High-power linear adjustable power stabilizing circuit with protection function for radio frequency power supply

Abstract

The invention discloses a high-power linear adjustable power stabilizing circuit with a protection function for a radio frequency power supply. The high-power linear adjustable power stabilizing circuit comprises a voltage stabilizing circuit, a sampling circuit, an error amplifying circuit, a differential pressure detection circuit and a differential pressure protection circuit, the voltage stabilizing circuit comprises an input voltage, a first resistor, a second resistor, a voltage stabilizing diode and a voltage stabilizing PMOS tube. A source electrode of the voltage stabilizing PMOS tube is connected with input voltage, a grid electrode is connected with one end of the second resistor, and a drain electrode is output voltage; the first resistor is connected with an input voltage and a grid electrode of the voltage-stabilizing PMOS tube; the positive electrode of the voltage-stabilizing diode is connected with the grid electrode of the voltage-stabilizing PMOS tube, and the negative electrode is connected with input voltage. The power supply is used for stabilizing the output power of the radio frequency power supply, the voltage of the drain electrode of the final-stage power amplifier is controlled mainly through the high-power linear fine adjustable voltage stabilizing circuit, fine adjustment compensation of the output power is achieved, and the purpose of stabilizing the output power is achieved; meanwhile, an input and output voltage difference detection protection function is achieved, and the voltage stabilizing circuit can be prevented from being burnt out under abnormal conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of radio frequency power supply, and in particular relates to a high-power linear adjustable power stabilization circuit of a radio frequency power supply with a protection function. Background Art

[0002] RF power is the driving source for plasma industrial equipment, mainly used for RF sputtering, plasma chemical vapor deposition, and can be used in equipment such as coating, plasma cleaning, and CO2 lasers. The power stability of RF power directly affects the concentration of plasma, and thus directly affects the accuracy of related processes. Especially in the application of the semiconductor production industry, there are high requirements for the accuracy of related processes.

[0003] The stability of the RF power output can be affected by many factors, and the stability of the drain voltage of the final power amplifier tube is one of the most important factors. Only a precisely controllable and stable drain voltage can ensure the stability of the RF power output power and ensure that the output power of the RF power can be finely compensated. Since the power of the final power amplifier tube of the RF power supply is very high, the maximum output power can reach hundreds of watts or even thousands of watts. This high power demand leads to the complexity of circuit design. Summary of the invention

[0004] The purpose of the present invention is to provide a high-power linear adjustable power stabilization circuit with a protection function for a radio frequency power supply, so as to solve the problem of stability of the power output of the radio frequency power supply.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A high-power linear adjustable power stabilization circuit with protection function for radio frequency power supply, comprising: a voltage stabilization circuit, a sampling circuit, an error amplification circuit, a voltage difference detection circuit and a voltage difference protection circuit;

[0007] The voltage stabilizing circuit includes an input voltage VDin, a first resistor, a second resistor, a voltage stabilizing diode and a voltage stabilizing PMOS tube; the source of the voltage stabilizing PMOS tube is connected to the input voltage VDin, the gate is connected to one end of the second resistor, and the drain is the output voltage VDout; the first resistor connects the input voltage VDin and the gate of the voltage stabilizing PMOS tube; the positive electrode of the voltage stabilizing diode is connected to the gate of the voltage stabilizing PMOS tube, and the negative electrode is connected to the input voltage VDin;

[0008] The sampling circuit includes a fourth resistor and a seventh resistor; the output voltage VDout is grounded through the fourth resistor and the seventh resistor;

[0009] The error amplifier circuit includes a reference voltage VRef, a sixth resistor, a first operational amplifier, a fifth resistor, and a second NPN transistor; the reference voltage VRef is connected to the non-inverting input terminal of the first operational amplifier, and the connection point between the fourth resistor and the seventh resistor is connected to the inverting input terminal of the first operational amplifier through the sixth resistor; the output terminal of the first operational amplifier is connected to the base of the second NPN transistor through the fifth resistor, the collector of the second NPN transistor is connected to the other end of the second resistor, and the emitter of the second NPN transistor is grounded;

[0010] A voltage difference detection circuit, used for detecting the voltage difference between the input voltage VDin and the output voltage VDout;

[0011] The voltage difference protection circuit includes a protection voltage VPro, a second operational amplifier, a thirteenth resistor, a diode and an eighth resistor; the voltage difference is connected to the non-inverting input terminal of the second operational amplifier, and the protection voltage VPro is connected to the inverting input terminal of the second operational amplifier; the output terminal of the second operational amplifier is grounded through the thirteenth resistor, and the output terminal of the second operational amplifier is also connected to the positive electrode of the diode, and the negative electrode of the diode is connected to the base of the second NPN transistor through the eighth resistor.

