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In this lesson, we will talk about the power chips

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The power chip is referred to as PMU,

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and its full name is called the power management unit,

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so it is referred to as PMU, or PMIC

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What is the role of the power supply?

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It is responsible for converting the Vage of about 4V provided by the battery

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into the main power supply of the circuits,

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or into BUCK circuits,

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or the Vage of the linear regulator,

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provide the power supply to the CPU,

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the temporary storage font, the radio frequency circuit,

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the camera circuit, WiFi circuit, etc.

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Simply put, the power chip is a power conversion chip

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It converts the power of the battery into a switching power supply,

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and converts it into the high and low Vages required by different chips

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through the internal BUCK and LDO modules

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The frame on the left shows the two power chips of the mainboard

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What is the main power supply in the circuit?

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From the name, it is known that it is a main power supply,

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which will be supplied to the power supply,

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with a Vage of 3.8-4.3 V

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OK let's take a look

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Input a high Vage,

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after step-down conversion, output a low Vage,

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the output Vage is less than the input Vage,

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this is called step-down

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For example, in the circuit,

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we input a Vage of 3.8-4.3 V to the power chip

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After it meets the conditions, we press the power button signal,

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that is, connect the power button signal to the ground wire,

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which will pull down the 1.8V,

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and we pull it down for more than 5 seconds

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Generally at this time,

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the power chip will output a lot of relatively low Vages,

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for example,

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it will generate 0.6-1.8V

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You see, its input is 3.8-4.3V,

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and the output Vage is obviously very low, 0.6V to 1.8V,

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this is step-down

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It will also generate a 1.2-1.8 V power supply to the running memory,

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and a 1.8-3 V power supply to the font library

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Other functions

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such as the time circuit

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For example, clock signal generates time circuit

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We can see the time in the mobile phone,

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that is the time circuit is working

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The temperature detection circuit is also on the power chip

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Temperature detection is to detect the temperature of the main functional modules

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in different positions on the mainboard

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When the temperature is too high,

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the mobile phone will issue a warning that the temperature is too high to protect the mobile phone

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The power chip also has the functions of overvoltage protection and overcurrent protection

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Overvoltage protection means that when the voltage is too high and does not meet the standard,

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it will protect the circuit

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Overcurrent protection means that when a failure occurs in the circuit and a large current is generated,

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it will stop the circuit and play a protective role

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The above is the role of the power chip

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In actual maintenance,

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the main function of the power supply chip is to reduce the voltage

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After the input power supply is reduced by multiple modules inside the power supply,

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it is supplied to the CPU, temporary storage,

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font library, etc.

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Alright, that's it for this lesson