Cree® XLamp® High‑CRI MR16 Reference Design Table of Contents Introduction Introduction....................................................................................1 Previous Cree reference designs demonstrated the viability of Design approach/objectives.........................................................2 LED technology in halogen MR16 replacement lamps of up to The 6-step methodology................................................................2 50‑watt equivalents.1 These demonstration designs provided the 1. Define lighting requirements.................................................2 same or better range of lumen output, beam angles and center 2. Define design goals................................................................4 beam candle power (CBCP) as traditional halogen lamps while 3. Estimate efficiencies of the optical, thermal & electrical reducing energy consumption by up to 80% and extending the systems...................................................................................5 service life of the lamps by a factor of over 20. The weakness in 4. Calculate the number of LEDs...............................................6 these previous works (relative to halogen technology) was color 5. Consider all design possibilities............................................7 rendering index (CRI). Previous designs generally had a CRI of 6. Complete the final steps: implementation and analysis......7 around 82, which is generally considered adequate for all but Conclusion....................................................................................13 the most demanding artwork, retail and hospitality applications. Bill of materials............................................................................14 This new work expands on the previous designs, extending these CLD-AP162 rev 0C Application Note same advantages to the 90+ CRI range and thereby eliminating the last remaining technical advantage of halogen technology in www.cree.com/Xlamp these demanding applications. 1 Cree XLamp MT-G MR16 Reference Design Cree XLamp XM-L EZW MR16 Reference Design Cree XLamp XP-E MR16 Reference Design Cree XLamp XB-D MR16 Reference Design Cree XLamp MK-R MR16 Reference Design Cree XLamp XQ-D MR16 Reference Design 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 © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. Cree, Inc. 4600 Silicon Drive Durham, NC 27703 USA Tel: +1.919.313.5300 1 XLamp ® LED high‑CRI MR16 Reference Design This reference design demonstrates how the Cree XLamp® XM-L2, MK-R and MT-G2 LEDs can each be used as the light source of an MR16 lamp having a CRI value greater than 90. Taken together, these three lamps provide light output and light quality equivalent to that provided by halogen lamps operating at a range of commonly available power levels. Design approach/objectives In the “LED Luminaire Design Guide” Cree advocates a six‑step framework for creating LED luminaires and lamps. All Cree reference designs use this framework, and the design guide’s summary table is reproduced below. Table 1: Cree 6-step framework 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 optical, 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. The 6-step methodology The goal of this design is to create three LED-based retrofit MR16 lamps that show the performance, especially color rendering, available from the XLamp XM‑L2, MK-R and MT‑G2 LEDs and match the light output of 20-, 35- and 50‑watt halogen lamps. 