LT3475-1 Datasheet | Linear Technology

.. LT3475/LT3475-1 Dual Step-Down 1.5A LED Driver Features - - DESCRIPTIO - - - - - - - - U APPLICATIO S - - - - True Color PWMTM Delivers Constant Color with 3000:1 Dimming Range Wide Input Range: 4V to 36V Operating, 40V Maximum Accurate and Adjustable Control of LED Current from 50m A to 1.5A High Side Current Sense Allows Grounded Cathode LED Operation Open LED (LT3475) and Short Circuit Protection LT3475-1 Drives LED Strings Up to 25V Accurate and Adjustable 200k Hz to 2MHz Switching Frequency Anti-Phase Switching Reduces Ripple Uses Small Inductors and Ceramic Capacitors Available in the pact 20-Lead TSSOP Thermally Enhanced Surface Mount Package The LT®3475/LT3475-1 are dual step-down DC/DC converters designed to operate as a constant-current source. An internal sense resistor monitors the output current allowing accurate current regulation ideal for driving high current LEDs. The high side current sense allows grounded cathode LED operation. High output current accuracy is maintained over a wide current range, from 50m A to 1.5A, allowing a wide dimming range. Unique PWM circuitry allows a dimming range of 3000:1, avoiding the color shift normally associated with LED current dimming. The high switching frequency offers several advantages, permitting the use of small inductors and ceramic capacitors. Small inductors bined with the 20 lead TSSOP surface mount package save space and cost versus alternative solutions. The constant switching frequency bined with low-impedance ceramic capacitors result in low, predictable output ripple. With its wide input range of 4V to 36V, the LT3475/LT3475-1 regulate a broad array of power sources. A current mode PWM architecture provides fast transient response and cycle-by-cycle current limiting. Frequency foldback and thermal shutdown provide additional protection. Automotive and Avionic Lighting Architectural Detail Lighting Display Backlighting Constant-Current Sources , LT, LTC and LTM...