Ssl Training December 2009 [Compatibility Mode]

Solid State Lighting
Seminar

December 2009

Agenda

• Cree Background
• SSL/LED Basics
– Packages, Benefits, Light source comparisons
– Binning, Lifetime, Reliability, Standards, Safety
• Cree LED Components Portfolio
• Target Markets
• LED Design Considerations
– Optics, Thermals, Electrical (with examples)
– Quality, Thinking ahead
• LED Roadmaps
• Cree Support

Copyright © 2009 Cree, Inc. pg. 2

Presenters

Vince Feorenzo
Vice President
Americas Sales
Cree LED Components, RF

Steve Druckenmiller
Field Applications Engineer
Americas East
Cree LED Components, RF


Cree Background


Cree, Inc. Snapshot

LED Technology Leader
• Leading supplier of InGaN LED chips
• Created the first Lighting Class LEDs
• U.S. Patents: 827
• Foreign Patents: 1,800

Global Scale
• Locations: 12
• Employees: 3,200
• Headquarters: Durham NC, USA

Company Facts
• Revenue: $567.3 million (FY 2009)
• NASDAQ: CREE


Cree Global Footprint

• Headquarters:
– Durham, NC, USA
• Global Locations:
– Dulles, VA, USA
– Hong Kong
– Huizhou, China
– Munich, Germany
– Penang, Malaysia
– Taipei, Taiwan
– Tokyo, Japan
– Santa Barbara, CA
– Seoul, Korea
– Shanghai, China
– Shenzhen, China

Chip Packaging
R&D Design Center
Manufacturing Manufacturing


Cree - Leading the LED Lighting Revolution

2002
Introduced 2008
1st XBright® LED Demonstrated record
power chip 161 lumens/Watt
1989 from LED component
2006
Commercialized First “Lighting-Class”
the first blue LED LED components

1995
2009
Blue LEDs
2004 Launched LED
1987 designed
PAR38 Lamp
Cree founded into VW First XLamp
with unrivaled color and
LEDs brought
to market
2007 efficacy
1st commercially-viable
LED downlight
introduced (LR6)


Cree Businesses

Cree
SiC/GaN
Materials


Cree LED Lighting Strategy

Market Opportunity
LED Lighting
LED Lighting
• Lead the market &
accelerate adoption
LED Components • Create demand/pull for
LED lighting

LED Components
• Drive Revenue
• Enable the market with
LED Chips “lighting-class” LEDs

LED Chips
Materials
• Technology to enable
components

SSL/LED Basics


LED: Theory of Operation

• LEDs consist of several layers of
semiconductor material
• Light is generated in the PN
junction when a current is applied
• LED light is monochromatic; the
color depends on the materials
used and layer thickness
• There are two material systems
(AlInGaP and InGaN) used to
produce LEDs in all colors from blue
to red


Typical High-Power LED Package
Substrate/Lead
Lens (glass,
Frame silicone)

Encapsulant

Wire bond
Reflector

ESD protection LED chip Phosphor
5mm
Type
• The LED Package provides:
– Protection for the LED chip from the outside environment
– Conductive path to carry generated heat away from the LED chip
– Lens & encapsulant systems to shape and direct the chip flux

• LED Chip: Determines raw brightness and efficacy
• Phosphor: Convert blue light to white. Determines white
color point and stability.

Typical LED Characteristics

• Thermal Resistance:
Increase in junction
temperature (TJ)
above the solder point
in °C for every Watt of
electrical energy
Beam Angle • Viewing Angle:
Commonly depicted
as full-width, half-
maximum (FWHM)

°
Important Note: All LED data is for 20ms pulse, 25°C


• Temperature Coefficient
of voltage:
Describes the dependency of • ESD Protection
Forward Voltage (VF) on the Every LED has integral diode for
junction temperature (TJ) Electrostatic Discharge (ESD)
– The good news: This makes protection, in accordance with
VF slightly lower at higher Human Body Model = 2kV
temperatures

* Common to both warm and cool white LEDs



• DC Pulse Current: • DC Forward Current:
Maximum DC current the (Max IF) is the maximum
LED can safely and forward current the LED can
reliably withstand for safely and reliably withstand.
short pulse duration Warm white LEDs are often
rated lower on Max IF vs. cool
white due to phosphor stability

* Common to both warm and cool white LEDs



• LED Junction Temperature (TJ)
The maximum temperature the LED
junction (light-generating part of
the LED chip) can safely and
reliably withstand before failure

• Forward Voltage:
The voltage for a given
constant current, IF.
Typical and max shown


• Correlated Color Temperature (CCT):
Spectral bandwidth of white LEDs,
defined as color temperature and x,y
coordinates

• Dominant Wavelength (DWL):
Monochromatic wavelength of
color LEDs



• Luminous Flux (LF):
You will normally
specify a specific LF bin
from your supplier
– LF for Lighting-class
LEDs are generally
rated for 350mA IF
– LF is calculated for
higher drive currents
– Brighter bins
generally cost more
– Warm white LEDs
are generally about
25% lower LF than
cool white for a
given IF


Traditional Lighting Technologies

Incandescent Fluorescent Compact Fluorescent

• Inexpensive
• Very inexpensive • Efficient • Energy efficient
• Great color • Contains mercury • Contains mercury
• Very short lifetime • Difficult to dim/control • High price vs. incand.
• Extremely inefficient • Problems in cold temps • Problems in cold temps

Halogen High Intensity Discharge

• Great color • Inexpensive
• Focused light • Efficient
• Very short lifetime • Long start time
• Inefficient • Poor color

Basic Advantages of LED Light

• LEDs are…very energy efficient >100LPW
(near-term roadmap to >150LPW…)
• Are directional No wasted light, any
pattern possible
• Have very long lifetime >50,000 hours to
70% Lumen Maintenance (L70)
• Are inherently rugged No filament to
break
• Start instantly nanoseconds vs. > 10 min
re-strike (HID)
• Are environmentally sound no Hg, Pb,
heavy metals
• Are infinitely dimmable, controllable New
lighting features, power savings
• Love cold temperatures No cold starting
issues

Light Source Comparison

Data Sheet Usable* Lifetime
Light Type CRI
lm/W lm/W (hrs)
Incandescent 13-16 <15 3k 100
Halogen 20 12-20 6k 100
T12 fluorescent 60 40-50 20k 62-85
Metal halide 65-70 35-40 10k-20k 60-90
High-Power LED (Warm White) 80 55-65 50k+ 80-85
T5 fluorescent 90 75-85 30k 85
T8 fluorescent 90+ 80-90 30-40k 78-85
High-pressure sodium 95-110 55-65 24k 22
Low-pressure sodium 120-140 65-75 16k <5
High-Power LED (Cool White) 132 >100 50k+ 75

But source comparisons can be misleading. More to come …
* Typical expected performance in real-life applications. Based on mean lumens, and including
ballast/driver, thermal equilibrium and typical fixture Coefficient of Utilization losses.


