High frequency power supply push-pull parallel drive output system

Abstract

The present invention discloses a push-pull parallel driving output system for high frequency power supply, which belongs to the high frequency technical field and solves the problem that the prior art lacks a fixed frequency and high power high frequency power output design solution. The system includes a plurality of sets of class D push-pull isolated inverter driving circuits, balancing resistors, a first-order LC filter, and a high frequency stabilizer, the signal output terminal of each set of class D push-pull isolated inverter driving circuits is respectively connected to one end of each balancing resistor, and the other ends of all the balancing resistors are connected to a common center point, forming a star structure, the signal output terminal of each set of class D push-pull isolated inverter driving circuits is further respectively connected to the input terminal of the corresponding first-order LC filter, the output terminals of all the first-order LC filters are connected to a bus output port, which is connected to the high frequency stabilizer and serves as the high frequency signal output terminal of the system.

Description

[Technical Field]

[0001] The present invention relates to the technical field of high frequency, and more particularly to a push-pull type parallel drive output system for high frequency power supplies. [Background technology]

[0002] High frequency plasma power supply systems are widely applied in the fields of PECVD chemical vapor deposition, reactive ion etching, etc. The overall configuration of a high frequency plasma power supply system includes a high frequency power supply, a matching box, and a chamber load. The high frequency power supply outputs a power signal to the matching box, which performs impedance matching and transfers the power signal to the chamber load. Here, the output end of the high frequency power supply measures V / I, and feeds it back to the internal main board to adjust the output power (for example, by PID calculation, the power is adjusted to the recommended reference value P SET The matching circuit also calculates the input impedance (total impedance of the matching circuit and the chamber load) and performs impedance matching (modulation of the matching circuit itself) according to the input / output power signal, allowing the power signal to be input to the chamber load efficiently.

[0003] In practical applications, the requirement for high frequency power output is high, and how to provide a fixed frequency and high power high frequency power output has become an urgent technical problem to be solved. Summary of the Invention

[0004] In view of the above analysis, an embodiment of the present invention aims to provide a push-pull parallel drive output system for high frequency power supplies to solve the problem that the prior art lacks a fixed frequency and high power high frequency power output design solution.

[0005] The present invention provides a push-pull parallel driving output system for high frequency power supplies, comprising: a plurality of sets of class D push-pull isolated inverter driving circuits, a balancing resistor, a first-order LC filter, and a high frequency stabilizer; The signal output terminal of each group of class D push-pull isolated inverter driver circuits is connected to one end of each balancing resistor, and the other ends of all balancing resistors are connected to a common center point, forming a star structure; The signal output terminal of each group of class D push-pull isolated inverter driver is further connected to the input terminal of the corresponding first-order LC filter, and the output terminals of all the first-order LC filters are connected to form a bus output port, which is connected to a high frequency stabilizer; A push-pull parallel driving output system for high frequency power sources is disclosed, in which the bus output port is the high frequency signal output end of the system.

[0006] Preferably, based on the above-mentioned solution, the present invention is further improved as follows.

[0007] Additionally, the system further includes a DC block, where: The bus output port is further connected to the input of a DC block, and the output of the DC block is the high frequency signal output of the system.

[0008] Additionally, the system further includes a high-order LC filter circuit, where: The bus output port is further connected to the input terminal of a high-order LC filter circuit, the output terminal of which serves as the high-frequency signal output terminal of the system.

[0009] Additionally, the system further includes a high order LC filter circuit and a DC block, where: The bus output port is further connected to the input terminal of a high-order LC filter circuit, the output terminal of the high-order LC filter circuit is connected to the input terminal of a DC block, and the output terminal of the DC block is the high-frequency signal output terminal of the system.

[0010] Furthermore, the high-order LC filter circuit is a second-order LC filter, or a second-order LC filter and a third-order LC filter connected in series in this order.

[0011] Furthermore, the class D push-pull isolated inverter driving circuit includes a transformer, a first switching transistor, a second switching transistor, a first backflow prevention clamp module, and a second backflow prevention clamp module; The first square wave DC power supply and the second square wave DC power supply are respectively input to the opposite polarity end and the same polarity end of the primary coil of the transformer, and the first square wave DC power supply and the second square wave DC power supply alternately become high level, The opposite polarity end of the first secondary coil of the transformer is connected to the input end of the first backflow prevention clamp module, the output end of the first backflow prevention clamp module is connected to the gate of the first switching transistor, and the same polarity end of the first secondary coil and the clamp end of the first backflow prevention clamp module are grounded together with the source of the first switching transistor; The same polarity end of the second secondary coil of the transformer is connected to the input end of the second backflow prevention clamp module, the output end of the second backflow prevention clamp module is connected to the gate of the second switching transistor, the drain of the second switching transistor is connected to the power supply, the opposite polarity end of the second secondary coil, the clamp end of the second backflow prevention clamp module, and the source of the second switching transistor are connected to the drain of the first switching transistor, and the drain of the first switching transistor is the signal output end of the class D push-pull isolated inverter driver circuit.

