Ref design eases high-efficiency LED apps dev't

Configured in size and features for MR16 LED replacements, the first reference design describes a built and tested 3W to 5W LED driver solution for driving high-brightness LEDs. The second design is targeted at designers looking to achieve compliance with the Energy Star 1.1 requirements for solid-state lighting in residential luminaire applications and describes a built and tested off-line GreenPoint solution for an isolated 8W constant current LED driver.

Each of the new reference designs addresses all of the functional blocks needed to create a complete application and is available as a package that includes description, schematics, BOM, Gerber files and evaluation guidelines.

The MR16 reference design is based on a buck-boost topology using ON Semiconductor's NCP3065 switching regulator operating at around 150KHz in a non-isolated constant current configuration. Suitable for 12Vac or 12Vdc applications such as track lighting, automotive lighting and landscape lighting, the circuit delivers flat current regulation irrespective of input line and output LED voltage variation. It also features a unique auto-detect circuit that allows input from a 12Vdc or 12Vac supply while maintaining the targeted output current. A reference design evaluation board is available on the ON Semiconductor Website.

ON Semiconductor's off-line LED Driver GreenPoint reference design for Energy Star residential LED luminaires has been optimized to drive between one and eight high-power LEDs in applications such as portable desk lamps, under-cabinet lighting and outdoor porch lights. This reference design uses a novel circuit configuration to achieve a power factor of >0.85 at 115Vac without the addition of an extra passive power factor correction network. This reduces components count and easily meets the residential power factor requirements. The design operates from a 90Vac-265Vac universal input and is built around the ON Semiconductor NCP1014 switcher IC, which integrates a fixed-frequency current mode controller with a 700V MOSFET.

"The market for solid-state lighting continues to grow as new and traditional manufacturers look to capitalize on the performance, cost, reliability and efficiency benefits that LEDs offer over conventional alternatives," said Laurent Jenck, ON Semiconductor's marketing director for power supply applications. "These new GreenPoint reference designs allow designers of new and emerging lighting applications to dramatically reduce development times by providing a proven and tested solution to driving high-brightness LEDs as efficiently as possible."