Automatic correction amplifying circuit

Abstract

The utility model relates to the technical field of audio amplification, and discloses an automatic correction amplification circuit capable of reducing noise, which comprises a signal amplification module (110) and a correction amplification module (120), and the signal amplification module (110) is used for receiving a first audio signal and amplifying the first audio signal to output a second audio signal. A difference signal obtained after the first audio signal and the second audio signal are superposed is input into the correction amplification module (120), and an error correction signal is obtained after the difference signal is processed by the correction amplification module (120).

Description

TECHNICAL FIELD

[0001] The utility model relates to audio frequency amplification technical field, more specifically, relate to an automatic correction amplification circuit. BACKGROUND

[0002] Audio amplifiers are widely used in various applications. For example, audio amplifiers are commonly used in music devices, computers, televisions, telephones, etc., and listeners of such devices generally prefer high quality audio output.

[0003] At present, the traditional amplifier does not have distortion correction function, can only reduce distortion from component selection, DC operating point setting and negative feedback circuit, especially for audio power amplifier, even if strict component selection and fine adjustment of DC operating point and setting reasonable negative feedback, but the distortion is still difficult to be less than -90dB (0.003%); On the other hand, the traditional amplifier does not have the function of eliminating the noise generated when the amplifier works, and the noise threshold circuit used in the industry can eliminate the noise of the amplifier by setting a certain level threshold, which not only cannot eliminate the noise generated when the amplifier works, but also causes obvious attenuation to weak signals, resulting in loss of music details. SUMMARY

[0004] The technical problem to be solved by the utility model is that the above-mentioned traditional amplifier of the prior art does not have distortion correction and eliminates the noise generated when the amplifier works, resulting in high distortion of audio signals and obvious attenuation to weak signals, resulting in loss of music details, and provides an automatic correction amplification circuit capable of noise reduction.

[0005] The utility model adopts the technical scheme in the technical problem: construct an automatic correction amplification circuit, have:

[0006] Signal amplification module, it is configured in the amplification circuit, an input end is connected with the output end of signal source, for receiving first audio signal, and the first audio signal is amplified to output second audio signal;

[0007] Correction amplification module, an input end is connected with the output end of signal source, for receiving the first audio signal,

[0008] The input end of the correction amplification module is also connected with the output end of the signal amplification module, for receiving the second audio signal,

[0009] The output end of the correction amplification module is connected with another input end of the signal amplification module,

[0010] The difference signal obtained by superimposing the first audio signal and the second audio signal is input into the correction amplification module, and an error correction signal is obtained after processing by the correction amplification module.

[0011] In some embodiments, the signal amplification module at least includes a first resistor, a first operational amplifier, and an audio power amplifier,

[0012] One end of the first resistor is connected to the output end of the signal source for receiving the first audio signal,

[0013] The non-inverting input end of the first operational amplifier is connected to the other end of the first resistor,

[0014] The inverting input end of the first operational amplifier is connected to the other end of the first resistor,

[0015] The inverting input end of the first operational amplifier is connected to the other end of the first resistor,

[0016] The output end of the audio power amplifier is connected to the load and an input end of the correction amplification module, respectively.

[0017] In some embodiments, the signal amplification module further includes a second resistor and a third resistor,

[0018] One end of the second resistor is connected to the output end of the first operational amplifier,

[0019] The other end of the second resistor is connected to one end of the third resistor,

[0020] The other end of the third resistor is connected to the non-inverting input end of the first operational amplifier.

[0021] In some embodiments, the correction amplification module at least includes a second operational amplifier, a fourth resistor, and a sixth resistor,

[0022] One end of the fourth resistor is connected to the output end of the signal source for receiving the first audio signal,

[0023] One end of the sixth resistor is coupled to the output end of the audio power amplifier for receiving the second audio signal,

[0024] The non-inverting input end of the second operational amplifier is connected to the other end of the fourth resistor and the sixth resistor, respectively,

[0025] The output end of the second operational amplifier is connected to the inverting input end of the first operational amplifier.