[0012] Furthermore, the voltage stabilizing circuit also includes a first capacitor, a second capacitor and a polarity capacitor; the drain of the voltage stabilizing PMOS tube is grounded through the first capacitor, the second capacitor and the polarity capacitor, wherein the positive electrode of the polarity capacitor is connected to the drain of the voltage stabilizing PMOS tube, and the negative electrode of the polarity capacitor is grounded.

[0013] Furthermore, the error amplifier circuit also includes a third resistor, a fourth capacitor, a fifth capacitor and a tenth resistor; the non-inverting input terminal of the first operational amplifier is connected to the collector of the second NPN transistor through the fourth capacitor and the third resistor, and the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the fifth capacitor and the tenth resistor.

[0014] Furthermore, the error amplifying circuit also includes a ninth resistor; the base of the second NPN transistor is grounded through the ninth resistor.

[0015] Furthermore, the voltage difference detection circuit includes a twelfth resistor, a seventeenth resistor, a third operational amplifier, a nineteenth resistor, a fourth operational amplifier and a twenty-third resistor; the input voltage VDin is connected to the non-inverting input terminal of the fourth operational amplifier through the twelfth resistor; the output voltage VDout is connected to the non-inverting input terminal of the third operational amplifier through the seventeenth resistor, the inverting input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier, and the output terminal of the third operational amplifier is also connected to the inverting input terminal of the fourth operational amplifier through the nineteenth resistor; the twenty-third resistor is connected to the inverting input terminal of the fourth operational amplifier and the output terminal of the fourth operational amplifier; the output terminal of the fourth operational amplifier is the voltage difference between the input voltage VDin and the output voltage VDout.

[0016] Furthermore, the voltage difference detection circuit also includes a fourteenth resistor and a twenty-first resistor; the non-inverting input terminal of the fourth operational amplifier is grounded through the fourteenth resistor, and the non-inverting input terminal of the third operational amplifier is grounded through the twenty-first resistor.

[0017] Furthermore, the circuit for generating the protection voltage VPro includes a VCC voltage, an eleventh resistor, a fifteenth resistor, a sixteenth resistor, a third NPN transistor, an eighteenth resistor, a twentieth resistor and a twenty-second resistor; the VCC voltage is grounded through the eleventh resistor and the fifteenth resistor, the connection point between the eleventh resistor and the fifteenth resistor is connected to the collector of the third NPN transistor through the sixteenth resistor, and the emitter of the third NPN transistor is grounded; the input voltage VDin is grounded through the eighteenth resistor and the twenty-second resistor, the connection point between the eighteenth resistor and the twenty-second resistor is connected to the base of the third NPN transistor through the twentieth resistor; the protection voltage VPro is drawn out from the connection point between the eleventh resistor and the fifteenth resistor.

[0018] A radio frequency power supply comprises the radio frequency power supply high-power linear adjustable power stabilization circuit with protection function described in any one of the above.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] The present invention is used to stabilize the output power of a radio frequency power supply. It mainly controls the drain voltage of a final power amplifier through a high-power linear finely adjustable voltage stabilizing circuit, thereby realizing fine adjustment and compensation of the output power and achieving the purpose of stabilizing the output power. At the same time, it has an input-output voltage difference detection and protection function, which can prevent the voltage stabilizing circuit from burning out under abnormal circumstances. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a block diagram of a high-power linear adjustable power stabilization circuit of the present invention;

[0022] Figure 2 This is a high-power linear adjustable power stabilization circuit diagram of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] The high-power linear adjustable power stabilization circuit of the radio frequency power supply with protection function of the present invention is as follows: Figure 1 and Figure 2As shown, it includes: a voltage stabilizing circuit, a sampling circuit, an error amplifying circuit, a voltage difference detecting circuit and a voltage difference protecting circuit.