[0012] Furthermore, the first backflow prevention clamp module and the second backflow prevention clamp module have the same structure, and each includes a diode, a third switching transistor, and a first resistor; a gate of the third switching transistor connected to the anode of the diode, a source of the third switching transistor connected to the cathode of the diode, and a drain of the third switching transistor connected to one end of the first resistor; The other end of the first resistor is the clamp end of the first backflow prevention clamp module or the second backflow prevention clamp module, the gate of the third switching transistor is the input end of the first backflow prevention clamp module or the second backflow prevention clamp module, and the source of the third switching transistor is the output end of the first backflow prevention clamp module or the second backflow prevention clamp module.

[0013] Furthermore, the class D push-pull isolated inverter driving circuit further includes a first RC filter module and a second RC filter module; a first RC filter module is connected in parallel between the same polarity end and the opposite polarity end of the first secondary coil; A second RC filter module is connected in parallel between the same polarity end and the opposite polarity end of the second secondary coil.

[0014] Furthermore, NMOS transistors are used as the first and second switching transistors, and a PMOS transistor is used as the third switching transistor.

[0015] Furthermore, when the first square wave DC power supply is at a low level and the second square wave DC power supply is at a high level, the potential of the signal output terminal of the class D push-pull isolated inverter driving circuit is equal to the potential of the power supply; When the first square wave DC power supply is at a high level and the second square wave DC power supply is at a low level, the potential of the signal output terminal of the class D push-pull isolated inverter driving circuit is equal to ground or is at zero potential.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] The push-pull parallel drive output system of high frequency power supply provided by the present invention provides a fixed frequency and high power high frequency power output design solution, and by adopting a combination of multiple sets of Class D push-pull isolated inverter drive circuits and related resonant topologies, the output high frequency signal power is increased and the voltage is constant, effectively expanding the high frequency signal power range that can be provided by the push-pull parallel drive output system of high frequency power supply, and expanding its application scenarios.

[0018] The present invention also provides a preferred design for the Class D push-pull isolated inverter driver. The first and second square-wave DC power supplies are alternately limited to high levels, and a first backflow clamp module and a second backflow clamp module are provided at the output ends of the first and second secondary coils of the transformer to provide voltage and current limits for the subsequent push-pull transistors when turned on. This effectively controls the output signal of the push-pull isolated inverter driver and solves the problems of dynamic nonlinearity and gain imbalance that are common in conventional linear RF pulse power amplifiers. The first and second backflow clamp modules also prevent the push-pull transistors from burning out due to momentary high voltages caused by coil short circuits, and prevent the coils from burning out due to high voltages caused by reverse currents striking the coils. In addition, the output potential and output power modulation of the signal output terminal of the Class D push-pull separated inverter driver are determined by the potential change of the power supply Vs. Therefore, as long as the frequencies of the two input signals are stable, the frequency of the output AC signal will also be relatively stable, achieving power modulation at a fixed frequency, thereby meeting the requirement of power adjustment in a fixed frequency environment.

[0019] In the present invention, the above technical solutions can be further combined with each other to realize more preferred combined solutions. Other features and advantages of the present invention will be set forth in the following specification, and in part will be apparent from the specification or may be learned by practice of the invention. The objectives and other advantages of the present invention may be realized and obtained by what is particularly pointed out in the specification and drawings. [Brief explanation of the drawings]

[0020] The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, and like reference numerals refer to like elements in all drawings. [Figure 1] 1 is a circuit diagram of a push-pull parallel driving output system for high frequency power sources provided by an embodiment of the present invention; [Figure 2] 1 is a schematic diagram of the configuration of a push-pull parallel drive output system for high frequency power sources provided by an embodiment of the present invention; [Figure 3] 1 is a circuit diagram of a class D push-pull isolated inverter driving circuit provided by an embodiment of the present invention; [Figure 4] 3 is a schematic diagram of the control waveforms of the first switching transistor MOS1 and the second switching transistor MOS2 in the class D push-pull isolated inverter driving circuit provided by the embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0021] Preferred embodiments of the present invention will now be described in detail with reference to the drawings, which constitute a part of this application and are intended to explain the principles of the present invention together with the embodiments of the present invention, but are not intended to limit the scope of the present invention.

