Anti-interference circuit and high-frequency circuit

Abstract

The embodiment of the invention provides an anti-interference circuit and a high-frequency circuit, and the anti-interference circuit comprises a first inductor, a second inductor, and a third inductor. The first inductor is coupled with the second inductor and the third inductor in the same direction, and the first inductor, the second inductor and the third inductor share one magnetic circuit; a coupling dotted terminal of the first inductor is used for connecting a voltage moving point of a high-frequency circuit; the coupling dotted terminals of the second inductor and the third inductor are used for connecting a device connected with a voltage moving point in a high-frequency circuit, the coupling synonym terminals of the second inductor and the third inductor are used for connecting lines to be subjected to anti-interference, and the lines to be subjected to anti-interference are two lines of a connecting device in the high-frequency circuit; when the anti-interference circuit works, the first inductor couples the alternating-current component voltage of the voltage moving point to the second inductor and the third inductor respectively, so that the alternating-current component voltage abuts against the two lines, the alternating-current component voltage in the parasitic capacitor is reduced or even eliminated, and the anti-interference purpose is achieved.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to an anti-interference circuit and a high-frequency circuit. Background Art

[0002] There may be parasitic capacitance between any two conductors in a circuit, such as parasitic capacitance between the signal line in the circuit and the ground, power supply and other wires in the system. When a high-frequency voltage is added to the circuit, it may interfere with the circuit and affect the operation of the circuit, such as causing logic level errors and reduced circuit efficiency. In severe cases, it may cause the circuit to fail to operate. For example, the high-frequency interference current generated enters the circuit with a smaller rated current through the parasitic capacitance, causing damage to the components in the circuit with a smaller rated current, resulting in the paralysis of the entire circuit. Summary of the invention

[0003] In view of this, the present application provides an anti-interference circuit, a high-frequency circuit, a power amplifier circuit, a step-down circuit, a sampling circuit and a power supply to help solve the interference problem caused by the high-frequency moving point voltage in the high-frequency circuit.

[0004] In the first aspect, the embodiment of the present application provides an anti-interference circuit for a high-frequency circuit, including: a first inductor (L1, L11), a second inductor (L2, L12) and a third inductor (L3, L13); the first inductor is in a unidirectional coupling relationship with the second inductor and the third inductor, and the first inductor, the second inductor and the third inductor share a magnetic circuit; the coupling same-name end of the first inductor is used to connect the voltage moving point of the high-frequency circuit (for example, a point on the output line of the bridge circuit); the coupling same-name end of the second inductor and the third inductor is used to connect the device connected to the voltage moving point in the high-frequency circuit, and the coupling opposite-name end is used to connect the line to be interfered with, and the line to be interfered with is two lines connected to the device in the high-frequency circuit. Among them, the device can be a device in the high-frequency circuit whose reference voltage jumps with the voltage moving point, such as a high-side switch tube, a sampling device of a floating voltage (such as a voltage jumping with a reference ground, etc.). The anti-interference circuit can be an input circuit or an output circuit of a signal circuit, the signal circuit can be a control circuit, a drive circuit, etc. of a device, and the anti-interference circuit can also be an output circuit of an auxiliary power supply, etc. The auxiliary power supply may be a power supply circuit for the signal circuit. The device may include an input terminal, a control terminal and an output terminal, wherein the input terminal is connected to the input terminal of the high-frequency circuit, the output terminal is connected to the output terminal of the high-frequency circuit, and the control terminal may be connected to the signal circuit, the drive circuit, etc. The above-mentioned voltage moving point is located at the output terminal of the device or on the line connected to the output terminal. The above-mentioned first inductor may be grounded (such as the reference ground GND1 of the potential of the input terminal of the device). One of the above-mentioned two lines is the reference ground line of the other line. For example, in the two lines of the input line or the output line of the signal circuit, one line (GND2) is the reference ground of the other line (control signal), and in the two lines of the auxiliary power supply output line, one line (GND3) is the reference ground of the other line (power signal).

[0005] When the anti-interference circuit is working, the first inductor, the second inductor and the third inductor have a unidirectional coupling relationship, and the port voltages with the same phase are generated at the coupled same-name ends of the three inductors. Therefore, after the first inductor couples the AC component voltage of the voltage moving point to the second inductor and the third inductor respectively, the AC component voltage can be offset between the two lines, thereby reducing or even eliminating the AC component voltage in the parasitic capacitance, thereby achieving the purpose of anti-interference.

[0006] The ratio of the number of turns of the first inductor, the second inductor and the third inductor can be 1:X:Y (X, Y≤1). When the ratio of the number of turns of the first inductor, the second inductor and the third inductor is 1:1:1, the AC component voltage coupled by the first inductor to the second inductor and the third inductor can be further made to have the same amplitude on the basis of the same phase, thereby eliminating the AC component voltage in the parasitic capacitance, and achieving better effect.

[0007] The above-mentioned anti-interference circuit can be applied to high-frequency circuits such as RF power amplifier circuits, DC converters, AC-DC converters, buck circuits, boost circuits, half-bridge circuits, full-bridge circuits and floating voltage sampling circuits.

[0008] When the above-mentioned anti-interference circuit is applied to a high-frequency circuit whose output current is AC, it may further include a DC blocking capacitor, such as at least one of the first capacitor (C11) and the second capacitor (C12). The first capacitor may be connected to the coupled same-name end of the first inductor, or connected between the coupled opposite-name end of the first inductor and the ground. The second capacitor is connected between the input end of the high-frequency circuit and the coupled opposite-name end of the first inductor. For example, in high-frequency circuits such as radio frequency power amplifier circuits, AC-DC converters, half-bridge circuits, full-bridge circuits, and floating voltage sampling circuits, a DC blocking capacitor connected to the input end of the high-frequency circuit and a DC blocking capacitor connected to the reference ground (GND1) of the potential of the input end of the high-frequency circuit can make the dynamic response effect of the circuit better.

[0009] When there are multiple interference-resistant lines connected to the above-mentioned device (such as a high-side switch tube of a half-bridge circuit in a radio frequency power amplifier connected to a drive circuit and an auxiliary power supply and a control circuit of the drive circuit, and the interference-resistant lines include an output line of the auxiliary power supply, an output line of the control circuit, etc.), the interference-resistant circuit provided in the embodiment of the present application may also include multiple groups of inductors, all of which have a unidirectional coupling relationship with the first inductor and share the same magnetic circuit. For example, the interference-resistant circuit provided in this embodiment, on the basis of the above-mentioned first inductor, the second inductor and the third inductor, also includes a group of inductors: a seventh inductor (L14) and an eighth inductor (L15), and the group of inductors can be arranged on another interference-resistant line connected to the above-mentioned device. For example, the second inductor and the third inductor can be arranged on the output line of the above-mentioned auxiliary power supply, and the seventh inductor and the eighth inductor can be arranged on the signal input or output line of the above-mentioned signal circuit.

[0010] When there are multiple devices in the high-frequency circuit, the anti-interference circuit provided in the embodiment of the present application may also correspond to multiple groups of inductors, and the design of each group of inductors is similar to the first inductor, the second inductor and the third inductor, such as the fourth inductor (L21), the fifth inductor (L22) and the sixth inductor (L23). For example, there are multiple half-bridge circuits in the circuits such as the AC-DC converter, the DC-AC converter, and the radio frequency power amplifier, and each half-bridge circuit may be provided with a group of inductors similar to the first inductor, the second inductor and the third inductor, so as to achieve the purpose that each half-bridge circuit can be anti-interference.

