LT3799-1 Offline Isolated Flyback LED Controller with Active PFC FeaT DescripT n Isolated PFC LED Driver with Minimum Number of The LT 3799-1 is an isolated flyback controller with power External Components factor correction specifically designed for driving LEDs. n V and V Limited Only by External Components The controller operates using critical conduction mode IN OUT n Active Power Factor Correction (Typical PFC > 0.97) allowing the use of a small transformer. Using a novel n Low Harmonic Content current sensing scheme, the controller is able to deliver a n No Opto-Coupler Required well regulated current to the secondary side without using n Accurate Regulated LED Current (5% Typical) an opto-coupler. A strong gate driver is included to drive n Open LED and Shorted LED Protection an external high voltage MOSFET. Utilizing an onboard n Thermally Enhanced 16-Lead MSOP Package multiplier, the LT3799-1 typically achieves power factors of 0.97. The FAULT pin provides notification of open and Ta short LED conditions. The LT3799-1 offers improved line regulation over the LT3799, but is not designed for use n Offline 4W to 100W+ LED Applications with a TRIAC dimmer. n High DC V LED Applications IN The LT3799-1 uses a micropower hysteretic start-up to L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the efficiently operate at offline input voltages, with a third property of their respective owners. Patents pending. winding to provide power to the part. An internal LDO provides a well regulated supply for the parts internal circuitry and gate driver. Typical Ta 20W LED Driver LED Current vs Input Voltage 1.20 1.15 100k 90V 20 1.10 TO 150V 4:1:1 0.22F 499k AC 100k 4.7pF 1.05 10F 499k 2k 1.00 1A 100k 0.95 V DCM IN V FB 170V IN SENSE 0.90 4.99k 560F LT3799-1 6.34k 0.85 2 0.80 V REF 90 100 110 120 130 140 150 20W 20 33V 100k 32.4k 40.2k CTRL3 GATE LED V (V ) IN AC 37991 TA01b POWER CTRL2 SENSE INTV CTRL1 CC 0.05 100k 4.7F NTC 15.8k 2.2nF GND + FAULT FAULT CT COMP COMP 37991 TA01a 0.1F 0.1F 37991fa 1 For more information www.linear.com/LT3799-1 I (A) LED ion pplica ions pplica ion uresLT3799-1 Ta e MaxiMMu Tar in p Fc T (Note 1) TOP VIEW V , FAULT .................................................................32V IN 1 V CTRL1 16 IN SENSE CTRL2 2 15 SENSE GATE, INTV ...........................................................12V CC 3 CTRL3 14 GATE V 17 CTRL1, CTRL2, CTRL3, V , COMP ................4V 4 13 INTV REF IN SENSE CC 5 GND FAULT 12 NC + FB, CT, V COMP , ...................................................3V CT 6 11 V REF, IN + 7 COMP 10 DCM SENSE ......................................................................0.4V COMP 8 9 FB DCM .......................................................................3mA MSE PACKAGE 16-LEAD PLASTIC MSOP Maximum Junction Temperature .......................... 125C = 50C/W, = 10C/W JA JC Operating Temperature Range (Note 2) EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB LT3799-1E .......................................... 40C to 125C LT3799-1I ........................................... 40C to 125C Storage Temperature Range .................. 65C to 150C Dro er Fni MTa (