3. TECHNICAL BRIEF
3.12 LCD back light illumination
MAX8630W is a charge pump designed to support PWM control mode. And MAX8630W supports 5 white LEDs. The MAX8630W is capable of driving up to 5 LEDs at a total of 100mA(MAX8630W 100mA).
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, 1.5X, or 2X mode, where the mode of operation is automatically selected by comparing the forward voltage of each LED with the input voltage.
LCD BACKLIGHT
DBB_BL_PWM
LCD_BL_PWM
VBAT
C104
1u
R114 DNI
R115 0
R116 | 100K |
C103 1u
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| 6 | 2 |
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3 | IN | C1P | C1N |
| OUT | 7 | |||
1 | GND |
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| LED1 | 14 | |||
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| 13 | ||
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| U100 |
| LED2 | |
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| LED3 | 12 | |
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| MAX8630W | 11 | |||
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| LED4 | |
| 9 | CPWM |
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| LED5 | 10 | ||
| 8 | PWM | C2P | C2N | P_GND | 15 | |||
| C114 |
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| 5 | 4 |
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| 0.1u |
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C113
1u
9p | 9p | 9p | 9p | 9p | 9p |
C107 | C108 | C109 | C110 | C111 | C112 |
MLED
MLED1
MLED2
MLED3
MLED4
MLED5
C115 1u
Figure 13. Charge-Pump Circuit
LGE Internal Use Only | - 44 - | Copyright © 2008 LG Electronics. Inc. All right reserved. |
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| Only for training and service purposes |
