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Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. TECHNICAL BRIEF
3.10. Keypad back-light illumination
There are two kind of white LEDs on the Key FPCB and Key PCB for keypad illumination. Keypad
Back-light is controlled by GPIO port of the S-GOLDRADIO(KEY_BL) and by Backlight charge pump
IC(BD6095).
Figure 16 Slide Key PCB Back-light LEDs
Figure 17 Key FPCB Back-light LEDs
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.
VBAT
1u
C711
R711
47
1u
C710
R716
10
R717
10
R715
12K
R714 12K
LD701
LD700
R709
0
47
R712
R713
DNI
Q700
KTC4075E
2
3
1
DNI
R710
MLED
SUB_KEY_BL
UPPER_KEY_BL
KEY BACKLIGHT
LEWWS44-E
LD601
10
R609
LD600
LEWWS44-E
VBAT
R610
10
KEY_BL