MP2481

36V, 1.2A, 1.4MHz

White LED Driver

MP2481 Rev. 1.42

www.MonolithicPower.com

1

4/28/2012

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

© 2012 MPS. All Rights Reserved.

The Future of Analog IC Technology

DESCRIPTION

The MP2481 is a 36V, 1.2A, white LED driver

suitable for either step-down or inverting

step-up/down applications. It achieves 1.2A

peak output current over a wide input supply

range with excellent load and line regulation.

Current mode operation provides fast transient

response and eases loop stabilization. Fault

condition protection includes thermal shutdown,

cycle-by-cycle peak current limiting, input over

voltage protection, open strings protection and

output short circuit protection.

The MP2481 incorporates both DC and PWM

dimming onto a single control pin. The separate

input reference ground pin allows for direct

enable and/or dimming control for a positive to

negative power conversion.

The MP2481 requires a minimum number of

readily available standard external components

and is available in 8-pin MSOP8E package.

EVALUATION BOARD REFERENCE

Board Number

Mode

EV2481-H-00A

Step-down

EV2481-H-01A

Step-up/down

FEATURES

• 1.2A Maximum Output Current

• Unique Step-up/down Operation (Buck-

Boost Mode)

• Wide 4.5V to 36V Operating Input Range for

Step-Down Applications (Buck Mode)

• 0.30Ω Internal Power MOSFET Switch

• Fixed 1.4MHz Frequency

• Analog and PWM Dimming

• 0.2V Reference Voltage

• Up to 95% Efficiency

• 5μA Shutdown Mode

• No minimum LED required

• Stable with Low ESR Output Ceramic

Capacitors

• Cycle-by-Cycle Over Current Protection

• Thermal Shutdown Protection

• Open Strings Protection

• Input Over Voltage Protection

• Output Short Circuit Protection

• Available in 8-Pin MSOP8E Package

APPLICATIONS

• General LED Illuminations

• LCD Backlight Panels

• Handheld Computers

• Automotive Internal Lighting

• Portable Multimedia Players

• Portable GPS Devices

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 Trademarks of Monolithic Power

Systems, Inc.

TYPICAL APPLICATION (STEP-UP/DOWN APPLICATION)

MP2481

SW

FB

BST

VSS

VDD

OVP

EN/DIM

INGND

Cbs

1

5

6

2

4

8

7

3

D1

3 series, 9 paralleled

C1

VIN

4.5V-36V

L1

C2

R1

R2

Rs

OFF

DC or PWM INPUT

ON

Efficiency vs. Input

Step-up/down Application

Voltage

60

65

0

5

10

15

20

25

30

70

75

80

85

90

INPUT VOLTAGE (V)

4 series,400mA

3 series,400mA

3 series,9 paralleded,180mA total