Audio power amplifier modulation circuit, method, apparatus, and computer storage medium

Abstract

The application relates to the field of signal modulation and discloses an audio power amplifier modulation circuit, method, device and computer storage medium, the circuit comprises a selection unit, a modulation unit, a driving signal generation unit, a power output unit comprising a wide band gap semiconductor transistor, a low pass filter unit connected in sequence, the low pass filter unit is connected with a load, the power output unit and the modulation unit are connected with a feedback unit; the selection unit selects a modulation mode, the modulation unit obtains a pulse modulation signal based on the modulation mode and a feedback signal by receiving a signal to be modulated, the driving signal generation unit determines a driving signal according to the pulse modulation signal, the power output unit obtains a power output signal according to the driving signal and the pulse modulation signal, the low pass filter unit filters the power output signal to obtain a load driving signal, and the feedback unit determines the feedback signal according to the power output signal. The application effectively suppresses the power consumption and heat of the power transistor, and realizes the miniaturization development of the audio power amplifier modulation.

Description

Technical Field

[0001] This application relates to the field of signal modulation, and more particularly to an audio power amplifier modulation circuit, method, device, and computer storage medium. Background Technology

[0002] With the rapid development of information technology, audio amplifiers are being used more and more in fields such as signal processing. At the same time, there are higher requirements for the sound quality and portability of audio amplifiers, and portability is becoming increasingly important, especially for small audio devices.

[0003] Traditional audio power amplifier modulation uses MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) as the power transistors to convert the raw audio input into a pulse signal. This method has significant drawbacks. Due to the large junction capacitance of the MOSFETs, when the modulation frequency exceeds 500kHz, the power consumption and heat generation of the MOSFETs become difficult to control. This necessitates increasing the size of the filter inductor and adding a heatsink to achieve the desired sound quality. In other words, this method limits the miniaturization of audio power amplifier modulation due to the need for larger filter inductors and heatsinks. Summary of the Invention

[0004] The main purpose of this application is to propose an audio power amplifier modulation circuit, method, device and computer storage medium, which aims to effectively suppress the power consumption and heat generation of power transistors, thereby realizing the miniaturization of audio power amplifier modulation.

[0005] To achieve the above objectives, embodiments of this application provide an audio power amplifier modulation circuit, which includes a modulation unit, a drive signal generation unit, a power output unit, a low-pass filter unit, a feedback unit, and a selection unit.

[0006] The modulation output terminal of the modulation unit, the drive signal generation unit, the power output unit, and the low-pass filter unit are connected in sequence. The output terminal of the low-pass filter unit is connected to the load. The output terminal of the power output unit is connected to the input terminal of the feedback unit. The output terminal of the feedback unit is connected to the feedback terminal of the modulation unit. The selection unit is connected to the input terminal of the modulation unit. The power amplifier transistor of the power output unit includes a wide bandgap semiconductor transistor.

[0007] The selection unit is used to select the modulation mode of the modulation unit. The modulation unit is used to receive the signal to be modulated and the feedback signal, and to perform pulse modulation on the signal to be modulated based on the modulation mode and the feedback signal to obtain a pulse modulation signal. The drive signal generation unit is used to determine a drive signal based on the pulse modulation signal. The power output unit is used to amplify the power of the pulse modulation signal based on the drive signal to obtain a power output signal. The low-pass filter unit is used to filter the power output signal to obtain a load drive signal. The feedback unit is used to determine the feedback signal based on the power output signal.

[0008] Optionally, the power output unit includes a wide bandgap semiconductor transistor and a heat sink. The driving stage of the wide bandgap semiconductor transistor is connected to the driving signal generation unit, and the power output stage of the wide bandgap semiconductor transistor is connected to the input terminal of the low-pass filter unit. A heat dissipation material is disposed on the heat sink, and one end of the heat dissipation material is disposed on the heat dissipation surface of the wide bandgap semiconductor transistor. The heat dissipation material includes thermally conductive silicone or thermally conductive grease. The wide bandgap semiconductor transistor is used to receive the driving signal sent by the driving signal generation unit and to amplify the pulse modulation signal based on the driving signal to obtain a power output signal.

[0009] Optionally, the wide bandgap semiconductor transistor includes a gallium nitride transistor or a silicon carbide transistor.

[0010] Optionally, the drive signal generation unit includes a gate driver, the input terminal of which is connected to the modulation output terminal of the modulation unit, and the output terminal of which is connected to the drive stage of the wide bandgap semiconductor transistor. The gate driver is used to determine the drive signal based on the pulse modulation signal.

[0011] Optionally, the low-pass filter unit includes at least one filter inductor and at least one filter capacitor. The first end of the filter inductor is connected to the power output stage of the wide bandgap semiconductor transistor, and the second end of the filter inductor is connected to the first end of the filter capacitor and the load, respectively. The second end of the filter capacitor is grounded. The low-pass filter unit is used to filter out high-frequency components in the power output signal to obtain the load drive signal.

[0012] Optionally, the modulation unit includes an adder and a pulse modulation circuit. The pulse modulation circuit includes a positive input terminal, a negative input terminal, and a modulation output terminal. The first terminal of the adder is connected to the interface of the signal to be modulated, the second terminal of the adder is connected to the output terminal of the feedback unit, the output terminal of the adder is connected to the positive input terminal, the negative input terminal is connected to the carrier signal interface, and the modulation output terminal is connected to the input terminal of the gate driver.

