Push-pull type separated inverter drive circuit

Abstract

The present invention relates to a push-pull isolated inverter driver circuit, which belongs to the high frequency technology field and solves the problems such as dynamic nonlinearity of linear RF pulse power amplifiers. In this circuit, the first and second square-wave DC power sources are respectively input to the opposite polarity end and the same polarity end of the primary coil of the transformer, the opposite polarity end of the first secondary coil of the transformer is connected to the input end of the first clamping backflow prevention module, the output end of the first clamping backflow prevention module is connected to the grid of the first switching transistor, the same polarity end of the first secondary coil and the clamping end of the first clamping backflow prevention module are grounded together with the source of the first switching transistor, the same polarity end of the second secondary coil is connected to the input end of the second clamping backflow prevention module, the output end of the second clamping backflow prevention module is connected to the grid 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 clamping end of the second clamping backflow prevention module and the source of the second switching transistor are connected to the drain of the first switching transistor and are the signal output end of the circuit.

Description

【Technical Field】 【0001】 The present invention relates to the technical field of high frequency, and particularly to a push-pull type separable inverter drive circuit. 【Background Art】 【0002】 High-frequency plasma power supply systems are widely applied in fields such as PECVD chemical vapor deposition and reactive ion etching. The overall structure of a high-frequency plasma power supply system includes a high-frequency power supply, a matching unit, and a chamber load. The high-frequency power supply outputs a power signal to the matching unit, and the matching unit 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 back to the internal main board to adjust the output power (for example, adjusts to approach the recommended reference value P of the power as close as possible by PID calculation). SET The matching unit also performs operations of calculating the input impedance (the total impedance of the matching unit and the chamber load) and impedance matching (modulation of the matching unit itself) according to the input / output power signals, so that the power signal can be efficiently input to the chamber load. 【0003】 Currently, linear RF pulse power amplifiers used in the steady low-frequency band (25 MHz or less) adopt high-voltage switching transistors, and when combined with a bridge inverter, dynamic non-linearity and gain imbalance are likely to occur. 【0004】 Also, in order to meet the requirement of adjusting the output signal power at a fixed frequency, a design with frequency fixation is required, but a design solution that can also adjust the potential is needed. Naturally, the generally adopted bridge inverter has the characteristics of being stable and simple from the perspective of control, but it cannot meet the requirement of adjusting the power in an environment of a fixed frequency. 【Summary of the Invention】 【0005】 In view of the above analysis, the embodiment of the present invention aims to provide a push-pull type isolated inverter drive circuit that solves the problem in conventional linear RF pulse power amplifiers, which are prone to dynamic nonlinearity and gain imbalance and cannot satisfy the requirement of adjusting power in a fixed frequency environment. 【0006】 The present invention includes a transformer, a first switching transistor, a second switching transistor, a first clamping reverse current prevention module, and a second clamping reverse current prevention module. The first square wave DC power supply and the second square wave DC power supply are input to the opposite polarity terminal and the same polarity terminal of the primary coil of the transformer, respectively, and the first and second square wave DC power supplies alternately reach high levels. The opposite polarity terminal of the first secondary coil of the transformer is connected to the input terminal of the first clamping reverse protection module, the output terminal of the first clamping reverse protection module is connected to the grid of the first switching transistor, and the same polarity terminal of the first secondary coil and the clamping terminal of the first clamping reverse protection module are grounded together with the source of the first switching transistor. The present invention provides a push-pull type isolated inverter drive circuit in which the same polarity terminal of the second secondary coil of the transformer is connected to the input terminal of the second clamping reverse current prevention module, the output terminal of the second clamping reverse current prevention module is connected to the grid of the second switching transistor, the drain of the second switching transistor is connected to the power supply, the opposite polarity terminal of the second secondary coil, the clamping terminal of the second clamping reverse current prevention 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 terminal of the circuit. 【0007】 Based on the above solution, the present invention has been further improved as follows. 