[0026] In some embodiments, the correction amplification module further comprises a fifth resistor,

[0027] One end of the fifth resistor is connected with the output end of the second operational amplifier,

[0028] The other end of the fifth resistor is connected with the inverting input end of the second operational amplifier.

[0029] In some embodiments, the ratio of the sixth resistor to the fourth resistor is equal to the ratio of the third resistor to the first resistor.

[0030] In some embodiments, the level of the second audio signal is the same as and opposite in phase to the level of the first audio signal.

[0031] In some embodiments, after the second audio signal and the first audio signal are superimposed at the inverting input end of the second operational amplifier, they cancel each other to obtain a zero potential, so as to output the error correction signal.

[0032] In some embodiments, the first operational amplifier suppresses the same signal part in the input error correction signal and the first audio signal, and amplifies the different signal part in the signals at the two input ends.

[0033] In the automatic correction amplification circuit, the signal amplification module is used for receiving a first audio signal and amplifying the first audio signal to output a second audio signal, and the correction amplification module is used for receiving a difference signal obtained by superimposing the first audio signal and the second audio signal, and processing the difference signal to obtain an error correction signal. Compared with the prior art, the correction amplification module can reduce signal distortion and noise generated by the circuit, can automatically adjust and correct the midpoint direct current point of the amplifier output, can reduce the distortion degree of the signal, and can improve the tone of the audio signal. BRIEF DESCRIPTION OF DRAWINGS

[0034] The utility model will be further described in connection with the drawings and examples, in the drawings:

[0035] Figure 1 It is the circuit principle drawing of one embodiment of automatic correction amplification circuit provided by the utility model. DETAILED DESCRIPTION

[0036] In order to have more clear understanding of the technical features, objects and effects of the utility model, the specific implementation mode of the utility model will be described in detail by comparing the drawings.

[0037] As Figure 1As shown, in the first embodiment of the automatic correction amplification circuit of the utility model, the automatic correction amplification circuit comprises a signal amplification module 110 and a correction amplification module 120,

[0038] The signal amplification module 110 has the functions of signal receiving and amplification,

[0039] The correction amplification module 120 is used for receiving the multi-channel input or feedback audio signal, outputting the first audio signal obtained from the signal source (corresponding to V1) and the second audio signal output from the signal amplification module 110, superimposing the first audio signal and the second audio signal, obtaining the difference signal, and obtaining the error correction signal containing distortion, noise, or DC offset component after the difference signal is inverted by the correction amplification module 120;

[0040] Specifically, the signal amplification module 110 is configured in the amplification circuit, one input end of which is connected with the output end of the signal source (corresponding to V1), used for receiving the first audio signal output from the signal source (corresponding to V1), and amplifying the input first audio signal to output the second audio signal to the power amplifier or load;

[0041] Further, one input end of the correction amplification module 120 is connected with the output end of the signal source (corresponding to V1), used for receiving the first audio signal output from the signal source (corresponding to V1),

[0042] One input end of the correction amplification module 120 is also connected with the output end of the signal amplification module 110, used for receiving the second audio signal output from the signal amplification module 110,

[0043] The output end of the correction amplification module 120 is connected with the other input end of the signal amplification module 110,

[0044] The difference signal obtained after the superposition of the first audio signal and the second audio signal is input into the correction amplification module 120, and an error correction signal is obtained after the processing of the correction amplification module 120.

[0045] By setting the correction amplification module 120, the signal distortion and noise generated by the circuit can be reduced, the midpoint DC point of the amplifier output can be automatically adjusted and corrected, the distortion degree of the signal can be reduced, and the tone of the audio signal can be improved.

[0046] In some embodiments, in order to improve the quality of the output audio signal, a first resistor R101, a first operational amplifier U101 and an audio power amplifier AMP can be arranged in the signal amplification module 110,

[0047] The first operational amplifier U101 is used as a small signal voltage amplification stage,

[0048] The audio power amplifier AMP is used as a power amplification stage in the circuit,

[0049] The first resistor R101 is an input resistor of the first operational amplifier U101.

[0050] Specifically, one end of the first resistor R101 is connected to an output terminal of a signal source (corresponding to V1) for receiving a first audio signal output by the signal source (corresponding to V1),

[0051] The other end of the first resistor R101 is connected to an inverting input terminal (corresponding to pin 4) of the first operational amplifier U101.

