3. By adjusting the resistance values of the resistors in the first output unit, the second output unit, the first voltage regulating unit and the second voltage regulating unit, the total voltage and the positive and negative voltages output to the load can be adjusted, wherein the total voltage is used to drive the silicon carbide MOS tube. Since the driving voltage threshold of the silicon carbide MOS tube is low, it is not easy to shut down at 0 voltage, and negative voltage is usually used for shutdown. Therefore, it is also necessary to adjust the positive and negative voltages and use negative voltage to shut down.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a module connection diagram of an embodiment of a compatible driving circuit of a silicon carbide MOS tube of the present application;

FIG. 2 is a circuit schematic diagram of an embodiment of a compatible driving circuit of a silicon carbide MOS tube of the present application.

Detailed ways

The present application is further described in detail below in conjunction with the accompanying drawings.

Referring to Figure 1, Figure 1 is a module connection diagram of an embodiment of a compatible driving circuit of a silicon carbide MOS tube of the present application, including a square wave generating module 1, an isolated boost module 2, a rectifier module 3, a voltage regulating output module 4 and an isolated voltage regulating module 5.

The square wave generating module 1 is used to obtain the PWM signal sent by the external single-chip microcomputer and convert the square wave signal into a power square wave signal. It includes an input end and an output end. The input end of the square wave generating module 1 is connected to the single-chip microcomputer, and the output end of the square wave generating module 1 is used to output the converted power square wave signal.

About the square wave generating module 1: The square wave generating module contains a square wave generator, which can convert the received square wave signal into a power square wave signal of a specific power level, thereby stably outputting a square wave signal of a certain power. In the embodiment of the present application, the driver chip FAN3224, which is generally used to drive MOS tubes, is used as a power square wave generator, and cooperates with the isolation boost module 2 to output a high-voltage square wave signal of a certain power. FAN3224 is only an optional embodiment and should not limit the selection of the square wave generator. The square wave generator based on the same concept should be considered to be within the protection scope of the present application.

The isolation boost module 2 is used to boost the power square wave signal into a high-voltage square wave signal, and the rectifier module 3 is used to rectify the high-voltage square wave signal into a high-voltage DC signal. The rectifier module 3 includes a first rectifier unit 31 and a second rectifier unit 32;

The first rectifier unit 31 and the second rectifier unit 32 each include an input end and an output end;

The isolation boost module 2 includes an input end and two output ends. The input end of the isolation boost module 2 is connected to the output end of the square wave generating module 1, the first output end of the isolation boost module 2 is connected to the input end of the first rectifier unit 31, and the second output end of the isolation boost module 2 is connected to the input end of the second rectifier unit 32.

About the isolation boost module 2: The isolation boost module 2 contains a transformer for isolation boosting, and the transformer includes at least one primary winding and two secondary windings, wherein the induced electromotive force generated at both ends of the primary winding can be induced at both ends of the first secondary winding and the second secondary winding, wherein the first secondary winding outputs a high-voltage square wave signal to the first rectifier unit 31 and the second secondary winding to the second rectifier unit 32, thereby isolating the AC signal transmission, and at the same time, the signal boosting effect is achieved through the winding turns ratio.

Regarding the rectifier module 3: The rectifier module 3 contains two rectifier units, each of which contains multiple diodes, and the multiple diodes are connected in combination to form a rectifier bridge. In this embodiment, the first rectifier unit 31 converts the high-voltage square wave signal induced by the first secondary winding into a high-voltage DC signal through full-bridge rectification, and the second rectifier unit 32 converts the high-voltage square wave signal induced by the second secondary winding into a high-voltage DC signal through full-bridge rectification.

