Audio amplification system with double D-class power amplifiers and low power supply stress based on phase reversal

Abstract

The invention discloses an audio amplification system based on phase reversal double-class-D power amplifier low power stress. The audio amplification system comprises a signal receiving and decoding module, an operational amplifier module, a double-group class-D power amplifier module, a filtering output module and a power supply module for supplying power to each module, which are connected with one another, a first operational amplifier unit in the operational amplifier module is configured to perform in-phase amplification on the analog audio signal; the second operational amplifier unit is configured to perform inverting amplification on the input signal; a first D-type power amplifier unit in a double-group D-type power amplifier module receives an in-phase signal and outputs an in-phase PWM (Pulse Width Modulation) power signal, and a second D-type power amplifier unit receives an inverted signal and outputs an inverted PWM power signal; and the first D-type power amplifier unit and the second D-type power amplifier unit work based on driving signals with opposite phases, so that peak current drawn from the power supply module is staggered or complementary in time to reduce instantaneous current stress and voltage fluctuation of the power supply module. The same audio output power is realized through ingenious signal phase management on the premise that the power supply cost is not increased or even reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of audio power amplification, and particularly relates to an audio amplification system with low power supply stress based on phase reversal of double D-class power amplifier. BACKGROUND

[0002] With the popularization of 4K / 8K ultra-high-definition video and audio and panorama sound technology, the market demand for the output power of home audio-visual equipment such as SoundBar is increasing, and the output power is increased from the traditional 500W level to the 1000W level to restore large dynamic audio. In order to meet the power output demand of 1000W level, the existing technology usually adopts two groups of 500W RMS D-class power amplifier units to realize the total output power by the same direction power superposition. However, this scheme has a significant defect: when outputting in the same direction, the two groups of power amplifiers will draw peak power from the same polarity end of the power supply at the same time, resulting in the peak power demand of the positive / negative pole of the power supply reaching 2000W (the peak power of a single D-class power amplifier is 1000W). At this time, if a power supply with a rated peak power lower than 2000W is selected, the protection mechanism is easily triggered under large dynamic signal, causing the power amplifier to stop, which affects the user experience; if a power supply with a rated peak power greater than or equal to 2000W is selected to avoid triggering the protection mechanism, the hardware cost of the power supply will be greatly increased (about 2 times of the 1000W power supply), and the volume of the power supply will also increase (the proportion of the internal space of the SoundBar is more than 30%), the heat dissipation power consumption will also increase, and a large area of heat dissipation fins or even a heat dissipation fan needs to be designed, which is contrary to the design requirement of small size and low cost of the home audio-visual equipment. SUMMARY

[0003] The present application provides an audio amplification system with low power supply stress based on phase reversal of double D-class power amplifier to overcome the above technical problems.

[0004] In order to achieve the above purpose, the technical scheme of the present application is: The application discloses an audio amplification system with low power supply stress based on phase reverse double D class power amplifier, which comprises signal receiving and decoding module, operational amplifier amplification module, double D class power amplifier module, filter output module and power supply module connected in sequence; the signal receiving and decoding module is used for receiving and decoding external audio signals to output analog audio signals; the operational amplifier amplification module comprises first operational amplifier unit and second operational amplifier unit; the first operational amplifier unit is configured to amplify the analog audio signals in phase and output in-phase signals; the second operational amplifier unit is configured to amplify the output signals of the first operational amplifier unit in reverse phase and output reverse-phase signals; the double D class power amplifier module comprises first D class power amplifier unit and second D class power amplifier unit connected to the output ends of the first operational amplifier unit and the second operational amplifier unit respectively; the first D class power amplifier unit receives the in-phase signals and outputs in-phase PWM power signals, and the second D class power amplifier unit receives the reverse-phase signals and outputs reverse-phase PWM power signals; Wherein, the first D class power amplifier unit and the second D class power amplifier unit work based on phase reverse driving signals, so that the peak current drawn from the power supply module is staggered or complementary in time, thereby reducing the instantaneous current stress and voltage fluctuation of the power supply module; The filter output module comprises first low-pass filter and second low-pass filter; the first low-pass filter is connected to the output end of the first D class power amplifier unit and used for filtering the in-phase PWM power signals to restore in-phase analog audio power signals; the second low-pass filter is connected to the output end of the second D class power amplifier unit and used for filtering the reverse-phase PWM power signals to restore reverse-phase analog audio power signals; The in-phase analog audio power signals and the reverse-phase analog audio power signals are configured to drive two loads respectively, and the total power is the sum of the powers received by the two loads respectively.

[0005] Further, the signal receiving and decoding module comprises wireless receiving module and digital audio processing module connected in sequence; The wireless receiving module is used for receiving external audio signals and converting the external audio signals into I2S digital signals; The digital audio processing module is used for compressing, enhancing and digital-analog converting the I2S digital signals to output analog audio signals.

[0006] Further, the first operational amplifier unit is a differential proportional amplifier, and the voltage gain is represented as: A v1 = 1 + R f1 / R1; The second operational amplifier unit is a reverse-phase proportional amplifier circuit, and the voltage gain is represented as: A v2 = -Rf2 R2 R2 f2 R2= 1, so that the maximum voltage output signal of the first operational amplifier unit is equal to the maximum voltage output signal of the second operational amplifier unit, that is, |V out1 | = | V out2 |; In the formula, R f1 and R f2 are the feedback resistances of the first operational amplifier unit and the second operational amplifier unit, respectively; R1 and R2 are the input resistances of the first operational amplifier unit and the second operational amplifier unit, respectively.

[0007] Further, the first class-D power amplifier unit and the second class-D power amplifier unit each include a PWM modulation driving module and a power switch output module connected in sequence; The PWM modulation driving module is configured to receive an output signal from the operational amplifier amplification module, compare it with an internal carrier wave, and generate a high-frequency PWM switching signal; The power switch output module is configured to convert the PWM switching signal into a PWM power signal under the control of the PWM switching signal.

[0008] Further, the digital audio processing module includes an ADAU1701 DSP chip; And the specific steps of the digital audio processing module for compressing, enhancing, and digital-to-analog converting the I2S digital signal to output an analog audio signal include: Amplitude compression of high-frequency signals within a set range through a DRC algorithm; Amplitude enhancement of low-frequency signals within a set range through an EQ algorithm; Decoding of the signals processed by the DRC algorithm and the EQ algorithm into an initial analog audio signal through a digital-to-analog converter.

[0009] Further, the first operational amplifier unit and the second operational amplifier unit each use an OPA1688 operational amplifier.

[0010] Further, the PWM modulation driving module includes an IRS2092 chip. Further, the power switch output module includes an upper bridge arm N-channel MOS tube and a lower bridge arm N-channel MOS tube, and the two MOS tubes are connected to form a power half-bridge; the gate of the power half-bridge is connected to the output end of the PWM modulation driving module.

[0011] Beneficial effects: The application sets the operational amplifier amplification module and the double-group class-D power amplifier module, configures the first operational amplifier unit in the operational amplifier amplification module to perform in-phase amplification on the analog audio signal; configures the second operational amplifier unit to perform inverse-phase amplification on the input signal; receives the in-phase signal by the first class-D power amplifier unit in the double-group class-D power amplifier module and outputs the in-phase PWM power signal, receives the inverse-phase signal by the second class-D power amplifier unit and outputs the inverse-phase PWM power signal; and the first class-D power amplifier unit and the second class-D power amplifier unit work based on the phase-opposite driving signals, so that the peak current drawn from the power supply module is staggered or complementary in time, to reduce the instantaneous current stress and voltage fluctuation of the power supply module. The same audio output power is achieved without increasing or even reducing the power supply cost through the ingenious signal phase management. The application can achieve the balance among high power, small size and low cost without sacrificing the output power, which meets the core demands of the consumer electronics market. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, below the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0013] Figure 1 The module structure diagram of the audio amplification system based on the phase-reversing double class-D power amplifier low power supply stress in the present application; Figure 2 The specific component structure diagram of the audio amplification system in the embodiment of the present application. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, below the technical solutions in the embodiments of the present application will be clearly and completely described with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0015] The embodiment provides an audio amplification system based on a phase-reversing double class-D power amplifier low power supply stress, as shown in Figure 1 and Figure 2 , comprising a signal receiving and decoding module, an operational amplifier amplification module, a double-group class-D power amplifier module, a filter output module and a power supply module for powering each module, which are connected in series. The signal receiving and decoding module is configured to receive and decode an external audio signal to output an analog audio signal. The operational amplifier amplification module comprises a first operational amplifier unit and a second operational amplifier unit; the first operational amplifier unit is configured to in-phase amplify the analog audio signal and output an in-phase signal, i.e., the output signal phase is the same as the input signal phase (φ1=0°); the second operational amplifier unit is configured to anti-phase amplify the output signal of the first operational amplifier unit and output an anti-phase signal, i.e., the output signal phase is opposite to the input signal phase (φ2=180°). The double-class D power amplifier module comprises a first class D power amplifier unit and a second class D power amplifier unit connected to the output ends of the first operational amplifier unit and the second operational amplifier unit, respectively; the first class D power amplifier unit receives the in-phase signal and outputs an in-phase PWM power signal, and the second class D power amplifier unit receives the anti-phase signal and outputs an anti-phase PWM power signal. The first class D power amplifier unit and the second class D power amplifier unit work based on driving signals with opposite phases, so that the peak current drawn from the power supply module is staggered or complementary in time, thereby reducing the instantaneous current stress and voltage fluctuation of the power supply module and achieving low power supply stress. The filter output module comprises a first low-pass filter and a second low-pass filter; the first low-pass filter is connected to the output end of the first class D power amplifier unit and is configured to filter the in-phase PWM power signal to restore it to an in-phase analog audio power signal; the second low-pass filter is connected to the output end of the second class D power amplifier unit and is configured to filter the anti-phase PWM power signal to restore it to an anti-phase analog audio power signal. The in-phase analog audio power signal and the anti-phase analog audio power signal are configured to drive two loads respectively, and the total power is the sum of the power received by each of the two loads, thereby achieving high power output.

