LT3590 48V Buck Mode LED Driver in SC70 and 2mm x 2mm DFN FEATURES DESCRIPTION 4.5V to 55V Input Voltage Range The LT 3590 is a xed frequency buck mode converter Up to 50mA LED Current speci cally designed to drive up to 10 LEDs in series from 80mA, 55V Switch a 48V DC source. Series connection of the LEDs provides Internal Schottky Diode identical LED currents of up to 50mA, resulting in uniform 15A Supply Current in Shutdown brightness and eliminating the need for ballast resistors. 500A Supply Current Operating, Not Switching A xed frequency, current mode architecture results in Switching Frequency: 850kHz stable operation over a wide range of input voltage and 200mV Feedback Voltage with 5% Accuracy output voltage. CTRL Input Performs Dimming and Shutdown The high switching frequency of 850kHz permits the use 91% Ef ciency (10 LEDs, 50mA) of tiny, low pro le inductors and capacitors. A single pin Requires Only 1F Output Capacitor performs both shutdown and accurate LED dimming 8-Lead SC70 Package control. The power switch, Schottky diode and control 6-Lead 2mm 2mm DFN Package circuitry are all contained inside a space saving SC70 package or 2mm 2mm DFN package to allow a small converter footprint and lower parts cost. APPLICATIONS , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. LED Fixed Signage All other trademarks are the property of their respective owners. Traf c Signs Neon Sign Replacement TYPICAL APPLICATION Buck Mode Driver for Ten White LEDs Conversion Ef ciency 100 1F 90 50mA 4 80 V IN 48V 1F 70 V IN LED 470H CONTROL CTRL 60 LT3590 50 VREG SW 3590 TA01a 0.1F GND 40 10 20 40 0 30 50 LED CURRENT (mA) 3590 TA01b 3590f 1 EFFICIENCY (%)LT3590 ABSOLUTE MAXIMUM RATINGS (Note 1) Maximum Junction Temperature........................... 125C Input Voltage (V ) ..................................... 0.3V to 55V IN Storage Temperature Range ...................65C to 150C LED Voltage ............................................... 0.3V to 55V Lead Temperature (Soldering, 10 sec) CTRL Voltage ................................................. 0V to 6.0V SC 8 Package Only ............................................ 300C VREG Voltage ................................................. 0V to 4.0V Operating Junction Temperature Range (Note 2) ...............................................40C to 85C PIN CONFIGURATION TOP VIEW TOP VIEW SW 1 8 V IN CTRL 1 6 VREG GND 2 7 LED GND 2 7 5 LED GND 3 6 VREG SW 3 4 V IN GND 4 5 CTRL SC8 PACKAGE DC PACKAGE 8-LEAD PLASTIC SC70 6-LEAD (2mm 2mm) PLASTIC DFN T = 125C, = 75C/W TO 95C/W T = 125C, = 65C/W TO 85C/W, = 20C/W JMAX JA JC JMAX JA EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT3590EDC PBF LT3590EDC TRPBF LCNZ 6-Lead (2mm 2mm) Plastic DFN 40C to 85C LT3590ESC8 PBF LT3590ESC8 TRPBF LCPB 8-Lead Plastic SC70 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: