A MOSFET-based isolated drive circuit system for ease of control

Abstract

This invention discloses a MOSFET-based isolated drive circuit system that is easy to control, comprising: an input voltage regulator circuit, a transformer drive circuit, a transformer secondary rectifier and filter circuit, a drive output, and a negative voltage bootstrap circuit; wherein, the input voltage regulator circuit includes: a linear voltage regulator element, a drive power supply, a feedback network, and a filter capacitor; the input terminal of the linear voltage regulator element is coupled to the drive power supply, the drive power supply input voltage is VIN, and the linear voltage regulator element is connected to ground through the coupled feedback network; the input voltage regulator circuit is used to provide a stable DC input to the transformer drive circuit. This invention separates the secondary winding of the transformer in the auxiliary power supply of traditional technology and places it in a discrete transformer, effectively reducing the insulation requirements of the auxiliary power supply transformer and making it easier to drive more MOSFETs. By driving with high-voltage MOSFETs, the problem of excessive auxiliary power supply windings is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of power supply drive circuit technology, specifically to a MOSFET-based isolated drive circuit system that is easy to control. Background Technology

[0002] MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) used in high-voltage, high-power power supplies require isolated driving. The current main solution is to use an auxiliary power supply to generate multiple mutually isolated voltages and pass the isolated voltages into isolation devices such as optocouplers to drive the MOSFETs, or to use a drive transformer to isolate the drive signal of the power device.

[0003] In commonly used high-voltage converter architectures, auxiliary power supplies typically require multiple isolated low-voltage windings as the power source for the power device drive circuits. These low-voltage windings occupy the transformer window space, affecting transformer performance design, and in higher voltage architectures, they can also create the risk of insulation failure.

[0004] Currently, multiple output windings in auxiliary power supplies result in excessively large transformer sizes, making coil winding difficult. The isolation voltage is too high, placing excessive demands on the transformer's insulation level. Furthermore, it is difficult for drive transformers to effectively match different MOSFETs.

[0005] Existing technologies can no longer meet people's current needs, and based on the current situation, there is an urgent need to improve existing technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a MOSFET-based isolated drive circuit system that is easy to control, so as to solve the problems mentioned in the background art.

[0007] This invention provides a MOSFET-based isolated drive circuit system that is easy to control, comprising: an input voltage regulator circuit, a transformer drive circuit, a transformer secondary rectifier and filter circuit, a drive output, and a negative voltage bootstrap circuit; wherein, The input voltage regulator circuit includes: a linear voltage regulator, a drive power supply, a feedback network, and a filter capacitor; The input terminal of the linear voltage regulator is coupled to the driving power supply, which has an input voltage VIN. The linear voltage regulator is connected to ground through a coupled feedback network. The feedback network consists of a first resistor and a second resistor, which are connected in series and in parallel with the linear voltage regulator. The input voltage regulator circuit is used to provide a stable DC input to the transformer drive circuit.

[0008] The transformer drive circuit includes: a PWM controller, a PWM driver, an RC charging and discharging circuit, a transformer, and a first capacitor; the output terminal of the linear voltage regulator is connected to the power supply terminals of the PWM controller and the PWM driver through a coupling filter capacitor; the PWM controller is grounded through a coupling RC charging and discharging circuit; the RC charging and discharging circuit includes: a third resistor, a second capacitor, and a third capacitor; wherein the third resistor is connected in parallel with the second and third capacitors, and the second and third capacitors are connected in parallel; the output terminal of the PWM controller is connected to the PWM driver, the PWM controller outputs a PWM control signal which is loaded onto the PWM driver, the output terminal of the PWM driver is connected to the transformer, and the primary coil of the transformer is connected to the PWM driver through the first capacitor.

[0009] The transformer drive circuit is used to generate an isolation power supply for the drive optocoupler OPT in the signal processing module; wherein, the control method of the transformer drive circuit includes the following specific steps: S101: Receives the PWM signal from the PWM controller through the PWM driver, amplifies the PWM signal, and drives the current to flow on the transformer, transferring energy to the secondary coil of the transformer. S102: The PWM driver outputs a high level, causing current to flow from the input terminal of the transformer through the primary coil and the first capacitor to ground, gradually increasing the voltage of the first capacitor, storing some energy, and raising the potential of the transformer coil output terminal; S103: When the interrupted PWM output is high, the PWM controller outputs a low level, which drives the PWM driver to output a low level. When the potential at the input terminal of the transformer is equal to GND and the potential at the output terminal is equal to the voltage across the first capacitor, the current in the primary coil of the transformer flows in reverse, transferring energy to the secondary coil of the transformer.

