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Hello everyone, today we continue to analyze the pin definitions of several other power supply

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chips on the Wistron 15221 motherboard.

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Mainly introduce the pin definitions of U4002, U4001, U4004 and PU5304 chips

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Let's take a look at U4001 and U4002 first

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Both U4001 and U4002 are switching power supply chips

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Take the APE8910 U4001 as an example

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Its pin 4 is the power supply pin, which is the working voltage of this chip, which comes from 5V_S5

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Its VIN1 and VIN2 are two voltage input pins

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ON1 and ON2 are two open signals

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VOUT1 and VOUT2 are two output pins

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When the chip is powered and turned on, it will convert VIN1 and output it from VOUT1

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This is also what we often call the secondary power supply

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It will also turn VIN2 out and output from VOUT2

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Usually ON1 turns on VIN1 to output from VOUT1,

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ON2 turns on VIN2 to output from VOUT2

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Ok, this is the pin definition of the U4001 switch power supply chip

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Their output voltage has no voltage drop, directly converts 5V_S5 standby into 5V_S0,

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and converts 3D3V_S5 standby into 3D3V_S0

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This is called two-stage voltage conversion, level conversion, no voltage drop

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Next, let's look at U4004

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U4004 is an LDO power supply chip

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VIN is the power supply input pin

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VOUT is the power supply output pin

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VBIAS is the chip operating voltage

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EN is an open signal, active high

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When the chip is powered by VBIAS, it also gets the VIN and EN open signals

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It will VIN voltage after the internal step-down

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Output voltage from VOUT pin

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In this circuit, it converts 1D0V_S5 into 0D95V_VCCIO output through internal step-down

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Supply power to the VCCIO pin of the CPU

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This is the pin definition of chip U4004