Power signal output circuit, ultrasonic power board and ultrasonic treatment device

Abstract

The utility model provides a kind of power signal output circuit, ultrasonic power board and ultrasonic treatment equipment, wherein, power signal output circuit is specifically used gallium nitride MOS tube to replace conventional silicon MOS tube, utilize its low on-resistance and superfast switching speed, directly energy loss (especially switching loss, this is particularly crucial under high frequency) is reduced to extremely low level.Heat output is greatly reduced, so that the temperature rise in the device is effectively controlled.Therefore, it can simplify or reduce the heat dissipation system, promote the miniaturization and quietness of equipment.Because the performance of single gallium nitride MOS tube is far more than conventional MOS tube, therefore, without again adopting the complex parallel structure of 6~8 tubes, only 2 tubes are needed to form half bridge to meet or even surpass original power output requirement.This directly simplifies circuit layout, reduces the number of components and cost.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a power signal output circuit, an ultrasonic power board, and an ultrasonic therapy device. Background Technology

[0002] Ultrasonic therapy devices, as common medical equipment, are widely used in physical therapy and rehabilitation. Their core function is to control the output of ultrasonic energy to treat specific areas. In existing technology, the energy output control of ultrasonic therapy devices typically employs an inverter circuit based on conventional MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) to regulate radio frequency energy. This circuit controls current and voltage through the switching action of the MOSFETs, thereby driving the treatment head to output ultrasonic signals.

[0003] However, conventional MOSFETs have significant technical drawbacks during operation. When the inverter circuit handles high voltage (e.g., ±100V) and high current, the MOSFET generates high on-resistance, leading to a large accumulation of heat and a rapid rise in temperature. This overheating not only reduces the efficiency and lifespan of the MOSFET but also raises the overall temperature of the host device, affecting its stability and safety. To mitigate the temperature rise problem, current technologies typically use multiple (e.g., 6-8) conventional MOSFETs connected in parallel to increase overcurrent capability, while requiring complex cooling systems (such as heat sinks or fans) to dissipate heat. This approach not only increases the complexity of circuit design and hardware costs but also results in bulky equipment with low energy conversion efficiency, limiting the performance optimization and miniaturization of ultrasonic therapy devices. Utility Model Content

[0004] This utility model provides a power signal output circuit, including: a digital frequency synthesizer, a driving circuit, a selection impedance matching circuit, and a half-bridge circuit composed of two gallium nitride MOS transistors; The drain of the first gallium nitride MOSFET is connected to a positive voltage; the source of the second gallium nitride MOSFET is connected to a negative voltage; the source of the first gallium nitride MOSFET and the drain of the second gallium nitride MOSFET are connected to the input terminal of the impedance matching circuit. The digital frequency synthesizer is connected to the controlled terminal of the driving circuit and is used to output a frequency signal to the driving circuit. The output terminal of the driving circuit is connected to the gate of the first gallium nitride MOS transistor and the gate of the second gallium nitride MOS transistor, respectively, and is used to output a first driving signal with the same frequency as the frequency signal to the gate of the first gallium nitride MOS transistor, and a second driving signal with the same frequency as the frequency signal to the gate of the second gallium nitride MOS transistor, so that the half-bridge circuit inverts and synthesizes the positive voltage and the negative voltage, and outputs the synthesized electrical signal to the selected impedance matching circuit. The impedance matching circuit has multiple impedance matching channels, which are used to adjust the frequency of the electrical signal output by the half-bridge circuit and output a power signal of a corresponding set frequency.

[0005] Optionally, the power signal output circuit further includes: Current detection circuit and two temperature sensors; The current detection circuit acquires the current values ​​flowing through the drain of the first gallium nitride MOS transistor and the source of the second gallium nitride MOS transistor, and outputs them to an external controller. The detection end of the first temperature sensor is in contact with the first gallium nitride MOS transistor to obtain the temperature value of the first gallium nitride MOS transistor and output it to an external controller. The detection end of the second temperature sensor is in contact with the second gallium nitride MOSFET to obtain the temperature value of the second gallium nitride MOSFET and output it to an external controller.

[0006] Optionally, the power signal output circuit further includes: a signal isolation transformer; The primary winding of the signal isolation transformer is connected to the output terminal of the driving circuit. The first end of the first secondary winding is connected to the gate of the first gallium nitride MOS transistor. The first end of the second secondary winding is connected to the gate of the second gallium nitride MOS transistor. The second end of the second secondary winding is connected to the source of the second gallium nitride MOS transistor.