[0013] Furthermore, to achieve the above objectives, this application also provides an audio power amplifier modulation method, which is applied to the audio power amplifier modulation circuit. The steps of the audio power amplifier modulation method include:

[0014] The signal to be modulated is received through the modulation unit;

[0015] If an input feedback signal is received, the signal to be modulated is pulse modulated based on the feedback signal to obtain a pulse modulated signal, wherein the feedback signal includes the output signal of the feedback unit, and the pulse modulated signal includes the signal to be modulated after pulse modulation;

[0016] The driving signal corresponding to the pulse modulation signal is determined in the driving signal generation unit;

[0017] The power output signal is obtained by amplifying the pulse modulation signal in the power output unit according to the driving signal.

[0018] The power output signal is filtered by the low-pass filter unit to obtain the load drive signal, and the load is driven based on the load drive signal.

[0019] Optionally, after the step of receiving the signal to be modulated via the modulation unit, the following steps are included:

[0020] The modulation unit receives a carrier signal through a pulse modulation circuit and performs pulse modulation on the signal to be modulated based on the carrier signal to obtain a pulse modulated signal.

[0021] In addition, to achieve the above objectives, this application embodiment also provides an audio power amplifier modulation device, including: a memory, a processor, and an audio power amplifier modulation program stored in the memory and executable on the processor. When the audio power amplifier modulation program is executed by the processor, it implements the steps of the audio power amplifier modulation method described above.

[0022] In addition, to achieve the above objectives, this application also provides a computer storage medium for audio power amplifier modulation, wherein the computer storage medium stores a program for audio power amplifier modulation, and when the program for audio power amplifier modulation is executed by a processor, it implements the steps of the audio power amplifier modulation method as described above.

[0023] This application provides an audio power amplifier modulation circuit, which includes a modulation unit, a drive signal generation unit, a power output unit, a low-pass filter unit, a feedback unit, and a selection unit. The modulation output terminal of the modulation unit, the drive signal generation unit, the power output unit, and the low-pass filter unit are connected sequentially. The output terminal of the low-pass filter unit is connected to a load. The output terminal of the power output unit is connected to the input terminal of the feedback unit. The output terminal of the feedback unit is connected to the feedback terminal of the modulation unit. The selection unit is connected to the input terminal of the modulation unit. The power amplifier transistor of the power output unit includes a wide bandgap transistor. A semiconductor transistor; the selection unit is used to select the modulation mode of the modulation unit; the modulation unit is used to receive the signal to be modulated and the feedback signal, and to perform pulse modulation on the signal to be modulated based on the modulation mode and the feedback signal to obtain a pulse modulation signal; the drive signal generation unit is used to determine a drive signal based on the pulse modulation signal; the power output unit is used to amplify the pulse modulation signal based on the drive signal to obtain a power output signal; the low-pass filter unit is used to filter the power output signal to obtain a load drive signal; and the feedback unit is used to determine the feedback signal based on the power output signal.

[0024] The modulation unit receives the signal to be modulated; if an input feedback signal is received, the signal to be modulated is pulse-modulated based on the feedback signal to obtain a pulse-modulated signal, wherein the feedback signal includes the output signal of the feedback unit, and the pulse-modulated signal includes the signal to be modulated after pulse modulation; the driving signal corresponding to the pulse-modulated signal is determined in the driving signal generation unit; the pulse-modulated signal is amplified in the power output unit according to the driving signal to obtain a power output signal; the power output signal is filtered by the low-pass filter unit to obtain a load driving signal, and the load is driven based on the load driving signal. By using a wide bandgap semiconductor transistor as the power transistor, the problem of power consumption and heat generation of the MOS transistor being difficult to control when the modulation frequency is increased to above 500kHz, due to the large junction capacitance of the MOS transistor in the prior art, is avoided. This leads to the need to increase the filter capacitor of the filter circuit and add a heat sink to meet the sound quality requirements. By using a wide bandgap semiconductor transistor, the power consumption and heat generation of the power transistor are effectively suppressed, and the area occupied by the filter capacitor and heat sink can be reduced, thereby realizing the miniaturization of audio power amplifier modulation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application 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 application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structural framework of the audio power amplifier modulation circuit of this application;

[0027] Figure 2 This is a physical diagram showing the connection of the power output unit in the audio power amplifier modulation circuit of this application;

[0028] Figure 3 This is a schematic diagram of the low-pass filter unit in the audio power amplifier modulation circuit of this application.

[0029] Figure 4 This is a schematic diagram of the modulation unit in the audio power amplifier modulation circuit of this application.

[0030] Figure 5 This is a schematic diagram of the audio power amplifier modulation device structure in the hardware operating environment involved in the embodiments of this application;

[0031] Figure 6 This is a flowchart illustrating an embodiment of the audio power amplifier modulation method of this application.

