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iPhone camera circuit repairing

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This video mainly explains the front camera working principle of the iPhone XR to iPhone XS Max models

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The principles of these three models are the same

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Working principle step 1, after triggering the switch,

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the main power supply will output many power supplies,

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among which the 1.8V power supply will first provide the working voltage for the front camera

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Step 2, after the CPU working condition is normal,

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it will detect the front camera through the I2C bus

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Step 3, after the CPU detects the camera, it sends a clock signal to the camera

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Step 4, when starting to the camera circuit,

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the camera power supply provides 2.85V and 1.1V power supply to the front camera

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Step 5, when starting to the camera circuit,

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the CPU sends an open signal to the front camera

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When starting to the camera circuit, the current is generally around 1A

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After entering the system, the CPU will control the camera power supply,

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turn off the 2.85V and 1.1V power supplies,

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and turn off the open signal of the front camera,

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and the front camera will not work at this time

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The advantage of this design is that it can save power

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Step 6, when we use the camera function, click the camera icon

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The CPU will control the camera power supply,

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so that the camera power supply will output the 2.85V and 1.1V power supply of the front camera again

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After the power supply is output, the CPU sends an open signal to the front camera

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After the camera has working conditions, it starts to collect image information

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The camera will send the collected image information to the CPU through the LPDP bus

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After the CPU receives the data, it will display the information on the screen

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When we click the camera button, the CPU will intercept the current LPDP bus data

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and transfer it to the hard disk to complete the camera function

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When we click the recording function,

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the CPU will continuously transfer the LPDP bus data to the hard disk

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When we press stop, the CPU no longer collects LPDP bus data,

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and the video recording is completed

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In the functional block diagram,

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LPDP_AUX is the LPDP bus data detection signal from the CPU to the front camera

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If there is a working condition in the block diagram that is not normal,

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it will cause the front camera to fail to open

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That's all for this video