[0007] Optionally, the power signal output circuit further includes: a signal isolation transformer; The first output terminal of the driving circuit is connected to the gate of the first gallium nitride MOS transistor, and the second output terminal is connected to the primary winding of the signal isolation transformer; the first end of the secondary winding of the signal isolation transformer is connected to the gate of the second gallium nitride MOS transistor, and the second end is connected to the source of the second gallium nitride MOS transistor.

[0008] Optionally, the power signal output circuit further includes: a DC blocking circuit; The DC blocking circuit is connected in series between the output terminal of the half-bridge circuit and the input terminal of the impedance matching circuit, and is used to isolate the DC component of the output electrical signal of the half-bridge circuit.

[0009] Optionally, the DC blocking circuit includes: a first capacitor; The first end of the first capacitor is connected to the output of the half-bridge circuit, and the second end is connected to the input of the impedance matching circuit.

[0010] Optionally, each impedance matching channel includes: a first switch, a second switch, and an LC oscillation filter circuit; The LC oscillation filter circuit is connected in series in the circuit between the first switch and the second switch; The controlled terminals of the first switch and the second switch are respectively connected to an external controller. The first switch and the second switch are used to turn on or off when receiving a conduction signal / cutoff signal. The LC oscillation filter circuit is used to adjust the frequency of the electrical signal output by the half-bridge circuit and output a power signal of a corresponding set frequency. The set frequency of the LC oscillation filter circuit in each impedance matching channel is different.

[0011] Optionally, the LC oscillation filter circuit includes: a first inductor, a second capacitor, and a third capacitor; The first terminal of the second capacitor is connected to the first terminal of the first switch and the first terminal of the first inductor, and the second terminal is grounded; the first terminal of the third capacitor is connected to the second terminal of the second switch and the second terminal of the first inductor, and the second terminal is grounded.

[0012] This utility model also proposes an ultrasonic power board, including an interface and the power signal output circuit; The interface is electrically connected to the output terminal of the impedance matching circuit; the interface is used to connect to the ultrasonic handpiece cable or the ultrasonic treatment head.

[0013] This utility model also proposes an ultrasound therapy device, including: a controller, a power module, and a power signal output circuit; The controller is connected to the digital frequency synthesizer and the impedance matching circuit respectively, outputs control commands to the digital frequency synthesizer, and / or outputs channel selection commands to the impedance matching circuit. The power module is used to provide the positive voltage and the negative voltage.

[0014] This invention proposes a power signal output circuit, an ultrasonic power board, and an ultrasonic therapy device. Specifically, the power signal output circuit uses gallium nitride (GaN) MOSFETs instead of conventional silicon MOSFETs. Utilizing GaN's low on-resistance and ultra-fast switching speed, energy loss (especially switching loss, which is critical at high frequencies) is directly reduced to an extremely low level. The significant reduction in heat generation effectively controls the internal temperature rise of the device. Therefore, the heat dissipation system can be simplified or reduced, promoting miniaturization and quieter operation of the device. Since the performance of a single GaN MOSFET far exceeds that of a conventional MOSFET, there is no need for a complex parallel structure of 6-8 MOSFETs; only two MOSFETs forming a half-bridge are needed to meet or even exceed the original power output requirements. This directly simplifies the circuit layout and reduces the number of components and cost. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the first structure of an embodiment of the power signal output circuit of this utility model; Figure 2 This is a second structural schematic diagram of an embodiment of the power signal output circuit of this utility model; Figure 3 This is a schematic diagram of the first structure of a second embodiment of the power signal output circuit of this utility model; Figure 4 This is a second structural schematic diagram of an embodiment of the power signal output circuit of this utility model; Figure 5 This is a schematic diagram of the third structure of an embodiment of the power signal output circuit of this utility model; Figure 6 This is a schematic diagram of the fourth structure of an embodiment of the power signal output circuit of this utility model; Figure 7 This is a fifth structural schematic diagram of an embodiment of the power signal output circuit of this utility model; Figure 8 This is a schematic diagram of the first structure of three embodiments of the power signal output circuit of this utility model; Figure 9 This is a schematic diagram of the second structure of the power signal output circuit of this utility model in three embodiments; Figure 10 This is a schematic diagram of the third structure of the three embodiments of the power signal output circuit of this utility model.