1. Define lighting requirements Table 2 shows a ranked list of desirable characteristics for an MR16 lamp reference design to address. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Table 2: Ranked design criteria for an MR16 lamp Importance Critical Characteristics Units Light intensity - CBCP candelas (cd) Beam angle - full width half maximum (FWHM) degrees (°) Illuminance distribution footcandles (fc)/lux (lx) Power watts (W) Luminous flux lumens (lm) Efficacy lumens per watt (lm/W) Form factor Important Price $ Lifetime hours Operating temperature °C Correlated color temperature (CCT) K CRI 100-point scale Manufacturability Table 3 summarizes the ENERGY STAR® requirements for all integral LED lamps.2 Table 3: ENERGY STAR requirements for all lamps Characteristic Requirements Lamp must have one of the following designated CCTs (per ANSI C78.377-2008) consistent with the 7-step chromaticity quadrangles and Duv tolerances below. CCT and Duv Nominal CCT Target CCT (K) and Tolerance 2700 K 3000 K 3500 K 4000 K 2725 ± 145 3045 ± 175 3465 ± 245 3985 ± 275 Target Duv and Tolerance 0.000 ± 0.000 ± 0.000 ± 0.001 ± 0.006 0.006 0.006 0.006 Color maintenance The change of chromaticity over the minimum lumen maintenance test period (6,000 hours) shall be within 0.007 on the CIE 1976 (u’, v’) diagram. CRI Minimum CRI (Ra) of 80. R9 value must be greater than 0. Allowable lamp bases Must be a lamp base listed by ANSI. Power factor Lamp power < 5 W and low voltage lamps: no minimum power factor is required Lamp power > 5 W: power factor must be > 0.70 Note: Power factor must be measured at rated voltage. Minimum operating temperature -20 °C or below LED operating frequency ≥ 120 Hz Note: This performance characteristic addresses problems with visible flicker due to low frequency operation and applies to steadystate as well as dimmed operation. Dimming operation shall meet the requirement at all light output levels. Electromagnetic and radio frequency interference Must meet appropriate FCC requirements for consumer use (FCC 47 CFR Part 15) Audible noise Class A sound rating Transient protection Power supply shall comply with IEEE C62.41-1991, 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 voltage Lamp shall operate at rated nominal voltage of 120, 240 or 277 VAC, or at 12 or 24 VAC or VDC. Table 4 summarizes the ENERGY STAR requirements for replacement MR16 lamps.3 2 3 ENERGY STAR Program Requirements for Integral LED Lamps Eligibility Criteria – Version 1.4 Ibid., Table 7C Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Table 4: ENERGY STAR requirements for MR16 lamps Criteria Item Requirements Definition Directional lamp means a lamp having at least 80% light output within a solid angle of ∏ sr (corresponding to a cone with angle of 120°) Minimum luminous efficacy Lamp diameter < 20/8 inch: 40 lm/W Lamp diameter > 20/8 inch: 45 lm/W Color spatial uniformity The variation of chromaticity within the beam angle shall be within 0.006 from the weighted average point on the CIE 1976 (u’, v’) diagram. Maximum lamp diameter Not to exceed target lamp diameter Maximum overall length (MOL) Not to exceed MOL for target lamp Minimum center beam intensity PAR and MR16 lamps MR16 lamps Link to online tool at www.energystar.gov/ia/products/lighting/iledl/IntLampCenterBeamTool.zip Lumen maintenance > 70% lumen maintenance (L70) at 25,000 hours of operation Rapid-cycle stress test Cycle times must be 2 minutes on, 2 minutes off. Lamp will be cycled once for every 2 hours of L70 life. Table 5 shows performance data for several halogen MR16 lamps, gleaned from data