LT3799 Datasheet | Linear Technology

.Data Sheet.co.kr Electrical Specifications Subject to Change LT3799 Offline Isolated Flyback LED Controller with Active PFC Features Isolated PFC LED Driver with Minimum Number of External ponents n TRIAC Dimmable n V and V IN OUT Limited Only by External ponents n Active Power Factor Correction (Typical PFC > 0.97) n Low Harmonic Content n No Opto-Coupler Required n Accurate Regulated LED Current (±5% Typical) n Open LED and Shorted LED Protection n Thermally Enhanced 16-lead MSOP Package n DESCRIPTION The LT®3799 is an isolated flyback controller with power factor correction specifically designed for driving LEDs. The controller operates using critical conduction mode allowing the use of a small transformer. Using a novel current sensing scheme, the controller is able to deliver a well regulated current to the secondary side without using an opto-coupler. A strong gate driver is included to drive an external high voltage MOSFET. Utilizing an onboard multiplier, the LT3799 typically achieves power factors of 0.97. The FAULT pin provides notification of open and short LED conditions. The LT3799 uses a micropower hysteretic start-up to efficiently operate at offline input voltages, with a third winding to provide power to the part. An internal LDO provides a well regulated supply for the part’s internal circuitry and gate driver. APPLICATIONS n n Offline 4W to 100W+ LED Applications High DC VIN LED Applications 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 property of their respective owners. Patents pending. TYPICAL APPLICATION TRIAC Dimmable 20W LED Driver LED Current vs Input Voltage 90V TO 150V AC 0.22µF 0.1µF 200Ω 499k 499k 100k 100k 20Ω 4.7p F 10µF VIN 1.15 4:1:1 1.10 1.05 ILED (A) 2k DCM FB 100k 1A 1.00 0.95 0.90 0.85 VIN_SENSE 6.34k VREF 100k 32.4k 40.2k CTRL3 CTRL2 100k NTC 16.2k...