Isolated active PFC LED controller needs no optoisolator

Isolated active PFC LED controller needs no optoisolator

Specifically designed for driving LEDs from a universal input range of 90 to 265 Vac, the LT3799 isolated LED controller offers active power factor correction and standard triac dimming, By using a single-stage PFC flyback topology, the part requires only one FET and one transformer and no optocoupler; most other isolated solutions require an additional 20 to 30 discrete components (for “bleeder” and “damper” circuits, and for secondary-side LED regulation circuitry / optocoupler feedback circuitry).

Features include over 87% efficiency and an active power factor correction of greater than 0.97, which easily meets industrial Department of Energy requirements while also complying with the IEC 61000-3-2 Class C Lighting Equipment Harmonics requirement. The part also offers accurate regulated LED current (±5% typ), while boundary-mode operation improves efficiency and EMI.

The LT3799 can be used with a standard in-wall triac dimmer without any visible flicker. Housed in a thermally enhanced 16-pin MSOP package, the device also offers open-LED and shorted-LED protection. ($2.25 ea/1,000 — stock).

Linear Technology , Milpitas , CA
Sales Office 408-428-2050
www.linear.com