sheets available publicly. Table 5: Halogen MR16 comparison data Lamp Power (W) Luminous Flux (lm) Efficacy (lm/W) CRI CBCP (cd) Beam Angle (°) Lifetime (B50 hours) Estimated Yearly Energy Cost ($) 20-W Halogen MR16 20 200 10 100 1000 24 3000 2.41 35-W Halogen MR16 35 540 15 100 1750 24 3000 4.22 50-W Halogen MR16 50 790 16 100 2500 24 3000 6.02 Source 2. Define design goals The aim of this project is 20-, 35- and 50‑W equivalent MR16 lamps with an 25° beam angle using the XLamp XM-L2, MK-R and MT-G2 LEDs, respectively. We used the ENERGY STAR Center Beam Intensity Benchmark Tool to determine the CBCP such lamps need to provide. Table 6 shows the design goals for this project. Table 6: Design goals Minimum Goal Characteristic Unit XM-L2 20-W MR16 MK-R 35-W MR16 Target Goal MT-G2 50-W MR16 XM-L2 20-W MR16 MK-R 35-W MR16 MT-G2 50-W MR16 Light output lm 160 320 440 220 400 495 CBCP - 25° beam angle cd 876 1601 2323 > 876 > 1601 > 2323 lm/W 40 40 40 55 50 45 W 4 8 11 <4 <8 < 11 Efficacy Power CCT K 3045 ± 175 3045 ± 175 CRI 100-point scale 90, R9 50 > 90, R9 > 50 0.7 > 0.7 Power factor Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design 3. Estimate efficiencies of the optical, thermal & electrical systems We used Cree’s Product Characterization Tool (PCT) tool to determine the drive currents for the design. We estimated 85% optical efficiency and 80% driver efficiency. We also estimated a solder‑point temperature (TSP) for each lamp as follows: 55 °C for the 20‑W equivalent MR16 lamp, 85 °C for the 35‑W equivalent MR16 lamp and 95 °C for the 50‑W equivalent MR16 lamp. The highlighted PCT data in Figure 1 shows the current levels at which the XLamp LEDs provide light output that exceeds the design goal for each lamp. 1 LED 1 $ Price SYS lm tot SYS lm/W 0.350 0.400 0.450 0.500 0.550 0.600 0.650 0.700 0.750 0.800 0.850 0.900 0.950 1.000 1.050 1.100 1.150 1.200 1.250 1.300 1.350 1.400 1.450 1.500 1.550 1.600 94.6 107.4 120 132.3 144.5 156.5 168.2 179.8 191.2 202.5 213.6 224.4 235.1 245.7 256.1 266.3 276.3 286.3 296 305.6 315 324.3 333.5 342.6 351.5 360.2 Flux LED 2 Model Cree XLamp XM-L2 {BWT} Current (A) Model T2 [200] 77.5 76.6 75.6 74.7 73.8 72.9 72 71.1 70.3 69.4 68.6 67.8 67 66.3 65.5 64.8 64.1 63.4 62.7 62 61.4 60.7 60.1 59.5 58.8 58.2 Tsp (ºC) LED Vf 2.79 2.8 2.82 2.83 2.85 2.86 2.88 2.89 2.9 2.92 2.93 2.94 2.95 2.97 2.98 2.99 3 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 Flux 55 LED W 0.976 1.122 1.269 1.417 1.567 1.718 1.87 2.023 2.177 2.333 2.49 2.647 2.806 2.965 3.126 3.287 3.45 3.613 3.777 3.942 4.107 4.274 4.441 4.609 4.778 4.948 E4 [635] $ Price SYS lm tot SYS lm/W 288.9 324.9 359.9 393.9 426.7 458.7 489.6 519.7 548.8 577 604.4 630.9 656.5 681.3 705.3 728.5 751 772.8 793.6 #N/A #N/A #N/A #N/A #N/A #N/A #N/A LED 3 Model Cree XLamp MK-R {EZW} 59 57.7 56.5 55.4 54.2 53.2 52.2 51.2 50.2 49.3 48.5 47.6 46.8 45.9 45.2 44.4 43.7 42.9 42.2 #N/A #N/A #N/A #N/A #N/A #N/A #N/A Tsp (ºC) LED Vf 11.19 11.26 11.32 11.39 11.44 11.5 11.55 11.6 11.65 11.7 11.74 11.78 11.82 11.86 11.9 11.93 11.97 12 12.03 #N/A #N/A #N/A #N/A #N/A #N/A #N/A 85 LED W 3.917 4.504 5.096 5.693 6.294 6.899 7.509 8.122 8.738 9.357 9.98 10.605 11.232 11.862 12.494 13.128 13.764 14.402 15.041 #N/A #N/A #N/A #N/A #N/A #N/A #N/A Flux Cree XLamp MT-G2: 6V {EZW} H0 [560] $ Price SYS lm tot SYS lm/W 156.4 178.2 199.6 220.7 241.6 262.2 282.4 302.4 322.1 341.6 360.8 379.7 398.4 416.8 434.9 452.9 470.5 488 505.2 522.2 539 555.5 571.9 588 603.8 619.7 67.2 66.7 66.1 65.5 64.9 64.3 63.7 63.1 62.5 61.9 61.3 60.7 60.2 59.6 59.1 58.6 58.1 