Audio recollection amplitude adaptation circuit and method

Abstract

The present invention relates to the field of electronic technology and provides an audio recapture amplitude adaptation circuit and method, wherein the circuit is connected to an output terminal of a playback device, the output terminal of an audio recapture module in the circuit is respectively connected to a signal receiving module, a signal amplitude comparison module, and a recapture adjustment module. The signal receiving module is connected to the recapture adjustment module via the signal amplitude comparison module, and the recapture adjustment module is connected to a voltage divider filter unit. The resistance of a voltage divider resistor in the voltage divider filter unit is adjusted so that the voltage value of a first audio signal output after voltage divider filtering of an original audio signal output by the playback device does not exceed a reference voltage value. When the original audio signal or the reference voltage value changes, the circuit can promptly adjust the resistance of the voltage divider resistor in the voltage divider filter unit so that the voltage value of the audio signal output by the voltage divider filter unit does not exceed the reference voltage value, thereby avoiding damage to the audio chip or poor echo cancellation effect, and ensuring stable audio recapture effect.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to an audio recollection amplitude adaptation circuit and method. Background Art

[0002] The audio recapture circuit converts the original audio signal from the playback device into an audio signal of appropriate amplitude after voltage division and filtering. This signal is then passed to the audio chip, where internal algorithms are used to process the audio signal at the appropriate amplitude, ultimately achieving echo cancellation. In the audio recapture circuit, the voltage divider resistors are determined based on the amplitude range of the original audio signal output by the playback device and the amplitude range of the audio signal allowed by the audio chip. The original audio signal is adjusted based on the ratio of the voltage divider resistors, ultimately ensuring that the amplitude range of the audio signal after voltage division and filtering is within the audio signal amplitude range allowed by the audio chip.

[0003] The existing audio recapture circuit is only applicable to playback devices and audio chips with fixed specifications. When replacing playback devices or audio chips with other specifications, the amplitude range of the original audio signal output by the playback device and the amplitude range of the audio signal allowed to be input by the audio chip will change. Specifically, when the audio signal after voltage division and filtering exceeds the amplitude range allowed to be input by the audio chip, the input audio signal will be distorted and even the chip will be damaged; and if the audio signal after voltage division and filtering is too small, the echo cancellation effect will be poor. Due to the poor compatibility of the audio recapture circuit, as the demand for replacing playback devices and audio chips continues to increase, each replacement of the playback device or audio chip requires re-debugging and verification of the audio recapture circuit parameters, which greatly increases the time and hardware costs of developers. Summary of the Invention

[0004] In response to the shortcomings of the above-mentioned existing technologies, the present invention provides an audio recapture amplitude adaptation circuit and method, which solves the technical problem in the existing technology that when the playback device or audio chip connected to the audio recapture circuit is replaced, the audio recapture circuit parameters need to be re-debugged and verified.

[0005] On one hand, the present invention provides an audio recapture amplitude adaptation circuit, which is connected to the output end of a playback device. The audio recapture amplitude adaptation circuit includes an audio recapture module, a signal receiving module, a signal amplitude comparison module, and a recapture adjustment module. The audio recapture module includes a voltage divider filter unit, wherein:

[0006] The first input end of the audio recollection module is connected to the output end of the playback device, the first output end of the audio recollection module is connected to the input end of the signal receiving module, the second output end of the audio recollection module is connected to the first input end of the signal amplitude comparison module, and the third output end of the audio recollection module is connected to the first input end of the recollection adjustment module;

[0007] The output end of the signal receiving module is connected to the second input end of the signal amplitude comparison module, the output end of the signal amplitude comparison module is connected to the second input end of the re-sampling adjustment module, and the output end of the re-sampling adjustment module is connected to the voltage divider filtering unit, wherein the re-sampling adjustment module is used to adjust the resistance of the voltage divider resistor in the voltage divider filtering unit so that the voltage value of the first audio signal output by the original audio signal output by the playback device after voltage division and filtering by the voltage divider filtering unit does not exceed a preset reference voltage value.

[0008] Optionally, the voltage-dividing filter unit includes a first filter capacitor, a first voltage-dividing resistor, a second filter capacitor, a second voltage-dividing resistor and a third filter capacitor, wherein:

[0009] The input end of the voltage-dividing filter unit is connected to the output end of the playback device, the input end of the voltage-dividing filter unit is connected to the first end of the first filter capacitor, the second end of the first filter capacitor is connected to the first end of the first voltage-dividing resistor, the second end of the first voltage-dividing resistor is connected to the first end of the second filter capacitor, the second end of the second filter capacitor is connected to the ground end, and the second filter capacitor is connected in parallel with the second voltage-dividing resistor, the second end of the first voltage-dividing resistor is also connected to the first output end of the voltage-dividing filter unit, and the first output end of the voltage-dividing filter unit is respectively connected to the input end of the signal amplitude comparison module and the input end of the recovery adjustment module;

[0010] The second end of the first voltage-dividing resistor is connected to the first end of the third filter capacitor, the second end of the third filter capacitor is connected to the second output end of the voltage-dividing filter unit, and the second output end of the voltage-dividing filter unit is connected to the input end of the signal receiving module.

