Audio amplifier and driving control method therefor and related apparatus

Abstract

This application discloses an audio amplifier, its driving control method, and related apparatus. The audio amplifier includes an audio amplifier chip, a filter, and a load. The audio amplifier chip is connected to a first terminal of the filter via an output port. The second terminal of the filter is grounded, and the third terminal of the filter is connected to one end of the load, while the other end of the load is grounded. Using the audio amplifier in this application can save on filter component costs. Furthermore, the duty cycle of the pulse width modulation signal used to drive the load is small in the static state, thereby reducing the current flowing through each filter and thus reducing static power consumption.

Description

Technical Field

[0001] This invention relates to the field of amplifier technology, and in particular to an audio amplifier, its driving control method, and related devices. Background Technology

[0002] An audio amplifier is an electronic device or circuit whose main function is to amplify weak audio signals (such as those from microphones, mobile phones, music players, etc.) to a sufficiently strong level to drive speakers, headphones, or other audio output devices, thereby producing audible sound.

[0003] Audio amplifiers are widely used in car audio systems, and multi-channel designs can enhance sound quality and immersion. For example, economy cars typically use four-channel or six-channel systems, with each channel driving one or two speakers to meet basic listening needs. Some mid-range models add a center speaker or subwoofer, often using six-channel or eight-channel systems to support richer sound effects and a surround sound experience. High-end models are equipped with multi-channel systems, such as those from brands like Bose and Harman Kardon, supporting advanced sound effects like 7.1.4 Dolby Atmos to provide an immersive listening experience. Luxury flagship models use multi-channel systems with more than 20 speakers, supporting complex channel layouts to create an ultimate surround sound field.

[0004] With the development of car audio technology and the increasing demands of consumers for sound quality, from economy cars to luxury flagship models, there is a growing pursuit of more and more speakers. If traditional audio amplifiers are used, it will lead to a significant increase in component costs and static power consumption. Summary of the Invention

[0005] This application provides an audio amplifier, its driving control method, and related apparatus, which can maintain or reduce device cost and static power consumption while increasing the number of channels.

[0006] The first aspect of this application provides an audio amplifier, which includes an audio amplifier chip, a filter, and a load; the audio amplifier chip is connected to a first end of the filter through an output port, a second end of the filter is grounded, a third end of the filter is connected to one end of the load, and the other end of the load is grounded.

[0007] Optionally, the audio amplifier chip includes a half-bridge circuit, each half-bridge circuit corresponding to one output port. The half-bridge circuit consists of two switching transistors connected in series, the input terminal of one of the switching transistors is connected to a positive power supply, the output terminal of one of the switching transistors is connected to the input terminal of the other switching transistor, and the output terminal of the other switching transistor is connected to a negative power supply.

[0008] Optionally, the output voltage of the negative power supply is obtained by converting the output voltage of the positive power supply through a DC-to-DC circuit.

[0009] Optionally, the audio amplifier chip further includes a gate driving unit, each gate driving unit corresponding to one half-bridge circuit. The gate driving unit is used to compare the amplified signal with a preset modulation signal and output a pulse width modulation signal. The pulse width modulation signal is used to alternately drive the gates of the two switching transistors so that current flows through the load. The amplified signal is obtained by conversion based on the input audio signal.

[0010] Optionally, if the amplitude of the output signal of the audio amplifier chip is less than a preset amplitude threshold, the positive power supply is powered by a first fixed battery voltage, and the negative power supply is powered by a second fixed battery voltage, wherein the amplitude of the first fixed battery voltage is greater than the amplitude of the second fixed battery voltage. If the amplitude of the output signal of the audio amplifier chip is greater than or equal to the preset amplitude threshold and less than the amplitude of the battery voltage, then the positive power supply is powered by the first fixed battery voltage, and the negative power supply is powered by the first variable battery voltage that varies with the output signal of the audio amplifier chip. If the amplitude of the output signal of the audio amplifier chip is greater than or equal to the amplitude of the battery voltage, the positive power supply is powered by a second variable battery voltage that varies with the output signal of the audio amplifier chip; the negative power supply is powered by a third variable battery voltage that varies in the opposite direction with the output signal of the audio amplifier chip.

