Drive circuit and power supply device

Abstract

The invention discloses a driving circuit and a power supply device. The driving circuit comprises a driver, an isolation power supply and at least one group of switching tubes, each group of switch tubes comprises a first switch tube and a second switch tube; a first output end of the driver is connected with a control end of the first switch tube, a second output end of the driver is connected with a control end of the second switch tube, a first end of the first switch tube is connected with a first power supply end, a second end of the second switch tube is connected with a second power supply end, and a second end of the first switch tube is connected with a first end of the second switch tube. The first control end of the driver is connected with the positive output end of the isolated power supply, and the input end of the isolated power supply is connected with the power supply input end; the output voltage of the isolation power supply is greater than or equal to the threshold voltage of the first switch tube, and the driver is used for driving the first switch tube and the second switch tube in a time-sharing manner. The driving capability and reliability of the driving circuit can be improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of power electronics technology, and in particular to a drive circuit and a power supply device. Background Art

[0002] Figure 1 A schematic diagram of a driving circuit provided in the related art. Figure 1 As shown, the driving circuit includes a high-end switch tube M1 and a low-end switch tube M2, the first electrode of the high-end switch tube M1 is connected to the power supply end Vpower, the second electrode of the high-end switch tube M1 is connected to the first electrode of the low-end switch tube M2, and serves as the output end VB of the driving circuit, connected to the load Rload of the driving circuit, and is used to drive the load Rload. The second electrode of the low-end switch tube M2 is grounded GND. During the operation of the driving circuit, the high-end switch tube M1 and the low-end switch tube M2 are turned on in time-sharing, and the voltage output by the driving circuit is controlled by adjusting the turn-on time of the high-end switch tube M1 and the low-end switch tube M2. Specifically, when the high-end switch tube M1 is turned off and the low-end switch tube M2 is turned on, the potential of the output end VB of the driving circuit is approximately equal to the potential of the ground end GND. In the next stage, it is necessary to control the high-end switch tube M1 to be turned on and the low-end switch tube M2 to be turned off, so that the power provided by the power supply end Vpower supplies power to the load Rload through the high-end switch tube M1. At this time, the bootstrap drive circuit can be used to make the potential of the control terminal of the high-end switch tube M1 greater than the sum of the threshold voltage Vth of the high-end switch tube M1 and the potential of the output terminal VB of the drive circuit, thereby realizing the conduction control of the high-end switch tube M1. In the related art, the charging time of the bootstrap drive circuit is limited by the duty cycle of the control signal of the high-end switch tube M1, which is prone to insufficient bootstrap drive force, resulting in unreliable conduction control of the high-end switch tube M1. Summary of the invention

[0003] The present invention provides a driving circuit and a power supply device to improve the driving capability of the driving circuit and the driving reliability of the driving circuit.

[0004] In a first aspect, an embodiment of the present invention provides a driving circuit, including a driver, an isolated power supply, and at least one group of switch tubes;

[0005] Each group of the switching tubes includes a first switching tube and a second switching tube; a first output terminal of the driver is connected to a control terminal of the first switching tube, a second output terminal of the driver is connected to a control terminal of the second switching tube, a first end of the first switching tube is connected to a first power supply terminal, a second end of the second switching tube is connected to a second power supply terminal, a second end of the first switching tube is connected to a first end of the second switching tube and is connected to a second control terminal of the driver and a negative output terminal of the isolated power supply, a first control terminal of the driver is connected to a positive output terminal of the isolated power supply, and an input terminal of the isolated power supply is connected to a power supply input terminal; an output voltage of the isolated power supply is greater than or equal to a threshold voltage of the first switching tube, and the driver is configured to drive the first switching tube and the second switching tube in a time-sharing manner.

[0006] Optionally, the driving circuit further includes a bootstrap capacitor, and the positive output terminal of the isolated power supply is connected to the second control terminal of the driver through the bootstrap capacitor.

[0007] Optionally, the driving circuit further includes a unidirectional conduction tube; an anode of the unidirectional conduction tube is connected to the positive output terminal of the isolated power supply, and a cathode of the unidirectional conduction tube is connected to the bootstrap capacitor.

[0008] Optionally, a power supply terminal of the driver is multiplexed as a power supply input terminal of the isolated power supply.

[0009] Optionally, the driving circuit further includes a first resistor and a second resistor;

[0010] The first resistor is connected between the first output terminal of the driver and the control terminal of the first switching tube, and the second resistor is connected between the second output terminal of the driver and the control terminal of the second switching tube.

