High-quality echo cancellation circuit system

Abstract

The utility model discloses a high-quality echo cancellation circuit system, which comprises an audio component, a power supply anti-interference circuit, a front-end echo cancellation circuit and a power supply anti-interference circuit, the front-end echo elimination circuit comprises an echo reference signal circuit, an effective audio input signal circuit and a differential reduction circuit, the output end of the echo reference signal circuit and the output end of the effective audio input signal circuit are connected to the differential reduction circuit, and the output end of the differential reduction circuit is connected to the input end of the audio signal input circuit; the output end of the audio signal input circuit is connected to the audio processor, the audio processor is connected with the input end of the audio power amplifier, and the loudspeaker is driven by the audio power amplifier to realize audio amplification and playing functions.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the domestic embedded platform design field, concretely relates to a high quality echo cancellation circuit system. BACKGROUND

[0002] In modern communication technology, audio communication is a very important function, and audio communication technology plays an important role, which enables us to enjoy clear and understandable high-quality functional experience in voice call, audio and video playback and voice recognition. However, with the change of product materials, use environment and appearance size, the traditional audio processing technology is not up to the task when facing echo problem, and can not meet the user's demand for large volume and high quality of audio. Therefore, the development of high quality echo cancellation key technology becomes crucial. Based on the above actual situation, a high quality echo cancellation circuit system scheme is designed, which can effectively solve the problem of poor traditional audio echo cancellation ability, improve the quality of audio function, better improve the user experience, and promote the innovation of related audio technology and the development of industry. UTILITY MODEL CONTENT

[0003] The utility model is purposed at solving the problem of insufficient traditional audio echo cancellation ability, improving the user's audio use experience, and providing a high quality echo cancellation circuit system.

[0004] The utility model is implemented by the following technical scheme:

[0005] A high quality echo cancellation circuit system, comprising an audio assembly, a power anti-interference circuit and a front-end echo cancellation circuit;

[0006] The audio assembly comprises an audio processor, an audio signal input circuit and an audio power amplifier; the output end of the audio signal input circuit is connected to the audio processor, and the input end of the audio power amplifier is connected to the audio processor;

[0007] The power anti-interference circuit comprises a small ripple power supply, and the VDD3V3 output end of the small ripple power supply is respectively connected to the ACC3V3 output end, the DVCC3V3 output end and the VCC_MIC_PA output end through common mode inductance; wherein, the ACC3V3 output end is used for providing power for the operational amplifier; the DCC3V3 output end is used for providing power for the audio processor; and the VCC_MIC_PA output end is used for providing power for the audio power amplifier;

[0008] The front-end echo cancellation circuit comprises an echo reference signal circuit, an effective audio input signal circuit and a differential reduction circuit, the output end of the echo reference signal circuit and the output end of the effective audio input signal circuit are connected to the differential reduction circuit, and the output end of the differential reduction circuit is connected to the input end of the audio signal input circuit of the audio assembly.

[0009] In the above technical solution, the audio processor adopts a domestic audio processor AP8248A2, and the audio power amplifier adopts a high-quality audio power amplifier CS8122.

[0010] In the above technical solution, the small ripple power supply adopts an SGM6140XN6G / TR.

[0011] In the above technical solution, the audio power amplifier is externally connected with a loudspeaker to realize the audio external playing function.

[0012] In the above technical solution, the audio signal input circuit comprises a first operational amplifier, the first operational amplifier and a resistor-capacitor constitute a second-order filter, an audio signal input end is connected to a positive input end of the first operational amplifier through a resistor-capacitor device, and an audio signal output end of the first operational amplifier is connected to an audio signal output end of the audio signal input circuit through a resistor-capacitor device, the audio signal output end is connected to a signal input end of the audio processor, two differential audio signal output ends of the audio processor are connected to the audio power amplifier, the loudspeaker is driven by the audio power amplifier, and the audio amplification and playing functions are realized.

[0013] In the above technical solution, the echo reference signal circuit comprises a second operational amplifier, an echo reference signal input end is connected to a positive input end of the second operational amplifier through a resistor-capacitor device, and an echo reference signal output end of the second operational amplifier is connected to a signal output end of the second operational amplifier through a resistor-capacitor device.

[0014] The effective audio input signal circuit comprises a third operational amplifier, an effective audio input signal input end is connected to a negative input end of the third operational amplifier through a resistor-capacitor device, and an effective audio input signal output end of the third operational amplifier is connected to a signal output end of the third operational amplifier through a resistor-capacitor device.

[0015] The differential reduction circuit comprises a fourth operational amplifier, the echo reference signal output end of the echo reference signal circuit is connected to a positive input end of the fourth operational amplifier, the effective audio input signal output end of the effective audio input signal circuit is connected to a negative input end of the fourth operational amplifier, and a signal output end of the fourth operational amplifier is connected to an audio signal input end of the first operational amplifier.

