Audio switching circuit and mobile terminal with same

Abstract

The invention discloses an audio switching circuit and a mobile terminal with the same. The audio switching circuit comprises a single-pole double-throw analog switch for switching and outputting audio signals output through a square wave audio channel and an analog audio channel; the public node of the single-pole double-throw analog switch in the audio switching circuit is connected with the analog audio channel, one path of movable contact is grounded through a resistor, the other path of movable contact is connected with the input end of a loudspeaker through a series stopping condenser, and the input end of the loudspeaker is simultaneously connected with the square wave audio channel; and the square wave audio channel is closed when the analog audio channel outputs audio signals. The analog switch is used reversely; and when the audio signals in a square wave form are output, the signals coupled to the analog audio channel are skillfully released to the ground through a grounding resistor so as to realize effective isolation of square wave audio signals and analog audio signals and prevent a baseband processing chip and the analog switch from being burnt out.

Description

technical field [0001] The invention belongs to the technical field of audio signal processing, and in particular relates to a selection switching circuit for multi-channel audio signals and a mobile terminal designed using the audio switching circuit. Background technique [0002] With the development of mobile communication technology, the baseband processing chips of mobile phones are also developing in the direction of small size, high integration, low power consumption and high performance. In terms of mobile phone audio, due to the high conversion efficiency of Class D audio power amplifiers, the system power consumption is effectively reduced, and now it has become the mainstream of various mobile phone platform applications. Now the baseband processing chips of mainstream mobile phone platforms integrate Class D audio power amplifiers into them to reduce customer development costs, enhance system reliability, and reduce power consumption. For example, Qualcomm's QSC...

AI Technical Summary

Problems solved by technology

[0005] For the audio switching circuit scheme designed with digital switches, although the digital switch can effectively isolate the square wave signal from the Class D audio power amplifier, the biggest disadvantage is that the on-resistance of this switch is extremely large, which will cause problems in practical applications. Generate unnecessary loss on the digital switch, and even burn the digital switch

Therefore, there are technical safety hazards and the reliability is not high

For the audio switching circuit scheme designed with two analog switches, since the analog switch cannot effectively isolate the square wave signal output by the class D power amplifier similar to the digital signal, it can effectively isolate the analog signal output by the earpiece channel.

Therefore, when the speaker channel is sounding, there will be an audio signal coupled to the earpiece channel, which will affect

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