[0017] Explanation of icon numbers:

[0018] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0021] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0023] This utility model provides a power signal output circuit, such as Figure 1 As shown, in the first embodiment, the power signal output circuit includes: a digital frequency synthesizer 10, a driving circuit 20, a selection impedance matching circuit 30, and a half-bridge circuit composed of two gallium nitride MOS transistors; The drain of the first gallium nitride MOSFET is connected to a positive voltage; the source of the second gallium nitride MOSFET is connected to a negative voltage; the source of the first gallium nitride MOSFET and the drain of the second gallium nitride MOSFET are connected to the input terminal of the impedance matching circuit 30. The digital frequency synthesizer 10 is connected to the controlled terminal of the drive circuit 20 and is used to output frequency signals to the drive circuit 20. The output terminal of the driving circuit 20 is connected to the gate of the first gallium nitride MOS transistor and the gate of the second gallium nitride MOS transistor respectively. It is used to output a first driving signal with the same frequency as the frequency signal to the gate of the first gallium nitride MOS transistor, and a second driving signal with the same frequency as the frequency signal to the gate of the second gallium nitride MOS transistor, so that the half-bridge circuit can invert the positive voltage and the negative voltage and synthesize them, and output the synthesized electrical signal to the impedance matching circuit 30. The impedance matching circuit 30 has multiple impedance matching channels, which are used to adjust the frequency of the electrical signal output by the half-bridge circuit and output a power signal of the corresponding set frequency.

[0024] It should be explained that the digital frequency synthesizer 10 is used to generate precise and stable high-frequency AC signals. It receives instructions from an external controller (such as an MCU) to generate drive signals of specific frequencies (e.g., 2MHz, 3MHz, or 6MHz); it provides high-precision and programmable frequency control, enabling the ultrasound therapy device to flexibly output ultrasound waves of different frequencies according to different treatment needs, enhancing the device's versatility and therapeutic effect. The drive circuit 20 receives the weak frequency signal generated by the digital frequency synthesizer 10, amplifies the power, and shapes the waveform to generate a drive signal with sufficient voltage and current capabilities, reliably controlling the rapid switching on and off of the subsequent gallium nitride MOSFET; ensuring efficient and lossless conversion between the control signal and the power switch.

[0025] In this half-bridge circuit, the MOSFET is a gallium nitride (GaN) MOSFET. Gallium nitride (GaN) material possesses extremely high electron mobility and a wide bandgap, resulting in significantly lower on-resistance (Rds(on)) and switching losses (especially at high frequencies) compared to traditional silicon-based MOSFETs. As mentioned in the background, conventional MOSFETs generate significant heat due to high losses. This solution uses GaN MOSFETs, fundamentally reducing heat generation. This allows only 1-2 GaN MOSFETs to replace 6-8 conventional MOSFETs, greatly simplifying the circuit. Furthermore, GaN devices can handle switching operations at frequencies up to 7MHz or even higher, while also withstanding high voltage and current, providing a high-performance power output foundation for ultrasound therapy equipment. Due to their low heat generation, GaN MOSFETs significantly reduce the requirements for the heat dissipation system, contributing to equipment miniaturization, weight reduction, and cost reduction.

[0026] In addition, the drain of the first gallium nitride MOSFET is connected to a positive voltage; the source of the second gallium nitride MOSFET is connected to a negative voltage; the source of the first gallium nitride MOSFET and the drain of the second gallium nitride MOSFET are connected to the input terminal of the impedance matching circuit 30. The driving circuit 20 outputs a first driving signal to the gate of the first gallium nitride MOSFET and outputs a signal to the gate of the second gallium nitride MOSFET; the driving circuit 20 can generate a square wave by alternately turning on the two gallium nitride MOSFETs, using positive and negative voltages. For example: during the first duration, the first gallium nitride MOSFET is turned on (the second gallium nitride MOSFET is turned off), and the half-bridge circuit outputs a positive voltage; during the second duration, the second gallium nitride MOSFET is turned on (the first gallium nitride MOSFET is turned off), and the half-bridge circuit outputs a negative voltage; the positive voltage during the first duration and the negative voltage during the second duration combine to form an AC signal, and the first duration and the second duration constitute the AC signal period. The half-bridge circuit outputs the combined square wave signal to the impedance matching circuit. In addition, the first duration and the second duration depend on the frequency value of the frequency signal output by the digital frequency synthesizer 10. The first duration is equal to the second duration, which can be determined by T, where T is the first duration or the second duration, and f is the frequency value of the frequency signal.