[0025] The voltage stabilizing circuit includes an input voltage VDin, a first resistor R1, a second resistor R2, a voltage stabilizing diode D1 and a voltage stabilizing PMOS tube; the source of the voltage stabilizing PMOS tube is connected to the input voltage VDin, the gate is connected to one end of the second resistor R2, and the drain is the output voltage VDout; the first resistor R1 connects the input voltage VDin and the gate of the voltage stabilizing PMOS tube; the positive electrode of the voltage stabilizing diode D1 is connected to the gate of the voltage stabilizing PMOS tube, and the negative electrode is connected to the input voltage VDin.

[0026] The sampling circuit includes a fourth resistor R4 and a seventh resistor R7; the output voltage VDout is grounded through the fourth resistor R4 and the seventh resistor R7.

[0027] The error amplifier circuit includes a reference voltage VRef, a sixth resistor R6, a first operational amplifier, a fifth resistor R5 and a second NPN transistor Q2; the reference voltage VRef is connected to the non-inverting input terminal of the first operational amplifier, and the connection point between the fourth resistor R4 and the seventh resistor R7 is connected to the inverting input terminal of the first operational amplifier through the sixth resistor R6; the output terminal of the first operational amplifier is connected to the base of the second NPN transistor Q2 through the fifth resistor R5, the collector of the second NPN transistor Q2 is connected to the other end of the second resistor R2, and the emitter of the second NPN transistor Q2 is grounded.

[0028] A voltage difference detection circuit is used to detect the voltage difference between an input voltage VDin and an output voltage VDout; the voltage difference detection circuit comprises a twelfth resistor R12, a seventeenth resistor R17, a third operational amplifier, a nineteenth resistor R19, a fourth operational amplifier and a twenty-third resistor R23; the input voltage VDin is connected to the non-inverting input terminal of the fourth operational amplifier through the twelfth resistor R12; the output voltage VDout is connected to the non-inverting input terminal of the third operational amplifier through the seventeenth resistor R17, the inverting input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier, and the output terminal of the third operational amplifier is also connected to the inverting input terminal of the fourth operational amplifier through the nineteenth resistor R19; the twenty-third resistor R23 is connected to the inverting input terminal of the fourth operational amplifier and the output terminal of the fourth operational amplifier; the output terminal of the fourth operational amplifier is the voltage difference between the input voltage VDin and the output voltage VDout. Furthermore, the voltage difference detection circuit also includes a fourteenth resistor R14 and a twenty-first resistor R21; the non-inverting input terminal of the fourth operational amplifier is grounded through the fourteenth resistor R14, and the non-inverting input terminal of the third operational amplifier is grounded through the twenty-first resistor R21.

[0029] The voltage difference protection circuit includes a protection voltage VPro, a second operational amplifier, a thirteenth resistor R13, a diode D2 and an eighth resistor R8; the voltage difference is connected to the non-inverting input terminal of the second operational amplifier, and the protection voltage VPro is connected to the inverting input terminal of the second operational amplifier; the output terminal of the second operational amplifier is grounded through the thirteenth resistor R13, and the output terminal of the second operational amplifier is also connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 is connected to the base of the second NPN transistor Q2 through the eighth resistor R8.

[0030] In this embodiment, the voltage stabilizing circuit also includes a first capacitor C1, a second capacitor C2 and a polarity capacitor C3; the drain of the voltage stabilizing PMOS tube is grounded through the first capacitor C1, the second capacitor C2 and the polarity capacitor C3, wherein the positive electrode of the polarity capacitor C3 is connected to the drain of the voltage stabilizing PMOS tube, and the negative electrode of the polarity capacitor C3 is grounded for power supply filtering.

[0031] In this embodiment, the voltage-stabilizing PMOS tube includes a PMOS tube Q1 and a bidirectional breakdown diode; the bidirectional breakdown diode is connected to the source and gate of the PMOS tube Q1.