[0011] When there are multiple devices in the high-frequency circuit, and there are multiple interference-resistant lines connected to the devices, the inductors in the interference-resistant circuit provided by the embodiment of the present application can flexibly combine the two groups of inductors. For example, in a high-frequency circuit including multiple half-bridge circuits, each half-bridge circuit includes multiple interference-resistant lines. When multiple groups of inductors similar to the first inductor, the second inductor and the third inductor are set, multiple groups of inductors similar to the seventh inductor and the eighth inductor are set on the multiple interference-resistant lines to meet more interference-resistant requirements.

[0012] In the second aspect, in the high-frequency circuit (such as a direct-to-ac converter, an AC-to-DC converter, a power supply, etc.) provided by the embodiment of the present application, the inductor used to achieve the anti-interference in the first aspect can reuse the original inductor, such as reusing the inductor connected to the high-side transistor in the output matching circuit of the high-frequency circuit as the first inductor, so that it is coupled in the same direction with the second inductor and the third inductor, or coupled in the same direction with the seventh inductor and the eighth inductor, or reusing the inductor connected to the high-side transistor as the fourth inductor, so that it is coupled in the same direction with the fifth inductor and the sixth inductor, etc., to achieve the purpose of anti-interference. For another example, in the DC step-down circuit provided by the embodiment of the present application, the filter inductor in its output circuit is reused as the first inductor, so that it is coupled in the same direction with the second inductor and the third inductor, to achieve the purpose of anti-interference. Moreover, the reuse can simplify the circuit and reduce the cost. Further, the high-frequency circuit provided by the embodiment of the present application can achieve the purpose of separating the signal current or the drive current from the main power current through the first inductor. It should be noted that the anti-interference circuit in the DC step-down circuit provided in the embodiment of the present application (the anti-interference circuit in the first aspect mentioned above) does not require the first capacitor or the second capacitor mentioned above.

[0013] On the third aspect, in the high-frequency circuit (such as a DC-AC converter, an AC-DC converter, a power supply, etc.) provided in the embodiment of the present application, the capacitor used to realize the DC isolation in the first aspect can reuse the original capacitor. For example, in the output matching circuit of the high-frequency circuit, the capacitor connected to the first inductor can be reused as the first capacitor or the second capacitor, thereby improving the dynamic response while achieving the purpose of further simplifying the circuit and reducing costs.

[0014] Furthermore, when there are multiple half-bridge circuits in the above-mentioned high-frequency circuit or high-frequency power amplifier circuit, their auxiliary power supplies can be shared. If the multiple half-bridge circuits all include the above-mentioned anti-interference circuit, the first capacitor or the second capacitor in the anti-interference circuit can also be shared, thereby further simplifying the circuit and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1a A schematic diagram of the structure of an anti-interference circuit provided in an embodiment of the present application;

[0017] Figure 1b for Figure 1a The working principle diagram of the anti-interference circuit shown;

[0018] Figure 2 A schematic diagram of a radio frequency power supply applied to the anti-interference circuit provided in an embodiment of the present application;

[0019] Figure 3 It is a schematic diagram of the class D power amplifier circuit in the radio frequency power supply;

[0020] Figure 4 It is a schematic diagram of anti-interference of a Class D power amplifier circuit in the prior art;

[0021] Figure 5a A schematic diagram of a power amplifier circuit provided in an embodiment of the present application;

[0022] Figure 5b for Figure 5a The schematic diagram of the anti-interference principle of the power amplifier circuit shown;

[0023] Figure 5c A schematic diagram of experimental results provided in an embodiment of the present application;

[0024] Figure 5d Another schematic diagram of experimental results provided in an embodiment of the present application;

[0025] Figure 6a A partial schematic diagram of an anti-interference circuit provided in an embodiment of the present application;

[0026] Figure 6b A partial schematic diagram of another anti-interference circuit provided in an embodiment of the present application;

[0027] Figure 7a A partial schematic diagram of another anti-interference circuit provided in an embodiment of the present application;

[0028] Figure 7b A partial schematic diagram of another anti-interference circuit provided in an embodiment of the present application;

[0029] Figure 7c A partial schematic diagram of another anti-interference circuit provided in an embodiment of the present application;

[0030] Figure 8 A diagram showing the dynamic response effect of a DC blocking capacitor in a high-frequency circuit provided in an embodiment of the present application;

[0031] Fig. 9 A schematic diagram of another high-frequency power amplifier circuit provided in an embodiment of the present application;

[0032] Fig.10 A schematic diagram of another high-frequency power amplifier circuit provided in an embodiment of the present application;

[0033] Fig.11 A schematic diagram of a high-frequency circuit for converting direct current into alternating current provided in an embodiment of the present application;

[0034] Fig.12a A schematic diagram of another high-frequency circuit for converting direct current into alternating current provided in an embodiment of the present application;

[0035] Figure 12b A schematic diagram of a coupled inductor provided in an embodiment of the present application;

[0036] Fig.13a A schematic diagram of an output matching circuit in a high-frequency circuit for converting direct current into alternating current provided in an embodiment of the present application;

[0037] Fig.13b Another schematic diagram of an output matching circuit in a high-frequency circuit for converting direct current into alternating current provided in an embodiment of the present application;

[0038] Fig.14 A schematic diagram of a high-frequency circuit provided in an embodiment of the present application;

[0039] Fig.15 Another high-frequency circuit schematic diagram provided in an embodiment of the present application;

[0040] Fig.16a , Fig.16b and Fig.16c It is a schematic diagram of a converter in a traditional power supply;

[0041] Fig.17 A schematic diagram of another DC step-down circuit provided in an embodiment of the present application;

[0042] Fig.18a A schematic diagram of a floating pressure sampling circuit provided in an embodiment of the present application;

[0043] Fig.18b for Fig.18a Schematic diagram of the anti-interference principle of the circuit shown. DETAILED DESCRIPTION

[0044] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0045] The present application provides an anti-interference circuit for a high-frequency circuit. Figure 1a As shown, it includes: a first inductor (L1), a second inductor (L2) and a third inductor (L3). The first inductor (L1) is in a unidirectional coupling relationship with the second inductor (L2) and the third inductor (L3), and the first inductor, the second inductor and the third inductor share a magnetic circuit.

[0046] The coupled same-name end (the end with a dot) of the first inductor (L1) is used to connect the voltage moving point of the high-frequency circuit (such as Figure 1a The input end of the high-frequency circuit is connected to the busbar. The moving point is the location where the high-frequency jump voltage is generated on the high-frequency circuit. The coupled same-name end (the end with a dot) of the second inductor (L2) and the third inductor (L3) is used to connect the device connected to the voltage moving point in the high-frequency circuit, and the coupled opposite-name end is used to connect the two lines connecting the devices in the high-frequency circuit (such as Figure 1a These two lines can be used to provide power, control signals, etc. to the device.

[0047] When the anti-interference circuit is working, the port voltages generated by the coupled same-name terminals of the first inductor, the second inductor and the third inductor are in phase. Figure 1a and Figure 1b The AC component voltage Va) (as shown in Figure 1b Va, ac) are coupled to the second inductor (L2) and the third inductor (L3) respectively, so that the AC component voltage (Va, ac) is offset between the two lines (11, 12). In the embodiment of the present application, offset means that the AC component voltage of the moving point voltage on the two lines is partially the same or completely the same, and compared with when only one line has an AC component voltage, the AC voltage difference between the two lines is reduced or even zero, thereby reducing the AC current in the parasitic capacitor Cp or even zero, achieving the purpose of protection. Figure 1b As shown, when an electronic component 13 is connected between point A of line 11 and point B of line 12, since Va,ac exists at both points A and B, the AC voltage difference across the electronic component 13 is zero, and thus no AC current is generated in the electronic component 13, and no AC current flows through the parasitic capacitor Cp, which can solve the problem of high-voltage moving point voltage interfering with peripheral control circuits through parasitic capacitance at high frequencies (for example, greater than 10MHz).

