Power device driving circuit

Abstract

The utility model discloses a power device driving circuit. The power device driving circuit comprises a driving module, a power supply module, a voltage stabilizing module, a power supply adjusting module, a conduction module and a comparison module. The driving module is connected with a control electrode of the power device; the output end of the power supply module is connected with the first power supply end of the driving module; the voltage stabilizing module is connected between the first power supply end of the driving module and the second power supply end of the driving module; a first input end of the comparison module is connected with a first pole of the power device through the conduction module, a second input end of the comparison module is connected with a reference voltage, and an output end of the comparison module is connected with the power supply adjusting module; the comparison module is configured to receive the feedback voltage when the conduction module is conducted and output a turn-off signal to the power supply adjusting module; the power supply adjusting module is connected with the output end and the adjusting end of the power supply module. The drive circuit provided by the utility model can reduce the conduction loss of the power device while controlling the power device to be quickly turned off.

Description

Technical Field

[0001] The utility model relates to the technical field of drive circuits, in particular to a power device drive circuit. Background Art

[0002] Power devices include power transistors, and power transistors include power field effect transistors, insulated gate bipolar transistors, gallium nitride transistors, etc. The control signal output by the controller is converted into a drive voltage by the drive circuit and transmitted to the power device to control the conduction and turn-off of the power device, and further control the electrical parameters of the power output by the power device, such as controlling the power of the power output by the power device. Gallium nitride transistors are widely used due to their high electron mobility characteristics.

[0003] The controller outputs a pulse width modulation (PWM) signal to the drive circuit. When the PWM signal is at a high level, the drive circuit provides a high-level drive voltage for the gallium nitride transistor, causing the gallium nitride transistor to conduct. When the PWM signal is at a low level, the drive circuit provides a low-level drive voltage for the gallium nitride transistor, causing the gallium nitride transistor to turn off.

[0004] In order to increase the speed and accelerate the turn-off of the gallium nitride transistor, generally, the low-level drive voltage is set to be relatively small, such as a negative voltage with a relatively large absolute value. Therefore, when the drive circuit transmits a negative voltage with a relatively large absolute value to the gallium nitride transistor, the gallium nitride transistor can be controlled to turn off quickly. The reverse conduction voltage of the gallium nitride transistor is V SD1 -V g_off where V SD1 is the reverse conduction voltage of the gallium nitride transistor when the drive voltage is 0, and V g_off is the drive turn-off voltage. The drive turn-off voltage V g_off is a negative voltage with a relatively large absolute value, resulting in a relatively large voltage drop when the gallium nitride transistor conducts in the reverse direction, thereby increasing the conduction loss of the gallium nitride transistor and reducing the efficiency of the gallium nitride transistor. Summary of the Utility Model

[0005] The utility model provides a power device drive circuit to solve the problem of large conduction loss while achieving fast turn-off of the power device.

[0006] The utility model provides a power device drive circuit, which includes: a drive module, a power supply module, a voltage stabilization module, a power supply adjustment module, a conduction module, and a comparison module;

[0007] The drive module is connected to the control pole of the power device, and the drive module is configured to transmit a drive voltage to the control pole of the power device;

[0008] The output terminal of the power supply module is connected to the first power supply terminal of the drive module, and the voltage stabilization module is connected between the first power supply terminal and the second power supply terminal of the drive module;

[0009] The first input terminal of the comparison module is connected to the first pole of the power device through the conduction module, the second input terminal of the comparison module is connected to a reference voltage, and the output terminal of the comparison module is connected to the power supply adjustment module; the conduction module is configured to conduct when the power device conducts reversely; the comparison module is configured to receive a feedback voltage when the conduction module conducts and output a turn-off signal to the power supply adjustment module; wherein, the feedback voltage is less than the reference voltage;

[0010] The power supply adjustment module is respectively connected to the output terminal and the adjustment terminal of the power supply module, and the power supply adjustment module is configured to adjust the voltage of the output terminal of the power supply module according to the turn-off signal.

[0011] Optionally, the power supply adjustment module includes a switching transistor, a first resistor, a second resistor, and a third resistor;

[0012] The first resistor is connected between the output terminal and the adjustment terminal of the power supply module;

[0013] The first end of the second resistor is electrically connected to the adjustment terminal, and the second end of the second resistor is connected to a second power supply;

[0014] The control pole of the switching transistor is electrically connected to the output terminal of the comparison module, the first pole of the switching transistor is connected to the adjustment terminal through the third resistor, and the second pole of the switching transistor is connected to the second power supply.

[0015] Optionally, the power device drive circuit further includes a voltage dividing module;

[0016] The first end of the voltage dividing module is connected to a first power supply, the second end of the voltage dividing module is connected to the first input terminal of the comparison module, and the third end of the voltage dividing module is connected to a second power supply; the voltage dividing module is configured to transmit a divided voltage to the first input terminal of the comparison module when the conduction module is turned off; wherein, the divided voltage is greater than the reference voltage, the comparison module is configured to output a turn-on signal to the power supply adjustment module when receiving the divided voltage, and the power supply adjustment module is configured to adjust the output voltage of the power supply module to an initial voltage according to the turn-on signal.

