
3. TECHNICAL BRIEF
- 61 -
LGE Internal Use Only
Copyright © 011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.14 KEY BACLKLIGHT LED Interface
Key Backlight LED is controlled by RT9396 (U301). If LED_PWM is high, Current is flowing from VBAT to LED.
Then Light emitted from The LED.
LED_PWM is operating PWM. It is reducing current consumption.
Figure 3-14-1 Key Backlight Block
1u
C319
1u
C320
1u
C321
8
V1
_
OI
_
M
A
C
R
W
P_
A
NL
_
MF
8
V1
_
E
R
O
C_
M
A
C
8
V2
_
A_
M
A
C
2.2u
C322
R309
15
LD300
LD301
C323
0.1u
VBAT
15
R310
C318
1u
1u
C315
VBAT
C312
1u
1u
C313
C314
1u
U301
24
23
22
21
20
19
18
8
7
6
5
9
4
10
3
11
2
12
1
31 41 51 61 71
L
C
S
A
D
S
N
E
M
W
P
F
C
D
N
G
P
LDO1
N2
C
LDO2
N1
C
LDO3
P1
C
LDO4
P2
C
AGND
VIN
LDOIN
LED6
LED5
LED4
LED3
LED2
LED1
VOUT
I2C_SDA
I2C_SCL
MLED1
MLED3
MLED2
MLED4
MLED5
LED_PWM
LCD_BL_CTRL