Binning - Two Main Types

• Chromaticity or Color Binning
– Some defined “Box” in the
white area on or near the
Black Body Locus (White LEDs)
– Dominant Wavelength (Color
LEDs)

• Brightness or Flux Binning
– Minimum luminous flux or
radiant Flux

– Bin sizes (flux range)
varies by supplier


Luminous Flux Binning

• LEDs are tested & sorted into luminous flux bins
• Bins are grouped into guaranteed minimum flux
levels at a given drive (test) current

Flux:
73.9 lm

Driver
350 mA


1931 CIE Chromaticity Diagram

The 1931 CIE chromaticity scale
gives everyone a common
framework to reference very
specific shades of color

White LED lamps are binned and
sold based on the shade of white
color represented on a
Warm chromaticity scale in terms of x, y
coordinates and color
temperature

Cool
How It Works
• Monochromatic (direct) colors are on the
outside edge of the diagram
• All combinations of colors are on the
inside, with white colors in the middle


Correlated Color Temperature (CCT)

• Not all “white” light lies directly on the BBL
• CCT refers to the Plankian black-body radiator color temperature (CT)
that is closest to the color of the white light source (in Kelvin)

Relationship between CCT & CT Examples of CCTs


Blue (or UV) + Phosphor = White

• White LED light is generally made
from a blue LED matched with a
yellow phosphor
Yellow
Phosphor
• Adding more red phosphor
pushes the color temperature
White Light closer to the “warm” white CCT
points…less, more to the blue
(“cool” white)
• The human eye is extraordinarily
sensitive, so small process
variations in chip wavelength;
phosphor thickness,
Blue LED
concentration, composition;
and/or deposition conditions
make a big difference


MacAdam Ellipses
• David MacAdam – a scientist at Kodak - performed the
research in the late 1940’s with the goal of determining a
series of boundaries around several color targets (x, y
coordinates) illustrating how much one can “ stray” from the
target before perceiving a difference from that target color
• MacAdam found that these color
regions took the form of an ellipse
on the CIE 1931 chromaticity chart
• A MacAdam Ellipse is defined as
being the region on the CIE
chromaticity chart in which the y
variations in color in that region
are indistinguishable from the
color of the point at the center
of the ellipse x


MacAdam Ellipses (10X)

Note: The size and
orientation of the ellipse
varies significantly
with it’s location in the
CIE color space


MacAdam Ellipse Steps

1-step: One standard deviation (68.3%) of population perceives a color difference

2-step: Two standard deviation (97.5%) of population perceives a color difference

3-step: Three standard deviation (99.7%) of population perceives a color difference

One Step
Two Step

Three Step


MacAdams In the “Real” World

MacAdam Ellipse defines the chromaticity bin size
0.45
2700 K
0.44
3000 K
0.43
3500 K
0.42
0.41 4000 K + BBL
+
0.40
4500 K +
0.39
CCy

0.38 5000 K +
0.37 5700 K +
0.36
6500 K +
0.35
0.34
+
0.33 +
0.32
0.31
0.30 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.40 0.41 0.42 0.43 0.44 0.45 0.46 0.47 0.48 0.49 0.50

CCx
ANSI CFL Standard (7-steps)
ANSI C78.377A SSL Chromaticity Standard


Cree High-Power LED Chromaticity Binning

0.46
0.45 2700K
3000K
0.44
CCy: 0.35 0.43 3500K
CCx: 0.32 0.42 4000K
0.41 4500K

0.40
5000K
0.39
0.38 5700K

0.37
CCy

6500K
0.36 ANSI
C78.377A
0.35
8000K
0.34
Driver 0.33
350 mA 0.32
0.31
0.30
0.29
0.28
0.28

0.29

0.30

0.31

0.32

0.33

0.34

0.35

0.36

0.37

0.38

0.39

0.40

0.41

0.42

0.43

0.44

0.45

0.46

0.47

0.48

0.49
CCx


Cree High-Power LED Chromaticity Binning

Bin quadrangles (corners) are defined by four x,y pairs.


Cree Kits (Order) codes vs. Bins

Kit code, aka Order code: used to describe a group of chromaticity
and flux bins that are acceptable to fulfill an order.


Color Rendering Index System

• Based on color
comparison of 14
sample tiles with
unsaturated colors
• Incandescent bulbs
have CRI 100
3 10 (<5000K CT)
14
3000 2500
11
4
4000 2
• Sunlight is CRI 100
6000 13
1
(> 5000K CT)
5 D65
9
8
• LEDs (esp. RGB)
6 7
have fully saturated
12
colors and actually
pay a mathematical
penalty in the CRI
system


CRI & CQS of Selected Light Sources

Source CRI
Low Pressure Sodium <5
High Pressure Sodium 20 1 2 3 4
RGB LED (typical) 31
Mercury Vapor 43
Cool White Fluorescent 63 5 6 7 8
Metal halide 64
Cool White LED 70
Daylight Fluorescent 76
Warm White LED (YAG) 81
9 10 11 12
Tri-phosphor Fluorescent 82
F32T8 Tri-phosphor 85
BSY + R LED 93 13 14
Halogen MR16 99
Incandescent 100


Color Rendering/Color Quality In Real Life

CRI = 62 CRI = 93


LED Reliability, Lumen Maintenance


LED Reliability Testing

• LEDs are semiconductor components that
happen to emit light
• Most LED manufacturers conduct the traditional
standardized semiconductor component reliability testing on
their LEDs (http://www.cree.com/products/pdf/XLamp_Reliability.pdf)
• Test methods vary among suppliers. Get the data!


Power LED White Point Stability Over Time

• All power LED suppliers use different phosphor process, so
color shift will vary. Get the test data!
• Low power LEDs will be different also (usually shift more).
Warm White XR-E Chromaticity Shifting
during 85C High Temp Operating Life Test
0.010
If = 700mA
0.008

0.006

0.004

0.002
v'

0.000
-0.010 -0.008 -0.006 -0.004 -0.002 0.000 0.002 0.004 0.006 0.008 0.010

-0.002

-0.004

-0.006 1008 hours
3145 hours
-0.008 4507 hours
5087 hours
-0.010 4-step Macadam
u' 7-step Macadam


LED Lifetime vs Lumen Maintenance
110%

100%

90%
Lumen Output (%)

100 W Incandescent
5mm LED
80% 42W CFL
50 W Tungsten Halide
70% 400 W Metal Halide
25 W T8 Fluorescent
Lighting-class LED
60%

50%

40%
0 10 20 30 40 50 60 70 80 90 100
Operating Time (k hrs)
Courtesy LRC, Rensellaer Polytechnic Institute

• Lighting-class LEDs become dimmer over time
with no catastrophic failure
• End of life defined by the LED becoming too dim
– needed to define Lumen Maintenance (L70)
• Not all LED types have a long L70 or lifetime


Lumen Maintenance Definition

Definition: change in light output of a light source over operational
life, relative to initially measured light output
Lxx = time to xx% of original light output
• L70 = time to 70% of original light output
• L50 = time to 50% of original light output
How many hours until L70 is reached for LEDs? 50000 or longer?