[0017] Optionally, the voltage dividing module includes a fourth resistor and a fifth resistor;

[0018] The first end of the fourth resistor is connected to the first power supply, and the second end of the fourth resistor is electrically connected to the first input terminal of the comparison module;

[0019] The first end of the fifth resistor is electrically connected to the second end of the fourth resistor, and the second end of the fifth resistor is connected to the second power supply.

[0020] Optionally, the voltage stabilizing module includes a voltage stabilizing diode and a sixth resistor;

[0021] The first pole of the voltage stabilizing diode is electrically connected to the first power supply terminal of the driving module, and the second pole of the voltage stabilizing diode is connected to the second power supply through the sixth resistor;

[0022] The second power supply terminal of the driving module is connected to the second power supply;

[0023] The second pole of the power device is electrically connected to the second pole of the voltage stabilizing diode.

[0024] Optionally, the conduction module includes a diode;

[0025] The first pole of the diode is electrically connected to the first input terminal of the comparison module, the second pole of the diode is electrically connected to the first pole of the power device, and the second pole of the power device is grounded.

[0026] Optionally, the comparison module includes a comparator;

[0027] The first input terminal of the comparator is connected to the first pole of the power device through the conduction module, the second input terminal of the comparator is connected to a reference voltage, and the output terminal of the comparator is connected to the power supply regulation module;

[0028] The power supply regulation module further includes a seventh resistor;

[0029] The first end of the seventh resistor is electrically connected to the control pole of the switching transistor, and the second end of the seventh resistor is connected to the second power supply.

[0030] Optionally, the driving module includes a driver, a first driving resistor, and a second driving resistor;

[0031] The first power supply terminal of the driver is electrically connected to the output terminal of the power supply module, the second power supply terminal of the driver is connected to the second power supply, and the input terminal of the driver is connected to a control signal;

[0032] The first driving resistor is connected between the first output terminal of the driver and the control pole of the power device;

[0033] The second driving resistor is connected between the second output terminal of the driver and the control electrode of the power device; the driver is configured to transmit a driving voltage of a first level to the power device through the first driving resistor or transmit a driving voltage of a second level to the power device through the second driving resistor according to the control signal.

[0034] Optionally, the power device driving circuit further includes a controller and a digital isolator;

[0035] The digital isolator is connected between the controller and the input terminal of the driver, and the controller is configured to transmit a control signal to the driver through the digital isolator.

[0036] Optionally, the power device driving circuit further includes a first capacitor and a second capacitor;

[0037] A first pole of the first capacitor is electrically connected to a first pole of the voltage stabilizing diode, a second pole of the first capacitor is electrically connected to a second pole of the voltage stabilizing diode, a first pole of the second capacitor is electrically connected to the second pole of the voltage stabilizing diode, and a second pole of the second capacitor is electrically connected to a second power supply terminal of the driving module.

[0038] In the technical solution of the embodiment of the present invention, the power device driving circuit includes a driving module, a power supply module, a voltage stabilizing module, a power supply adjusting module, a conducting module, and a comparing module; when the driving module outputs a negative voltage with a relatively large absolute value to the power device, the power device can be quickly turned off, and the power device can conduct reversely. When the power device conducts reversely, the conducting module conducts, and the comparing module can receive a feedback voltage related to the voltage of the first pole of the power device. If the feedback voltage is less than the reference voltage, the comparing module will output a turn-off signal to the power supply adjusting module. The power supply adjusting module adjusts the voltage of the output terminal of the power supply module, thereby adjusting the voltage of the first power supply terminal of the driving module. For example, the voltage of the first power supply terminal of the driving module is reduced, and the voltage drop of the voltage stabilizing module remains unchanged, that is, the voltage difference between the two ends of the voltage stabilizing module remains unchanged, so that the voltage of the second power supply terminal of the driving module increases, thereby increasing the negative voltage output by the driving module, so that the absolute value of the driving voltage of the low level output by the driving module is smaller, and the voltage drop when the power device conducts reversely is reduced, thereby reducing the conduction loss of the power device. In this way, while controlling the power device to be quickly turned off, the conduction loss of the power device can be reduced.

[0039] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0041] Figure 1 is a schematic structural diagram of a power device drive circuit provided by an embodiment of the present utility model;

[0042] Figure 2 is a schematic structural diagram of another power device drive circuit provided by an embodiment of the present utility model;

[0043] Figure 3 is a schematic structural diagram of another power device drive circuit provided by an embodiment of the present utility model;

[0044] Figure 4 is a schematic structural diagram of another power device drive circuit provided by an embodiment of the present utility model;

[0045] Figure 5 A drive timing diagram of a power device provided by an embodiment of the present utility model. Detailed implementation manners

[0046] In order to enable those skilled in the art to better understand the solution of the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present utility model and the above accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0048] In view of the problem that the power device has a large conduction loss while achieving fast turn-off, this embodiment provides a power device drive circuit. The power device includes a power transistor, and the power transistor includes a power field effect transistor, an insulated gate bipolar transistor, a gallium nitride transistor, etc.