[0016] In the above technical solution, any two of the first operational amplifier, the second operational amplifier, the third operational amplifier and the fourth operational amplifier share one operational amplifier chip SGM8295-2XS8G / TR.

[0017] The advantages and beneficial effects of the utility model are as follows:

[0018] 1,The utility model discloses a high -quality echo cancellation circuit system of professional level, which comprises a high -quality audio assembly, a high -quality audio processor chip, a low -noise operational amplifier and a high -quality audio power amplifier.

[0019] 2,The utility model discloses a good power anti -jamming circuit, including high -efficient small ripple power supply, filter circuit, grounding strategy, circuit layout, rely on high -efficient small ripple switching voltage stabilizing power supply and power filter circuit improves power quality, reduces the influence of power noise to audio signal.

[0020] 3,The utility model discloses a good front -end echo cancellation circuit, including echo reference signal circuit, effective audio input signal circuit, difference reduction circuit, aims at reducing echo amplitude through the mode of circuit.These circuits guarantee the quality and reliability of audio signal and greatly reduce echo amplitude by adopting separation extraction, reduction and other technical means.

[0021] The high-quality echo cancellation circuit system of the utility model can solve the problems of limited echo cancellation processing capacity, large delay and poor anti-interference in traditional audio technology, meet the high-standard requirements of modern audio applications and meet the trend of high-quality and high-performance development of current audio. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the overall structure schematic diagram of the high-quality echo cancellation circuit system of the utility model.

[0023] Figure 2.1 It is the circuit schematic diagram of the audio signal input circuit.

[0024] Figure 2.2 It is the circuit schematic diagram of the audio processor.

[0025] Figure 2.3 It is the circuit schematic diagram of the audio power amplifier.

[0026] Figure 3.1 It is the circuit schematic diagram of the small ripple power supply.

[0027] Figure 3.2 It is the circuit schematic diagram of the power anti-jamming circuit.

[0028] Figure 4.1 It is the circuit schematic diagram of the echo reference signal circuit.

[0029] Figure 4.2 It is the circuit schematic diagram of the effective audio input signal circuit.

[0030] Figure 4.3 It is the circuit schematic diagram of the difference reduction circuit. DETAILED DESCRIPTION

[0031] The technical scheme of the utility model is further illustrated below in combination with specific examples.

[0032] Referring to the accompanying drawings Figure 1 The utility model relates to a high -quality echo cancellation circuit system, including audio assembly, power anti -jamming circuit and front end echo cancellation circuit.

[0033] Among them, audio assembly is the hardware basis of realizing high -quality echo cancellation circuit system, needs to select high -performance audio assembly to guarantee that this technology can be realized. Good power anti -jamming circuit can effectively restrain external noise and electromagnetic interference, can keep the intelligibility and purity of audio signal, reduce noise and distortion, and power anti -jamning circuit is the necessary hardware design guarantee of high -quality echo cancellation circuit system. The front end echo cancellation circuit uses the method of reducing echo cancellation circuit, can effectively reduce echo amplitude, and speed up the echo cancellation processing speed. The whole system is on the basis of hardware circuit component selection, and circuit and algorithm jointly act, eliminate echo and improve audio signal quality significantly, thereby provide clear, professional audio experience.

[0034] Referring to the accompanying drawings Figure 2.1 - the accompanying drawings Figure 2.3 The audio assembly comprises an audio processor, an audio signal input circuit and an audio power amplifier, wherein the audio signal input circuit adopts a low-noise operational amplifier SGM8295-2XS8G / TR, which can effectively realize stable output of a small signal; the audio processor adopts a domestic audio processor AP8248A2, which can effectively reduce environmental noise and echo and ensure voice quality; and the audio power amplifier adopts a high-quality audio power amplifier CS8122, which can be externally connected with a loudspeaker to realize audio external playing function.