Lumen Maintenance: Hypothetical HID Lamp Traditional light
110%
sources gradually
100% dim then fail
catastrophically
Lumen Output (%)

90% (“burn out”)
80%

70% L70 = 10,000 hours
60%

50%

40%
0 5 10 15 20 25
Operating Time (k hrs)


40,000 Hour / 4.5 Year XLamp Long-Term Data

• Low temp (25ºC) testing is a good surrogate for
At lower ambient air temperature, LEDs hardly depreciate at all.
the LED chip depreciation – 1-2% @ TJ = 65ºC


Predicting L70
• Widely adopted ASSIST method and exponential curve fitting
• L70 is extrapolated from real measurement data
• Is this accurate? Do all supplier’s LEDs degrade the same?

Measured Data


LED Lumen Maintenance Standards

• The Illumination Engineering Society of North America
published IES LM-80-2008 12 months ago to characterize
the Lumen Maintenance aspect of LED semiconductor
components
– For fixture companies to obtain Energy Star approval rating
– Helps define a standard test method between all LED suppliers

• Note: Lumen Maintenance ≠ LED Lifetime. The IESNA SSL
sub-committee (TM-21) is now working to develop an
accurate algorithm for modeling long term LED behavior


LED Test Configuration Per IES LM-80-2008

• During test, the temperature of the solder pad of the lamps and
the air around the lamps is the same
• Per LM-80,
− For 55ºC testing, the TSP of the lamps and air are both at 55ºC
− For 85ºC testing, the TSP of the lamps and air are both at 85ºC

Temperature of ambient around lamps is actively
controlled by air flowing through chamber

Lamps are mounted to MCPCB’s.

Temperature of solder pad of lamps is independently actively
controlled by fluid flowing through heat sink.


LED Lumen Maintenance Critical Parameters

1. TAIR
Ambient Air Temperature

2. TJ
Junction Temperature

3. TSP / TC / TS
Solder-Point Temperature /
Case Temperature

4. IF
Forward Current /
Drive Current


High Air Temperature Degrades Encapsulant

• Cree now understands that the silicone-based encapsulants
used in the industry degrade when exposed to high
temperatures
• Degradation comes from organic pendant groups (e.g. CH3,
C6H5, -OH) that can off-gas or be trapped in the matrix
• The higher the air temperature, the more the encapsulant
will degrade, the more light lost


Encapsulants Degrade Even Without Lighting the LED

• The out-diffusion of volatiles from silicone may be
causing the refractive index of encapsulant to decrease
• As the refractive index decreases the critical angle
increases allowing less light to be emitted from the chip


Cree Power LED Lifetime Model - TM21 Consideration

• Degradation in first 5,000 hours is mostly due to degradation in
the silicone encapsulant
• After 5,000 hours, this mechanism drops out and the slower chip
degradation dominates
• We see no early life failures in our XLamp systems

L70 Lifetime Prediction – TAIR = 35ºC


L70 Lifetime Prediction – IF = 350 mA


LED Lumen Maintenance Summary

• Cree has accumulated millions of XLamp XR-E LED lamp
device hours of long-term data under both LM-80-compliant
conditions and other test configurations

• The effects of TAIR, TJ, TSP and IF on long-term lumen
maintenance have been closely studied and are understood

• Cree has observed that the lumen maintenance
characteristics of the XLamp XR-E white LED lamps are
different in the first 5,000 hours (called Period A) than in the
time period following 5,000 hours (called Period B)

• A “best fit” algorithm was developed to accurately model
this behavior, based on critical parameters TAIR, TJ, TSP and IF

• This algorithm is likely to be different for every LED lamp
system (e.g. XLamp XP, MC, Rebel, Dragon, NS6, etc…)

• L70 Lifetime Prediction ≠ LM-80


LED Eye Safety Standards and Regulations

IEC/EN 60825-1: Safety of laser products

• All Cree LED packaging still references this standard

1. The scope of IEC 60825-1 is limited to the end system, not the
component. This makes sense because our customers can add
optics that can either increase or decrease the eye safety risk of
LEDs.

2. IEC removed LEDs from the scope of IEC 60825-1, so this standard
no longer applies to LEDs. (Replaced by IEC 62471)

3. We have tested bare XLamp LEDs under IEC 60825-1 and all of
them are rated as Class 2. We have the test report available.


LED Eye Safety Standards and Regulations

IEC 62471: Photobiological safety of lamps and lamp systems

• How to evaluate photobiological safety of lamps and luminaires
– Requires the lamp manufacturer (i.e., Cree) to evaluate the risk group of the
lamp itself
– ALSO requires the entire luminaire to be tested

• Provides no guidance on how to label products

• Classifications are:
– Exempt
– RG-1 (Low Risk)
– RG-2 (Moderate Risk)
– RG-3 (High Risk)


LED Eye Safety Labeling Requirements

United States
IESNA/ANSI RP-27.3-07: Recommended Practice for Photobiological
Safety for Lamps - Risk Group Classification and Labeling

• Requires small changes to packaging & data sheet information
• Also requires absolute spectral power data to be available on
request
– Eye Safety application note coming soon to provide this “on request” data in one
place online & explain relevant standards

EU
• Currently most states may use IEC 62031:2008 LED Modules for
General Lighting – Safety Specifications
• Our understanding is that EU is moving to adopt IEC 62471 in its
place
• Labeling standard may be coming soon and may require another
change to labels / data sheets separate from ANSI RP-27


SSL Standards Status
Status of ANSI, IESNA, and CIE Solid State Lighting Standards (Partial List)
Comment Projected
Standard Draft Comment
Resolution Publication
IESNA RP-16
X X X Complete
Definitions
ANSI BSR C78.377A,
X X X Complete
Chromaticity
IESNA LM 79,
X X X Complete
Luminous Flux
IESNA LM 80,
X X X Complete
Lumen Depreciation
NEMA SSL-1,
X
SSL Drivers
NEMA LSD-44 & 45, (SSL-2)
X X
SSL Interconnect
NEMA SSL-3,
X
LED Binning
TM-21,
X
Lumen Maintenance Extrapolation Method
NEMA-ALA Joint White Paper
X
Definition of Functional & Decorative Lighting
IESNA LM-xx,
X
LED Light Engine & Lamp Measurement
CIE S009,
X X
Photobiological Safety


List of SSL Standards In Progress (4/2009)

• Additional primary standards identified or underway
– CIE TC1-69 Color Quality Scale (new CRI type metric)
– C82.SSL1 LED Drivers
– UL 8750 Safety
– TM-21 Lumen Maintenance Extrapolation Method
– LM-XX1 Methods for the Measurements of High Power LEDs
– LM-XX2 LED “Light Engine” Measurements (PIF for approval)
– LM-XX2 Photometric Testing of Outdoor LED Luminaires (based on LM-10/31)
– RP-16 Additional LED Definitions
– C78.SSL2 LED Sub-assembly Interfaces
– C78.SSL3 Binning Standards
– C78.SSL4 Form Factors
– ANSI SSL2 LSD-45 Sockets & Interconnects Consistency Standard
– ANSI C82.4 Driver Performance Standard
– CIE TC2-46 CIE/ISO LED Intensity Measurements
– CIE TC2-50 Optical Properties of LED Arrays
– CIE TC2-58 Luminance and Radiance of LEDs
– IEEE P1789 – Recommended Practices of Modulating Current in High Brightness
LEDs for Mitigating Health Risks to Viewers
– IEC SC 34A – Performance Standard for LED Lamps
– IEC SC 34A 62031:2008 LED Modules – Safety
– IEC SC 34C 61347-2-13:2006 – Lamp Controlgear – Part 2-13: DC or AC Controlgear for LED Modules
– IEC SC 34A IEC 62560 Self-Ballasted LED Lamps
– IEC SC 34A <tbd> LED Lamps > 50 V – Safety Specs