[0032] Explanation of icon numbers:

[0033] 0001 Communication bus 0002 Get Interface 0003 processor 0004 Processing interface 0005 memory 10 Modulation unit 20 Drive signal generation unit 30 Power output unit 40 Low-pass filter unit 50 Feedback Unit 60 load 31 Wide bandgap semiconductor transistors 32 heat sink 33 Heat dissipation material 3A driver level 3B Power output stage 3C Heat dissipation surface 41 Filter inductor 42 Filter capacitor 100 Modulated signal interface 200 Carrier signal interface 11 Adder 12 Pulse modulation circuit 1A Positive input terminal 1B negative input terminal 21 Gate-level drivers 1D Modulation output terminal 70 Select Unit

[0034] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0036] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0037] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions 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, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0038] To ensure clarity and conciseness in the description of the following embodiments, a brief introduction to the implementation of audio power amplifier modulation is given first:

[0039] Traditional Class D audio (digital audio) power amplifiers typically use MOSFETs as their power transistors. The raw audio input is converted into a pulse signal, driving the MOSFET to turn on or off. Compared to linear audio amplifiers (such as Class A, Class B, and Class AB), their power consumption is significantly reduced, and their efficiency can reach 85%-90%. To modulate analog audio below 20kHz into a pulse-modulated signal, the modulation frequency must reach at least 200kHz. Higher pulse modulation frequencies result in better reproduction of the original audio input signal and a smaller amplifier size and weight. Class A refers to a power amplifier circuit where current conducts throughout the entire cycle of the input signal (i.e., the conduction angle is the full cycle). Class B refers to a power amplifier circuit where current conducts for only half a cycle of the input signal (i.e., the conduction angle is half a cycle). Class AB refers to a power amplifier circuit where the current conducts for more than half a cycle but less than one cycle of the input signal (conduction angle between half a cycle and one cycle). However, due to the large junction capacitance of MOSFETs, when the modulation frequency is increased to above 500kHz, the power consumption and heat generation of MOSFETs become difficult to control. This limits the improvement of the sound quality of Class D audio amplifiers and their development towards miniaturization, lightweighting, and portability. An audio power amplifier modulation circuit includes a modulation unit, a drive signal generation unit, a power output unit, a low-pass filter unit, a feedback unit, and a selection unit. The modulation output terminal of the modulation unit, the drive signal generation unit, the power output unit, and the low-pass filter unit are connected sequentially. The output terminal of the low-pass filter unit is connected to a load. The output terminal of the power output unit is connected to the input terminal of the feedback unit. The output terminal of the feedback unit is connected to the feedback terminal of the modulation unit. The selection unit is connected to the input terminal of the modulation unit. The power amplifier transistor of the power output unit includes a wide-bandgap semiconductor transistor. The selection unit is used to select the modulation mode of the modulation unit. The modulation unit is used to receive a signal to be modulated and a feedback signal, and to pulse-modulate the signal to be modulated based on the modulation mode and the feedback signal to obtain a pulse-modulated signal. The drive signal generation unit is used to determine a drive signal based on the pulse-modulated signal. The power output unit is used to amplify the pulse-modulated signal based on the drive signal to obtain a power output signal. The low-pass filter unit is used to filter the power output signal to obtain a load drive signal. The feedback unit is used to determine the feedback signal based on the power output signal. Furthermore, by using wide bandgap semiconductor transistors, the power consumption and heat generation of power transistors are effectively suppressed, which further reduces the area occupied by filter capacitors and heat sinks, thereby realizing the miniaturization of audio power amplifier modulation.

[0040] This application proposes an audio power amplifier modulation circuit.

[0041] In one embodiment of this application, as Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of an audio power amplifier modulation circuit, which includes a modulation unit 10, a drive signal generation unit 20, a power output unit 30, a low-pass filter unit 40, a feedback unit 50, and a selection unit 70.

[0042] The modulation output terminal 1D of the modulation unit 10, the drive signal generation unit 20, the power output unit 30, and the low-pass filter unit 40 are connected in sequence. The output terminal of the low-pass filter unit 40 is connected to the load 60. The output terminal of the power output unit 30 is connected to the input terminal of the feedback unit 50. The output terminal of the feedback unit 50 is connected to the feedback terminal 1C of the modulation unit 10. The selection unit 70 is connected to the input terminal of the modulation unit 10. The power amplifier transistor of the power output unit 30 includes a wide bandgap semiconductor transistor 31.

[0043] The selection unit 70 is used to select the modulation mode of the modulation unit 10. The modulation unit 10 is used to receive the signal to be modulated and the feedback signal, and to perform pulse modulation on the signal to be modulated based on the modulation mode and the feedback signal to obtain a pulse modulation signal. The drive signal generation unit 20 is used to determine a drive signal based on the pulse modulation signal. The power output unit 30 is used to amplify the power of the pulse modulation signal based on the drive signal to obtain a power output signal. The low-pass filter unit 40 is used to filter the power output signal to obtain a load drive signal. The feedback unit 50 is used to determine the feedback signal based on the power output signal.