[0016] In specific embodiments, the signal receiving and decoding module comprises a wireless receiving module and a digital audio processing module connected in sequence. The wireless receiving module is configured to receive an external audio signal and convert it to an I2S digital signal. The digital audio processing module is configured to compress, enhance, and digital-to-analog convert the I2S digital signal to output an analog audio signal.

[0017] In specific embodiments, the first operational amplifier unit is a differential proportional amplifier, and its voltage gain is represented as: A v1 = 1 + R f1 / R1; The second operational amplifier unit is an anti-phase proportional amplifier circuit, and its voltage gain is represented as: A v2= -R f2 / R2; set R f2 / R2=1, so that the maximum voltage output signal of the first op-amp unit is equal to the maximum voltage output signal of the second op-amp unit, i.e. out1 | = | V out2 |; In the formula, R f1 and R f2 are the feedback resistances of the first op-amp unit and the second op-amp unit, respectively; R1 and R2 are the input resistances of the first op-amp unit and the second op-amp unit, respectively.

[0018] Specifically, while optimizing the power stress, the embodiment ensures that the total harmonic distortion (THD) of the final output audio is less than 0.1% and the sound quality is lossless through precise gain matching and the use of high-fidelity components.

[0019] In specific embodiments, the first class-D power amplifier unit and the second class-D power amplifier unit each include a PWM modulation driving module and a power switch output module connected in sequence. The PWM modulation driving module is configured to receive an output signal from the op-amp amplification module and compare it with an internal carrier wave to generate a high-frequency PWM switching signal. The power switch output module is configured to perform high-speed switching under the control of the PWM switching signal and under the supply of ±70V power supply, so as to convert the PWM switching signal into a high-voltage and large-current PWM power signal.

[0020] Specifically, the low-pass filter module is an LC filter composed of an inductor and a capacitor, which is configured to filter out the high-frequency carrier component in the PWM power signal, and finally restore the analog audio power signal amplified by power to both ends of the load.

[0021] The embodiment designs a "forward + reverse" double op-amp unit: the first op-amp unit adopts OPA1688 to form a differential proportional amplifier, and the output signal is consistent in phase with the input signal; the second op-amp unit also adopts OPA1688 to form an inverting proportional amplifier, and the output signal is opposite in phase to the input signal, and through precise matching resistors, the amplitude of the two output signals is ensured to be consistent (error 1%), so as to realize two driving signals with opposite phases and equal amplitudes. Specifically, the power optimization principle of the embodiment is illustrated by comparison as follows, including: Define the key parameters: The rated output power of a single group of power amplifiers: P rms_single = 500W (RMS) The peak output power of a single group of power amplifiers: P peak_single= 1000W (user-given) The phase difference between the two power amplifier outputs is φ (φ=0° when they are in the same direction, and φ=180° when they are in opposite directions). (1) Power supply pressure when outputting in the same direction When φ=0°, the output waveforms of the two power amplifiers are completely synchronized: Peak moment of the positive half-cycle (t=t1): Both power amplifiers draw peak power P from the positive terminal of the power supply. peak_single Therefore, the peak power requirement of the positive power supply is: P peak_sync (+) = 1000W + 1000W = 2000W; At the peak of the negative half-cycle (t=t2): Both power amplifiers draw peak power P from the negative terminal of the power supply. peak_single Therefore, the peak power requirement of the negative power supply is: P peak_sync (-) = 1000W + 1000W = 2000W; At this point, the power supply needs to withstand a peak power of 2000W, which is prone to triggering protection, and a high-specification power supply must be selected.