[0011] Optionally, the driving circuit further includes a first diode and a second diode;

[0012] An anode of the first diode is connected to a second end of the first switching tube, a cathode of the first diode is connected to a first end of the first switching tube, an anode of the second diode is connected to a second end of the second switching tube, and a cathode of the second diode is connected to a first end of the second switching tube.

[0013] Optionally, the isolated power supply includes at least one of a discrete isolated power supply and an integrated isolated power supply.

[0014] Optionally, the discrete isolated power supply includes a transformer, a switching unit, a third diode, and a first capacitor;

[0015] The first end of the primary side of the transformer is connected to the power input terminal. The switching unit is connected between the second end of the primary side of the transformer and the ground terminal. The anode of the third diode is connected to the first end of the secondary side of the transformer. The cathode of the third diode is connected to the first pole of the first capacitor and serves as the positive output terminal of the discrete isolated power supply. The second pole of the first capacitor is connected to the second end of the secondary side of the transformer and serves as the negative output terminal of the discrete isolated power supply. The first end of the primary side of the transformer and the second end of the secondary side of the transformer are the same-named terminals.

[0016] Optionally, the switching unit includes a third switching transistor and a fourth diode;

[0017] The first end of the third switching transistor and the anode of the fourth diode are grounded. The second end of the third switching transistor and the cathode of the fourth diode are connected to the second end of the primary side of the transformer. The control end of the third switching transistor is used to input a control signal.

[0018] In a second aspect, an embodiment of the present invention further provides a power supply device, including the driving circuit described in the first aspect.

[0019] In the technical solution of the embodiment of the present invention, by connecting the negative output terminal of the isolated power supply to the second control terminal of the driver, the potentials of the two are made the same. At the same time, the output voltage of the isolated power supply is greater than the threshold voltage of the first switching transistor. When the second switching transistor is turned off, the isolated power supply can control the potential difference between the control terminal and the second terminal of the first switching transistor to be the output voltage of the isolated power supply, that is, it can control the potential difference between the control terminal and the second terminal of the first switching transistor to be greater than or equal to the threshold voltage, so as to ensure that the first switching transistor is turned on and meet the driving requirements of the first switching transistor. Moreover, the driving circuit provided by the embodiment of the present invention has a simple structure and wider applicability. At the same time, the driving force for driving the first switching transistor to turn on by the driving circuit is not limited by the on-time of the first switching transistor, which can not only improve the stability and reliability of the driving circuit, but also be applicable to high-frequency application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a driving circuit provided for the related art;

[0021] Figure 2 A schematic structural diagram of a driving circuit provided by an embodiment of the present invention;

[0022] Figure 3 A schematic structural diagram of another driving circuit provided by an embodiment of the present invention;

[0023] Figure 4 A schematic structural diagram of another driving circuit provided by an embodiment of the present invention;

[0024] Figure 5 Schematic diagram of another driving circuit provided by an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of a discrete isolated power supply provided by an embodiment of the present invention. Detailed implementation manners

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0027] Figure 2 Schematic diagram of a driving circuit provided by an embodiment of the present invention. As Figure 2 shown, the driving circuit includes a driver 110, an isolated power supply 120, and at least one group of switching tubes 130; each group of switching tubes includes a first switching tube T1 and a second switching tube T2; the first output terminal Ho of the driver 110 is connected to the control terminal of the first switching tube T1, the second output terminal Lo of the driver 110 is connected to the control terminal of the second switching tube T2, the first end of the first switching tube T1 is connected to the first power supply terminal V1, the second end of the second switching tube T2 is connected to the second power supply terminal V2, the second end of the first switching tube T1 is connected to the first end of the second switching tube T2, and is connected to the second control terminal Vb of the driver 110 and the negative output terminal V- of the isolated power supply 120, the first control terminal Vs of the driver 110 is connected to the positive output terminal V+ of the isolated power supply 120, and the input terminal of the isolated power supply 120 is connected to the power input terminal VDD; the output voltage of the isolated power supply 120 is greater than the threshold voltage of the first switching tube T1, and the driver 110 is used to drive the first switching tube T1 and the second switching tube T2 in a time-sharing manner.

