Hello guys! How are you? Welcome once again to another of these lessons
we're reaching the end of the course, I hope you're learning a lot because after this
this is the Module 1 if we can call it like that, on this you should have learned concepts, measurements,
that you've practiced with boards
after this you have to learn about reballing, a GOOD reballing
we'll be talking about that
and then, we'll diagnose faults
and there's a much more, but
I'm trying my best so you can learn this bases
Please, leave a comment below, tell me what do you think about these lessons
what we should improve?
or make another videos
so you can learn better
Okay, so on the previous lesson
we saw this, how the board is powered
we saw this sketch where we said
the battery has 3.8 volts
it has a connector, passes through Tigris
reaches a regulator and this power the peripherals
So today we'll talk about the main lines
Main Lines
I identify these lines as "all those lines that will be present when I connect the battery"
once I connect the battery, those line will be generated WITHOUT the need to turn on the phone, this is very important
without turning on the phone, the main lines are generated
First, we'll see the iPhone 6
to iPhone 6S
the first lines that are generated are VCC_MAIN
this is a line of 3.8 volts
and we'll have a line called PP_BATT this is the battery line
the battery's voltage
and we'll have a line called 1.8V_ALWAYS
and this have a voltage of 1.8 volts
these are the main lines of iPhone 6 to 6S
Now, let's see how these lines are born
let's start, first let's say I have a battery
I'll use different colors to make it more understandable
my battery reaches a connector here
here it goes the positive voltage, and here the negative voltage
as I said on the previous lesson, this positive voltage
will power the circuit called Tigris
so, here, from here is the line called PP_BATT
PP_BATT ok?
this is the Tigris, and here's the MOSFET
and here reaches the battery
I don't want to explain too much about the MOSFET and Tigris
because that's something we'll see once we get on Charge
So, this is called PP_BATT
once I connect the battery these lines will be generated
Now, let's go to the ZXW
and touch the positive line of the battery
once I connect the battery, look, the voltage reaches this coil
this coil also power this circuit, it is a PA
we'll see it later
power this circuit
and look, it powers a lot of other circuits, all those circuits in blue
so that means, once I connected the battery, the line PP_BATT powered many circuits
let's make an example here, imagine the line PP_BATT
powered 7 ICs
now, when it passes through Tigris
this line passes and turns into VCC_MAIN
PP_BATT has a voltage of 3.8 volts, and VCC_MAIN also has a voltage of 3.8 volts
Now let's see VCC_MAIN on ZXW
here's my friend Tigris
when this passes to the other side, take a look on the name of this line
this is VCC_MAIN
now take a look how many components VCC_MAIN powers
it powers many components and many capacitors
all of those capacitors, all of them in red are being powered by VCC_MAIN
if we flip the board, the same, there are many components
that are powered by this line, there are MANY
so that means, once I connect the battery, PP_BATT is generated
from PP_BATT passes through Tigris, and from Tigris it turns into VCC_MAIN
we could say the battery line, PP_BATT with VCC_MAIN is exactly the same line, it just went through a circuit
and now it's called VCC_MAIN
let's say VCC_MAIN powers 70 components
then this line will go down, and it will power a regulator
later we'll see who's this
on one of the pads of this regulator, will generate a line that goes to CPU
that also goes to the power connector
to the connector of the power button
and this
will have 1.8 volts and it's called 1.8ALWAYS
If we go to the ZXW, we'll see on the power button
this line, this line is called "BUTTON_TO_AP_HOLD_KEY"
okay, this line over here
if we follow this line, we'll see on it's back side, it goes to a filter, and here is called
BUTTON_TO_AP_HOLD_KEY
and this comes from regulator
and also communicates with the CPU
this line is the one that'll help us to turn on the phone
so by now, we have 3 main lines
VCC_MAIN, PP_BATT and 1.8ALWAYS
there are 3 lines that must be present once the battery is connected
Let's see this, once I connected the battery
it will power many components
this is VCC_MAIN
and here's the other side
Now, we'll see how is this on iPhone 7 onwards
I'm talking about iPhone 7 to iPhone X, for example
I'll make a drawing here
once again we have a battery
now, this battery goes to the connector
from here, it goes to Tigris
and here's the mosfet
this is the same line, so it's called "PP_BATT"
Okay, PP_BATT, and here it comes out, who?
VCC_MAIN but it's called now VDD_MAIN, is exactly the same
this line will reach the regulator, but
remember, one pad of the regulator communicates with the power button and CPU
but this line, will go through another circuit called Boost
Boost is like the cousin of VCC_MAIN
at the time of the fight, the cousin comes to help, so VDD_BOOST
is a circuit that will help VDD_MAIN
when there's no battery, VDD_BOOST takes the lead and start to work
as a coil and other things, we'll see about that later, for now is not necessary
So, VDD_MAIN came and power it
VDD_MAIN, it came from here
and now, another line is generated, called VDD_BOOST
what does this mean? this means that on iPhone 7 onwards, we'll have
VDD_MAIN
is equal to 3.8 volts
VDD_BOOST is equal to 3.8 volts
PP_VBATT is equal to 3.8 volts
and 1.8ALWAYS
is equal to 1.8 volts
so these are the main lines
from iPhone 7 to iPhone XS Max
I haven't seen the schematic of the iPhone 11, but I daresay it might have them too
So, for now these are our main lines
just by connecting the battery, these main lines should be generated
for iPhone 6 or 6S, VCC_MAIN, PP_VBATT and 1.8ALWAYS
for iPhone 7 onwards, VDD_MAIN, VDD_BOOST
PP_VBATT and 1.8ALWAYS
these lines are present without the need of press the power button
just by connecting the battery, these lines are generated
later we'll be talking about the main consumptions, so you can understand them and we can talk about consumptions
That's everything for today's lesson guys, take care, I'll see you tomorrow for a new lesson
and let's keep learning
hugs everyone, bye!