[0022] (2) Power supply optimization during reverse output When φ=180°, the output waveforms of the two power amplifiers are completely out of phase: At the peak of the positive half-cycle (t=t1): The first Class D power amplifier unit draws P from the positive power supply. peak_single1 =1000W, the second Class D power amplifier unit draws P from the negative power supply. peak_single2 =1000W (negative half-cycle output), therefore: P peak_anti (+) = P peak_single1 = 1000 W; P peak_anti (-) = P peak_single2 = 1000 W; At the peak of the negative half-cycle (t=t2): The first Class D power amplifier unit draws Pp from the negative power supply. eak_single1 =1000W, the second Class D amplifier unit draws P from the positive power supply. peak_single2 =1000W, the peak power requirement at both the positive and negative ends of the power supply is still 1000W.

[0023] By reversing the phase, the peak power demand at the positive and negative terminals of the power supply is reduced from 2000W to 1000W, that is: ΔP peak = P peak_sync -P peak_anti = 2000W - 1000W = 1000W.

[0024] It can be seen from the above analysis that, due to the phase difference of 180° of the driving signal, the output waveforms of the first class-D power amplifier unit and the second class-D power amplifier unit are completely opposite, and when the first class-D power amplifier unit outputs the peak power in the positive half cycle, the second class-D power amplifier unit is just at the negative half cycle to output the peak power. Therefore, at the peak moment in the positive half cycle, the first power amplifier draws 1000W peak power from the positive pole of the power supply, while the second power amplifier draws 1000W peak power from the negative pole of the power supply; at the peak moment in the negative half cycle, the polarity of power draw is reversed. This makes the peak power demand of the positive and negative poles of the power supply be 1000W at any moment, which is 50% lower than the demand of 2000W when outputting in the same direction. Therefore, the ±70V DC power supply purchased by the embodiment only needs to have a rated peak power of ≥1000W to work stably, without the need for an expensive 2000W level power supply, achieving the effects of reducing the power supply cost by 50%, reducing the volume by 45%, and reducing the fin area by half, thereby realizing the optimization of power supply stress. At the same time, the reduced peak power demand effectively avoids the protection shutdown triggered by power overload under dynamic large signals, improving the continuity of audio playback and system stability.

[0025] In specific embodiments, the digital audio processing module includes an ADAU1701 DSP chip. And the specific steps of the digital audio processing module for compressing, enhancing and digital-to-analog conversion processing the I2S digital signal to output an analog audio signal include: The high-frequency signal in the set range is compressed in amplitude by a DRC algorithm; The low-frequency signal in the set range is amplified in amplitude by an EQ algorithm; The signal processed by the DRC algorithm and the EQ algorithm is decoded into an initial analog audio signal by a digital-to-analog converter.

[0026] Specifically, the embodiment compresses the excessive signal amplitude to 0-2Vpp to avoid subsequent operational amplifier overload; and amplifies the amplitude of the low-frequency signal with a frequency of 20Hz-100Hz by 2dB or 3dB, thereby enhancing the intensity of the input signal and making the output sound effect closer to the real effect and reducing distortion.

[0027] In specific embodiments, the first operational amplifier unit and the second operational amplifier unit both use OPA1688 operational amplifiers.

[0028] In specific embodiments, the PWM modulation driving module includes an IRS2092 chip. In specific embodiments, the power switch output module includes an upper bridge arm N-channel MOS tube (IPP175N20NM6) and a lower bridge arm N-channel MOS tube, and the two MOS tubes are connected to form a power half-bridge; the gate of the power half-bridge is connected to the output end of the PWM modulation driving module.