• Cree XLamps XPE Power LEDs are UL Recognized
– Pass UL8750 proposed safety testing


Cree LED Components


High-Bright LED Product Families

P4

P2 Round

Screen Master
P2 Oval PLCC/SMD


P2 Round – 5mm

• Single Color Signs:
– C503 series has been the most popular
• Available in Red, Green, Blue, Amber, & White

– Amber/Red have found success in transportation and roadway
signs
° °
• New min 15° & 30° amber will be coming out soon targeted
towards the transportation market

– Typical applications for White include:
• C503 = °
15° Torch/Flashlight
• C512 = °
25° Torch/Flashlight – Garden Light
• C513 = °
55° Advertisement Boxes
• C543 = °
20° Garden Light
• C534 = 140°° Garden Light
• C535 = 110°° Garden Light


P2 Oval – 4mm & 5mm

• Full Color Video Screens:
– C4SMF-RJS, C4SMF-GJS, C4SMF-BJS
– C4SMG-RJS, C4SMG-GJS,C4SMG-BJS
• The Right LED for the right application

– C5SM
• Available in R/G/B/Amber
• Different brightness family available
° °
• 110°x40° viewing angle

– ScreenMaster family has a matched RGB far field pattern

– C566 series
• Red/Amber for monochrome displays
° °


Product Family – P4

• CP41 series
– Round lens
• Normal Lambertian pattern
– Available in R/G/B/A/W
– Various Viewing Angles

• CP42 series
– Concave lens
• Batwing radiation pattern
– Available in R/G/A

• CP43 series
– Oval lens
° °
– Available in Red/Amber

pg. 62

Copyright © 2009, Cree, Inc.

Product Family – PLCC families (Full Color)

• CLP6C-FKB 6050 (6mm x 5.5mm) package
– R(560-1120mcd), G(1120-2240mcd) & B(280-560mcd)

• CLP6S-FKW 6050 (6mm x 5.5mm) package
– R(710-1800mcd), G(710-1800mcd) & B(280-710mcd)

• CLV1A-FKW 3228 (3.2mm x 2.8mm) package
– R(355-900mcd), G(560-1400mcd) & B(180-450mcd)

• CLPPA 3228 (3.2mm x 2.8mm) package
– R(180-450mcd), G(280-710mcd) & B(71-180mcd)

• CLV6A-FKB (5.5mm x 5.5mm) package
– First SMT LED with IPx5 rating
– Water resistant
– No polycarbonate cover needed for outdoor color display


Product Family – PLCC families (Single Color)

• CLP6C 6050 (6mm x 5.5mm) • PLCC4:
– Red(3550-7100mcd)
– CLM2B °
with lens (60° VA)
– Amber(3550-9000mcd)
• Red (2240-5600mcd)
• Amber (3550-9000mcd)
• CLM6S 3533 (3.5mm x 3.3mm) – CLM2T °
with lens (60° VA)
– Green(1120-2800mcd)
• Amber (1120-2800mcd)
– Blue(355-900mcd)
• CLM6T 3533 (3.5mm x 3.3mm)
– Red (710-1800mcd)

• CLM4B 3227 (3.2mm x 2.7mm)
– -AKB: Amber(1120-2800mcd) (black
• PLCC2:
face) – CLM3C 2720 (2.7mm x 2.0mm)
– -GKW: Green(1400-3550mcd)
• Red (560-1400mcd)
– -BKW: Blue(355-900mcd)
– -PKW: Orange(1120-2800mcd) • Amber (355-900mcd)
– RKW: Red(1120-2800mcd) – CLM3S 2720 (2.7mm x 2.0mm)
– -AKW: Amber(1120-2800mcd)
• Blue(112-355mcd)


Product Family – PLCC families (Single Color)

• CLM4S-DKB 3228 (3.2mm x 2.8mm) package
– Red(140-355mcd) & Green(280-900mcd)

• CLM4S-DKW 3228 (3.2mm x 2.8mm) package
– Red(140-355mcd) & Green(280-900mcd)

• CLM4TS-RDK 3227 (3.2mm x 2.7mm) package
– Red(560-1400mcd)

• CLM1B 3227 (3.2mm x 2.7mm) package
– Blue(280-710mcd) & Green(710-2240mcd)
– Red(450-1120mcd) & Amber(355-900mcd)
• CLM1S 3227 (3.2mm x 2.7mm) package
– Blue(112-355mcd) & Green(355-1120mcd)
• CLM1T 3227 (3.2mm x 2.7mm) package
– Red(280-560mcd)


Product Family – PLCC families (White)

• CLN6A 5050 Package (5mm x 5mm) • CLM3C 2720 (2.7mm x 2.0mm) package
– CW = 60.5-101.8 lm • CW = 1,400-3,550mcd
– WW = 51-101.8 lm • WW = 1,120-2,800mcd
• CLM3A 2720 (2.7mm x 2.0mm) package
• CLP6B 6050 (6mm x 5.5mm) package • Cool White = 1,120-2,240mcd

– CW = 7,100-18,000mcd • CLM3S 2720 (2.7mm x 2.0mm) package
– WW = 7,100-14,000mcd • CW = 355-1,120mcd
• CLP6S 6050 (6mm x 5.5mm) package
– CW = 3,550-7,100mcd / WW = 2,800-
7,100mcd

• CLA1A no lens, 3228 (3.2mm x 2.8mm)
package • CLM1C 3227 (3.2mm x 2.7mm) package
– CW = 1,800-4,500mcd • CW = 710-1,800mcd
– WW = 1,400-3,550mcd • CLM1S 3227 (3.2mm x 2.7mm) package
• CLA2A 2 die, 3228 (3.2mm x 2.8mm)
• WW = 355-1,120mcd
package
– CW = 2,240-5,600mcd


HB – Smart Part Numbering System
Single Color: CAAAB-DEG-ZHHKKMNT
RGB: CAAAB-DEG-ZHhJjKkLlMmT


Which HB LED to use (and where)?

• Why use Round LEDs? • Why Use Oval LEDs?
– Mostly used in Single – Full Color Video Displays
color signs – Wider viewing angle
– Variety of viewing angles ° ° °
• 110°x45°, 70°x35° °
° ° ° ° °
(15°, 23°, 30°, 50°, >70°) – Screen master series has a
– Available in R/G/B/A/W matched RGB field pattern
– 3mm & 5mm available – 4mm & 5mm available

• P4 LEDs – • SMD / PLCC package
– Used more for Channel Letters – SMD 3-in-1 for Full Color Video
and Automotive and – White PLCC for linear lighting
Advertising Boxes & light bulb applications
– Different lenses for various – New IPx5 rated (outdoor)
radiation patterns – Black Face & White face/body
– PLCC2/4/6


High-Power XLamp LED Product Families


What are Lighting-Class LEDs?

