Sine wave generating circuit and electronic device

Abstract

The present application discloses a sine wave generating circuit and an electronic device. The sine wave generating circuit comprises a first signal conversion module, a class-D power amplifier, a second signal conversion module and a voltage control module. The first signal conversion module converts a square wave signal into a first sine wave signal with adjustable amplitude. The class-D power amplifier performs power amplification and modulation on the first sine wave signal and then outputs a high-frequency carrier pulse width modulation signal. The second signal conversion module demodulates the high-frequency carrier pulse width modulation signal, boosts the demodulated signal, and then outputs a second sine wave signal. The voltage control module outputs an adjustment signal to the first signal conversion module on the basis of a control signal and the second sine wave signal to adjust the amplitude of the first sine wave signal until the voltage of the control signal and the voltage of the second sine wave signal satisfy a preset relationship. By means of the above mode, corresponding sine wave signals can be output according to user requirements, and high conversion efficiency and high reliability are achieved.

Description

Sine wave generating circuit and electronic equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on February 1, 2024, with application number 202410158077.5 and application name “Sine Wave Generating Circuit and Electronic Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of power electronics technology, and in particular to a sine wave generating circuit and electronic equipment. Background Art

[0004] A high-voltage sine wave is a voltage waveform characterized by periodic variations and a sinusoidal curve. In power systems, high-voltage sine waves are commonly used for transmission and distribution of electricity to industrial, commercial, and residential applications. Currently, generating high-voltage sine waves requires specialized circuits to meet the needs of various applications.

[0005] However, the conversion efficiency of the circuits currently used to generate high-voltage sine waves is low, which may cause severe heating or even damage to the devices and has low reliability.

[0006] Application Contents

[0007] The embodiments of the present application aim to provide a sine wave generating circuit and an electronic device that can output corresponding sine wave signals according to user needs, and have high conversion efficiency and high reliability.

[0008] To achieve the above-mentioned purpose, in a first aspect, the present application provides a sine wave generating circuit, comprising: a first signal conversion module, the first signal conversion module inputting a square wave signal, the first signal conversion module being used to convert the square wave signal into a first sine wave signal with adjustable amplitude; a class D power amplifier, the class D power amplifier being connected to the first signal conversion module, the class D power amplifier inputting the first sine wave signal, the class D power amplifier being used to amplify the power of the first sine wave signal and modulate it to output a high-frequency carrier pulse width modulation signal; a second signal conversion module, the second signal conversion module being connected to the class D power amplifier, the second signal conversion module being used to amplify the power of the first sine wave signal and modulate it to output a high-frequency carrier pulse width modulation signal; The block inputs the high-frequency carrier pulse width modulation signal, and the second signal conversion module is used to demodulate and boost the high-frequency carrier pulse width modulation signal and then output a second sinusoidal wave signal; a voltage control module, the voltage control module is connected between the second signal conversion module and the first signal conversion module, the voltage control module inputs the second sinusoidal wave signal and the control signal, and the voltage control module is used to output an adjustment signal to the first signal conversion module based on the control signal and the second sinusoidal wave signal to adjust the amplitude of the first sinusoidal wave signal until the voltage of the control signal and the second sinusoidal wave signal meet a preset relationship.

[0009] In one or more embodiments, the first signal conversion module includes a signal conversion unit and a signal amplification unit; the signal conversion unit inputs the square wave signal, and the signal conversion unit is used to convert the square wave signal into a third sinusoidal wave signal; the signal amplification unit is connected to the signal conversion unit, the signal amplification unit inputs the third sinusoidal wave signal, and the signal conversion unit is used to output the first sinusoidal wave signal based on the third sinusoidal wave signal, wherein the amplitude of the first sinusoidal wave signal is determined by the amplitude of the third sinusoidal wave signal and the gain of the signal amplification unit.

[0010] In one or more embodiments, when the Class D power amplifier is a single-ended output, the second signal conversion module includes a first filtering unit and a first boosting unit; the first filtering unit is connected between the Class D power amplifier and the first boosting unit, and the first filtering unit is used to filter the high-frequency carrier pulse width modulation signal to demodulate the high-frequency carrier pulse width modulation signal; the first boosting unit is used to boost the demodulated signal of the high-frequency carrier pulse width modulation signal and output the second sinusoidal wave signal.

[0011] In one or more embodiments, the first filtering unit includes a first inductor, a first capacitor and a second capacitor, and the first boost unit includes a first transformer; the first end of the first inductor is connected to the Class D power amplifier, the second end of the first inductor is respectively connected to the first end of the first capacitor and the first end of the second capacitor, the second end of the first capacitor is connected to the first end of the primary winding of the first transformer, the second end of the second capacitor, the second end of the primary winding of the first transformer and the second end of the secondary winding of the first transformer are all connected to the first ground, and the first end of the secondary winding of the first transformer outputs the second sinusoidal wave signal.

