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The working principle of the iPhone standby circuit

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Before learning the principle, let's first Learn some English words

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which are very helpful for us to learn this lesson

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Because when you look for the signal in the drawing,

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if you don't know the English word,

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you may not know its meaning

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So now, let's get started

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PP_BATT_VCC refers to battery power supply

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In all iPhone models, BATT refers to battery power supply

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PP_VCC_MAIN refers to the main power supply

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This power supply name is used

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in the circuit diagram of iPhone 6 to 6s plus

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PP_VDD_MAIN is also the main power supply

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It is used in models such as iPhone 7 to iPhone 12 ProMax

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PP_VDD_BOOST refers to boost power supply

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It is used in iPhone 7 and above models

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The voltages required by other chips are

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converted by the main power supply

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Next, let's go to the circuit diagram to see these English signs

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We can see in the circuit diagram of the 6s plus model,

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This line identifies PP_BATT_VCC,

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which represents the battery power supply

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This line identifies PP_VCC_MAIN,

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which represents the main power supply

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Let's take a look at the circuit diagram of the iPhone x

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In this circuit, the line ID is also PP_BATT_VCC

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which represents the battery power supply

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In iPhone7 and above models, PP_VDD_MAIN

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represents the main power supply

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For example, in this iPhone x, VDD_MAIN

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represents the main power supply

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The power supply of PP_VDD_BOOST

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we mentioned earlier

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is only available for iPhone 7 and above models

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PP_VDD_BOOST is the boost power supply

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Its function is that when the battery power is too low,

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the boost chip will generate a power supply to provide

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working voltage to some important chips

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to prevent shutdown due to low battery voltage

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Well, these are the few English words

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we need to use to learn the standby circuit