[0022] A specific embodiment of the present invention discloses a push-pull parallel driving output system for high frequency power sources, which is realized by combining multiple sets of class D push-pull power amplifiers and associated resonant topologies, and its circuit diagram is shown in Figure 1 and its schematic diagram is shown in Figure 2. The system includes multiple sets of class D push-pull isolated inverter drivers, balancing resistors, primary LC filters, and high frequency stabilizers, where the signal output terminal of each set of class D push-pull isolated inverter drivers is connected to one end of each balancing resistor, and the other ends of all the balancing resistors are connected to a common center point (star) to form a star structure, the signal output terminal of each set of class D push-pull isolated inverter drivers is further connected to the input terminal of the corresponding primary LC filter, and the output terminals of all the primary LC filters are connected to a bus output port, which is connected to the high frequency stabilizer and serves as the high frequency signal output terminal of the system.

[0023] In this embodiment, for each class-D push-pull isolated inverter driver, a balancing resistor is connected in parallel with the primary LC filter to limit the current output from the signal output terminal to the primary LC filter in a shunt configuration. Furthermore, when the current from the signal output terminal of the class-D push-pull isolated inverter driver passes through the balancing resistor, temperature changes in the component itself affect the resistance fluctuations. Therefore, when connected in a star configuration, the actual balancing resistor at the output of each class-D push-pull isolated inverter driver is dynamically adjusted. This dynamic adjustment is achieved by balancing the corresponding resistance and current of each class-D push-pull isolated inverter driver output, thereby achieving stable voltage and current at each output terminal and producing stable power output. In the above-mentioned high-frequency power supply push-pull parallel-driving output system, the output signal of the class-D push-pull isolated inverter driver is waveform-shaped and filtered by the primary LC filter. In addition, the output terminals of all the first-order LC filters are connected in parallel or in the form of a combiner to bus the signal outputs of each set to form a bus output port.The output level is calibrated by an RF stabilizer to obtain the high-frequency signal output of the above system.

[0024] Preferably, in order to ensure the output quality of the high frequency signal, this embodiment further provides the following optional optimization solution based on the above solution.

[0025] (1) The system also includes a DC block. In this case, the bus output port is further connected to the input end of a DC block, and the output end of the DC block is the high-frequency signal output end of the system. The DC block separates the DC component in the signal and optimizes the output quality of the high-frequency signal. For example, the DC block can be realized by a DC blocking capacitor C.

[0026] (2) The system further includes a high-order LC filter circuit. In this case, the bus output port is further connected to the input end of a high-order LC filter circuit, and the output end of the high-order LC filter circuit serves as the high-frequency signal output end of the system. The high-order LC filter circuit filters out high-order harmonics, thereby effectively ensuring the quality of the output signal. For example, the high-order LC filter circuit is a second-order LC filter, or a second-order LC filter and a third-order LC filter connected in series.

[0027] (3) The system further includes a high-order LC filter circuit and a DC block. In this case, the bus output port is further connected to the input end of a high-order LC filter circuit, the output end of the high-order LC filter circuit is connected to the input end of a DC block, and the output end of the DC block is the high-frequency signal output end of the system. By combining the high-order LC filter circuit and the DC block, it is possible to filter out the high-order harmonics in the signal and separate the DC component in the signal, thereby optimizing the output quality of the high-frequency signal.

[0028] In the specific implementation process, the above basic system design method or various preferred system design methods can be selected according to the high frequency signal output requirements of the actual application scenario.

[0029] In this embodiment, the class-D push-pull isolated inverter driver is a core component for realizing high-frequency signal output. A preferred class-D push-pull isolated inverter driver circuit is shown in FIG. 3, which includes a transformer, a first switching transistor MOS1, a second switching transistor MOS2, a first backflow prevention clamp module, and a second backflow prevention clamp module. The first square-wave DC power supply and the second square-wave DC power supply are respectively input to the opposite polarity end and the same polarity end of the primary coil of the transformer. The first square-wave DC power supply and the second square-wave DC power supply alternately go high. The opposite polarity end of the first secondary coil of the transformer is connected to the input end of the first backflow prevention clamp module, and the output end of the first backflow prevention clamp module is connected to the gate of the first switching transistor MOS1. The same polarity end of the first secondary coil and the clamp end of the first backflow prevention clamp module are grounded together with the source of the first switching transistor MOS1. The same polarity end of the second secondary coil of the transformer is connected to the input end of the second backflow prevention clamp module. The output end of the second backflow prevention clamp module is connected to the gate of the second switching transistor MOS2. The drain of the second switching transistor MOS2 is connected to the power supply. The opposite polarity end of the second secondary coil, the clamp end of the second backflow prevention clamp module and the source of the second switching transistor MOS2 are connected to the drain of the first switching transistor MOS1. The drain of the first switching transistor MOS1 is the signal output end of the class D push-pull isolated inverter driver circuit.