[0011] Optionally, the signal receiving module includes an audio chip and a bias power supply, the audio chip includes a signal input pin and a signal output pin, the signal input pin is connected to the output end of the bias power supply, wherein,

[0012] The signal input pin of the audio chip is connected to the output end of the audio recollection module, and the signal output pin of the audio chip is connected to the input end of the signal amplitude comparison module.

[0013] Optionally, the signal amplitude comparison module includes an operational amplifier unit and a signal comparison unit, wherein:

[0014] The first input end of the operational amplifier unit is connected to the output end of the audio recollection module, the second input end of the operational amplifier unit is connected to the output end of the signal receiving module, and the output end of the operational amplifier unit is connected to the first input end of the signal comparison unit;

[0015] The second input end of the signal comparison unit is connected to the output end of the audio recovery module, and the output end of the signal comparison unit is connected to the input end of the recovery adjustment module.

[0016] Optionally, the operational amplifier unit includes a subtraction circuit and an operational amplifier chip, and the operational amplifier chip includes an operational amplifier input pin and an operational amplifier output pin, wherein:

[0017] The first input end of the operational amplifier unit and the second input end of the operational amplifier unit are respectively connected to the operational amplifier input pin of the operational amplifier chip through the subtraction circuit, and the operational amplifier output pin of the operational amplifier chip is connected to the output end of the operational amplifier unit.

[0018] Optionally, the subtraction circuit includes a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, and a sixth voltage-dividing resistor, and the op amp input pin includes an op amp input positive pin and an op amp input negative pin, wherein,

[0019] The first input terminal of the operational amplifier unit is connected to the operational amplifier input positive pin through the third voltage-dividing resistor, and the operational amplifier input positive pin is connected to the ground terminal through the fourth voltage-dividing resistor;

[0020] The second input end of the operational amplifier unit is connected to the operational amplifier input negative pin through the fifth voltage-dividing resistor, the operational amplifier input negative pin is connected to the operational amplifier output pin through the sixth voltage-dividing resistor, and the operational amplifier output pin is connected to the output end of the operational amplifier unit.

[0021] Optionally, the signal comparison unit includes a control chip, and the control chip includes a first input pin, a second input pin, and an output pin, wherein:

[0022] The first input pin is connected to the output end of the audio recovery module, the second input pin is connected to the output end of the operational amplifier unit, and the output pin is connected to the input end of the recovery adjustment module.

[0023] Optionally, the recovery adjustment module includes a resistance adjustment unit, a first input end of the resistance adjustment unit is connected to the output end of the audio recovery module, a second input end of the resistance adjustment unit is connected to the output pin of the control chip, and the output end of the resistance adjustment unit is connected to the voltage divider filter unit of the audio recovery module.

[0024] Optionally, the resistance adjustment unit includes a multiple-choice analog switch chip, the multiple-choice analog switch chip includes at least two input pins, a signal receiving pin and a ground pin, wherein:

[0025] Each of the at least two input pins is connected to the output end of the audio recovery module through an adjustment resistor, and each of the adjustment resistors is connected in parallel with the second voltage divider resistor in the voltage divider filter unit, the signal receiving pin is connected to the output pin of the control chip, and the ground pin is connected to the ground end.

[0026] Optionally, the output pin of the control chip includes an enable control output pin and multiple chip select output pins, the signal receiving pin of the multiple-select-one analog switch chip includes an enable control input pin and multiple chip select input pins, and the number of the chip select output pins is equal to the number of the chip select input pins, wherein,

[0027] The enable control output pin is connected to the enable control input pin, and the multiple chip select output pins are respectively connected to the multiple chip select input pins in a one-to-one correspondence.

[0028] The present invention provides an audio recapture amplitude adaptation circuit. An audio recapture module receives an original audio signal transmitted by a playback device and processes the original audio signal through a voltage divider filter unit to obtain a first audio signal. The first audio signal is then transmitted to a signal receiving module to achieve echo cancellation. The signal receiving module outputs a second audio signal. A signal amplitude comparison module is connected to the audio recapture module and the signal receiving module, respectively, to receive the first and second audio signals, compare and calculate them, and determine a preset reference voltage value. The reference voltage value is then transmitted to a recapture adjustment module. The recapture adjustment module adjusts the resistance of a voltage divider resistor in the voltage divider filter unit of the audio recapture module to ensure that the voltage value of the first audio signal does not exceed the preset reference voltage value. When the connected playback device and signal receiving module are replaced, that is, when the original audio signal or the reference voltage value changes, the circuit can promptly adjust the resistance of the voltage divider resistor in the voltage divider filter unit of the audio recapture module to ensure that the voltage value of the audio signal at the voltage divider filter unit does not exceed the reference voltage value, thereby preventing damage to the audio chip or poor echo cancellation performance, and ensuring stable audio recapture.