[0028] Specifically, the first power supply terminal V1 can provide a first power supply with a positive voltage, and the second power supply terminal V2 can be a ground terminal. At this time, the first switching transistor T1 is a high-side switching transistor, and the second switching transistor T2 is a low-side switching transistor. The second terminal of the first switching transistor T1 and the first terminal of the second switching transistor T2 are connected and used as the output terminal of the drive circuit to supply power to the load. The driver 110 can control the first switching transistor T1 and the second switching transistor T2 to conduct in a time-sharing manner, and by controlling the conduction time of the first switching transistor T1 and the second switching transistor T2, the voltage output by the drive circuit can be controlled, so as to supply power to different loads. Exemplarily, the first switching transistor T1 and the second switching transistor T2 can be metal-oxide-semiconductor field-effect transistors (MOSFETs) of the same type. At this time, the control signal levels output by the first output terminal Ho and the second output terminal Lo of the driver 110 are opposite. For example, when the types of the first switching transistor T1 and the second switching transistor T2 are both N-type transistors, when the first output terminal Ho outputs a high level and the second output terminal Lo outputs a low level, the first switching transistor T1 conducts and the second switching transistor T2 turns off.

[0029] The isolated power supply 120 has an isolation function, enabling electrical isolation between the input power supply and the output power supply of the isolated power supply 120. The negative output terminal V- of the isolated power supply 120 is connected to the second control terminal Vb of the driver 110 and the first terminal of the second switching transistor T2. When the second switching transistor T2 is turned on and the first switching transistor T1 is turned off, the potential of the second control terminal Vb is equivalent to the potential of the second potential terminal V2. In the next stage, when the second switching transistor T2 is turned off and the first switching transistor T1 is turned on, the driver 110 can control the first control terminal Vs to be connected to the first output terminal Ho, and the potential provided by the positive output terminal V+ of the isolated power supply 120 can be output to the control terminal of the first switching transistor T1 through the first output terminal Ho. At the same time, the potential of the second control terminal Vb is in a floating state. The negative output terminal V- of the isolated power supply 120 is connected to the second control terminal Vb, making the potential of the negative output terminal V- of the isolated power supply 120 the potential of the second control terminal Vb, that is, the potential of the second terminal of the first switching transistor T1. At this time, the isolated power supply 120 is constructed with the potential of the second control terminal Vb as the reference ground plane. Thus, throughout the switching cycle of the drive circuit, it can be ensured that the potential difference between the control terminal and the second terminal of the first switching transistor T1 is the output voltage of the isolated power supply 120, effectively eliminating the floating change of the potential of the second control terminal Vb during operation. When the output voltage of the isolated power supply 120 is greater than the threshold voltage of the first switching transistor T1, the potential difference between the control terminal and the second terminal of the first switching transistor T1 can be made greater than or equal to the threshold voltage of the first switching transistor T1, thereby enabling the first switching transistor T1 to be turned on and meeting the driving requirements of the first switching transistor T1. Moreover, the above drive circuit has a simple structure and wider applicability. At the same time, the driving force for driving the first switching transistor T1 to conduct is not limited by the conduction time of the first switching transistor T1, that is, not limited by the duty cycle of the effective level output by the first output terminal Ho of the driver 110, improving the stability and reliability of the drive circuit and being applicable to high-frequency application scenarios. Among them, the effective level output by the first output terminal Ho is the level for controlling the first switching transistor T1 to conduct. When the first switching transistor T1 is an N-type switching transistor, the effective level output by the first output terminal Ho is a high level. When the first switching transistor T1 is a P-type switching transistor, the effective level output by the first output terminal Ho is a low level.

[0030] It should be noted that in some embodiments, the output voltage of the isolated power supply 120 is less than the withstand voltage of the first output terminal Ho port of the driver 110, avoiding damage to the driver 110 caused by too high an output voltage of the isolated power supply 120.

[0031] In the technical solution of this embodiment, by connecting the negative output terminal of the isolated power supply to the second control terminal of the driver, the potentials of the two are made the same. At the same time, the output voltage of the isolated power supply is greater than the threshold voltage of the first switching transistor. When the second switching transistor is turned off, the isolated power supply can control the potential difference between the control terminal and the second terminal of the first switching transistor to be the output voltage of the isolated power supply, that is, it can control the potential difference between the control terminal and the second terminal of the first switching transistor to be greater than or equal to the threshold voltage, so as to ensure that the first switching transistor is turned on and meet the driving requirements of the first switching transistor. Moreover, the driving circuit provided by the embodiment of the present invention has a simple structure and wider applicability. At the same time, the driving force for driving the first switching transistor to turn on by the driving circuit is not limited by the on-time of the first switching transistor, which can not only improve the stability and reliability of the driving circuit, but also be applicable to high-frequency application scenarios.