[0049] Figure 1 is a schematic structural diagram of a power device drive circuit provided by an embodiment of the present invention. Refer to Figure 1 , the power device drive circuit includes: a drive module 110, a power supply module 120, a voltage stabilization module 130, a power supply adjustment module 140, a conduction module 150, and a comparison module 160;

[0050] The drive module 110 is connected to the control electrode of the power device 210, and the drive module 110 is configured to transmit a drive voltage to the control electrode of the power device 210;

[0051] The output terminal Vout of the power supply module 120 is connected to the first power supply terminal VDD of the drive module 110, and the voltage stabilization module 130 is connected between the first power supply terminal VDD and the second power supply terminal of the drive module 110;

[0052] The first input terminal of the comparison module 160 is connected to the first electrode of the power device 210 through the conduction module 150, the second input terminal of the comparison module 160 is connected to the reference voltage Vref, and the output terminal of the comparison module 160 is connected to the power supply adjustment module 140; the conduction module 150 is configured to conduct when the power device 210 conducts in the reverse direction; the comparison module 160 is configured to receive a feedback voltage when the conduction module 150 conducts, and output a turn-off signal to the power supply adjustment module 140; wherein, the feedback voltage is less than the reference voltage Vref;

[0053] The power supply adjustment module 140 is respectively connected to the output terminal Vout and the adjustment terminal ADJ of the power supply module 120, and the power supply adjustment module 140 is configured to adjust the voltage of the output terminal Vout of the power supply module 120 according to the turn-off signal.

[0054] Among them, the driving module 110 may include a driver or a driving circuit, which is not limited in this embodiment. The driving module 110 may output a driving voltage to the control electrode of the power device 210 according to a control signal, and the control signal is, for example, a pulse width modulation signal. When the pulse width modulation signal is at the first level, the driving module 110 outputs a driving voltage at the first level to the control electrode of the power device 210, and the power device 210 conducts forward. When the pulse width modulation signal is at the second level, the driving module 110 outputs a driving voltage at the second level to the control electrode of the power device 210, so that the power device 210 is turned off, and the power device 210 can conduct reversely. Among them, for example, the first level is a high level and the second level is a low level; or the first level is a low level and the second level is a high level, which is not limited in this embodiment.

[0055] When the power device 210 conducts forward, the potential of the first electrode of the power device 210 is greater than the potential of the second electrode of the power device 210. When the power device 210 conducts reversely, the potential of the first electrode of the power device 210 is less than the potential of the second electrode of the power device 210. For example, the second electrode of the power device 210 is connected to the power ground PGND, that is, the potential of the second electrode of the power device 210 is zero. Among them, the control electrode of the power device 210 is the gate. For example, the first electrode of the power device 210 is the source electrode and the second electrode of the power device 210 is the drain electrode; or the first electrode of the power device 210 is the drain electrode and the second electrode of the power device 210 is the source electrode. The first electrode of the power device 210 may be connected to a load or other circuits, which is not limited in this embodiment.

[0056] The power supply module 120 includes an adjustable power supply, that is, the output voltage of the power supply module 120 is adjustable. For example, the power supply module 120 includes an adjustable low dropout regulator (LDO). The power supply module 120 supplies power to the driving module 110, and the voltage stabilizing module 130 can stabilize the potential between the first power supply terminal VDD of the driving module 110 and the second power supply terminal of the driving module 110. The conduction module 150 is, for example, a unidirectional conduction module. The conduction module 150 can conduct or turn off according to the voltage of the first electrode of the power device 210, that is, the conduction module 150 conducts or turns off according to the state of the power device 210. When the power device 210 conducts forward, the potential of the first electrode of the power device 210 is greater than zero, and the conduction module 150 is turned off; when the power device 210 conducts reversely, the potential of the first electrode of the power device 210 is less than zero, and the conduction module 150 conducts. When the conduction module 150 conducts, the comparison module 160 can receive a feedback voltage related to the voltage of the first electrode of the power device 210.

[0057] The comparison module 160 can compare the reference voltage Vref at the first input terminal and the second input terminal of the comparison module 160, and output a turn-off signal or a turn-on signal according to the comparison result. Among them, the reference voltage Vref is greater than 0. The power supply adjustment module 140 can maintain the voltage at the output terminal Vout of the power supply module 120 as the initial voltage according to the turn-on signal output by the comparison module 160. The power supply adjustment module 140 can also adjust the voltage at the output terminal Vout of the power supply module 120 according to the turn-off signal output by the comparison module 160.

