Active noise reduction system, adaptive calibration analog filter circuit and earphone

Abstract

The invention relates to an active noise reduction system, an adaptive calibration analog filter circuit and an earphone. The active noise reduction system comprises a microphone used for collecting environmental noise to generate a first audio signal; the first chip is used for preprocessing the first audio signal; an analog filter circuit and a second chip, at least part of the analog filter circuit is integrated on the second chip, and the analog filter circuit is used for carrying out filtering processing on the preprocessed first audio signal to form a de-noising signal with a phase opposite to that of the environment noise; the first chip is also used for receiving a second audio signal comprising the target audio, and mixing the second audio signal with the de-noising signal to forma mixed audio signal; and the loudspeaker is used for playing the mixed audio signal. According to the scheme, the number of devices installed on the circuit board is small, the space of the circuitboard is saved, product miniaturization can be achieved, parasitic parameters are reduced, time delay and power consumption can be reduced, and the signal-to-noise ratio can be increased.

Description

technical field [0001] The invention relates to the technical field of earphones, in particular to an active noise reduction system, an adaptively calibrated analog filter circuit and earphones. Background technique [0002] Active noise cancellation (Active Noise Cancellation, ANC) is to generate a sound wave with a phase opposite to that of the external noise through the noise reduction system, so as to completely cancel the noise, thereby achieving the effect of noise reduction. Active noise reduction technology can be applied to headphones. The active noise reduction system of the existing earphones has many devices installed on the circuit board, which is prone to the problem that the product performance is affected by the deviation of the devices on the circuit board during production, and the volume is large, which is not conducive to the miniaturization of the product. Contents of the invention [0003] The purpose of the present invention is to provide an active ...

AI Technical Summary

Problems solved by technology

The active noise reduction system of the existing earphones has many devices installed on the circuit board, which is prone to the problem that the product performance is affected by the deviation of the devices on the circuit board during production, and the volume is large, which is not conducive to the miniaturization of the product

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