CREE CXA2520-0000-000N00P435F 6-inch downlight reference design Datasheet

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.
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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].
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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].
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