[0052] The non-inverting input terminal (corresponding to pin 5) of the first operational amplifier U101 is connected to an output terminal of the correction amplification module 120, and the first audio signal is amplified and output as a second audio signal.

[0053] The output terminal (corresponding to pin 6) of the first operational amplifier U101 is connected to an input terminal (corresponding to pin 7) of the audio power amplifier AMP.

[0054] The output terminal (corresponding to pin 8) of the audio power amplifier AMP is connected to a load (corresponding to SPK) and an input terminal of the correction amplification module 120, respectively. The second audio signal amplified by the audio power amplifier AMP is input to the load (corresponding to SPK), and is further fed back to the input terminal of the correction amplification module 120 through the sixth resistor R106.

[0055] In some embodiments, in order to improve the amplification effect of the first operational amplifier U101 on the signal, a second resistor R102 and a third resistor R103 can be arranged in the signal amplification module 110.

[0056] The second resistor R102 is a local feedback resistor of the power amplification part.

[0057] The third resistor R103 is a feedback resistor of the first operational amplifier U101, and the gain thereof is -R103 / R101.

[0058] Specifically, one end of the second resistor R102 is connected to the output terminal (corresponding to pin 6) of the first operational amplifier U101 for receiving the first audio signal output by the first operational amplifier U101 after amplification.

[0059] The other end of the second resistor R102 is connected to one end of the third resistor R103.

[0060] The other end of the third resistor R103 is connected to the inverting input terminal (corresponding to pin 5) of the first operational amplifier U101, and the amplified first audio signal is input to the first operational amplifier U101 through the second resistor R102 and the third resistor R103.

[0061] In some embodiments, in order to ensure the correction effect on the input signal, a second operational amplifier U102, a fourth resistor R104 and a sixth resistor R106 can be arranged in the correction amplification module 120,

[0062] The second operational amplifier U102 has a signal correction and amplification function,

[0063] The fourth resistor R104 is an input resistor,

[0064] The sixth resistor R106 is a loop feedback sampling resistor of the second operational amplifier U102.

[0065] Specifically, one end of the fourth resistor R104 is connected to the output end of the signal source (corresponding to V1) for receiving the first audio signal,

[0066] One end of the sixth resistor R106 is coupled to the output end (corresponding to 8 pins) of the audio power amplifier AMP for receiving the second audio signal output by the audio power amplifier AMP,

[0067] The non-inverting input end (corresponding to 2 pins) of the second operational amplifier U102 is connected to the other end of the fourth resistor R104 and the sixth resistor R106 respectively,

[0068] The non-inverting input end (corresponding to 3 pins) of the second operational amplifier U102 is connected to the common end,

[0069] The output end (corresponding to 1 pin) of the second operational amplifier U102 is connected to the non-inverting input end (corresponding to 5 pins) of the first operational amplifier U101.

[0070] In some embodiments, the correction amplification module 120 further comprises a fifth resistor R105, wherein the fifth resistor R105 is a local feedback resistor of the second operational amplifier U102,

[0071] Specifically, one end of the fifth resistor R105 is connected to the output end (corresponding to 1 pin) of the second operational amplifier U102,

[0072] The other end of the fifth resistor R105 is connected to the non-inverting input end (corresponding to 2 pins) of the second operational amplifier U102.

[0073] The ratio of the sixth resistor R106 to the fourth resistor R104 is equal to the ratio of the third resistor R103 to the first resistor R101.

[0074] In some embodiments, the level of the second audio signal is the same as that of the first audio signal and the phase is opposite.

[0075] In some embodiments, the second audio signal and the first audio signal are superimposed at the inverting input terminal of the second operational amplifier U102, and cancel each other to obtain a zero potential, so as to output the error correction signal.

[0076] In some embodiments, the first operational amplifier U101 suppresses the same signal part in the input error correction signal and the first audio signal, and amplifies the different signal part in the two input signals.

[0077] Specifically, Figure 1 In some embodiments, the direction indicated by the arrow 1-11 is the signal flow direction of each signal flow branch in the operational amplifier circuit.