• 120+ LPW
Flux & • Energy Savings
Efficacy • Small source size
Only
(direct light where
Lighting-Class needed)

LEDs have the light output,
• ANSI chromaticity
efficacy, quality of light bins & sub-bins
and reliability to replace
Quality • Consistent reels of
traditional lighting sources
of Light LEDs
• High standard CRI
• Color point stability

• Energy Star approved
lumen maintenance
Reliability • Lifetime prediction
• Maintenance
Avoidance


Cree XLamp LED Product Portfolio – White

Single Die Multiple Die
XLamp
XR-C XR-E XP-C XP-E XP-G MC-E MX-6
Footprint
7.0 x 9.0 3.45 x 3.45 7.0 x 9.0 6.5 x 5.0
(mm)
Max Up to 700 mA
500 mA 500 mA 700 mA 1000 mA 350 mA
Current 1000 mA (per LED)

Viewing
90° 90° 110° 115° 125° 110° 120°
Angle

LM-80 accepted LM-80 accepted LM-80 accepted


XLamp XR-E & XR-C White

• Long history of LED innovation and reliability:
2006 First lighting-class cool white LED
2007 First lighting-class warm white LED
First LED offered in ANSI C78.377A chromaticity bins
First 100 lumen cool white LED to ship in volume
2009 Approved as DOE Energy Star SSL compliant for lumen maintenance

• Tens of millions of LEDs shipping per quarter
• Lighting up LED industry’s most high-profile installations


XLamp XP-E & XP-C White

• Small footprint device
• Symmetric design offers matching mechanical and
optical center
– Improves optical efficiency
– More efficient secondary optics
– Easier manufacturing


XLamp XP-E White Characteristics & Features

Cool White Neutral White Warm White
CCT (K) 10,000K – 5,000K 5,000K – 3,700K 3,700K – 2,600K

Viewing Angle 115º 115º 115º

Thermal Resistance (ºC/W) 9 9 9

Max Current (mA) 700 700 700

Typical Vf @ 350 mA (V) 3.2 3.2 3.2

Features
• ANSI-compatible chromaticity bins
• Accepted by U.S. DOE for ENERGY STAR lumen maintenance
• Electrically neutral thermal path
• High maximum LED junction temperature: 150ºC
• Unlimited floor life at ≤30ºC / 85% RH
• Reflow solderable JEDEC J-STD-020C compatible
• RoHS and REACH-compliant
• UL-recognized component (E326295)


XLamp XP-C White Characteristics & Features

CCT (K) 10,000K – 5,000K 5,000K – 3,700K 3,700K – 2,600K



Max Current (mA) 500 500 500

Typical Vf @ 350 mA (V) 3.4 3.4 3.4

Features
• ANSI-compatible chromaticity bins


XLamp XP-G White

• Raises the bar of LED performance
– Up to 367 lumens (111 LPW) @ 1000 mA
– Reduce system cost with fewer LEDs & fewer optics

• Unbeatable efficacy at low current
– Up to 132 LPW typical @ 350 mA
– Smaller / fewer batteries or solar cells


XLamp XP-G Characteristics

Cool White 8,300K –
Min.
5,000K
CCT (K) 8,300K – 5,000K Flux
Bin 51, 53, 50
Viewing Angle 125º R5 (H) 139
Thermal Resistance (ºC/W) 6 R4 (G) 130
Max Current (mA) 1000 R3 (F) 122
R2 (E) 114
Typical Vf @ 350 mA (V) 3.0

Features
• ANSI-compliant chromaticity bins
• REACH and RoHS-compliant


XLamp XP-C/XP-E/XP-G White
Standard Order Codes

10,000K – 5,000K – 4,200K – 3,500K – 3,200K – 2,900K –
Min.
5,000K 4,200K 3,500K 3,200K 2,900K 2,700K
Flux
Bin 01, 02, 03, … E3, F4, E4 F5, E5 F6, E6 F7, E7 F8

S2 (J)* 148
R5 (H) 139 XP-G
R4 (G) 130 XP-E & XP-G
R3 (F) 122 XP-E
R2 (E) 114 XP-E & XP-C
Q5 (D) 107 107 XP-C
Q4 (C) 100 100 100
Q3 (B) 93.9 93.9 93.9 93.9
Q2 (A) 87.4 87.4 87.4 87.4 87.4
P4 (9) 80.6 80.6 80.6 80.6 80.6 80.6
P3 (8) 73.9 73.9 73.9 73.9 73.9 73.9
P2 (7) 67.2 67.2 67.2 67.2
N4 (6) 62.0 62.0 62.0
N3 (5) Minimum luminous flux @ 350 mA (lm) 56.8 56.8
* Limited quantities


XLamp XPC/XPE/XPG Part Numbering System

LEDs are purchased with Order Code; Bin Code appears on reel


XLamp MX-6 White

The new lighting-class standard for indoor LED lighting

• Best color consistency
– ANSI warm white sub-bins (75% smaller than ANSI quarter-bins)
• Best efficacy
– High lumen output with low forward voltage (3.3V typ)
• Drop-in upgrade for Nichia NS6/NS3
– Better thermal and electrical performance, same footprint


XLamp MX-6 White Characteristics & Features

Cool White Warm White
CCT (K) 8.300K – 4,300K 4,300K – 2,600K

Viewing Angle 120º 120º

Thermal Resistance (ºC/W) 5 5

Max Current (mA) 350 350

Typical Vf @ 300 mA (V) 3.3 3.3

Typical Vf @ 350 mA (V) 3.4 3.4

Features
• ANSI-compliant chromaticity bins
• REACH and RoHS-compliant


XLamp MX-6 White

8,300K – 5,000K – 4,000K 4,000K – 3,200K – 2,900K –
Min.
5,000K 4,000K 3,200K 2,900K 2,700K
Flux
Bin 51, 53,50 DZ,F4, E4, F5 E5 F6, E6 F7, E7 F8

Q5 (D) 107 [122]
Q4 (C) 100 [114] 100 [114]
Q3 (B) 93.9 [107] 93.9 [107] 93.9 [107]
Q2 (A) 87.4 [100] 87.4 [100] 87.4 [100] 87.4 [100]
P4 (9) 80.6 [92] 80.6 [92] 80.6 [92] 80.6 [92]
P3 (8) 73.9 [84] 73.9 [84]
P2 (7) 67.2 [77]

Minimum luminous flux @ 300 mA [Calculated min @ 350 mA] (lm)


XLamp MX6 Part Numbering System



XLamp MC-E White

• Cree’s 4 power chip LED package
• Offers 4x the flux of XLamp XR-E in the same footprint and
with the same lighting class performance
• Can reduce total LED system cost by reducing the number of
LEDs & optics


XLamp MC-E White Characteristics & Features

CCT (K) 10,000K – 5,000K 5,000K – 3,700K 3,700K – 2,600K


700 700 700
Max Current (mA)
(per die) (per die) (per die)
3.2 3.2 3.2
Typical Vf @ 350 mA (V)
(per die) (per die) (per die)

Features
• Accepted by U.S. DOE for ENERGY STAR lumen maintenance


XLamp MC-E White

10,000K – 5,000K – 4,200K – 3,500K – 3,200K – 2,900K –
Min.
5,000K 4,200K 3,500K 3,200K 2,900K 2,700K
Flux
Bin 01, 02, 03, … E3, F4, E4 F5, E5 F6, E6 F7, E7 F8

M 430
K 370 370 370
J 320 320 320 320
H 280 280 280
G 240 240
Minimum luminous flux @ 350 mA (lm)
Flux and chromaticity are measured with each LED die connected to independent drive circuits at 350 mA.
The flux and chromaticity are measured with all LEDs lit simultaneously.