[0058] Specifically, for example, the first level is a high level and the second level is a low level. When the driving module 110 outputs a driving voltage of a high level, the power device 210 conducts forward, the conduction module 150 does not conduct, the comparison module 160 cannot receive the feedback voltage related to the voltage of the first pole of the power device 210, and the comparison module 160 does not output a turn-off signal, that is, the comparison module 160 outputs a turn-on signal. The power supply adjustment module 140 maintains the voltage at the output terminal Vout of the power supply module 120 as the initial voltage according to the turn-on signal output by the comparison module 160, so that the power device 210 conducts forward normally. When the driving module 110 outputs a driving voltage of a low level, the driving voltage of the low level is a negative voltage with a relatively large absolute value, then the power device 210 can be controlled to turn off quickly, and the power device 210 can conduct reversely. When the power device 210 conducts reversely, the conduction module 150 conducts, and the comparison module 160 can receive the feedback voltage. The feedback voltage is less than the reference voltage Vref, then the comparison module 160 outputs a turn-off signal to the power supply adjustment module 140. The power supply adjustment module 140 adjusts the voltage at the output terminal Vout of the power supply module 120 according to the turn-off signal output by the comparison module 160. For example, the voltage at the output terminal Vout of the power supply module 120 is reduced, then the voltage at the first power supply terminal VDD of the driving module 110 is reduced, and the voltage difference across the voltage stabilizing module 130 remains unchanged, so that the voltage at the second power supply terminal of the driving module 110 increases, for example, increases to 0V, thereby increasing the driving voltage output by the driving module 110, that is, reducing the absolute value of the driving voltage output by the driving module 110. The absolute value of the voltage at the control pole of the power device 210 is reduced, then the voltage difference between the first pole and the second pole of the power device 210 is reduced, that is, the voltage drop when the power device 210 conducts reversely is reduced, and further the conduction loss of the power device 210 is reduced. In this way, while controlling the power device 210 to turn off quickly, the conduction loss of the power device 210 can be reduced.

[0059] In the technical solution of this embodiment, the power device drive circuit includes a drive module, a power supply module, a voltage stabilization module, a power supply adjustment module, a conduction module, and a comparison module; when the drive module outputs a negative voltage with a large absolute value to the power device, the power device can be quickly turned off, and the power device can conduct reversely. When the power device conducts reversely, the conduction module conducts, and the comparison module can receive a feedback voltage related to the voltage of the first pole of the power device. If the feedback voltage is less than the reference voltage, the comparison module will output a turn-off signal to the power supply adjustment module. The power supply adjustment module adjusts the voltage at the output end of the power supply module, thereby adjusting the voltage at the first power supply terminal of the drive module. For example, the voltage at the first power supply terminal of the drive module is reduced, while the voltage difference across the voltage stabilization module remains unchanged, so that the voltage at the second power supply terminal of the drive module increases, thereby increasing the negative voltage output by the drive module, making the absolute value of the low-level drive voltage output by the drive module smaller, reducing the voltage drop when the power device conducts reversely, and further reducing the conduction loss of the power device. In this way, while controlling the power device to quickly turn off, the conduction loss of the power device can be reduced.

[0060] Based on the above technical solution, Figure 2 is a schematic structural diagram of another power device drive circuit provided by an embodiment of the present invention. Optionally, referring to Figure 2 , the power supply adjustment module 140 includes a switching transistor Q1, a first resistor R1, a second resistor R2, and a third resistor R3;

[0061] The first resistor R1 is connected between the output terminal Vout and the adjustment terminal ADJ of the power supply module 120;

[0062] The first end of the second resistor R2 is electrically connected to the adjustment terminal ADJ, and the second end of the second resistor R2 is connected to the second power supply VSS;

[0063] The control electrode of the switching transistor Q1 is electrically connected to the output terminal of the comparison module 160. The first pole of the switching transistor Q1 is connected to the adjustment terminal ADJ through the third resistor R3, and the second pole of the switching transistor Q1 is connected to the second power supply VSS.

[0064] Specifically, when the comparison module 160 outputs a conduction signal, the switching transistor Q1 conducts, then the third resistor R3 is connected to the circuit. After the third resistor R3 is connected in parallel with the second resistor R2 and then connected in series with the first resistor R1. The voltage at the adjustment terminal ADJ of the power supply module 120 is V r , then then the voltage output at the output terminal Vout of the power supply module 120 is where V r is the reference voltage inside the power supply module 120. R1 is the resistance value of the first resistor R1, R2 is the resistance value of the second resistor R2, and R3 is the resistance value of the third resistor R3.

[0065] When the comparison module 160 outputs a turn-off signal, the switching transistor Q1 turns off, then the third resistor R3 is not connected to the circuit, and the first resistor R1 and the second resistor R2 are connected in series. Then the voltage output by the output terminal Vout of the power supply module 120 is less than In this way, the voltage of the output terminal Vout of the power supply module 120 can be reduced, and the voltage difference across the voltage regulation module 130 remains unchanged. Then the voltage of the second power supply terminal of the driving module 110 can be increased, for example, increased to zero, so that the absolute value of the voltage at the control electrode of the power device 210 is smaller, thereby reducing the voltage drop loss when the power device 210 conducts reversely.

