The LT3799EMSE-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 LT3799EMSE-1 typically achieves power factors of 0.97. The FAULT pin provides notification of open and short LED conditions.
The LT3799EMSE-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.
TRIAC DimmableLED Current RegulationLT3799YES±10%LT3799-1NO±5%Feature
- Isolated PFC LED Driver with Minimum Number of External Components
- TRIAC Dimmable
- 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
Applications
- Offline 4W to 100W+ LED Applications
- High DC VIN LED Applications
(Picture: Pinout)