[0035] Specifically, the audio signal input circuit comprises a first operational amplifier, the first operational amplifier adopts an operational amplifier chip SGM8295-2XS8G / TR (two operational amplifiers are integrated on a single operational amplifier chip SGM8295-2XS8G / TR, wherein pins 1 to 3 are an operational amplifier, pins 5 to 7 are an operational amplifier, and pin 4 and pin 8 are a grounding and power supply end), and the first operational amplifier and a resistor and a capacitor constitute a second-order filter, an input audio signal SPK is connected to the positive input end (pin 5 of SGM8295-2XS8G / TR) of the first operational amplifier through a resistor and a capacitor device, and then the signal output end (pin 7 of SGM8295-2XS8G / TR) of the first operational amplifier is output through a resistor and a capacitor device, noise is filtered, and an output signal SPKIN is output; and the audio signal input circuit further comprises a second operational amplifier, the second operational amplifier is connected to the output signal SPKIN through a resistor and a capacitor device, and the second operational amplifier is connected to the first operational amplifier through a resistor and a capacitor device. Figure 2.1 Figure 2.2 ​The signal SPKIN is connected to the 8th pin of the audio processor AP8248A2, and the audio signal is transmitted to the audio processor AP8248A2 for processing, and then the differential audio signals SPKP and SPKN are output, and the audio signal is converted from a single-ended signal to a differential signal with strong anti-interference capability. Figure 2.3 The differential audio signals SPKP and SPKN of the audio processor AP8248A2 are respectively connected to the 3rd pin and the 4th pin of the audio power amplifier CS8122 through a resistor-capacitor device, and the loudspeaker is driven by the audio power amplifier CS8122 to realize the functions of audio amplification and playing.

[0036] Referring to FIG. 6, the audio power amplifier CS8122 is connected to the 3rd pin and the 4th pin of the audio processor AP8248A2 through a resistor-capacitor device, and the loudspeaker is driven by the audio power amplifier CS8122 to realize the functions of audio amplification and playing. Figure 3.1 and FIG. 6, Figure 3.2 The power anti-interference circuit mainly adopts power isolation filtering measures, and the 3.3V power supply used by the audio circuit is externally referenced to digital ground, and then the common-mode inductance is used to suppress common-mode interference, which can effectively attenuate the noise interference caused by the power supply line, and there are two 10uF and one 0.1uF capacitors at the input and output positions of the common-mode inductance, so as to ensure that the normal power transmission is not affected, and the quality and stability of the audio signal are improved.

[0037] Specifically, the power anti-interference circuit includes a small ripple power supply SGM6140XN6G / TR, and the VDD3V3 output end of the small ripple power supply SGM6140XN6G / TR is respectively connected to the ACC3V3 output end, the DVCC3V3 output end and the VCC_MIC_PA output end through a common-mode inductance; wherein the ACC3V3 output end is used to provide power for the operational amplifier chip SGM8295-2XS8G / TR; the DCC3V3 output end is used to provide power for the audio processor AP8248A2; and the VCC_MIC_PA output end is used to provide power for the audio power amplifier CS8122. In addition, a magnetic bead is specially used between the analog ground and the digital ground to reduce the interference between the digital ground and the analog ground. The above circuit design can effectively reduce the interference introduced by the power supply circuit, realize power isolation between subsystems, and ensure the reliability and stability of the power supply.

[0038] Referring to FIG. 6, the audio power amplifier CS8122 is connected to the 3rd pin and the 4th pin of the audio processor AP8248A2 through a resistor-capacitor device, and the loudspeaker is driven by the audio power amplifier CS8122 to realize the functions of audio amplification and playing. Figure 4.1 -FIG. 6, Figure 4.3The front-end echo cancellation circuit comprises an echo reference signal circuit, an effective audio input signal circuit and a differential cancellation circuit, the output end of the echo reference signal circuit and the output end of the effective audio input signal circuit are connected to the input end of the differential cancellation circuit, and the output end of the differential cancellation circuit is connected to the audio signal input circuit. The echo reference signal is transmitted to the differential cancellation circuit module through the echo reference signal circuit, the audio input signal is transmitted to the differential cancellation circuit module through the effective audio input signal circuit, and the audio input signal can effectively reduce the echo amplitude after cancellation with the echo reference signal in the differential cancellation circuit module.

[0039] Specifically, referring to the accompanying drawings Figure 4.1 The echo reference signal circuit comprises a second operational amplifier, the second operational amplifier adopts an operational amplifier chip SGM8295-2XS8G / TR, the echo reference signal HSHENG_IN is first connected to the positive input end of the second operational amplifier (5 pin of SGM8295-2XS8G / TR) through a resistance-capacitance device, and then is output from the signal output end (7 pin of SGM8295-2XS8G / TR) of the second operational amplifier through a resistance-capacitance device, so as to filter out noise and output a stable echo reference signal HSHENG_OUT.

[0040] Referring to the accompanying drawings Figure 4.2 The effective audio input signal circuit comprises a third operational amplifier, the third operational amplifier adopts an operational amplifier chip SGM8295-2XS8G / TR, the effective audio input signal MIC_IN is first connected to the negative input end of the third operational amplifier (2 pin of SGM8295-2XS8G / TR) through a resistance-capacitance device, and then is output from the signal output end (1 pin of SGM8295-2XS8G / TR) of the third operational amplifier through a resistance-capacitance device, so as to filter out noise and output a stable effective audio input signal MIC_OUT.

