Audio interface circuit, circuit group, automobile and audio access method

Abstract

The invention discloses an audio interface circuit, and the circuit comprises an input end, a main output end, an auxiliary output end, a first filtering module, a first conversion module, a second filtering module and a second conversion module. The first filtering module is used for filtering the differential signal accessed from the input end and outputting the differential signal to the firstconversion module; the first conversion module converts the signal into a first common-mode signal and outputs the first common-mode signal to the second filtering module; the first conversion moduleoutputs the first common-mode signal through the main output end; the second filtering module filters the first common-mode signal to obtain a second common-mode signal, and outputs the second common-mode signal to the second conversion module; and the second conversion module converts the second common-mode signal into a differential signal and outputs the differential signal through the auxiliary output end. The invention also discloses an audio interface circuit group, an automobile and an audio access method, which can effectively improve the signal quality of the same sound source sharedby multiple paths of vehicle-mounted equipment.

Description

technical field [0001] The invention relates to the field of car audio equipment, in particular to an audio interface circuit, a circuit group, a car and an audio access method. Background technique [0002] With the development of market demand, the interactive functions of cars are becoming more and more abundant, and the car microphone has become a standard electrical appliance. [0003] A plurality of ECUs (Electronic Control Unit, electronic control unit) of automobile configuration often needs to share one microphone sound source at present, as the bluetooth telephone of vehicle-mounted entertainment head unit and the ECALL / BCALL of TBOX, and in the process of implementing the present invention, the inventor finds that There are at least the following problems in the technology: [0004] 1. Due to the inconsistency of the microphone interface circuits at each ECU end, there are inconsistent bias voltages and inconsistent ground planes, each ECU causes crosstalk or EMC...

AI Technical Summary

Problems solved by technology

[0004] 1. Due to the inconsistency of the microphone interface circuits at each ECU end, there are inconsistent bias voltages and inconsistent ground planes, each ECU causes crosstalk or EMC quality deterioration through the negative ground loop of the microphone;

[0005] 2. Since it can only be output in the form of non-differential signals, the body wiring harness is susceptible to external interference, which affects the quality of the signal

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