[0078] Figure 1 In some embodiments, A-E represent each signal flow node in the amplifier.

[0079] Signal amplification process of the operational amplifier:

[0080] The AC signal output by the V1 signal source reaches the signal flow node A through the signal flow branch 1, reaches the signal flow node B through the signal flow branch 2 and the first resistor R101, is input to the inverting input terminal of the first operational amplifier U101 through the signal flow branch 3 from the signal flow node B, is amplified by the first operational amplifier U101, is sent to the input terminal of the audio power amplifier AMP through the signal flow branch 4 from the signal flow node C, is output from the signal flow node D after being amplified by the audio power amplifier AMP, and reaches the loudspeaker SPK through the signal flow branch 11.

[0081] Feedback signal flow process of the operational amplifier:

[0082] The signal output from the signal flow node D after being amplified by the first operational amplifier U101 reaches the signal flow node C through the signal flow branch 5 and the feedback resistor R2, and is sent to the input terminal of the audio power amplifier AMP through the signal flow branch 4 to complete the feedback of the power amplifier and realize the gain adjustment of the power amplifier stage.

[0083] The signal output from the signal flow node D after being amplified by the first operational amplifier U101 reaches the signal flow node B through the signal flow branch 6 and the third resistor R103, and is input to the input terminal of the first operational amplifier U101 through the signal flow branch 3 to complete the loop feedback of the signal link of the first operational amplifier U101.

[0084] The first audio signal flowing into the first operational amplifier U101 through the first resistor R101 does not produce a voltage drop across the first resistor R101, so that the potential of the signal flow node A in the circuit is the same as that of the signal flow node B. Similarly, the signal flowing into the second operational amplifier U102 through the fourth resistor R104 does not produce a voltage drop across the fourth resistor R104, so that the potential of the signal flow node A in the circuit is the same as that of the signal flow node E, i.e. the potentials of the signal flow nodes A, B and E are equal.

[0085] Signal flow and correction principle of the second operational amplifier U102 (or correction amplifier):

[0086] The first audio signal (or AC signal) output by the signal source (corresponding to V1) reaches the signal flow node A through the signal flow branch 1, and then reaches the signal flow node E through the signal flow branch 7 and the fourth resistor R104. This signal serves as the reference signal of the signal source (corresponding to V1), and has the same phase and signal amplitude as the signal source.

[0087] Meanwhile, the amplified signal output from the first operational amplifier U101 is output through the signal flow node D and reaches the signal flow node E through the signal flow branch 9 and the sixth resistor R106 as a sampled signal together with the reference signal of the signal source (corresponding to V1). Since the first operational amplifier U101 adopts an inverting amplification circuit architecture, the phase of the sampled signal of the signal flow branch 9 is opposite to that of the signal source (corresponding to V1).

[0088] The resistance values of the sixth resistor R106 and the fourth resistor R104 can be determined by the ratio of the sixth resistor R106 / the fourth resistor R104 = the third resistor R103 / the first resistor R101, which makes the sampled level obtained at the signal flow node E in the circuit and the reference level of the signal source (corresponding to V1) have the same size and opposite phase. The two signals with the same size and opposite phase cancel each other out to obtain a zero potential after being superimposed at the signal flow node E.

[0089] When the first operational amplifier U101 generates distortion, noise, or the output terminal direct current potential is offset, the output terminal D node of the first operational amplifier U101 will contain additional signal components other than the first audio signal output by the signal source (corresponding to V1), and the composite signal containing the first audio signal and the additional signal components is fed back to the signal flow node E through the sixth resistor R106, and the reference signal of the signal source (corresponding to V1) obtained at the signal flow node E is superimposed to obtain a difference signal, the difference signal is sent to the inverting input terminal of the second operational amplifier U102 through the signal flow branch 8, and a correction signal containing distortion, noise, or direct current offset component is obtained after being inverted by the second operational amplifier U102 and output from the signal flow node F, and then sent to the non-inverting input terminal of the first operational amplifier U101 through the signal flow branch 11, and since R106 / R104=R103 / R101, the signal of the signal source (corresponding to V1) input to the inverting input terminal of the first operational amplifier U101 and the error correction signal input to the non-inverting input terminal of the first operational amplifier U101 have the same gain obtained on the first operational amplifier U101.

