Keypad Light - LG CU500 Service Manual

3. TECHNICAL BRIEF
3.11.6 Folder ON/OFF Operation
There is a magnet to detect the Folder status, opened or closed.
If a magnet is close to the hall-effect switch, the voltage at pin1 of U504 goes to 0V. Otherwise, 2.6V.
This folder signal is delivered to MSM6275 GPIO43.
FOLDER_DETECT

3.11.7 Keypad Light

There are 16 White LEDs in Main board backlight circuit, which are driven by KYBD_BACKLIGHT line
from PM6650.
+VPWR
(For Hall Sensor)
C489
0.01u
Figure. Schematic of Folder ON/OFF detection circuit
KEY_BACK_LIGHT
R465
100
R466
100
R467 R468
100 100
R469 R495
100 100
R471 R472
100 100
Figure. Keypad Backlight Circuit
R504
100K
U504 A3212EEH-T
1 6
OUTPUT VDD
2 5
NC1 NC2
4
GND2
3 7
GND1 PGND
R451
100
R456
100
R458
100
R1044
100
- 56 -
VREG_MSMP_2.7V
R402
62
R452
100
R1045
100
R457
100
R459
100
KYBD_BACKLIGHT