Cree® XLamp® CXA2520 LED 6-Inch Downlight Reference Design Table of Contents Introduction Introduction........................................................ 1 This application note details the design of a 6-inch Design approach/objectives.................................. 2 downlight that exceeds the performance of typical The 6-step methodology....................................... 2 42‑watt compact fluorescent lamp (CFL) products. 1. Define lighting requirements............................ 2 The design uses Cree’s XLamp CXA2520 LED, a multi- 2. Define design goals........................................ 5 die, high‑flux array optimized for high lumen output 3. Estimate efficiencies of the optical, thermal & applications such as downlights, recessed fixtures electrical systems.......................................... 5 and can lights. The CXA2520 offers lighting-class 4.Calculate the number of LEDs.......................... 8 performance and reliability in a single, easy-to-use 5.Consider all design possibilities........................ 9 component. 6. CLD-AP124 rev 0 application note Complete the final steps: implementation and analysis........................................................ 9 Six-inch downlights are the industry standard indoors Conclusion........................................................ 11 and outdoors in both residential and commercial Special thanks.................................................. 12 applications such as soffits and ceilings, where a wide Bill of materials................................................. 12 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 www. cree.com/Xlamp CXA2520 LED makes it a strong candidate for use in a 6-inch downlight. 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. Copyright in this this document document is is subject subject to to change change without without notice. notice. Cree®, the Cree logo Copyright © © 2010 2013 Cree, Cree, Inc. Inc. All All rights rights reserved. reserved. The The information information in ® Cree, the Cree logo and XLamp are registered trademarks of Cree,specifications, Inc. and XLamp are registered trademarks of Cree, Inc. For product please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 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. Cree, Inc. 4600 Silicon Drive Durham, NC 27703 USA Tel: +1.919.313.5300 XLamp CXA2520 LED 6-inch downlight Reference Design Building on Cree’s reference designs of 6-inch downlights using XLamp CXA2011 and XM-L LEDs, this design demonstrates the possibility of employing the XLamp CXA2520 LED as the light source of a 42‑watt CFL equivalent downlight for use in indoor commercial and residential applications.1 Design approach/objectives In the “LED Luminaire Design Guide”2 Cree advocates a 6-step framework for creating LED luminaires. All Cree reference designs use this framework, and the design guide’s summary table is reproduced below in Table 1. Step Explanation 1. Define lighting requirements • The design goals can be based either on an existing fixture or on the application’s lighting requirements. 2. Define design goals • • Specify design goals, which will be based on the application’s lighting requirements. Specify any other goals that will influence the design, such as special optical or environmental requirements. 3. Estimate efficiencies of the thermal & electrical systems • • • Design goals will place constraints on the optical, thermal and electrical systems. Good estimations of efficiencies of each system can be made based on these constraints. The combination of lighting goals and system efficiencies will drive the number of LEDs needed in the luminaire. 4. Calculate the number of LEDs needed • Based on the design goals and estimated losses, the designer can calculate the number of LEDs to meet the design goals. 5. Consider all design possibilities and choose the best • • With any design, there are many ways to achieve the goals. LED lighting is a new field; assumptions that work for conventional lighting sources may not apply. 6. Complete final steps • • • • • Complete circuit board layout. Test design choices by building a prototype luminaire. Make sure the design achieves all the design goals. Use the prototype to further refine the luminaire design. Record observations and ideas for improvement. optical, Table 1: Cree 6-step framework The 6-step methodology The goal of the design is to show the ease of design and implementation of a 6-inch downlight using one Cree XLamp CXA2520 LED that betters the performance of typical 42‑watt CFL downlights. 1. Define lighting requirements Table 2 shows a ranked list of desirable characteristics for a 6-inch downlight. 