Circuit for improving separation degree of each sound channel of analog audio interface and audio system

Abstract

The invention relates to a circuit for improving the separation degree of each sound channel of an analog audio interface and an audio system. The circuit comprises an internal audio circuit of an earphone interface chip and an external related interface circuit, wherein the internal audio circuit of the earphone interface chip comprises a power amplifier driving circuit and analog switches Rsw1-Rsw8; the reference ground of the power amplifier driving circuit and the reference ground of the MICBIAS decoupling capacitor C3 are connected to an off-chip position close to an earphone interface through an analog switch; and after the earphone type is determined, establishing a connection relationship with the off-chip circuit by configuring the states of the on-chip analog switches Rsw1-Rsw8 according to the earphone type so as to realize correct electrical connection. According to the invention, by optimizing the internal audio circuit and the external related interface circuit of the earphone interface chip, the separation degree between the left and right sound channels of the loudspeaker and the separation degree between the loudspeaker and the microphone can be effectively improved, the sidetone is improved, and the playing and call quality is improved.

Description

technical field [0001] The invention relates to the technical field of audio transmission, in particular to a circuit and an audio system for improving the separation degree of each channel of an analog audio interface. Background technique [0002] The 3.5mm headphone connector in the prior art can be divided into two standards: OMTP and CTIA according to the order of pin definition. The two standards are different in the definition of pins. The specific definitions and differences are as follows. figure 1 shown. With the development of electronics and integrated circuits, in order to take into account the headphones of different standards, the current terminal equipment mainly realizes the type identification of the headphones through an integrated single chip and realizes the correct electrical connection through the internal semiconductor switch. The on-chip structure diagram of the existing conventional headphone adapter chip is as follows figure 2 shown. The on-chi...

AI Technical Summary

Problems solved by technology

As for the crosstalk between the speaker and the Microphone, a performance scenario is that when one party uses a headphone interface chip with a crosstalk problem when making a call with someone else, on the one hand, it will allow the other party to hear what they are saying. Since it is not necessary, it can be called Noise, this kind of noise mixed with your own voice will also reduce the clarity of the call, and in severe cases will interfere with its normal call

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