[0032] Figure 3 FIG. is a schematic structural diagram of another driving circuit provided by an embodiment of the present invention. As Figure 3 shown, the driving circuit further includes a bootstrap capacitor Cd. The positive output terminal V+ of the isolated power supply 120 is connected to the second control terminal Vb of the driver 110 through the bootstrap capacitor Cd.

[0033] Specifically, the voltage across the bootstrap capacitor Cd cannot change suddenly. When the second switching transistor T2 is turned on and the first switching transistor T1 is turned off, the potential of the second control terminal Vb is equivalent to the potential of the second potential terminal V2, for example, the ground terminal potential, 0V. At this time, the potential of the negative output terminal V- of the isolated power supply 120 is equivalent to the potential of the second potential terminal V2, and the output voltage of the isolated power supply 120 is greater than or equal to the threshold voltage of the first switching transistor T1, then the potential of the positive output terminal V+ of the isolated power supply 120 is greater than the potential of the second control terminal Vb, and the output voltage of the isolated power supply 120 can charge the bootstrap capacitor Cd. In the next stage, when the second switching transistor T2 is turned off and the first switching transistor T1 is turned on, the potential of the second control terminal Vb rises, that is, the potential of one end of the bootstrap capacitor Cd rises. At this time, the bootstrap effect of the bootstrap capacitor Cd makes the potential difference between the other end of the bootstrap capacitor Cd and one end of the bootstrap capacitor Cd still the output voltage of the isolated power supply 120, so that the potential difference between the control terminal and the second terminal of the first switching transistor T1 can be greater than the threshold voltage of the first switching transistor T1, meeting the driving requirements of the first switching transistor T1. At the same time, it can be ensured that the voltage across the bootstrap capacitor Cd is constantly the output voltage of the isolated power supply 120 throughout the switching cycle of the driving circuit, without being restricted by the charging and discharging time of the bootstrap capacitor Cd, improving the stability and reliability of the driving circuit and being applicable to high-frequency application scenarios.

[0034] Figure 4 FIG. is a schematic structural diagram of another driving circuit provided by an embodiment of the present invention. As Figure 4As shown, the drive circuit further includes a unidirectional conduction tube Db; the anode of the unidirectional conduction tube Db is connected to the positive output terminal V+ of the isolated power supply 120, and the cathode of the unidirectional conduction tube Db is connected to the bootstrap capacitor Cd.

[0035] Specifically, the unidirectional conduction tube Db has a unidirectional conduction function. When the isolated power supply 120 drives the first switching tube T1 and / or charges the bootstrap capacitor Cd, the output voltage of the isolated power supply 120 can be output to the bootstrap capacitor Cd and the first control terminal Vs of the driver 110 through the unidirectional conduction tube Db. At the same time, it can prevent the bootstrap capacitor Cd from discharging in the direction of the isolated power supply 120, and can prevent the first power supply provided by the first power supply terminal V1 from being back-fed to the isolated power supply 120 through the coupling action of the bootstrap capacitor Cd, thereby reducing the coupling process between the isolated power supply 120 and other structures.

[0036] Figure 5 It is a schematic structural diagram of another drive circuit provided by an embodiment of the present invention. As Figure 5 shown, the power supply terminal VSS of the driver 110 is multiplexed as the power supply input terminal VDD of the isolated power supply 120.

[0037] Specifically, the power supply terminal VSS of the driver 110 is used to supply power to the driver 110. The input voltage and the output voltage of the isolated power supply 120 have no direct relationship, and the input voltage of the isolated power supply 120 can be any voltage value. At this time, the power supply input terminal VDD of the isolated power supply 120 can be multiplexed with the power supply terminal VSS of the driver 110, avoiding the need to separately set the power supply input terminal VDD of the isolated power supply 120, reducing the number of power supplies required for the drive circuit, and simplifying the structure of the drive circuit.

[0038] Continue to refer to Figures 2 to 5 , the drive circuit further includes a first resistor R1 and a second resistor R2; the first resistor R1 is connected between the first output terminal Ho of the driver 110 and the control terminal of the first switching tube T1, and the second resistor R2 is connected between the second output terminal Lo of the driver 110 and the control terminal of the second switching tube T2.