[0029] Another aspect of the present invention provides an audio recapture amplitude adaptation method, which is applied to any of the above-mentioned audio recapture amplitude adaptation circuits, and includes:

[0030] The audio recollection module receives the original audio signal sent by the playback device, performs voltage division filtering on the original audio signal through the voltage division filtering unit, and outputs a first audio signal;

[0031] The signal receiving module receives the first audio signal and performs echo cancellation on the first audio signal to obtain a second audio signal;

[0032] The signal amplitude comparison module receives the first audio signal and the second audio signal, performs a subtraction calculation based on the first audio signal and the second audio signal to obtain a reference voltage value, compares the first audio signal based on the reference voltage value, and outputs a comparison result;

[0033] The sampling adjustment module receives the comparison result and adjusts the resistance value of the resistor in the voltage-dividing filter unit based on the comparison result so that the voltage value of the first audio signal does not exceed the reference voltage value.

[0034] The audio recapture amplitude adaptation method provided by the present invention enables, regardless of whether the playback device or the audio chip connected to the audio recapture amplitude adaptation circuit is replaced, that is, when the original audio signal or the reference voltage value changes, to obtain a reference voltage by performing a subtraction calculation on the first audio signal output by the audio recapture module and the second audio signal output by the signal receiving module, and to compare the first audio signal with the reference voltage. Based on the comparison result, the resistance value of the voltage divider resistor in the voltage divider filter unit in the audio recapture module is adjusted in time, so that the peak range of the voltage value of the audio signal output by the voltage divider filter unit does not exceed the reference voltage value, thereby avoiding damage to the audio chip or poor echo cancellation effect, and ensuring the stability of the audio recapture effect.

[0035] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0036] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0038] Figure 1 A schematic diagram of the structure of an audio recovery amplitude adaptation circuit in one embodiment provided in this application;

[0039] Figure 2 A schematic diagram of the structure of an audio recovery amplitude adaptation circuit in one embodiment provided in this application;

[0040] Figure 3 A circuit diagram of a voltage divider filter unit in one embodiment provided in this application;

[0041] Figure 4 A circuit diagram of an operational amplifier unit in one embodiment provided in this application;

[0042] Figure 5 A circuit diagram of a recovery adjustment module in one embodiment provided in this application;

[0043] Figure 6 A flowchart diagram of an audio capture amplitude adaptation method in an embodiment provided in this application. DETAILED DESCRIPTION

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0046] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0047] On one hand, the present invention provides an audio frequency recovery amplitude adaptation circuit, such as Figure 1 As shown, the audio recapture amplitude adaptation circuit is connected to the output end of the playback device, and the audio recapture amplitude adaptation circuit includes an audio recapture module, a signal receiving module, a signal amplitude comparison module and a recapture adjustment module. The audio recapture module includes a voltage divider filter unit, wherein the first input end of the audio recapture module is connected to the output end of the playback device, the first output end of the audio recapture module is connected to the input end of the signal receiving module, the second output end of the audio recapture module is connected to the first input end of the signal amplitude comparison module, and the third output end of the audio recapture module is connected to the first input end of the recapture adjustment module; the output end of the signal receiving module is connected to the second input end of the signal amplitude comparison module, the output end of the signal amplitude comparison module is connected to the second input end of the recapture adjustment module, and the output end of the recapture adjustment module is connected to the voltage divider filter unit, wherein the recapture adjustment module is used to adjust the resistance value of the voltage divider resistor in the voltage divider filter unit so that the voltage value of the first audio signal output by the playback device after voltage divider filtering by the voltage divider filter unit does not exceed a preset reference voltage value.

[0048] The present invention provides an audio recapture amplitude adaptation circuit. An audio recapture module receives an original audio signal transmitted by a playback device and processes the original audio signal through a voltage divider filter unit to obtain a first audio signal. The first audio signal is then transmitted to a signal receiving module to achieve echo cancellation. The signal receiving module outputs a second audio signal. A signal amplitude comparison module is connected to the audio recapture module and the signal receiving module, respectively, to receive the first and second audio signals, compare and calculate them, and determine a preset reference voltage value. The reference voltage value is then transmitted to a recapture adjustment module. The recapture adjustment module adjusts the resistance of a voltage divider resistor in the voltage divider filter unit of the audio recapture module to ensure that the voltage value of the first audio signal does not exceed the preset reference voltage value. When the connected playback device and signal receiving module are replaced, that is, when the original audio signal or the reference voltage value changes, the circuit can promptly adjust the resistance of the voltage divider resistor in the voltage divider filter unit of the audio recapture module to ensure that the voltage value of the audio signal at the voltage divider filter unit does not exceed the reference voltage value, thereby preventing damage to the audio chip or poor echo cancellation performance, and ensuring stable audio recapture.

[0049] Specifically, the traditional audio recapture circuit processes the original audio signal output by the playback device through a voltage divider filter to obtain an audio signal of appropriate amplitude, and then sends the audio signal of appropriate amplitude after voltage divider filtering to the audio chip used to receive the audio signal. The audio chip processes the audio signal through an internal algorithm and ultimately realizes the echo cancellation function. There are two key parameters in the entire audio recapture circuit. One parameter is the amplitude range of the original audio signal output by the playback device, and the other parameter is the amplitude range of the audio signal after voltage divider filtering allowed to be input by the audio chip used to receive the audio signal. This amplitude range is determined by the static bias voltage inside the input end of the audio chip. In actual application scenarios, there is often a need to replace the playback device and the audio chip, which causes the amplitude range of the original audio signal or the amplitude range of the audio signal after voltage division and filtering allowed by the audio chip to change. On the basis of the parameters of the audio recovery circuit remaining unchanged, when the audio signal after voltage division and filtering becomes larger and exceeds the amplitude range allowed by the audio chip, the input audio signal is distorted and even causes damage to the chip; when the audio signal after voltage division and filtering is reduced, the audio signal will be too small, affecting the processing of the internal algorithm of the audio chip and resulting in poor echo cancellation effect.