[0048] Preferably, the AC component voltages of the first inductor coupled to the second inductor and the third inductor have the same amplitude and phase, so that the AC component voltages are completely offset between the two lines, avoiding AC current from flowing through parasitic capacitance and electronic components connected between the two lines, thereby achieving better protection purposes.

[0049] In the above embodiment, the coil turns ratio of the first inductor, the second inductor and the third inductor can be 1:X:Y. Wherein, X, Y≤1. When X<1, Y<1, the second inductor and the third inductor can be coupled to part of the AC component voltage from the first inductor, so as to reduce the AC current interference caused by part of the AC component voltage. When X=1, Y=1, the port voltages generated by the coupled same-name ends of the first inductor, the second inductor and the third inductor are in the same phase and amplitude, so that the AC component voltage can be completely offset between the two lines.

[0050] As a variation of the above embodiment, another anti-interference circuit embodiment for a high-frequency circuit provided by the present application can add a first capacitor (such as Figure 6a , Figure 6b , 7a Figure 7b and Figure 7c For example, the coupled opposite-name end of the first inductor is connected to the ground GND1 through the first capacitor, or the coupled same-name end of the first inductor is connected to the voltage moving point through the first capacitor.

[0051] As another variation of the above embodiment, another anti-interference circuit embodiment for a high-frequency circuit provided by the present application can add a second capacitor (such as Figure 7a , Figure 7b and Figure 7c The connection mode may be that the coupled opposite-name end of the first inductor is connected to one end of the second capacitor, and the other end of the second capacitor is used to connect a device (such as the input end of the device).

[0052] Another embodiment of an anti-interference circuit for a high-frequency circuit provided in the present application can add a seventh inductor and an eighth inductor on the basis of the above embodiment to protect other lines of the high-frequency circuit. Similar to the second inductor and the third inductor, the first inductor and the newly added seventh inductor and eighth inductor are all in the same-direction coupling relationship, and the seventh inductor and the eighth inductor share the above magnetic circuit. The coupled same-name ends of the seventh inductor and the eighth inductor are used to connect the device connected to the voltage moving point in the high-frequency circuit, and the coupled opposite-name ends are used to connect the other two lines connecting the devices in the high-frequency circuit. When the anti-interference circuit provided in this embodiment is working, when the above two lines (such as Figure 1bWhile protecting the lines 11 and 12 shown in the figure, the first inductor couples the AC component voltage of the above voltage moving point to the seventh inductor and the eighth inductor respectively, so that the AC component voltage offsets each other between the other two lines. Among them, the coil turns ratio of the first inductor, the seventh inductor and the eighth inductor can be 1:X:Y. Among them, X, Y≤1. The anti-interference principle of the first inductor, the seventh inductor and the eighth inductor in this embodiment is similar to that of the above embodiment.

[0053] In the anti-interference circuit provided in the embodiment of the present application, the first inductor can couple and transfer the AC component of the moving-point voltage to a position on the protected circuit that may be interfered by the moving-point voltage. Therefore, the positions and numbers of the two inductors (such as the second inductor and the third inductor, or the seventh inductor and the eighth inductor) coupled in the same direction with the first inductor in the above embodiment are not limited to the description in the above embodiment, and the number of coupled inductors (windings) can be increased or decreased according to actual needs.

[0054] The anti-interference circuit provided in the above embodiment of the present application can be applied to high-frequency circuits such as radio frequency generators (RFG). Radio frequency generators are usually used to generate alternating voltage and current to excite reactive gases to generate plasma. Plasma can be used in the fields of semiconductor production and processing, medical cosmetology, and material processing (such as coating) to perform surface treatment on target materials through processes such as vapor deposition, etching, ion implantation, or annealing.

[0055] RF power supplies for plasma processes (such as Figure 221) shown includes five parts: a main controller, an AC / DC converter (AC / DC converter), a DC converter (DC / DC converter), a DC / AC converter (DC / AC converter) and a directional coupler, which can output high-frequency AC power to an impedance matching box connected to a process chamber. Among them, the main controller is used to control various parts in the RF power supply according to the user's settings and the power detection signal fed back by the directional coupler. The AC / DC converter is used to convert the input AC mains into a target DC voltage under the control of the main controller control signal, and the DC converter is used to convert the output voltage of the previous AC / DC converter into a target power amplifier supply voltage under the control of the main controller control signal. The DC / AC converter is an RF power amplifier circuit, which is used to convert the DC power output by the DC converter into AC power of target frequency and amplitude under the control of the main controller control signal. The directional coupler is used to collect the output power or voltage value of the power amplifier and feed it back to the main controller. The impedance matching box is used to match the plasma impedance in the process chamber to the designed impedance value of the RF power supply, and inject the high-frequency AC power generated by the RF power supply into the process chamber to excite the reaction gas to produce plasma. The frequency of the AC power output by the RF power supply can usually reach megahertz (MHz) or even tens of MHz. In addition, in order to achieve different target processing effects, it is necessary to change the output power of the RF power supply, multi-frequency injection, pulse power duty cycle and mixing methods according to different processes to control the concentration of plasma or the energy of ion bombardment. In order to improve the efficiency of the plasma process equipment, switching power amplifier topologies are often used in RF power supplies with a frequency of MHz, such as Class D, Class E, and Class F power amplifier circuits. The bridge-type Class D switching power amplifier circuit used in the RF power supply is as follows: Figure 3 As shown in the figure, since the Class D power amplifier circuit can clamp the voltage stress of the power amplifier tube to near the bus voltage, it is more suitable for use in scenarios with a large impedance range such as RF power supply compared to resonant topologies such as Class E and Class F. However, since the bridge-type Class D switching power amplifier circuit will be at the midpoint of the bridge arm (such as Figure 3 The point a shown in the figure generates a high-voltage and high-frequency moving point voltage. Therefore, to drive the high-side switch Q1 above, a driving voltage must be superimposed on the midpoint through the driving circuit, as well as an isolated power supply whose reference ground jumps with the midpoint voltage. Figure 3 The Cp shown in the figure may exist between the primary and secondary sides of the transformer as an isolated power supply, and may also exist in the isolation device of the signal circuit that controls the drive circuit ( Figure 3For traditional power supplies with switching frequencies between kilohertz (kHz) and hundreds of kHz, parasitic capacitance is generally in the order of tens of picofarads (pF), which has little effect on the circuit. However, in RF power supplies, the operating frequency of the power amplifier circuit (such as a Class D switching power amplifier) ​​is usually greater than 10MHz, and the fundamental frequency and harmonic frequency can reach greater than 100MHz, which can enter the control system such as the drive circuit, auxiliary power supply, main controller, etc. through parasitic capacitance, affecting the normal operation of the circuit, causing the circuit efficiency to decrease or the logic level to be wrong, and in severe cases even causing damage to the components in the circuit.