[0027] The impedance matching circuit 30 has multiple impedance matching channels (e.g., corresponding to 1M, 2M, and 3M). It receives the high-frequency AC signal synthesized by the half-bridge circuit and performs impedance transformation and filtering on signals of different frequencies through an internal switchable LC network. This ensures that ultrasound energy is efficiently transmitted from the circuit to the treatment head (transducer) while filtering out unnecessary harmonics. The selection frequency (set frequency) of each impedance matching channel can be set. The impedance matching channel adjusts the electrical signal output by the half-bridge circuit, outputting a power signal at the corresponding set frequency. Each impedance matching channel includes a resonant circuit; by setting the resonant frequency, the corresponding set frequency power signal is output.

[0028] It is easy to understand that in the therapeutic device, the output terminal of the power signal output circuit (i.e. the output terminal of the impedance matching circuit 30) can be connected to the treatment head. The type of treatment head is closely related to the type of therapeutic device. For example, an ultrasonic treatment head corresponds to an ultrasonic therapeutic device, and a radio frequency treatment head corresponds to a radio frequency medical device.

[0029] A single treatment device may be equipped with multiple treatment heads of different frequencies (e.g., 1MHz, 2MHz, 7MHz heads), or a single treatment head may integrate multiple transducers with different resonant frequencies. The circuit of this invention ensures that for any connected treatment head, the circuit can output its corresponding optimal frequency signal and achieve optimal impedance matching by switching different impedance matching channels. Furthermore, it is easy to understand that once a treatment head is selected, the controller can control the digital frequency synthesizer 10 to output a frequency signal with the same resonant frequency as that treatment head.

[0030] This invention proposes a power signal output circuit that specifically replaces conventional silicon MOSFETs with gallium nitride (GaN) MOSFETs. Utilizing GaN's low on-resistance and ultra-fast switching speed, energy loss (especially switching loss, which is critical at high frequencies) is directly reduced to an extremely low level. The significant reduction in heat generation effectively controls the internal temperature rise of the device. Therefore, the heat dissipation system can be simplified or reduced, promoting miniaturization and quieter operation. Since the performance of a single GaN MOSFET far exceeds that of a conventional MOSFET, there is no need for a complex parallel structure of 6-8 MOSFETs; only two MOSFETs forming a half-bridge are needed to meet or even exceed the original power output requirements. This directly simplifies the circuit layout and reduces the number of components and cost.

[0031] In one example, such as Figure 2 As shown, the power signal output circuit also includes: Current detection circuit 40 and two temperature sensors; The current detection circuit 40 acquires the current values ​​flowing through the drain of the first gallium nitride MOSFET and the source of the second gallium nitride MOSFET, and outputs them to the external controller. The detection end of the first temperature sensor is in contact with the first gallium nitride MOSFET to obtain the temperature value of the first gallium nitride MOSFET and output it to an external controller. The detection end of the second temperature sensor is in contact with the second gallium nitride MOSFET to obtain the temperature value of the second gallium nitride MOSFET and output it to an external controller.

[0032] It is easy to understand that the current detection circuit 40 can include two current detection units (such as a dedicated current detection chip or a combination of sampling resistor and operational amplifier), which are connected in series or coupled to the drain (positive voltage path) of the first gallium nitride MOSFET and the source (negative voltage path) of the second gallium nitride MOSFET, respectively. It monitors the total current flowing through the two gallium nitride MOSFETs in real time and accurately, and converts this current data into readable signals (such as voltage signals or digital signals) and outputs them to an external controller (such as an MCU). The detection terminals of two temperature sensors (preferably thermistors due to their small size and fast response) are physically in contact with the casings or heat sinks of the first and second gallium nitride MOSFETs, respectively. They directly measure the temperature of the power transistors themselves and transmit the temperature values ​​to an external controller.

[0033] This example manages residual heat and abnormal conditions through current and temperature monitoring. Abnormal current is often a precursor to a surge in heat generation, while the temperature sensor provides the final detection of the heating result. The combination of these two technologies enables end-to-end thermal monitoring. An external controller can dynamically adjust the output of the digital frequency synthesizer 10 or the parameters of the drive circuit 20 based on the monitored current and temperature data, ensuring the system always operates in an optimal and safest state.

[0034] Even though gallium nitride (GaN) devices are inherently highly reliable, the complexity and uncertainty of the load (treatment head and human tissue) still exist. This invention achieves precise "point-to-point" temperature monitoring by equipping each GaN MOSFET with a direct-contact temperature sensor. Overheating of any single MOSFET can be detected and addressed immediately, making protection measures more timely and effective.

