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.

• 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 FEN 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)