DESCRIPTION
The LT®3478/LT3478-1 are 4.5A step-up DC/DC converters designed to drive LEDs with a constant current over a wide programmable range. Series connection of the LEDs provides identical LED currents for uniform brightness without the need for ballast resistors and expensive factory calibration.

FEATURES
■ True Color PWM™ Dimming Delivers Constant LED
   Color with Up to 3000:1 Range
■ Wide Input Voltage Range: 2.8V to 36V
■ 4.5A, 60mΩ, 42V Internal Switch
■ Drives LEDs in Boost, Buck-Boost or Buck Modes
■ Integrated Resistors for Inductor and LED Current
   Sensing
■ Program LED Current:
   100mA to 1050mA (LT3478-1)
   (10mV to 105mV)/RSENSE (LT3478)
■ Program LED Current De-Rating vs Temperature
■ Separate Inductor Supply Input
■ Inrush Current Protection
■ Programmable Soft-Start
■ Fixed Frequency Operation from 200kHz to 2.25MHz
■ Open LED Protection (Programmable OVP)
■ Accurate Shutdown/UVLO Threshold with
   Programmable Hysteresis
■ 16-Pin Thermally Enhanced TSSOP Package

APPLICATIONS
■ High Power LED Driver
■ Automotive Lighting