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This lesson talks about the relevant circuits of the microphone on the Qualcomm platform

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Taking the Xiaomi 11 model as an example, first look at the components in this circuit

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First is the main microphone, which leads to the socket J6502

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The main microphone is usually on the small board of the tail plug

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The position number of the secondary microphone is U6004

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This is a big audio, codenamed CODEC or CDC

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It is a separate audio chip, and its position number on Xiaomi 11 is U5800

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Look at the CPU

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These two lines are used between the big audio and the CPU to transmit data

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This microphone circuit is very similar to HiSilicon's microphone circuit,

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the difference is that the bus is different

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The code names of the main body in the circuit are the same, for example,

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the power supply of the microphone is BIAS

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The difference is that there is an additional code of WCD and code of CDC

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WCD is a code name used by Qualcomm's niche range,

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which means that it only describes Qualcomm's audio

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Qualcomm's big audio model starts with WCD

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CDC also refers to the big audio

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CDC is the abbreviation of codec, which means that this signal leads to large audio

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WCD indicates that the power supply of this microphone comes from the big audio,

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which is related to the big audio

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Regardless of Qualcomm, HiSilicon, or Liantek, their circuits are almost exactly the same

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Maybe the audio chip of some models is included in the power chip

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This is the relevant circuit of the microphone

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Generally speaking, there are two microphones working,

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one is the main microphone and the other is the secondary microphone

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The line signal from the microphone is mostly handled by the loud audio

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We will learn the circuit of the small audio later,

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you will find that the signal of the microphone does not lead to the small audio

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Everyone must understand this logic

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The circuit logic of the microphone is that the microphone is connected to the big audio,

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and the big audio is connected to the CPU

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This is the simplest generalization

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That's all for this lesson