DESCRIPTION
The LT® 3474/LT3474-1 are fi xed frequency step-down DC/DC converters designed to operate as constant-current sources. An internal sense resistor monitors the output current allowing accurate current regulation, ideal for driving high current LEDs. High output current accuracy is maintained over a wide current range, from 35mA to 1A, allowing a wide dimming range.

FEATURES
■ True Color PWM™ Delivers Constant Color with 400:1 Dimming Range
■ Wide Input Range: 4V to 36V
■ Up to 1A LED Current
■ Adjustable 200kHz–2MHz Switching Frequency
■ Adjustable Control of LED Current
■ Integrated Boost Diode
■ High Output Current Accuracy is Maintained Over a Wide Range from 35mA to 1A
■ Open LED (LT3474) and Short-Circuit Protection
■ High Side Sense Allows Grounded Cathode Connection
■ Uses Small Inductors and Ceramic Capacitors
■ LT3474-1 Drives LED Strings Up to 26V
■ Compact 16-Lead TSSOP Thermally Enhanced Surface Mount Package

APPLICATIONS
■ Automotive and Avionic Lighting
■ Architectural Detail Lighting
■ Display Backlighting
■ Constant Current Sources