[0029] This embodiment focuses on the high-power audio amplification scene in home audio equipment, especially for power amplification of Sound Bar. Specifically, taking the "mid-to-high-end Sound Bar playing movie audio" scene as an example, there are six key stages from the transmission of electrical signals from the source to the processing process of the sound bar, including the signal form, processing process and parameter changes of each stage as follows: Stage 1: Signal source output (Sound Bar host) Initial signal: Movie audio signal is output in the form of wired HDMI or eARC signal (transmission rate 48 Gbps); Processing process: The Sound Bar host performs preliminary encoding (such as Dolby encoding) on the audio signal to ensure that there is no loss of sound quality during wireless transmission.

[0030] Stage 2: Signal reception and digital conversion (SWA52 module) Input signal: Sound Bar's audio bass signal; Processing process: (1) The SWA52 module uses a standard I2S interface output, with a sampling rate of 44.1 kHz~192 kHz, receiving the wireless audio signal of the Sound Bar; (2) The built-in ADC (Analog-to-Digital Converter) converts the analog radio frequency signal to a 24-bit depth, 44.1 kHz sampling rate I2S digital signal (including DATA data, CLK clock, LRCLK channel clock); Output signal: I2S digital signal, signal amplitude range is 0~3.3V (digital logic level).

[0031] Stage 3: Digital decoding and sound quality optimization (ADAU1701) Input signal: I2S digital signal output by SWA52; Processing process: (1) SigmaDSP core runs DRC algorithm: compresses excessive signal amplitude to 0~2Vpp to prevent subsequent circuit overload and enhances small signals; (2) Decodes the input digital signal to an analog audio signal of 0~2Vpp through the built-in DAC (Digital-to-Analog Converter); (3) Enhances the amplitude of low-frequency signals from 20Hz to 100Hz by 2dB through low-frequency enhancement method to enhance the impact of movie explosion sound and drum points.

[0032] Stage 4: Signal branching and phase optimization (operational amplifier amplification module) Input signal: 0~2Vpp analog audio signal output by ADAU1701; Processing procedure: (1) Signal splitting: One path is connected to the non-inverting input (Pin3) of OPA1688, and the other path is connected to the inverting input (Pin6). (2) Forward amplification (first op-amp unit): through 1 , f1 The differential proportional amplifier network formed has a gain A. v1 =1+ R f1 / R1=11 times, maximum voltage output signal V out1 =20Vpp, phase , and the V of the input signal in The phases are the same; (3) Inverting amplification (second op-amp unit): through 2 , f2 The resulting inverting proportional network has a gain A. v2 =-R f2 / R2=-1 times, maximum voltage output signal V out2 =20Vpp, phase , with input signal V in Their phases are opposite; (4) Output signal: Two analog audio signals with a maximum of 20Vpp each (connected to two Class D power amplifier modules respectively), with a phase difference of 180° and an amplitude error. 1%.

[0033] Phase 5: High-power amplification (dual Class D power amplifier modules) Input signals: Two analog signals output from two operational amplifier units; Processing procedure: (1) The IRS2092 driver chip receives analog signals, converts them into PWM (pulse width modulation) signals, and adjusts the pulse duty cycle according to the amplitude of the input signal; (2) The drive output terminal of IRS2092 outputs a PWM drive signal, which is then passed through a push-pull circuit to increase the drive capability and thus control the gate of the MOS transistor; (3) MOSFET turn on / off: When the PWM signal is high, the MOSFET is turned on, and the ±70V power supply supplies power to the load (speaker); when the signal is low, the MOSFET is turned off, and the high-frequency components are filtered out by the low-pass filter, thereby realizing power amplification. (4) Two power amplifier groups working together: in-phase group ( ) In the positive half cycle output high power, the reverse group ( ) In the negative half cycle output high power, the total power superposition is 1000W RMS; Output signal: 1000W RMS, Impedance matching audio power signal (connect the speaker), peak power 2000W, THD <0.1% (100Hz).

[0034] Stage 6: audio output (speaker) Input signal: 1000W power signal output by the double-class power amplifier module; Process: the speaker converts the electrical signal into mechanical vibration, restores the large dynamic and low frequency details of the movie audio, and the power supply system works stably without overload risk.

