TM
MP1519 – 1X, 1.5X, 2X CHARGE PUMP 4 WHITE LED DRIVER
OPERATION
The MP1519 is a charge pump that drives 4
LEDs from a 2.5V to 5.5V input voltage. It
automatically switches between 1x, 1.5x and 2x
charge pump modes to optimize efficiency while
maintaining LED current regulation.
The MP1519 employs soft switching and
soft-start to prevent overloading the battery
source at turn-on and charge pump mode
switching.
While operating, the MP1519 continually
monitors the LED current and battery voltage
and automatically switches between charge
pump modes to retain LED current regulation
through all LEDs as the battery voltage
fluctuates.
Four drivers independently regulate the current
through the LEDs, therefore matching LEDs are
not required.
FAULT
LED1
14
CURRENT
SOURCE
BATT
5, 13
BATTERY
SENSOR
BATT
FAULT
FAULT
FAULT
LED2
15
CURRENT
SOURCE
EN
12
ENABLE
CONTROLLER
LED3
16
CURRENT
SOURCE
SHUTDOWN
LED4
1
CURRENT
SOURCE
LED
ENABLE
ISET
RADJ
11
CURRENT
GENERATOR
LED4
LED3
LED2
LED1
PUMP SOFT
MODE START
LEDC
8
C1A
4
1.25V
BANDGAP
REFERENCE
C1B
7
CHARGE PUMP
C2A
6
GND
3, 10
C2B
9
Figure 1—Functional Block Diagram
MP1519 Rev. 1.9
7/27/2006
www.MonolithicPower.com
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© 2006 MPS. All Rights Reserved.
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