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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. TECHNICAL BRIEF
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The RT9367C is an integrated solution for backlighting and phone camera input supply. The part contains
a charge pump white LED driver and dual low dropout linear regulators. This IC can be shut down by
pulling EN low.
In the section of charge pump, The RT9367C can power up 4 white LEDs with regulated constant current
for uniform intensity. Each channel (LED1-LED4) can support up to 25mA. The part maintains highest
efficiency by utilizing a x1/x1.5/x2 fractional charge pump and low dropout current regulators. An internal
5-bit DAC is used for brightness control. Users can easily configure up to 32-step of LED current by I2C
interface.
In the section of linear regulator, The RT9367C comprises a dual channel, low noise, and low dropout
regulator sourcing up to 300mA at each channel. The range of output voltage can be configured from
1.1V to 3.3V by I2C interface. The outputs of LDO offer 3% accuracy and low dropout voltage of 250mV @
300mA. The LDO also provides current limiting and output short circuit thermal folded back protection.
Figure 3.10.2 Charge Pump CIRCUIT DIAGRAM
3. TECHNICAL BRIEF
2.2u
C410
VIO VBAT
1u
C411
1u
C412
2.2u
C413
100K
R417
VHP
1u
C414
33p
C415
33p
C416
33p
C417
33p
C418
1u
C457
VBAT
U400
12
20
19
18
8
7
6
5
9
4
10
3
11
2
21
1
13
41
15
16
17
LED3
LED4
NC2
2
O
DL
AVIN
N1
C
1
O
DL
N2
C
D
N
G
A
D
N
G
P
NC1
P2
C
ENA
P1
C
PVIN
SCL
SDA
LED2
LED1
VOUT
G_
G
UL
S
LED_CA1
LED_CA2
LED_CA3
I2C_SDA2
I2C_SCL2
Charge Pump