[0012] In one or more embodiments, when the Class D power amplifier has a differential output, the second signal conversion module includes a second filtering unit, a third filtering unit, and a second boosting unit; the second filtering unit and the third filtering unit are both connected between the Class D power amplifier and the second boosting unit, and the second filtering unit and the third filtering unit are used to filter the high-frequency carrier pulse width modulation signal to demodulate the high-frequency carrier pulse width modulation signal; the second boosting unit is used to boost the demodulated signal of the high-frequency carrier pulse width modulation signal and output the second sinusoidal wave signal.

[0013] In one or more embodiments, the second filtering unit includes a third capacitor and a second inductor, the third filtering unit includes a fourth capacitor and a third inductor, and the second boost unit includes a second transformer; the first end of the second inductor is connected to the in-phase output terminal of the class D power amplifier, the second end of the second inductor is respectively connected to the first end of the third capacitor and the first end of the primary winding of the second transformer, the first end of the third inductor is connected to the inverting output terminal of the class D power amplifier, the second end of the third inductor is respectively connected to the first end of the fourth capacitor and the second end of the primary winding of the second transformer, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the secondary winding of the second transformer are connected to the first ground, and the first end of the secondary winding of the second transformer outputs the second sinusoidal wave signal.

[0014] In one or more embodiments, the voltage control module includes a signal processing unit, a voltage sampling unit and a signal output unit; the signal processing unit is connected to the signal output unit, the signal processing unit inputs the control signal, and the signal processing unit is used to perform level conversion on the control signal and output it to the signal output unit; the voltage sampling unit is connected between the second signal conversion module and the signal output unit, the voltage acquisition unit is used to sample the second sinusoidal wave signal, and output a second voltage corresponding to the second sinusoidal wave signal to the signal output unit; the signal output unit is connected to the first signal conversion module, the signal output unit is used to generate a first voltage corresponding to the control signal after level conversion, and output the adjustment signal to the first signal conversion module based on the first voltage and the second voltage.

[0015] In one or more embodiments, the control signal is a pulse width modulation signal, and the signal processing unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an inverter and a fifth capacitor; the first end of the first resistor, the power supply end of the inverter, the first end of the fifth capacitor and the first end of the fourth resistor are all connected to the first power supply, the second end of the first resistor is respectively connected to the first end of the second resistor and the pulse width modulation signal, the second end of the second resistor is connected to the input end of the inverter, the output end of the inverter is connected to the first end of the third resistor, the second end of the third resistor is respectively connected to the second end of the fourth resistor and the signal output unit, and the second end of the fifth capacitor is connected to the second ground.

[0016] In one or more embodiments, the voltage sampling unit includes a fifth resistor, a sixth resistor, a seventh resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a first diode and a second diode; the first end of the sixth capacitor is connected to the second signal conversion module, the second end of the sixth capacitor is respectively connected to the first end of the fifth resistor, the first end of the seventh capacitor and the anode of the first diode, the cathode of the first diode is connected to the first end of the sixth resistor, the second end of the sixth resistor is respectively connected to the first end of the seventh resistor, the first end of the eighth capacitor, the cathode of the second diode and the signal output unit, and the second end of the seventh capacitor, the second end of the fifth resistor, the second end of the eighth capacitor, the second end of the seventh resistor and the cathode of the second diode are all connected to the second ground.

[0017] In one or more embodiments, the signal output unit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a ninth capacitor, a tenth capacitor and an operational amplifier; the first end of the eighth resistor is connected to the voltage sampling unit, the second end of the eighth resistor is respectively connected to the first end of the ninth capacitor and the inverting input terminal of the operational amplifier, the second end of the ninth capacitor is connected to the first end of the ninth resistor, the second end of the ninth resistor is respectively connected to the first end of the tenth resistor and the output terminal of the operational amplifier, the second end of the tenth resistor is respectively connected to the first end of the eleventh resistor and the first signal conversion module, the second end of the eleventh resistor and the first end of the tenth capacitor are both connected to the second ground, the second end of the tenth capacitor is respectively connected to the first end of the twelfth resistor and the non-inverting input terminal of the operational amplifier, and the second end of the twelfth resistor is connected to the signal processing unit.

[0018] In a second aspect, the present application provides an electronic device, comprising an electrical load and the sine wave generating circuit as described above;

[0019] The sine wave generating circuit is connected to the electrical load to supply power to the electrical load.