[0056] In order to reduce the adverse effects of parasitic capacitance in RF power supplies, existing technologies such as Figure 4 As shown, by connecting common-mode inductors of different frequencies and quantities in series to increase impedance, the common-mode rejection ratio is improved to resist this high-frequency high voltage jump, and block the ground current of the fundamental frequency, harmonics and parasitic resonance. However, in a system with a power of kilowatts (kW), the common-mode voltage is generally greater than 100 volts (V). Therefore, these common-mode inductors will produce huge losses due to the need to withstand huge common-mode voltages, resulting in a significant reduction in circuit efficiency. In addition, the more common-mode inductors there are, the larger the layout area they occupy, which is not conducive to saving costs and space.

[0057] An embodiment of the present application provides a high-frequency power amplifier circuit. By adopting the anti-interference circuit provided in the above embodiment, when the switching frequency is > MHz, the voltage coupling method is used to achieve the purpose of significantly reducing the common-mode voltage (i.e., the moving point voltage) applied to the affected end, and can effectively reduce the number of common-mode inductors that resist the high-frequency jumping high voltage, thereby achieving the purpose of reducing losses and saving costs.

[0058] The present application provides a high-frequency power amplifier circuit implementation example. Figure 5a As shown, it includes a first auxiliary power supply 313, a first drive circuit 312, a first half-bridge circuit 311 and a first anti-interference circuit. The first half-bridge circuit 311 includes a first high-side switch tube Q11 and a first low-side switch tube Q12, the control end of the first high-side switch tube Q11 is connected to the output end of the first drive circuit 312, the output end of the first high-side switch tube Q11 is connected to the input end of the first low-side switch tube Q12, and the output end of the first low-side switch tube Q12 is connected to the reference ground GND1.

[0059] The first anti-interference circuit can be any one of the anti-interference circuits provided in the above embodiments. In this embodiment, the first anti-interference circuit includes a first inductor L11, a second inductor L12, and a third inductor L13. The first inductor L11 is in a unidirectional coupling relationship with the second inductor L12 and the third inductor L13, and the first inductor L11, the second inductor L12, and the third inductor L13 share a magnetic circuit.

[0060] The positive electrode of the first auxiliary power supply 313 is connected to the coupled opposite-name end of the second inductor L12, and the negative electrode is connected to the coupled opposite-name end of the third inductor L13; the coupled same-name end of the second inductor L12 is connected to the power supply access end of the first drive circuit 312 (such as Fig. 9 3121 shown), the coupled same-name end of the third inductor L13 is connected to the power ground end of the first drive circuit 312 (as shown Fig. 9 As shown in 3122 ), the output end of the first high-side switch tube Q11 and the coupled same-name end of the first inductor L11 , and the coupled opposite-name end of the first inductor L11 are grounded.

[0061] In this embodiment, when the high frequency power amplifier circuit is working, Figure 5b As shown, the first inductor L11 couples the AC component voltage Va,ac of the first moving point voltage Va to the second inductor L12 and the third inductor L13 respectively, so that the AC component voltage Va,ac offsets each other between the positive and negative electrodes of the first auxiliary power supply (Vaux), thereby reducing or even eliminating the AC voltage in the parasitic capacitor, reducing or even eliminating the AC current in the parasitic capacitor Cp, that is, reducing or even eliminating the interference current to the chassis ground, thereby achieving the purpose of anti-interference. Compared with the prior art that uses multiple groups of common-mode inductors to eliminate the interference caused by the moving point voltage on the auxiliary power supply line, the technical solution provided in this embodiment not only reduces losses, improves efficiency, but also reduces costs. Figure 5c As shown, in the prior art, when the high-frequency power amplifier circuit is working, the voltage VL11 of L11 is substantially equal to the AC component of Va, and the current Icp flowing through the parasitic capacitor Cp includes an AC component. This embodiment provides a high-frequency power amplifier circuit when working, such as Figure 5d As shown, it can be observed that: VL11 is the AC component voltage Va,ac, and Icp has no AC component current brought by Va,ac except for the extremely high frequency parasitic resonant current.

[0062] Moreover, when the high-frequency power amplifier circuit is working, the first inductor can provide an inductive current to help the half-bridge circuit to draw away the charge of the output capacitor (drain-source capacitor Coss) of the first high-side switch tube and the first low-side switch tube at a frequency greater than MHz, thereby realizing soft switching (i.e., the current that will flow through the main power part, i.e., the current from the moving point a to the output, such as Figure 5a The second inductor and the third inductor will only flow the current of the first drive circuit, which is completely separated from the bus current, so that the drive circuit can use a current far lower than the high-frequency power amplifier output circuit (such as Figure 5a The line group of Ia flows as shown in the figure) can further save costs and space.

[0063] As a variation of the above embodiment, the high frequency power amplifier circuit further includes a first capacitor and / or a second capacitor. Figure 6aAs shown, the coupled opposite-signal end of the first inductor L11 is grounded to GND1 through the first capacitor C11, or as shown in Figure 6b As shown, the coupled same-name end of the first inductor L11 is connected to the moving point through the first capacitor C11, or as shown in Figure 7a As shown, the coupled opposite-signal end of the first inductor L11 is connected to the input end (which may also be a bus) of the first high-side switch Q11 through the second capacitor C12, or as shown in FIG. Figure 7b As shown, the coupled like-name end of the first inductor L11 is connected to the moving point through the first capacitor C11, and the coupled opposite-name end is connected to the input end of the first high-side switch tube Q11 through the second capacitor C12; or as Figure 7c As shown, the coupled opposite-sign terminals of the first circuit L11 are connected to the ground GND1 through the first capacitor C11 and to the bus through the second capacitor C12.

[0064] The first capacitor and the second capacitor are used to isolate the DC component of the moving point voltage. The power amplifier circuit of the anti-interference circuit includes two DC isolation capacitors (the first capacitor and the second capacitor), and its dynamic response is better than the power amplifier circuit of the anti-interference circuit with only one DC isolation capacitor (the first capacitor or the second capacitor). Figure 6a For example, the anti-interference circuit only includes the first capacitor C11. In this case, when the power amplifier circuit is started, the current I(Lx1) of L11 and the voltage V(vcap1) of the capacitor C11 are as follows: Figure 8 As shown in the figure, a large ringing is generated. Figure 7c For example, the anti-interference circuit includes a first capacitor C11 and a second capacitor C12. In this case, when the power amplifier circuit is started, the voltage of the first capacitor C11 and the second capacitor C12 is pre-charged to 0.5×Vbus in advance, the current of L11 becomes I(Lx2), and the voltage of the first capacitor becomes V(vcap2). Figure 8 As shown, I(Lx2) and Vcap2 are both ring-free, so that the output voltage V(vo_sys) of the power amplifier circuit is as follows Figure 8 As shown, there is no significant ringing and the dynamic response is significantly better.

[0065] Another high-frequency power amplifier circuit provided by the present application is implemented as follows Fig. 9 As shown, based on the above high frequency power amplifier circuit embodiment, it also includes a second half bridge circuit 321, a second drive circuit 322, a second auxiliary power supply 323 and a second anti-interference circuit. The second half bridge circuit 321 includes a second high side switch tube Q21 and a second low side switch tube Q22.