[0011] Optionally, the duty cycle of the pulse width modulation signal is determined based on the supply voltage of the positive power supply, the supply voltage of the negative battery, the voltage corresponding to the output signal of the audio amplifier chip, and a duty cycle determination formula. The duty cycle determination formula is as follows: , in, For PWM duty cycle, The supply voltage used by the positive power source includes the first fixed battery voltage and the second variable battery voltage. The supply voltage used by the negative power source includes the second fixed battery voltage, the first variable battery voltage, and the third variable battery voltage. This refers to the voltage corresponding to the output signal of the audio amplifier chip.

[0012] A second aspect of this application provides an audio amplifier driving control method, applied to the audio amplifier in the first aspect of this application, the method comprising: The amplified signal is obtained by converting the input audio signal; The amplified signal is compared with a preset modulation signal to obtain a pulse width modulation signal; The duty cycle of the pulse width modulation signal is determined by the supply voltage of the positive power supply, the supply voltage of the negative battery, and the voltage corresponding to the output signal of the audio amplifier chip. The pulse width modulation signal having the duty cycle is applied to the gate of the switching transistor so that current flows through the load.

[0013] A third aspect of this application provides an audio amplifier drive control device, applied to the audio amplifier in the first aspect of this application, the device comprising: The signal amplification unit is used to convert the input audio signal into an amplified signal. A pulse width modulation signal generation unit is used to compare the amplified signal with a preset modulation signal to obtain a pulse width modulation signal; The duty cycle determination unit is used to determine the duty cycle of the pulse width modulation signal by taking the supply voltage of the positive power supply, the supply voltage of the negative battery, and the voltage corresponding to the output signal of the audio amplifier chip. A drive control unit is configured to apply the pulse width modulation signal having the duty cycle to the gate of the switching transistor so that current flows through the load.

[0014] A fourth aspect of this application provides an electronic device, including: a processor and a memory; The processor is connected to a memory, wherein the memory is used to store computer programs and the processor is used to invoke the computer programs to execute the methods as described in the second aspect of the embodiments of this application.

[0015] The fifth aspect of this application provides a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, perform the method as described in the second aspect of this application.

[0016] The audio amplifier provided in this application includes an audio amplifier chip, a filter, and a load. The audio amplifier chip is connected to a first terminal of the filter via an output port, the second terminal of the filter is grounded, the third terminal of the filter is connected to one end of the load, and the other end of the load is grounded. Using the audio amplifier in this application can save on filter component costs. Furthermore, the duty cycle of the pulse width modulation signal used to drive the load is small in the static state, thereby reducing the current flowing through each filter and thus reducing static power consumption. Attached Figure Description

[0017] 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a two-channel audio amplifier with a single-ended load in the prior art is shown. Figure 2 A schematic diagram of a two-channel audio amplifier with a bridged load in the prior art is shown. Figure 3 A schematic diagram of a four-channel audio amplifier with a parallel bridged load in the prior art is shown. Figure 4 This paper shows a schematic diagram of the structure of a single-channel audio amplifier provided in an embodiment of this application; Figure 5 A schematic diagram of another single-channel audio amplifier provided in an embodiment of this application is shown; Figure 6 This paper shows a schematic diagram of the structure of a two-channel audio amplifier provided in an embodiment of this application; Figure 7 A schematic diagram of another two-channel audio amplifier provided in an embodiment of this application is shown; Figure 8 This illustration shows a schematic diagram of the positive and negative power supply voltage variations of an audio amplifier provided in an embodiment of this application. Figure 9 The diagram illustrates the amplitude variation of the inductor current when the PWM duty cycle is 12.5% ​​and 50% according to the embodiments of this application. Figure 10 A flowchart illustrating an embodiment of the audio amplifier drive control method provided in this application is shown. Figure 11 This invention provides a schematic diagram of the structure of an audio amplifier drive control device according to an embodiment of the present application. Figure 12 A schematic diagram of the structure of a computer device provided in one embodiment of this application is shown. Detailed Implementation

[0019] 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 some embodiments of this application, and not all 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.