1Cree XLamp CXA2011 LED 6-Inch Downlight Reference Design, AP92, www.cree.com/XLamp_ref_des/CXA2011_6in_downlight Cree XLamp XM-L LED 6-Inch Downlight Reference Design, AP93, www.cree.com/xlamp_ref_des/XML_6in_downlight 2LED Luminaire Design Guide, Application Note AP15, www.cree.com/xlamp_app_notes/luminaire_design_guide Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 2 XLamp CXA2520 LED 6-inch downlight Reference Design Importance Critical Characteristics Units Luminous flux (steady-state) lumens (lm) Efficacy lumens per watt (lm/W) Luminous distribution Color uniformity Form factor Price $ Manufacturability Important Lifetime hours Operating temperatures degrees (°C) Operating humidity % relative humidity Correlated color temperature (CCT) K Color rendering index (CRI) 100-point scale Ease of installation Table 2: Some ranked design criteria for an LED downlight Table 3 and Table 4 summarize the ENERGY STAR requirements for luminaires.3 ENERGY STAR REQUIREMENTS Luminaire Type Luminaire Efficacy (Initial) Luminaire Minimum Light Output (Initial) Luminaire Zonal Lumen Density Requirement Downlights: • recessed • surface • pendant • SSL downlight retrofits 42 lm/W ≤ 4.5” aperture: 345 lumens Luminaire shall deliver a minimum of 75% of total initial lumens within the 0-60° zone (axially symmetric about the nadir) > 4.5” aperture: 575 lumens Table 3: ENERGY STAR luminous efficacy, output and zonal lumen density requirements Characteristic Requirements Light source life requirements: all luminaires The LED package(s) / LED module(s) / LED array(s), including those incorporated into LED light engines or GU24 based integrated LED lamps, shall meet the following L70 lumen maintenance life values (refer to Lumen Maintenance Requirements in the next section): • • • 25,000 hours for residential grade indoor luminaires 35,000 hours for residential grade outdoor luminaires 35,000 hours for commercial grade luminaires Lumen maintenance life projection claims in excess of the above requirements shall be substantiated with a TM-21 lumen maintenance life projection report. 3 ENERGY STAR® Program Requirements, Product Specification for Luminaires (Light Fixtures), Eligibility Criteria, Version 1.2, www.energystar.gov/ia/partners/product_specs/program_reqs/Final_Luminaires_V1_2.pdf?7b7d-2473 Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 3 XLamp CXA2520 LED 6-inch downlight Reference Design Characteristic Requirements Lumen maintenance requirements: directional and non-directional luminaires The LED package(s) / module(s) / array(s), including those incorporated into LED light engines or GU24 based integrated LED lamps, shall meet the following L70(6k) rated lumen maintenance life values, in situ: • • L70(6k) ≥ 25,000 hours for residential indoor L70(6k) ≥ 35,000 hours for residential outdoor, or commercial Compliance with the above shall be documented with a TM-21 lumen maintenance life projection report as detailed in TM-21, section 7. The report shall be generated using data from the LM-80 test report for the employed LED package/module/array model (“device”), the forward drive current applied to each device, and the in situ TMPLED temperature of the hottest LED in the luminaire. In addition to LM-80 reporting requirements, the following information shall be reported: • • • • • • sampling method and sample size (per LM-80 section 4.3) test results for each TS and drive current combination description of device including model number and whether device is an LED package, module or array (see Definitions) ANSI target, and calculated CCT value(s) for each device in sample set Δ u’v’ chromaticity shift value on the CIE 1976 diagram for each device in sample set a detailed rationale, with supporting data, for application of results to other devices (e.g. LED packages with other CCTs) Access to the TMPLED for the hottest LED may be accomplished via a minimally sized hole in the luminaire housing, tightly resealed with a suitable sealant if created for purposes of testing. All thermocouple attachments and intrusions to luminaire housing shall be photographed. CCT requirements: all indoor luminaires The luminaire (directional luminaires), or replaceable LED light engine or GU24 based integrated LED lamp (nondirectional luminaires) shall have one of the following nominal CCTs: • • • • • 2700 3000 3500 4000 5000 Kelvin Kelvin Kelvin Kelvin Kelvin (commercial only) The luminaire, LED light engine or GU24 based integrated LED lamp shall also fall within the corresponding 7-step chromaticity quadrangles as defined in ANSI/NEMA/ANSLG C78.377-2008. Color rendering requirements: all indoor luminaires The