[0032] In this embodiment, the error amplifier circuit further includes a third resistor R3, a fourth capacitor C4, a fifth capacitor C5 and a tenth resistor R10; the in-phase input terminal of the first operational amplifier is connected to the collector of the second NPN transistor Q2 through the fourth capacitor C4 and the third resistor R3, and the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the fifth capacitor C5 and the tenth resistor R10 for loop filtering. Further, the error amplifier circuit further includes a ninth resistor R9; the base of the second NPN transistor Q2 is grounded through the ninth resistor R9.

[0033] In this embodiment, the circuit for generating the protection voltage VPro includes a VCC voltage, an eleventh resistor R11, a fifteenth resistor R15, a sixteenth resistor R16, a third NPN transistor Q3, an eighteenth resistor R18, a twentieth resistor R20 and a twenty-second resistor R22; the VCC voltage is grounded through the eleventh resistor R11 and the fifteenth resistor R15, the connection point between the eleventh resistor R11 and the fifteenth resistor R15 is connected to the collector of the third NPN transistor Q3 through the sixteenth resistor R16, and the emitter of the third NPN transistor Q3 is grounded; the input voltage VDin is grounded through the eighteenth resistor R18 and the twenty-second resistor R22, the connection point between the eighteenth resistor R18 and the twenty-second resistor R22 is connected to the base of the third NPN transistor Q3 through the twentieth resistor R20; the protection voltage VPro is derived from the connection point between the eleventh resistor R11 and the fifteenth resistor R15.

[0034] like Figure 1As shown, VDin is the input voltage of the stabilizing circuit, which can be powered by a common high-power AC / DC adjustable DC switching power supply. High-power adjustable DC switching power supply generally has a large voltage regulation step, and the output voltage is caused by large VPP fluctuations and switching harmonics. After VDin passes through the "voltage stabilizing circuit", it can output a stable VDout to power the drain of the final stage power amplifier of the RF power supply.

[0035] like Figure 1 As shown in the figure, VDout is sampled by high-precision, low-temperature drift resistor voltage divider, and then the error is amplified with the reference voltage VRef, and then fed back to the "voltage stabilization circuit" to achieve the function of stabilizing the output voltage. The coefficient of voltage divider sampling determines the multiple relationship between VDout and VRef. VRef uses a high-precision DAC plus an op amp buffer output, and the fine adjustment of VDout can be achieved through the finely adjustable VRef voltage.

[0036] like Figure 1 As shown in the figure, since the drain current of the final stage of the power amplifier is very large, it generally reaches the level of tens of amperes. At this time, the voltage difference between VDin and VDout determines the heat dissipation of the linear "voltage regulator circuit". Therefore, it is necessary to roughly adjust the voltage of VDin so that the voltage difference between VDin and VDout is controlled within the voltage difference and heat dissipation range allowed by the "voltage regulator circuit".

[0037] like Figure 1 As shown, the voltage difference between VDin and VDout is detected through the "voltage difference detection" circuit. If it is found that VDin-VDout exceeds the safe range, the protection circuit is turned on to prevent the "voltage stabilization circuit" from abnormally burning.

[0038] like Figure 1 As shown in the figure, when the "voltage difference protection" circuit detects that VDin-VDout exceeds the safety range, it will immediately start the voltage difference protection function to keep the voltage difference at a set safety value, thereby preventing the "voltage stabilization circuit" from burning out. When VDin-VDout returns to the safety range, the protection circuit can automatically return to the normal working mode. During the normal operation of the power amplifier, the voltage difference protection circuit will not work. This function is generally used in the case of abnormal input and output voltage differences caused by the moment when the power amplifier is started or shut down.

[0039] The present invention is further described below by taking a 1000W RF power supply as an example:

[0040] like Figure 2As shown, VDin is the input voltage of the stabilization circuit, which is powered by Mean Well RSP-2000-48 2000W adjustable DC switching power supply. The voltage adjustment step of RSP-2000-48 is 0.3V, and it is not possible to adjust the voltage finely. The output voltage ripple of RSP-2000-48 reaches 0.3VPP. Calculated based on the drain current of 40A, 40A*0.3V=12W, which means that the voltage fluctuation of 0.3VPP may reach the output power fluctuation of ten watts. After VDin passes through the high-power PMOS "voltage regulator circuit" Q1, it can output a stable VDout to power the drain of the final amplifier of the RF power supply.