[0020] The beneficial effects of the present application are as follows: The sine wave generation circuit provided by the present application includes a first signal conversion module, a Class D power amplifier, a second signal conversion module, and a voltage control module. The first signal conversion module inputs a square wave signal and is used to convert the square wave signal into a first sine wave signal with adjustable amplitude. The Class D power amplifier is connected to the first signal conversion module and inputs the first sine wave signal. The Class D power amplifier is used to amplify and modulate the power of the first sine wave signal and output a high-frequency carrier pulse-width modulated signal. The second signal conversion module is connected to the Class D power amplifier and inputs a high-frequency carrier pulse-width modulated signal. The second signal conversion module is used to demodulate and boost the high-frequency carrier pulse-width modulated signal and output a second sine wave signal. The voltage control module is connected between the second signal conversion module and the first signal conversion module and inputs the second sine wave signal and a control signal. The voltage control module is used to output an adjustment signal to the first signal conversion module based on the control signal and the second sine wave signal to adjust the amplitude of the first sine wave signal until the voltage of the control signal and the second sine wave signal meet a preset relationship. As can be seen, users can adjust the amplitude of the first sine wave signal based on their needs by adjusting the control signal, thereby adjusting the voltage of the second sine wave signal to meet their needs. Furthermore, by using a Class D amplifier to generate the second sine wave signal, high conversion efficiency is achieved, thereby increasing the reliability of the entire sine wave generation circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0022] FIG1 is a schematic structural diagram of a sine wave generating circuit provided in Example 1 of the present application;

[0023] FIG2 is a schematic structural diagram of a sine wave generating circuit provided in Example 2 of the present application;

[0024] FIG3 is a schematic diagram of the circuit structure of a sine wave generating circuit provided in Example 1 of the present application;

[0025] FIG4 is a schematic diagram of various signals in a sine wave generating circuit provided in Example 1 of the present application;

[0026] FIG5 is a schematic diagram of the structure of a sine wave generating circuit provided in Example 3 of the present application;

[0027] FIG6 is a schematic diagram of the circuit structure of the sine wave generating circuit provided in Example 1 of the present application. DETAILED DESCRIPTION

[0028] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] Please refer to Figure 1, which is a schematic diagram of the structure of a sine wave generating circuit according to an embodiment of the present invention. As shown in Figure 1, the sine wave generating circuit 100 includes a first signal conversion module 10, a class D power amplifier U1, a second signal conversion module 20 and a voltage control module 30.

[0030] The class D power amplifier U1 is connected to the first signal conversion module 10 , the second signal conversion module 10 is connected to the class D power amplifier U1 , and the voltage control module 30 is connected between the second signal conversion module 20 and the first signal conversion module 10 .

[0031] Specifically, the first signal conversion module 10 receives a square wave signal VCLK, which, in some embodiments, is a clock signal. The first signal conversion module 10 is configured to convert the square wave signal VCLK into a first sinusoidal signal with adjustable amplitude. The first sinusoidal signal is received by a Class D power amplifier U1. The Class D power amplifier U1 amplifies and modulates the power of the first sinusoidal signal to output a high-frequency carrier pulse-width modulated signal with a variable duty cycle. The second signal conversion module 20 receives a high-frequency carrier pulse-width modulated signal. The second signal conversion module 20 demodulates and boosts the high-frequency carrier pulse-width modulated signal to output a second sinusoidal signal VSIN2. The voltage control module 30 receives the second sinusoidal signal VSIN2 and a control signal VCO. Based on the control signal VCO and the second sinusoidal signal VSIN2, the voltage control module 30 outputs a regulation signal to the first signal conversion module 10 to adjust the amplitude of the first sinusoidal signal until the voltages of the control signal VCO and the second sinusoidal signal VSIN2 meet a predetermined relationship.

[0032] The second sinusoidal wave signal VSIN2 is used to power an electrical load. For example, when the sinusoidal wave generating circuit is applied to an electronic device, the second sinusoidal wave signal VSIN2 is used to power an electrical load in the electronic device. For example, if the electronic device is a printer, the second sinusoidal wave signal VSIN2 can be used to power an ink cartridge (i.e., an electrical load) in the printer.

[0033] The preset relationship is a pre-set correspondence between the voltage of the control signal VCO and the second sine wave signal VSIN2. The specific setting can be based on actual application scenarios and is not specifically limited in the embodiments of the present application. For example, in some embodiments, the preset relationship can be set so that the voltage of the control signal VCO and the second sine wave signal VSIN2 are proportional; while in other embodiments, the proportional relationship can even be set to 1:1, that is, the actual preset relationship is that the voltage of the control signal VCO is equal to the voltage of the second sine wave signal VSIN2.

[0034] In actual applications, when a user needs to adjust the voltage of the second sine wave signal VSIN2, a control signal VCO corresponding to the requirement is output. At this point, if the voltages of the control signal VCO and the second sine wave signal VSIN2 do not satisfy a preset relationship, the voltage control module 30 outputs a corresponding adjustment signal to the first signal conversion module 10 to adjust the amplitude of the first sine wave signal. Subsequently, the high-frequency carrier pulse-width modulation signal and the second sine wave signal VSIN2 are adjusted sequentially until the voltages of the control signal VCO and the second sine wave signal VSIN2 again satisfy the preset relationship. Thus, through the above process, the voltage of the second sine wave signal can be automatically adjusted to meet user requirements, that is, a corresponding sine wave signal can be output according to user requirements. At the same time, by using a Class D power amplifier to generate the second sine wave signal, a higher conversion efficiency can be achieved, thereby preventing severe heating or even damage to components when the voltage changes, which is conducive to maintaining stable operation of each component, and thus improving the reliability of the entire sine wave generation circuit 100.