【0008】 Furthermore, the first clamping reverse current prevention module and the second clamping reverse current prevention module have the same structure and both include a diode, a third switching transistor, and a first resistor. The grid 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, and the drain of the third switching transistor is connected to one end of the first resistor. The other end of the first resistor is connected to the clamping terminal of the first or second clamping reverse current protection module, the grid of the third switching transistor is connected to the input terminal of the first or second clamping reverse current protection module, and the source of the third switching transistor is connected to the output terminal of the first or second clamping reverse current protection module. 【0009】 Furthermore, the 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 and opposite-polarity ends of the first secondary coil. A second RC filter module is connected in parallel between the same-polarity and opposite-polarity ends of the second secondary coil. 【0010】 Furthermore, the first RC filter module includes a second resistor and a first capacitor, The opposite polarity terminal of the first secondary coil is connected to one terminal of the first capacitor, the other terminal of the first capacitor is connected to one terminal of the second resistor, and the other terminal of the second resistor is connected to the same polarity terminal of the first secondary coil. 【0011】 Furthermore, the second RC filter module includes a third resistor and a second capacitor, The same-polarity end of the second secondary coil is connected to one end of the second capacitor, the other end of the second capacitor is connected to one end of the third resistor, and the other end of the third resistor is connected to the opposite-polarity end of the second secondary coil. 【0012】 Furthermore, the circuit further includes a first buffer gate and a second buffer gate, The first buffer gate is connected in series with the opposite polarity terminals of the transformer's primary coil, and the first square wave DC power supply is input to the opposite polarity terminals of the transformer's primary coil via the first buffer gate. The second buffer gate is connected in series with the same polarity terminals of the transformer's primary coil, and the second square wave DC power supply is input to the same polarity terminals of the transformer's primary coil via the second buffer gate. 【0013】 Furthermore, the circuit further includes a third capacitor, which is connected in series between the same-polarity terminals of the primary coil of the transformer and the second buffer gate, or between the opposite-polarity terminals of the primary coil and the first buffer gate. 【0014】 Furthermore, the first and second switching transistors are NMOS transistors, and the third switching transistor is a PMOS 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 at the signal output terminal of the circuit is equal to the potential of the power supply. 【0016】 Furthermore, 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 at the signal output terminal of the circuit is equivalent to ground or zero potential. 【0017】 Compared to the prior art, the present invention can achieve at least one of the following beneficial effects. 【0018】 In the push-pull type isolated inverter drive circuit provided by the present invention, the first square wave DC power supply and the second square wave DC power supply are limited to alternately high levels, and a first clamping reverse current prevention module and a second clamping reverse current prevention module are provided at the output terminals of the first and second secondary coils of the transformer, respectively. This forms voltage and current limits for the subsequent turn-on of the push-pull transistor, effectively controlling the output signal of the push-pull type isolated inverter drive circuit and effectively solving the dynamic nonlinearity and gain imbalance that tend to occur in conventional linear RF pulse power amplifiers. Furthermore, the first and second clamping reverse current prevention modules prevent the push-pull transistor from burning out due to instantaneous high voltage caused by coil short circuits, and also prevent the coil from burning out at high voltage due to the shock of reverse current to the coil. 【0019】 Furthermore, since the modulation of the output potential and output power at the signal output terminal of a push-pull type separated inverter drive circuit is determined by the potential change of the power supply Vs, 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 the effect of modulating the power at a fixed frequency, thereby satisfying the requirement of adjusting power in a fixed-frequency environment. 【0020】 In the present invention, the above-described technical solutions can be further combined with each other to realize more preferred combined solutions. Other features and advantages of the present invention are described later in the specification, and some of the advantages may become apparent from the specification or be grasped through the implementation of the present invention. The object and other advantages of the present invention can be realized and obtained from what is particularly pointed out in the specification and drawings. [Brief explanation of the drawing] 【0021】 The drawings are merely for illustrating specific embodiments and should not be interpreted as limiting the present invention. In all drawings, the same reference numerals indicate the same components. [Figure 1]It is a circuit diagram of a push-pull type separable inverter drive circuit provided by an embodiment of the present invention. [Figure 2] It is a schematic diagram of control waveforms of a first switching transistor MOS1 and a second switching transistor MOS2 in a push-pull type separable inverter drive circuit provided by an embodiment of the present invention. 