[0020] Please refer to Figure 1 This diagram illustrates the structure of a two-channel audio amplifier with a single-ended load in the prior art. The single-ended (SE) load audio amplifier includes an audio amplifier chip, two filters, and two loads. The first filter includes an inductor. ,capacitance and The second filter includes an inductor. ,capacitance and .in: The audio amplifier chip connects to the output port OUT A of one of its channels. One end is connected, The other end is respectively with and One end is connected, The other end is connected to one end of the first load. The other end of the load is grounded, and the other end of the first load is also grounded.

[0021] The audio amplifier chip connects to the output port OUT B of another channel. One end is connected, The other end is respectively with and One end is connected, The other end is connected to one end of the second load. The other end of the load is grounded, and the other end of the second load is also grounded.

[0022] Please refer to Figure 2 This diagram illustrates the structure of a two-channel audio amplifier with a bridged load in the prior art. The bridged load (BTL) audio amplifier includes an audio amplifier chip, two filters, and a load. The first filter includes an inductor. and capacitor The second filter includes an inductor. and capacitor .in: The audio amplifier chip connects to the output port OUT A of one of its channels. One end is connected, The other end is respectively with Connected to one end of the first load. The other end is grounded.

[0023] The audio amplifier chip connects to the output port OUT B of another channel. One end is connected, The other end is respectively with One end is connected to the other end of the first load. The other end is grounded.

[0024] In a BTL (Blocked Through-The-Load) structure, each end of the load is connected to an output port, instead of grounding one end. The signals output from the two ports are out of phase (180° out of phase), therefore the voltage difference across the load is twice that of a single-ended structure, theoretically increasing the output power by up to four times. The BTL structure has two operating modes: Bipolar Differential Mode (BD) and Single-Supply Pulse Width Modulation (1SPW). Specifically: In BD mode, both half-bridges (the left and right arms of the H-bridge) undergo independent PWM modulation. The input audio signal is modulated into two complementary PWM signals: a positive phase signal modulates the left half-bridge (OUT+). Inverting signal → modulates the right half-bridge (OUT) Both PWM waveforms are bipolar modulated (i.e., the duty cycle varies around 50%). Because the two outputs are symmetrical, the common-mode currents on the power supply and ground cancel each other out. Especially in high-frequency switching, the differential structure helps suppress radiation. More complex modulation logic and dead-time control are required.

[0025] In 1SPW mode, only one signal is PWM modulated (usually a positive-phase signal), while the other signal is directly inverted (not remodulated). Therefore, the two signals are strictly complementary, but modulation occurs only once. The circuit is simple and low-cost, requiring only one modulator, simplifying the control logic. The switching node voltage swing is fixed to the supply voltage, which is beneficial for MOSFET driver design. Because the two signals are not independently modulated, the supply current fluctuates significantly, potentially causing greater electromagnetic interference. In silent or zero-input mode, both outputs are 50% duty cycle square waves, still exhibiting high-frequency switching losses.

[0026] Please refer to Figure 3 This diagram illustrates the structure of a four-channel audio amplifier with a parallel bridge-tied load (PBTL) in the prior art. The PBTL audio amplifier includes an audio amplifier chip, two filters, and a load. The first filter includes an inductor. and capacitor The second filter includes an inductor. and capacitor .in: The audio amplifier chip connects to the output port OUT A of the first channel. One end of the channel is connected to the output port OUT C of the third channel. The other end is respectively with Connected to one end of the first load. The other end is grounded.

[0027] The audio amplifier chip connects to the fourth channel output port OUT D. One end is connected to the output port OUT B of the second channel. The other end is respectively with One end is connected to the other end of the first load. The other end is grounded.

[0028] A parallel bridged load (PBTL) connects the outputs in parallel to form a single mono channel. The input signal applied to the same speaker is inverted. Although the maximum output voltage amplitude is the same at both outputs, the maximum current is doubled because each output shares the load current. In other words, a PBTL doubles the current-limiting point of the audio power amplifier by connecting two half-bridges in parallel compared to a BTL. Compared to BTL, a PBTL can output higher power when the load speaker impedance is lower, under the same supply voltage.

[0029] This application provides an audio amplifier, which includes an audio amplifier chip, a filter, and a load. The audio amplifier chip is connected to a first end of the filter through an output port, the second end of the filter is grounded, the third end of the filter is connected to one end of the load, and the other end of the load is grounded.

