Push-pull isolated inverter drive circuit

Abstract

The present application belongs to the technical field of radio frequency, relates to a push-pull isolated inverter drive circuit, and solves problems such as dynamic nonlinearity of a linear RF pulse power amplifier. In the circuit, a first square wave direct current source and a second square wave direct current source are inputted into a non-dotted terminal and a dotted terminal of a primary coil of a transformer, respectively; a non-dotted terminal of a first secondary coil of the transformer is connected to an input end of a first embedded anti-backflow module, and an output end of the first embedded anti-backflow module is connected to a gate electrode of a first switch transistor; a dotted terminal of the first secondary coil, an embedded end of the first embedded anti-backflow module, and a source electrode of the first switch transistor are grounded; a dotted terminal of a second secondary coil is connected to an input end of a second embedded anti-backflow module, an output end of the second embedded anti-backflow module is connected to a gate electrode of a second switch transistor, and a drain electrode of the second switch transistor is connected to a power supply; and a non-dotted terminal of the second secondary coil, an embedded end of the second embedded anti-backflow module, and a source electrode of the second switch transistor are connected to a drain electrode of the first switch transistor and serve as a signal output end of the circuit.

Description

A push-pull isolated inverter drive circuit Technical Field

[0001] The present application relates to the field of radio frequency technology, and in particular to a push-pull isolated inverter drive circuit. Background Art

[0002] RF plasma power systems are widely used in PECVD chemical vapor deposition, reactive ion etching and other fields. The overall architecture of the RF plasma power system includes an RF power supply, a matcher and a chamber load. The RF power supply outputs the power signal to the matcher, which performs impedance matching and transfers the power signal to the chamber load. Among them, the V / I measurement is performed at the output end of the RF power supply and fed back to the internal motherboard for output power adjustment (such as adjusting the power to infinitely approach the recommended reference value P through PID calculation). SET ), the matcher also calculates the input impedance (the combined impedance of the matcher and the chamber load) and performs impedance matching (matcher self-modulation) based on the input / output power signal, so that the power signal can be input to the chamber load with higher efficiency.

[0003] Currently, when high-voltage switching tubes are used in linear RF pulse power amplifiers for constant low-frequency bands (below 25 MHz) in combination with bridge inverters, dynamic nonlinearity and gain imbalance are prone to occur.

[0004] At the same time, to meet the need for constant-frequency output signal power regulation, a design solution with both fixed-frequency design and voltage regulation is required. Obviously, the conventional bridge inverter, while stable and simple to control, cannot meet the power regulation requirements in a constant-frequency environment.

[0005] Summary of the Invention

[0006] In view of the above analysis, the embodiments of the present application aim to provide a push-pull isolated inverter drive circuit to solve the problem that the existing linear RF pulse power amplifier is prone to dynamic nonlinearity and gain imbalance, and cannot meet the power adjustment requirements in a fixed frequency environment.

[0007] The present application provides a push-pull isolated inverter drive circuit, which includes a transformer, a first switch tube, a second switch tube, a first embedded anti-backflow module and a second embedded anti-backflow module; wherein,

[0008] The first square wave DC source and the second square wave DC source are respectively input to the opposite-name terminal and the same-name terminal of the primary coil of the transformer; the first square wave DC source and the second square wave DC source are alternately high level;

[0009] The opposite-name end of the first secondary coil of the transformer is connected to the input end of the first embedded anti-backcurrent module, and the output end of the first embedded anti-backcurrent module is connected to the gate of the first switching tube; the same-name end of the first secondary coil, the embedded end of the first embedded anti-backcurrent module and the source of the first switching tube are all grounded;

[0010] The like-name end of the second secondary coil of the transformer is connected to the input end of the second embedded anti-backcurrent module, the output end of the second embedded anti-backcurrent module is connected to the gate of the second switching tube, and the drain of the second switching tube is connected to the power supply; the opposite-name end of the second secondary coil, the embedded end of the second embedded anti-backcurrent module, the source of the second switching tube and the drain of the first switching tube are connected, and the drain of the first switching tube is used as the signal output end of the circuit.

