TM
MP1529
Fixed Frequency Step-Up Converter
LCD Backlight Plus Flash
The Future of Analog IC Technology
TM
DESCRIPTION
The MP1529 is a step-up converter plus 3
current sources for driving two 6-LED backlight
strings to 30mA and a 4-LED flash string to
150mA from a single Lithium-Ion battery.
The step-up converter generates an output
voltage as high as 25V from a 2.7V to 5.5V
input source. Three current sources drive in
three modes. In backlight mode two strings of 6
LEDs are lit with up to 30mA of current. In the
backlight plus preview mode the 4 flash LEDs
are lit with the preview current. In flash mode
the flash LEDs are lit with up to 150mA of
current and the two backlight strings are turned
off. There are three pins to independently set
the backlight, preview and flash current.
The MP1529 includes built-in open lamp over
voltage protection, cycle-by-cycle current limit,
over temperature shutdown, input under voltage
control and integrated soft-start.
The MP1529 is available in a tiny 16-pin 4mm x 4mm
package.
FEATURES
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2.7V to 5.5V Input Voltage Range
25V Maximum Step-Up Voltage
<1µA Shutdown Mode
1.2MHz Fixed Frequency Operation
LCD Backlight to 30mA, Flash to 150mA
Cycle-By-Cycle Current Limit
Independent Backlight, Preview and Flash
Current Adjustment
Special PWM Dimming
Over Voltage Protection
Under Voltage Lockout
Integrated Soft-Start
Thermal Shutdown
Tiny 4mm x 4mm QFN Package
PDAs
Cellular Phones
Digital Still Cameras
Digital Video Cameras
APPLICATIONS
“MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic
Power Systems, Inc.
TYPICAL APPLICATION
V
IN
D1
16
IN
EN1
EN2
COMP
SW
OUT
14
12
V
OUT
Efficiency vs LED Current
(Backlight Mode, 2 Strings of 3 LEDs)
82
80
EFFICIENCY (%)
EN1
EN2
C4
10nF
1
2
3
4
9
10
11
6
V
IN
=4.2V
V
IN
=3.6V
V
IN
=2.7V
78
76
74
72
MP1529
SS
ISET1
ISET2
ISET3
GND
LED1
LED2
LED3
PGND
8
7
5
13, 15
2
4
GND
MP1529_TAC_S01
6 8 10 12 14 16 18 20
LED CURRENT (mA)
MP1529_EC01
MP1529 Rev. 1.0
11/23/2005
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2005 MPS. All Rights Reserved.
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MPS [ MONOLITHIC POWER SYSTEMS ]