[0010] The transformer secondary rectifier and filter circuit includes: a first diode, a second diode, a first bootstrap capacitor, and an energy storage capacitor; wherein, the secondary coil of the transformer is coupled to the first bootstrap capacitor and then connected to the positive terminal of the first diode and the negative terminal of the second diode respectively, and an energy storage capacitor is provided between the negative terminal of the first diode and the positive terminal of the second diode; the negative terminal of the first diode and the positive terminal of the second diode serve as the positive output terminal and the negative output terminal of the transformer secondary rectifier and filter circuit respectively, and are connected to the drive output and the negative voltage bootstrap circuit; the transformer secondary rectifier and filter circuit rectifies and filters the transformer output signal and then transmits it to the drive output and the negative voltage bootstrap circuit.

[0011] The transformer secondary rectifier and filter circuit is used to rectify and filter the signal output from the transformer drive circuit; wherein, the specific steps of the control method for the transformer secondary rectifier and filter circuit include: S201: Set the upper end of the transformer to a high level and the lower end to a low level, so that the current direction of the transformer secondary coil is from bottom to top. The current passes through the first bootstrap capacitor, the first diode, and the energy storage capacitor and returns to the lower end of the transformer secondary coil. The voltage at the left end of the first bootstrap capacitor and the upper end of the energy storage capacitor will gradually increase, and the current will gradually decrease.

[0012] S202: Set the upper end of the transformer to low level and the lower end to high level, so that the current direction of the transformer secondary coil is from top to bottom. The current flows out of the transformer secondary coil, through the second diode, and the first bootstrap capacitor returns to the upper end of the transformer secondary coil. Due to the unidirectional conduction of the first diode, no current flows through the energy storage capacitor, and the voltage remains unchanged; while the voltage on the first bootstrap capacitor changes from left positive and right negative to left negative and right positive, raising the voltage at the right end of the bootstrap capacitor.

[0013] S203: Set the upper end of the transformer to high level and the lower end to low level again, so that the current direction on the secondary coil of the transformer is from bottom to top again. The voltage at the left end of the first diode is equal to the voltage at the upper end of the secondary coil of the transformer plus the voltage of the first bootstrap capacitor, thus charging the energy storage capacitor.

[0014] The drive output and negative voltage bootstrap circuit includes: input terminal IN+ and input terminal IN-, used to receive input signals; the input terminals IN+ and IN- serve as the input terminals of the drive output and negative voltage bootstrap circuit, respectively coupled to the positive output terminal and negative output terminal of the transformer secondary rectifier filter circuit.

[0015] The drive output and negative pressure bootstrap circuit further includes: a signal processing module and a first output terminal Vg and a second output terminal Vs; wherein, the signal processing module is connected between the input terminal and the output terminal.

[0016] The signal processing module includes: a fourth pull-down resistor, a driving optocoupler OPT, a fourth diode, a fifth diode, and a second bootstrap capacitor.

[0017] The pull-down fourth resistor is connected at one end to the IN+ pin and at the other end to the second output terminal Vs; the driving optocoupler OPT includes a first MOSFET and a second MOSFET, wherein the source of the first MOSFET is connected to the IN+ pin, the drain and gate of the first MOSFET are connected to the drain and gate of the second MOSFET respectively, and the source of the second MOSFET is connected to the second output terminal Vs through a third diode; the fourth diode and the fifth diode are connected in the same direction and are coupled to the output terminal of the driving optocoupler OPT between the fourth diode and the fifth diode; the second bootstrap capacitor is connected at one end to the input terminal IN- and at the other end to the second output terminal Vs.

[0018] The drive output and negative voltage bootstrap circuit is used to output positive and negative drive signals to the MOSFET in the drive optocoupler OPT; wherein, the specific steps of the control method for the drive output and negative voltage bootstrap circuit include: S301: Drive the optocoupler OPT to output a high level. The input voltage at the input terminal IN+ is connected to the first output terminal Vg through the first MOSFET inside the drive optocoupler OPT. The first output terminal Vg is connected to the gate of the second MOSFET. The current flows through the gate, source and pull-down fourth resistor of the second MOSFET, and then flows into the second output terminal Vs. It then flows back to the input terminal IN- through the second bootstrap capacitor.

[0019] S302: Drive the optocoupler OPT to output a low level. The first output terminal Vg is turned on through the second MOSFET inside the optocoupler OPT, and the gate capacitance Cgs of the second MOSFET is rapidly discharged through the third diode.