57.6 57.1 56.6 56.1 55.6 55.2 54.7 54.3 53.9 Tsp (ºC) LED Vf 5.32 5.35 5.37 5.39 5.42 5.44 5.46 5.48 5.5 5.52 5.54 5.56 5.57 5.59 5.61 5.62 5.64 5.65 5.67 5.68 5.69 5.7 5.72 5.73 5.74 5.75 95 LED W 1.862 2.138 2.416 2.697 2.979 3.264 3.549 3.837 4.126 4.416 4.708 5.001 5.296 5.591 5.887 6.185 6.483 6.782 7.082 7.383 7.685 7.987 8.29 8.593 8.897 9.203 Figure 1: PCT view of drive current and lumen levels Thermal Requirements As is typical for Cree’s MR16 reference designs, the heat sink must be able to dissipate the necessary heat and serve as the mechanical housing for the other lamp components. We selected a commercially available aluminum heat sink that fits the compact MR16 form factor and used the heat sink for each lamp. The heat sink is part of a kit, shown in Figure 2, that also includes an optic holder and plastic base. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Figure 2: Heat sink/housing kit components Driver The driver for this MR16 lamp is located inside the lamp base. We used off‑the‑shelf constant‑current drivers, shown in Figure 3, that fit within the MR16 form factor. We modified the drivers by changing the current sense resistor(s) on each so the drivers operated as shown in Table 7. Table 7: Modified driver operating conditions MR16 Output Voltage (V) Output Current (A) XM-L2 20-W 3 1 MK-R 35-W 12 0.6 MT-G2 50-W 6 1.5 Figure 3: High‑CRI MR16 driver Secondary Optics We used a 30‑mm off‑the‑shelf total internal reflection (TIR) optic, shown in Figure 4, for each MR16 lamp. Figure 4: High-CRI MR16 optic 4. Calculate the number of LEDs The performance of the XLamp XM-L2, MK-R and MT-G2 LEDs enables the use of a single LED in MR16 lamps that better the light output of halogen lamps. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design 5. Consider all design possibilities Each XLamp LED used in this reference offers a wide range of color temperatures. Because an important goal of this reference design is excellent color rendering, in each case we selected an LED that offers a minimum CRI value of 90. 6. Complete the final steps: implementation and analysis Using the methodology described above, we determined a suitable combination of components and drive conditions to meet the design goals. This section describes how Cree assembled the MR16 lamps and shows the results of the design. Prototyping Details An animated view of the following steps can be seen at mtg.cree.com/#home. 1. We verified the component dimensions to ensure a correct fit. 2. Following the recommendations in the corresponding Cree Soldering and Handling Application Note4 for each XLamp LED, we reflow soldered each LED to a star board with an appropriate solder paste and reflow profile and cleaned the flux residue with isopropyl alcohol (IPA). 3. We soldered the LED wires to the star board. 4. We attached the star board to the heat sink using thermal tape. 5. We fed the LED input wires through the heat sink and soldered them to the driver. 6. We inserted the driver into the plastic base and attached the base to the heat sink with room temperature vulcanizing (RTV) silicone. 7. We attached the optic to the optic holder. 8. We snapped the optic holder and optic into place on the heat sink. 9. We performed final testing. Results Thermal Results Cree verified the board temperature with a thermocouple to confirm that the thermal dissipation performance of the heat sink is sufficient. Figure 5 shows the solder‑point temperature of each MR16 over time compared to the 23 °C ambient temperature. 