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.