[0041] like Figure 2 As shown, VDout is sampled by R4 and R7 high-precision resistor voltage divider, R4 / R7=20. R4 and R7 use 0.1% precision resistors with a temperature drift of 25ppm. VRef uses a 16-bit high-precision DAC and outputs a voltage of [0V, 3V] through an op amp buffer, with a VRef adjustment step of 0.0458mV. Through the R4 and R7 voltage divider sampling coefficients, it can be concluded that VDout=21*VRef, so it can be concluded that the output range of VDout is [0V, 63V], and the adjustment step is 0.961mV. The fine adjustment step of VDout can achieve fine adjustment compensation of the output power of the final power amplifier.

[0042] like Figure 2 As shown in the figure, since the drain current of the final stage of the power amplifier is very large, when the output power is 1000W, the maximum drain current can reach 30A. At this time, the voltage difference between VDin and VDout determines the heat dissipation of the linear "voltage regulator circuit". If the voltage difference between VDin and VDout is equal to 1V, the heat dissipation of the voltage regulator PMOS tube Q1 will reach 30W. The greater the voltage difference, the greater the heat dissipation. Therefore, it is necessary to roughly adjust the voltage of VDin so that the voltage difference between VDin and VDout is controlled within the voltage difference and heat dissipation range allowed by the "voltage regulator circuit".

[0043] like Figure 2 As shown, the voltage difference between VDin and VDout is detected through the "voltage difference detection" circuit. According to the working characteristics of the op amp, the voltage output of VDin-VDout can be achieved by adjusting the resistance values ​​of R12, R14, R17, R21, R19, and R23. VPro is generated by the VCC voltage through precision resistor voltage division. At the same time, VPro is also controlled by VDin. The larger the VDin voltage, the lower the VPro voltage. The voltage range of the protection voltage VPro can be [1V, 3.3V] by adjusting the resistance values ​​of R11, R15, R16, R18, R22, and R20. If it is found that VDin-VDout exceeds the safety range VPro, the protection circuit is turned on to prevent the "voltage stabilization circuit" from burning abnormally.

[0044] As Figure 2 shown, when VDin - VDout > VPro, the protection circuit is activated. It controls Q1 through D2 and Q2, making the voltage difference stable at VPro, that is, VDin - VDout = VPro, thereby preventing the PMOS "voltage stabilizing circuit" Q1 from being abnormally burned out. When VDin – VDout < VPro, the protection circuit can automatically return to the normal operating mode, and at this time VDout = 21 * Vref. During the normal operation of the power amplifier, the voltage difference protection circuit does not function. This function is generally used for moments such as the startup or shutdown of the power amplifier, which may cause abnormal voltage differences.

[0045] The present invention also provides a radio frequency power supply, which includes the high-power linear adjustable power stabilization circuit with protection function for the radio frequency power supply described in any one of the above.

[0046] It should be noted that according to the needs of implementation, each step / component described in the present application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0047] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-power linear adjustable power stabilization circuit with protection function for radio frequency power supply, characterized in that: include: Voltage stabilizing circuit, sampling circuit, error amplifying circuit, voltage difference detecting circuit and voltage difference protecting circuit; The voltage stabilizing circuit includes an input voltage VDin, a first resistor, a second resistor, a voltage stabilizing diode and a voltage stabilizing PMOS tube; the source of the voltage stabilizing PMOS tube is connected to the input voltage VDin, the gate is connected to one end of the second resistor, and the drain is the output voltage VDout; the first resistor connects the input voltage VDin and the gate of the voltage stabilizing PMOS tube; the positive electrode of the voltage stabilizing diode is connected to the gate of the voltage stabilizing PMOS tube, and the negative electrode is connected to the input voltage VDin; The sampling circuit includes a fourth resistor and a seventh resistor; the output voltage VDout is grounded through the fourth resistor and the seventh resistor; The error amplifier circuit includes a reference voltage VRef, a sixth resistor, a first operational amplifier, a fifth resistor, and a second NPN transistor; the reference voltage VRef is connected to the non-inverting input terminal of the first operational amplifier, and the connection point between the fourth resistor and the seventh resistor is connected to the inverting input terminal of the first operational amplifier through the sixth resistor; the output terminal of the first operational amplifier is connected to the base of the second NPN transistor through the fifth resistor, the collector of the second NPN transistor is connected to the other end of the second resistor, and the emitter of the second NPN transistor is grounded; A voltage difference detection circuit, used for detecting the voltage difference between the input voltage VDin and the output voltage VDout; The voltage difference protection circuit includes a protection voltage VPro, a second operational amplifier, a thirteenth resistor, a diode and an eighth resistor; the voltage difference is connected to the non-inverting input terminal of the second operational amplifier, and the protection voltage VPro is connected to the inverting input terminal of the second operational amplifier; the output terminal of the second operational amplifier is grounded through the thirteenth resistor, and the output terminal of the second operational amplifier is also connected to the positive electrode of the diode, and the negative electrode of the diode is connected to the base of the second NPN transistor through the eighth resistor.

