LT3799-1 - Offline Isolated Flyback LED Controller with Active PFC

The LT®3799-1 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 LT3799-1 typically achieves power factors of 0.97. The FAULT pin provides notification of open and short LED conditions. The LT3799-1 offers improved line regulation over the LT3799, but is not designed for use with a TRIAC dimmer.

The LT3799-1 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.

Features
  • Isolated PFC LED Driver with Minimum Number of External Components
  • VIN and VOUT Limited Only by External Components
  • Active Power Factor Correction (Typical PFC > 0.97)
  • Low Harmonic Content
  • No Opto-Coupler Required
  • Accurate Regulated LED Current (±5% Typical)
  • Open LED and Shorted LED Protection
  • Thermally Enhanced 16-Lead MSOP Package
Typical Application

Applications
  • Offline 4W to 100W+ LED Applications
  • High DC VIN LED Applications
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT3799EMSE-1#PBFMS-16EE$3.22$2.25
LT3799EMSE-1#TRPBFMS-16EE$2.31
LT3799IMSE-1#PBFMS-16EI$3.70$2.59
LT3799IMSE-1#TRPBFMS-16EI$2.65
Demo Boards
Part NumberDescriptionPrice
DC1816BLT3799EMSE-1 Demo Board I Offline Isolated Flyback LED Driver with PFC – 90-305VAC input to 36Vout (nom) @ 3A$250.00
DC1947ALT3799EMSE-1 Demo Board u Offline Isolated Flyback LED Driver with PFC$175.00
Datasheet
Reliability Data
LTspice
Related Product
LT3799-1 - Offline Isolated Flyback LED Controller with Active PFC
R530 - Reliability Data
LT3799-1 Footprints and Symbols
LT3799-1 Demo Circuit - Offline Isolated Flyback LED Controller with Active PFC (277VAC to 3A/36V)