[0035] In the second embodiment of this invention, in the half-bridge circuit, the source potential of the upper transistor (first gallium nitride MOS transistor) switches rapidly between 0V and a positive voltage (e.g., +200V), and the reference ground for its gate drive signal is 0V. The source of the lower transistor (second gallium nitride MOS transistor) is connected to a negative voltage (e.g., -200V), and the reference ground for its gate drive signal must be a negative voltage (e.g., -200V), not the system's 0V ground. If the negative voltage value is small (e.g., -200V), if the lower transistor is directly driven by the drive circuit 20, the drive circuit 20 needs to have the capability to output a voltage near -200V. If it does not have this capability, the PN junction between the gate and source of the second gallium nitride MOS transistor will be damaged, leading to the breakage of the second gallium nitride MOS transistor. The above example only uses ±200V and does not limit the actual positive and negative voltage amplitudes used.

[0036] To solve this problem, in one example, such as Figure 3 As shown, the power signal output circuit also includes: a signal isolation transformer; The primary winding of the signal isolation transformer is connected to the output terminal of the drive circuit 20. The first end of the first secondary winding is connected to the gate of the first gallium nitride MOS transistor, and the second end is connected to the source of the first gallium nitride MOS transistor. The first end of the second secondary winding is connected to the gate of the second gallium nitride MOS transistor, and the second end of the second secondary winding is connected to the source of the second gallium nitride MOS transistor.

[0037] It should be noted that in this example, the signal isolation transformer has two secondary coils, one connected to the first gallium nitride MOSFET and the other to the second gallium nitride MOSFET. The driving circuit 20 outputs a driving signal to the primary coil to control the first and second gallium nitride MOSFETs. The frequency of the driving signal is the same as the frequency signal. It is particularly important to emphasize that one end of the second secondary coil is connected to the gate of the second gallium nitride MOSFET, and the other end is connected to the source of the second gallium nitride MOSFET. After the driving circuit 20 outputs the driving signal, the voltage difference between the gate and source voltages of the second gallium nitride MOSFET depends on the induced voltage value on the second secondary coil, thereby enabling the normal driving of the second gallium nitride MOSFET to turn on or off. Therefore, this example can solve the problem of small negative voltages, high requirements for the driving circuit 20, or damage to the second gallium nitride MOSFET.

[0038] Furthermore, this invention does not limit the types of the first and second gallium nitride MOSFETs, nor the ports of the first and second secondary coils that are opposite in name. To achieve alternating conduction of the first and second gallium nitride MOSFETs, the following configuration is proposed: 1. For example Figure 4 As shown, both the first and second gallium nitride MOSFETs are NMOS or PMOS transistors, and the first terminals of the first and second secondary windings are opposite terminals. By utilizing the opposite voltage polarities at these opposite terminals, it is determined that the first and second gallium nitride MOSFETs do not conduct simultaneously. That is, the signal isolation transformer can naturally generate two drive signals with opposite phases and mutual isolation, enabling the first and second gallium nitride MOSFETs to conduct alternately.

[0039] 2. For example Figure 5 As shown, the first gallium nitride MOS transistor and the second gallium nitride MOS transistor are NMOS transistors and PMOS transistors, respectively. The first terminal of the first secondary coil (the gate of the first gallium nitride MOS transistor) and the first terminal of the second secondary coil (the gate of the second gallium nitride MOS transistor) are the same terminal. Since the first gallium nitride MOS transistor and the second gallium nitride MOS transistor have different conduction conditions, the first gallium nitride MOS transistor and the second gallium nitride MOS transistor can be alternately turned on by controlling the drive signal.

[0040] It should be noted that in the half-bridge circuit, the source of the first gallium nitride MOSFET is connected to the input terminal of the impedance matching circuit 30; however, the source of the second gallium nitride MOSFET is connected to a negative voltage; and the conduction of the MOSFET depends on the voltage difference between its gate and source. Therefore, in the half-bridge circuit, it is only necessary to consider whether the second gallium nitride MOSFET will be damaged due to the negative voltage. Additionally, the coil is relatively large, which is not conducive to miniaturization.

[0041] In another example, the power signal output circuit also includes a signal isolation transformer; The first output terminal of the driving circuit 20 is connected to the gate of the first gallium nitride MOS transistor, and the second output terminal is connected to the primary winding of the signal isolation transformer; the first end of the secondary winding of the signal isolation transformer is connected to the gate of the second gallium nitride MOS transistor, and the second end is connected to the source of the second gallium nitride MOS transistor.