[0020] The present invention has the following beneficial effects: (1) The present invention separates the secondary winding of the transformer in the auxiliary power supply in the traditional technology and puts it into a discrete transformer, which effectively reduces the insulation requirements of the auxiliary power supply transformer and makes it easier to drive more MOSFETs. By driving with high voltage MOSFETs, the problem of too many auxiliary power supply windings is effectively solved.

[0021] (2) The present invention can be easily adapted to various subsequent circuits, and the input voltage regulator circuit can be easily modified according to the different required voltages to adapt to different MOSFET parameters.

[0022] (3) Compared with the drive circuit using pulse transformer, the present invention has a wider range of applications and stronger versatility, and can be easily adapted to different types of MOSFETs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the circuit structure of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the present invention without creative effort are within the scope of protection of the present invention.

[0025] refer to Figure 1 The present invention provides a MOSFET-based isolated drive circuit system that is easy to control, comprising: an input voltage regulator circuit, a transformer drive circuit, a transformer secondary rectifier and filter circuit, a drive output and a negative voltage bootstrap circuit.

[0026] The input voltage regulator circuit includes: a linear voltage regulator, a drive power supply, a feedback network, and a filter capacitor; The input terminal of the linear voltage regulator is coupled to the driving power supply, and the input voltage of the driving power supply is VIN. In this embodiment, if the linear voltage regulator is a linear voltage regulator chip, the input voltage needs to be 1V-2V higher than the required voltage of the PWM controller and PWM driver in the transformer driving circuit, and a certain current margin is reserved to provide a stable DC input to the transformer driving circuit.

[0027] The linear voltage regulator is connected to ground via a coupled feedback network, which consists of a first resistor R1 and a second resistor R2. The first resistor R1 and the second resistor R2 are connected in series, and the first resistor R1 and the second resistor R2 are connected in parallel with the linear voltage regulator. In this embodiment, when it is necessary to adjust the operating voltage of the transformer drive circuit, it is only necessary to adjust the resistance values ​​of the first resistor R1 and the second resistor R2 in the feedback network that are connected in conjunction with the linear voltage regulator.

[0028] The transformer drive circuit includes: a PWM controller, a PWM driver, an RC charging and discharging circuit, a transformer, and a first capacitor C12; The output of the linear regulator is connected to the power supply of the PWM controller and PWM driver via a coupling filter capacitor C1. In this embodiment, the voltage output by the drive power supply is regulated by the linear regulator and converted into the power supply VCC used by the transformer drive circuit to power the PWM controller and PWM driver.

[0029] The PWM controller is grounded via a coupled RC charging and discharging circuit, which includes a third resistor R3, a second capacitor C2, and a third capacitor C3. The output frequency of the PWM controller is determined by the third resistor R3, the second capacitor C2, and the third capacitor C3. The PWM frequency output by the PWM controller can be changed by adjusting the resistance value of the third resistor R3 and the capacitance values ​​of the second capacitors C2 and C3.

[0030] The output terminal of the PWM controller is connected to the PWM driver. The PWM controller outputs a PWM control signal and loads it onto the PWM driver. The output terminal of the PWM driver is connected to the transformer, and the primary coil of the transformer is connected to the PWM driver through the first capacitor C12. In this embodiment, the PWM driver can be replaced by a high-current push-pull circuit to transfer energy to the transformer coil.

[0031] The control method for the transformer drive circuit includes: S101: Receives the PWM signal from the PWM controller through the PWM driver, amplifies the PWM signal, and drives the current to flow on the transformer, transferring energy to the secondary coil of the transformer.

[0032] S102: The PWM driver outputs a high level, causing current to flow from the input terminal of the transformer through the primary coil and the first capacitor C12 to ground, gradually increasing the voltage of the first capacitor C12, storing some energy, and raising the potential of the transformer coil output terminal.

[0033] S103: When the interrupted PWM output is high, the PWM controller outputs a low level, which drives the PWM driver to output a low level. When the potential at the input terminal of the transformer is equal to GND and the potential at the output terminal is equal to the voltage across the first capacitor C12, the current in the primary coil of the transformer flows in reverse, transferring energy to the secondary coil of the transformer.