[0035] In one embodiment, as shown in FIG2 , the first signal conversion module 10 includes a signal conversion unit 11 and a signal amplification unit 12 , wherein the signal amplification unit 12 is connected to the signal conversion unit 11 .

[0036] Specifically, the signal conversion unit 11 receives a square wave signal as input. The signal conversion unit 11 is configured to convert the square wave signal into a third sinusoidal wave signal. The signal amplification unit 12 receives the third sinusoidal wave signal as input. The signal amplification unit 12 is configured to output a first sinusoidal wave signal based on the third sinusoidal wave signal.

[0037] Among them, the amplitude of the first sinusoidal wave signal is determined by the amplitude of the third sinusoidal wave signal and the gain of the signal amplification unit. Specifically, the product of the amplitude of the third sinusoidal wave signal and the gain of the signal amplification unit 12 is the amplitude of the first sinusoidal wave signal. The gain of the signal amplification unit 12 is determined by the voltage of the adjustment signal output by the voltage control module 30. It can be seen that by changing the voltage of the adjustment signal, the gain of the signal amplification unit 12 can be changed, and then the amplitude of the first sinusoidal wave signal can be changed when the amplitude of the third sinusoidal wave signal remains unchanged. That is, the amplitude of the first sinusoidal wave signal is adjustable and can be adjusted by the adjustment signal.

[0038] In this embodiment, the class D power amplifier U1 has a single-ended output, and the second signal conversion module 20 includes a first filtering unit 21 and a first boosting unit 22. The first filtering unit 21 is connected between the class D power amplifier U1 and the first boosting unit 22.

[0039] Specifically, the first filtering unit 21 is used to filter the high-frequency carrier pulse width modulated signal to demodulate the high-frequency carrier pulse width modulated signal. The first boosting unit 22 is used to boost the demodulated signal of the high-frequency carrier pulse width modulated signal and output a second sinusoidal wave signal. That is, the class D power amplifier U1 outputs a high-frequency carrier pulse width modulated signal, which is filtered by the first filtering unit 21 (at which point it is demodulated into a sinusoidal wave again) and boosted by the first boosting unit 22 to become the second sinusoidal wave signal VSIN2. It can be seen that the second sinusoidal wave signal VSIN2 obtained after power amplification by the class D power amplifier U1 and boosting by the first boosting unit 22 can meet the application scenarios that require high power and high voltage power supply. Among them, in the embodiments of the present application, the second sinusoidal wave signal VSIN2 refers to a high-voltage sine wave, mainly a voltage greater than or equal to 1000V.

[0040] In one embodiment, the voltage control module 30 includes a signal processing unit 31, a voltage sampling unit 32, and a signal output unit 33. The signal processing unit 31 is connected to the signal output unit 33. The voltage sampling unit 31 is connected between the second signal conversion module 20 and the signal output unit 33. The signal output unit 33 is connected to the first signal conversion module 10.

[0041] Specifically, the signal processing unit 31 inputs a control signal VCO. The signal processing unit 31 is configured to output a voltage that is level-converted with the control signal VCO and output it to the signal output unit 33. The voltage acquisition unit 32 is configured to sample the second sinusoidal signal and output a second voltage corresponding to the second sinusoidal signal to the signal output unit 33. The signal output unit 33 is configured to generate a first voltage corresponding to the level-converted control signal VCO and output an adjustment signal to the first signal conversion module 10 based on the first and second voltages. The signal output unit 33 outputs the adjustment signal to the first signal conversion module 10 to adjust the amplitude of the first sinusoidal signal until the first and second voltages satisfy a predetermined relationship. In some embodiments, the predetermined relationship between the first and second voltages is that the first and second voltages are equal. Subsequently, when a user needs to obtain a second voltage of a certain voltage value, they only need to output the control signal VCO corresponding to that voltage value, which is more convenient. The control signal VCO can be any signal that can be converted into a voltage, such as a pulse width modulation (PWM) signal.

[0042] Please refer to FIG. 3 , which exemplarily shows a circuit structure corresponding to the structure shown in FIG. 2 .

[0043] In one embodiment, as shown in FIG3 , the signal conversion unit 11 includes a square wave to sinusoidal wave conversion module U2 .

[0044] The square wave-to-sine wave module U2 receives a square wave signal VCLK at its input terminal INPUT and outputs a third sinusoidal signal at its output terminal OUT. The power supply terminal VCC of the square wave-to-sine wave module U2 is connected to the input power supply VIN via a fuse F1 to be powered by the input power supply VIN. The square wave signal VCLK has the same frequency as the third sinusoidal wave signal. In some embodiments, the square wave-to-sine wave module U2 can utilize a module such as the RT8H415C.