[0066] In this embodiment, the first anti-interference circuit includes a first inductor L11, a second inductor L12, a third inductor L13, a first capacitor C11 and a second capacitor C12; the second anti-interference circuit includes a fourth inductor L21, a fifth inductor L22, a sixth inductor L23, a third capacitor C21 and a fourth capacitor C22, and the connection method is similar to the connection of the anti-interference circuit in the first half-bridge circuit 311. The working process of the second half-bridge circuit 321 to generate the dynamic point voltage Vb is similar to that of the first half-bridge circuit 311, and its anti-interference principle is the same as that of the first anti-interference circuit. In addition, the two half-bridge circuits can be independently controlled during operation, for example, the phase and duty cycle of Va and Vb can be adjusted arbitrarily according to the needs of the system.

[0067] As a variation of this embodiment, when the DC component in the moving point voltage (second moving point voltage Vb) of the second half-bridge circuit is the same as the first moving point voltage Va, the first half-bridge circuit and the second half-bridge circuit can share an auxiliary power supply, and the first anti-interference circuit and the second anti-interference circuit can share a group of capacitors. Fig.10 As shown, in the high-frequency power amplifier circuit, the positive and negative electrodes of the first auxiliary power supply 313 are also connected to the coupled opposite-name ends of the fifth inductor L22 and the sixth inductor L23, respectively, and the second half-bridge circuit 321 and the first half-bridge circuit 311 share the first auxiliary power supply 313. The coupled opposite-name ends of the fourth inductor L21 in the second anti-interference circuit are connected to the ground GND1 through the first capacitor C11 and to the bus through the second capacitor C12, and share the first capacitor C11 and the second capacitor C12 with the first anti-interference circuit.

[0068] It should be noted that the high-frequency power amplifier circuit is not limited to the two sets of half-bridge circuits provided in the above embodiments, and corresponding half-bridge circuits and their driving circuits, auxiliary power supplies and anti-interference circuits may actually be added.

[0069] The high-frequency circuit for converting direct current into alternating current provided in the present application may include any one of the anti-interference circuits or high-frequency power amplifier circuits provided in the above embodiments.

[0070] In an embodiment of a high-frequency circuit for converting direct current into alternating current provided by the present application, the signal circuit of the half-bridge circuit can also be protected by an anti-interference circuit. Fig.11 As shown, the high-frequency circuit for converting DC into AC includes, in addition to the first half-bridge circuit and its driving circuit and auxiliary power supply, a first inductor L11, a seventh inductor L14, an eighth inductor L15, a first signal circuit 314 and a first signal isolation circuit 315.

[0071] The first inductor L11 is in a unidirectional coupling relationship with the seventh inductor L14 and the eighth inductor L15, and the first inductor L11, the seventh inductor L14 and the eighth inductor L15 share a magnetic circuit. The signal end of the first signal isolation circuit 315 is connected to the coupling opposite-name end of the seventh inductor L14, and the ground end is connected to the coupling opposite-name end of the eighth inductor L15. The coupling same-name end of the seventh inductor L14 is connected to the signal input end of the first signal circuit 314, and the coupling same-name end of the eighth inductor L15 is connected to the ground end of the first signal circuit 314; the signal output end of the first signal circuit 314 is connected to the signal input end of the first drive circuit 312, and the ground end of the first signal circuit 314 is connected to the power ground end of the first drive circuit 312. The signal output end of the first driving circuit 312 is connected to the control end of the first high-side switch tube Q11, the power ground end of the first driving circuit 312 is connected to the output end of the first high-side switch tube Q11, the input end of the first low-side switch tube Q12 and the coupled same-name end of the first inductor L11, the input end of the first high-side switch tube Q11 is connected to the bus, and the coupled opposite-name end of the first inductor L11 is grounded GND1.

[0072] The anti-interference principle of the first inductor and the seventh inductor and the eighth inductor is similar to the anti-interference principle of the first inductor and the second inductor and the third inductor in the above embodiment. When the high-frequency circuit in this embodiment is working, the first inductor couples the AC component voltage of the moving point voltage to the seventh inductor and the eighth inductor respectively, so that the AC component voltage of the moving point voltage is offset between the signal input terminal, the signal output terminal and the ground terminal of the first signal circuit and the first signal isolation circuit, thereby achieving the purpose of anti-interference.

[0073] Another high-frequency circuit embodiment for converting direct current into alternating current provided by the present application can add an inductor coupled with the first inductor to the auxiliary power supply and the signal circuit at the same time, transfer the AC component voltage of the moving point voltage to the auxiliary power supply and the signal circuit, and reduce or eliminate the AC component voltage on the auxiliary power supply and the signal circuit of the half-bridge circuit. Fig.12a As shown, the first inductor L11 transfers the AC component voltage of Va to the first auxiliary power supply through the second inductor L12 and the third inductor L13, and transfers it to the first signal circuit 314 through the seventh inductor L14 and the eighth inductor L15, thereby eliminating the AC component voltage of Va on the first auxiliary power supply and the first signal circuit. The structure of the first inductor L11, the second inductor L12, the third inductor L13, the seventh inductor L14 and the eighth inductor L15 can be as shown in FIG. Figure 12b shown.

[0074] The high-frequency circuit for converting direct current into alternating current provided in the present application may further include an output matching circuit for matching the impedance (ZL) of the output load to the impedance value required when the bridge circuit is operating.

[0075] In order to further reduce loss and cost, and save space, in another high-frequency circuit for converting direct current into alternating current provided by the present application, the first inductor and / or the fourth inductor, the first capacitor and / or the third capacitor, and the second capacitor and / or the fourth capacitor in the above embodiment are reused in the output matching circuit. Fig.13a The output matching circuit shown reuses the first inductor L11, the fourth inductor L21, the first capacitor C11 and the third capacitor C21. Fig.13b The output circuit shown reuses the second capacitor C12 on the basis of reusing the first inductor L11, the fourth inductor L21, the first capacitor C11 and the third capacitor C21. The coupled opposite-name ends of the first inductor L11 and the fourth inductor L21 are connected to the midpoint of the primary side of the transformer T, and are connected to the input end of the first high-side switch tube Q11 through the second capacitor C12, and are grounded to GND1 through the capacitor C4.

[0076] The anti-interference circuit and output matching circuit provided in the above embodiments can be used in any combination according to actual needs. Fig.14 In the high-frequency circuit shown, the anti-interference circuit and the output matching circuit of the first half-bridge circuit 311 reuse the first inductor L11 and the first capacitor C11, and the anti-interference circuit and the output matching circuit of the second half-bridge circuit 321 reuse the fourth inductor L21 and the third capacitor C21. Fig.15 The high-frequency circuit shown includes two half-bridge circuits and their driving circuits, an auxiliary power supply, a signal circuit and a signal isolation circuit, and also includes an output matching circuit and an anti-interference circuit, and the first inductor L11, the fourth inductor L21, the first capacitor C11, the second capacitor C12 and the third capacitor C12 are shared by the anti-interference circuit and the output matching circuit.

[0077] The anti-interference circuit provided in the above embodiment can be used in the DC converter or AC-DC converter of the RF power supply in addition to the DC converter in the RF power supply. Fig.16b The buck circuit, boost circuit, AC / DC converter (as shown in Fig.16a as shown) and DC-AC converters (as Fig.16c The half-bridge circuit, full-bridge circuit, phase-shifted full-bridge circuit, etc. in the embodiment shown in the figure can all produce high-voltage and high-frequency beating. Therefore, the anti-interference circuit provided in the above embodiment can also be used for AC-DC converters, DC converters and DC-AC converters in traditional power supplies.