luminaire (directional luminaires), or replaceable LED light engine or GU24 based integrated LED lamp (nondirectional luminaires) shall meet or exceed Ra ≥ 80. Color angular uniformity requirements: directional solid state indoor luminaires Throughout the zonal lumen density angles detailed above, and five degrees beyond, the variation of chromaticity shall be within 0.004 from the weighted average point on the CIE 1976 (u’,v’) diagram. Color maintenance requirements: solid state indoor luminaires only The change of chromaticity over the first 6,000 hours of luminaire operation shall be within 0.007 on the CIE 1976 (u’,v’) diagram, as demonstrated by either: Source start time requirement: directional and non-directional luminaires Light source shall remain continuously illuminated within one second of application of electrical power. Power factor requirements: directional and non-directional luminaires Total luminaire input power less than or equal to 5 watts: PF ≥ 0.5 Transient protection requirements: all luminaires Ballast or driver shall comply with ANSI/IEEE C62.41.1-2002 and ANSI/IEEE C62.41.2-2002, Class A operation. The line transient shall consist of seven strikes of a 100 kHz ring wave, 2.5 kV level, for both common mode and differential mode. Operating frequency requirements: directional and non-directional luminaires Frequency ≥ 120 Hz • • • the IES LM-80 test report for the employed LED package/array/module model, or as demonstrated by a comparison of luminaire chromaticity data in LM-79 reports at zero and 6,000 hours, or as demonstrated by a comparison of LED light engine or GU24 based integrated LED lamp chromaticity data in LM-82 reports at zero and 6,000 hours. Total luminaire input power greater than 5 watts: Residential: PF ≥ 0.7 Commercial: PF ≥ 0.9 Note: This performance characteristic addresses problems with visible flicker due to low frequency operation and applies to steady-state as well as dimmed operation. Dimming operation shall meet the requirement at all light output levels. Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 4 XLamp CXA2520 LED 6-inch downlight Reference Design Characteristic Requirements Noise requirements: directional and non-directional luminaires All ballasts & drivers used within the luminaire shall have a Class A sound rating. Ballasts and drivers are recommended to be installed in the luminaire in such a way that in operation, the luminaire will not emit sound exceeding a measured level of 24 BA. Table 4: ENERGY STAR luminaire requirements 2. Define design goals Typical 42-W CFL downlights use a lamp that produces about 3100 lm, but luminaire light output is only about 2000 lm, giving a fixture efficiency of about 65%. We chose the design goals for this project, shown in Table 5, to better this performance using less energy over a longer lifetime. We chose a 50° cutoff angle as a good balance between maximizing direct illumination and minimizing glare. As shown in Figure 1, the cutoff angle is measured from the vertical axis of the luminaire outward to the point at which the brightness of the light source is no longer visible. Light source Cutoff angle Figure 1: Cutoff angle Characteristic Light output Luminaire efficacy Cutoff angle Lifetime Unit Minimum Goal Target Goal lm 2000 > 2000 lm/W 75 > 75 degrees 50 50 hours 35,000 50,000 CCT K 3000 3000 CRI 100-point scale 80 > 80 Power W Power factor 26 < 26 0.9 > 0.9 Table 5: Design goals 3. Estimate efficiencies of the optical, thermal & electrical systems We used Cree’s Product Characterization Tool (PCT) tool, shown in Figure 2, to determine the drive current for the design.4 For the 2000-lumen target, we estimated 90% optical efficiency and 87% driver efficiency. We also estimated a solder point temperature (TSP) of 45 °C. 4PCT is available at: pct.cree.com Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 5 XLamp CXA2520 LED 6-inch downlight LED System Comparison Rep Reference Design 1 System: 2,000 Target Lumens : LED 1 $ Price SYS # LED SYS lm tot 0.520 0.530 0.540 0.550 0.600 0.650 0.700 2 2 2 2 1 1 1 Flux LED 2 Model Cree XLamp CXA2520 {EZW} Current (A) Model Q2 [2100] 3800.65 3856.12 3911.04 3965.44 2114.42 2239.96 2359.8 90 Optical Efficiency: Tsp (ºC) SYS W 43.447 44.35 45.254 46.16 25.351 27.637 29.937 45 Flux Cree XLamp MT-G2: 36V {EZW} 30F 90% [694] SYS lm/W $ Price SYS # LED SYS lm tot 87.5 86.9 86.4 85.9 83.4 81 78.8 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A Tj (ºC) SYS W #N/A #N/A #N/A #N/A #N/A #N/A #N/A 8 SYS l #N/A #N/A #N/A #N/A #N/A #N/A #N/A ThisPCT document is provided informational andand is not driving a warranty current or a specification. For product specifications, please