[0066] Based on the above technical solution, Figure 3 which is a schematic structural diagram of another power device driving circuit provided by an embodiment of the present invention. Optionally, referring to Figure 3 , the power device driving circuit further includes a voltage dividing module 170;

[0067] The first end of the voltage dividing module 170 is connected to the first power supply VCC, the second end of the voltage dividing module 170 is connected to the first input end of the comparison module 160, and the third end of the voltage dividing module 170 is connected to the second power supply VSS; the voltage dividing module 170 is configured to transmit a divided voltage to the first input end of the comparison module 160 when the conduction module 150 is turned off; wherein, the divided voltage is greater than the reference voltage, and the comparison module 160 is configured to output a conduction signal to the power supply adjustment module 140 when receiving the divided voltage, and the power supply adjustment module 140 is configured to adjust the output voltage of the power supply module 120 to the initial voltage according to the conduction signal.

[0068] Specifically, when the driving module 110 outputs a high-level driving voltage, the power device 210 conducts forward, the conduction module 150 does not conduct, the comparison module 160 cannot receive the feedback voltage related to the voltage of the first pole of the power device 210, and the voltage dividing module 170 converts the voltage of the first power supply VCC into a divided voltage and transmits it to the first input end of the comparison module 160. Since the divided voltage is greater than the reference voltage, the comparison module 160 will output a conduction signal to the power supply adjustment module 140. Then the switching transistor Q1 in the power supply adjustment module 140 conducts, connecting the third resistor R3 into the circuit, making the output voltage of the power supply module 120 larger, which is the initial voltage, so that the absolute value of the driving voltage output by the driving module 110 is larger, maintaining the conduction of the power device 210.

[0069] Among them, for example, the conduction signal output by the comparison module 160 is a high-level signal, and the turn-off signal output by the comparison module 160 is a low-level signal; or, the conduction signal output by the comparison module 160 is a low-level signal, and the turn-off signal output by the comparison module 160 is a high-level signal. This embodiment does not make a limitation. For example, the first input terminal of the comparison module 160 is the non-inverting input terminal, and the second input terminal of the comparison module 160 is the inverting input terminal.

[0070] Based on the above technical solution, Figure 4 is a schematic structural diagram of another power device driving circuit provided by an embodiment of the present invention. Optionally, referring to Figure 4 , the voltage dividing module 170 includes a fourth resistor R4 and a fifth resistor R5;

[0071] The first end of the fourth resistor R4 is connected to the first power supply VCC, and the second end of the fourth resistor R4 is electrically connected to the first input terminal of the comparison module 160;

[0072] The first end of the fifth resistor R5 is electrically connected to the second end of the fourth resistor R4, and the second end of the fifth resistor R5 is connected to the second power supply VSS.

[0073] Specifically, the voltage provided by the first power supply VCC is Vcc, the resistance value of the fourth resistor R4 is R4, and the resistance value of the fifth resistor R5 is R5. Then, the divided voltage transmitted by the voltage dividing module 170 to the first input terminal of the comparison module 160 is When the divided voltage is greater than the reference voltage, the comparison module 160 will output a conduction signal to the power supply adjustment module 140. Then, the switching transistor Q1 in the power supply adjustment module 140 conducts, connecting the third resistor R3 into the circuit, so that the output voltage of the power supply module 120 is relatively large and is the initial voltage.

[0074] Moreover, when the power device 210 conducts forward, the voltage of the first pole of the power device 210 is relatively large, and the difference between the divided voltage and the voltage of the first pole of the power device 210 does not meet the conduction condition of the conduction module 150, so that the conduction module 150 is turned off, and the first input terminal of the comparison module 160 is connected to the divided voltage. When the power device 210 conducts reversely, the voltage of the first pole of the power device 210 is relatively small, so that the difference between the divided voltage and the voltage of the first pole of the power device 210 meets the conduction condition of the conduction module 150, so that the conduction module 150 is turned off, and the first input terminal of the comparison module 160 is connected to the feedback voltage.

[0075] Optionally, referring to Figure 4 , the voltage stabilizing module 130 includes a voltage stabilizing diode D1 and a sixth resistor R6;

[0076] The first pole of the voltage stabilizing diode D1 is electrically connected to the first power supply terminal VDD of the driving module 110, and the second pole of the voltage stabilizing diode D1 is connected to the second power supply VSS through the sixth resistor R6;

[0077] The second power supply terminal of the driving module 110 is connected to the second power supply VSS;

[0078] The second pole of the power device 210 is electrically connected to the second pole of the voltage stabilizing diode D1.

[0079] Specifically, by setting the voltage stabilizing diode D1, the voltage between the first power supply terminal and the second power supply terminal of the driving module 110 can be stabilized, ensuring the stability of the power supply of the driving module 110.