[0044] In this embodiment, the modulation output terminal 1D of the modulation unit 10, the drive signal generation unit 20, the power output unit 30, the low-pass filter unit 40, and the load 60 are connected in sequence, so that the input signal to be modulated can be output through the above units, and finally achieve the effect of driving the load. The selection unit 70 can be a combination of a switch and a selector. It can be set between the signal interface 100 to be modulated and the positive input terminal 1A, or it can be set before the signal interface 100 to be modulated, or in other positions. Taking the setting between the two as an example. When the switch is pressed, the selector connects the modulation signal interface 100 to the density modulation line in the modulation unit, enabling density modulation of the entire circuit. When the switch is not pressed, the selector connects the modulation signal interface 100 to the width modulation line in the modulation unit, enabling width modulation of the entire circuit. The selection unit 70 can also be based on whether the quantizer is working. If the quantizer is working, the selection unit determines whether the modulation signal interface 100 and the width modulation line in the modulation unit are connected; otherwise, if the quantizer is not working, the selection unit determines whether the selection unit is connected. Other working principles and selection methods are also possible. The output of the feedback unit 50 is connected to the feedback terminal 1C of the modulation unit 10, and the output of the power output unit 30 is connected to the input of the feedback unit 50. This allows for feedback adjustment of the modulation signal each time, greatly improving the accuracy of the entire signal. When the signal is initially input, the modulation unit 10 receives the signal to be modulated and proceeds to subsequent steps. When the signal is not initially input, the modulation unit 10 receives the signal to be modulated and the feedback signal and proceeds to subsequent steps. The feedback signal refers to the signal corrected by the feedback unit 50 based on the modulated output signal. The feedback unit 50 can be connected to the output of any unit, but the judgment and correction criteria differ. In this embodiment, connecting it to the output of the power output unit 30 yields the best results. The width modulation can use the same circuit as existing width modulation circuits and is not limited here. Pulse modulation modulates the duty cycle or density of the signal in the modulated signal; therefore, the pulse modulation method here can be density modulation or width modulation. The signal to be modulated refers to the signal that needs to be modulated, which can be an analog audio signal or a PCM (Pulse-code modulation) digital audio signal. The signal to be modulated can then be modulated using PWM (pulse width modulation), PDM (pulse density modulation), or other modulation methods based on the feedback signal to obtain a pulse-modulated signal.The pulse modulation frequency range is above 500kHz. Because the power amplifier transistors used are wide-bandgap semiconductor transistors, there will be no uncontrollable power consumption or heat generation issues above 500kHz. The modulated pulse signal is output to the drive signal generation unit 20. The pulse modulation signal refers to the signal after pulse modulation, i.e., the pulse modulation signal mentioned later. Then, the drive signal generation unit 20 receives the pulse modulation signal output from the modulation unit 10 and generates a drive signal to drive the power amplifier transistor in the next stage power output unit 30 to turn on or off. The drive signal is the signal that determines whether the power amplifier transistor is turned on or off. It can be simply controlled so that when the pulse modulation signal is received, the drive signal turns on the power amplifier transistor; when the pulse modulation signal is not received, the drive signal turns off the power amplifier transistor. Finally, the drive signal is sent to the power output unit 30.

[0045] The power amplifier transistor in the power output unit 30 is a wide-bandgap semiconductor transistor 31. After receiving the drive signal, the wide-bandgap semiconductor transistor 31 amplifies the pulse modulation signal to obtain the power output signal. The power output signal refers to the pulse modulation signal amplified by the wide-bandgap semiconductor transistor 31. Finally, the power output signal is filtered out by the low-pass filter unit 40 to remove high-frequency components, extracting the amplified analog or digital audio signal as the load drive signal, which then drives the load. The load drive signal refers to the power output signal after removing high-frequency components. Simultaneously, the feedback unit 50 detects the power output signal and feeds back the corresponding feedback information to the feedback terminal 1C of the modulation unit 10. A closed-loop control loop corrects the output, maintaining the linearity of the power amplifier output and ensuring the accuracy of the entire modulation signal.

[0046] This embodiment uses a wide-bandgap semiconductor transistor 31, avoiding the power consumption and heat generation issues associated with using MOSFETs. This allows the modulation frequency of the modulation unit 10 to be increased to over 500kHz. Therefore, the modulated pulse signal better reproduces the original input audio signal, reducing audio distortion and achieving better output sound quality, thus realizing the high-fidelity characteristics of the power amplifier. Simultaneously, the increased modulation frequency reduces the energy stored in the inductor and capacitor of the low-pass filter unit 40 during each switching cycle, thereby reducing the size requirements of the low-pass filter unit 40 and decreasing the size and weight of the power amplifier. Secondly, to accommodate the increased transistor power consumption and the need for a larger heatsink due to the increased modulation frequency, the power output stage of this embodiment uses a wide-bandgap semiconductor transistor with low gate drive voltage, small junction capacitance, and low on-resistance. The low gate drive voltage and small junction capacitance allow the transistor to turn on or off in a shorter time, thus meeting the modulation frequency of over 500kHz for the pulse modulation unit. The switching frequency of silicon carbide transistors can reach 1MHz, while the switching frequency of gallium nitride transistors can even reach 10MHz. Meanwhile, the smaller junction capacitance and lower on-resistance can also greatly reduce the conduction loss of the transistor, achieving high efficiency and low heat dissipation while maintaining a high switching frequency. This allows for a further reduction in the size of the heat sink, enabling the miniaturization, lightweighting, and portability of Class D audio power amplifiers.