The voltage regulating output module 4 is used to adjust the high voltage DC signal to a first driving voltage suitable for a first silicon carbide MOS tube, and output the first driving voltage to the first silicon carbide MOS tube, wherein the first silicon carbide MOS tube includes a first MOS upper tube and a first MOS lower tube;

The voltage regulating output module 4 includes an upper tube output unit 41 and a lower tube output unit 42, and each of the upper tube output unit 41 and the lower tube output unit 42 includes an input end, an output end and a voltage regulating end;

The input end of the upper tube output unit 41 is connected to the output end of the first rectifier unit 31, and is used to receive the high-voltage DC signal output by the first rectifier unit 31. The output end of the upper tube output unit 41 is used to adjust the high-voltage DC signal to a DC signal suitable for the first MOS upper tube and output it to the upper tube;

The input end of the lower tube output unit 42 is connected to the output end of the second rectifier unit 32, and is used to receive the high-voltage DC signal output by the second rectifier unit 32. The output end of the lower tube output unit 42 is used to adjust the high-voltage DC signal to a suitable DC signal for the first MOS lower tube and output it to the lower tube.

Regarding the voltage regulating output module 4: the voltage regulating output module 4 contains an upper tube output unit 41 and a lower tube output unit 42, the upper tube output unit 41 provides a driving voltage for the upper tube of a silicon carbide MOS tube driven by a half-bridge, and the lower tube output unit 42 provides a driving voltage for the lower tube of the same silicon carbide MOS tube driven by a half-bridge, and the upper tube output unit 41 and the lower tube output unit 42 each contain a signal controller and multiple resistors, wherein the first signal controller can output a high-voltage DC signal rectified by the first rectifying unit 31 when the isolation voltage regulator 5 does not receive the single-chip microcomputer, and the high-voltage DC signal is divided by multiple resistors in the upper tube output unit 41 to form a positive and negative voltage; similarly, the second signal controller can output a high-voltage DC signal rectified by the second rectifying unit 32 when the isolation voltage regulator 5 does not receive the single-chip microcomputer, and the high-voltage DC signal is divided by multiple resistors in the upper tube output unit 42.

The isolation voltage regulation module 5 is used to obtain the voltage regulation signal sent by the single chip computer, and adjust the first driving voltage to a second driving voltage suitable for a second silicon carbide MOS tube according to the voltage regulation signal, wherein the second silicon carbide MOS tube includes a second MOS upper tube and a second MOS lower tube;

The isolation voltage regulating module 5 includes a first voltage regulating unit 51 and a second voltage regulating unit 52, wherein the first voltage regulating unit 51 and the second voltage regulating unit 52 each include an input end and an output end;

The first voltage regulating unit 51 is used to adjust the applicable DC signal of the first MOS upper tube to the applicable DC signal of the second MOS upper tube, the input end of the first voltage regulating unit 51 is used to obtain the voltage regulating signal, and the output end of the first voltage regulating unit 51 is connected to the voltage regulating end of the upper tube output unit 41;

The second voltage regulating unit 52 is used to adjust the applicable DC signal of the first MOS lower tube to the applicable DC signal of the second MOS lower tube, the input end of the second voltage regulating unit 52 is used to obtain the voltage regulating signal, and the output end of the second voltage regulating unit 52 is connected to the voltage regulating end of the lower tube output unit 42.

About the isolation voltage regulation module 5: The isolation voltage regulation module 5 contains a first voltage regulation unit 51 and a second voltage regulation unit 52, each of which contains a photoelectric coupler and a resistor. Among them, the first voltage regulation unit 51 is connected to the upper tube output unit 41. When the voltage regulation signal triggers the photoelectric coupler in the first voltage regulation unit 51, the voltage regulation end of the signal controller in the upper tube output unit 41 is opened through the passage of the first voltage regulation unit 51, so that the resistor in 51 is incorporated into the upper tube output unit 41, and the resistance value of 41 is changed, so that the total voltage and positive and negative voltage output to the upper tube change. Among them, the voltage regulation signal is a high and low level signal. When the single chip sends a high level, the transistors in the first voltage regulation unit 51 and the second voltage regulation unit 52 will be triggered, thereby turning on the photoelectric coupler in the unit.