[0080] For example, the initial voltage output by the output terminal Vout of the power supply module 120 is 9.2V. For example, the voltage stabilizing value Vz of the voltage stabilizing diode D1 is 6.2V. Then the voltage stabilizing diode D1 can limit the voltage of the first terminal VDD of the driving module 110 to 6.2V, and the driving voltage of the high level output by the driving module 110 is 6.2V. Then the voltage between the second power supply terminals of the driving module 110 is Vz - Vout = 6.2 - 9.2 = -3V, so that the driving voltage of the low level output by the driving module 110 is -3V, which can control the rapid turn-off of the power device 210. When the power device 210 conducts reversely, the conduction module 150 conducts, enabling the comparison module 160 to output a turn-off signal to the switching transistor Q1, and the switching transistor Q1 turns off, thereby reducing the voltage of the output terminal Vout of the power supply module 120. For example, when the voltage of the output terminal Vout of the power supply module 120 is reduced to 6.2V, the voltage between the second power supply terminals of the driving module 110 is Vz - Vout = 6.2 - 6.2 = 0, so that the driving voltage of the low level output by the driving module 110 is 0V, thereby reducing the voltage drop loss of the reverse conduction of the power device 210.

[0081] Optionally, referring to Figure 4 , the conduction module 150 includes a diode D2;

[0082] The first pole of the diode D2 is electrically connected to the first input terminal of the comparison module 160, the second pole of the diode D2 is electrically connected to the first pole of the power device 210, and the second pole of the power device 210 is grounded.

[0083] Wherein, the second pole of the power device 210 is connected to the power ground PGND.

[0084] Specifically, for example, the first pole of diode D2 is the cathode, and the second pole of diode D2 is the anode. When the power device 210 conducts forward, the voltage of the first pole of the power device 210 is relatively large and does not meet the conduction voltage of the power device 210. When the power device 210 conducts reversely, the voltage of the first pole of the power device 210 is relatively small. When the power device 210 is a gallium nitride transistor, the reverse conduction voltage drop of the gallium nitride transistor is less than -1.2V, that is, the voltage of the first pole of the power device 210 is relatively small, causing the diode D2 to conduct.

[0085] When the diode D2 conducts, the feedback voltage transmitted to the first input terminal of the comparison module 160 is the voltage difference between the first pole and the second pole of the power device 210 minus the voltage drop of the diode D2. Since the voltage drop of the diode D2 is less than the voltage drop of the power device 210 (the voltage difference between the first pole and the second pole of the power device 210), the feedback voltage is less than 0, while the reference voltage Vref is greater than 0. The feedback voltage is less than the reference voltage Vref, causing the comparison module 160 to output a turn-off signal to the switching transistor Q1, and the switching transistor Q1 turns off, thereby reducing the voltage of the output terminal Vout of the power supply module 120.

[0086] Optionally, referring to Figure 4 , the comparison module 160 includes a comparator U1;

[0087] The first input terminal of the comparator U1 is connected to the first pole of the power device 210 through the conduction module 150. The second input terminal of the comparator U1 is connected to the reference voltage Vref. The output terminal of the comparator U1 is connected to the power supply regulation module 140;

[0088] The power supply regulation module 140 further includes a seventh resistor R7;

[0089] The first end of the seventh resistor R7 is electrically connected to the control pole of the switching transistor Q1, and the second end of the seventh resistor R7 is connected to the second power supply VSS.

[0090] Specifically, for example, the first input terminal of the comparator U1 is the non-inverting input terminal, and the second input terminal of the comparator U1 is the inverting input terminal. When the power device 210 conducts in the forward direction, the diode D1 is turned off, and the divided voltage is input to the first input terminal of the comparator U1. The divided voltage is greater than the reference voltage Vref, causing the comparator U1 to output a conduction signal to the switching transistor Q1. The switching transistor Q1 conducts, and the third resistor R3 is connected to the circuit, making the voltage output at the output terminal Vout of the power supply module 120 larger. When the power device 210 conducts in the reverse direction, the diode D1 conducts, and the feedback voltage is input to the first input terminal of the comparator U1. The feedback voltage is less than the reference voltage Vref, causing the comparator U1 to output a turn-off signal to the switching transistor Q1. The switching transistor Q1 turns off, and the third resistor R3 is not connected to the circuit, reducing the voltage output at the output terminal Vout of the power supply module 120 and decreasing the voltage at the first power supply terminal of the driving module 110. The voltage difference across the zener diode D1 remains unchanged, increasing the voltage at the second power supply terminal of the driving module 110, increasing the low-level driving voltage output by the driving module 110, that is, reducing the absolute value of the low-level driving voltage, thereby reducing the voltage drop loss of the power device 210.

