MAX1553/MAX1554

High-Efficiency, 40V Step-Up

Converters for 2 to 10 White LEDs

EVALUATION KIT AVAILABLE

General Description

The MAX1553/MAX1554 drive white LEDs in series with

a constant current to provide efficient display backlight-

ing in cellular phones, PDAs, and other hand-held

devices. The step-up converter includes an internal

efficiency and maximum battery life. The MAX1553 has

a current limit of 480mA for driving two to six white

LEDs, while the MAX1554 has a current limit of 970mA

for driving up to 10 white LEDs.

A single analog/PWM Dual Mode

™ input provides two

simple means of brightness adjustment. A separate

enable input provides on/off control. Soft-start mini-

mizes inrush current during startup.

The MAX1553/MAX1554 are available in space-saving

8-pin TDFN 3mm x 3mm packages.

Applications

Cellular Phones

PDA, Palmtop, and Wireless Handhelds

Color Display Backlight

Benefits and Features

Range of Backlighting Applications

•

Constant-Current Regulation for Even LED

Illumination

•

Internal 40V MOSFET Switch Capable of Driving

10 LEDs

•

2.7V to 5.5V Input Voltage Range

•

Analog or PWM Control of LED Intensity

•

Optimized for Low Input Ripple

•

Up to 88% Efficiency Driving 6 LEDs

•

Up to 82% Efficiency Driving 9 LEDs (20mA,

•

Small, Low-Profile External Components

TOP VIEW

SS

BRT

6

7

8

0V

LX

3

2

1

EN

GND

5

FB

4

TDFN

3mm x 3mm

MAX1553

MAX1554

Pin Configuration

Ordering Information

LX

SS

FB

ON

OFF

BRT

GND

2.7V TO 5.5V

INPUT

OV

EN

PWM

OR

DC CONTROL

MAX1553

MAX1554

WHITE

LEDS

Typical Operating Circuit

PART

TEMP RANGE

PIN-PACKAGE

TOP

MARK

MAX1553ETA

-40°C to +85°C 8 TDFN 3mm x 3mm

AGX

MAX1554ETA

-40°C to +85°C 8 TDFN 3mm x 3mm

AGY

Dual Mode is a trademark of Maxim Integrated Products, Inc.

19-2875; Rev 2; 5/15