[0039] Specifically, the first resistor R1 is connected between the first output terminal Ho of the driver 110 and the control terminal of the first switching tube T1, and can limit the current of the control signal output by the first output terminal Ho, and is used to limit the current of the first switching tube T1 for protection. Similarly, the second resistor R2 is connected between the second output terminal Lo of the driver 110 and the control terminal of the second switching tube T2, and can limit the current of the control signal output by the second output terminal Lo, and is used to limit the current of the second switching tube T2 for protection.

[0040] Continue to refer to Figures 2 to 5, the drive circuit further includes a first diode D1 and a second diode D2; the anode of the first diode D1 is connected to the second end of the first switching tube T1, the cathode of the first diode D1 is connected to the first end of the first switching tube T1, the anode of the second diode D2 is connected to the second end of the second switching tube T2, and the cathode of the second diode D2 is connected to the first end of the second switching tube T2.

[0041] Specifically, the first diode D1 is reversely connected in parallel with the first switching tube T1 and can conduct freewheeling when the first switching tube T1 is turned off. The second diode D2 is reversely connected in parallel with the second switching tube T2 and can conduct freewheeling when the second switching tube T2 is turned off, so that continuous switching of the first switching tube T1 and the second switching tube T2 can be achieved.

[0042] In some embodiments, the isolated power supply includes at least one of a discrete isolated power supply and an integrated isolated power supply.

[0043] Specifically, the isolated power supply can be an isolated power supply in any form. Exemplarily, the isolated power supply can be a discrete isolated power supply built by a transformer-like device, such as a flyback switching power supply. The isolated power supply can also be an integrated isolated power supply composed of integrated devices. Different forms of isolated power supplies can provide a driving voltage for the first switching tube T1, and no limitation is made here.

[0044] Figure 6 FIG. is a schematic structural diagram of a discrete isolated power supply provided by an embodiment of the present invention. As Figure 6 shown, the discrete isolated power supply 120 includes a transformer 121, a switching unit 122, a third diode D3, and a first capacitor C1; the first end of the primary side of the transformer 121 is connected to the power input terminal VDD, the switching unit 122 is connected between the second end of the primary side of the transformer 121 and the ground terminal GND, the anode of the third diode D3 is connected to the first end of the secondary side of the transformer 121, the cathode of the third diode D3 is connected to the first pole of the first capacitor C1 and serves as the positive output terminal V+ of the discrete isolated power supply, the second pole of the first capacitor C1 is connected to the second end of the secondary side of the transformer 121 and serves as the negative output terminal V- of the discrete isolated power supply, and the first end of the primary side of the transformer 121 and the second end of the secondary side of the transformer 121 are the same-name terminals.

[0045] Specifically, when the switch unit 122 is turned on, the input voltage provided by the power input terminal VDD is loaded through the primary side winding of the transformer 121, and the current in the primary side winding increases, causing the primary side winding of the transformer 121 to store electrical energy. At this time, the potential of the first end of the primary side of the transformer 121 is greater than the potential of the second end of the primary side. The second end of the secondary side of the transformer 121 and the first end of the primary side of the transformer 121 are the same-name terminals, that is, the potential of the second end of the secondary side of the transformer 121 is greater than the potential of the first end of the secondary side of the transformer 121. The third diode D3 is in the cut-off state, and the voltage provided by the first capacitor C1 is the output voltage of the discrete isolated power supply 120. When the switch unit 122 is turned off, the voltage of the primary side winding of the transformer 121 reverses, causing the voltage direction of the secondary side winding of the transformer 121 to be opposite to that in the previous stage. The third diode D3 conducts, and the secondary side winding of the transformer 121 supplies power to the first capacitor C1 and the load. At this time, the voltage provided by the transformer 121 is the output voltage of the discrete isolated power supply 120.

[0046] Continue to refer to Figure 6 , the switch unit 122 includes a third switching transistor T3 and a fourth diode D4; the first end of the third switching transistor T3 and the anode of the fourth diode D4 are grounded to GND, the second end of the third switching transistor T3 and the cathode of the fourth diode D4 are connected to the second end of the primary side of the transformer 121, and the control end of the third switching transistor T3 is used to input a control signal.