[0078] The present application provides a DC step-down circuit implementation example. Fig.17As shown, the anti-interference circuit reuses the inductor in the filter circuit as the first inductor L11, and couples the AC component voltage Vd,ac of the moving point voltage Vd to the second inductor L12 and the third inductor L13. The auxiliary power supply is connected to the drive circuit 17 through the second inductor L12 and the third inductor L13, so that Vd,ac between the positive and negative electrodes of the auxiliary power supply offset each other, thereby achieving the purpose of anti-interference.

[0079] Any of the anti-interference circuits provided in the above embodiments may also be used in a floating voltage (voltage with an unfixed reference ground) sampling scenario.

[0080] For example, a floating pressure sampling circuit provided by the present application is implemented as follows: Fig.18a As shown, it includes a first inductor L11, a signal circuit, a second inductor L12, a third inductor L13 and a sampling device. When the floating voltage sampling circuit is working, the first inductor is on the line on the floating voltage input side of the sampling device, and couples the AC component voltage Ve,ac of the floating voltage bus voltage Ve to the second inductor L12 and the third inductor L13 on the output line of the signal circuit, respectively, so that Ve,ac (common mode voltage) is offset between the signal end and the ground end of the signal circuit, thereby improving the anti-interference ability of the signal circuit. The signal circuit here can be a circuit that provides a driving signal for the floating voltage device, or a circuit that provides a control signal for the floating voltage device.

[0081] As a variation of this embodiment, in another floating voltage sampling circuit embodiment, the second inductor L12 and the third inductor L13 may also be arranged on the output line of the power supply circuit for supplying power to the signal circuit, or on the output line of the power supply circuit for supplying power to the signal circuit. Fig.18a On the basis of the embodiment shown, another group of two inductors coupled in the same direction as the first inductor are arranged on the output line of the power supply circuit for powering the signal circuit. The anti-interference principle is similar to the above embodiment.

[0082] On the basis of the above embodiment, the floating voltage sampling circuit may further include the above first capacitor or the second capacitor to improve the dynamic response effect of the floating voltage sampling circuit according to actual needs, and the connection method and principle are similar to the above embodiment. For example, the first inductor L11 is connected to the floating voltage input terminal of the sampling device through the first capacitor, or is grounded (GND1) through the first capacitor. For another example, the first inductor L11 is connected to the output terminal of the sampling device through the second capacitor.

[0083] The technical solution provided by the above embodiment uses the principle of coupling to couple the AC component of the moving point voltage to the affected circuit, which can reduce or even eliminate the jump voltage felt by the affected circuit, thereby effectively reducing the interference current and the common mode inductance originally connected in series to the interfered circuit. In addition, the technical solution provided by the above embodiment uses the principle of voltage cancellation to resist interference without causing loss. In addition, since the anti-interference circuit only couples the AC component, a DC blocking capacitor can be added, which has low control accuracy requirements for the circuit and high controllability. Further, the coupled inductor in the technical solution provided by the above embodiment contains an expandable voltage coupling winding, which can couple the moving point AC component voltage to the required target position according to actual needs, and the target position and the main power circuit are completely separated and do not share the current path. Furthermore, the coupling circuit in the anti-interference circuit can be combined with the output matching circuit (output network) according to the application scenario, which can reduce the circuit volume. In addition, in some scenarios, the coupling circuit can reuse components of existing circuits such as Buck output inductor, impedance matching network and DC blocking capacitor of RF power amplifier, without adding additional components.

[0084] It should be clear that the embodiments described in this application are only some embodiments, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application. The terms used in the embodiments of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. The singular forms of "a", "said" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0085] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

Claims

1. An anti-interference circuit for a high-frequency circuit, characterized in that: include: a first inductor, a second inductor, and a third inductor; The first inductor is in a same-direction coupling relationship with the second inductor and the third inductor, and the first inductor, the second inductor and the third inductor share a magnetic circuit; The coupled same-name end of the first inductor is used to connect the voltage moving point of the high-frequency circuit; the coupled same-name end of the second inductor and the third inductor is used to connect the device connected to the voltage moving point in the high-frequency circuit, and the coupled opposite-name end is used for the line to be interfered with, and the line to be interfered with is two lines in the high-frequency circuit connecting the devices; When the anti-interference circuit is working, the first inductor couples the AC component voltage of the voltage dynamic point to the second inductor and the third inductor respectively, so that the AC component voltage is offset between the two lines.

2. The circuit according to claim 1, characterized in that The AC component voltages of the first inductor coupled to the second inductor and the third inductor have the same amplitude and phase.

3. The circuit according to claim 1 or 2, characterized in that It also includes a first capacitor; the coupled opposite-name ends of the first inductor are grounded through the first capacitor, or the coupled same-name ends of the first inductor are connected to the voltage moving point through the first capacitor.

4. The circuit according to any one of claims 1 to 3, characterized in that: A second capacitor is also included, wherein the coupled opposite-name end of the first inductor is connected to one end of the second capacitor, and the other end of the second capacitor is used to connect to the device.

5. The circuit according to any one of claims 1 to 4, characterized in that: Also included is a seventh inductor and an eighth inductor; The first inductor is in a same-direction coupling relationship with the seventh inductor and the eighth inductor, and the seventh inductor and the eighth inductor share the magnetic circuit; The coupled like-name ends of the seventh inductor and the eighth inductor are used to connect the device connected to the voltage moving point in the high-frequency circuit, and the coupled opposite-name ends are used to connect another line to be interfered with, and the other line to be interfered with is another two lines in the high-frequency circuit connected to the device; When the anti-interference circuit is working, the first inductor couples the AC component voltage of the voltage dynamic point to the seventh inductor and the eighth inductor respectively, so that the AC component voltage offsets each other between the other two lines.

6. The circuit according to claim 5, characterized in that The number of turns of the coils of the seventh inductor and the eighth inductor is the same as the number of turns of the coil of the first inductor.

7. The circuit according to any one of claims 1 to 6, characterized in that: The first inductor, the second inductor and the third inductor have the same number of turns.

8. A high frequency power amplifier circuit, characterized in that: It includes a first auxiliary power supply, a first drive circuit, a first half-bridge circuit and a first anti-interference circuit; the first half-bridge circuit includes a first high-side switch tube and a first low-side switch tube, the control end of the first high-side switch tube is connected to the output end of the first drive circuit, the output end of the first high-side switch tube is connected to the input end of the first low-side switch tube, and the output end of the first low-side switch tube is grounded; The first anti-interference circuit includes a first inductor, a second inductor and a third inductor, the first inductor is in a same-direction coupling relationship with the second inductor and the third inductor, and the first inductor, the second inductor and the third inductor share a magnetic circuit; the positive electrode of the first auxiliary power supply is connected to the coupled opposite-name end of the second inductor, and the negative electrode is connected to the coupled opposite-name end of the third inductor; the coupled same-name end of the second inductor is connected to the power access end of the first drive circuit, the coupled same-name end of the third inductor is connected to the power grounding end of the first drive circuit, the output end of the first high-side switch tube and the coupled same-name end of the first inductor, and the coupled opposite-name end of the first inductor is grounded; When the high-frequency power amplifier circuit is working, the first inductor couples the AC component voltage of the first moving point voltage to the second inductor and the third inductor respectively, so that the AC component voltage of the first moving point voltage offsets each other between the positive and negative electrodes of the first auxiliary power supply; wherein the first moving point voltage is the voltage between the output end of the first high-side switch tube and the input end of the first low-side switch tube.

9. The circuit according to claim 8, characterized in that The first anti-interference circuit also includes a first capacitor, and the coupled opposite-name end of the first inductor is grounded through the first capacitor, or the coupled same-name end of the first inductor is connected to the output end of the first high-side switch tube through the first capacitor, and the coupled opposite-name end of the first inductor is grounded.

