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This lesson talks about the relevant circuits of MediaTek's microphones

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Take Redmi K50 as an example, it uses the MediaTek platform

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Let's first look at what components are in this circuit

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This circuit has one more headphone microphone than HiSilicon's platform

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There is a description of the three microphones in this circuit

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The first is the microphone, and J6501 is the socket on the mainboard that connects to the tail plug

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There is also a microphone for the headset, which is connected to the seat J6502

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There is also a secondary microphone, which is the microphone on the top of the phone.

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This microphone is directly named after the position number of the microphone,

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the position number is U6002

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This is the secondary microphone

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This is the main microphone

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This is the microphone connector

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The signal of the microphone passes through this seat,

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and is connected to the small board of the tail plug through the cable

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There is a microphone on the small board of the tail plug, this is the main microphone

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We found the main microphone, secondary microphone and headset microphone,

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and then look at the power chip

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Most MediaTek power chips contain a large audio

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This power chip is called MT6368

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This power chip contains an audio chip inside, which is the power

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Look at the CPU

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The large audio chip inside the power chip communicates with the CPU

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The bus that transmits audio signals is relatively simple

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It is named after AUD, which is the abbreviation of audio, and DAT is data

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MISO is the master input slave output, the arrow here is wrongly marked

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OUT is the output, here is the master output slave input

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These are the two wires, one is input and the other is output

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There are usually three groups of input and output data lines, 0, 1, 2

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This is the communication bus between the CPU and the big audio contained inside the power supply

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Let's take a look at its workflow

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For example, when recording, after the main microphone is powered by BIAS,

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we talk to it, it converts the sound into an electrical signal,

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and the signal is sent to the large audio inside the power supply

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The big audio amplifies the analog signal, and after analog-to-digital conversion processing,

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it is finally sent to the CPU through the MISO data bus

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The CPU then adjusts its functions according to the actual situation

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If it is a recording, it will store the sound

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If the hands-free call is not turned on,

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the main microphone sends the sound signal to the baseband and radio frequency

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By observing this line, we found that it is similar to the pin of the microphone on the Hisilicon platform.

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It has input signals

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This VIN is the input, AUD refers to the audio

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BIAS is the power supply for the microphone

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The above is the microphone circuit of MediaTek.

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The bus is a bit different from that of HiSilicon.

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It contains a large audio in the power supply

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HiSilicon has a separate large audio, and the others are almost the same

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That's all for this lesson