DESCRIPTION
The LTC®3218 is a low-noise, high-current charge pump DC/DC converter capable of driving high current LEDs at up to 400mA from a 2.9V to 4.5V input. A low external parts count (one flying capacitor, two programming resistors and two bypass capacitors at VIN and CPO) make the LTC3218 ideally suited for small, battery-powered applications.

FEATURES
■ Low Noise Constant-Frequency Operation
■ Multi-Mode Operation: 1x or 2x Boost Mode
■ Automatic Mode Switching
■ High Output Current: 150mA (Continuous), 400mA
   (Pulsed) From Li-Ion/Polymer Input
■ 2-Second Flash Current Timeout for LED Protection
■ Automatic Soft-Start
■ Output Disconnect
■ No Inductors
■ 220mΩ Internal High Side Current Sense Resistor
■ Single Resistor Programming Capability
■ Tiny Application Circuit (3mm × 2mm DFN Package,
   All Components < 1mm High)

APPLICATIONS
■ LED Torch/Flash Supply for DSCs/Cellphones