[0011] Based on the above solution, this application also makes the following improvements:

[0012] Furthermore, the first embedded anti-backflow module and the second embedded anti-backflow module have the same structure, both including a diode, a third switch tube and a first resistor; wherein,

[0013] The gate of the third switch tube is connected to the anode of the diode, the source of the third switch tube is connected to the cathode of the diode, and the drain of the third switch tube is connected to one end of the first resistor;

[0014] The other end of the first resistor is used as the embedding end of the first embedding anti-backcurrent module or the second embedding anti-backcurrent module; the gate of the third switching tube is used as the input end of the first embedding anti-backcurrent module or the second embedding anti-backcurrent module; and the source of the third switching tube is used as the output end of the first embedding anti-backcurrent module or the second embedding anti-backcurrent module.

[0015] Furthermore, the circuit further includes a first RC filter module and a second RC filter module; wherein,

[0016] A first RC filter module is connected in parallel between the same-name terminal and the opposite-name terminal of the first secondary coil;

[0017] A second RC filter module is connected in parallel between the same-name terminal and the opposite-name terminal of the second secondary coil.

[0018] Furthermore, the first RC filter module includes a second resistor and a first capacitor; wherein,

[0019] The opposite-name end of the first secondary coil is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected to the same-name end of the first secondary coil.

[0020] Furthermore, the second RC filter module includes a third resistor and a second capacitor; wherein,

[0021] The same-name 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-name end of the second secondary coil.

[0022] Furthermore, the circuit further includes a first phase transmitter and a second phase transmitter; wherein,

[0023] The first phase transformer is connected in series to the opposite-signal terminal of the primary coil of the transformer; the first square wave DC source is input to the opposite-signal terminal of the primary coil of the transformer via the first phase transformer;

[0024] The second phase-matching device is connected in series to the same-name end of the primary coil of the transformer; the second square wave DC source is input to the same-name end of the primary coil of the transformer via the second phase-matching device.

[0025] Furthermore, the circuit further includes a third capacitor; the third capacitor is connected in series between the same-name end of the primary coil of the transformer and the second phase shifter or between the opposite-name end of the primary coil and the first phase shifter.

[0026] Furthermore, the first switch tube and the second switch tube are NMOS tubes; and the third switch tube is PMOS tube.

[0027] Furthermore, when the first square wave DC source is at a low level and the second square wave DC source is at a high level, the potential of the signal output end of the circuit is equal to the potential of the power supply.

[0028] Furthermore, when the first square wave DC source is at a high level and the second square wave DC source is at a low level, the potential of the signal output end of the circuit is equal to ground or zero potential.

[0029] Compared with the prior art, this application can achieve at least one of the following beneficial effects:

[0030] The push-pull isolated inverter drive circuit provided in this application effectively controls the output signal of the push-pull isolated inverter drive circuit by limiting the alternating high-level operation of the first and second square-wave DC sources. The circuit also provides a first and second embedded anti-backcurrent modules at the output terminals of the first and second secondary coils of the transformer. This module limits the voltage and current of the subsequent push-pull transistors, effectively addressing the dynamic nonlinearity and gain imbalance that are common in existing linear RF pulse power amplifiers. Furthermore, the first and second embedded anti-backcurrent modules prevent the push-pull transistors from being burned by the transient high voltage caused by a coil short circuit, while also preventing reverse current from impacting the coils and causing high-voltage burns.

[0031] Furthermore, since the output potential and output power modulation of the signal output terminal of the push-pull isolated inverter drive circuit are 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 fixed-frequency power modulation, thereby meeting the power adjustment requirements in a fixed-frequency environment.

[0032] In this application, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of this application will be described in the subsequent description, and some advantages will become apparent from the description or be understood by practicing this application. The objectives and other advantages of this application can be achieved and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present application. Throughout the drawings, the same reference symbols denote the same components.

[0034] FIG1 is a circuit diagram of a push-pull isolated inverter drive circuit provided in an embodiment of the present application;

[0035] FIG2 is a schematic diagram of control waveforms of the first switch tube MOS1 and the second switch tube MOS2 in the push-pull isolated inverter drive circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present application to illustrate the principles of the present application, and are not used to limit the scope of the present application.

