LT3592 500mA Wide Input Voltage Range Step-Down LED Driver with 10:1 Dimming FEATURESDESCRIPTION n Wide Input Voltage Range The LT®3592 is a fi xed frequency step-down DC/DC con- Operation from 3.6V to 36V verter designed to operate as a constant-current source. n Resistor Adjustable 400kHz–2.2MHz Switching An external sense resistor monitors the output current Frequency allowing accurate current regulation, ideal for driving n Shorted and Open LED Protected high current LEDs. The output current can be dimmed n Internal Switch Current Sense Resistor by a factor of 10 using an external signal for nighttime n External Resistor Programs LED Current, Pin brake lights. Selects 10:1 Ratio The high switching frequency offers several advantages by n 50mA/500mA LED Current Settings permitting the use of a small inductor and small ceramic n Catch Diode Current Sense to Prevent Runaway at capacitors. Small components combined with the LT3592’s High VIN 10-pin DFN leadless surface mount package save space and n Small Thermally Enhanced 10-Lead DFN cost versus alternative solutions. The constant switching (2mm × 3mm) and MSOP-10 Packages frequency combined with low-impedance ceramic capaci- tors result in low, predictable output ripple. APPLICATIONS A wide input voltage range of 3.6V to 36V makes the n LT3592 useful in a variety of applications. Current mode Automotive Signal Lighting n PWM architecture provides fast transient response and Industrial Lighting n cycle-by-cycle current limiting. Thermal shutdown provides Constant-Current, Constant Voltage Supplies additional protection. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION50/500mA Two Series Red LED DriverEffi ciency for 2 Red LEDs, L = 10μH, 900kHz 100 VIN VIN BOOST 7V TO 32V 95 1μF LT3592 0.1μF 10μH 90 SW BRIGHT 500mA 85 DA 80 CAP 75 SHDN + ON 200/20mV 0.4Ω 4.7μF 70 – BRAKE BRIGHT OUT EFFICIENCY (%) 65 51k RT 60 VFB GND 140k 55 10k 900kHz 50 4 8 12 16 20 24 28 3592 TA01a INPUT VOLTAGE (V) 3592 TA01b 3592fc 1