LT3761/LT3761-1 60V LED Controller with IN Internal PWM Generator Fea T Descrip T n 3000:1 True Color PWM Dimming for LEDs The LT 3761/LT3761-1 is a DC/DC controller designed to n Wide V Range: 4.5V to 60V operate as a constant-current source and constant-voltage IN n Rail-to-Rail Current Sense Range: 0V to 80V regulator. It features a programmable internal PWM dim- n Programmable PWM Dimming Signal Generator ming signal. The LT3761/LT3761-1 is ideally suited for n Constant Current (3%) and Constant-Voltage driving high current LEDs, but also has features to make (2%) Regulation it suitable for charging batteries and supercapacitors. n Analog Dimming The fixed frequency, current mode architecture results in n Drives LEDs in Boost, SEPIC, Inverting, Buck Mode, stable operation over a wide range of supply and output Buck-Boost Mode, or Flyback Configuration voltages. A voltage feedback pin serves as the input for n Output Short-Circuit Protected Boost several LED protection features, and also makes it possible n Open LED Protection for the converter to operate as a constant-voltage source. n Adjustable Switching Frequency: 100kHz to 1MHz A frequency adjust pin allows the user to program the n Programmable V UVLO with Hysteresis frequency from 100kHz to 1MHz to optimize efficiency, IN n C/10 Indication for Battery Chargers performance or external component size. The LT3761-1 n Low Shutdown Current: <1A can be synchronized to an external clock. n Thermally Enhanced 16-Lead MSOP Package The LT3761/LT3761-1 senses output current at the high n Open LED Status Pin (LT3761) side or at the low side of the load. The PWM input can be n Frequency Synchronization (LT3761-1) configured to self-oscillate at fixed frequency with duty ratio programmable from 4% to 96%. When driven by a T an external signal, the PWM input provides LED dimming n ratios of up to 3000:1. The CTRL input provides additional High Voltage LED Strings >100V with Ground analog dimming capability. Referred Current Sense n L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Grounded Anode LEDs True Color PWM is a trademark of Analog Devices, Inc. All other trademarks are the property of n Accurate Current Limited Voltage Regulators their respective owners. Protected by U.S. Patents including 7199560, 7321203. Typical a T 94% Efficient Boost LED Driver for Automotive PWM Dimming Waveforms at Headlamp with 25:1 Internal PWM Dimming Various DIM Voltage Settings 10H V IN 8V TO V = 7.7V DIM 2.2F 60V 499k DC = 96% PWM 2 V IN 1M 2.2F 0.25 1A GATE EN/UVLO V = 4V 4 DIM V REF DC = 50% SENSE 90.9k PWM 1M I LED LT3761 10m 16.9k V = 1.5V 1A/DIV DIM CTRL DC = 10% PWM GND INTV CC 140k V = 0.4V DIM 100k FB DC = 4.3% PWM 60W ISP OPENLED LED 37611 TA01b ISN 0.5ms/DIV DIM DIM/SS STRING 124k PWM PWMOUT V RT INTV 0.01F C CC 47nF 28.7k 5.1k INTV CC 300Hz 350kHz 4.7nF 1F 37611 TA01a 37611fb For more information www.linear.com/LT3761 1 ion pplica ions pplica ion uresLT3761/LT3761-1 a Te m aximum r a T p in c F T (Note 1) TOP VIEW V , EN/UVLO ............................................................60V IN PWMOUT 1 16 GATE FB 2 15 SENSE ISP, ISN .....................................................................80V ISN 3 14 V IN ISP 4 17 13 INTV CC INTV ...................................................V + 0.3V, 9.6V CC IN V 5 12 EN/UVLO GND C CTRL 6 11 RT GATE, PWMOUT ................................................ (Note 2) V 7 10 DIM/SS REF CTRL, OPENLED ........................................................15V PWM 8 9 OPENLED OR SYNC MSE PACKAGE FB, PWM, SYNC .......................................................9.6V 16-LEAD PLASTIC MSOP V , V ......................................................................3V C REF T = 125C (E-, I-GRADES), T = 150C (H-GRADE), JMAX JMAX = 43C/W, = 4C/W JA JC RT, DIM/SS ..............................................................1.5V EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB SENSE ......................................................................0.5V Operating Ambient Temperature Range (Notes 3, 4) LT3761E/LT3761E-1 ............................... 40 to 125C LT3761I/LT3761I-1 ................................. 40 to 125C LT3761H ................................................40 to 150C Storage Temperature Range .................. 65C to 150C o r Der i n F T