[0041] Referring to the accompanying drawings Figure 4.3The differential reduction circuit comprises a fourth operational amplifier, the echo reference signal HSHENG_OUT outputted by the echo reference signal circuit is connected to the positive input end (pin 3 of SGM8295-2XS8G / TR) of the fourth operational amplifier through resistance-capacitance connection, the effective sound frequency input signal MIC_OUT outputted by the effective sound frequency input signal circuit is connected to the negative input end (pin 2 of SGM8295-2XS8G / TR) of the fourth operational amplifier through resistance-capacitance connection, so as to realize the subtraction operation of the effective sound frequency input signal MIC_OUT and the echo reference signal HSHENG_OUT, achieve the purpose of reducing or eliminating the echo signal, and output the audio signal AUDIO_OUT which is not affected by the echo, the audio signal AUDIO_OUT is the input audio signal SPK described above and is inputted to the audio signal input circuit.

[0042] Further, any two of the first operational amplifier, the second operational amplifier, the third operational amplifier and the fourth operational amplifier share one operational amplifier chip SGM8295-2XS8G / TR. In the embodiment, the first operational amplifier and the third operational amplifier adopt one operational amplifier chip SGM8295-2XS8G / TR, and the second operational amplifier and the fourth operational amplifier adopt another operational amplifier chip SGM8295-2XS8G / TR.

[0043] The above has made the exemplary description of the utility model, it should be explained that, without departing from the core of the utility model, any simple deformation, modification or other equivalent replacement which can not spend the creative labor of the person skilled in the art falls into the protection scope of the utility model.

Claims

1. High-quality echo cancellation circuit system, comprising an audio component, a power anti-interference circuit and a front-end echo cancellation circuit; The audio component comprises an audio processor, an audio signal input circuit and an audio power amplifier; the output end of the audio signal input circuit is connected to the audio processor, and the input end of the audio processor is connected to the audio power amplifier; The power anti-interference circuit comprises a small ripple power supply, and the VDD3V3 output end of the small ripple power supply is connected to the ACC3V3 output end, the DVCC3V3 output end and the VCC_MIC_PA output end through common-mode inductors respectively; The front-end echo cancellation circuit comprises an echo reference signal circuit, an effective audio input signal circuit and a differential cancellation circuit; the output end of the echo reference signal circuit and the output end of the effective audio input signal circuit are connected to the differential cancellation circuit, and the output end of the differential cancellation circuit is connected to the input end of the audio signal input circuit of the audio component.

2. High quality echo cancellation circuitry according to claim 1, characterized in that: The audio processor adopts a domestic audio processor AP8248A2, and the audio power amplifier adopts an audio power amplifier CS8122.

3. High quality echo cancellation circuitry according to claim 1, characterized in that: The small ripple power supply adopts SGM6140XN6G / TR.

4. High quality echo cancellation circuitry in accordance with claim 1, characterized in that: The audio power amplifier is externally connected to a loudspeaker.

5. The high-quality echo-cancellation circuitry of claim 1, wherein: The audio signal input circuit comprises a first operational amplifier, the audio signal input end is connected to the positive input end of the first operational amplifier through a resistance-capacitance device, and the signal output end of the first operational amplifier is connected to the audio signal output end of the audio signal input circuit through a resistance-capacitance device, which is connected to the signal input end of the audio processor; the two differential audio signal output ends of the audio processor are connected to the audio power amplifier.

6. High quality echo cancellation circuitry according to claim 5, characterized in that: The echo reference signal circuit comprises a second operational amplifier, the echo reference signal input end is connected to the positive input end of the second operational amplifier through a resistance-capacitance device, and the signal output end of the second operational amplifier is connected to the echo reference signal output end through a resistance-capacitance device; The effective audio input signal circuit comprises a third operational amplifier, the effective audio input signal input end is connected to the negative input end of the third operational amplifier through a resistance-capacitance device, and the signal output end of the third operational amplifier is connected to the effective audio input signal output end through a resistance-capacitance device; The differential cancellation circuit comprises a fourth operational amplifier, the echo reference signal output end of the echo reference signal circuit is connected to the positive input end of the fourth operational amplifier, the effective audio input signal output end of the effective audio input signal circuit is connected to the negative input end of the fourth operational amplifier, and the signal output end of the fourth operational amplifier is connected to the audio signal input end of the first operational amplifier.

7. High quality echo cancellation circuitry according to claim 6, characterised in that: Any two of the first operational amplifier, the second operational amplifier, the third operational amplifier and the fourth operational amplifier share one operational amplifier chip SGM8295-2XS8G / TR.

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