[0030] The audio amplifier chip includes a half-bridge circuit, each half-bridge circuit corresponding to one output port. The half-bridge circuit is composed of two switching transistors connected in series. The input terminal of one of the switching transistors is connected to the positive power supply, the output terminal of one of the switching transistors is connected to the input terminal of the other switching transistor, and the output terminal of the other switching transistor is connected to the negative power supply.

[0031] The output voltage of the negative power supply is obtained by converting the output voltage of the positive power supply through a DC-to-DC circuit.

[0032] The audio amplifier chip further includes a gate driving unit, each gate driving unit corresponding to one half-bridge circuit. The gate driving unit is used to compare the amplified signal with a preset modulation signal and output a pulse width modulation signal. The pulse width modulation signal is used to alternately drive the gates of the two switching transistors so that current flows through the load. The amplified signal is obtained by conversion based on the input audio signal.

[0033] In this application, the audio amplifier can be single-channel or multi-channel. For a single-channel embodiment, please refer to [link to relevant documentation]. Figure 4 and Figure 5 For multi-channel implementation examples, please refer to [link to example]. Figure 6 and Figure 7 .

[0034] Please refer to Figure 4 The diagram illustrates a schematic of a single-channel audio amplifier according to an embodiment of this application. The audio amplifier includes an audio amplifier chip, a filter, and a load; the audio amplifier chip is connected to a first terminal of the filter via an output port, the second terminal of the filter is grounded, the third terminal of the filter is connected to one end of the load, and the other end of the load is grounded.

[0035] The first filter includes an inductor. and capacitor .

[0036] It should be noted that the filter can have other structures. The above is the simplest case, including only one inductor and one capacitor. For example, it can also include multiple capacitors and inductors, or other components such as resistors; this is not limited here. When the filter includes only one inductor and one capacitor, the first terminal of the filter is... One end of the filter, the second end of the filter is At the other end, the third end of the filter is The other end and One end.

[0037] For example, the audio amplifier chip connects to the single-channel output port OUT A. One end is connected, The other end is respectively with Connected to one end of the first load. The other end of the load is grounded, and the other end of the first load is grounded.

[0038] Please refer to Figure 5The diagram illustrates a schematic of another two-channel audio amplifier provided in an embodiment of this application. The audio amplifier includes an audio amplifier chip, a filter, and a load; the audio amplifier chip is connected to a first end of the filter via an output port, the second end of the filter is grounded, the third end of the filter is connected to one end of the load, and the other end of the load is grounded.

[0039] The audio amplifier chip includes a half-bridge circuit, which corresponds to one of the output ports. The half-bridge circuit consists of two switching transistors connected in series. The input terminal of one of the switching transistors is connected to a positive power supply, the output terminal of one of the switching transistors is connected to the input terminal of the other switching transistor, and the output terminal of the other switching transistor is connected to a negative power supply.

[0040] The output terminal of one of the switching transistors and the input terminal of the other switching transistor are output ports.

[0041] For example, an audio amplifier chip includes a switching transistor. and A half-bridge circuit composed of series connections, and The midpoint of the series-connected half-bridge circuit is the single-channel output port OUT A. one end and and The midpoint (i.e., output port OUT A) of the series-connected half-bridge circuit is connected. The other end is respectively with Connect to one end of the first load; The other end of the load is grounded, and the other end of the first load is also grounded. The input terminal is connected to the positive power supply VDD. The output terminal is connected to the negative power supply VEE.

[0042] Please refer to Figure 6 The diagram illustrates a schematic of a two-channel audio amplifier provided in an embodiment of this application. The audio amplifier includes an audio amplifier chip, at least two filters, and at least two loads. The audio amplifier chip is connected to the first end of each of the filters via two output ports. The second ends of the two filters are connected together and then grounded. The third end of each filter is connected to one end of one of the loads. The other ends of the two loads are connected together and then grounded.

[0043] The first filter includes an inductor. and capacitor The second filter includes an inductor. and capacitor .

[0044] It should be noted that the filter can have other structures. The above is the simplest case, including only one inductor and one capacitor. For example, it can also include multiple capacitors and inductors, or other components such as resistors; this is not limited here. When the filter includes only one inductor and one capacitor, the first terminal of the filter is... One end of the filter, the second end of the filter is At the other end, the third end of the filter is The other end and One end.