XLamp MCE Part Numbering System



Cree XLamp LED Product Portfolio – Color

XLamp
XR-C XR-E XP-E MC-E
Footprint
7.0 x 9.0 3.45 x 3.45 7.0 x 9.0
(mm)
Max Up to Up to Up to 700 mA
Current 700 mA 1000 mA 1000 mA (per LED)

Royal Blue Royal Blue Royal Blue
Blue Blue Blue A1 (RGB CW)
Green Green Green
Colors
Amber Amber B1 (RGB NW)
Red-Orange Red-Orange
Red Red


XLamp XP-E Color

• Breakthrough color flux output
– 20% brighter than XLamp XR-C Amber, Red, Red-Orange
– 6% brighter than XLamp XR-E Royal Blue, Blue, Green
• Small footprint device
• Compatible with Lumileds Rebel optics
• Symmetric design offers matching mechanical and
optical center
– Improves optical efficiency
– More efficient secondary optics
– Easier manufacturing


XLamp XP-E Color Characteristics & Features

Royal Red-
Blue Green Amber Red
Blue Orange
DWL (nm) 450-465 465-485 520-535 585-595 610-620 620-630

Viewing Angle 130º 130º 130º 130º 130º 130º

Thermal Resistance (ºC/W) 9 9 9 15 15 15

Max Current (mA) 1000 1000 1000 500 700 700

Typical Vf @ 350 mA (V) 3.2 3.2 3.4 2.2 2.2 2.2

Features


XLamp XP-E Color

Royal Blue Blue Green Amber Red- Red
Min. Min.
Orange
Flux Flux
Bin 450-465 Bin 465-485 520-535 585-595 610-620 620-630

Q4 100
Q3 93.9
Q2 87.4
P4 80.6
15 425 P3 73.9
14 350 P2 67.2 67.2
N4 62.0
N3 56.8
Minimum radiant flux @
N2 51.7 51.7 51.7
350 mA (mW)
M3 45.7 45.7 45.7
M2 39.8 39.8 39.8
K3 35.2 35.2
K2 30.6 30.6 30.6
J0 23.5
Minimum luminous flux @ 350 mA (lm)


XLamp MC-E Color (RGBW)

• Unique RGBW LED combination
• High lumen output from a single device
– Up to 500 lm total when driven @ 700mA per die
• Reduces space between color LED die to almost nothing
– Small, multi-color optical source for efficient color mixing
– Reduces number of optics
• Lower system component count can reduce total system
complexity & cost


XLamp MC-E Color Characteristics & Features

Configuration A1 B1
Color Blue Green Red White Blue Green Red White

DWL (nm) / CCT 450-465 520-535 620-630 6500K 450-465 520-535 620-630 4000K

Min. Luminous Flux
8.2 67.2 30.6 95 8.2 67.2 30.6 80
@ 350 mA (lm)

Typical Vf @ 350 mA (V) 3.2 3.4 2.2 3.2 3.2 3.4 2.2 3.2

Max Current (mA) 700 700 700 700 700 700 700 700

Viewing Angle 115º 115º

Thermal Resistance (ºC/W) 3 3

Features
• RoHS-compliant


MPW-EZW (Easy White)

• 8-8-8 chip configuration
• 2700K, 3000K, 3500K
• No CCT binning req’d;
4-step MacAdam ellipse
• LF binned at 250mA
– ~1250 lm @ 2700K
– ~1350 lm @ 3000K
– ~1450 lm @ 3500K
• Up to 20W power dissipation
°
– 2°C/W RTH
• Typical CRI: 80
• >50,000 hrs L70 per
IES LM-80-2008
• 1Q10 general release

MPL-EZW The Big Benefit

Let Cree do the mixing for you...EasyWhite
• Consistent color
• No complicated mixing recipes
• Reduced inventory
• Ease of manufacturing
• No Special Bin Order Codes (reduce cost)


Cree LED Target Markets


The Market Outlook

HB LED Market* General Illumination Market**
Revenue (Billions)

Revenue (Billions)
Conventional
Lighting
LED
Lighting

LED market growth is being driven by two major trends:
Notebook & TV backlighting (short cycle)
General Lighting (long cycle)
** Source: Philips Lighting


LED Components – Market Segments

Indoor Lighting Portable Lighting

Outdoor Lighting LED Light Bulbs

Transportation & EVL

Video Screens & Signs Architectural


Current LED Lighting Applications


Video Screens – High Bright LEDs

Screen Master P2 Oval
C4SMG C4SMF C5SMF
Matched Radiation Red / Green / Blue

4mm – 100°x45° 4mm – 100°x45° 5mm – 100°x40°

12 – 16 mm pitch 16+ mm pitch 20+ mm pitch

SMD – Black Face
CLV1A-FKB CLV6A-FKB
Full Color (Red / Green / Blue) – Vertical Alignment

PLCC4 – 120° PLCC6 – 120°

4 – 10 mm pitch 10 – 16 mm pitch

IPx5 rated (water resistant)


Signs, Signals & Channel Letters – HB LEDs

P2 5mm Round P2 5mm Oval
C503B-xAx C503B-xBx C503B-xCx C566C-xFx
A/R/G/B A/R A/R/G/B A/R/G/B

15° 23° 30° 70°x35°

P4 Round
CP41B-xxS CP41B-xxS CP42B-xKS
A/R G/B/W A/R/G

40° / 70° / 100° 60° / 70° / 90° 120°


Outdoor (Area) Lighting is a Diverse Space

“Cobra Head” Parking/Canopy/ Industrial Parking/ Ornamental/
Low Bay “Wall Pack” “Shoe Box” Pole Top

• 60 million unit installed base in North America alone
• Most use one of three HID lamp types:

Metal
LPS HPS LED
Halide
“Boiler Plate” Efficacy (LPW) 130 95 70 105
Delivered Efficacy* (LPW) 70 51 38 75
CRI <5 22 60-80 70-80
Typical CCT 1800 2000 3000-4000 Any
Lifetime (hours) 16k 24-30k 10-20k >50k

* Incl. 60% CU + 10% ballast factor for HID; 85% CU, 88% driver efficiency, -10% thermal equilibrium for LED


Outdoor Lighting – XLamp Power LEDs

Outdoor Lighting

XLamp XR-E XLamp XP-G XLamp MC-E

Cool White (75 CRI) – 5000K-10,000K

Up to 107 lm min Up to 130 lm min Up to 430 lm min

93 lm/W 124 lm/W 96 lm/W


Making the Business Case Work

Initial applications will be driven
by maintenance avoidance &
energy savings
– Street & Parking lot lighting
– Parking garages
– Atrium
– Tunnels
– Hazardous work areas


150W MH Street Light Example
Light Source Comparison
2-3 Year Payback For End Customer
$1,200

Cumulative Lifecycle Costs 150W
$1,000 Metal Halide
Cumulative Lifecycle LED Cost
(350mA)
Cumulative Lifecycle LED Cost
$800 (700mA)

$600

$400

$200

$-
2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

LEDs make a compelling maintenance and
energy savings value proposition now


Attractive Financial Proposition For Fixture Co.

