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3.11 LCD back-light illumination
Employed the BD6095 is a dual charge pump designed to support both the white LED backlight and
flash applications for systems operating with lithium-ion/polymer batteries. The backlight charge pump
is capable of driving up to five LEDs at a total of 65mA for backlight. The current sinks may be
operated individually or in parallel for driving higher current LEDs. To maximize power efficiency, the
charge pump operates in 1X, 1.33X, 1.5X, or 2X mode, where the mode of operation is automatically
selected by comparing the forward voltage of each LED with the input voltage.
Table 8 Charge pump IC LCD part current setting table
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3. TECHNICAL BRIEF
LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Figure 18 LCD Back light unit and Key backlight charge pump IC
1u
C105
E1
E6
VIO
B4
VOUT
WPWMIN
D1
B1
LED5
B2
A2
LEDFL
B3
LEDGND
RESETB
C4
SBIAS
F5
D5
SCL
D4
SDA
E5
SGND
SSENS
F3
T1
A1
A6
T2
T3
F6
F1
T4
F4
VBAT1
VBATCP
B5
VBATLDO
C1N
D6
C5
C1P
C6
C2N
C2P
B6
C3N
A4
C3P
A5
A3
CPGND
FLASHCNT
D3
GC1
E4
E3
GC2
LDO1O
F2
E2
LDO2O
D2
LED1
C2
LED2
LED3
C1
LED4
VIO_2V62
BD6095GUL
U101
VBAT
C108
10u
2.2u
C103
1u
C106
1u
C107
C104
1u
C110
1u
TP101
100K
R104
0.1u
C109
2V8_CAM 1V8_CAM
LCD_PWM
MLED1
MLED2
MLED3
MLED4
MLED
MLED5
BL_RESETB
I2C_SCL
I2C_SDA
FLASHCNT
SUB_KEY_BL
Summary of Contents for KC550
Page 1: ...Date May 2008 Issue 1 0 Service Manual Model KC550 Service Manual KC550 Internal Use Only ...
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