[0037] A specific embodiment of the present application discloses a push-pull isolated inverter drive circuit, the circuit diagram of which is shown in Figure 1. The circuit includes a transformer, a first switch tube MOS1, a second switch tube MOS2, a first embedded anti-backflow module and a second embedded anti-backflow module; wherein the first square wave DC source and the second square wave DC source are respectively input to the opposite-name end and the same-name end of the primary coil of the transformer; the first square wave DC source and the second square wave DC source are alternately high level; the opposite-name end of the first secondary coil of the transformer is connected to the input end of the first embedded anti-backflow module, and the output end of the first embedded anti-backflow module is connected to the first switch tube MOS 1; the same-name end of the first secondary coil, the clamping end of the first clamped backcurrent protection module and the source of the first switch tube MOS1 are all grounded; the same-name end of the second secondary coil of the transformer is connected to the input end of the second clamped backcurrent protection module, the output end of the second clamped backcurrent protection module is connected to the gate of the second switch tube MOS2, and the drain of the second switch tube MOS2 is connected to the power supply Vs; the opposite-name end of the second secondary coil, the clamping end of the second clamped backcurrent protection module, the source of the second switch tube MOS2 and the drain of the first switch tube MOS1 are connected, and the drain of the first switch tube MOS1 is used as the signal output end of the circuit.

[0038] In this embodiment, the first switch tube MOS1 and the second switch tube MOS2 are both push-pull tubes, and the design of the first embedded anti-backflow module and the second embedded anti-backflow module is used to form a buffer protection of voltage and current limiting for the opening of the push-pull tube. The first embedded anti-backflow module and the second embedded anti-backflow module have the same structure, both including a diode, a third switch tube (embedded tube) and a first resistor (embedded resistor); wherein the gate of the third switch tube is connected to the anode of the diode, the source of the third switch tube is connected to the cathode of the diode, and the drain of the third switch tube is connected to one end of the first resistor; the other end of the first resistor is used as the embedded end of the first embedded anti-backflow module or the second embedded anti-backflow module; the gate of the third switch tube is used as the input end of the first embedded anti-backflow module or the second embedded anti-backflow module; the source of the third switch tube is used as the output end of the first embedded anti-backflow module or the second embedded anti-backflow module. In Figure 1, in order to distinguish them, the diode, the third switch tube, and the first resistor in the first embedded anti-backflow module are represented by the symbols D1, MOS3, and R1 respectively. The diode, the third switch tube, and the first resistor in the second embedded backflow prevention module are represented by symbols D2, MOS4, and R4 respectively.

[0039] Preferably, the circuit further includes a first RC filter module and a second RC filter module; wherein the first RC filter module is connected in parallel between the same-name end and the opposite-name end of the first secondary coil; and the second RC filter module is connected in parallel between the same-name end and the opposite-name end of the second secondary coil. Specifically, the first RC filter module includes a second resistor R2 and a first capacitor C1; wherein the opposite-name 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-name end of the first secondary coil. The second RC filter module includes a third resistor R3 and a second capacitor C2; wherein the same-name 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-name end of the second secondary coil.

[0040] Preferably, in order to prevent the signals of the first square wave DC source and the second square wave DC source from being too weak and unstable, the circuit in this embodiment also includes a first phase regulator and a second phase regulator; wherein the first phase regulator is connected in series to the opposite-name ends of the primary coil of the transformer; the first square wave DC source is input to the opposite-name ends of the primary coil of the transformer via the first phase regulator; the second phase regulator is connected in series to the same-name end of the primary coil of the transformer; the second square wave DC source is input to the same-name end of the primary coil of the transformer via the second phase regulator, so as to perform initial in-phase stable amplification on the input signal.

[0041] Preferably, the circuit in this embodiment further includes a third capacitor C3; the third capacitor C3 is connected in series between the same-name end of the primary coil of the transformer and the second phase regulator or in series between the opposite-name end of the primary coil and the first phase regulator to absorb part of the energy of the voltage fluctuation, so that the voltage input to the primary winding of the transformer is more stable.