[0050] In this application, the original audio signal output by the playback device includes four audio signals, namely SPK_IN_L+left channel negative and positive poles, SPK_IN_L-left channel negative poles, SPK_IN_R+right channel positive poles and SPK_IN_R-right channel negative poles. The following specific discussion takes the SPK_IN_L+left channel negative and positive poles signal as an example, and the same applies to the other three signals.

[0051] Further, such as Figure 3 As shown, the voltage-dividing filter unit includes a first filter capacitor C1, a first voltage-dividing resistor R1, a second filter capacitor C2, a second voltage-dividing resistor R2 and a third filter capacitor C3, wherein the input end of the voltage-dividing filter unit is connected to the output end of the playback device, the input end of the voltage-dividing filter unit is connected to the first end of the first filter capacitor C1, the second end of the first filter capacitor C1 is connected to the first end of the first voltage-dividing resistor R1, the second end of the first voltage-dividing resistor R1 is connected to the first end of the second filter capacitor C2, the second end of the second filter capacitor C2 is connected to the ground end, and the second filter capacitor C2 is connected to the second voltage-dividing resistor R2 in parallel, the second end of the first voltage-dividing resistor R1 is also connected to the first output end of the voltage-dividing filter unit, and the first output end of the voltage-dividing filter unit is respectively connected to the input end of the signal amplitude comparison module and the input end of the sampling adjustment module; the second end of the first voltage-dividing resistor R1 is connected to the first end of the third filter capacitor C3, the second end of the third filter capacitor C3 is connected to the second output end of the voltage-dividing filter unit, and the second output end of the voltage-dividing filter unit is connected to the input end of the signal receiving module.

[0052] In this embodiment, the playback device outputs the original audio signal SPK_IN_L+, and the original audio signal SPK_IN_L+ is transmitted to the input end of the voltage divider filter unit. After passing through the first filter capacitor C1, the DC component in the original audio signal SPK_IN_L+ can be filtered out, and then the original audio signal SPK_IN_L+ is divided, compressed, subtracted and filtered in sequence through the first voltage divider resistor R1 and according to the resistance ratio of the resistors to obtain the first audio signal SPK_L+ after voltage divider filtering. The first output end of the voltage divider filter unit sends the first audio signal SPK_L+ to the signal amplitude comparison module and the sampling adjustment module respectively, and the first audio signal SPK_L+ is sent to the signal receiving module through the second output end of the voltage divider filter unit after passing through the third filter capacitor C3. On the one hand, the voltage divider filtering unit performs voltage divider filtering on the original audio signal SPK_IN_L+ and transmits the first audio signal SPK_L+ obtained after processing to the signal receiving module to realize its basic function. On the other hand, the first audio signal SPK_L+ is sent to the signal amplitude comparison module and the sampling adjustment module respectively, so that the first audio signal SPK_L+ after voltage divider filtering can be subsequently compared and calculated.

[0053] Furthermore, the signal receiving module includes an audio chip and a bias power supply. The audio chip includes a signal input pin and a signal output pin. The signal input pin is connected to the output end of the bias power supply. The signal input pin of the audio chip is connected to the output end of the audio acquisition module, and the signal output pin of the audio chip is connected to the input end of the signal amplitude comparison module.

[0054] In this embodiment, the audio chip in the signal receiving module receives the first audio signal SPK_L+ obtained after voltage division and filtering processing. The first audio signal SPK_L+ flows into the signal input pin of the audio chip and is processed by the internal algorithm mechanism of the audio chip to realize the echo cancellation function. This application does not limit the selection of the audio signal model. Since the signal input pin of the audio chip signal is connected to the output end of the bias power supply, the first audio signal SPK_L+ is processed by the audio chip and outputs the second audio signal AUD_L+ with a static bias voltage through the signal output pin, and the second audio signal AUD_L+ is sent to the signal amplitude comparison module for comparison and calculation with the first audio signal SPK_L+.

[0055] Specifically, in the above embodiment, Figure 2As shown, the signal amplitude comparison module includes an operational amplifier unit and a signal comparison unit, wherein the first input end of the operational amplifier unit is connected to the output end of the audio recovery module, the second input end of the operational amplifier unit is connected to the output end of the signal receiving module, and the output end of the operational amplifier unit is connected to the first input end of the signal comparison unit; the second input end of the signal comparison unit is connected to the output end of the audio recovery module, and the output end of the signal comparison unit is connected to the input end of the recovery adjustment module.

