FEATURES

2? Accurate and Programmable LED Current up

to 1.2A in 128 Steps

? Total Solution Size < 30mm2

? 90% Peak Efficiency

? Drives 2 LEDs in Series with 1.2A from 5V

Input

? Drives 2 LEDs in Series with 600mA from 3.0V

Input

? Drives 1 LED with 1.2A from 3.0V Input

? Adjustable Over-Voltage Protection Allows for

Single or Series LED Operation

? Four Operating Modes: Torch, Flash, Indicator,

and Voltage Mode (4.98V)

? Programmable Flash Pulse Safety Timer in 16

Steps

? TX Input Ensures Synchronization with RF

Power Amplifier Pulse or Prevents LED from

Overheating

? LED Disconnect During Shutdown

? Flash/Imager Synchronization via F EN Pin

? Active Low Hardware Reset

? Multi-Function Pin (RESET and GPIO)

? Low Profile 12-pin WSON Package

(DQB0012A: 3mm x 3mm x 0.8mm, 0.4mm

pitch)

APPLICATIONS

? Camera Phone LED Flash

? Smartphone and PDA Flash

? LED Backlight

DESCRIPTION

The LM3553 is a fixed frequency, current mode step- up DC/DC converter with two regulated current sinks.

The device is capable of driving loads up to 1.2A

from a single-cell Li-Ion battery.

The LM3553 includes a TX pin that forces Torch

mode during a flash event allowing for

synchronization between the RF power amplifier and

Flash/Torch modes. It also includes a multi-function

pin (M/F) that can serve as a GPIO and a hardware

RESET pin.

The LM3553 is available in a 3mm by 3mm package.