【Embodiments for Carrying out the Invention】 【0022】 Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings. Here, the drawings form a part of the present application and are for interpreting the principle of the present invention together with the embodiments of the present invention, and are not for limiting the scope of the present invention. 【0023】 A specific embodiment of the present invention discloses a push-pull type separable inverter drive circuit. The circuit diagram is as shown in FIG. 1. The circuit includes a transformer, a first switching transistor MOS1, a second switching transistor MOS2, a first clamping reverse current prevention module, and a second clamping reverse current prevention module. Here, a first square-wave DC power supply and a second square-wave DC power supply are respectively input to the opposite-polarity ends and the same-polarity ends of the primary coil of the transformer. The first square-wave DC power supply and the second square-wave DC power supply alternately become high levels. The opposite-polarity end of the first secondary coil of the transformer is connected to the input end of the first clamping reverse current prevention module. The output end of the first clamping reverse current prevention module is connected to the grid of the first switching transistor MOS1. The same-polarity end of the first secondary coil and the clamping end of the first clamping reverse current prevention 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 clamping reverse current prevention module. The output end of the second clamping reverse current prevention module is connected to the grid of the second switching transistor MOS2. The drain of the second switching transistor MOS2 is connected to the power supply Vs. The opposite-polarity end of the second secondary coil, the clamping end of the second clamping reverse current prevention module, and the source of the second switching transistor MOS2 are connected to the drain of the first switching transistor MOS1, and the drain of the first switching transistor MOS1 is used as the signal output end of the circuit. 【0024】 In this embodiment, both the first switching transistor MOS1 and the second switching transistor MOS2 are push-pull transistors, and the first and second clamping reverse current protection modules are designed to provide voltage and current limiting buffer protection against the ON state of the push-pull transistors. The first and second clumping reverse current protection modules have the same structure and both include a diode, a third switching transistor (clumping transistor), and a first resistor (clumping resistor). Here, the grid 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 clumping terminal of the first or second clumping reverse current protection module, the grid of the third switching transistor is the input terminal of the first or second clumping reverse current protection module, and the source of the third switching transistor is the output terminal of the first or second clumping reverse current protection module. In Figure 1, for distinction, the diode, third switching transistor, and first resistor in the first clumping reverse current protection module are denoted by symbols D1, MOS3, and R1, respectively. In the second clamping reverse current prevention module, the diode, third switching transistor, and first resistor are denoted by symbols D2, MOS4, and R4, respectively. 【0025】 Preferably, the circuit further includes a first RC filter module and a second RC filter module, where the first RC filter module is connected in parallel between the same-polarity and opposite-polarity ends of the first secondary coil, and the 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 the 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 the third resistor R3, and the other end of the third resistor R3 is connected to the opposite-polarity end of the second secondary coil. 【0026】 Preferably, in order to avoid the signals of the first square wave DC power supply and the second square wave DC power supply being excessively weak and unstable, the circuit in this embodiment further includes a first buffer gate and a second buffer gate, where the first buffer gate is connected in series with the opposite polarity terminals of the primary coil of the transformer, and the first square wave DC power supply is input to the opposite polarity terminals of the primary coil of the transformer via the first buffer gate; the second buffer gate is connected in series with the same polarity terminals of the primary coil of the transformer, and the second square wave DC power supply is input to the same polarity terminals of the primary coil of the transformer via the second buffer gate, thereby performing initial in-phase stable amplification of the input signal. 【0027】 Preferably, the circuit in this embodiment further includes a third capacitor C3, which is connected in series between the same-polarity terminals of the primary coil of the transformer and the second buffer gate, or between the opposite-polarity terminals of the primary coil and the first buffer gate, thereby absorbing a portion of the energy of voltage fluctuations and making the voltage input to the primary winding of the transformer more stable. 【0028】 Furthermore, in the specific implementation process, the first switching transistor MOS1 and the second switching transistor MOS2 will be NMOS transistors, and the third switching transistor will be a PMOS transistor. 【0029】 The operation process of the circuit provided by this embodiment will be described below. 【0030】 In the specific implementation process, it should be noted that the first square wave DC power supply and the second square wave DC power supply alternately reach high levels, and the proportion of high levels is determined according to the duty cycle. In some cases, the first square wave DC power supply and the second square wave DC power supply are strictly out of phase with each other. 【0031】 (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, and due to variations in the polarity terminals of the secondary coil, the current direction in the secondary coil of the second set of circuits (a circuit formed by connecting the second secondary coil, the second switching transistor MOS2, the second clamping reverse current prevention module, and the second RC filter module, indicated by symbol 2) is the same as that of the primary coil. No effective potential is formed between the G and S electrodes of the clamping transistor in the second set of circuits, causing the clamping transistor to turn off. An effective potential is formed across both the G and S electrodes of the push-pull transistor, causing the push-pull transistor to turn on. The second secondary coil of the second set of circuits is almost equivalent to a short-circuit path, and the RC filter module provides voltage and current limiting buffer protection against the turn-on of the push-pull transistor. 【0032】 Due to variations in the polarity of the secondary coils, the current direction of the secondary coil in the first set of circuits (a circuit formed by connecting the first secondary coil, the first switching transistor MOS1, the first clumping reverse current prevention module, and the first RC filter module, reference numeral 1) is opposite to that of the primary coil. As a result, no effective potential is formed across the G and S electrodes of the push-pull transistor in the first set of circuits, causing the push-pull transistor to turn off. Conversely, an effective potential is formed across the G and S electrodes of the clumping transistor, causing the clumping transistor to turn on. At the same time, the clumping resistor forms current limiting protection, and the secondary coil, RC filter module, and clumping reverse current prevention module form an internal circulation circuit that does not interfere with the output. 【0033】 In this case, the potential at the signal output terminal is equal to the potential of the power supply Vs. 【0034】 (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 variations in the polarity of the secondary coils, the current direction in the secondary coil of the first circuit is opposite to that of the primary coil. As a result, no effective potential is formed between the G and S electrodes of the clamping transistor in the first circuit, the clamping transistor turns off, while an effective potential is formed between the G and S electrodes of the push-pull transistor, the push-pull transistor turns on, the coils of the first circuit are almost equivalent to a short-circuit path, and the RC filter module provides voltage and current limiting buffer protection against the turning on of the push-pull transistor. 【0035】 Due to variations in the polarity of the secondary coils, the current direction in the secondary coil of the second circuit is the same as that of the primary coil. As a result, no effective potential is formed across the G and S electrodes of the push-pull transistor in the second circuit, causing the push-pull transistor to turn off. Conversely, an effective potential is formed across the G and S electrodes of the clamping transistor, causing the clamping transistor to turn on. Simultaneously, the clamping resistor forms current limiting protection, and the secondary coil, RC filter module, and clamping reverse current prevention module form an internal circulation circuit that does not interfere with the output. 【0036】 In this case, the potential at the signal output terminal is equivalent to ground or zero potential. 【0037】 A schematic diagram of the control waveforms of the first switching transistor MOS1 and the second switching transistor MOS2 in the push-pull isolated inverter drive circuit provided by an embodiment of the present invention is shown in Figure 2. As can be seen from Figure 2, the control waveforms of the first switching transistor MOS1 and the second switching transistor MOS2 maintain an overall opposite 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 push-pull isolated inverter drive circuit 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 push-pull isolated inverter drive circuit is equivalent to ground or zero potential. Therefore, a square wave DC power supply with two timing delay differences can generate a fixed-frequency AC signal with a relatively stable waveform. In the circuit provided by this embodiment, the output potential and output power at the signal output terminal are determined by the potential change of the power supply Vs, and as long as the frequencies of the two input signals (first square wave DC power supply and second square wave DC power supply) are stable, the frequency of the output AC signal is also relatively stable, thus playing a role in modulating the power at a fixed frequency. 【0038】 Those skilled in the art will understand that all or part of the process for implementing the method of the above embodiment can be completed by issuing instructions to the relevant hardware via a computer program, and that the program can be stored in a computer-readable storage medium, where the computer-readable storage medium is a magnetic disk, an optical disk, a read-only memory, or a random-access memory, etc. 【0039】 The foregoing are merely preferred specific embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any changes or substitutions that are readily conceivable to those skilled in the art within the scope of the present invention are all included within the scope of protection of the present invention.