[0030] In this embodiment, the first switching transistor MOS1 and the second switching transistor MOS2 are both push-pull transistors, and the first and second backflow prevention clamp modules are designed to provide voltage and current limiting buffer protection when the push-pull transistors are turned on. The first and second backflow prevention clamp modules have the same structure and each include a diode, a third switching transistor (clamp transistor), and a first resistor (clamp resistor), where the gate of the third switching transistor is connected to the anode of the diode, the source of the third switching transistor is connected to the cathode of the diode, the drain of the third switching transistor is connected to one end of the first resistor, the other end of the first resistor is the clamp node of the first backflow prevention clamp module or the second backflow prevention clamp module, the gate of the third switching transistor is the input node of the first backflow prevention clamp module or the second backflow prevention clamp module, and the source of the third switching transistor is the output node of the first backflow prevention clamp module or the second backflow prevention clamp module. 3, for the sake of distinction, the diode, the third switching transistor, and the first resistor in the first backflow prevention clamp module are respectively designated as D1, MOS3, and R1, and the diode, the third switching transistor, and the first resistor in the second backflow prevention clamp module are respectively designated as D2, MOS4, and R4.

[0031] Preferably, the circuit further comprises a first RC filter module and a second RC filter module, wherein: A first RC filter module is connected in parallel between the same-polarity and opposite-polarity ends of the first secondary coil, and a second RC filter module is connected in parallel between the same-polarity and opposite-polarity ends of the second secondary coil. Specifically, the first RC filter module includes a second resistor R2 and a first capacitor C1, where the opposite-polarity end of the first secondary coil is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is connected to one end of a second resistor R2, and the other end of the second resistor R2 is connected to the same-polarity end of the first secondary coil. The second RC filter module includes a third resistor R3 and a second capacitor C2, where the same-polarity end of the second secondary coil is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is connected to one end of a third resistor R3, and the other end of the third resistor R3 is connected to the opposite-polarity end of the second secondary coil.

[0032] Preferably, in order to prevent the signals of the first square-wave DC power source and the second square-wave DC power source from being too weak and unstable, the circuit in this embodiment further includes a first buffer gate and a second buffer gate, wherein the first buffer gate is connected in series with opposite polarity ends of the primary coil of the transformer, and the first square-wave DC power source is input to the opposite polarity ends of the primary coil of the transformer through the first buffer gate; the second buffer gate is connected in series with the same polarity ends of the primary coil of the transformer, and the second square-wave DC power source is input to the same polarity ends of the primary coil of the transformer through the second buffer gate, so as to perform initial in-phase stable amplification of the input signals.

[0033] Preferably, the circuit in this embodiment further includes a third capacitor C3, which is connected in series between the same polarity end of the primary coil of the transformer and the second buffer gate, or between the opposite polarity end of the primary coil and the first buffer gate, thereby absorbing part of the energy of voltage fluctuations and making the voltage input to the primary winding of the transformer more stable.

[0034] In a specific implementation, the first switching transistor MOS1 and the second switching transistor MOS2 are NMOS transistors, and the third switching transistor is a PMOS transistor.

[0035] The operation process of the circuit provided by this embodiment will be described below.

[0036] In a specific implementation, the first and second square wave DC power sources alternately go high, and the high level ratio is determined according to the duty ratio. In some cases, the first and second square wave DC power sources are strictly in opposite phase to each other.

[0037] (1) The first square wave DC power supply is at a low level, and the second square wave DC power supply is at a high level. In this case, the current in the primary coil is 2->1. Due to the variation in the same polarity end of the secondary coil, the current direction in the secondary coil of the second circuit (the circuit formed by connecting the second secondary coil, the second switching transistor MOS2, the second backflow prevention clamp module, and the second RC filter module, designated 2) is the same as that of the primary coil. No effective potential is formed between the G and S electrodes of the clamp transistor in the second circuit, turning the clamp transistor off. An effective potential is formed across the G and S electrodes of the push-pull transistor, turning the push-pull transistor on. The second secondary coil in the second circuit is approximately a short-circuit path, and the RC filter module provides voltage and current limiting buffer protection when the push-pull transistor is turned on.