[0056] In this embodiment, "op amp" is short for operational amplifier, and the operation unit is an amplifying circuit for performing mathematical operations on signals. The op amp unit is connected to the audio recapture module and the signal receiving module, respectively, to receive a first audio signal SPK_L+ output by the audio recapture module and a second audio signal AUD_L+ with a static bias voltage output by the signal receiving module. The op amp unit calculates the first audio signal SPK_L+ and the second audio signal AUD_L+ to obtain a preset reference voltage value for the signal receiving module. This preset reference voltage value corresponds to the amplitude range of the voltage-divided filtered audio signal allowed by the audio chip in the signal receiving module. The output of the op amp unit is connected to a signal comparison unit, which is also connected to the audio recapture module. The signal comparison unit compares the reference voltage value with the first audio signal SPK_L+ to obtain a comparison result. The comparison result is transmitted to the recapture adjustment module in the form of a level signal, which serves as the basis for the recapture adjustment module to adopt an adjustment strategy for the voltage-dividing filter unit in the audio recapture module.

[0057] Furthermore, the operational amplifier unit includes a subtraction circuit and an operational amplifier chip, and the operational amplifier chip includes an operational amplifier input pin and an operational amplifier output pin, wherein the first input end of the operational amplifier unit and the second input end of the operational amplifier unit are respectively connected to the operational amplifier input pin of the operational amplifier chip through the subtraction circuit, and the operational amplifier output pin of the operational amplifier chip is connected to the output end of the operational amplifier unit.

[0058] In this embodiment, the operational amplifier unit is used to calculate the first audio signal SPK_L+ and the second audio signal AUD_L+ to obtain a preset reference voltage value of the signal receiving module. Specifically, the first audio signal SPK_L+ and the second audio signal AUD_L+ are connected to the operational amplifier input pin of the operational amplifier chip through a subtraction circuit for subtraction calculation. The voltage value of the first audio signal SPK_L+ is subtracted from the voltage value of the second audio signal AUD_L+, that is, the audio signal without a bias voltage is subtracted from the audio signal with a bias voltage. The obtained voltage value is the reference voltage, that is, the static bias voltage of the audio chip. The operational amplifier output pin of the operational amplifier chip transmits the static bias voltage to the signal comparison unit through the output end of the operational amplifier unit.

[0059] Further, such as Figure 4As shown, the subtraction circuit includes a third voltage-dividing resistor R3, a fourth voltage-dividing resistor R4, a fifth voltage-dividing resistor R5 and a sixth voltage-dividing resistor R6, and the op amp input pins include an op amp input positive pin INA+ and an op amp input negative pin INA-, wherein the first input end of the op amp unit is connected to the op amp input positive pin INA+ through the third voltage-dividing resistor R3, and the op amp input positive pin INA+ is connected to the ground end through the fourth voltage-dividing resistor R4; the second input end of the op amp unit is connected to the op amp input negative pin INA- through the fifth voltage-dividing resistor R5, and the op amp input negative pin INA- is connected to the op amp output pin OUTA through the sixth voltage-dividing resistor R6, and the op amp output pin OUTA is connected to the output end of the op amp unit.

[0060] In this embodiment, the operational amplifier chip is a dual-channel operational amplifier that can process two audio signals at the same time. In one of the audio signals, the first input end of the operational amplifier unit receives the first audio signal SPK_L+ without a static bias voltage after voltage division and filtering output by the audio recovery module, and is connected to the operational amplifier input positive pin INA+ of the operational amplifier chip through the third voltage-dividing resistor R3. The operational amplifier input positive pin INA+ of the operational amplifier chip is then connected to the ground terminal through the fourth voltage-dividing resistor R4. The second input end of the operational amplifier unit receives the second audio signal AUD_L+ with a static bias voltage output by the signal receiving module, and is connected to the operational amplifier input negative pin INA- of the operational amplifier chip through the fifth voltage-dividing resistor R5. The operational amplifier input positive pin INA+ of the operational amplifier chip is connected to the ground terminal through the fourth voltage-dividing resistor R4. The negative input pin INA- is connected to the op amp output pin OUTA via a sixth voltage-divider resistor R6. The op amp output pin OUTA is connected to the output of the op amp unit. The subtraction circuit forms a subtractor in the form of an operational amplifier. The voltage value of the first audio signal SPK_L+ is subtracted from the voltage value of the second audio signal AUD_L+ to obtain a reference voltage, which serves as the audio chip's quiescent bias voltage AUD_ADC_L+. Similarly, for another audio signal, the quiescent bias voltage AUD_ADC_L- is calculated by inputting the first audio signal SPK_L- and the second audio signal AUD_L-. Each operational amplifier chip can perform calculations for two audio signals, so using two operational amplifiers, all four audio signals can be calculated.

[0061] Specifically, in the above embodiment, the signal comparison unit includes a control chip, which includes a first input pin, a second input pin and an output pin, wherein the first input pin is connected to the output end of the audio recovery module, the second input pin is connected to the output end of the op amp unit, and the output pin is connected to the input end of the recovery adjustment module.

