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1.2A Dual Flash LED Driver System with I2C Compatible Interface

Inventory: In stock


Limit:  1

Features for the LM3553SDEV

  • 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 LLP Package (SDF12A: 3mm x 3mm x 0.8mm, 0.4mm pitch)


  • Camera Phone LED Flash
  • Smartphone and PDA Flash
  • LED Backlight


Description for the LM3553SDEV

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.

One or more high current flash LEDs can be driven in series either in a high power Flash mode or a lower power Torch mode controlled by either an internal register or the FEN pin. Additionally a low current (20mA) indicator mode and a fixed output voltage mode are also available.

The LM3553 has 128 current levels and 176 flash safety timer durations that are user adjustable via an I2 C compatible interface. Internal soft-start eliminates large inrush currents at start-up. Over-voltage protection circuitry and 1.2MHz switching frequency allow for the use of small, low-cost output capacitors with lower voltage ratings.

The LM3553 is an asynchronous step-up DC/DC converter with an I2C compatible control interface designed for white LED Flash applications. The evaluation board is setup to drive two white flash LEDs with a series flash current of 500mA. Flash duration and current can both be configured by adjusting values stored in the internal control registers. The LM3553 is available in a 3 mm by 3mm LLP package.