4637 个问题 查看全部

# LCD Backlight pin out

I want to use the iPhone backlight panel as a readily available and cheap custom light source. With iPhone 4 backlights this was easy, as they only have 2 pins and when you apply 20V at 20mA they will light up beautifully.

But now I want to use the bigger iPhone 6 (or 6s) backlight with 3 pins. Can somebody please point me to a datasheet or give me information on these pins.

Thanks!

## 3个回答

To get the right answer posted:

it is 3 contacts (front and backside are connected with each other). 1+2 are GND and 3 is +18V. This will make all 12 LEDs light up.

One pin is + one is - and the other is a line for the U1502 backlight control ic chip.

Thanks a lot. Just to clarify: Does that mean you cannot get them to run that easily or will they light up fine even without having the IC connected? Also do you happen to know the pins for the 6 plus backlight - there are 5 pins on this one.

Ok well after testing it looks like you are wrong.

I tested it on an old iPhone 5S backlight (which has the same 3 pin cable) and there are actually 2 GNDs and one +12v powering 2 strands of 4 LEDs each. I guess this design is due to being able to dim the backlight even further by shutting down 4 of the 8 LEDs.

the iphone 6 & 6s backlights have dual voltage requirements. it has 6 pins.

With the light facing up and the connector down from left to right it would be :

pins 1 & 2 = ground

pin 3 = +18V

pin 4= +12v

pins 5 & 6 = ground

@lrod2344 Are you sure it is 6 pins and not just 3 accessible on both sides? I run it at +18V and it works fine. What is the supposed 12V pin good for?

When applying the same voltage to the 3rd and 4th contacts, only one of the two backlight sections is working. The backlighting works completely only if you apply two kinds of voltage +18 to 3 pin and +12 to 4 pin as mentioned in the post above. It is possible to put a resistor 300 ohms before the 4 pin, then both illumination sections will work equally. Most likely there is just such a resistor inside after 3 pin.

P.S. The possible reason for such a scheme is designed by Apple apparently so that people could think and develop in their spare time)

How do you know? When measuring the contact patches from the front and backside they have almost zero resistance and thus are directly connected. Also at 12V nothing lights up.

Actually it makes no sense:

There are 12 LEDs inside the backlight. Each needs ~3V to operate. With two separate grounds you have two circuits with 18V each. That is exactly 3V per LED at 12/2 LEDs. I can also make the LEDs light up left and right by connecting only one Ground at a time

Thank you for clarifying

Yesterday I did not pay attention to the phone model, I did backlight from the IPhone 6 plus

And Post by lrod2344 ITS about iphone 6 Plus.

Maybe my experience can be useful if you

How I connected:

-Connected 3-4 pins to + (from 14 volts dim to 18 very brightly)

- 1-2 (ground for +18) connected to the ground

- 5-6 (ground for +12) soldered resistor of 300 Ohm and connected to ground

At 15 volts, a very comfortable illumination for the screen of Elliptical trainer.

P.S. When I was looking for the backlight schematic yesterday. I got a picture with problems with backlighting on IPhone 6 plus I thought there were 11 LEDs on photo

Probably in two lines a different number for example in one of their 6 pieces in another 5 diodes.

mailand 将永远感激不已