3. TECHNICAL BRIEF
- 43 -
Copyright © 2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
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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 3.9.2 Charge Pump CIRCUIT DIAGRAM
3. TECHNICAL BRIEF
44
Figure 3.9.2 Charge Pump CIRCUIT DIAGRAM
1u
C353
C355
1u
C356
2.2u
C35
1
2.2
u
1
2
VMMC_3V
3
VIO_1V
8
R351
1K
1u
C354
1
2
C357
2.2u
1
2
VBAT
U302
21
20
19
18
8
7
6
5
9
4
10
3
11
2
12
1
13
14
15
16
17
LED3
LED4
NC2
LDO
2
AVIN
C1
N
LDO
1
C2
N
AGND
PGND
NC1
C2
P
ENA
C1
P
PVIN
SCL
SDA
LED2
LED1
VOUT
SLUG_G
C352
33p
VBAT
VFM_2V
8
C360
2.2u
I2C_SDA2
I2C_SCL2
LCD_LED_CA1
LCD_LED_CA2
LCD_LED_CA3
LCD Charge Pump
(10V)
Changed (8/8)
Changed (10/30)
NP0 --> X7R (8/27)
Added for NC pin (8/21)