Claims

[Claim 1] It includes a transformer, a first switching transistor, a second switching transistor, a first clamping reverse current prevention module, and a second clamping reverse current prevention module. The first square wave DC power supply and the second square wave DC power supply are input to the opposite polarity terminal and the same polarity terminal of the primary coil of the transformer, respectively, and the first and second square wave DC power supplies alternately become high levels at a fixed frequency. The opposite polarity terminal of the first secondary coil of the transformer is connected to the input terminal of the first clamping reverse current protection module, the output terminal of the first clamping reverse current protection module is connected to the gate of the first switching transistor, and the same polarity terminal of the first secondary coil and the clamping terminal of the first clamping reverse current protection module are grounded together with the source of the first switching transistor. The same-polarity terminals of the second secondary coil of the transformer are connected to the input terminal of the second clamping reverse current protection module, the output terminal of the second clamping reverse current protection 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 terminals of the second secondary coil, the clamping terminal of the second clamping reverse current protection 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 terminal of the circuit. The first clamping reverse current prevention module and the second clamping reverse current prevention module have the same structure and both include a diode, a third switching transistor, and a first resistor. 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, and the drain of the third switching transistor is connected to one end of the first resistor. A push-pull type isolated inverter drive circuit characterized in that the other end of the first resistor is the clamping terminal of the first clamping reverse current prevention module or the second clamping reverse current prevention module, the gate of the third switching transistor is the input terminal of the first clamping reverse current prevention module or the second clamping reverse current prevention module, and the source of the third switching transistor is the output terminal of the first clamping reverse current prevention module or the second clamping reverse current prevention module. [Claim 2] The 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. The push-pull type isolated inverter drive circuit according to claim 1, 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. [Claim 3] The first RC filter module includes a second resistor and a first capacitor, The push-pull type isolated inverter drive circuit according to claim 2, characterized in that the opposite polarity terminal of the first secondary coil is connected to one terminal of the first capacitor, the other terminal of the first capacitor is connected to one terminal of the second resistor, and the other terminal of the second resistor is connected to the same polarity terminal of the first secondary coil. [Claim 4] The second RC filter module includes a third resistor and a second capacitor. The push-pull type isolated inverter drive circuit according to claim 3, characterized in that the same polarity end of the second secondary coil is connected to one end of the second capacitor, the other end of the second capacitor is connected to one end of the third resistor, and the other end of the third resistor is connected to the opposite polarity end of the second secondary coil. [Claim 5] The circuit further includes a first buffer gate and a second buffer gate, The first buffer gate is connected in series with the opposite polarity terminals of the transformer's primary coil, and the first square wave DC power supply is input to the opposite polarity terminals of the transformer's primary coil via the first buffer gate. The push-pull type isolated inverter drive circuit according to claim 1, characterized in that the second buffer gate is connected in series with the same polarity terminal of the primary coil of the transformer, and the second square wave DC power supply is input to the same polarity terminal of the primary coil of the transformer via the second buffer gate. [Claim 6] The push-pull type isolated inverter drive circuit according to claim 5, further comprising a third capacitor, wherein the third capacitor is connected in series between the same polarity terminal of the primary coil of the transformer and the second buffer gate, or between the opposite polarity terminal of the primary coil and the first buffer gate. [Claim 7] The push-pull type isolated inverter drive circuit according to claim 1, characterized in that the first switching transistor and the second switching transistor are NMOS transistors, and the third switching transistor is a PMOS transistor. [Claim 8] A push-pull type isolated inverter drive circuit according to any one of claims 1 to 7, characterized in that 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 at the signal output terminal of the circuit is equal to the potential of the power supply. [Claim 9] The push-pull type isolated inverter drive circuit according to claim 8, characterized in that 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 at the signal output terminal of the circuit is equivalent to ground or zero potential.

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