[0034] The transformer secondary rectifier and filter circuit includes: a first diode D1, a second diode D2, a first bootstrap capacitor C13, and an energy storage capacitor C4. The secondary coil of the transformer is coupled to the first bootstrap capacitor C13 and then connected to the anode of the first diode D1 and the cathode of the second diode D2, respectively. An energy storage capacitor C4 is located between the cathode of the first diode D1 and the anode of the second diode D2. The cathode of the first diode D1 and the anode of the second diode D2 serve as the positive and negative output terminals of the transformer secondary rectifier and filter circuit, respectively, and are connected to the drive output and the negative voltage bootstrap circuit. The transformer secondary rectifier and filter circuit rectifies and filters the transformer output signal before transmitting it to the drive output and the negative voltage bootstrap circuit.

[0035] The control method for the transformer secondary rectifier and filter circuit includes: S201: Set the upper end of the transformer to a high level and the lower end to a low level, so that the current direction of the transformer secondary coil is from bottom to top. The current passes through the first bootstrap capacitor C13, the first diode D1, and the energy storage capacitor C4 and returns to the lower end of the transformer secondary coil. The voltage at the left end of the first bootstrap capacitor C13 and the upper end of the energy storage capacitor C4 will gradually increase, and the current will gradually decrease.

[0036] S202: Set the upper end of the transformer to low level and the lower end to high level, so that the current direction of the transformer secondary coil is from top to bottom. The current flows out of the transformer secondary coil, through the second diode D2, and the first bootstrap capacitor C13 returns to the upper end of the transformer secondary coil. Due to the unidirectional conduction of the first diode D1, no current flows through the energy storage capacitor C4, and the voltage remains unchanged; while the voltage on the first bootstrap capacitor C13 changes from left positive and right negative to left negative and right positive, raising the voltage on the right end of the first bootstrap capacitor C13.

[0037] S203: Set the upper end of the transformer to high level and the lower end to low level again, so that the current direction on the secondary coil of the transformer is from bottom to top again. The voltage at the left end of the first diode D1 is equal to the voltage at the upper end of the secondary coil of the transformer plus the voltage of the first bootstrap capacitor C13, which charges the energy storage capacitor C4.

[0038] The drive output and negative voltage bootstrap circuit includes: input terminal IN+ and input terminal IN-, used to receive input signals; the input terminals IN+ and IN- serve as the input terminals of the drive output and negative voltage bootstrap circuit, respectively coupled to the positive output terminal and negative output terminal of the transformer secondary rectifier filter circuit.

[0039] The drive output and negative pressure bootstrap circuit further includes: a signal processing module and a first output terminal Vg and a second output terminal Vs; wherein, the signal processing module is connected between the input terminal and the output terminal.

[0040] The signal processing module includes: The fourth pull-down resistor R4 is connected to the IN+ pin at one end and to the second output terminal Vs at the other end; the resistance value is set in the range of 1kΩ-10kΩ, and is used to limit the current at the input terminal of the optocoupler OPT.

[0041] The driver optocoupler OPT includes a first MOSFET and a second MOSFET. The source of the first MOSFET is connected to the IN+ pin, and the drain and gate of the first MOSFET are connected to the drain and gate of the second MOSFET, respectively. The source of the second MOSFET is connected to the second output terminal Vs through a third diode D3.

[0042] The fourth diode D4 and the fifth diode D5 are connected in the same direction and are coupled to the output terminal of the optical drive optocoupler OPT. The fourth diode D4 and the fifth diode D5 can be Schottky diodes. They are set at the output terminal of the optical drive optocoupler OPT to quickly respond to signal changes and to rectify and protect the output signal.

[0043] The second bootstrap capacitor C5 is connected at one end to the input terminal IN- and at the other end to the second output terminal Vs.

[0044] The control method for the drive output and the negative voltage bootstrap circuit includes: S301: Drive the optocoupler OPT to output a high level. The input voltage at the input terminal IN+ is connected to the first output terminal Vg through the first MOSFET inside the drive optocoupler OPT. The first output terminal Vg is connected to the gate of the second MOSFET. The current flows through the gate and source of the second MOSFET and the external pull-down fourth resistor R4, and then flows into the second output terminal Vs. It then flows back to the input terminal IN- through the second bootstrap capacitor C5.

[0045] S302: Drive the optocoupler OPT to output a low level. The first output terminal Vg is turned on through the second MOSFET inside the optocoupler OPT, and the gate capacitance Cgs of the second MOSFET is rapidly discharged through the third diode D3.