[0042] In this example, the drive circuit 20 has two output terminals. One output terminal is directly connected to the gate of the first gallium nitride MOSFET, and the other output terminal is isolated and connected to the gate of the second gallium nitride MOSFET through a signal isolation transformer. Reducing one secondary winding reduces the size and facilitates miniaturization.

[0043] The function of the secondary coil is the same as that of the second secondary coil mentioned above, and will not be repeated here.

[0044] Furthermore, it should be noted that whether the first gallium nitride MOSFET and the second gallium nitride MOSFET are of the same type (this should be understood as whether their conduction conditions are the same, for example, both are NMOS / PMOS transistors, or they are different) depends on the output timing of the output signals at the first and second output terminals of the driver circuit 20, as well as the winding method of the signal isolation transformer. There are several possible forms: 1. For example Figure 6 As shown, when the output signals of the first output terminal and the second output terminal are the same (for example, both are greater than the turn-on voltage of the MOS transistor), and when the first end of the secondary coil and the end of the primary coil connected to the drive circuit 20 are of the same name, the first gallium nitride MOS transistor and the second gallium nitride MOS transistor are of different types.

[0045] 2. For example Figure 7 As shown, when the output signal of the first output terminal and the output signal of the second output terminal are the same (for example, both are greater than the conduction voltage of the MOS transistor), and when the first end of the secondary coil and the end of the primary coil connected to the drive circuit 20 are opposite terminals, the first gallium nitride MOS transistor and the second gallium nitride MOS transistor are of the same type.

[0046] 3. When the output signals of the first output terminal and the second output terminal are different, and the first end of the secondary coil and the end of the primary coil connected to the driving circuit 20 are of the same name, the first gallium nitride MOS transistor and the second gallium nitride MOS transistor are of the same type.

[0047] 4. When the output signals of the first output terminal and the second output terminal are different, and the first end of the secondary coil and the end of the primary coil connected to the driving circuit 20 are opposite terminals, the first gallium nitride MOS transistor and the second gallium nitride MOS transistor are of the same type.

[0048] Furthermore, when the output signal of the first output terminal and the output signal of the second output terminal are the same, the first output terminal and the second output terminal can be combined into one output terminal.

[0049] In the third embodiment of this utility model, the power signal output circuit further includes: a DC blocking circuit; A DC blocking circuit is connected in series between the output terminal of the half-bridge circuit and the input terminal of the impedance matching circuit 30 to isolate the DC component of the output electrical signal of the half-bridge circuit.

[0050] It should be noted that the DC blocking circuit is connected in series between the output of the half-bridge circuit and the input of the impedance matching circuit 30. Its core function is to isolate (block) the DC component in the electrical signal output by the half-bridge circuit, while allowing the AC component (i.e., the useful high-frequency ultrasound signal) to pass through unimpeded. Combining the DC blocking circuit (first capacitor C1) with the half-bridge circuit and the impedance matching circuit 30, the half-bridge circuit is responsible for efficiently generating a high-voltage, high-frequency AC signal, but this raw signal may contain harmful DC components. The DC blocking capacitor acts like a "safety valve" or "purifier," filtering out DC "impurities" before the signal enters the finely tuned impedance matching network and the preceding load, protecting the subsequent expensive circuitry and treatment head.

[0051] like Figure 8 As shown, the DC blocking circuit includes: a first capacitor C1; The first terminal of the first capacitor C1 is connected to the output terminal of the half-bridge circuit, and the second terminal is connected to the input terminal of the impedance matching circuit 30.

[0052] It is easy to understand that, compared to other complex active DC blocking solutions, a single capacitor has significant advantages in terms of cost and board space.

[0053] In one example, such as Figure 9 As shown, each impedance matching channel includes: a first switch, a second switch, and an LC oscillation filter circuit; An LC oscillation filter circuit is connected in series in the circuit between the first switch and the second switch; The controlled terminals of the first switch and the second switch are respectively connected to an external controller. The first switch and the second switch are used to turn on or off when receiving a conduction signal / cutoff signal. The LC oscillation filter circuit is used to adjust the frequency of the electrical signal output by the half-bridge circuit and output a power signal of the corresponding set frequency. The set frequency of the LC oscillation filter circuit in each impedance matching channel is different.

