Key Baclklight Led Interface - LG LG500G Service Manual

3. TECHNICAL BRIEF

3.14 KEY BACLKLIGHT LED Interface

Key Backlight LED is controlled by switch (Q200). If KEY_BL_EN is high, Current is flowing from VBAT to LED.
Then Light emitted from The LED.
KEY_BL_EN is operating PWM. It is reducing current consumption.
VBAT
VBAT
R301 R302
270 270
Q300
LGE Internal Use Only
R303 R304 R305 R306 R307
270 270 270 270 270
3
R326
2
1K
1
C337
R327
100K
1u
Figure 3-14-1 Key Backlight Block
R308 R309 R310 R311
270 270 270 270
KEY_BL_EN
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3. TECHNICAL BRIEF
R312 R349 R350
270 270 270
Only for training and service purposes