[0042] In addition, in a specific implementation process, the first switch tube MOS1 and the second switch tube MOS2 are NMOS tubes; and the third switch tube is a PMOS tube.

[0043] The working process of the circuit provided in this embodiment is described below:

[0044] In the specific implementation, it should be noted that the first square wave DC source and the second square wave DC source are alternately high, and the proportion of the high level is determined by the duty cycle. In some cases, the first square wave DC source and the second square wave DC source are strictly in anti-phase with each other.

[0045] (1) The first square wave DC source is low level, and the second square wave DC source is high level

[0046] At this point, the primary coil current is 2->1. Due to the difference in the secondary coil's like-named terminals, the secondary coil current in the second circuit group (the circuit formed by the second secondary coil, the second switching transistor MOS2, the second clamped anti-backcurrent module, and the second RC filter module, labeled ②) flows in the same direction as the primary coil. The G and S poles of the clamped transistor in the second circuit group are not at an effective potential, so the clamped transistor is turned off. However, the G and S poles of the push-pull transistor are at an effective potential, turning it on. The second secondary coil in the second circuit group is effectively a short circuit, and the RC filter module provides voltage and current limiting protection to prevent the push-pull transistor from turning on.

[0047] Due to the difference in the same-name ends of the secondary coil, the current direction of the secondary coil of the first circuit group (the circuit formed by connecting the first secondary coil, the first switching tube MOS1, the first clamping anti-backcurrent module and the first RC filter module, labeled ①) is opposite to that of the primary coil. No effective potential is formed at the G pole and the S pole of the push-pull tube in the first circuit group, the push-pull tube is turned off, and an effective potential is formed at the G pole and the S pole of the clamping tube, and the clamping tube is turned on; at the same time, the clamping resistor forms current limiting protection, and the secondary coil, RC filter module and the clamping anti-backcurrent module form an internal circulation loop that does not interfere with the output.

[0048] At this time, the potential of the signal output terminal is equal to the potential of the power supply Vs.

[0049] (2) The first square wave DC source is high level, and the second square wave DC source is low level

[0050] At this time, the current in the primary coil changes from 1 to 2. Due to the difference in the like-name terminals of the secondary coils, the current direction of the secondary coil in the first circuit group is opposite to that of the primary coil. The G and S poles of the clamping transistor in the first circuit group do not form an effective potential, so the clamping transistor is turned off. The G and S poles of the push-pull transistor form an effective potential, so the push-pull transistor is turned on. The coil in the first circuit group is almost equivalent to a short-circuit path. The RC filter module will provide buffer protection by limiting voltage and current when the push-pull transistor is turned on.

[0051] Due to the difference in the like-named ends of the secondary coil, the current direction of the secondary coil of the second group of circuits is the same as that of the primary coil. No effective potential is formed at the G pole and S pole of the push-pull tube of the second group of circuits. The push-pull tube is turned off, and an effective potential is formed at the G pole and S pole of the clamped tube. The clamped tube is turned on, and the clamped resistor forms current limiting protection at the same time. The secondary coil, RC filter module and clamped anti-backcurrent module form an internal circulation loop that does not interfere with the output.

[0052] At this time, the potential of the signal output terminal is equivalent to ground or zero potential.

[0053] A schematic diagram of the control waveforms of the first switch MOS1 and the second switch MOS2 in the push-pull isolated inverter drive circuit provided in an embodiment of the present application is shown in FIG2 . As can be seen from FIG2 , the control waveforms of the first switch MOS1 and the second switch MOS2 remain in anti-phase as a whole. When the first switch MOS1 is turned off and the second switch MOS2 is turned on, the potential of 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 switch MOS1 is turned on and the second switch MOS2 is turned off, the potential of the signal output terminal of the push-pull isolated inverter drive circuit is equal to ground or zero potential. Therefore, by using two square wave DC sources with a time delay difference, an AC signal with a relatively stable waveform and a fixed frequency can be generated. In the circuit provided in this embodiment, the output potential and output power of the signal output terminal are modulated by the potential change of the power supply Vs. As long as the frequencies of the two input signals (the first square wave DC source and the second square wave DC source) are stable, the frequency of the output AC signal will also be relatively stable, thereby achieving the effect of fixed frequency power modulation.