[0038] Due to the variation in the same polarity end of the secondary coil, the current direction of the secondary coil in the first circuit (the circuit formed by connecting the first secondary coil, the first switching transistor MOS1, the first backflow prevention clamp module, and the first RC filter module, designated by symbol 1) is opposite to that of the primary coil, and no effective potential is formed across the G and S electrodes of the push-pull transistor in the first circuit, causing the push-pull transistor to turn off. An effective potential is formed across the G and S electrodes of the clamp transistor, causing the clamp transistor to turn on. At the same time, the clamp resistor forms current limiting protection, and the secondary coil, the RC filter module, and the backflow prevention clamp module form an internal circulation circuit that does not interfere with the output.

[0039] In this case, the potential of the signal output terminal is equal to the potential of the power supply Vs.

[0040] (2) The first square wave DC power supply is at a high level, and the second square wave DC power supply is at a low level. In this case, the current in the primary coil is 1->2, and due to the variation in the same polarity end of the secondary coil, the current direction in the secondary coil of the first circuit is opposite to that of the primary coil, so that the G electrode and S electrode of the clamp transistor of the first circuit do not form an effective potential, the clamp transistor is turned off, and the G electrode and S electrode of the push-pull transistor form an effective potential, the push-pull transistor is turned on, the coil of the first circuit is almost equivalent to a short circuit path, and the RC filter module forms a buffer protection of voltage limiting and current limiting when the push-pull transistor is turned on.

[0041] Due to the variation of the same polarity end of the secondary coil, the current direction of the secondary coil of the second circuit is the same as that of the primary coil, and no effective potential is formed across the G electrode and S electrode of the push-pull transistor of the second circuit, so the push-pull transistor is turned off, and an effective potential is formed across the G electrode and S electrode of the clamp transistor, so the clamp transistor is turned on. At the same time, the clamp resistor forms current limiting protection, and the secondary coil, RC filter module and backflow prevention clamp module form an internal circulation circuit that does not interfere with the output.

[0042] In this case, the potential of the signal output terminal corresponds to ground or is zero potential.

[0043] FIG. 4 shows a schematic diagram of the control waveforms of the first and second switching transistors MOS1 and MOS2 in the class-D push-pull isolated inverter driver provided by the embodiment of the present invention. As can be seen from FIG. 4, the control waveforms of the first and second switching transistors MOS1 and MOS2 are generally out of phase. When the first switching transistor MOS1 is off and the second switching transistor MOS2 is on, the potential at the signal output terminal of the class-D push-pull isolated inverter driver is equal to the potential of the power supply Vs. When the first switching transistor MOS1 is on and the second switching transistor MOS2 is off, the potential at the signal output terminal of the class-D push-pull isolated inverter driver is equal to ground or zero. Therefore, two square-wave DC power sources with timing delay differences can generate a fixed-frequency AC signal with a relatively stable waveform. In the Class-D push-pull isolated inverter driver provided in this embodiment, the modulation of the output potential and output power at the signal output terminal is determined by the change in the potential of Vs. As long as the frequencies of the two input signals (the first square-wave DC power supply and the second square-wave DC power supply) are stable, the frequency of the output AC signal will also be relatively stable, fulfilling the role of fixed-frequency power modulation. Based on this, by adopting multiple sets of Class-D push-pull isolated inverter drivers combined with related resonant topologies, the output RF signal power can be increased and the voltage can be stabilized, effectively expanding the RF signal power range that can be provided by the push-pull parallel driving output system of the RF power supply, and expanding its application scenarios.

[0044] It is understood by those skilled in the art that all or part of the processes for implementing the methods of the above embodiments can be completed by issuing instructions to relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random-access memory.

[0045] The above are merely preferred specific embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or replacements that are easily thought of by those skilled in the art within the technical scope described in the present invention are all included in the protection scope of the present invention.