Similarly, the second voltage regulating unit 52 is connected to the lower tube output unit 42. When the voltage regulating signal triggers the photoelectric coupler in the second voltage regulating unit 52, the voltage regulating end of the signal controller in the lower tube output unit 42 is opened through the passage of the second voltage regulating unit 52, so that the resistor in 52 is incorporated into the upper tube output unit 42, and the resistance value of 42 is changed, so that the total voltage and the positive and negative voltages output to the lower tube change.

Based on the module connection diagram of the compatible driving circuit of the silicon carbide MOS tube, the circuit connection of an embodiment of the present application is specifically described, with reference to Figure 2, which is a circuit schematic diagram of an embodiment of the compatible driving circuit of the silicon carbide MOS tube of the present application.

In the embodiment of the present application, the square wave generating module 1 includes a first resistor R1, a second resistor R2 and a power square wave generator U1;

The power square wave generator U1 includes a first square wave receiving terminal INA, a second square wave receiving terminal INB, a first power square wave output terminal OUTA and a second power square wave output terminal OUTB;

One end of the first resistor R1 is connected to the single chip microcomputer, and the other end is connected to the first square wave receiving end, and the first power square wave output end is connected to the input end of the isolation boost transformer T1;

One end of the second resistor R2 is connected to the single chip microcomputer, and the other end is connected to the second square wave receiving end. The second power square wave output end is connected to the input end of the isolation boost module.

Specifically, the PWM signal sent by the single-chip microcomputer is controlled to have two complementary duty cycles, while retaining a certain dead time to prevent the upper and lower tubes of the silicon carbide MOS tube from being turned on at the same time due to signal transmission delay. The first resistor R1 divides the voltage of the first input port of the PWM signal, and the second resistor R2 divides the voltage of the second input port of the PWM signal to prevent short circuit. The external level signal VCC provides a DC signal for the first power square wave enable port ENA, the second power square wave enable port ENB and the device power supply port VDD of the power square wave generator U1.

More specifically, the PWM signal sent by the single-chip microcomputer is input from the first square wave receiving terminal INA and the second square wave receiving terminal INB of the power square wave generator U1 respectively. After the INA port receives the PWM signal, it is powered by the DC signal received by the port ENA to generate a power square wave signal of a specific power and output from the OUTA port; similarly, the INB port is powered by the DC signal received by the port ENA to generate a power square wave signal of a specific power and output from the OUTB port. The output of U1 is a complementary square wave of the amplitude of VCC. In the embodiment of the present application, VCC is set to 12V. The square wave generating module 1 can also add a capacitor to eliminate interference signals, which is explained in detail below:

The square wave generating module 1 further includes a first capacitor C1 and a second capacitor C2;

One end of the first capacitor C1 is connected to the connection point between the first resistor R1 and the first square wave receiving terminal INA, and the other end is grounded.

Specifically, the PWM signal input from the single chip to the first square wave receiving terminal INA is filtered so that the interference signal is discharged through the ground, thereby increasing the stability of the signal.

One end of the second capacitor C2 is connected to the connection point between the second resistor R2 and the second square wave receiving terminal INB, and the other end is grounded.

Specifically, the PWM signal input from the single chip microcomputer to the second square wave receiving terminal INB is filtered so that the interference signal is discharged through the ground, thereby increasing the stability of the signal.

The power square wave signal generated by the power square wave generator U1 is output to the isolation boost module 2. The isolation boost module 2 is described in detail below:

The isolation boost module 2 includes a transformer T1, and the transformer T1 includes a primary winding, a first secondary winding, and a second secondary winding;

One end of the primary winding is connected to the first power square wave output terminal OUTA, and the other end is connected to the second power square wave output terminal OUTB;

One end of the first secondary winding is connected to the output end of the first rectifier unit 31, and the other end is connected to the input end of the first rectifier unit 31;

One end of the second secondary winding is connected to the output end of the second rectifying unit 32 , and the other end of the second secondary winding is connected to the input end of the second rectifying unit 32 .