[0091] Optionally, referring to Figure 4 , the driving module 110 includes a driver U2, a first driving resistor Ron, and a second driving resistor Roff;

[0092] The first power supply terminal VDD of the driver U2 is electrically connected to the output terminal Vout of the power supply module 120. The second power supply terminal of the driver U2 is connected to the second power supply VSS, and the input terminal of the driver U2 receives the control signal P1;

[0093] The first driving resistor Ron is connected between the first output terminal of the driver U2 and the control electrode of the power device 210;

[0094] The second driving resistor Roff is connected between the second output terminal of the driver U2 and the control electrode of the power device 210. The driver U2 is configured to transmit a driving voltage of a first level to the power device 210 through the first driving resistor Ron or transmit a driving voltage of a second level to the power device 210 through the second driving resistor Roff according to the control signal P1.

[0095] Specifically, the first level is a high level, and the second level is a low level. The control signal P1 is a pulse width modulation signal. When the control signal P1 is at a high level, the driver U2 outputs a high-level driving voltage to the control electrode of the power device 210, causing the power device 210 to conduct in the forward direction. When the control signal P1 is at a low level, the driver U2 outputs a low-level driving voltage to the control electrode of the power device 210, causing the power device 210 to turn off, and the power device 210 can conduct in the reverse direction.

[0096] Optionally, referring to Figure 4 , the power device driving circuit further includes a controller U3 and a digital isolator U4;

[0097] The digital isolator U4 is connected between the input end of the controller U3 and the driver U2, and the controller U3 is configured to transmit a control signal to the driver U2 through the digital isolator U4.

[0098] Specifically, the controller U3 may include a digital signal processor (DSP), or may include a field programmable gate array device (FPGA), or may include other devices such as a single-chip microcomputer, which is not limited in this embodiment. The controller U1 may output a control signal P1, and the control signal P1 is transmitted to the driver U2 through the digital isolator U4, so that the driver U2 outputs a driving voltage of low level or high level according to the control signal P1, thereby controlling the conduction or turn-off of the power device 210. By setting the digital isolator U4, it is avoided that the voltage between the driver U2 and the power device 210 is too large, which affects the controller U3, and the effect of protecting the controller U3 is achieved.

[0099] Optionally, referring to Figure 4 , the power device driving circuit further includes a first capacitor C1 and a second capacitor C2;

[0100] The first pole of the first capacitor C1 is electrically connected to the first pole of the voltage stabilizing diode D1, the second pole of the first capacitor C1 is electrically connected to the second pole of the voltage stabilizing diode D1, the first pole of the second capacitor C2 is electrically connected to the second pole of the voltage stabilizing diode D1, and the second pole of the second capacitor C2 is electrically connected to the second power supply terminal of the driving module 110.

[0101] Specifically, by setting the first capacitor C1 and the second capacitor C2, filtering can be performed, so that the voltage between the first power supply terminal and the second power supply terminal of the driving module 110 is more stable, which is beneficial to improving the stability and reliability of the operation of the power device driving circuit.

[0102] Exemplarily, Figure 5 A driving timing diagram of a power device provided by an embodiment of the present invention, referring to Figure 5 , at the moment t0, the power device 210 conducts forward, the diode D1 turns off, and the divided voltage is input to the first input terminal of the comparator U1, so that the voltage V at the first input terminal of the comparator U1 +Greater than the reference voltage Vref, such that the voltage V1 at the output terminal of the comparator U1 is a high-level conduction signal, the switching transistor Q1 conducts, and the third resistor R3 is connected into the circuit, making the voltage output at the output terminal Vout of the power supply module 120 larger. Then, the voltage at the second power supply terminal of the driving module 110 is a negative voltage with a larger absolute value, such that the low-level driving voltage V2 output by the driving module 110 is a negative voltage with a larger absolute value.

[0103] At time t1, the power device 210 conducts in the reverse direction, the diode D1 conducts, and the feedback voltage is input to the first input terminal of the comparator U1, such that the voltage V at the first input terminal of the comparator U1 + Less than the reference voltage Vref, such that the voltage V1 at the output terminal of the comparator U1 is a low-level turn-off signal, the switching transistor Q1 turns off, the third resistor R3 is not connected into the circuit, the voltage output at the output terminal Vout of the power supply module 120 is reduced, and the voltage at the first power supply terminal of the driving module 110 is reduced. The voltage difference across the zener diode D1 remains unchanged, such that the voltage at the second power supply terminal of the driving module 110 increases, such that the low-level driving voltage V2 output by the driving module 110 increases, that is, the absolute value of the low-level driving voltage V2 decreases, thereby reducing the voltage drop loss of the power device 210.

[0104] At time t2, the power device 210 conducts in the forward direction, the voltage output at the output terminal Vout of the power supply module 120 returns to the initial voltage, the voltage at the second power supply terminal of the driving module 110 is a negative voltage with a larger absolute value, and the power device 210 conducts normally.

[0105] Thus, the power device driving circuit provided in this embodiment can provide a negative voltage with a larger absolute value for the power device, such that the power device turns off quickly, and then adjusts the driving voltage to a voltage with a smaller absolute value, such that the voltage drop loss of the power device is smaller.