[0054] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related 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.

[0055] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A push-pull isolated inverter drive circuit, characterized in that: The circuit includes a transformer, a first switch tube, a second switch tube, a first embedded anti-backflow module and a second embedded anti-backflow module; wherein, The first square wave DC source and the second square wave DC source are respectively input to the opposite-name end and the same-name end of the primary coil of the transformer; the first square wave DC source and the second square wave DC source are alternately high level; The opposite-name end of the first secondary coil of the transformer is connected to the input end of the first embedded anti-backflow module, and the output end of the first embedded anti-backflow module is connected to the gate of the first switch tube; the same-name end of the first secondary coil, the embedded end of the first embedded anti-backflow module and the source of the first switch tube are all grounded; The same-name end of the second secondary coil of the transformer is connected to the input end of the second embedded anti-backcurrent module, the output end of the second embedded anti-backcurrent module is connected to the gate of the second switch tube, and the drain of the second switch tube is connected to the power supply; the opposite-name end of the second secondary coil, the embedded end of the second embedded anti-backcurrent module, the source of the second switch tube and the drain of the first switch tube are connected, and the drain of the first switch tube is used as the signal output end of the circuit.

2. The push-pull isolation inverter drive circuit according to claim 1, characterized in that: The first embedded anti-backflow module and the second embedded anti-backflow module have the same structure, both of which include a diode, a third switch tube and a first resistor; wherein, The gate of the third switch tube is connected to the anode of the diode, the source of the third switch tube is connected to the cathode of the diode, and the drain of the third switch tube is connected to one end of the first resistor; The other end of the first resistor is used as the embedding end of the first embedded anti-backcurrent module or the second embedded anti-backcurrent module; the gate of the third switch tube is used as the input end of the first embedded anti-backcurrent module or the second embedded anti-backcurrent module; the source of the third switch tube is used as the output end of the first embedded anti-backcurrent module or the second embedded anti-backcurrent module.

3. The push-pull isolation inverter drive circuit according to claim 2, characterized in that: The circuit also includes a first RC filter module and a second RC filter module; wherein, A first RC filter module is connected in parallel between the same-name end and the opposite-name end of the first secondary coil; A second RC filter module is connected in parallel between the same-name end and the opposite-name end of the second secondary coil.

4. The push-pull isolation inverter drive circuit according to claim 3, characterized in that: The first RC filter module includes a second resistor and a first capacitor; wherein, The opposite-name end of the first secondary coil is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected to the same-name end of the first secondary coil.

5. The push-pull isolation inverter drive circuit according to claim 4, characterized in that: The second RC filter module includes a third resistor and a second capacitor; wherein, The same-name 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-name end of the second secondary coil.

6. The push-pull isolation inverter drive circuit according to claim 1, characterized in that: The circuit further includes a first phase co-inverter and a second phase co-inverter; wherein, The first phase converter is connected in series to the opposite-name end of the primary coil of the transformer; the first square wave DC source is input to the opposite-name end of the primary coil of the transformer via the first phase converter; The second phase comparator is connected in series to the same-name end of the primary coil of the transformer; the second square wave DC source is input to the same-name end of the primary coil of the transformer via the second phase comparator.

7. The push-pull isolation inverter drive circuit according to claim 6, characterized in that: The circuit further comprises a third capacitor; the third capacitor is connected in series between the same-name end of the primary coil of the transformer and the second in-phase device or between the opposite-name end of the primary coil and the first in-phase device.

8. The push-pull isolation inverter drive circuit according to claim 2, characterized in that: The first switch tube and the second switch tube are NMOS tubes; the third switch tube is PMOS tube.

9. The push-pull isolated inverter drive circuit according to any one of claims 1 to 8, characterized in that: When the first square wave DC source is at a low level and the second square wave DC source is at a high level, the potential of the signal output terminal of the circuit is equal to the potential of the power supply.

10. The push-pull isolation inverter drive circuit according to claim 9, characterized in that: When the first square wave DC source is at a high level and the second square wave DC source is at a low level, the potential of the signal output terminal of the circuit is equal to ground or zero potential.

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