[0045] In one embodiment, the signal amplification unit 12 includes a sine wave amplification module U3 .

[0046] The input terminal SIN of the sine wave amplifier module U3 inputs the third sine wave signal, and the output terminal OUT outputs the first sine wave signal. The power supply terminal VCC of the sine wave amplifier module U3 is connected to the input power supply VIN through the fuse F1 to be powered by the input power supply VIN.

[0047] In one embodiment, the input terminal RIN of the class D power amplifier U1 inputs a third sinusoidal wave signal, and the output terminal ROUT outputs a high-frequency carrier pulse-width modulation signal. The power supply terminal VCC of the class D power amplifier U1 is connected to the input power supply VIN through a fuse F1 to be powered by the input power supply VIN.

[0048] In one embodiment, the first filtering unit 21 includes a first inductor L1 , a first capacitor C1 , and a second capacitor C2 , and the first boosting unit 22 includes a first transformer T1 .

[0049] The first end of the first inductor L1 is connected to the class D power amplifier U1, the second end of the first inductor L1 is respectively connected to the first end of the first capacitor C1 and the first end of the second capacitor C2, the second end of the first capacitor C1 is connected to the first end of the primary winding of the first transformer T1, the second end of the second capacitor C2, the second end of the primary winding of the first transformer T1, and the second end of the secondary winding of the first transformer T1 are all connected to the first ground PG, and the first end of the secondary winding of the first transformer T1 outputs the second sinusoidal wave signal VSIN2. In the embodiment of the present application, the first ground PG is the ground of the circuit that transmits power, and the second ground SG is the ground of the circuit that transmits signals.

[0050] Specifically, the first inductor L1 , the first capacitor C1 and the second capacitor C2 form a low-pass filter combination to demodulate the high-frequency carrier pulse-width modulation signal into the fourth sinusoidal wave signal.

[0051] In one embodiment, the control signal is a pulse width modulation signal, and the signal processing unit 31 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, an inverter NO1, and a fifth capacitor C5.

[0052] Among them, the first end of the first resistor R1, the power supply end of the inverter NO1, the first end of the fifth capacitor C5, and the first end of the fourth resistor R4 are all connected to the first power supply V1. The second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the pulse width modulation signal. The second end of the second resistor R2 is connected to the input end of the inverter NO1. The output end of the inverter NO1 is connected to the first end of the third resistor R3. The second end of the third resistor R3 is respectively connected to the second end of the fourth resistor R4 and the signal output unit 33. The second end of the fifth capacitor C5 is connected to the second ground SG.

[0053] Specifically, the first resistor R1 is a pull-up resistor, and the second resistor R2 is an input protection resistor. Inverter NO1 is capable of inverting the duty cycle of the pulse-width modulated signal. The third resistor R3 and the fourth resistor R4 are voltage-divider resistors. By providing the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the inverter NO1, the pulse-width modulated signal can be level-converted, thereby improving the pulse-width modulated signal's anti-interference capability. This prevents interference with the pulse-width modulated signal that could affect subsequent control processes, thereby improving the stability and reliability of the entire sine wave generation circuit 100.

[0054] In one embodiment, the voltage sampling unit 32 includes a fifth resistor R5 , a sixth resistor R6 , a seventh resistor R7 , a sixth capacitor C6 , a seventh capacitor C7 , an eighth capacitor C8 , a first diode D1 , and a second diode D2 .

[0055] Among them, the first end of the sixth capacitor C6 is connected to the second signal conversion module 20, the second end of the sixth capacitor C6 is respectively connected to the first end of the fifth resistor R5, the first end of the seventh capacitor C7 and the anode of the first diode D1, the cathode of the first diode D1 is connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is respectively connected to the first end of the seventh resistor R7, the first end of the eighth capacitor C8, the cathode of the second diode D2 and the signal output unit 33, and the second end of the seventh capacitor C7, the second end of the fifth resistor R5, the second end of the eighth capacitor C8, the second end of the seventh resistor R7 and the cathode of the second diode D2 are all connected to the second ground SG.

[0056] Specifically, the sixth capacitor C6, the seventh capacitor C7, the eighth capacitor C8, and the fifth resistor R5 are used for filtering. The first diode D1 is used for rectification. The sixth resistor R6 and the seventh resistor R7 are used for voltage division. The second diode D2 is used to filter any negative voltage. Through the above filtering and rectification process, the second sinusoidal wave signal VSIN2 can be converted to a specific voltage value (i.e., the second voltage).

[0057] In one embodiment, the signal output unit 33 includes an eighth resistor R8 , a ninth resistor R9 , a tenth resistor R10 , an eleventh resistor R11 , a twelfth resistor R12 , a ninth capacitor C9 , a tenth capacitor C10 , and an operational amplifier U4 .