[0054] In this example, First and Second Switches: The first and second switches (preferably relays due to their high power carrying capacity and good isolation) are connected in series at the input and output terminals of the impedance matching channel, respectively. Their controlled terminals receive channel selection commands from an external controller. Through on or off actions, they physically connect or disconnect the corresponding LC oscillation filter circuit to or from the main power signal path, thereby achieving hard switching of the frequency channel. The LC oscillation filter circuit is connected in series between the two switches. Utilizing the resonant characteristics of inductance and capacitance, it presents low impedance to signals near its resonant frequency, allowing them to pass efficiently; while presenting high impedance to signals of other frequencies, causing significant attenuation. By setting different L and C parameters for each channel, it resonates at a specific frequency (e.g., 1MHz, 2MHz, 3MHz, 4MHz), meaning the set frequency of the LC oscillation filter circuit in each impedance matching channel is different. The set frequency is determined by the R&D personnel. The LC circuit of each channel acts as a bandpass filter, ensuring that only the power signal of the target frequency can be efficiently output, while filtering out high-order harmonics and other noise generated by the half-bridge inverter.

[0055] like Figure 10 As shown, the LC oscillation filter circuit can be specifically a π-type structure, including: a first inductor L1, a second capacitor C2, and a third capacitor C3; The first terminal of the second capacitor C2 is connected to the first terminal of the first switch and the first terminal of the first inductor L1, and the second terminal is grounded; the first terminal of the third capacitor C3 is connected to the second terminal of the second switch and the first inductor L1, and the second terminal is grounded.

[0056] The first inductor L1 is mainly used for tuning and impedance transformation. The second capacitor C2 and the third capacitor C3 are connected in parallel between the signal path and ground, forming a "π"-shaped structure. Together with the first inductor L1, they determine the resonant frequency of the circuit and provide an effective path for non-resonant frequency signals to be discharged to ground, enhancing the filtering effect. The π-shaped structure provides second-order filtering, with a steeper out-of-band attenuation characteristic than a simple single LC resonant circuit, and can more effectively suppress spurious signals and higher harmonics.

[0057] This utility model also proposes an ultrasonic power board, including: an interface and a power signal output circuit; The interface is electrically connected to the output of impedance matching circuit 30; the interface is used to connect to the ultrasonic handpiece cable or ultrasonic treatment head.

[0058] It is easy to understand that, The power signal output circuit integrates all functions from signal generation (digital frequency synthesizer 10), driving and inversion (drive circuit 20, isolation transformer, gallium nitride half-bridge) to signal processing and matching (DC blocking circuit, impedance matching circuit 30) and safety monitoring (current and temperature detection). Its function is to convert the low-voltage DC power from the power supply module (after internal conversion) and the instructions from the controller into high-frequency, high-voltage, high-power ultrasound signals that can be used by the treatment head.

[0059] This interface is the physical and electrical connection point between the ultrasound power board and the outside world. It is directly electrically connected to the output of the impedance matching circuit 30, and is responsible for transmitting the precisely tuned final power signal losslessly through the ultrasound handpiece cable to the ultrasound treatment head (transducer) at the end.

[0060] The specific structure of the power signal output circuit is as described in the above embodiments. Since this ultrasonic power board adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0061] This utility model also proposes an ultrasound therapy device, including: a controller, a power module, and a power signal output circuit; The controller is connected to the digital frequency synthesizer 10 and the impedance matching circuit 30 respectively, outputs control commands to the digital frequency synthesizer 10, and / or outputs channel selection commands to the impedance matching circuit 30. The power module is used to provide both positive and negative voltages.

[0062] The controller may include an MCU, FPGA, or SOC. The power module is used to convert the input AC or battery power into a stable and clean positive voltage (e.g., +200V) and negative voltage (e.g., -200V) required by the power signal output circuit.

[0063] The specific structure of the power signal output circuit is as described in the above embodiments. Since this ultrasound therapy device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0064] The above are merely optional embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made under the concept of this utility model using the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A power signal output circuit, characterized in that, include: A half-bridge circuit consisting of a digital frequency synthesizer, a driver circuit, a selection impedance matching circuit, and two gallium nitride MOSFETs; The drain of the first gallium nitride MOSFET is connected to a positive voltage; The source of the second gallium nitride MOSFET is connected to a negative voltage; the source of the first gallium nitride MOSFET and the drain of the second gallium nitride MOSFET are connected to the input terminal of the impedance matching circuit. The digital frequency synthesizer is connected to the controlled terminal of the driving circuit and is used to output a frequency signal to the driving circuit. The output terminal of the driving circuit is connected to the gate of the first gallium nitride MOS transistor and the gate of the second gallium nitride MOS transistor, respectively, and is used to output a first driving signal with the same frequency as the frequency signal to the gate of the first gallium nitride MOS transistor, and a second driving signal with the same frequency as the frequency signal to the gate of the second gallium nitride MOS transistor, so that the half-bridge circuit inverts and synthesizes the positive voltage and the negative voltage, and outputs the synthesized electrical signal to the selected impedance matching circuit. The impedance matching circuit has multiple impedance matching channels, which are used to adjust the frequency of the electrical signal output by the half-bridge circuit and output a power signal of a corresponding set frequency.