2. The high-power linear adjustable power stabilization circuit with protection function of radio frequency power supply according to claim 1 is characterized in that: The voltage stabilizing circuit also includes a first capacitor, a second capacitor and a polar capacitor; the drain of the voltage stabilizing PMOS tube is grounded through the first capacitor, the second capacitor and the polar capacitor, wherein the positive electrode of the polar capacitor is connected to the drain of the voltage stabilizing PMOS tube, and the negative electrode of the polar capacitor is grounded.

3. The high-power linear adjustable power stabilization circuit with protection function of radio frequency power supply according to claim 1 is characterized in that: The error amplifier circuit also includes a third resistor, a fourth capacitor, a fifth capacitor and a tenth resistor; the non-inverting input terminal of the first operational amplifier is connected to the collector of the second NPN transistor through the fourth capacitor and the third resistor, and the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the fifth capacitor and the tenth resistor.

4. The high-power linear adjustable power stabilization circuit with protection function of radio frequency power supply according to claim 1 is characterized in that: The error amplifying circuit also includes a ninth resistor; the base of the second NPN transistor is grounded through the ninth resistor.

5. The high-power linear adjustable power stabilization circuit with protection function of radio frequency power supply according to claim 1 is characterized in that: The voltage difference detection circuit includes a twelfth resistor, a seventeenth resistor, a third operational amplifier, a nineteenth resistor, a fourth operational amplifier and a twenty-third resistor; the input voltage VDin is connected to the non-inverting input terminal of the fourth operational amplifier through the twelfth resistor; the output voltage VDout is connected to the non-inverting input terminal of the third operational amplifier through the seventeenth resistor, the inverting input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier, and the output terminal of the third operational amplifier is also connected to the inverting input terminal of the fourth operational amplifier through the nineteenth resistor; the twenty-third resistor is connected to the inverting input terminal of the fourth operational amplifier and the output terminal of the fourth operational amplifier; the output terminal of the fourth operational amplifier is the voltage difference between the input voltage VDin and the output voltage VDout.

6. The high-power linear adjustable power stabilization circuit with protection function of radio frequency power supply according to claim 5 is characterized in that: The voltage difference detection circuit also includes a fourteenth resistor and a twenty-first resistor; the non-inverting input terminal of the fourth operational amplifier is grounded through the fourteenth resistor, and the non-inverting input terminal of the third operational amplifier is grounded through the twenty-first resistor.

7. The high-power linear adjustable power stabilization circuit with protection function of radio frequency power supply according to claim 1 is characterized in that: The circuit for generating the protection voltage VPro includes a VCC voltage, an eleventh resistor, a fifteenth resistor, a sixteenth resistor, a third NPN transistor, an eighteenth resistor, a twentieth resistor and a twenty-second resistor; the VCC voltage is grounded through the eleventh resistor and the fifteenth resistor, the connection point between the eleventh resistor and the fifteenth resistor is connected to the collector of the third NPN transistor through the sixteenth resistor, and the emitter of the third NPN transistor is grounded; the input voltage VDin is grounded through the eighteenth resistor and the twenty-second resistor, the connection point between the eighteenth resistor and the twenty-second resistor is connected to the base of the third NPN transistor through the twentieth resistor; the protection voltage VPro is drawn out from the connection point between the eleventh resistor and the fifteenth resistor.

8. A radio frequency power supply, characterized in that: The radio frequency power supply comprises the radio frequency power supply high-power linear adjustable power stabilization circuit with protection function as described in any one of claims 1 to 7.

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