[0062] In this embodiment, the first input pin of the control chip is connected to the audio recapture module and can receive four first audio signals output by the voltage divider filter unit of the audio recapture module in real time. Specifically, take the first audio signal SPK_L+ as an example. At the same time, the second input pin of the control chip is connected to the operational amplifier unit and can receive the static bias voltages of the four channels output by the operational amplifier unit in real time. Specifically, take the static bias voltage AUD_ADC_L+ as an example. The control chip can compare the first audio signal SPK_L+ with the static bias voltage AUD_ADC_L+ in real time. Specifically, the comparison result is obtained by comparing the voltage value of the first audio signal SPK_L+ and the numerical value of the static bias voltage AUD_ADC_L+. The comparison result is output to the recapture adjustment module in the form of a level signal through the output pin of the control chip, which serves as a basis for the recapture adjustment module to adjust the voltage divider resistor of the voltage divider filter unit in the audio recapture module. The level signal includes a high level 1 and a low level 0.

[0063] Furthermore, the recovery adjustment module includes a resistance adjustment unit, a first input end of the resistance adjustment unit is connected to the output end of the audio recovery module, a second input end of the resistance adjustment unit is connected to the output pin of the control chip, and the output end of the resistance adjustment unit is connected to the voltage divider filter unit of the audio recovery module.

[0064] In this embodiment, the resistance adjustment unit is connected to the audio recapture module to receive the first audio signal SPK_L+ output by the audio recapture module after voltage division and filtering. At the same time, the resistance adjustment unit is connected to the control chip to receive the comparison result output by the control chip, that is, the level signal, and generates an adjustment strategy based on the comparison result to adjust the resistance value of the voltage divider resistor in the voltage divider filter unit of the audio recapture module. By changing the parameters in the voltage divider filter unit, the first audio signal SPK_L+ output by the audio recapture module does not exceed the static bias voltage AUD_ADC_L+.

[0065] Furthermore, the resistance adjustment unit includes a multiple-select analog switch chip, which includes at least two input pins, a signal receiving pin and a ground pin, wherein each of the at least two input pins is connected to the output end of the audio recovery module through an adjustment resistor, and each adjustment resistor is respectively connected in parallel with the second voltage divider resistor R2 in the voltage divider filter unit, the signal receiving pin is connected to the output pin of the control chip, and the ground pin is connected to the ground end.

[0066] In this embodiment, if Figure 5As shown, the multi-select one analog switch chip uses an eight-select one analog switch chip. Each eight-select one analog switch chip processes the audio signal of one sampling channel. The eight-select one analog switch chip includes eight input pins IN0-IN7. The eight-select one analog switch chip is connected to the audio sampling module. That is, the first audio signal SPK_L+ is connected to the eight input pins IN0-IN7 of the eight-select one analog switch chip through the adjustment resistors R7-R14 corresponding to each input pin, and the ground pin of the multi-select one analog switch chip is connected to the ground terminal. When the eight-select one analog switch chip receives the level signal output by the control chip The multiple-select-one analog switch chip operates. After the first audio signal SPK_L+ is input, it is grounded through an adjustment resistor, thereby connecting each adjustment resistor R7-R14 in parallel with the second voltage-dividing resistor R2 in the voltage-dividing filter unit. The level signal received by the signal receiving pin controls the conduction of any one of the eight input pins IN0-IN7 in the eight-select-one analog switch chip, changes the voltage dividing ratio of the second voltage-dividing resistor R2, and ultimately adjusts the peak range of the first audio signal SPK_L+ so that the voltage value of the first audio signal SPK_L+ does not exceed the static bias voltage AUD_ADC_L+.

[0067] Furthermore, the output pins of the control chip include an enable control output pin and multiple chip select output pins, and the signal receiving pins of the multiple-select analog switch chip include an enable control input pin EN and multiple chip select input pins. The number of chip select output pins is equal to the number of chip select input pins, wherein the enable control output pin and the enable control input pin are connected, and the multiple chip select output pins are respectively connected one-to-one with the multiple chip select input pins.

[0068] In this embodiment, the enable control output pin of the control chip outputs the enable control signal L+SEL_EN, and sends the enable control signal L+SEL_EN to the enable control input pin EN of the multiple-select analog switch chip to control the normal working state of the multiple-select analog switch chip. The number of the multiple chip select input pins of the multiple-select analog switch chip and the multiple chip select output pins of the control chip are both three. The three chip select input pins of the multiple-select analog switch chip transmit the chip select signals L+_SEL0, L+_SEL1, and L+_SEL2, respectively, which are connected to the three chip select input pins S0-S2 of the multiple-select analog switch chip, and then realize the on and off of the eight input pins IN0-IN7 in the eight-select analog switch chip through the combination of level signals. For example, the level signal received by the IN0 input pin is 000, and the level signal received by the IN1 input pin is 000. The received level signal is 001, the level signal received by the IN2 input pin is 010, the level signal received by the IN3 input pin is 011, the level signal received by the IN4 input pin is 100, the level signal received by the IN5 input pin is 101, the level signal received by the IN6 input pin is 110, and the level signal received by the IN7 input pin is 111. Then, according to the conduction state of the input pins IN0-IN7, the voltage dividing ratio of the second voltage dividing resistor R2 is changed, and finally the peak range of the first audio signal SPK_L+ is adjusted.