Specifically, the power square wave signal will generate a positive and a negative induced electromotive force at both ends of the primary winding of the transformer T1. The first secondary winding and the second secondary winding will induce the electromotive force accordingly to generate a power square wave signal, forming an isolated transmission. The power square wave signal can be boosted by changing the turns ratio of the primary winding and the secondary winding. In an embodiment of the present application, the transformation ratio of the transformer T1 is set to 1:2, that is, the high-voltage square wave signal after the boost is twice the voltage value of the signal source VCC. Assuming that VCC is 12V, a 24V high-voltage square wave signal will be output to the rectifier module 3. In addition, one end of the primary winding can also be subjected to voltage stabilization processing, and the voltage stabilization processing is specifically described below:

The isolation boost module 3 further includes a third capacitor C3; the third capacitor C3 is connected in series between the first power square wave output terminal OUTA and one end of the primary winding.

Specifically, the series capacitor C3 at one end of the primary winding of the transformer T1 can stabilize the square wave signal to prevent the signal from being instantly large enough to damage the circuit. The capacitor C3 can also be connected in series between the second power square wave output terminal OUTB and the other end of the primary winding to achieve the same effect.

More specifically, the high-voltage square wave signal generated by the first secondary winding is output to the first rectifier unit 31 for rectification, and the high-voltage square wave signal generated by the second secondary winding is output to the second rectifier unit 32 for rectification. The signal rectification part is specifically described below:

The first rectifying unit 31 includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4, and the second rectifying unit 32 includes a fifth diode D5, a sixth diode D6, a seventh diode D7 and an eighth diode D8;

The anode of the first diode D1 is connected to one end of the first secondary winding and the cathode of the second diode D2, the cathode of the first diode D1 is connected to the input end of the upper tube output unit 41, and the anode of the second diode D2 is connected to the first negative voltage output end VOUT1-;

An anode of the third diode D3 is connected to the other end of the first secondary winding and a cathode of the fourth diode D4 , and the cathode of the fourth diode D4 is connected to the first negative voltage output terminal VOUT1 −.

Specifically, diodes D1, D2, D3 and D4 form a full-bridge rectifier to construct positive and negative DC voltages, outputting negative voltage to the VOUT1- port and positive voltage to the up-tube output unit 41. In the embodiment of the present application, the amplitude of the high-voltage square wave signal is 24V, and the DC signal formed by rectification is also 24V.

The anode of the fifth diode D5 is connected to one end of the second secondary winding and the cathode of the sixth diode D6, the cathode of the fifth diode D5 is connected to the input end of the lower tube output unit 42, and the anode of the sixth diode D6 is connected to the second negative voltage output end VOUT2-;

An anode of the seventh diode D7 is connected to the other end of the second secondary winding and a cathode of the eighth diode D8, and the cathode of the eighth diode D8 is connected to the second negative voltage output terminal VOUT2-.

Specifically, diodes D5, D6, D7 and D8 form a full-bridge rectifier to construct positive and negative voltages, outputting negative voltage to the VOUT2- port and positive voltage to the lower tube output unit 42. In the embodiment of the present application, the amplitude of the high-voltage square wave signal is 24V, and the DC signal formed by rectification is also 24V.

When the upper tube output unit 41 and the lower tube output unit 42 receive the high voltage DC signal formed by rectification, they are adjusted by a voltage regulator composed of a signal controller and a plurality of resistors to obtain the required total voltage and positive and negative voltages. The voltage adjustment is specifically described below:

The upper tube output unit 41 includes a first signal controller U2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5, and the first signal controller U2 includes an input end and an output end;

The input end of the first signal controller U2 is connected to the cathode of the first diode D1 and the third diode D3, and is used to receive the first high-voltage DC signal rectified by the first rectifying unit 31. The output end of the first signal controller U2 is connected to one end of the third resistor R3 and the first positive voltage output end VOUT1+.

