LG F1200 Service Manual page 29

3. TECHNICAL BRIEF
(9) Keypad back-light Illumination
There are 12 Deep Blue LEDs in Main Board for Keypad Backlight. Keypad Back-light is driven
by 'KEY_BACKLIGHT' (GPIO0) line from DBB.
KEY_BACKLIGHT
(10) LCD Back-light Illumination
MLED
LCD_BACKLIGHT
VBAT
6 5
Q301
IMX9T110
1 2
R360
1.5K
R359
100K
Figure 18. Keypad Back-light Scheme
VBAT
13
C404
C400 C499
1u
1u 1u
Figure 19. LCD Back-light driving scheme
- 28 -
4
3
R361
R358
20
20
U400 AAT3152IWP
8 3
IN C1+
C409
1u
5 4
OUTCP C1-
6
C2+
C401
2
EN_SET 1u
7
C2-
10
ISINK1
11
ISINK2
9 12
GND ISINK3
1
PGND ISINK4
R499 0
MLED1
MLED2
MLED3