[0045] For example, the audio amplifier chip connects to the output port OUT A of one of its channels. One end is connected, The other end is respectively with Connect to one end of the first load; The audio amplifier chip connects to the output port OUT B of another channel. One end is connected, The other end is respectively with One end of the load is connected to one end of the second load; The other end and The other end of the first load is connected to the ground, and the other end of the first load is connected to the other end of the second load and then grounded.

[0046] The audio amplifier provided in this application embodiment can drive a load with each channel and filter. Figure 1 Although the SE-connected load audio amplifier in the middle can drive a load with each channel and a filter, the filter structures of the two are different. Figure 1 The filter of the SE-connected load audio amplifier in the previous embodiment includes two capacitors and one resistor, while the filter of the audio amplifier provided in this application embodiment only includes one capacitor and one resistor. Therefore, compared to Figure 1 In the SE-connected load audio amplifier, the embodiments of this application can save one DC blocking capacitor for each channel. Figure 2 In BTL audio amplifiers, each pair of channels and two filters is required to drive one load. Therefore, compared to... Figure 2 The BTL audio amplifier in this application embodiment requires fewer channels and filters to drive a load. Figure 3 The PBTL audio amplifier in the middle requires four channels and two filters to drive one load, therefore, compared to Figure 3The PBTL audio amplifier in this application requires fewer channels and filters to drive a load. In summary, compared to existing solutions, this application's embodiments require fewer components to drive a load, resulting in lower application-level costs.

[0047] Please refer to Figure 7 The diagram illustrates a schematic of another two-channel audio amplifier provided in an embodiment of this application. The audio amplifier includes an audio amplifier chip, at least two filters, and at least two loads. The audio amplifier chip is connected to the first end of one of the filters via two output ports. The second ends of the two filters are connected and then grounded. The third end of each filter is connected to one end of one of the loads. The other ends of the two loads are connected and then grounded.

[0048] The audio amplifier chip includes at least two half-bridge circuits, each half-bridge circuit corresponding to one output port. The half-bridge circuit is composed of two switching transistors connected in series. The input terminal of one of the switching transistors is connected to a positive power supply, the output terminal of one of the switching transistors is connected to the input terminal of the other switching transistor, and the output terminal of the other switching transistor is connected to a negative power supply.

[0049] Among them, the output terminal of one of the switching transistors and the input terminal of the other switching transistor are output ports.

[0050] For example, an audio amplifier chip includes a switching transistor. and A half-bridge circuit composed of series connections, and The midpoint of the series-connected half-bridge circuit is the output port OUT A of one of the channels. one end and and The midpoint (i.e., output port OUT A) of the series-connected half-bridge circuit is connected. The other end is respectively with Connect to one end of the first load; The audio amplifier chip also includes a switching transistor. and A half-bridge circuit composed of series connections, and The midpoint of the series-connected half-bridge circuit is the output port OUT B of the other channel. One end connected to and The midpoints (i.e., output port OUT B) of the series-connected half-bridge circuit are connected. The other end is respectively with One end of the load is connected to one end of the second load; The other end and The other end of the first load is connected to the ground, and the other end of the first load is connected to the other end of the second load and then grounded.

[0051] and The input terminal is connected to the positive power supply VDD. and The output terminal is connected to the negative power supply VEE.

[0052] It can be seen that, Figure 1 and Figure 2 Existing audio amplifiers all use positive power supply. Figure 1 In the SE-connected load audio amplifier, the peak-to-peak voltage across the load is the power supply voltage. Figure 2 The BTL audio amplifier in this application, whether in BD mode or 1SPW mode, has a peak-to-peak voltage on the load that is twice the supply voltage. The audio amplifier provided in this embodiment uses asymmetrical power supply, compared to... Figure 1 The SE-connected load audio amplifier in this model achieves twice the peak load voltage with fewer components; compared to... Figure 2 The BTL audio amplifier in the model achieves the same peak load voltage with half the number of components.

[0053] Furthermore, the output voltage of the negative power supply VEE can be obtained by converting the output voltage of the positive power supply VDD through a DC-DC converter circuit.