[0046] In this embodiment, since the lower potential of the second bootstrap capacitor C5 is higher than the upper potential, the driving voltage output by the first output terminal Vg can be less than that of the second output terminal Vs. This can both enable the second MOSFET to discharge and turn off quickly and generate a negative gate voltage, preventing the second MOSFET from being mis-turned on due to the Miller effect.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A MOSFET-based isolated drive circuit system that is easy to control, characterized in that, include: The circuit includes an input voltage regulator circuit, a transformer drive circuit, a transformer secondary rectifier and filter circuit, a drive output circuit, and a negative voltage bootstrap circuit; among which... The input voltage regulator circuit includes: a linear voltage regulator, a drive power supply, a feedback network, and a filter capacitor; The input terminal of the linear voltage regulator is coupled to the drive power supply, which has an input voltage VIN. The linear voltage regulator is connected to ground through a coupled feedback network. The input voltage regulator circuit is used to provide a stable DC input to the transformer drive circuit. The transformer drive circuit includes: a PWM controller, a PWM driver, an RC charging and discharging circuit, a transformer, and a first capacitor; the output terminal of the linear voltage regulator is connected to the power supply terminals of the PWM controller and the PWM driver through a coupling filter capacitor; the PWM controller is grounded through the coupling RC charging and discharging circuit; the output terminal of the PWM controller is connected to the PWM driver, and the PWM controller outputs a PWM control signal which is then applied to the PWM driver; the output terminal of the PWM driver is connected to the transformer, and the primary coil of the transformer is connected to the PWM driver through the first capacitor. The transformer drive circuit is used to generate an isolation power supply for the drive optocoupler OPT in the signal processing module; wherein, the control method of the transformer drive circuit includes the following specific steps: S101: Receives the PWM signal from the PWM controller through the PWM driver, amplifies the PWM signal, and drives the current to flow on the transformer, transferring energy to the secondary coil of the transformer. S102: The PWM driver outputs a high level, causing current to flow from the input terminal of the transformer through the primary coil and the first capacitor to ground, gradually increasing the voltage of the first capacitor, storing some energy, and raising the potential of the transformer coil output terminal; S103: When the interrupt PWM outputs a high level, the PWM controller outputs a low level, which drives the PWM driver to output a low level. When the potential at the input terminal of the transformer is equal to GND and the potential at the output terminal is equal to the voltage across the first capacitor, the current in the primary coil of the transformer flows in reverse, transferring energy to the secondary coil of the transformer. The transformer secondary rectifier and filter circuit includes: a first diode, a second diode, a first bootstrap capacitor, and an energy storage capacitor; wherein, the secondary coil of the transformer is coupled to the first bootstrap capacitor and then connected to the positive terminal of the first diode and the negative terminal of the second diode respectively, and an energy storage capacitor is provided between the negative terminal of the first diode and the positive terminal of the second diode; the negative terminal of the first diode and the positive terminal of the second diode serve as the positive output terminal and the negative output terminal of the transformer secondary rectifier and filter circuit respectively, and are connected to the drive output and the negative voltage bootstrap circuit; the transformer secondary rectifier and filter circuit rectifies and filters the transformer output signal and then transmits it to the drive output and the negative voltage bootstrap circuit; The transformer secondary rectifier and filter circuit is used to rectify and filter the signal output from the transformer drive circuit; wherein, the specific steps of the control method for the transformer secondary rectifier and filter circuit include: S201: Set the upper end of the transformer to a high level and the lower end to a low level, so that the current direction of the transformer secondary coil is from bottom to top. The current passes through the first bootstrap capacitor, the first diode, and the energy storage capacitor and returns to the lower end of the transformer secondary coil. The voltage at the left end of the first bootstrap capacitor and the upper end of the energy storage capacitor will gradually increase, and the current will gradually decrease. S202: Set the upper end of the transformer to low level and the lower end to high level, so that the current direction of the transformer secondary coil is from top to bottom. The current flows out of the transformer secondary coil, through the second diode, and the first bootstrap capacitor returns to the upper end of the transformer secondary coil. Due to the unidirectional conduction of the first diode, no current flows through the energy storage capacitor, and the voltage remains unchanged; while the voltage on the first bootstrap capacitor changes from left positive and right negative to left negative and right positive, raising the voltage on the right end of the bootstrap capacitor. S203: Set the upper end of the transformer to high level and the lower end to low level again, so that the current direction on the secondary coil of the transformer is from bottom to top again. The voltage at the left end of the first diode is equal to the voltage at the upper end of the secondary coil of the transformer plus the voltage of the first bootstrap capacitor, thus charging the energy storage capacitor. The drive output and negative voltage bootstrap circuit includes: input terminal IN+ and input terminal IN-, used to receive input signals; the input terminals IN+ and IN- serve as the input terminals of the drive output and negative voltage bootstrap circuit, respectively coupled to the positive output terminal and negative output terminal of the transformer secondary rectifier filter circuit. The drive output and negative pressure bootstrap circuit further includes: a signal processing module and a first output terminal and a second output terminal; wherein, the signal processing module is connected between the input terminal and the output terminal; The signal processing module includes: a fourth pull-down resistor, a driving optocoupler OPT, a fourth diode, a fifth diode, and a second bootstrap capacitor; The pull-down fourth resistor is connected at one end to the IN+ pin and at the other end to the second output terminal; the driving optocoupler OPT includes a first MOSFET and a second MOSFET, wherein the source of the first MOSFET is connected to the IN+ pin, the drain and gate of the first MOSFET are connected to the drain and gate of the second MOSFET respectively, and the source of the second MOSFET is connected to the second output terminal through a third diode; the fourth diode and the fifth diode are connected in the same direction and are coupled to the output terminal of the driving optocoupler OPT between the fourth diode and the fifth diode; the second bootstrap capacitor is connected at one end to the input terminal IN- and at the other end to the second output terminal; The drive output and negative voltage bootstrap circuit is used to output positive and negative drive signals to the MOSFET in the drive optocoupler OPT; wherein, the specific steps of the control method for the drive output and negative voltage bootstrap circuit include: S301: Drive the optocoupler OPT to output a high level. The input voltage at the input terminal IN+ is connected to the first output terminal through the first MOSFET inside the drive optocoupler OPT. The first output terminal is connected to the gate of the second MOSFET. The current flows through the gate, source, and pull-down fourth resistor of the second MOSFET, and then flows into the second output terminal. It then flows back to the input terminal IN- through the second bootstrap capacitor. S302: Drive the optocoupler OPT to output a low level. The first output terminal is turned on through the second MOSFET inside the optocoupler OPT. The gate capacitance Cgs in the second MOSFET is discharged quickly through the third diode.