[0069] Another aspect of the present invention provides an audio recapture amplitude adaptation method, which is applied to the above-mentioned audio recapture amplitude adaptation circuit, such as Figure 6 As shown, first, the audio re-collection module receives the original audio signal sent by the playback device, and performs voltage-dividing filtering on the original audio signal through the voltage-dividing filtering unit to output a first audio signal. Then, the signal receiving module receives the first audio signal, and performs echo cancellation on the first audio signal to obtain a second audio signal. Then, the signal amplitude comparison module receives the first audio signal and the second audio signal, and performs subtraction calculation based on the first audio signal and the second audio signal to obtain a reference voltage value. The first audio signal is compared based on the reference voltage value and the comparison result is output. Finally, the re-collection adjustment module receives the comparison result and adjusts the resistance value of the resistor in the voltage-dividing filtering unit based on the comparison result so that the voltage value of the first audio signal does not exceed the reference voltage value.

[0070] Taking the original audio signal SPK_IN_L+ output by the playback device as an example, the audio recapture module in the audio recapture amplitude adaptation circuit receives the original audio signal SPK_IN_L+ sent by the playback device, and performs voltage division filtering on the original audio signal SPK_IN_L+ through the voltage division filtering unit in the audio recapture module, outputs a first audio signal SPK_L+, and sends the first audio signal SPK_L+ to the signal receiving module, the signal amplitude comparison module and the recapture adjustment module respectively; the signal receiving module receives the first audio signal SPK_L+, performs echo cancellation on the first audio signal SPK_L+, and outputs a second audio signal AUD_L+ with a static bias voltage, and sends the second audio signal AUD_L+ to the signal receiving module. The first audio signal SPK_L+ is sent to the signal amplitude comparison module; the signal amplitude comparison module receives the first audio signal SPK_L+ and the second audio signal AUD_L+, and calculates according to the first audio signal SPK_L and the second audio signal AUD_L+ to obtain a reference voltage value AUD_ADC_L+, and compares the first audio signal SPK_L based on the reference voltage value AUD_ADC_L+ to obtain a comparison result and sends it to the sampling adjustment module in the form of a level signal; the sampling adjustment module receives the level signal and adjusts the resistance of the voltage divider resistor in the voltage divider filter unit based on the level signal to adjust the parameters of the voltage divider filter unit, so as to make the peak range of the first audio signal SPK_L+ not exceed the reference voltage value AUD_ADC_L+.

[0071] The above method ensures that regardless of whether the playback device connected to the audio recapture amplitude adaptation circuit is replaced or the audio chip is replaced, when the original audio signal or the reference voltage value changes, the audio recapture amplitude adaptation method provided by the present application can calculate the first audio signal output by the audio recapture module and the second audio signal output by the signal receiving module to obtain the reference voltage, and compare it with the first audio signal. According to the comparison result, the resistance value of the voltage divider resistor in the voltage divider filter unit in the audio recapture module is adjusted in time, so that the peak range of the audio signal voltage value output by the voltage divider filter unit does not exceed the reference voltage value, thereby avoiding damage to the audio chip or poor echo cancellation effect, and ensuring the stability of the audio recapture effect.

[0072] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An audio recollection amplitude adaptation circuit, characterized in that: The audio recollection amplitude adaptation circuit is connected to the output end of the playback device. The audio recollection amplitude adaptation circuit includes an audio recollection module, a signal receiving module, a signal amplitude comparison module and a recollection adjustment module. The audio recollection module includes a voltage divider filter unit, wherein: The first input end of the audio recollection module is connected to the output end of the playback device, the first output end of the audio recollection module is connected to the input end of the signal receiving module, the second output end of the audio recollection module is connected to the first input end of the signal amplitude comparison module, and the third output end of the audio recollection module is connected to the first input end of the recollection adjustment module; The output end of the signal receiving module is connected to the second input end of the signal amplitude comparison module, the output end of the signal amplitude comparison module is connected to the second input end of the re-collection adjustment module, and the output end of the re-collection adjustment module is connected to the voltage-dividing filter unit, wherein the re-collection adjustment module is used to adjust the resistance of the voltage-dividing resistor in the voltage-dividing filter unit so that the voltage value of the first audio signal output by the original audio signal output by the playback device after voltage-dividing filtering by the voltage-dividing filter unit does not exceed a reference voltage value, and the reference voltage value is obtained by subtracting the audio signals output by the audio re-collection module and the audio signals output by the signal receiving module; The voltage-dividing filter unit includes a first filter capacitor, a first voltage-dividing resistor, a second filter capacitor, a second voltage-dividing resistor and a third filter capacitor, wherein the input end of the voltage-dividing filter unit is connected to the output end of the playback device, the input end of the voltage-dividing filter unit is connected to the first end of the first filter capacitor, the second end of the first filter capacitor is connected to the first end of the first voltage-dividing resistor, the second end of the first voltage-dividing resistor is connected to the first end of the second filter capacitor, the second end of the second filter capacitor is connected to the ground end, and the second filter capacitor is connected to the second voltage-dividing resistor in parallel, the second end of the first voltage-dividing resistor is also connected to the first output end of the voltage-dividing filter unit, the first output end of the voltage-dividing filter unit is respectively connected to the input end of the signal amplitude comparison module and the input end of the recovery adjustment module; the second end of the first voltage-dividing resistor is connected to the first end of the third filter capacitor, the second end of the third filter capacitor is connected to the second output end of the voltage-dividing filter unit, and the second output end of the voltage-dividing filter unit is connected to the input end of the signal receiving module; The signal receiving module includes an audio chip and a bias power supply. The audio chip includes a signal input pin and a signal output pin. The signal input pin is connected to the output end of the bias power supply. The signal input pin of the audio chip is connected to the output end of the audio recovery module, and the signal output pin of the audio chip is connected to the input end of the signal amplitude comparison module.