2. The power signal output circuit as described in claim 1, characterized in that, The power signal output circuit also includes: Current detection circuit and two temperature sensors; The current detection circuit acquires the current values ​​flowing through the drain of the first gallium nitride MOS transistor and the source of the second gallium nitride MOS transistor, and outputs them to an external controller. The detection end of the first temperature sensor is in contact with the first gallium nitride MOS transistor to obtain the temperature value of the first gallium nitride MOS transistor and output it to an external controller. The detection end of the second temperature sensor is in contact with the second gallium nitride MOSFET to obtain the temperature value of the second gallium nitride MOSFET and output it to an external controller.

3. The power signal output circuit as described in claim 1, characterized in that, The power signal output circuit also includes: a signal isolation transformer; The primary winding of the signal isolation transformer is connected to the output terminal of the driving circuit. The first end of the first secondary winding is connected to the gate of the first gallium nitride MOS transistor, and the second end is connected to the source of the first gallium nitride MOS transistor. The first end of the second secondary winding is connected to the gate of the second gallium nitride MOS transistor, and the second end of the second secondary winding is connected to the source of the second gallium nitride MOS transistor.

4. The power signal output circuit as described in claim 1, characterized in that, The power signal output circuit also includes: a signal isolation transformer; The first output terminal of the driving circuit is connected to the gate of the first gallium nitride MOS transistor, and the second output terminal is connected to the primary winding of the signal isolation transformer; the first end of the secondary winding of the signal isolation transformer is connected to the gate of the second gallium nitride MOS transistor, and the second end is connected to the source of the second gallium nitride MOS transistor.

5. The power signal output circuit as described in any one of claims 1 to 4, characterized in that, The power signal output circuit further includes: a DC blocking circuit; The DC blocking circuit is connected in series between the output terminal of the half-bridge circuit and the input terminal of the impedance matching circuit, and is used to isolate the DC component of the output electrical signal of the half-bridge circuit.

6. The power signal output circuit as described in claim 5, characterized in that, The DC blocking circuit includes: a first capacitor; The first end of the first capacitor is connected to the output of the half-bridge circuit, and the second end is connected to the input of the impedance matching circuit.

7. The power signal output circuit as described in any one of claims 1 to 4, characterized in that, Each impedance matching channel includes: a first switch, a second switch, and an LC oscillation filter circuit; The LC oscillation filter circuit is connected in series in the circuit between the first switch and the second switch; The controlled terminals of the first switch and the second switch are respectively connected to an external controller. The first switch and the second switch are used to turn on or off when receiving a conduction signal / cutoff signal. The LC oscillation filter circuit is used to adjust the frequency of the electrical signal output by the half-bridge circuit and output a power signal of a corresponding set frequency. The set frequency of the LC oscillation filter circuit in each impedance matching channel is different.

8. The power signal output circuit as described in claim 7, characterized in that, The LC oscillation filter circuit includes: a first inductor, a second capacitor, and a third capacitor; The first terminal of the second capacitor is connected to the first terminal of the first switch and the first terminal of the first inductor, and the second terminal is grounded; the first terminal of the third capacitor is connected to the second terminal of the second switch and the second terminal of the first inductor, and the second terminal is grounded.

9. An ultrasonic power board, characterized in that, Includes an interface and a power signal output circuit as described in any one of claims 1 to 8; The interface is electrically connected to the output terminal of the impedance matching circuit; the interface is used to connect to the ultrasonic handpiece cable or the ultrasonic treatment head.

10. An ultrasound therapy device, characterized in that, include: The controller, the power module, and the power signal output circuit as described in any one of claims 1 to 8; The controller is connected to the digital frequency synthesizer and the impedance matching circuit respectively, outputs control commands to the digital frequency synthesizer, and / or outputs channel selection commands to the impedance matching circuit. The power module is used to provide the positive voltage and the negative voltage.

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