[0058] Among them, the first end of the eighth resistor R8 is connected to the voltage sampling unit 32, the second end of the eighth resistor R8 is respectively connected to the first end of the ninth capacitor C9 and the inverting input terminal of the operational amplifier U4, the second end of the ninth capacitor C9 is connected to the first end of the ninth resistor R9, the second end of the ninth resistor R9 is respectively connected to the first end of the tenth resistor R10 and the output terminal of the operational amplifier U4, the second end of the tenth resistor R10 is respectively connected to the first end of the eleventh resistor R11 and the first signal conversion module 10 (that is, the feedback input terminal VCCON of the sinusoidal wave amplification module U3), the second end of the eleventh resistor R11 and the first end of the tenth capacitor C10 are both connected to the second ground SG, the second end of the tenth capacitor C10 is respectively connected to the first end of the twelfth resistor R12 and the non-inverting input terminal of the operational amplifier U4, and the second end of the twelfth resistor R12 is connected to the signal processing unit 31.

[0059] Specifically, the twelfth resistor R12 and the tenth capacitor C10 function as an integrator to convert the level-converted control signal VCO into the first voltage. The eighth resistor R8 protects the operational amplifier U4. The ninth resistor R9 and the ninth capacitor C9 function as feedback. The tenth resistor R10 and the eleventh resistor R11 are used for voltage division to output a suitable voltage to the feedback input terminal VCCON of the sine wave amplifier module U3.

[0060] In this embodiment, the first voltage is input to the non-inverting input terminal of the operational amplifier U4, and the second voltage is input to the inverting input terminal of the operational amplifier U4. When the first voltage is not equal to the second voltage, the voltage output by the operational amplifier U4 is divided by the tenth resistor R10 and the eleventh resistor R11 (which corresponds to the adjustment signal in the above embodiment) and input to the feedback input terminal VCCON of the sine wave amplifier module U3 to adjust the gain of the sine wave amplifier module U3, so as to adjust the magnitude of the second voltage by adjusting the second sine wave signal VSIN2. The difference between the second voltage and the first voltage gradually decreases. Until the first voltage is equal to the second voltage, the entire system is in a stable state, and the gain of the sine wave amplifier module U3 remains unchanged.

[0061] Please refer to Figure 4, which illustrates a schematic diagram of various signals in the sine wave generation circuit 100 shown in Figure 3 in one embodiment. The horizontal axis represents time. The vertical signals, from top to bottom, are: square wave signal VCLK; first sine wave signal VSIN1 output by square wave-to-sine wave conversion module U2; high-frequency carrier pulse-width modulation signal VSPWM output by Class-D amplifier U1; fourth sine wave signal VSIN4 output by first filter unit 21; and second sine wave signal VSIN2 output by first boost unit 22.

[0062] As shown in Figure 4, the square wave signal VCLK is input to the square wave conversion sine wave module U2 and converted into a first sine wave signal VSIN1. The first sine wave signal VSIN1 is input to the sine wave amplification module U3, which outputs a third sine wave signal VSIN3. In this embodiment, assuming that the gain of the sine wave amplification module U3 is 1 when the entire sine wave generation circuit 100 is operating stably, the third sine wave signal VSIN3 is the same as the first sine wave signal VSIN1. This is equivalent to inputting the first sine wave signal VSIN1 into the Class D power amplifier U1. The Class D power amplifier U1 performs power amplification and modulation, then outputs a high-frequency carrier pulse-width modulated signal VSPWM. The high-frequency carrier pulse-width modulated signal VSPWM is input to the first filtering unit 21, filtered, and converted into a fourth sine wave signal VSIN4. Due to power amplification, the fourth sine wave signal VSIN4 has a stronger driving capability than the third sine wave signal VSIN3 and the first sine wave signal VSIN1. Finally, the fourth sine wave signal VSIN4 is input to the first transformer T1 and is boosted to obtain the second sine wave signal VSIN2. Therefore, the second sine wave signal VSIN2 is a high-voltage sine wave with a strong driving capability.

[0063] It should be noted that the hardware structure of the sine wave generating circuit 100 shown in Figures 2 and 3 is merely an example, and the sine wave generating circuit 100 may have more or fewer components than shown in the figures, may combine two or more components, or may have different component configurations. The various components shown in the figures may be implemented in hardware, including one or more signal processing and / or application-specific integrated circuits, software, or a combination of hardware and software.

[0064] For example, Figures 2 and 3 use a single-ended output Class D amplifier, but in other implementations, a differential output Class D amplifier may also be used. In a single-ended output Class D amplifier, the output signals are all referenced to a common ground, while in a differential output Class D amplifier, each output signal has its own reference ground.