2. The audio recovery amplitude adaptation circuit according to claim 1, characterized in that: The signal amplitude comparison module includes an operational amplifier unit and a signal comparison unit, wherein: The first input end of the operational amplifier unit is connected to the output end of the audio recollection module, the second input end of the operational amplifier unit is connected to the output end of the signal receiving module, and the output end of the operational amplifier unit is connected to the first input end of the signal comparison unit; The second input end of the signal comparison unit is connected to the output end of the audio recovery module, and the output end of the signal comparison unit is connected to the input end of the recovery adjustment module.

3. The audio recovery amplitude adaptation circuit according to claim 2, characterized in that: The operational amplifier unit includes a subtraction circuit and an operational amplifier chip, and the operational amplifier chip includes an operational amplifier input pin and an operational amplifier output pin, wherein: The first input end of the operational amplifier unit and the second input end of the operational amplifier unit are respectively connected to the operational amplifier input pin of the operational amplifier chip through the subtraction circuit, and the operational amplifier output pin of the operational amplifier chip is connected to the output end of the operational amplifier unit.

4. The audio recovery amplitude adaptation circuit according to claim 3, characterized in that: The subtraction circuit includes a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, and a sixth voltage-dividing resistor, and the operational amplifier input pin includes an operational amplifier input positive pin and an operational amplifier input negative pin, wherein, The first input terminal of the operational amplifier unit is connected to the operational amplifier input positive pin through the third voltage-dividing resistor, and the operational amplifier input positive pin is connected to the ground terminal through the fourth voltage-dividing resistor; The second input end of the operational amplifier unit is connected to the operational amplifier input negative pin through the fifth voltage-dividing resistor, the operational amplifier input negative pin is connected to the operational amplifier output pin through the sixth voltage-dividing resistor, and the operational amplifier output pin is connected to the output end of the operational amplifier unit.

5. The audio recovery amplitude adaptation circuit according to claim 2, characterized in that: The signal comparison unit includes a control chip, and the control chip includes a first input pin, a second input pin and an output pin, wherein: The first input pin is connected to the output end of the audio recovery module, the second input pin is connected to the output end of the operational amplifier unit, and the output pin is connected to the input end of the recovery adjustment module.

6. The audio recovery amplitude adaptation circuit according to claim 5, characterized in that: The recovery adjustment module includes a resistance adjustment unit, a first input end of the resistance adjustment unit is connected to the output end of the audio recovery module, a second input end of the resistance adjustment unit is connected to the output pin of the control chip, and the output end of the resistance adjustment unit is connected to the voltage divider filter unit of the audio recovery module.

7. The audio recovery amplitude adaptation circuit according to claim 6, characterized in that: The resistance adjustment unit includes a multiple-choice analog switch chip, and the multiple-choice analog switch chip includes at least two input pins, a signal receiving pin and a ground pin, wherein: Each of the at least two input pins is connected to the output end of the audio recovery module through an adjustment resistor, and each of the adjustment resistors is connected in parallel with the second voltage divider resistor in the voltage divider filter unit, the signal receiving pin is connected to the output pin of the control chip, and the ground pin is connected to the ground end.

8. The audio recovery amplitude adaptation circuit according to claim 7, characterized in that: The output pins of the control chip include an enable control output pin and a plurality of chip select output pins, the signal receiving pins of the multiple-select-one analog switch chip include an enable control input pin and a plurality of chip select input pins, and the number of the chip select output pins is equal to the number of the chip select input pins, wherein, The enable control output pin is connected to the enable control input pin, and the multiple chip select output pins are respectively connected to the multiple chip select input pins in a one-to-one correspondence.

9. An audio recollection amplitude adaptation method, characterized in that: The method is applied to the audio recovery amplitude adaptation circuit according to any one of claims 1 to 8, and the method comprises: The audio recollection module receives the original audio signal sent by the playback device, performs voltage division filtering on the original audio signal through the voltage division filtering unit, and outputs a first audio signal; The signal receiving module receives the first audio signal and performs echo cancellation on the first audio signal to obtain a second audio signal; The signal amplitude comparison module receives the first audio signal and the second audio signal, performs a subtraction calculation based on the first audio signal and the second audio signal to obtain a reference voltage value, compares the first audio signal based on the reference voltage value, and outputs a comparison result; The sampling adjustment module receives the comparison result and adjusts the resistance value of the resistor in the voltage-dividing filter unit based on the comparison result so that the voltage value of the first audio signal does not exceed the reference voltage value.

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