10-year Cost of Ownership*
150W MH Street Light

$1,200
Labor
Total Fixture CoO*

Bulb

$1,000
Labor Maintenance
Bulb Events
$800 Labor
Bulb

$600
Energy
Energy
$400

$200 LED
Metal Initial Fixture Fixture
Halide
Fixture Sale
$0
Conventional LED Fixture
HID Fixture


U.S. DOE Gateway Project
Rayley’s Supermarket, Chino, CA

Before: 346W Metal Halide After: 149 W Bi-level LED System
52W when dimmed

• 70% Energy Savings
• 3.3/4.7 year simple payback (new construction/retrofit)
• Perceived improvement in safefty
http://www1.eere.energy.gov/buildings/ssl/gatewaydemos_results.html


Tianjin Polytechnic University

• 2,000 roadway
luminaires installed

• Primary motivation:
Energy Savings


NC State University Parking Deck

Before: HID


NC State University Parking Deck

After: 27% Energy Savings
Vastly Improved Lighting
Less Fixtures (wider spacing)


Indoor Lighting

Indoor Lighting
XLamp XP-E XLamp MC-E XLamp MX-6 MPL-EZW
Warm White (80 CRI) – 2600K-3700K
Up to 1365 lm @
Up to 93.9 lm min Up to 320 lm min Up to 87.4 lm min
250mA
Neutral White (75 CRI) – 3700K-5000K

Up to 100 lm min Up to 370 lm min Up to 93.9 lm min


Indoor Applications

• Different requirements than
outdoor
– Warm White Color
Temperature (2700-3000K)
required
– High CRI (>80)
– Lamp maintenance not
a driving factor
– High style content
– Focus on energy, green
– Different market channels,
cost expectations (consumer
Yes, these are LED!
product)


Indoor: Restaurants

• 80% Energy Savings
• Excellent Color Rendering


Residential Installations


High-End Retail Hotel Installation


LED Light Bulb & Landscape Lighting

Linear Tube
CLA1A-xKW CLP6B-xKW XLamp MX-6
Cool / Warm White

3.2 x 2.8 mm 6.0 x 5.0 mm 6.5 x 5.0 mm
35 mA max 150 mA max 350 mA max

Light Bulb
XLamp MX-6 XLamp XP-E XLamp MC-E MPL-EZW
Cool / Warm White Cool / Neutral / Warm White Warm White

6.5 x 5.0 mm 3.45 x 3.45 mm 7.0 x 9.0 mm 13 x 12 mm

350 mA max 700 mA max 700 mA max (per
250mA per die
die)

Landscape Lighting
C503D-WAN C535A-WJN CP41B-WxS
Cool White

P2 Round – 15° P2 Round – 110° P4 Round – 60° / 90°
30000 mcd typ 1400 mcd typ 7000 mlm typ


Standard LED Components LED bulbs

Happening Now
• Longer life
• Much better efficacy than incandescent; lower
efficacy than CFL
• Generally pretty low CRI (~75-82, 3000K)
• Today, light output matches only the lowest
wattage incumbents

MR16 Using Standard LED Components

2008 6500K 3000K

2011

2008

2011
2009
2010

2012

2009
2010

2012
System Wattage System Wattage
Watts Equivalent* Watts Equivalent*
1.0 84 92 101 112 123 1.0 63 69 76 84 92
2.0 161 177 195 214 235 2.0 121 133 146 161 177
3.0 231 254 279 307 338 3.0 173 191 210 231 254
4.0 294 324 356 392 431
20W 4.0 221 243 267 294 323
5.0 351 386 425 467 514 5.0 263 289 318 350 385 20W
6.0 401 441 485 533 587 6.0 300 331 364 400 440
Limitations

7.0 444 488 537 590 649 35W 7.0 333 366 403 443 487
L70

8.0 480 528 580 638 702 8.0 360 396 435 479 527
35W
9.0 509 560 616 677 745 9.0 382 420 462 508 559
10.0 531 585 643 707 778
50W 10.0 399 438 482 531 584

• 20W halogen equivalent* @ 3000K possible now
• 35W equivalent* @ 3000K looks possible later
• 50W equivalent* @ 3000K looks challenging
• Thermal limitations inherit to the form factor
* Lumen equivalence, CBCP target probably be more practical

Portable

High-End
XLamp XR-E XLamp XP-G XLamp MC-E
Cool White
7.0 x 9.0 mm 3.45 x 3.45 mm 7.0 x 9.0 mm
Up to 107 lm min Up to 130 lm min Up to 430 lm min

Mainstream
XLamp XP-E XLamp XP-C CLN6A-WKW C503D-WAN
Cool White

3.45 x 3.45 mm 3.45 x 3.45 mm 5.0 x 5.0 mm 5mm 15°
Up to 114 lm min Up to 93.9 lm min Up to 85.6 lm min 30,000 mcd typ


Architectural, Transportation – XLamp LEDs

Architectural, Transportation Color Lighting

XLamp XP-E XLamp MC-E

Red, Green, Blue, Amber RGBW


Water Cube at Beijing Olympics 2008


Bird’s Nest at Beijing Olympics 2008


LED Design Considerations


Electrical, Thermal & Optical: All Affect Light Output

• Integrated systems approach;
Electrical fixture designed around LEDs
• LED light is different than
existing light technologies
• Not intuitive at first

Thermal

Delivered Delivered
lumens LPW

• These charts are on all LED data
sheets; familiarization with them
is essential to good results

Optical


LED Luminaire Design Will Be Different…

Conventional Lighting
LED

Reflector
Light
Heat

• LED Light is inherently directional
• LED thermal path accomplished by conduction
– No IR, no UV in the light beam
• Retrofit of conventional fixtures may not leverage
all the benefits of LEDs


Process for Designing LEDs into Luminaires

1. Define lighting requirements of application

2. Define design goals for LED luminaire

3. Estimate efficiencies of optical, thermal and electrical
subsystems

4. Calculate the number of LEDs needed

5. Build a prototype and test against design goals


1) Define Lighting Requirements

? What kind of light is required in this application?