[0047] In short, this embodiment increases the pulse width modulation frequency of the power amplifier to over 500kHz through the audio power amplifier modulation circuit. By utilizing the characteristics of low gate drive voltage, small junction capacitance, and low on-resistance of the wide bandgap semiconductor transistors in the power output stage, while maintaining high efficiency and low distortion of the power amplifier, the size of the capacitors and inductors in the low-pass filter unit and the size of the power transistor heat sink are reduced. This further reduces the size and weight of the audio power amplifier modulation circuit, realizing the design of a high-fidelity, miniaturized, lightweight, and portable audio power amplifier. This not only provides users with a better experience but also reduces equipment costs, and has broad market prospects.

[0048] Furthermore, in another embodiment of the audio power amplifier modulation circuit of this application, referring to... Figure 2 , Figure 2This is a physical diagram showing the connection of the power output unit in an audio power amplifier modulation circuit. The power output unit 30 includes a wide bandgap semiconductor transistor 31 and a heat sink 32. The driver stage 3A of the wide bandgap semiconductor transistor 31 is connected to the drive signal generation unit 20, and the power output stage 3B of the wide bandgap semiconductor transistor 31 is connected to the input terminal of the low-pass filter unit 40. A heat dissipation material 33 is disposed on the heat dissipation surface 3C of the wide bandgap semiconductor transistor 31, wherein the heat dissipation material 33 includes thermally conductive silicone or thermally conductive grease. The wide bandgap semiconductor transistor 31 is used to receive the drive signal sent by the drive signal generation unit and amplify the pulse modulation signal based on the drive signal to obtain a power output signal.

[0049] Specifically, the wide bandgap semiconductor transistor 31 includes a gallium nitride transistor or a silicon carbide transistor.

[0050] In this embodiment, refer to Figure 2 In Figure (a), the power output unit 30 consists of at least a wide-bandgap semiconductor transistor 31 and its heat sink 32. The wide-bandgap semiconductor transistor 31 includes, but is not limited to, gallium nitride and silicon carbide transistors. The driver stage 3A composed of the wide-bandgap semiconductor transistor 31 can be either a half-bridge or a full-bridge, and the rail voltage (i.e., the driver stage drive voltage) can be either a single power supply or a positive and negative power supply. The wide-bandgap semiconductor transistor 31 receives the drive signal sent by the drive signal generation unit and amplifies the pulse modulation signal based on the drive signal to obtain the power output signal. (Refer to...) Figure 2 In Figure (b), the main function of the heat sink 32 is to dissipate heat from the wide-bandgap semiconductor transistor 31. The heat sink 32 is placed in contact with the heat sink 32 after the heat dissipation surface 3C of the wide-bandgap semiconductor transistor 31 is coated with heat dissipation material 33, thereby achieving the effect of heat dissipation for the wide-bandgap semiconductor transistor 31. The heat dissipation surface 3C of the wide-bandgap semiconductor transistor 31, the heat sink 32, and the heat dissipation material 33 can also be of the same size, or have other size relationships. The heat dissipation material 33 includes, but is not limited to, thermally conductive silicone or thermal grease, ultimately achieving heat dissipation for the wide-bandgap semiconductor transistor 31.

[0051] In one embodiment of this application, the drive signal generation unit 20 includes a gate driver 21. The input terminal of the gate driver 21 is connected to the modulation output terminal 1D of the modulation unit 10, and the output terminal of the gate driver 21 is connected to the drive stage 3A of the wide bandgap semiconductor transistor 31. The gate driver 21 is used to determine the drive signal according to the pulse modulation signal.

[0052] In this embodiment, the drive signal generation unit 20 includes at least a gate driver 21, and may also include other electrical components or parts. Its main function is to receive pulse modulation signals by connecting the input terminal of the gate driver 21 to the modulation output terminal 1D of the modulation unit 10. After processing by the gate driver 21, a drive signal is obtained. This signal is then output through the output terminal of the gate driver 21 to the drive stage 3A of the wide bandgap semiconductor transistor 31 to control the on / off state of the wide bandgap semiconductor transistor 31. This achieves the effect of saving control voltage and prevents the wide bandgap semiconductor transistor 31 from being constantly on, thereby reducing its lifespan and improving the control accuracy of the wide bandgap semiconductor transistor 31.

[0053] In one embodiment of this application, as Figure 3 As shown, Figure 3 This is a schematic diagram of the low-pass filter unit in the modulation circuit of an audio power amplifier. The low-pass filter unit 40 includes at least one filter inductor 41 and at least one filter capacitor 42. The first end of the filter inductor 41 is connected to the power output stage 3B of the wide bandgap semiconductor transistor 31. The second end of the filter inductor 41 is connected to the first end of the filter capacitor 42 and the load 60, respectively. The second end of the filter capacitor 42 is grounded. The low-pass filter unit 40 is used to filter out high-frequency components in the power output signal to obtain the load drive signal.

[0054] In this embodiment, the low-pass filter unit 40 includes at least one filter inductor 41 and at least one filter capacitor 42, thereby forming a low-pass filter. The low-pass filter used here can be composed of capacitors and inductors, or other filter components. The low-pass filter composed of the filter inductor 41 and filter capacitor 42 can be a first-order low-pass filter consisting of only a single filter inductor 41 and filter capacitor 42, or a multi-order low-pass filter consisting of multiple filter inductors 41 and filter capacitors 42; this is not limited here. Ultimately, the filter in the low-pass filter unit 40 can filter out high-frequency components in the signal to obtain a load drive signal, thereby driving the load to play lossless audio.

