Cree XLamp LEDs Testing and Characterization

1 11 SUPPOrT DOCUMeNTCopyright 2011-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree and XLamp are registered trademarks and the Cree logo is a trademark of Cree, Inc. This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at For warranty information, please contact Cree Sales at Silicon DriveDurham, NC 27703 USA Tel: + AP81 rev 1 DCree XLamp LEDsTesting and CharacterizationInTroDuCTIonThis document is a tutorial on Cree s LeD test conditions and shows how differences in test conditions can lead to measurement discrepancies between Cree s results and those of our may ask Cree, What did you send to me?

2 When customer LED or luminaire Testing finds that LED luminous flux or color point are different than expected. The time and resources needed to resolve such a situation increases development samples from Cree can help alleviate this situation and remove this unnecessary delay in customers development of ConTEnTsIntroduction ..1 Flux and chromaticity ..2 XLamp LeD test conditions ..3 Measurement discrepancies ..6To avoid discrepancies ..622 Copyright 2011-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice.

3 Cree and XLamp are registered trademarks and the Cree logo is a trademark of Cree, Inc. This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at For warranty information, please contact Cree Sales at LeD Testing & CHArACTerIZATIONfLuX anD ChromaTICITyCree XLamp LEDs are provided in specific luminous flux ranges and defined color regions as shown in the examples in Table 1 and Figure 1. These luminous flux ranges and color regions, known in the LED industry as bins, can be found on the Cree website ( ) in the Binning and Labeling documents for each of the XLamp LeD product 1: Cree XP family luminous flux ranges or binsGroup CodeMin.

4 Luminous FluxMax. Luminous 2011-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree and XLamp are registered trademarks and the Cree logo is a trademark of Cree, Inc. This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at For warranty information, please contact Cree Sales at LeD Testing & Characterization figure 1: Chromaticity regions or bins for Cree XP family XLamp LEDsXLamP LED TEsT ConDITIonsDuring XLamp LeD Testing in its manufacturing facilities, Cree measures the photometric properties of each LeD and sorts the LeDs into the appropriate chromaticity and flux bins.

5 Cree calibrates its production test systems worldwide to United States National Institute of Standards and Technology (NIST) standards and performs production Testing under specific and exacting conditions. During Testing , LEDs have historically been operated at a drive current of 350 mA and a nominal ambient temperature of 25 C. The actual measurement time of the light emitted by the LED, known as the integration time, is 25 msec. Because the integration time is so short, the LED junction temperature does not exceed the 25 C ambient temperature. Beginning in 2011, Cree started binning select products at a higher temperature, 85 C.

6 This hot binning process helps customers reduce development cost by simulating LED operating Testing , the LeDs are placed into carrier tape on a reel and shipped to the customer. All the LeDs on a single reel are from a single flux bin and chromaticity bin that is part of the kit the customer has LeDs are operated at drive currents or temperatures that are not equal to the test current or test temperature, the resulting photometric data may not match that of the specific ordered bin. This is due to the well known fact that both temperature and drive current affect LED light output. Graphs in Figures 2 and 3 show the effects of temperature and drive current on luminous flux.

7 Data sheets on the Cree website make these graphs available for each LeD K3000 K3500 K4000 K4500 K5000 K3A3B3C3D4A4B4C4D5A15A25A35A45B15B25B35B 45C15C 25C 35C 45D15D25D35D46A16A 26A36A46B16B26B36B46C16C26C36C46D16D26D3 6D47A17A27A37A47B17B27B37B47C 17C 27C 37C 47D17D27D37D48A18A 28A38A 48B18B28B38B48C18C28C38C 77A44 Copyright 2011-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree and XLamp are registered trademarks and the Cree logo is a trademark of Cree, Inc. This document is provided for informational purposes only and is not a warranty or a specification.

8 For product specifications, please see the data sheets available at For warranty information, please contact Cree Sales at LeD Testing & Characterization figure 2: Cree XLamp XP-G LED luminous flux vs. forward forward current used during XP-G Testing is 350 mA (100% LF).Figure 3: Cree XLamp XP-G LED luminous flux vs. junction junction temperature during XP-G Testing is 25 C (100% LF).In much the same way that luminous flux is affected by drive current and temperature, it is well known that chromaticity is also affected by drive current and temperature. Figures 4 and 5 show the typical color shift of the warm white XP-e LeD as drive current and temperature Luminous FluxJunction Temperature ( C)55 Copyright 2011-2016 Cree, Inc.

9 All rights reserved. The information in this document is subject to change without notice. Cree and XLamp are registered trademarks and the Cree logo is a trademark of Cree, Inc. This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at For warranty information, please contact Cree Sales at LeD Testing & CHArACTerIZATIONC urrent (mA)1502003003505007001000 CCT-10-6-1---5913figure 4: Color shift vs. drive current for 3000 K warm white XP-E LEDTsp ( C)255080100 CCT----14-18-8 Figure 5: Color shift vs.

10 Temperature for 3000 K warm white XP-E LED CCy CCxXP-E WWANSI 3000 K3000 K150 mA350 mA1000 mA CCy CCxXP-E WWANSI 3000 K3000 K25 C100 C66 Copyright 2011-2016 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree and XLamp are registered trademarks and the Cree logo is a trademark of Cree, Inc. This document is provided for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at For warranty information, please contact Cree Sales at LeD Testing & CHArACTerIZATIONmEasurEmEnT DIsCrEPanCIEsUpon measuring individual LEDs or assembled lighting products, Cree XLamp LED customers occasionally find that the luminous flux does not meet their expectations or that the color point is not in the expected bin.