see the data Figure 2: view of thefornumber ofpurposes LEDs only used Copyright © 2009-2012 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree, the Cree logo a The PCT shows that, at 600 mA, one CXA2520 LED provides sufficient light output to meet the design goal. Thermal Requirements We used a commercially available heat sink/housing, shown in Figure 3, for the 6-inch downlight in this reference design.5 The heat sink/housing is made of anodized forged aluminum. The heat sink/housing is part of a kit that includes a cover glass and front trim ring. Figure 3: Top (left), side (center) and bottom (right) views of heat sink/housing We performed thermal simulations to verify this thermal design is sufficient. Figure 4 shows the thermal simulation results for the design. The simulated TSP is 46 °C. 5 Model ADC 10, Xing Yi Lighting, www.xingyilight.com/main.asp Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 6 XLamp CXA2520 LED 6-inch downlight Reference Design Thermal Simulation / Measurement •Ab to the •Th ~4 •C Thermal Simulation Tsp ~45C, Figure 4: Thermal simulation of CXA2520 downlight Driver Copyright © 2010, Cree, Inc. Cree Proprietary & Confidential The driver for this downlight can be located above the ceiling, apart fromTsp the downlight, andT2 there is no driver T3 size limit. 6 is a slightly modified version We used a universal input voltage constant-current driver, shown in Figure 40.8℃5. The driver 38.7℃ of a commercially available driver model. Thermal Simulation Tsp ~45C, Copyright © 2010, Cree, Inc. Cree Proprietary & Confidential •About 75% of the 26W input power will convert to heat and need sufficient heatsink to dissipate the heat •Thermal measurement by thermal couple: Tsp ~41C •Calculated Tj ~59C pg. 9 Figure 5: CXA2520 downlight driver Secondary Optics We used a custom reflector to achieve the desired 50° cutoff angle.7 The reflector, shown in Figure 6, is about 90% optically efficient and fits within the heat sink/housing. The reflector may also be suitable for use in spotlights and track luminaires. 6 Model SP-22V2A PFC, Shenzhen SGQ Electronic Technology Co. Ltd, sgqsz.cn.gongchang.com 7Model 5711-E, Nata Lighting Company Limited, www.nata.cn/ Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 7 XLamp CXA2520 LED 6-inch downlight Reference Design Figure 6: CXA2520 downlight reflector 4. Calculate the number of LEDs The purpose of this reference design is to show that a single XLamp CXA2520 LED can deliver equivalent lighting utility and superior performance compared to existing 42-W CFL downlights on the market. The CXA2520 LED is a multi-chip LED package that can offer the required lumens with new levels of LED-to-LED color consistency and efficiency. The new XLamp CXA2520 LED is 15% brighter than the original CXA2011,8 which can enable superior LED lighting designs even more quickly. We selected a Warm White LED for this reference design, shown highlighted in yellow in Table 6. By choosing an LED from a mid-level flux bin, we ensured that the design uses an LED that is readily available. Color CCT Range 4000K 3500K EasyWhite 3000K 2700K Base Order Codes Min. Luminous Flux @ 550 mA 2-Step Order Code 4-Step Order Code Group Flux (lm) @ 85 °C Flux (lm) @ 25 °C* Q2 2100 2379 Q4 2260 2560 R2 2420 2741 CXA2520-0000-000N00R240H CXA2520-0000-000N00R240F P4 1965 2226 CXA2520-0000-000N00P435H CXA2520-0000-000N00P435F Q2 2100 2379 Q4 2260 2560 P4 1965 2226 Q2 2100 2379 P2 1830 2073 P4 1965 2226 Q2 2100 2379 Chromaticity Region Chromaticity Region CXA2520-0000-000N00Q240H 40H 35H CXA2520-0000-000N00Q440H CXA2520-0000-000N00Q235H CXA2520-0000-000N00Q240F 40F 35F CXA2520-0000-000N00Q435H 30H CXA2520-0000-000N00P430H CXA2520-0000-000N00Q230H CXA2520-0000-000N00P427H CXA2520-0000-000N00Q227H CXA2520-0000-000N00Q235F CXA2520-0000-000N00Q435F 30F CXA2520-0000-000N00P227H 27H CXA2520-0000-000N00Q440F CXA2520-0000-000N00P430F CXA2520-0000-000N00Q230F CXA2520-0000-000N00P227F 27F CXA2520-0000-000N00P427F CXA2520-0000-000N00Q227F Table 6: CXA2520 LED order codes 8 At 1 A, junction temperature (TJ) = 85 °C Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 8 XLamp CXA2520 LED 6-inch downlight Reference Design 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 easyto-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 LED. CCTs from 2700 K to 5000 K and lumen output up to 4500 lm9 is available, providing the flexibility to offer a 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. 