[0055] In yet another embodiment, reference is made to... Figure 4 , Figure 4This is a schematic diagram of the modulation unit in the modulation circuit of an audio power amplifier. The modulation unit 10 includes an adder 11 and a pulse modulation circuit 12. The pulse modulation circuit 12 includes a positive input terminal 1A, a negative input terminal 1B, and a modulation output terminal 1D. The first terminal of the adder 11 is connected to the interface 100 of the signal to be modulated, the second terminal of the adder 11 is connected to the output terminal of the feedback unit 50, the output terminal of the adder 11 is connected to the positive input terminal 1A, the negative input terminal 1B is connected to the carrier signal interface 200, and the modulation output terminal 1D is connected to the input terminal of the gate driver 21.

[0056] In this embodiment, when the modulation unit 10 modulates the input signal to be modulated, it refers to... Figure 4 As shown in Figure (a), the input signal terminal can be connected to the modulated signal interface 100 via adder 11, and the negative input terminal 1B can be connected to the carrier signal interface 200. The modulated signal interface 100 refers to the interface for receiving the signal to be modulated, and the carrier signal interface 200 refers to the interface for receiving the carrier signal. After the signals to be modulated are added in the same direction or subtracted in opposite directions, they are connected to the positive input terminal 1A of the pulse modulation circuit 12 for modulation. The output terminal of the feedback unit 50 is connected and connected to the feedback signal. Finally, the modulated signal is output through the modulation output terminal 1D to the input terminal of the gate driver 21, so that the gate driver 21 generates a drive signal. The pulse modulation circuit 12 refers to a large pulse modulation circuit, which may contain different devices. The specific pulse modulation method is consistent with existing pulse modulation methods (pulse modulation includes at least density modulation and width modulation), and is not limited here. See also... Figure 4 As shown in Figure (b), the input signal terminal can be directly connected to the positive input terminal 1A and the negative input terminal 1B of the pulse modulation circuit 12, thereby achieving the effect of subtracting the carrier signal from the signal to be modulated. The above circuit can perform pulse modulation on the signal to be modulated, and the modulation frequency can be above 500kHz, thus ensuring the restoration effect of the original input signal and improving the accuracy of signal processing.

[0057] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0058] Reference Figure 5 , Figure 5 This is a schematic diagram of the audio power amplifier modulation device structure in the hardware operating environment involved in the embodiments of this application.

[0059] like Figure 5As shown, the audio power amplifier modulation device may include: a processor 0003, such as a central processing unit (CPU), a communication bus 0001, an acquisition interface 0002, a processing interface 0004, and a memory 0005. The communication bus 0001 is used to establish communication between these components. The acquisition interface 0002 may include an information acquisition device or acquisition unit, such as a computer; optionally, the acquisition interface 0002 may also include a standard wired interface or a wireless interface. The processing interface 0004 may optionally include a standard wired interface or a wireless interface. The memory 0005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 0005 may also be a storage device independent of the aforementioned processor 0003.

[0060] Those skilled in the art will understand that Figure 5 The structure shown does not constitute a limitation on audio power amplifier modulation equipment, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0061] like Figure 5 As shown, the memory 0005, which is a computer storage medium, may include an operating system, an acquisition interface module, a processing interface module, and an audio power amplifier modulation program.

[0062] exist Figure 5 In the audio power amplifier modulation device shown, the communication bus 0001 is mainly used to realize the connection and communication between components; the acquisition interface 0002 is mainly used to connect to the backend server and communicate data with the backend server; the processing interface 0004 is mainly used to connect to the deployment end (user end) and communicate data with the deployment end; the processor 0003 and the memory 0005 in the audio power amplifier modulation device of this application can be set in the audio power amplifier modulation device. The audio power amplifier modulation device calls the audio power amplifier modulation program stored in the memory 0005 through the processor 0003 and executes the audio power amplifier modulation method provided in the embodiment of this application.

[0063] Based on the above hardware structure, an embodiment of the audio power amplifier modulation method of this application is proposed.

[0064] Furthermore, based on an embodiment of the above-described audio power amplifier modulation circuit, an embodiment of the audio power amplifier modulation method of this application is proposed.

[0065] For reference Figure 6 , Figure 6 This is a schematic flowchart illustrating an embodiment of the audio power amplifier modulation method of this application. Figure 6 As shown, the steps of the audio power amplifier modulation method of this application include:

[0066] Step S10: Receive the signal to be modulated through the modulation unit;

[0067] Step S20: If an input feedback signal is received, the signal to be modulated is pulse modulated based on the feedback signal to obtain a pulse modulated signal, wherein the feedback signal includes the output signal of the feedback unit, and the pulse modulated signal includes the signal to be modulated after pulse modulation.