[0035] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A low-power-stress audio amplification system based on phase-reversing dual Class D power amplifiers, characterized in that, It includes a connected signal receiving and decoding module, an operational amplifier module, a dual-group Class D power amplifier module, a filter output module, and a power supply module that supplies power to each module; The signal receiving and decoding module is used to receive and decode external audio signals to output analog audio signals; The operational amplifier amplification module includes a first operational amplifier unit and a second operational amplifier unit; the first operational amplifier unit is configured to amplify the analog audio signal in phase and output an in-phase signal; the second operational amplifier unit is configured to amplify the output signal of the first operational amplifier unit in phase and output an in-phase signal. The dual-group Class D power amplifier module includes a first Class D power amplifier unit and a second Class D power amplifier unit, which are respectively connected to the output terminals of the first operational amplifier unit and the second operational amplifier unit; the first Class D power amplifier unit receives an in-phase signal and outputs an in-phase PWM power signal, and the second Class D power amplifier unit receives an in-phase signal and outputs an in-phase PWM power signal. The first Class D power amplifier unit and the second Class D power amplifier unit operate based on drive signals with opposite phases, so that the peak current drawn from the power module is staggered or complementary in time, thereby reducing the instantaneous current stress and voltage fluctuation of the power module. The filtering output module includes a first low-pass filter and a second low-pass filter; the first low-pass filter is connected to the output terminal of the first Class D power amplifier unit and is used to filter and restore the in-phase PWM power signal to an in-phase analog audio power signal; the second low-pass filter is connected to the output terminal of the second Class D power amplifier unit and is used to filter and restore the inverted PWM power signal to an inverted analog audio power signal. The in-phase analog audio power signal and the out-of-phase analog audio power signal are configured to drive two loads respectively, and the total power is the sum of the power received by each of the two loads.

2. The low-power-stress audio amplification system based on phase reversal dual Class D power amplifiers according to claim 1, characterized in that, The signal receiving and decoding module includes a wireless receiving module and a digital audio processing module connected in sequence. The wireless receiving module is used to receive external audio signals and convert them into I2S digital signals; The digital audio processing module is used to compress, enhance, and perform digital-to-analog conversion on the I2S digital signal to output an analog audio signal.

3. The low-power-stress audio amplification system based on phase reversal dual Class D power amplifiers according to claim 2, characterized in that, The first operational amplifier unit is a differential proportional amplifier, and its voltage gain is expressed as follows: A v1 = 1 + R f1 / R1; The second operational amplifier unit is an inverting proportional amplifier circuit, and its voltage gain is expressed as follows: A v2 = -R f2 / R2; Set R f2 / R2= 1, so that the maximum voltage output signal of the first op-amp unit is equal to the maximum voltage output signal of the second op-amp unit, i.e., |V out1 | = | V out2 |; In the formula, R f1 and R f2 R1 and R2 are the feedback resistors for the first and second operational amplifier units, respectively; R1 and R2 are the input resistors for the first and second operational amplifier units, respectively.

4. The low power supply stress audio amplification system based on phase reversal dual Class D power amplifiers according to claim 3, characterized in that, Both the first Class D power amplifier unit and the second Class D power amplifier unit include a PWM modulation drive module and a power switch output module connected in sequence; The PWM modulation driving module is used to receive the output signal from the operational amplifier module and compare it with the internal carrier to generate a high-frequency PWM switching signal. The power switch output module is used to convert the PWM switching signal into a PWM power signal under the control of the PWM switching signal.

5. The low power supply stress audio amplification system based on phase reversal dual Class D power amplifiers according to claim 4, characterized in that, The digital audio processing module includes an ADAU1701 DSP chip; The specific steps of the digital audio processing module in compressing, enhancing, and converting the I2S digital signal to an analog signal to output an analog audio signal include: Amplitude compression of high-frequency signals within a set range is performed using the DRC algorithm; The amplitude of low-frequency signals within a set range is increased using an EQ algorithm. The signal processed by the DRC algorithm and EQ algorithm is decoded into an initial analog audio signal by a digital-to-analog converter.

6. The low power supply stress audio amplification system based on phase reversal dual Class D power amplifiers according to claim 1, characterized in that, Both the first and second operational amplifier units use the OPA1688 operational amplifier.

7. The low-power-stress audio amplification system based on phase reversal dual Class D power amplifiers according to claim 4, characterized in that, The PWM modulation drive module includes an IRS2092 chip.

8. The low power supply stress audio amplification system based on phase reversal dual Class D power amplifier according to claim 4, characterized in that, The power switch output module includes an upper bridge arm N-channel MOSFET and a lower bridge arm N-channel MOSFET, and the two MOSFETs are connected to form a power half-bridge; the gate of the power half-bridge is connected to the output terminal of the PWM modulation drive module.

Images