The other end of the third resistor R3 is connected to one end of the fourth resistor R4 , the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5 , and the other end of the fifth resistor R5 is connected to the first negative voltage output terminal VOUT1 −.

Specifically, the positive DC signal and the negative DC signal rectified by the first rectifying unit 31 can be adjusted by changing the resistance values of the resistors R3, R4, and R5, and the total output voltage can be adjusted by the ratio of (R3+R4) to R5, specifically using the following formula:

Among them, V1 ₊ is the positive voltage output to the silicon carbide MOS upper tube, _V1- is the negative voltage output to the silicon carbide MOS lower tube, _V1 + _-V1- is the total voltage output to the silicon carbide MOS tube, when the total voltage reaches the driving voltage requirement of the silicon carbide MOS tube, the silicon carbide MOS tube will be turned on, _VREF is the reference voltage, the reference voltage is the voltage value of the DC signal rectified by the first rectifying unit 31, in the embodiment of the present application, the reference voltage is 24V.

The positive and negative voltages are adjusted by the ratio of R3 to (R4+R5), using the following formula:

in, It is the ratio of positive and negative voltages. The positive and negative voltages are adjusted while adjusting the total voltage. This is because the driving voltage threshold of the silicon carbide MOS tube is low and it is not easy to shut down at 0V. Therefore, negative voltage shutdown is usually adopted. Different types of silicon carbide MOS tubes have different negative voltage power supply requirements for negative voltage shutdown. Therefore, when adapting to different types of silicon carbide MOS, the output power supply negative voltage should also be adjusted accordingly.

The lower tube output unit 42 includes a second signal controller U3, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8, and the second signal controller U3 includes an input terminal and an output terminal;

The input end of the second signal controller U3 is connected to the cathodes of the fifth diode D5 and the sixth diode D6, and is used to receive the second high-voltage DC signal rectified by the second rectifying unit 32, and the output end of the second signal controller is connected to one end of the sixth resistor R6 and the second positive voltage output end VOUT2+;

The other end of the sixth resistor R6 is connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is connected to the second negative voltage output terminal VOUT2-.

Specifically, the method of adjusting the total voltage and positive and negative voltages of V ₂₊ and V ₂₋ is the same as that of the upper tube output unit 41 described above. The total voltage and positive and negative voltages output to the silicon carbide MOS lower tube can be adjusted by adjusting the resistance values of R6, R7 and R8.

More specifically, a ground signal can be constructed through a first-stage operational amplifier to prevent the output voltage from being unstable due to the direct output to the ground affecting the feedback of the DC signal. The following is a specific description of the voltage stabilization application of the operational amplifier:

The upper tube output unit 41 further includes a first operational amplifier U4, and the lower tube output unit 42 further includes a second operational amplifier U5;

The positive phase input terminal of the first operational amplifier U4 is connected to the connection point of the third resistor R3 and the fourth resistor R4, the negative phase input terminal of the first operational amplifier U4 is connected to the output terminal of the first operational amplifier U4, and the output terminal of the first operational amplifier U4 is grounded;

The positive phase input terminal of the second operational amplifier U5 is connected to the connection point of the sixth resistor R6 and the seventh resistor R7, the negative phase input terminal of the second operational amplifier U5 is connected to the output terminal of the second operational amplifier U5, and the output terminal of the second operational amplifier U5 is grounded.

Specifically, the negative phase input terminal of the first operational amplifier U4 is connected to the output terminal of the first operational amplifier U4, and the negative phase input terminal of the second operational amplifier U5 is connected to the output terminal of the second operational amplifier U5, respectively forming feedback circuits to ensure the stability of the signal output, using the output terminal as a reference voltage to maintain signal stability and avoid affecting the driving voltage value output to the silicon carbide MOS tube.