[0068] In this embodiment, after the modulation unit receives the signal to be modulated, it checks whether an input feedback signal has been received. If no input feedback signal is received, modulation is performed directly based on the signal to be modulated. The feedback signal refers to the signal that the feedback unit corrects based on the modulated output signal, and the signal to be modulated is the signal that needs to be modulated. Alternatively, detection can be performed within the modulation unit. By detecting the signal characteristics of the signal to be modulated, it can be determined whether the signal characteristics repeat within a preset time. If they repeat, a feedback signal is detected, and a attention instruction is generated; otherwise, modulation is performed directly based on the signal to be modulated. Here, signal characteristics refer to unique signal features of the signal to be modulated, and the preset time refers to a preset time range. This detection determines whether it is the initial input signal to be modulated, and the time range prevents identical feedback information from the same signal to be modulated with large time intervals. When an input feedback signal is received, it indicates that it is not the initially input signal to be modulated, and feedback adjustment is required. The feedback unit receives the power output signal, or signals from other output locations for processing; this is not limited here. A fixed gain is applied to the power output signal, and a feedback value proportional to the power output signal is output. Here, signal gain refers to the gain of the signal after density modulation, and preset signal gain refers to the gain of the signal that meets the modulation requirements or is a custom signal. In short, feedback ensures the accuracy of the entire modulated signal output. When the signal gain is within the preset signal gain range, the step of receiving the power output signal through the feedback unit continues, meaning the modulation meets the requirements. When the signal gain is outside the preset signal gain range, a corresponding feedback value is determined through a preset mapping table. This feedback value is then used as a feedback signal and transmitted to the modulation unit. Finally, the modulation unit modulates the newly received signal based on the feedback signal. The mapping table refers to the mapping relationship between duty cycle and feedback value, and the feedback value is a numerical value. For example, if the signal gain is 'a' and the preset signal gain range is (b, c), and 'a' is not within (b, c), then 'a' corresponds to the feedback value 'd' in the preset mapping table. Finally, the newly received signal is modulated based on the feedback value 'd' to achieve a new signal gain 'e', ​​which is within or infinitely close to the preset signal gain range (b, c). Whether modulation is performed in the latter case depends on actual needs. Before modulating the newly received signal based on the feedback value d, it is determined whether the newly received signal is the same as the previously received signal. If so, modulation of the newly received signal based on the feedback value d is performed; otherwise, modulation is performed directly. The feedback unit detects the power output signal and feeds its corresponding feedback information back to the modulation unit, enabling it to correct the output through a closed-loop control loop, maintaining the linearity of the power amplifier output, and thus ensuring the accuracy of the entire modulated signal.The feedback signal is the output signal of the feedback unit, and the pulse modulation signal is the signal after pulse modulation. Ultimately, the modulation unit modulates the signal to be modulated, thus providing a basis for subsequent processing.

[0069] Step S30: Determine the driving signal corresponding to the pulse modulation signal in the driving signal generation unit;

[0070] Step S40: According to the driving signal, the pulse modulation signal is amplified in the power output unit to obtain a power output signal;

[0071] Step S50: The power output signal is filtered by the low-pass filter unit to obtain the load drive signal, and the load is driven based on the load drive signal.

[0072] In this embodiment, after obtaining the pulse modulation signal, a corresponding drive signal is determined in the drive signal generation unit based on the pulse modulation signal. Finally, the wide-bandgap semiconductor transistor in the power output unit is driven by the drive signal to amplify the pulse modulation signal and obtain a power output signal. Here, the drive signal is the signal that determines whether the power amplifier transistor is turned on or off, and the power output signal is the pulse modulation signal after power amplification by the wide-bandgap semiconductor transistor. Finally, the power output signal is filtered by a low-pass filter unit to remove high-frequency components, resulting in a load drive signal to drive the load. Here, the load drive signal is the power output signal after removing high-frequency components. After the step of receiving the signal to be modulated by the modulation unit, the following steps are included:

[0073] Step S11: Receive a carrier signal through the pulse modulation circuit in the modulation unit, and perform pulse modulation on the signal to be modulated based on the carrier signal to obtain a pulse modulated signal.

[0074] In this embodiment, the pulse modulation includes at least pulse density modulation and pulse width modulation. Pulse width modulation mainly involves pulse modulation of the signal to be modulated based on the carrier signal received by the pulse modulation circuit. Pulse width modulation refers to the modulation and comparison of two signals, where the carrier signal can be a fixed-frequency carrier (triangular wave or sawtooth wave). Pulse density modulation refers to the process where, before pulse modulation of the carrier signal, the signal to be modulated is quantized and shaped by the quantizer in the pulse density modulation circuit, and then density modulation is performed on the quantized and shaped signal to obtain the pulse modulated signal. This can also be adaptively selected according to actual needs. The duty cycle of the final pulse modulated signal is proportional to the amplitude of the signal to be modulated. Pulse modulation of the signal to be modulated is achieved through the modulation unit, thus providing a processing basis for subsequent signal processing. Alternatively, the density of the final pulse modulated signal is proportional to the amplitude of the signal to be modulated, and density modulation of the signal to be modulated is achieved through the pulse density modulation unit, thus providing a processing basis for subsequent signal processing.

[0075] This application also provides an audio power amplifier modulation device.

[0076] The device of this application includes: a memory, a processor, an audio power amplifier modulation circuit in the audio power amplifier modulation method, and an audio power amplifier modulation program stored in the memory and executable on the processor. When the audio power amplifier modulation program is executed by the processor, it implements the steps of the audio power amplifier modulation method as described above.

[0077] This application also provides a computer storage medium.

[0078] The computer storage medium of this application stores a program for audio power amplifier modulation, which, when executed by a processor, implements the steps of the audio power amplifier modulation method described above.

