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cree, the cree logo and Xlamp are registered trademarks of cree, Inc.

6-Inch Downlight Reference Design

cree, Inc.

4600 Silicon Drive

Durham, Nc 27703

USa Tel: +1.919.313.5300

AppLICAtIon notE

warranty information, please contact cree Sales at sales@cree.com. other trademarks, product and company names are the property of their

respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association.

IntRoDuCtIon

This application note details the design of a 6-inch

downlight that exceeds the performance of typical

42‑watt compact fluorescent lamp (CFL) products.

The design uses cree’s Xlamp cXa2520 leD, a multi-

die, high‑flux array optimized for high lumen output

applications such as downlights, recessed fixtures

and can lights. The cXa2520 offers lighting-class

performance and reliability in a single, easy-to-use

component.

Six-inch downlights are the industry standard indoors

and outdoors in both residential and commercial

applications such as soffits and ceilings, where a wide

beam pattern is desirable. with a typical light output

range from 1500 to 3600 lumens, the flexibility, high

performance and ease of use offered by the Xlamp

cXa2520 leD makes it a strong candidate for use in a

6-inch downlight.

tAbLE of ContEnts

Introduction....................................................... 1

Design approach/objectives ................................. 2

The 6-step methodology...................................... 2

1. Define lighting requirements........................... 2

2. Define design goals ....................................... 5

3. Estimate efficiencies of the optical, thermal &

electrical systems ......................................... 5

4. calculate the number of leDs ......................... 8

5. consider all design possibilities ....................... 9

6. Complete the final steps: implementation and

analysis ....................................................... 9

conclusion....................................................... 11

Special thanks ................................................. 12

Bill of materials ................................................ 12

Reliance on any of the information provided in this Application Note is at the user’s sole risk. Cree and its affiliates make no warranties or representations

about, nor assume any liability with respect to, the information in this document or any leD-based lamp or luminaire made in accordance with this

reference design, including without limitation that the lamps or luminaires will not infringe the intellectual property rights of cree or a third party.

luminaire manufacturers who base product designs in whole or part on any cree application Note or reference Design are solely responsible for the

compliance of their products with all applicable laws and industry requirements.