[0065] 5 , when a Class D power amplifier with differential output is used, the second signal conversion module 20 includes a second filtering unit 23, a third filtering unit 24, and a second boosting unit 25. The second filtering unit 23 and the third filtering unit 24 are both connected between the Class D power amplifier U1 and the second boosting unit 25.

[0066] Specifically, the second filtering unit 23 and the third filtering unit 24 are used to filter the high-frequency carrier pulse-width modulated signal to demodulate the high-frequency carrier pulse-width modulated signal. The second boosting unit 25 is used to boost the demodulated high-frequency carrier pulse-width modulated signal and output the second sinusoidal wave signal VSIN2. The specific implementation process can be referred to the detailed description of the first filtering unit 21 and the first boosting unit 22, and will not be repeated here.

[0067] Fig. 6 also exemplarily shows a circuit structure corresponding to Fig. 5. The parts of the circuit structure shown in Fig. 6 that are identical to those shown in Fig. 3 can be referred to the description of Fig. 3 and will not be repeated here.

[0068] As shown in FIG6 , the second filtering unit 23 includes a third capacitor C3 and a second inductor L2 , the third filtering unit 24 includes a fourth capacitor C4 and a third inductor L3 , and the second boost unit 25 includes a second transformer T2 .

[0069] Among them, the first end of the second inductor L2 is connected to the in-phase output terminal of the class D power amplifier U1, the second end of the second inductor L2 is respectively connected to the first end of the third capacitor C3 and the first end of the primary winding of the second transformer T2, the first end of the third inductor L3 is connected to the inverting output terminal of the class D power amplifier U1, the second end of the third inductor L3 is respectively connected to the first end of the fourth capacitor C4 and the second end of the primary winding of the second transformer T2, the second end of the third capacitor C3, the second end of the fourth capacitor C4 and the second end of the secondary winding of the second transformer T2 are connected to the first ground PG, and the first end of the secondary winding of the second transformer T2 outputs the second sinusoidal wave signal VSIN2.

[0070] Specifically, the third capacitor C3 and the second inductor L2 form a low-pass filter combination; the fourth capacitor C4 and the third inductor L3 also form a low-pass filter combination, thereby being able to demodulate the high-frequency carrier pulse width modulation signal into a fourth sinusoidal wave signal.

[0071] The present application also provides an electronic device, which includes an electrical load and a sine wave generating circuit 100 as in any embodiment of the present application. The sine wave generating circuit 100 is connected to the electrical load to supply power to the electrical load.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A sine wave generating circuit, characterized in that: include: a first signal conversion module, the first signal conversion module inputting a square wave signal, and the first signal conversion module being configured to convert the square wave signal into a first sine wave signal with adjustable amplitude; a class D power amplifier connected to the first signal conversion module, the class D power amplifier inputting the first sinusoidal wave signal, and configured to amplify and modulate the power of the first sinusoidal wave signal and then output a high-frequency carrier pulse-width modulation signal; a second signal conversion module, the second signal conversion module being connected to the class D power amplifier, the second signal conversion module inputting the high-frequency carrier pulse width modulation signal, and the second signal conversion module being configured to demodulate and boost the high-frequency carrier pulse width modulation signal and then output a second sinusoidal wave signal; A voltage control module is connected between the second signal conversion module and the first signal conversion module. The voltage control module inputs the second sinusoidal wave signal and the control signal. The voltage control module is used to output an adjustment signal to the first signal conversion module based on the control signal and the second sinusoidal wave signal to adjust the amplitude of the first sinusoidal wave signal until the voltage of the control signal and the second sinusoidal wave signal meet a preset relationship.

2. The sine wave generating circuit according to claim 1, wherein: The first signal conversion module includes a signal conversion unit and a signal amplification unit; The signal conversion unit inputs the square wave signal, and the signal conversion unit is used to convert the square wave signal into a third sinusoidal wave signal; The signal amplification unit is connected to the signal conversion unit, the signal amplification unit inputs the third sinusoidal wave signal, and the signal conversion unit is used to output the first sinusoidal wave signal based on the third sinusoidal wave signal, wherein the amplitude of the first sinusoidal wave signal is determined by the amplitude of the third sinusoidal wave signal and the gain of the signal amplification unit.

3. The sine wave generating circuit according to claim 1, wherein: When the class D power amplifier is a single-ended output, the second signal conversion module includes a first filtering unit and a first boosting unit; The first filtering unit is connected between the class D power amplifier and the first boost unit, and is used to filter the high-frequency carrier pulse width modulation signal to demodulate the high-frequency carrier pulse width modulation signal; The first boosting unit is used to boost the demodulated signal of the high-frequency carrier pulse width modulation signal and then output the second sinusoidal wave signal.

