LT3592 500mA Wide Input Voltage Range Step-Down LED Driver with 10:1 Dimming FEATURES DESCRIPTION n Wide Input Voltage Range The LT 3592 is a 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 400kHz2.2MHz 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 LT3592s High V IN 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 LT3592 useful in a variety of applications. Current mode n Automotive Signal Lighting PWM architecture provides fast transient response and n Industrial Lighting cycle-by-cycle current limiting. Thermal shutdown provides n 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 APPLICATION 50/500mA Two Series Red LED Driver Ef ciency for 2 Red LEDs, L = 10H, 900kHz 100 V IN V BOOST IN 7V TO 32V 95 0.1F 1F LT3592 10H 90 SW BRIGHT 500mA 85 80 DA CAP 75 + SHDN ON 200/20mV 0.4 4.7F 70 BRIGHT OUT BRAKE 65 51k R T 60 V FB GND 55 140k 10k 900kHz 50 4 8 12 16 20 24 28 INPUT VOLTAGE (V) 3592 TA01a 3592 TA01b 3592fc 1 EFFICIENCY (%)LT3592 (Note 1) ABSOLUTE MAXIMUM RATINGS V , BRIGHT Voltages ................................ 0.3V to 36V SHDN Voltage ............................................................V IN IN BOOST Voltage .........................................................60V DA Pin Current (Average) ..................... 1.2A (sourcing) BOOST above SW pin ...............................................30V Operating Temperature Range (Notes 2, 3) CAP, OUT Voltages (OUT CAP) ...............................30V LT3592E ............................................. 40C to 125C V Voltage .................................................................4V LT3592I .............................................. 40C to 125C FB R Voltage ...................................................................6V Storage Temperature Range ................... 65C to 150C T PIN CONFIGURATION TOP VIEW TOP VIEW R 1 10 V T FB R 1 10 V T FB BRIGHT 2 9 OUT BRIGHT 2 9 OUT 11 11 SHDN 3 8 CAP SHDN 3 8 CAP V 4 7 BOOST IN V 4 7 BOOST IN DA 5 6 SW DA 5 6 SW MSE PACKAGE 10-LEAD PLASTIC MSOP DDB PACKAGE = 38C/W, = 8C/W JA JC 10-LEAD (3mm s 2mm) PLASTIC DFN EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB = 76C/W, = 13.5C/W JA JC EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3592EDDB PBF LT3592EDDB TRPBF LDCQ 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3592IDDB PBF LT3592IDDB TRPBF LDCQ 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3592EMSE PBF LT3592EMSE TRPBF LTDCR 10-Lead Plastic MSOP 40C to 125C LT3592IMSE PBF LT3592IMSE TRPBF LTDCR 10-Lead Plastic MSOP 40C to 125C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3592EDDB LT3592EDDB TR LDCQ 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3592IDDB LT3592IDDB TR LDCQ 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3592EMSE LT3592EMSE TR LTDCR 10-Lead Plastic MSOP 40C to 125C LT3592IMSE LT3592IMSE TR LTDCR 10-Lead Plastic MSOP 40C to 125C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. For more information on lead free part marking, go to: