LG GS290 - Keypad Back-Light Illumination

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LGE Internal Use Only Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
GS290 Operational Description Revision B
LG Electronics 43/136 LGE Property
3.9. Keypad back-light illumination
There are 2 snow white color LEDs on Key FPCB for keypad illumination. Keypad Back-light is controlled by
SM-Power Flash LED port which has constant current control function. The whole configuration of the
SM-POWER Flash LED drivers is shown in below Figure11
.
Figure 11 Keypad Back-light LEDs
LD401LD404LD405
2
04
R
0
2
1
314R
0
2
1
224R
021
LD403
1
2
4R
021
604R
021
VBAT
LD400LD402
EVL5M02200
VA405
6
14
R
021
KEY_BL
KEY LED