Furthermore, when it is necessary to replace the silicon carbide MOS with another driving voltage requirement, there is no need to change the layout or BOM of the PCB board. The voltage regulation signal is directly sent through the microcontroller to adapt the output drive power supply of the replaced silicon carbide MOS tube. The voltage regulation process is specifically described below:

The first voltage regulating unit 51 includes a first transistor Q1, a first photocoupler U6 and a ninth resistor R9; the first photocoupler U6 includes a first photodiode and a first phototransistor;

The base of the first transistor Q1 is connected to the single chip microcomputer for receiving the voltage regulation signal, the collector is connected to the cathode of the first photodiode, and the emitter is grounded;

The anode of the first photodiode is connected to an external level signal source, the collector of the first phototransistor is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is connected to the connection point of the fourth resistor R4 and the fifth resistor R5, and the emitter of the first phototransistor is connected to the first negative voltage output terminal VOUT1- and the other end of the fifth resistor R5;

The second voltage regulating unit 52 includes a second transistor Q2, a second photocoupler U7 and a tenth resistor R10; the second photocoupler U7 includes a second photodiode and a second phototransistor;

The base of the second transistor Q2 is connected to the single chip microcomputer for receiving the voltage regulation signal, the collector is connected to the cathode of the second photodiode, and the emitter is grounded;

The positive electrode of the second photodiode is connected to an external level signal source, the collector of the second phototransistor is connected to one end of the tenth resistor R10, the other end of the tenth resistor R10 is connected to the connection between the seventh resistor R7 and the eighth resistor R8, and the emitter of the second phototransistor is connected to the second negative voltage output terminal VOUT2- and the other end of the eighth resistor R8.

Specifically, the first voltage regulating unit 51 and the second voltage regulating unit 52 have the same principle. The first voltage regulating unit 51 is used as an example for explanation. When the single chip sends a voltage regulating signal to trigger the base of the first transistor Q1, the external DC signal source passes through the first photodiode and the first transistor Q1 to the ground, and the base of the first phototransistor thus senses the light signal to turn on the body diode. After the body diode of the first phototransistor is turned on, the control end of the first signal controller U2 in the first output unit 41 is turned on through the circuit of the resistor R9, the first phototransistor, and the first negative voltage output terminal VOUT1-, which is equivalent to connecting the resistor R9 in parallel at both ends of the resistor R5.

More specifically, after the resistor R5 and the resistor R9 are connected in parallel through the voltage regulation signal sent by the single chip microcomputer, the total voltage and the positive and negative voltages output to the upper tube can be adjusted at the same time. Regarding the regulation of the total voltage, the following formula is used:

Regarding the regulation of positive and negative voltages, the following formula is used:

Among them, R5//R9 is the resistance value of the resistor R5 and the resistor R9 in parallel, and the total voltage and positive and negative voltages output to the lower tube of the silicon carbide MOS tube are similarly replaced by the resistors R6, R7, R8 and R10 of the corresponding lower tube output unit 42 and the second voltage regulating unit 52, and the total voltage and positive and negative voltage values output to the lower tube after adjustment can be obtained by substituting them into the above formula.

