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XLamp CXa2520 LED

6-inCh DownLight

REfEREnCE DEsign

of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at sales@cree.com.

5.

ConsIDER ALL DEsIgn possIbILItIEs

There is a multiplicity of ways to design an leD-based downlight. This reference design aims to show that a single easy-

to-use cXa2520 leD enables a downlight offering superior performance.

This design presents a number of desirable performance‑related benefits that are results of the XLamp CXA2520 LED

package. Because the cXa2520 leD uses easywhite™ technology, leD-to-leD color consistency can be held to within

two or four McAdam ellipses for any given CCT, depending on the order code. The CXA2520 LED is binned at 85 °C, so

the ccT will be as faithful as possible to the system operating environment. These component features allow for new

levels of specification accuracy.

However, the primary purpose of this reference design is to show how simple and straightforward it is to design

with cree’s Xlamp cXa2520 leD. This application note is not intended to show the only way to do this, but instead

demonstrate the ease of implementation with this set of engineering constraints. certainly numerous other successful

solutions are possible.

The performance range of the Xlamp cXa2520 leD enables a wide variety of luminaires that all use a single cXa2520

variety of luminaires that use a single LED light source and reflector. This flexibility is enhanced by the XLamp CXA2530

LED, which has the same physical dimensions and optical source size as the CXA2520 and offers even more design

possibilities.

6.

CompLEtE thE fInAL stEps: ImpLEmEntAtIon AnD AnALysIs

Using the methodology described above, we determined a suitable combination of an leD, components and drive

conditions. This section describes how cree assembled the downlight and shows the results of the design.

prototyping Details

1. We verified the component dimensions to ensure a correct fit.

3. after the thermal epoxy cured, we fed the driver output wires through the heat sink and soldered them to the leD,

4. We tested the connection by applying power and verified the LED lit up.

5. We positioned the reflector on the LED, added the cover glass and secured both parts to the heat sink with the

screw-on front trim ring.

6. We performed final testing.

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At 61 W, 85 °C

10 we used Silanex Technology ST0903. www.silanex.com/product03.htm

11 refer to cree’s chemical compatibility application note for compounds that are safe to use with cree leDs.

cree Xlamp leD chemical compatibility application Note, ap63, www.cree.com/products/pdf/Xlamp_chemical_comp.pdf

12 cree Xlamp cXa Family leDs Soldering and Handling, application Note ap74, www.cree.com/xlamp_app_notes/cXa_SH