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In this lesson, we talk about the description of the backlight screen circuit in the circuit diagram

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Let's take a look

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This is the drawing of an Android phone,

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the whole drawing of the backlit screen circuit

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Of course, in this drawing,

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we should first exclude a few points not to see

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The first one is this FP, the FP circuit is the fingerprint circuit,

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we don't consider it, because we're talking about display

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So the other one is TP,

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we don't consider the touch circuit that starts with TP

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We excluded these two categories, the red and blue ones

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Let's look at the power supply of the display circuit we are going to talk about

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The power supply of the display circuit is VOUT _1V8,

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which is its 1.8 volt power supply

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It also has the power supplies VSP and VSN

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We put the two of them together,

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usually called positive and negative voltage power supply,

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that is, screen power supply

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It's the power supply for the screen, not the backlight

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The general actual voltage of VSP and VSN is about 4.8 volts

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VSP is about 5 volts, and VSN is about -5 volts

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Then there is another power supply,

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that is, the backlight power supply, which is a high-voltage

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Let's take a look at the general rule of the backlight power supply

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A positive pole, we see that the LED minus 3 minus 1 and minus 2,

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minus is actually negative,

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which is the negative pole of the backlight,

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also called the loop, there are three loops

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A positive pole has 3 loops

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This is the backlight power supply

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What are we going to see after that?

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We're going to see the reset of the display,

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we see that there are RST, LCD

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LCD is the liquid crystal display, RST is the power supply reset

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There is also screen detection here,

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there are two lines, ID0 ID1

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There is also a TE, the sync signal, which is here

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J1701 is a display connector,

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it is actually a touch connector

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We're talking about the display at the moment,

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so we'll just look at the display circuit

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It also has a bus, also called a communication protocol,

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which starts with DSI and has four sets of data,

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data 0, data 1, data 2, and data 3

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Another is the clock signal

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It is not the clock signal of the screen, but the clock signal of the bus,

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which everyone should know

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Ok, this is a display of the backlight screen circuit in the circuit diagram

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Okay, that's it for this lesson