[0079] The method implemented when the audio power amplifier modulation program running on the processor is executed can be referred to in various embodiments of the audio power amplifier modulation method of this application, and will not be repeated here.

[0080] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0081] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0082] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. An audio power amplifier modulation circuit, characterized in that, The audio power amplifier modulation circuit includes a modulation unit, a drive signal generation unit, a power output unit, a low-pass filter unit, a feedback unit, and a selection unit; The modulation output terminal of the modulation unit, the drive signal generation unit, the power output unit, and the low-pass filter unit are connected in sequence. The output terminal of the low-pass filter unit is connected to the load. The output terminal of the power output unit is connected to the input terminal of the feedback unit. The output terminal of the feedback unit is connected to the feedback terminal of the modulation unit. The selection unit is connected to the input terminal of the modulation unit. The power amplifier transistor of the power output unit includes a wide bandgap semiconductor transistor. The selection unit is used to select the modulation mode of the modulation unit. The modulation unit is used to receive the signal to be modulated and the feedback signal, and to perform pulse modulation on the signal to be modulated based on the modulation mode and the feedback signal to obtain a pulse modulation signal. The drive signal generation unit is used to determine a drive signal based on the pulse modulation signal. The power output unit is used to amplify the pulse modulation signal based on the drive signal to obtain a power output signal. The low-pass filter unit is used to filter the power output signal to obtain a load drive signal. The feedback unit is used to determine the feedback signal based on the power output signal. The power output unit includes a wide bandgap semiconductor transistor and a heat sink. The drive stage of the wide bandgap semiconductor transistor is connected to the drive signal generation unit. The power output stage of the wide bandgap semiconductor transistor is connected to the input terminal of the low-pass filter unit. The drive signal generation unit includes a gate driver. The input terminal of the gate driver is connected to the modulation output terminal of the modulation unit. The output terminal of the gate driver is connected to the drive stage of the wide bandgap semiconductor transistor. The gate driver is used to determine the drive signal based on the pulse modulation signal.

2. The audio power amplifier modulation circuit as described in claim 1, characterized in that, The heat sink is provided with heat dissipation material, and one end of the heat dissipation material is disposed on the heat dissipation surface of the wide bandgap semiconductor transistor. The heat dissipation material includes thermally conductive silicone or thermally conductive grease. The wide bandgap semiconductor transistor is used to receive the drive signal sent by the drive signal generation unit and to amplify the pulse modulation signal based on the drive signal to obtain a power output signal.

3. The audio power amplifier modulation circuit as described in claim 2, characterized in that, The wide bandgap semiconductor transistor includes a gallium nitride transistor or a silicon carbide transistor.

4. The audio power amplifier modulation circuit as described in claim 1, characterized in that, The low-pass filter unit includes at least one filter inductor and at least one filter capacitor. The first end of the filter inductor is connected to the power output stage of the wide bandgap semiconductor transistor. The second end of the filter inductor is connected to the first end of the filter capacitor and the load, respectively. The second end of the filter capacitor is grounded. The low-pass filter unit is used to filter out high-frequency components in the power output signal to obtain the load drive signal.

5. The audio power amplifier modulation circuit as described in any one of claims 1-4, characterized in that, The modulation unit includes an adder and a pulse modulation circuit. The pulse modulation circuit includes a positive input terminal, a negative input terminal, and a modulation output terminal. The first terminal of the adder is connected to the interface of the signal to be modulated, the second terminal of the adder is connected to the output terminal of the feedback unit, the output terminal of the adder is connected to the positive input terminal, the negative input terminal is connected to the carrier signal interface, and the modulation output terminal is connected to the input terminal of the gate driver.

6. An audio power amplifier modulation method, characterized in that, The audio power amplifier modulation method is applied to the audio power amplifier modulation circuit according to any one of claims 1 to 5, and the steps of the audio power amplifier modulation method include: The signal to be modulated is received through the modulation unit; If an input feedback signal is received, the signal to be modulated is pulse modulated based on the feedback signal to obtain a pulse modulated signal, wherein the feedback signal includes the output signal of the feedback unit, and the pulse modulated signal includes the signal to be modulated after pulse modulation; The driving signal corresponding to the pulse modulation signal is determined in the driving signal generation unit; The power output signal is obtained by amplifying the pulse modulation signal in the power output unit according to the driving signal. The power output signal is filtered by the low-pass filter unit to obtain the load drive signal, and the load is driven based on the load drive signal.

7. The audio power amplifier modulation method as described in claim 6, characterized in that, After the step of receiving the signal to be modulated through the modulation unit, the following steps are included: The modulation unit receives a carrier signal through a pulse modulation circuit and performs pulse modulation on the signal to be modulated based on the carrier signal to obtain a pulse modulated signal.

8. An audio power amplifier modulation device, characterized in that, The audio power amplifier modulation device includes: a memory, a processor, and an audio power amplifier modulation program stored in the memory and executable on the processor. When the audio power amplifier modulation program is executed by the processor, it implements the steps of the audio power amplifier modulation method as described in any one of claims 6 to 7.

9. A computer storage medium, characterized in that, The computer storage medium stores an audio power amplifier modulation program, which, when executed by a processor, implements the steps of the audio power amplifier modulation method as described in any one of claims 6 to 7.

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