10. The circuit according to claim 8 or 9, characterized in that The first anti-interference circuit further includes a second capacitor, and the coupled opposite-name end of the first inductor is connected to the input end of the first high-side switch tube through the second capacitor.

11. The circuit according to any one of claims 8 to 10, characterized in that The first inductor, the second inductor and the third inductor have the same number of turns.

12. The circuit according to any one of claims 8 to 11, characterized in that It also includes a second auxiliary power supply, a second drive circuit, a second half-bridge circuit and a second anti-interference circuit; the second half-bridge circuit includes a second high-side switch tube and a second low-side switch tube, the control end of the second high-side switch tube is connected to the output end of the second drive circuit, the output end of the second high-side switch tube is connected to the input end of the second low-side switch tube, and the output end of the second low-side switch tube is grounded; the second anti-interference circuit includes a fourth inductor, a fifth inductor and a sixth inductor, the fourth inductor and the fifth inductor and the sixth inductor are all in the same direction coupling relationship, and the fourth inductor, the fifth inductor and the sixth inductor share a magnetic circuit; The positive electrode of the second auxiliary power supply is connected to the coupled opposite-name end of the fifth inductor, and the negative electrode is connected to the coupled opposite-name end of the sixth inductor; the coupled same-name end of the fifth inductor is connected to the power access end of the second drive circuit, and the coupled same-name end of the sixth inductor is connected to the power grounding end of the second drive circuit, the output end of the second high-side switch tube and the coupled same-name end of the fourth inductor; the coupled opposite-name end of the fourth inductor is grounded; When the high-frequency power amplifier circuit is working, the fourth inductor is used to couple the AC component voltage of the second moving-point voltage to the fifth inductor and the sixth inductor respectively, so that the voltage difference generated by the AC component voltage of the second moving-point voltage between the positive and negative branches of the second auxiliary power supply is zero; wherein the second moving-point voltage is the voltage between the output end of the second high-side switch tube and the input end of the second low-side switch tube.

13. The circuit according to claim 12, characterized in that The second auxiliary power source is the same as the first auxiliary power source.

14. The circuit according to claim 12 or 13, characterized in that The second anti-interference circuit also includes a third capacitor, and the coupled opposite-name end of the fourth inductor is grounded through the third capacitor, or the coupled same-name end of the fourth inductor is connected to the output end of the second high-side switch tube through the third capacitor, and the coupled opposite-name end of the fourth inductor is grounded.

15. The circuit according to claim 14, characterized in that The third capacitor and the first capacitor are the same capacitor.

16. The circuit according to any one of claims 12 to 15, characterized in that The second anti-interference circuit further includes a fourth capacitor, and a coupled opposite-name end of the fourth inductor is connected to an input end of the second high-side switch tube through the fourth capacitor.

17. The circuit according to claim 16, characterized in that The fourth capacitor and the second capacitor are the same capacitor.

18. The circuit according to any one of claims 12 to 17, characterized in that The fourth inductor, the fifth inductor and the sixth inductor have the same number of turns.

19. A high frequency circuit for converting alternating current into direct current, characterized in that: The invention comprises the circuit described in any one of claims 1 to 7, or comprises the circuit described in any one of claims 8 to 18.

20. A high frequency circuit for converting direct current into alternating current, characterized in that: The invention comprises the circuit described in any one of claims 1 to 7, or comprises the circuit described in any one of claims 8 to 18.

21. A high-frequency DC-to-DC circuit, characterized in that: The invention comprises the circuit as claimed in any one of claims 1 to 7.

22. A power supply, characterized in that: A circuit comprising any one of claims 1 to 21.

23. A high frequency circuit for converting direct current into alternating current, characterized in that: It includes a power amplifier circuit and an output matching circuit; the power amplifier circuit includes a first auxiliary power supply, a second inductor, a third inductor, a first drive circuit, and a first half-bridge circuit; the first half-bridge circuit includes a first high-side switch tube and a first low-side switch tube, and the output matching circuit includes a fifth capacitor and a first inductor; the first inductor is in a unidirectional coupling relationship with the second inductor and the third inductor, and the first inductor, the second inductor and the third inductor share a first magnetic circuit; The positive electrode of the first auxiliary power supply is connected to the coupled opposite-name end of the second inductor, the coupled same-name end of the second inductor is connected to the power input end of the first drive circuit, the negative electrode of the first auxiliary power supply is connected to the coupled opposite-name end of the third inductor, and the coupled same-name end of the third inductor is connected to the power ground end of the first drive circuit; the signal output end of the first drive circuit is connected to the control end of the first high-side switch tube, the power ground end of the first drive circuit is connected to the output end of the first high-side switch tube and the input end of the first low-side switch tube; the output end of the first high-side switch tube is connected to the coupled same-name end of the first inductor through the fifth capacitor; the coupled opposite-name end of the first inductor is grounded; When the high-frequency circuit is working, the first inductor couples the AC component voltage of the first moving-point voltage to the second inductor and the third inductor respectively, so that the AC component voltage of the first moving-point voltage offsets each other between the positive and negative branches of the first auxiliary power supply; wherein the first moving-point voltage is the voltage between the output end of the first high-side switch tube and the input end of the first low-side switch tube.

24. The circuit according to claim 23, characterized in that The power amplifier circuit further includes a second auxiliary power supply, a fifth inductor, a sixth inductor, a second driving circuit and a second half-bridge circuit, the second half-bridge circuit includes a second high-side switch tube and a second low-side switch tube, and the output matching circuit further includes a sixth capacitor and a fourth inductor; The fourth inductor is in a same-direction coupling relationship with the fifth inductor and the sixth inductor, and the fourth inductor, the fifth inductor and the sixth inductor share a second magnetic circuit; The positive electrode of the second auxiliary power supply is connected to the coupled opposite-name end of the fifth inductor, the coupled same-name end of the fifth inductor is connected to the power input end of the second drive circuit, the negative electrode of the second auxiliary power supply is connected to the coupled opposite-name end of the sixth inductor, and the coupled same-name end of the sixth inductor is connected to the power ground end of the second drive circuit; the signal output end of the second drive circuit is connected to the control end of the second high-side switch tube, and the power ground end is connected to the output end of the second high-side switch tube and the input end of the second low-side switch tube; the output end of the second high-side switch tube is connected to the coupled same-name end of the fourth inductor through the sixth capacitor; the coupled opposite-name end of the fourth inductor is connected to the coupled opposite-name end of the first inductor; When the high-frequency circuit is working, the fourth inductor couples the AC component voltage of the second moving-point voltage to the fifth inductor and the sixth inductor respectively, so that the AC component voltage of the second moving-point voltage offsets each other between the positive and negative branches of the second auxiliary power supply; wherein the second moving-point voltage is the voltage between the output end of the second high-side switch tube and the input end of the second low-side switch tube.

25. The circuit according to claim 24, characterized in that The second auxiliary power source is the same as the first auxiliary power source.