[0090] And the first operational amplifier U101 uses a differential amplifier circuit connection method, since the differential amplifier has a very high common mode rejection ratio characteristic, the first operational amplifier U101 will suppress the same signal part in the signals input to the two input terminals of the first operational amplifier U101, and amplify the different signal part in the signals of the two input terminals, thereby the error correction signal input through the non-inverting input terminal of the first operational amplifier U101 is amplified after the main amplifier, and a correction output signal equal in size but opposite in phase to the original additional signal is output on the output terminal D node of the first operational amplifier U101, and the original additional signal is offset to obtain a pure amplified signal source signal.

[0091] The embodiments of the utility model are described above in combination with the drawings, but the utility model is not limited to the specific implementation manners described above, the specific implementation manners described above are only illustrative, but not restrictive, and the person skilled in the art can make many forms under the inspiration of the utility model without departing from the purpose of the utility model and the scope protected by the claims, and these all belong to the protection of the utility model.

Claims

1. An auto-correcting amplification circuit, characterized by, Possessing: A signal amplification module is configured in the amplification circuit, one input end is connected with the output end of the signal source, used for receiving the first audio signal, and the first audio signal is amplified to output the second audio signal; The correction amplification module is connected with the output end of the signal amplification module, used for receiving the second audio signal, The output end of the correction amplification module is connected with the other input end of the signal amplification module, The difference signal obtained after the first audio signal and the second audio signal are superimposed is input into the correction amplification module, and an error correction signal is obtained after the correction amplification module is processed.

2. The automatic correction amplification circuit according to claim 1, wherein The signal amplification module at least includes a first resistor, a first operational amplifier and an audio power amplifier, One end of the first resistor is connected with the output end of the signal source, used for receiving the first audio signal, The non-inverting input end of the first operational amplifier is connected with the other end of the first resistor, The inverting input end of the first operational amplifier is connected with the output end of the correction amplification module, The input end of the audio power amplifier is connected with the output end of the first operational amplifier, The output end of the audio power amplifier is connected with the load and one input end of the correction amplification module respectively.

3. The automatic correction amplification circuit according to claim 2, wherein The signal amplification module further includes a second resistor and a third resistor, One end of the second resistor is connected with the output end of the first operational amplifier, The other end of the second resistor is connected with one end of the third resistor, The other end of the third resistor is connected with the non-inverting input end of the first operational amplifier.

4. The automatic correction amplification circuit according to claim 3, wherein The correction amplification module at least includes a second operational amplifier, a fourth resistor and a sixth resistor, One end of the fourth resistor is connected with the output end of the signal source, used for receiving the first audio signal, One end of the sixth resistor is coupled to the output end of the audio power amplifier, used for receiving the second audio signal, The non-inverting input end of the second operational amplifier is connected with the other end of the fourth resistor and the sixth resistor respectively, The output end of the second operational amplifier is connected with the inverting input end of the first operational amplifier.

5. The automatic correction amplification circuit according to claim 4, wherein The correction amplification module further includes a fifth resistor, One end of the fifth resistor is connected with the output end of the second operational amplifier, The other end of the fifth resistor is connected with the non-inverting input end of the second operational amplifier.

6. The automatic correction amplification circuit according to claim 5, wherein The ratio of the sixth resistor to the fourth resistor is equal to the ratio of the third resistor to the first resistor. ​ 7. The auto-correcting amplifier circuit of claim 5, wherein, the second audio signal has the same amplitude and opposite phase of the first audio signal.

8. The auto-correcting amplifier circuit of claim 7, wherein, the second audio signal and the first audio signal cancel each other out to zero potential after being superimposed at the inverting input of the second operational amplifier to output the error correction signal.

9. The auto-correcting amplifier circuit of claim 8, wherein, the first operational amplifier suppresses the same signal portions of the error correction signal and the first audio signal and amplifies the different signal portions of the two inputs.

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