MP1529

Fixed Frequency Step-Up Converter

LCD Backlight Plus Flash

MP1529 Rev. 1.0

www.MonolithicPower.com

1

11/23/2005

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2005 MPS. All Rights Reserved.

The Future of Analog IC Technology

TM

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

• 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

APPLICATIONS

• PDAs

• Cellular Phones

• Digital Still Cameras

• Digital Video Cameras

“MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic

Power Systems, Inc.

TYPICAL APPLICATION

MP1529_TAC_S01

MP1529

IN

SW

OUT

COMP

SS

ISET1

ISET2

ISET3

GND

LED1

LED2

LED3

PGND

14

12

8

7

5

13, 15

EN1

EN2

16

3

4

9

10

11

6

1

2

D1

EN1

EN2

C4

10nF

GND

82

80

78

76

74

72

2 4 6 8 10 12 14 16 18 20

LED CURRENT (mA)

MP1529_EC01

Efficiency vs LED Current

(Backlight Mode, 2 Strings of 3 LEDs)