The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. A compatible driving circuit for a silicon carbide MOS tube, characterized by comprising a square wave generating module, an isolated boosting module, a rectifying module, a voltage regulating output module and an isolated voltage regulating module; The square wave generating module is used to obtain the PWM signal sent by the external single-chip microcomputer and convert the PWM signal into a power square wave signal, and includes an input end and an output end. The input end of the square wave generating module is connected to the single-chip microcomputer, and the output end of the square wave generating module is used to output the converted power square wave signal. The isolation boost module is used to boost the power square wave signal into a high-voltage square wave signal, and the rectifier module is used to rectify the high-voltage square wave signal into a high-voltage DC signal, and the rectifier module includes a first rectifier unit and a second rectifier unit; The first rectifier unit and the second rectifier unit each include an input end and an output end; The isolated boost module comprises an input end and two output ends, the input end of the isolated boost module is connected to the output end of the square wave generating module, the first output end of the isolated boost module is connected to the input end of the first rectifier unit, and the second output end of the isolated boost module is connected to the input end of the second rectifier unit; The voltage regulating output module is used to adjust the high-voltage DC signal to a first driving voltage, and output the first driving voltage to the first silicon carbide MOS tube, wherein the first silicon carbide MOS tube includes a first MOS upper tube and a first MOS lower tube; The voltage regulating output module comprises an upper tube output unit and a lower tube output unit, and each of the upper tube output unit and the lower tube output unit comprises an input end, an output end and a voltage regulating end; The input end of the upper tube output unit is connected to the output end of the first rectifier unit, and is used to receive the high-voltage DC signal output by the first rectifier unit. The output end of the upper tube output unit is used to adjust the high-voltage DC signal to a DC signal suitable for the first MOS upper tube and output it to the upper tube. The input end of the lower tube output unit is connected to the output end of the second rectifier unit, and is used to receive the high-voltage DC signal output by the second rectifier unit. The output end of the lower tube output unit is used to adjust the high-voltage DC signal to a DC signal suitable for the first MOS lower tube and output it to the lower tube. The isolation voltage regulation module is used to obtain the voltage regulation signal sent by the single-chip computer, and adjust the first driving voltage to a second driving voltage according to the voltage regulation signal, and output the second driving voltage to a second silicon carbide MOS tube through the voltage regulation output module, wherein the second silicon carbide MOS tube includes a second MOS upper tube and a second MOS lower tube; The isolated voltage regulating module comprises a first voltage regulating unit and a second voltage regulating unit, wherein the first voltage regulating unit and the second voltage regulating unit each comprise an input end and an output end; The first voltage regulating unit is used to adjust the applicable DC signal of the first MOS upper tube to the applicable DC signal of the second MOS upper tube, the input end of the first voltage regulating unit is used to obtain the voltage regulating signal, and the output end of the first voltage regulating unit is connected to the voltage regulating end of the upper tube output unit; The second voltage regulating unit is used to adjust the applicable DC signal of the first MOS lower tube to the applicable DC signal of the second MOS lower tube, the input end of the second voltage regulating unit is used to obtain the voltage regulating signal, and the output end of the second voltage regulating unit is connected to the voltage regulating end of the lower tube output unit. 2. The compatible driving circuit of the silicon carbide MOS tube according to claim 1, characterized in that: the square wave generating module comprises a first resistor, a second resistor and a power square wave generator; The power square wave generator comprises a first square wave receiving end, a second square wave receiving end, a first power square wave output end and a second power square wave output end; One end of the first resistor is connected to the single chip microcomputer, and the other end is connected to the first square wave receiving end, and the first power square wave output end is connected to the input end of the isolation boost transformer; One end of the second resistor is connected to the single chip microcomputer, and the other end is connected to the second square wave receiving end. The second power square wave output end is connected to the input end of the isolation boost module. 3. The compatible driving circuit of the silicon carbide MOS tube according to claim 2, characterized in that: the square wave generating module further includes a first capacitor and a second capacitor; One end of the first capacitor is connected to the connection between the first resistor and the first square wave receiving end, and the other end is grounded; One end of the second capacitor is connected to the connection point between the second resistor and the second square wave receiving end, and the other end is grounded. 