Linear introduces isolated LED controller

Photocoupler

Linear Technology Corporation has an active power factor correction (PFC) isolated LED controller , the LT3799 , designed to drive LEDs for a universal input range of 90VAC to 265VAC. The LT3799 is optimized for LED applications that require 4W to 100W+ LED power and is compatible with standard TRIAC wall dimmers. The LT3799 's unique current sensing solution delivers a well-regulated current to the secondary without the need for an optocoupler. This not only reduces costs, but also improves reliability. The device's single-stage PFC regulator design requires very few external components. In addition, its thermally enhanced MSOP-16E package ensures a compact and compact footprint solution for off-line LED applications.

The LT3799 delivers over 86% efficiency, eliminating the need for external thermal dissipation in LED driver ICs in most applications. Special internal circuitry provides up to 0.977 active PFC, making it easy to meet US Department of Energy industry requirements while also complying with IEC 61000-3-2 Class C lighting harmonic requirements. The LT3799 can be used with standard wall TRIAC dimmers without any visible flicker. For a wide range of LED applications, open and shorted LED protection ensures long-term reliability.

Photo caption: Isolated Active PFC Offline LED Controller

Performance Summary: LT3799

· Isolated PFC LED driver with the lowest number of external components

· VIN and VOUT are only limited by external components

· Can be used with standard TRIAC dimmers

· Active power factor correction

· Low harmonic content

· No optocoupler required

· Accurate (±5%) regulated LED current

· Open and shorted LED circuit protection

· Thermally Enhanced 16-Lead MSOP Package