3. TECHNICAL BRIEF
- 47 -
LGE Internal Use Only
Copyright © 011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
The RT9396 is a power management IC (PMIC) for backlighting and phone camera applications.
The PMIC contains a 6-Channel charge pump white LED driver and four low dropout linear regulators.
The charge pump drives up to 6 white LEDs with regulated constant current for uniform intensity.
Each channel (LED1 to LED6) supports up to 25mA of current. These 6-Channels can be also programmed as
4 plus 2-Channels or 5 plus 1-Channels with different current setting for auxiliary LED application.
The RT9396 maintains highest efficiency by utilizing a x1/ x1.5/ x2 fractional charge pump and low dropout
current regulators. An internal 6-bit DAC is used for backlight brightness control. Users can easily configure
up to 64-steps of LED current via the I2C interface control. The RT9396 also comprises low noise, low dropout
regulators, which provide up to 200mA of current for each of the four channels. The four LDOs deliver 3%
output accuracy and low dropout voltage of 200mV @ 200mA.
Users can easily configure LDO output voltage via the I2C interface control. The LDOs also provide current
limiting and over-temperature functions. The RT9396 is available in a WQFN-24L 3x3 package.
Figure 3-9-2. RT9396 CIRCUIT DIAGRAM
VCAM_IO_1V8
R606
100K
DNI
R603
R604
0
VBAT
C602
1u
1u
C601
C610
1u
1u
C609
C608
1u
FM_LNA_EN
VCAM_DIG_1V8
VCAM_ANA_2V8
2.2u
C605
2.2u
C611
C604
1u
RT9396
U601
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
LCD_LED_CA5
LCD_LED_CA4
LCD_LED_CA3
LCD_LED_CA2
LCD_LED_CA1
LCD_PWM
I2C_SDA
I2C_SCL
FM_LNA_EN
LCD_BL_CTRL