26. The circuit according to any one of claims 23 to 25, characterized in that Also includes a first signal isolation circuit, a seventh inductor, an eighth inductor and a first signal circuit; The seventh inductor and the eighth inductor are both in a unidirectional coupling relationship with the first inductor, and share the first magnetic circuit with the first inductor; the signal output end of the first signal isolation circuit is connected to the coupled opposite-name end of the seventh inductor, and the ground end of the first signal isolation circuit is connected to the coupled opposite-name end of the eighth inductor; the coupled same-name end of the seventh inductor is connected to the signal input end of the first signal circuit, and the coupled same-name end of the eighth inductor is connected to the ground end of the first signal circuit; the signal output end of the first signal circuit is connected to the signal input end of the first drive circuit, and the ground end of the first signal circuit is connected to the power ground end of the first drive circuit; When the high-frequency circuit is working, the first inductor is used to couple the AC component voltage of the first moving-point voltage to the seventh inductor and the eighth inductor respectively, so that the AC component voltage of the first moving-point voltage offsets each other between the signal input end, the signal output end and the ground end of the first signal circuit and the first signal isolation circuit.

27. A circuit according to any one of claims 24 to 26, characterized in that: Also includes a second signal isolation circuit, a ninth inductor, a tenth inductor and a second signal circuit; The ninth inductor and the tenth inductor are both in a same-direction coupling relationship with the fourth inductor, and share the second magnetic circuit with the fourth inductor; the signal output end of the second signal isolation circuit is connected to the coupled opposite-name end of the ninth inductor, and the ground end of the second signal isolation circuit is connected to the coupled opposite-name end of the tenth inductor; the coupled same-name end of the ninth inductor is connected to the signal input end of the second signal circuit, and the coupled same-name end of the tenth inductor is connected to the ground end of the second signal circuit; the signal output end of the second signal circuit is connected to the signal input end of the second drive circuit, and the ground end of the second signal circuit is connected to the power ground end of the second drive circuit; When the high-frequency circuit is working, the fourth inductor is used to couple the AC component voltage of the second moving-point voltage to the ninth inductor and the tenth inductor respectively, so that the AC component voltage of the second moving-point voltage offsets each other between the signal input end, the signal output end and the ground end of the second signal circuit and the second signal isolation circuit.

28. The circuit according to any one of claims 24 to 27, characterized in that The output matching circuit also includes a seventh capacitor, an eighth capacitor and a transformer; The coupled opposite-name ends of the first inductor and the fourth inductor are connected to the midpoint of the primary coil of the transformer, connected to the input end of the first high-side switch tube through the seventh capacitor, and grounded through the eighth capacitor.

29. A high frequency circuit for converting direct current into alternating current, characterized in that: It includes a first inductor, a signal isolation circuit, a seventh inductor, an eighth inductor, a signal circuit and a power amplifier circuit; the power amplifier circuit includes a drive circuit and a half-bridge circuit, and the half-bridge circuit includes a high-side switch tube and a low-side switch tube; the first inductor and the seventh inductor and the eighth inductor are all in a co-directional coupling relationship, and the first inductor, the seventh inductor and the eighth inductor share a magnetic circuit; The signal end of the signal isolation circuit is connected to the coupled opposite-name end of the seventh inductor, and the ground end is connected to the coupled opposite-name end of the eighth inductor; the coupled same-name end of the seventh inductor is connected to the signal input end of the signal circuit, and the coupled same-name end of the eighth inductor is connected to the ground end of the signal circuit; the signal output end of the signal circuit is connected to the signal input end of the drive circuit, and the ground end of the signal circuit is connected to the power ground end of the drive circuit; the signal output end of the drive circuit is connected to the control end of the high-side switch tube, and the power ground end of the drive circuit is connected to the output end of the high-side switch tube, the input end of the low-side switch tube and the coupled same-name end of the first inductor, and the coupled opposite-name end of the first inductor is grounded; When the high-frequency circuit is working, the first inductor couples the AC component voltage of the moving-point voltage to the seventh inductor and the eighth inductor respectively, so that the AC component voltage of the moving-point voltage offsets each other between the signal input terminal, the signal output terminal and the ground terminal of the signal circuit and the signal isolation circuit; wherein the moving-point voltage is the voltage between the output terminal of the high-side switch tube and the input terminal of the low-side switch tube.

30. The circuit according to claim 29, characterized in that It also includes a first capacitor, and the coupled opposite-name end of the first inductor is grounded through the first capacitor, or the coupled same-name end of the first inductor is connected to the output end of the high-side switch tube through the first capacitor.

31. The circuit according to claim 29 or 30, characterized in that It also includes a second capacitor, and the coupled opposite-name end of the first inductor is connected to the input end of the high-side switch tube through the second capacitor.

32. The circuit according to claim 30 or 31, characterized in that It also includes an output matching circuit, which includes the first capacitor and the first inductor, and the coupled same-name end of the first inductor is connected to the output end of the high-side switch tube through the first capacitor.

33. The circuit according to claim 32, characterized in that The output matching circuit also includes a seventh capacitor, an eighth capacitor and a transformer. The coupled opposite-name end of the first inductor is connected to the midpoint of the primary coil of the transformer, and is connected to the input end of the high-side switch tube through the seventh capacitor and is grounded through the eighth capacitor.

34. A DC step-down circuit, characterized in that: include: A first inductor, an auxiliary power supply, a second inductor, a third inductor, a driving circuit, a high-side switch tube, a low-side diode and a capacitor; The first inductor is in a same-direction coupling relationship with the second inductor and the third inductor, and the first inductor, the second inductor and the third inductor share a magnetic circuit; The positive electrode of the auxiliary power supply is connected to the coupled opposite-name end of the second inductor, and the negative electrode is connected to the coupled opposite-name end of the third inductor; the coupled same-name end of the second inductor is connected to the power access end of the drive circuit, and the coupled same-name end of the third inductor is connected to the power grounding end of the drive circuit and the output end of the high-side switch tube; the output end of the high-side switch tube is connected to the output end of the low-side diode and the coupled same-name end of the first inductor; the coupled opposite-name end of the first inductor is grounded through the capacitor; When the DC step-down circuit is working, the first inductor couples the AC component voltage of the moving point voltage to the second inductor and the third inductor respectively, so that the AC component voltage of the moving point voltage offsets each other between the positive and negative electrodes of the auxiliary power supply; wherein the moving point voltage is the voltage between the output end of the first high-side switch tube and the input end of the low-side diode.

35. A floating pressure sampling circuit, characterized in that: It includes a first inductor, a signal circuit, a second inductor, a third inductor and a sampling device; The first inductor is in a same-direction coupling relationship with the second inductor and the third inductor, and the first inductor, the second inductor and the third inductor share a magnetic circuit; The signal output terminal of the signal circuit is connected to the coupled opposite-name terminal of the second inductor, and the ground terminal is connected to the coupled opposite-name terminal of the third inductor; the coupled same-name terminal of the second inductor is connected to the signal input terminal of the sampling device, and the coupled same-name terminal of the third inductor is connected to the power ground terminal of the sampling device; the floating voltage input terminal of the sampling device is connected to the coupled same-name terminal of the first inductor, and the coupled opposite-name terminal of the first inductor is grounded; When the floating voltage sampling circuit is working, the first inductor couples the AC component voltage of the floating voltage input terminal voltage to the second inductor and the third inductor respectively, so that the AC component voltage is offset between the signal terminal and the ground terminal of the signal circuit.

36. The circuit according to claim 35, characterized in that It also includes a first capacitor; the coupled opposite-name end of the first inductor is grounded through the first capacitor, or the coupled same-name end of the first inductor is connected to the floating voltage input end of the sampling device through the first capacitor.

37. The circuit according to claim 35 or 36, characterized in that It also includes a second capacitor, and the coupled opposite-name end of the first inductor is connected to the output end of the sampling device through the second capacitor.

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