[0054] In this embodiment, the output voltage of the negative power supply is obtained by converting the output voltage of the positive power supply, rather than being set separately. Structurally, this eliminates the need for additional power interfaces, transformers, or a second input, resulting in a more compact PCB layout, simplifying the system and saving space. Economically, it eliminates the need for a separate negative power supply module, connectors, and cables, significantly reducing the bill of materials cost. Simultaneously, the negative voltage automatically adjusts with the positive power supply, ensuring dual-power supply symmetry and improving the common-mode rejection performance of circuits such as operational amplifiers. Regarding the conversion method, a highly integrated DC-DC circuit is selected, requiring only a few external components to achieve a stable negative voltage output.

[0055] Furthermore, the audio amplifier chip includes at least two gate driving units, each gate driving unit corresponding to one half-bridge circuit. The gate driving unit is used to compare the amplified signal with a preset modulation signal and output a pulse width modulation signal. The pulse width modulation signal is used to alternately drive the gates of the two switching transistors so that current flows through the load. The amplified signal is obtained by conversion based on the input audio signal.

[0056] For example, the first gate driving unit and and The input terminals of the series-connected half-bridge circuit are connected, and the second gate drive unit is connected to... and The input terminals of the series-connected half-bridge circuit are connected. The input audio signal can be converted into an amplified signal through low-pass filtering, differential amplification, etc. Then, the gate drive unit compares the amplified signal with a preset modulation signal and outputs a pulse width modulation (PWM) signal. The gate drive unit can be, for example, a comparator, and the preset modulation signal can adopt various modulation schemes, such as a half-swing modulation scheme.

[0057] In one embodiment provided in this application, if the amplitude of the output signal of the audio amplifier chip is less than a preset amplitude threshold, the positive power supply is powered by a first fixed battery voltage, and the negative power supply is powered by a second fixed battery voltage, wherein the amplitude of the first fixed battery voltage is greater than the amplitude of the second fixed battery voltage. If the amplitude of the output signal of the audio amplifier chip is greater than or equal to the preset amplitude threshold and less than the amplitude of the battery voltage, then the positive power supply is powered by the first fixed battery voltage, and the negative power supply is powered by the first variable battery voltage that varies with the output signal of the audio amplifier chip. If the amplitude of the output signal of the audio amplifier chip is greater than or equal to the amplitude of the battery voltage, the positive power supply is powered by a second variable battery voltage that varies with the output signal of the audio amplifier chip; the negative power supply is powered by a third variable battery voltage that varies in the opposite direction with the output signal of the audio amplifier chip.

[0058] Please refer to Figure 8 This document illustrates a schematic diagram of the positive and negative power supply voltage variations of an audio amplifier according to an embodiment of this application. In this embodiment, the positive and negative power supplies employ asymmetrical power supply. When the audio amplifier has no output signal or requires a small output signal amplitude (e.g., less than 2V), the positive power supply uses a fixed voltage (e.g., 14V battery voltage), and the negative power supply uses a fixed small-amplitude negative voltage (e.g., -2V). Figure 8 In section A of the amplifier, when the required output signal amplitude is greater than 2V but less than the battery voltage (e.g., 14V), the positive power supply still uses a fixed battery voltage (e.g., 14V), while the negative power supply uses a negative voltage that varies with the output signal. Figure 8 In section B of the diagram; when the output signal required by the power amplifier is greater than the battery voltage, both the positive and negative power supplies use power supply voltages that vary with the output signal, such as... Figure 8 Section C in the middle.

[0059] In one embodiment provided in this application, the duty cycle of the pulse width modulation signal is determined based on the supply voltage of the positive power supply, the supply voltage of the negative battery, the voltage corresponding to the output signal of the audio amplifier chip, and a duty cycle determination formula. The duty cycle determination formula is as follows: , in, For PWM duty cycle, The supply voltage used by the positive power source includes the first fixed battery voltage and the second variable battery voltage. The supply voltage used by the negative power source includes the second fixed battery voltage, the first variable battery voltage, and the third variable battery voltage. This refers to the voltage corresponding to the output signal of the audio amplifier chip.