Claims

1. The device includes a plurality of sets of class D push-pull isolated inverter driving circuits, a balancing resistor, a first-order LC filter, and a high-frequency stabilizer; The signal output terminal of each group of class D push-pull isolated inverter driver circuits is connected to one end of each balancing resistor, and the other ends of all balancing resistors are connected to a common center point, forming a star structure; The signal output terminal of each group of class D push-pull isolated inverter driver is further connected to the input terminal of the corresponding first-order LC filter, and the output terminals of all the first-order LC filters are connected to form a bus output port, which is connected to a high frequency stabilizer; A push-pull parallel drive output system for high frequency power sources, characterized in that the bus output port is used as the high frequency signal output terminal of the system.

2. Further comprising a DC block, where:

2. The push-pull parallel driving output system of high frequency power supply according to claim 1, wherein the bus output port is further connected to the input end of a DC block, and the output end of the DC block is the high frequency signal output end of the system.

3. Further comprising a high order LC filter circuit, wherein:

2. The push-pull parallel driving output system of high frequency power supply according to claim 1, wherein the bus output port is further connected to the input end of a high-order LC filter circuit, and the output end of the high-order LC filter circuit is the high frequency signal output end of the system.

4. Further comprising a high order LC filter circuit and a DC block, where:

2. The push-pull parallel driving output system of high frequency power supply according to claim 1, characterized in that the bus output port is further connected to the input end of a high-order LC filter circuit, the output end of the high-order LC filter circuit is connected to the input end of a DC block, and the output end of the DC block is the high frequency signal output end of the system.

5. 5. The push-pull type parallel drive output system of a high frequency power supply according to claim 3, wherein the high-order LC filter circuit is a second-order LC filter or a second-order LC filter and a third-order LC filter connected in series in this order.

6. The class D push-pull isolated inverter driving circuit includes a transformer, a first switching transistor, a second switching transistor, a first backflow prevention clamp module, and a second backflow prevention clamp module; The first square wave DC power supply and the second square wave DC power supply are respectively input to the opposite polarity end and the same polarity end of the primary coil of the transformer, and the first square wave DC power supply and the second square wave DC power supply alternately become high level; The opposite polarity end of the first secondary coil of the transformer is connected to the input end of the first backflow prevention clamp module, the output end of the first backflow prevention clamp module is connected to the gate of the first switching transistor, and the same polarity end of the first secondary coil and the clamp end of the first backflow prevention clamp module are grounded together with the source of the first switching transistor; The push-pull parallel driving output system of high frequency power supply according to any one of claims 1 to 4, characterized in that: the same polarity end of the second secondary coil of the transformer is connected to the input end of the second backflow prevention clamp module, the output end of the second backflow prevention clamp module is connected to the gate of the second switching transistor, the drain of the second switching transistor is connected to the power supply, the opposite polarity end of the second secondary coil, the clamp end of the second backflow prevention clamp module and the source of the second switching transistor are connected to the drain of the first switching transistor, and the drain of the first switching transistor is the signal output end of the class D push-pull isolated inverter driving circuit.

7. the first backflow prevention clamp module and the second backflow prevention clamp module have the same structure, and each includes a diode, a third switching transistor, and a first resistor; a gate of the third switching transistor connected to the anode of the diode, a source of the third switching transistor connected to the cathode of the diode, and a drain of the third switching transistor connected to one end of the first resistor; 7. The push-pull parallel driving output system of a high frequency power supply according to claim 6, wherein the other end of the first resistor is a clamp end of the first backflow prevention clamp module or the second backflow prevention clamp module, the gate of the third switching transistor is an input end of the first backflow prevention clamp module or the second backflow prevention clamp module, and the source of the third switching transistor is an output end of the first backflow prevention clamp module or the second backflow prevention clamp module.

8. The class D push-pull isolated inverter driving circuit further includes a first RC filter module and a second RC filter module; a first RC filter module is connected in parallel between the same polarity end and the opposite polarity end of the first secondary coil; 8. The push-pull type parallel driving output system of high frequency power supply according to claim 7, characterized in that a second RC filter module is connected in parallel between the same polarity end and the opposite polarity end of the second secondary coil.

9. 9. The push-pull type parallel driving output system of high frequency power supplies according to claim 8, wherein the first switching transistor and the second switching transistor are NMOS transistors, and the third switching transistor is a PMOS transistor.

10. When the first square wave DC power supply is at a low level and the second square wave DC power supply is at a high level, the potential of the signal output terminal of the class D push-pull isolated inverter driving circuit is equal to the potential of the power supply; 10. The push-pull parallel driving output system of high frequency power supply as claimed in claim 9, characterized in that, when the first square wave DC power supply is high level and the second square wave DC power supply is low level, the potential of the signal output terminal of said class D push-pull isolated inverter driving circuit is equal to ground or is zero potential.

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