[0047] Specifically, Figure 6 exemplarily shows that the switch unit 122 includes a switching transistor. At this time, the third switching transistor T3 can control the conduction state between the second end of the primary side of the transformer 121 and the ground terminal GND. When the third switching transistor T3 is turned on, the circuit between the second end of the primary side of the transformer 121 and the ground terminal GND is connected, enabling the input voltage provided by the power input terminal VDD to be transmitted to the primary side of the transformer 121. When the third switching transistor T3 is turned off, the circuit between the second end of the primary side of the transformer 121 and the ground terminal GND is disconnected, and the input voltage provided by the power input terminal VDD cannot be transmitted to the primary side of the transformer 121. The primary side winding of the transformer 121 discharges, causing the voltage of the primary side of the transformer 121 to reverse, and a reverse electromotive force can be induced on the secondary side of the transformer 121, causing the third diode D3 to conduct. In addition, the fourth diode D4 is reversely connected in parallel with the third switching transistor T3 for freewheeling when the third switching transistor T3 is turned off.

[0048] The embodiment of the present invention also provides a power supply device. The power supply device includes the driving circuit provided in any embodiment of the present invention. Since the power supply device includes the driving circuit provided in any embodiment of the present invention, it has the same beneficial effects as the driving circuit provided in any embodiment of the present invention, which will not be elaborated here.

[0049] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A driving circuit, characterized in that: It includes a driver, an isolated power supply and at least one set of switch tubes; Each group of switch tubes includes a first switch tube and a second switch tube; the first output end of the driver is connected to the control end of the first switch tube, the second output end of the driver is connected to the control end of the second switch tube, the first end of the first switch tube is connected to the first power supply end, the second end of the second switch tube is connected to the second power supply end, the second end of the first switch tube is connected to the first end of the second switch tube, and is connected to the second control end of the driver and the negative output end of the isolated power supply, the first control end of the driver is connected to the positive output end of the isolated power supply, and the input end of the isolated power supply is connected to the power supply input end; the output voltage of the isolated power supply is greater than or equal to the threshold voltage of the first switch tube, and the driver is used to drive the first switch tube and the second switch tube in time-sharing.

2. The driving circuit according to claim 1, characterized in that: The driving circuit further includes a bootstrap capacitor, and the positive output terminal of the isolated power supply is connected to the second control terminal of the driver through the bootstrap capacitor.

3. The driving circuit according to claim 2, characterized in that: The driving circuit also includes a unidirectional conduction tube; an anode of the unidirectional conduction tube is connected to the positive output end of the isolation power supply, and a cathode of the unidirectional conduction tube is connected to the bootstrap capacitor.

4. The driving circuit according to claim 1, characterized in that: The power supply terminal of the driver is reused as the power supply input terminal of the isolated power supply.

5. The driving circuit according to claim 1, characterized in that: The driving circuit also includes a first resistor and a second resistor; The first resistor is connected between the first output terminal of the driver and the control terminal of the first switch tube, and the second resistor is connected between the second output terminal of the driver and the control terminal of the second switch tube.

6. The driving circuit according to claim 1, characterized in that: The driving circuit also includes a first diode and a second diode; The anode of the first diode is connected to the second end of the first switch tube, the cathode of the first diode is connected to the first end of the first switch tube, the anode of the second diode is connected to the second end of the second switch tube, and the cathode of the second diode is connected to the first end of the second switch tube.

7. The driving circuit according to any one of claims 1 to 6, characterized in that: The isolated power supply includes at least one of a discrete isolated power supply and an integrated isolated power supply.

8. The driving circuit according to claim 7, characterized in that: The discrete isolated power supply includes a transformer, a switch unit, a third diode and a first capacitor; The first end of the primary side of the transformer is connected to the power input end, the switch unit is connected between the second end of the primary side of the transformer and the ground end, the anode of the third diode is connected to the first end of the secondary side of the transformer, the cathode of the third diode is connected to the first pole of the first capacitor and serves as the positive output end of the discrete isolated power supply, the second pole of the first capacitor is connected to the second end of the secondary side of the transformer and serves as the negative output end of the discrete isolated power supply, and the first end of the primary side of the transformer and the second end of the secondary side of the transformer are the same-named terminals.

9. The driving circuit according to claim 8, characterized in that: The switch unit includes a third switch tube and a fourth diode; The first end of the third switch tube and the anode of the fourth diode are grounded, the second end of the third switch tube and the cathode of the fourth diode are connected to the second end of the primary side of the transformer, and the control end of the third switch tube is used to input a control signal.

10. A power supply device, characterized in that: The driving circuit comprises the driving circuit according to any one of claims 1 to 9.

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