2. The easily controllable MOSFET-based isolated drive circuit system according to claim 1, characterized in that: The RC charging and discharging circuit includes: a third resistor, a second capacitor, and a third capacitor; wherein the third resistor is connected in parallel with the second capacitor and the third capacitor, and the second capacitor is connected in parallel with the third capacitor.

3. The easily controllable MOSFET-based isolated drive circuit system according to claim 1, characterized in that: The feedback network consists of a first resistor and a second resistor, wherein the first resistor and the second resistor are connected in series, and the first resistor and the second resistor are connected in parallel with a linear voltage regulator.

4. The easily controllable MOSFET-based isolated drive circuit system according to claim 1, characterized in that: In order to provide a stable DC input to the transformer drive circuit, the input voltage of the linear regulator is 1V-2V higher than the required voltage of the PWM controller and PWM driver in the transformer drive circuit.

5. The easily controllable MOSFET-based isolated drive circuit system according to claim 1, characterized in that: The voltage output by the drive power supply is regulated by a linear voltage regulator and then converted into the power supply VCC used by the transformer drive circuit to power the PWM controller and PWM driver.

6. The easily controllable MOSFET-based isolated drive circuit system according to claim 1, characterized in that: The output frequency of the PWM controller is determined by the third resistor and the second and third capacitors. By adjusting the resistance value of the third resistor and the capacitance values ​​of the second and third capacitors, the output frequency of the PWM controller can be changed.

7. The easily controllable MOSFET-based isolated drive circuit system according to claim 1, characterized in that: The resistance value of the fourth pull-down resistor is set in the range of 1kΩ-10kΩ, and is used to limit the current at the input terminal of the optical drive optocoupler OPT.

8. A MOSFET-based isolated drive circuit system for easy control according to claim 1, characterized in that: The fourth and fifth diodes are Schottky diodes and are located at the output of the optical drive optocoupler (OPT) to respond to signal changes and rectify the output signal.

9. A MOSFET-based isolated drive circuit system for easy control according to claim 1, characterized in that: In order to enable the second MOSFET to discharge and turn off quickly and generate a negative gate voltage, the potential at the lower end of the second bootstrap capacitor is higher than the potential at the upper end, and the drive voltage output by the first output terminal is less than the voltage output by the second output terminal.

10. A MOSFET-based isolated drive circuit system for easy control according to claim 1, characterized in that: The PWM driver can also be replaced with a high-current push-pull circuit to transfer energy to the transformer coil.

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