4. The compatible driving circuit of the silicon carbide MOS tube according to claim 2, characterized in that: the isolation boost module comprises a transformer, and the transformer comprises a primary winding, a first secondary winding and a second secondary winding; One end of the primary winding is connected to the first power square wave output end, and the other end is connected to the second power square wave output end; One end of the first secondary winding is connected to the output end of the first rectifier unit, and the other end is connected to the input end of the first rectifier unit; One end of the second secondary winding is connected to the output end of the second rectifier unit, and the other end is connected to the input end of the second rectifier unit. 5. The compatible driving circuit of the silicon carbide MOS tube according to claim 4 is characterized in that: the isolation boost module also includes a third capacitor; the third capacitor is connected in series between the first power square wave output end and one end of the primary winding. 6. The compatible driving circuit of the silicon carbide MOS tube according to claim 4, characterized in that: the first rectifying unit comprises a first diode, a second diode, a third diode and a fourth diode, and the second rectifying unit comprises a fifth diode, a sixth diode, a seventh diode and an eighth diode; The anode of the first diode is connected to one end of the first secondary winding and the cathode of the second diode, the cathode of the first diode is connected to the input end of the upper tube output unit, and the anode of the second diode is connected to the first negative voltage output end; An anode of the third diode is connected to the other end of the first secondary winding and a cathode of the fourth diode, and the cathode of the fourth diode is connected to the first negative voltage output terminal; The anode of the fifth diode is connected to one end of the second secondary winding and the cathode of the sixth diode, the cathode of the fifth diode is connected to the input end of the lower tube output unit, and the anode of the sixth diode is connected to the second negative voltage output end; An anode of the seventh diode is connected to the other end of the second secondary winding and a cathode of the eighth diode, and the cathode of the eighth diode is connected to the second negative voltage output end. 7. The compatible driving circuit of the silicon carbide MOS tube according to claim 6, characterized in that: the upper tube output unit comprises a first signal controller, a third resistor, a fourth resistor and a fifth resistor, and the first signal controller comprises an input end and an output end; The input end of the first signal controller is connected to the cathodes of the first diode and the third diode, and is used to receive the first high-voltage DC signal rectified by the first rectifying unit, and the output end of the first signal controller is connected to one end of the third resistor and the first positive voltage output end; The other end of the third resistor is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the first negative voltage output end; The lower tube output unit includes a second signal controller, a sixth resistor, a seventh resistor and an eighth resistor, and the second signal controller includes an input end and an output end; The input end of the second signal controller is connected to the cathodes of the fifth diode and the sixth diode, and is used to receive the second high-voltage DC signal rectified by the second rectifying unit, and the output end of the second signal controller is connected to one end of the sixth resistor and the second positive voltage output end; The other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to one end of the eighth resistor, and the other end of the eighth resistor is connected to the second negative voltage output terminal. 8. The compatible driving circuit of the silicon carbide MOS tube according to claim 7, characterized in that: the upper tube output unit further comprises a first operational amplifier, and the lower tube output unit further comprises a second operational amplifier; The positive phase input terminal of the first operational amplifier is connected to the connection point of the third resistor and the fourth resistor, the negative phase input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the output terminal of the first operational amplifier is grounded; The positive phase input terminal of the second operational amplifier is connected to the connection point of the sixth resistor and the seventh resistor, the negative phase input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier, and the output terminal of the second operational amplifier is grounded. 9. The compatible driving circuit of the silicon carbide MOS tube according to claim 7, characterized in that: the first voltage regulating unit comprises a first triode, a first photocoupler and a ninth resistor; the first photocoupler comprises a first photodiode and a first phototriode; The base of the first transistor is connected to the single chip microcomputer for receiving the voltage regulation signal, the collector is connected to the cathode of the first photodiode, and the emitter is grounded; The anode of the first photodiode is connected to an external level signal source, the collector of the first phototransistor is connected to one end of the ninth resistor, the other end of the ninth resistor is connected to the connection point of the fourth resistor and the fifth resistor, and the emitter of the first phototransistor is connected to the first negative voltage output end and the other end of the fifth resistor; The second voltage regulating unit includes a second triode, a second photocoupler and a tenth resistor; the second photocoupler includes a second photodiode and a second phototriode; The base of the second transistor is connected to the single chip microcomputer for receiving the voltage regulation signal, the collector is connected to the cathode of the second photodiode, and the emitter is grounded; The positive electrode of the second photodiode is connected to an external level signal source, the collector of the second phototransistor is connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the connection between the seventh resistor and the eighth resistor, and the emitter of the second phototransistor is connected to the second negative voltage output end and the other end of the eighth resistor. 10. A device, characterized by comprising a circuit structure of a compatible driving circuit of a silicon carbide MOS tube as claimed in any one of claims 1 to 9.