MP3389

12–String, Step-up

White LED Driver

MP3389 Rev. 1.04

www.MonolithicPower.com

1

3/27/2013

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2013 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP3389 is a step-up controller with 12-

channel current sources designed for driving

the WLED arrays for large size LCD panel

backlighting applications.

The MP3389 uses current mode, fixed frequency

architecture.

The

switching

frequency

is

programmable by an external frequency setting

resistor. It drives an external MOSFET to boost

up the output voltage from a 5V to 28V input

supply. The MP3389 regulates the current in

each LED string to the programmed value set by

an external current setting resistor.

The MP3389 applies 12 internal current

sources for current balance. And the current

matching can achieve 2.5% regulation accuracy

between strings. Its low 550mV regulation

voltage on LED current sources reduces power

loss and improves efficiency.

PWM dimming is implemented with external

PWM input signal or DC input signal. The

dimming PWM signal can be generated internally,

and the dimming frequency is programmed by

an external setting capacitor.

FEATURES

• High Efficiency and Small Size

• 5V to 28V Input Voltage Range

• Balanced Driver for 12 Strings of WLEDs

• Maximum 60mA for Each String

• 2.5% Current Matching Accuracy Between

Strings

• Programmable Switching Frequency

• PWM or DC Input Burst PWM Dimming

• Open and Short LED protection

• Programmable Over-voltage Protection

• Under Voltage Lockout

• Thermal Shutdown

• 28-pin TSSOP and 28-pin SOIC Package

APPLICATIONS

• Desktop LCD Flat Panel Displays

• Flat Panel Video Displays

• LCD TVs and Monitors

All MPS parts are lead-free and adhere to the RoHS directive. For MPS green

status, please visit MPS website under Quality Assurance. “MPS” and “The

Future of Analog IC Technology” are Registered Trademarks of Monolithic

Power Systems, Inc.

TYPICAL APPLICATION

VIN

5V~28V

MP3389

ISENSE

GATE

EN

OSC

NC

BOSC

GND

DBRT

NC

OVP

LED1

LED2

LED3

8

1

10

7

6

9

26

24

28

23

22

21

Enable

DIMMING

L1

D1

R1

R2

M2

LED4

LED5

LED6

20

19

18

17

VIN

VCC

COMP

2

3

4

5

ISET

VCC

LED12

LED11

LED10

11

12

13

14

LED9

VFAULT

27

PGND

25

LED7

LED8

16

15

M1