4 Cree XLamp XM Family LED Soldering and Handling Application Note Cree XLamp MT & MK Family LED Soldering and Handling Application Note Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Figure 5: High-CRI MR16 thermal performance Based on the measured solder point temperatures, the junction temperatures (TJ) can be calculated as follows. TJ = TSP + (LED power * LED thermal resistance) Table 8 gives the TJ for each high‑CRI MR16 based on the measured TSP. Table 8: High‑CRI MR16 temperatures MR16 TSP (°C) LED Total Power (W) TJ (°C) XM-L2 20 W 54.6 3.0 62.1 MK-R 35 W 80.6 6.9 92.3 MT-G2 50 W 92.0 8.6 104.9 Optical and Electrical Results Cree’s testing of the high‑CRI MR16 lamps yielded the results in Table 9.5 As the table shows, each lamp exceeds its CBCP and light-output targets using approximately 77% of the energy of its equivalent halogen MR16 lamp. These energy savings produce a corresponding 77% cost savings, making these MR16 lamps much more economical to use than their halogen counterparts. The most important benefit of these MR16 lamps is the excellent color rendering each provides. 5 Testing was performed in a 2‑meter integrating sphere at Cree’s Santa Barbara Technology Center and in a type A goniometer at Cree’s Durham Technology Center. IES files for the MR16 lamps are available: XM-L2 20-W MR16, MK-R 35-W MR16, MT-G2 50-W MR16 Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Table 9: High‑CRI MR16 lamp steady-state results Characteristic Result Unit XM-L2 20-W MR16 MK-R 35-W MR16 MT-G2 50-W MR16 Light output lm 249 406 560 CBCP cd 1037 2287 2379 Beam angle Efficacy Power degrees 23 22 25 lm/W 55.7 50.1 49.5 W 4.5 8.1 11.3 CCT K 3113 3010 2989 CRI 100-point scale 92, R9 = 61 91, R9 = 61 91, R9 = 57 0.81 0.90 0.91 ENERGY STAR equivalency Power factor W 20 40 50 Estimated yearly energy cost - 3 hrs/day, $0.11/kWh $ 0.54 0.98 1.36 Figure 6, Figure 7 and Figure 8 show that the variation of chromaticity within the beam angle for each high-CRI MR16 lamp is within the ENERGY STAR limit. 0.0070 0.0060 0.0050 0.0040 Du'v' 0 degrees 90 degrees ENERGY STAR Limit 0.0030 0.0020 0.0010 0.0000 0 5 10 15 20 25 Beam Angle (°) Figure 6: XM-L2 high-CRI MR16 color spatial uniformity Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design 0.0070 0.0060 0.0050 0.0040 Du'v' 0 degrees 90 degrees ENERGY STAR Limit 0.0030 0.0020 0.0010 0.0000 0 5 10 15 20 Beam Angle (°) Figure 7: MK-R high-CRI MR16 color spatial uniformity 0.0070 0.0060 0.0050 0.0040 Du'v' 0 degrees 90 degrees ENERGY STAR Limit 0.0030 0.0020 0.0010 0.0000 0 5 10 15 20 25 Beam Angle (°) Figure 8: MT-G2 high-CRI MR16 color spatial uniformity We tested the intensity distribution of the three high-CRI MR16 lamps. Figure 9, Figure 10 and Figure 11 show an even intensity distribution for each lamp. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Figure 9: Polar candela distribution of XM-L2 high‑CRI MR16 lamp - 23° beam angle Figure 10: Polar candela distribution of MK-R high‑CRI MR16 lamp - 22° beam angle Figure 11: Polar candela distribution of MT-G2 high‑CRI MR16 lamp - 25° beam angle Table 10 shows the illuminance of the XM-L2 high-CRI MR16 lamp at various distances from the light source. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. 