[0106] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A power device driving circuit, characterized in that: include: Driving module, power module, voltage stabilizing module, power regulating module, conduction module and comparison module; The driving module is connected to the control electrode of the power device, and the driving module is configured to transmit a driving voltage to the control electrode of the power device; The output end of the power module is connected to the first power end of the driving module, and the voltage stabilizing module is connected between the first power end of the driving module and the second power end of the driving module; The first input end of the comparison module is connected to the first pole of the power device through the conduction module, the second input end of the comparison module is connected to the reference voltage, and the output end of the comparison module is connected to the power regulation module; the conduction module is configured to be turned on when the power device is reversely conducted; the comparison module is configured to receive a feedback voltage when the conduction module is turned on, and output a shutdown signal to the power regulation module; wherein the feedback voltage is less than the reference voltage; The power regulating module is connected to the output end and the regulating end of the power module respectively, and the power regulating module is configured to regulate the voltage of the output end of the power module according to the shutdown signal.

2. The power device driving circuit according to claim 1, characterized in that: The power regulation module includes a switch transistor, a first resistor, a second resistor and a third resistor; The first resistor is connected between the output end of the power module and the adjustment end; A first end of the second resistor is electrically connected to the adjustment end, and a second end of the second resistor is connected to a second power supply; The control electrode of the switch transistor is electrically connected to the output end of the comparison module, the first electrode of the switch transistor is connected to the adjustment end through the third resistor, and the second end of the switch transistor is connected to the second power supply.

3. The power device driving circuit according to claim 1, characterized in that: The power device driving circuit also includes a voltage dividing module; The first end of the voltage divider module is connected to the first power supply, the second end of the voltage divider module is connected to the first input end of the comparison module, and the third end of the voltage divider module is connected to the second power supply; the voltage divider module is configured to transmit the divided voltage to the first input end of the comparison module when the conduction module is turned off; wherein, the divided voltage is greater than the reference voltage, the comparison module is configured to output a conduction signal to the power supply regulating module when receiving the divided voltage, and the power supply regulating module is configured to adjust the output voltage of the power supply module to the initial voltage according to the conduction signal.

4. The power device driving circuit according to claim 3, characterized in that: The voltage dividing module includes a fourth resistor and a fifth resistor; A first end of the fourth resistor is connected to the first power supply, and a second end of the fourth resistor is electrically connected to the first input end of the comparison module; The first end of the fifth resistor is electrically connected to the second end of the fourth resistor, and the second end of the fifth resistor is connected to a second power supply.

5. The power device driving circuit according to claim 1, characterized in that: The voltage stabilizing module includes a voltage stabilizing diode and a sixth resistor; The first electrode of the voltage stabilizing diode is electrically connected to the first power supply terminal of the driving module, and the second electrode of the voltage stabilizing diode is connected to the second power supply through the sixth resistor; The second power supply terminal of the driving module is connected to the second power supply; The second electrode of the power device is electrically connected to the second electrode of the Zener diode.

6. The power device driving circuit according to claim 1, characterized in that: The conduction module includes a diode; A first electrode of the diode is electrically connected to a first input terminal of the comparison module, a second electrode of the diode is electrically connected to a first electrode of the power device, and a second electrode of the power device is grounded.

7. The power device driving circuit according to claim 2, characterized in that: The comparison module includes a comparator; The first input end of the comparator is connected to the first electrode of the power device through the conduction module, the second input end of the comparator is connected to the reference voltage, and the output end of the comparator is connected to the power supply regulation module; The power supply regulating module also includes a seventh resistor; A first end of the seventh resistor is electrically connected to the control electrode of the switch transistor, and a second end of the seventh resistor is connected to the second power supply.

8. The power device driving circuit according to claim 1, characterized in that: The driving module includes a driver, a first driving resistor and a second driving resistor; The first power supply terminal of the driver is electrically connected to the output terminal of the power supply module, the second power supply terminal of the driver is connected to the second power supply, and the input terminal of the driver is connected to the control signal; The first driving resistor is connected between the first output terminal of the driver and the control electrode of the power device; The second driving resistor is connected between the second output terminal of the driver and the control electrode of the power device; the driver is configured to transmit a first level of driving voltage to the power device through the first driving resistor, or transmit a second level of driving voltage to the power device through the second driving resistor according to the control signal.

9. The power device driving circuit according to claim 8, characterized in that: The power device driving circuit also includes a controller and a digital isolator; The digital isolator is connected between the controller and an input terminal of the driver, and the controller is configured to transmit a control signal to the driver through the digital isolator.

10. The power device driving circuit according to claim 5, characterized in that: The power device driving circuit also includes a first capacitor and a second capacitor; The first electrode of the first capacitor is electrically connected to the first electrode of the Zener diode, the second electrode of the first capacitor is electrically connected to the second electrode of the Zener diode, the first electrode of the second capacitor is electrically connected to the second electrode of the Zener diode, and the second electrode of the second capacitor is electrically connected to the second power supply terminal of the driving module.

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