New Industry Products

Linear Tech Isolated Active PFC Off-Line LED Controller Is TRIAC Dimmable & Needs No OPTO Isolator

February 07, 2011 by Jeff Shepard

Linear Technology announced the LT3799, an isolated LED controller with active power factor correction (PFC), specifically designed for driving LEDs from a universal input range of 90 to 265Vac. The LT3799 is optimized for LED applications requiring 4 to over 100W of LED power and also compatible with standard TRIAC in-wall dimmers. The LT3799’s unique current sensing scheme delivers a well regulated current to the secondary side without using an opto-coupler. This not only reduces cost but also improves reliability. It’s single stage PFC regulator design requires minimal external components. Additionally, it’s thermally enhanced MSOP-16E package ensures a simple and compact solution footprint for off-line LED applications.

The LT3799 offers over 86% efficiency, eliminating the need for external heat sinking of the LED driver IC in most applications. Special internal circuitry provides active PFC of up to 0.977, easily meeting industrial Department of Energy (DOE) requirements while also complying with the IEC 61000-3-2 Class C Lighting Equipment Harmonics requirement. The LT3799 can be used with a standard in-wall TRIAC dimmer without any visible flicker. Open and shorted LED protection ensures long-term reliability for a wide range of LED applications.

The LT3799EMSE is available in a thermally enhanced 16-pin MSOP package. Pricing starts at $2.25 each in 1,000 piece quantities and is available from stock. An extended temperature version, or "I" grade, the LT3799IMSE is also available from stock, priced starting at $2.59 each in 1,000 piece quantities.