[0060] For most of the time, the audio power amplifier needs to output a relatively small signal amplitude. Correspondingly, for most of the time, the negative power supply of the amplifier needs a relatively small voltage amplitude. Taking an output amplitude of 0V as an example, when the audio power amplifier needs to output 0V, with a positive power supply voltage of, for example, 14V and a negative power supply voltage of, for example, -2V, to achieve an output voltage of 0, the duty cycle required by the H half-bridge is calculated using the duty cycle determination formula mentioned above: .

[0061] In existing technologies, to ensure that the positive and negative swings of the waveform are the same, the amplitudes of the positive and negative power supplies of the audio amplifier are set to the same value, such as + / -15V. This means that when there is no audio signal or the audio signal amplitude is small, the PWM duty cycle of the H half-bridge output needs to be close to 50%. However, in this application, the power amplifier output signal amplitude is small for most of the time, and the PWM output duty cycle is a relatively small value.

[0062] Please refer to Figure 9 This diagram illustrates the amplitude variation of the inductor current when the PWM duty cycle is 12.5% ​​and 50% according to an embodiment of this application. During the high PWM voltage period, the voltage at one end of the inductor in the filter is the positive power supply voltage, while the other end is close to 0V. The current in the inductor increases with a slope equal to the ratio of the positive power supply voltage to the inductance. As the PWM duty cycle decreases, the time maintained at the positive power supply voltage shortens, and the peak current in the inductor decreases proportionally. When the inductor current flows through the inductor and the switching transistor, a voltage drop and power loss occur due to the DC resistance of the inductor and the on-resistance of the switching transistor, the value of which is... , This is the total resistance value, including DC resistance and on-resistance.

[0063] In summary, compared with existing audio amplifiers, the audio amplifier provided in this application has a smaller PWM duty cycle in static state, which reduces the current flowing through the inductor and the switching transistor, thereby reducing static power loss.

[0064] Please refer to Figure 10 This illustration shows a flowchart of an audio amplifier drive control method according to an embodiment of this application. The method can be applied to computer devices, which refer to electronic devices with data computing and processing capabilities. The method may include the following steps: Step 1001: Convert the input audio signal to obtain the amplified signal; Step 1002: Compare the amplified signal with a preset modulation signal to obtain a pulse width modulation signal; Step 1003: Determine the duty cycle of the pulse width modulation signal by using the power supply voltage of the positive power supply, the power supply voltage of the negative battery, and the voltage corresponding to the output signal of the audio amplifier chip; Step 1004: Apply the pulse width modulation signal having the duty cycle to the gate of the switching transistor so that current flows through the load.

[0065] It should be noted that the input audio signal can be either a digital input audio signal or an analog input audio signal, and there is no limitation here.

[0066] Figure 11 A schematic diagram of an audio amplifier drive control device according to an embodiment of this application is shown. The device includes: The signal amplification unit 1101 is used to convert the input audio signal into an amplified signal. The PWM signal generation unit 1102 is used to compare the amplified signal with a preset modulation signal to obtain a pulse width modulation signal; Duty cycle determination unit 1103 is used to determine the duty cycle of the pulse width modulation signal by the power supply voltage used by the positive power supply, the power supply voltage used by the negative battery, and the voltage corresponding to the output signal of the audio amplifier chip. The drive control unit 1104 is configured to apply the pulse width modulation signal having the duty cycle to the gate of the switching transistor so that current flows through the load.

[0067] Figure 12 A schematic diagram of the structure of a computer device provided in one embodiment of this application is shown. The computer device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the functions of the computer system of the audio amplifier drive control method in any of the above embodiments.

[0068] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a computer, causes the computer to perform the functions of the computer system of the audio amplifier drive control method in any of the above embodiments.

[0069] This application also provides a computer program product containing instructions that, when executed by a computer, cause the computer to perform the functions of the computer system of the audio amplifier drive control method in any of the above embodiments.

[0070] It is understood that the specific examples in this application are only intended to help those skilled in the art better understand the implementation methods of this application, and are not intended to limit the scope of the invention.

[0071] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not limit the implementation process of the embodiments of this application in any way.

[0072] It is understood that the various implementation methods described in this application can be implemented individually or in combination, and the implementation methods in this application are not limited in this respect.

[0073] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0074] It is understood that the processor in the embodiments of this application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by the integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0075] It is understood that the memory in the embodiments of this application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Specifically, non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may be random access memory (RAM). It should be noted that the memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0076] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0077] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the aforementioned method implementations, and will not be repeated here.

