DESCRIPTION
The LT®3954 is a DC/DC converter designed to operate as a constant-current source and constant-voltage regulator. It features an internal low side N-channel MOSFET rated for 40V/5A. The LT3954 is ideally suited for driving high current LEDs, but also has features to make it suitable for charging batteries and super capacitors. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages.

FEATURES
■ 3000:1 True Color PWM™ Dimming for LEDs
■ Wide VIN Range: 4.5V to 40V
■ Rail-to-Rail Current Sense Range: 0V to 40V
■ Internal 40V/5A Switch
■ Programmable PWM Dimming Signal Generator
■ Constant Current (±3%) and Constant-Voltage (±2%) Regulation
■ Accurate Analog Dimming
■ Drives LEDs in Boost, SEPIC, CUK, Buck Mode, Buck-Boost Mode, or Flyback Configuration
■ Output Short-Circuit Protected Boost
■ Open LED Protection and Reporting
■ Adjustable Switching Frequency: 100kHz to 1MHz
■ Programmable VIN UVLO with Hysteresis
■ C/10 Indication for Battery Chargers
■ Low Shutdown Current: <1µA
■ Thermally Enhanced 5mm × 6mm QFN Package

APPLICATIONS
■ High Power LEDs
■ Output Short-Circuit Protected Boost
■ Battery and SuperCap Chargers
■ Accurate Current Limited Voltage Regulators