2. We attached the CXA2520 LED to the heat sink with a small amount of thermally conductive epoxy.10 Thermally conductive compound can also be used.11 3. After the thermal epoxy cured, we fed the driver output wires through the heat sink and soldered them to the LED, following the recommendations in Cree’s Soldering and Handling Application Note for the CXA2520 LED.12 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. 9 At 61 W, 85 °C 10We used Silanex Technology ST0903. www.silanex.com/Product03.htm 11Refer 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 12Cree XLamp CXA Family LEDs Soldering and Handling, Application Note AP74, www.cree.com/xlamp_app_notes/CXA_SH Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 9 XLamp CXA2520 LED 6-inch downlight Reference Design Results Thermal Results Cree verified the board temperature with a thermocouple to confirm that the thermal dissipation performance of the heat sink aligns with our simulations. The measured solder point temperature was 41 °C. Based on the measured solder point temperature, the TJ can be calculated as follows. TJ = TSP + (LED power * LED thermal resistance) TJ = 41 °C + (26 W * 0.8 °C/W) TJ = 62 °C This thermal performance is in line with the thermal simulation. Estimated LED Lifetime Based on thousands of hours of long-term testing of the CXA2011 LED at higher temperatures than the measured 41 °C TSP of the CXA2520 downlight, Cree expects an L70 lifetime significantly longer than 50,000 hours. 42-W CFL lamps typically have lifetimes ranging from 10,000 to 12,000 hours, so the 4 to 5 times longer lifetime of the CXA2520 downlight offers solid maintenance cost savings. Optical and Electrical Results We tested the downlight in a 1.5-meter sphere after a 60-minute stabilization time to obtain the results in Table 7.13 As the table shows, the downlight meets the target goals for the design. The 2140-lm light output positions this downlight in the upper reaches of the light output of downlights currently on the market. The downlight also meets the ENERGY STAR light output, efficacy, power factor, CCT and CRI requirements. Characteristic Luminous flux Luminaire efficacy Unit Downlight lm 2140 lm/W 82 Cutoff angle ° 50 CCT K 3046 CRI 100-point scale 80 W 26.1 Power Power factor 0.95 Table 7: CXA2520 downlight steady-state results We also tested the intensity distribution of the downlight. Figure 7 shows an even intensity distribution with a 56° beam angle. The figure also shows the 50° cutoff angle that was a goal of this effort. 13 Testing was performed at the Cree’s Shenzhen Technology Center. An IES file for the downlight is available at: www.cree.com/ xlamp_app_notes/CXA2520_downlight_ies Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 10 XLamp CXA2520 LED 6-inch downlight Reference Design Cutoff angle = 50° Figure 7: Angular luminous intensity distribution of CXA2520 downlight Table 8 shows the center beam illuminance of the CXA2520 downlight at various distances from the light source. Height Center Beam Illuminance Beam Width 0.5 m 1.7 ft 926 fc 9,970 lx 0.6 m 1.8 ft 1.0 m 3.3 ft 231 fc 2,492 lx 1.1 m 3.5 ft 1.5 m 5.0 ft 103 fc 1,107 lx 1.6 m 5.3 ft 2.0 m 6.6 ft 58 fc 623 lx 2.2 m 7.1 ft 2.5 m 8.3 ft 37 fc 399 lx 2.7 m 8.9 ft 3.0 m 9.9 ft 26 fc 279 lx 3.2 m 10.6 ft Table 8: CXA2520 downlight illuminance – 56° beam angle Conclusion This reference design illustrates the ease of developing a very capable 6-inch downlight based on the Cree XLamp CXA2520 LED. The small number of steps to assemble the downlight illustrates the simple construction the CXA2520 Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 11 XLamp CXA2520 LED 6-inch downlight Reference Design LED enables, lowering system cost. Simplicity of use and lighting-class performance make the Cree XLamp CXA2520 LED an attractive design option for an LED-based 6-inch downlight. Special thanks Cree would like to acknowledge and thank the following partner companies for collaborating in the successful prototyping of this downlight. • Shenzhen SGQ Electronic Technology Co. Ltd. • Nata Lighting Company Limited - www.nata.cn Bill of materials Component Order Code/Model Number Company Web Link Driver SP-22V2A PFC Shenzhen SGQ Electronic Technology Co. Ltd. sgqsz.cn.gongchang.com Heat sink/housing, cover glass, front trim ring kit ADC 10 Xing Yi Lighting www.xingyilight.com/main.asp LED CXA2520-0000-000N00Q230H Cree, Inc. www.cree.com/cxa2520 Reflector 5711-E Nata Lighting Company Limited www.nata.cn Thermal epoxy ST0903 Silanex Technology Pte Ltd. www.silanex.com/Product03.htm Table 9: Bill of materials for CXA2520 6-inch downlight 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. Copyright © 2013 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, the Cree logo and XLamp® are registered trademarks of Cree, Inc. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 12