[0078] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0079] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0080] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0081] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0082] The above are merely specific embodiments of this application, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. An audio amplifier, characterized in that, The audio amplifier includes an audio amplifier chip, a filter, and a load; the audio amplifier chip is connected to a first terminal of the filter via an output port, the second terminal of the filter is grounded, the third terminal of the filter is connected to one end of the load, and the other end of the load is grounded; The audio amplifier chip includes a half-bridge circuit and a gate driving unit. Each half-bridge circuit corresponds to one output port. The half-bridge circuit consists of two switching transistors connected in series. The input terminal of one switching transistor is connected to a positive power supply, the output terminal of one switching transistor is connected to the input terminal of the other switching transistor, and the output terminal of the other switching transistor is connected to a negative power supply. Each gate driving unit corresponds to one half-bridge circuit. The gate driving unit is used to compare the amplified signal with a preset modulation signal and output a pulse width modulation signal. The pulse width modulation signal is used to alternately drive the gates of the two switching transistors so that current flows through the load. The amplified signal is obtained by converting the input audio signal. If the amplitude of the output signal of the audio amplifier chip is less than a preset amplitude threshold, the positive power supply is powered by a first fixed battery voltage, and the negative power supply is powered by a second fixed battery voltage, wherein the amplitude of the first fixed battery voltage is greater than the amplitude of the second fixed battery voltage. If the amplitude of the output signal of the audio amplifier chip is greater than or equal to the preset amplitude threshold and less than the amplitude of the battery voltage, then the positive power supply is powered by the first fixed battery voltage, and the negative power supply is powered by the first variable battery voltage that varies with the output signal of the audio amplifier chip. If the amplitude of the output signal of the audio amplifier chip is greater than or equal to the amplitude of the battery voltage, the positive power supply is powered by a second variable battery voltage that varies with the output signal of the audio amplifier chip; the negative power supply is powered by a third variable battery voltage that varies in the opposite direction with the output signal of the audio amplifier chip.

2. The audio amplifier according to claim 1, characterized in that, The output voltage of the negative power supply is obtained by converting the output voltage of the positive power supply through a DC-to-DC circuit.

3. The audio amplifier according to claim 2, characterized in that, The duty cycle of the pulse width modulation signal is determined based on the supply voltage of the positive power supply, the supply voltage of the negative battery, the voltage corresponding to the output signal of the audio amplifier chip, and a duty cycle determination formula. The duty cycle determination formula is as follows: ， in, For PWM duty cycle, The supply voltage used by the positive power source includes the first fixed battery voltage and the second variable battery voltage. The supply voltage used by the negative power source includes the second fixed battery voltage, the first variable battery voltage, and the third variable battery voltage. This refers to the voltage corresponding to the output signal of the audio amplifier chip.

4. An audio amplifier driving control method, characterized in that, Applied to the audio amplifier of claim 3, the method includes: The amplified signal is obtained by converting the input audio signal; The amplified signal is compared with a preset modulation signal to obtain a pulse width modulation signal; The duty cycle of the pulse width modulation signal is determined by the supply voltage of the positive power supply, the supply voltage of the negative battery, and the voltage corresponding to the output signal of the audio amplifier chip. The pulse width modulation signal having the duty cycle is applied to the gate of the switching transistor so that current flows through the load.

5. An audio amplifier drive control device, characterized in that, Applied to the audio amplifier of claim 3, the device comprises: The signal amplification unit is used to convert the input audio signal into an amplified signal. A pulse width modulation signal generation unit is used to compare the amplified signal with a preset modulation signal to obtain a pulse width modulation signal; The duty cycle determination unit is used to determine the duty cycle of the pulse width modulation signal by taking the supply voltage of the positive power supply, the supply voltage of the negative battery, and the voltage corresponding to the output signal of the audio amplifier chip. A drive control unit is configured to apply the pulse width modulation signal having the duty cycle to the gate of the switching transistor so that current flows through the load.

6. An electronic device, characterized in that, include: Processor and memory; The processor is connected to a memory, wherein the memory is used to store a computer program, and the processor is used to invoke the computer program to execute the method as described in claim 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, perform the method as described in claim 4.

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