4. The sine wave generating circuit according to claim 3, wherein: The first filtering unit includes a first inductor, a first capacitor and a second capacitor, and the first boosting unit includes a first transformer; The first end of the first inductor is connected to the Class D power amplifier, the second end of the first inductor is respectively connected to the first end of the first capacitor and the first end of the second capacitor, the second end of the first capacitor is connected to the first end of the primary winding of the first transformer, the second end of the second capacitor, the second end of the primary winding of the first transformer and the second end of the secondary winding of the first transformer are all connected to the first ground, and the first end of the secondary winding of the first transformer outputs the second sinusoidal wave signal.

5. The sine wave generating circuit according to claim 1, wherein: When the class D power amplifier is a differential output, the second signal conversion module includes a second filtering unit, a third filtering unit and a second boost unit; The second filtering unit and the third filtering unit are both connected between the class D power amplifier and the second boost unit, and the second filtering unit and the third filtering unit are used to filter the high-frequency carrier pulse width modulation signal to demodulate the high-frequency carrier pulse width modulation signal; The second boosting unit is used to boost the demodulated signal of the high-frequency carrier pulse width modulation signal and then output the second sinusoidal wave signal.

6. The sine wave generating circuit according to claim 5, wherein: The second filtering unit includes a third capacitor and a second inductor, the third filtering unit includes a fourth capacitor and a third inductor, and the second boost unit includes a second transformer; The first end of the second inductor is connected to the in-phase output terminal of the class D power amplifier, the second end of the second inductor is respectively connected to the first end of the third capacitor and the first end of the primary winding of the second transformer, the first end of the third inductor is connected to the inverting output terminal of the class D power amplifier, the second end of the third inductor is respectively connected to the first end of the fourth capacitor and the second end of the primary winding of the second transformer, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the secondary winding of the second transformer are connected to the first ground, and the first end of the secondary winding of the second transformer outputs the second sinusoidal wave signal.

7. The sine wave generating circuit according to claim 1, wherein: The voltage control module includes a signal processing unit, a voltage sampling unit and a signal output unit; The signal processing unit is connected to the signal output unit, the signal processing unit inputs the control signal, and the signal processing unit is used to perform level conversion on the control signal and output the level conversion to the signal output unit; The voltage sampling unit is connected between the second signal conversion module and the signal output unit, and is used to sample the second sinusoidal wave signal and output a second voltage corresponding to the second sinusoidal wave signal to the signal output unit; The signal output unit is connected to the first signal conversion module, and is used to generate a first voltage corresponding to the control signal after level conversion, and output the adjustment signal to the first signal conversion module based on the first voltage and the second voltage.

8. The sine wave generating circuit according to claim 7, wherein: The control signal is a pulse width modulation signal, and the signal processing unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an inverter and a fifth capacitor; The first end of the first resistor, the power supply end of the inverter, the first end of the fifth capacitor, and the first end of the fourth resistor are all connected to a first power supply. The second end of the first resistor is respectively connected to the first end of the second resistor and the pulse width modulation signal. The second end of the second resistor is connected to the input end of the inverter. The output end of the inverter is connected to the first end of the third resistor. The second end of the third resistor is respectively connected to the second end of the fourth resistor and the signal output unit. The second end of the fifth capacitor is connected to a second ground.

9. The sine wave generating circuit according to claim 7, wherein: The voltage sampling unit includes a fifth resistor, a sixth resistor, a seventh resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a first diode and a second diode; The first end of the sixth capacitor is connected to the second signal conversion module, the second end of the sixth capacitor is respectively connected to the first end of the fifth resistor, the first end of the seventh capacitor and the anode of the first diode, the cathode of the first diode is connected to the first end of the sixth resistor, the second end of the sixth resistor is respectively connected to the first end of the seventh resistor, the first end of the eighth capacitor, the cathode of the second diode and the signal output unit, and the second end of the seventh capacitor, the second end of the fifth resistor, the second end of the eighth capacitor, the second end of the seventh resistor and the cathode of the second diode are all connected to the second ground.

10. The sine wave generating circuit according to claim 7, wherein: The signal output unit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a ninth capacitor, a tenth capacitor and an operational amplifier; The first end of the eighth resistor is connected to the voltage sampling unit, the second end of the eighth resistor is respectively connected to the first end of the ninth capacitor and the inverting input terminal of the operational amplifier, the second end of the ninth capacitor is connected to the first end of the ninth resistor, the second end of the ninth resistor is respectively connected to the first end of the tenth resistor and the output terminal of the operational amplifier, the second end of the tenth resistor is respectively connected to the first end of the eleventh resistor and the first signal conversion module, the second end of the eleventh resistor and the first end of the tenth capacitor are both connected to the second ground, the second end of the tenth capacitor is respectively connected to the first end of the twelfth resistor and the non-inverting input terminal of the operational amplifier, and the second end of the twelfth resistor is connected to the signal processing unit.

11. An electronic device, characterized in that: comprising an electrical load and a sine wave generating circuit as claimed in any one of claims 1 to 10; The sine wave generating circuit is connected to the electrical load to supply power to the electrical load.

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