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 ® LED high‑CRI MR16 Reference Design Table 10: XM-L2 high‑CRI MR16 illuminance – 23° beam angle Height Center Beam Illuminance Beam Width 0.6 m 2.0 ft 283 fc 3,049 lx 0.2 m 0.7 ft 1.2 m 3.9 ft 71 fc 762 lx 0.5 m 1.6 ft 1.8 m 5.9 ft 31 fc 339 lx 0.7 m 2.3 ft 2.3 m 7.5 ft 18 fc 191 lx 1.0 m 3.3 ft 2.9 m 9.5 ft 11 fc 122 lx 1.2 m 3.9 ft 3.5 m 11.5 ft 8 fc 85 lx 1.5 m 4.9 ft Table 11shows the illuminance of the MK-R high-CRI MR16 lamp at various distances from the light source. Table 11: MK-R high‑CRI MR16 illuminance – 22° beam angle Height Center Beam Illuminance Beam Width 0.6 m 2.0 ft 624 fc 6,720 lx 0.2 m 0.7 ft 1.2 m 3.9 ft 156 fc 1,680 lx 0.4 m 1.3 ft 1.8 m 5.9 ft 69 fc 747 lx 0.7 m 2.3 ft 2.3 m 7.5 ft 39 fc 420 lx 0.9 m 3.0 ft 2.9 m 9.5 ft 25 fc 269 lx 1.1 m 3.6 ft 3.5 m 11.5 ft 17 fc 187 lx 1.3 m 4.3 ft Table 12 shows the illuminance of the MT-G2 high-CRI MR16 lamp at various distances from the light source. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 12 XLamp ® LED high‑CRI MR16 Reference Design Table 12: MT-G2 high‑CRI MR16 illuminance – 25° beam angle Height Center Beam Illuminance Beam Width 0.6 m 2.0 ft 650 fc 6,992 lx 0.3 m 1.0 ft 1.2 m 3.9 ft 162 fc 1,748 lx 0.5 m 1.6 ft 1.8 m 5.9 ft 72 fc 777 lx 0.8 m 2.0 ft 2.3 m 7.5 ft 41 fc 437 lx 1.0 m 3.3 ft 2.9 m 9.5 ft 26 fc 280 lx 1.3 m 4.3 ft 3.5 m 11.5 ft 18 fc 194 lx 1.5 m 4.9 ft Conclusion This reference design illustrates the excellent performance, in terms of both energy efficiency and color quality, of high‑CRI 20‑, 35- and 50‑W equivalent MR16 lamps based on the Cree XLamp XM-L2, MK-R and MT-G2 LEDs. The ability of these LEDs to provide 90-CRI minimum light output at ENERGY STAR light output levels demonstrates the possibility of using XLamp LED-based MR16 lamps in lighting applications that require excellent color rendering. An added benefit is the energy cost savings these lamps provide compared to their halogen equivalents. The lighting-class performance of these Cree XLamp LEDs makes them viable and attractive design options for high‑CRI LED-based MR16 lamps. Copyright © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 13 XLamp ® LED high‑CRI MR16 Reference Design Bill of materials Table 13: Bill of materials for high‑CRI MR16 lamps Component Company Texas Instruments Inc. Driver Heat sink/housing, optic holder, base Huizhou Taison Precision Parts Co., Ltd. Carclo Optics Order Code/ Model Number XM-L2 20-W MR16: LM3401 MK-R 35-W MR16: LM3444 MT-G2 50-W MR16: LM3401 www.ti.com/ www.ti.com/lit/ug/snvu112/snvu112.pdf www.ti.com/lit/ug/snvu123a/snvu123a.pdf www.ti.com/lit/ug/snvu112/snvu112.pdf MR16-HS-MTG-W1 www.hztaisun.com/productled_detail.aspx?t=mech&id=296 XM-L2 20-W MR16: 10757 MK-R 35-W MR16: 10756 Optic Web Link MT-G2 50-W MR16: 10756 www.carclo-optics.com/ www.carclo-optics.com/opticselect/intranet/optics/details/optics_pdf. php?id_optics=111 www.carclo-optics.com/opticselect/intranet/optics/details/optics_pdf. php?id_optics=110 www.carclo-optics.com/opticselect/intranet/optics/details/optics_pdf. php?id_optics=110 RTV silicone Dow Corning Corporation SE 9185 White www4.dowcorning.com/DataFiles/090007c8802d7bdc.pdf Star board t-Global Technology LP0001-01 www.tglobaltechnology.com/die-cut-datasheet/LP0001-01-Li2000A-02. pdf Thermal tape t-Global Technology Li-2000 www.tglobaltechnology.com/thermal-management-products/li-2000athermal-tape.php/ 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 © 2013-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree®, XLamp® and EasyWhite® are registered trademarks and the Cree logo is a trademark of Cree, Inc. ENERGY STAR® is a registered trademark of the U.S. Environmental Protection Agency. 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. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree Sales at [email protected]. 14