Importance Characteristic Unit

Luminous flux lumens (lm)

Critical Illuminance distribution footcandles (fc)

Electrical power consumption Watts (W)

Luminaire aesthetics

Price

Lifetime hours

Potentially Operating temperature °C
Important Color temperature K CCT

CRI

Form factor

Ease of installation


Example CFL Down Light Characterization

Importance Characteristic Unit Value

Luminous flux lumens (lm) 1800

Critical Illuminance distribution Lux (lm/m2) (defined in IES file)

Electrical power consumption Watts (W) 23 (excluding ballast)

Lifetime hours 10,000

Color temperature K CCT 4,000
Important
CRI 75

Form factor 6 inch diameter can


Example Downlight: Critical Characteristics

Fixture :
Flux (lm)
Power (W)
Installed
Ceiling
Height

Illuminance
Distribution


Example CFL Downlight IES File

What is an IES file?
• It is basically the measurement of the far field distribution of light source
(intensity) stored in ASCII format.

1800 Source lumens
3 M Mounting Height
89 Lux peak (~40 Lux ave)
73% Luminaire Efficiency
Specular Reflector
26W total power


2) Define SSL Design Goals

? How will this new (LED) product create value?

Value:
• Same amount of light
• Same quality of light
• Longer lifetime without maintenance

Critical: Important:
• Same or more light • Same quality of light (CCT & CRI)
• Same or more homogenous • Same ambient temp rating
distribution of light • Longer lifetime
• Same or lower power
consumption


SSL Design Goals to Replace CFL Down Light

Importance Characteristic Unit Value

Luminous flux lumens (lm) 1800

Critical Illuminance distribution Lux Same as example

Electrical power consumption Watts (W) 23 (excluding driver)

Lifetime hours 50,000

Color temperature K CCT 4,000

Important CRI 75

Form factor 6 inch diameter can

Operating temperature °C 55


3) Estimate Efficiencies of Subsystems

What kind of losses need to be taken into account?
? What design solutions will best minimize these losses?

Electrical Design Goals

• 1800 lm flux
• 23 W power
LED • 50,000 hour lifetime
Thermal • 4,000K CCT
Specs
• 75 CRI
• °
55°C max temp.

Optical


Optical Losses : LED Light is Directional

High Power LED • One big advantage LED light has
compared to conventional bulb lights
is that LED lamps send light in one
direction

90° beam angle
• If an intended application only needs
to send light in one direction, keep in
mind only some of the total light
output will be useful.

Conventional Lighting • Other light will be lost to the reflector
or sent in a non-useful direction in
spite of the reflector.
Reflector

• Secondary optics will be needed if LED
beam angle does not meet the
application requirements.


Sources of Optical Loss

Secondary Optics
Reflector Coefficient of
Utilization

Lens

85%-90% Efficient Varies


LED Secondary Optics

Secondary optics are used to modify the output beam of the LED
such that the output beam of the finished lamp will efficiently
meet the desired photometric specification.

LED optics can be categorized into:
• Reflectors
• Lenses
• Combinations of lens or reflector
Generally speaking, lenses are more
efficient in shaping the beam than
reflectors.

The basic functions of the secondary optics are:
Diverging: Spread the emitted light
Colliminating : Colliminating the light into a narrower beam.


Diverging (diffusing): Spreads the light in a wider pattern

Spatial Radiation Pattern for LED only Spatial Radiation Pattern for LED with
Secondary Optics
1

0.8
LED with secondary optics 1.0
Relative Intensity

0.8

Relative Intensity
0.6
0.6

0.4
0.4

0.2 0.2

0 0.0
-100 -50 0 50 100 -100 -50 0 50 100
Angle (º) Angle (º)



Colliminating: Focus the wide beam to narrower beam

Reflector + Lens TIR Lens
Lens
Reflector

Spatial Radiation Pattern for LED with
Spatial Radiation Pattern for LED only
Secondary Optics
1
1

0.8 LED with secondary optics 0.8
Relative Intensity

Relative Intensity
0.6 0.6

0.4 0.4

0.2 0.2

0 0
-100 -50 0 50 100 -100 -50 0 50 100

Angle (º) Angle (º)


Reflectors Overview
Spillover
• Use reflective surface to collimate the LED
light output
• Have a relatively large opening and some
part of the light will never hit the surface
and become unmanaged (called spillover)
• The result of spillover is a large area of
scattered light around the main beam spot
• Are easy to make and relatively
inexpensive

• The shape of the reflector determines beam forming
− Parabolic: gathers emitting light from the focal point and redirects as
parallel beam
− Aspheric: directs light in wider angles, providing general flood lighting
• The bigger the reflector, the better the beam control will be
• The smaller the optical source size, the better a reflector can
control the beam


Total Internal Reflection (TIR) Overview

• Manages both direct and reflected light
• Light travels through at least 2 surfaces
(often more), before getting out of the
system
• Can be efficient even the size is small
• Relatively expensive compared to
reflector
Use these surfaces to further Maximum efficiency when this
shape beam pattern ray is directed to edge of outer
surface

Parabolic or elliptical
shape to direct light

Collimating Lens in front of LED


Typical Off-The-Shelf LED Secondary Optics


1
LED with secondary optics
0.8
Relative Intensity

0.6

0.4

0.2

0
Example: 6 deg spot beam
-100 -50 0 50 100
Angle (º)


Special LED Secondary Optics

Special optics (like street light, parking lot lens): Convert the lambertian
beam from LED to specific distribution needed for unique applications


1 LED with secondary optics
0.8
Relative Intensity

0.6

0.4

0.2

0
-100 -50 0 50 100
Angle (º)


Potential Downlight Optical Solution

Use wide beam TIP optics to achieve best efficiency and control
• Slightly more narrow beam
Reduces total lumens required to achieve same illuminance

Only 700 Source lumens
3 M Mounting Height
100 Lux peak (~40 Lux ave)
90% Optical Efficiency

Ledil LXP Wide


Thermal Losses

Unlike traditional bulbs,
light is emitted in one
direction and heat goes
out the other

Unlike traditional 5mm LEDs,
power LEDs have separate
paths for electrical & heat flow


Where is the LED Junction?

LED
Junction

• LED junction is located within the LED package
• LED junction temperature (Tj) cannot be measured directly


High Power LED Thermal Resistance

Thermal resistance quantifies how easily heat flows between the LED
junction and the LED’s thermal path.
• Lower thermal resistance = better thermal flow

How to Measure Junction Temperature
1. Wait for LED(s) to reach thermal
equilibrium
j 2. Measure solder point temperature
3. Measure voltage & current
4. Calculate power & Tj

Tj = Tsp + Rth j-sp * Power
sp

Rth j-sp: Thermal resistance between junction (j) and solder-point (sp)
• Unit: °C/W or Kelvin/W
• Lower Rth j-sp = lower temperature difference between j & sp


Thermal Losses

Light output vs. increased junction temperature Tj


LED Junction Temperature vs. Lifetime

• Tj affects LED lifetime & long-term lumen maintenance

°
Tj (°C) L70

X 51,000 hrs

X + 10 44,000 hrs

X + 20 38,000 hrs


LED Junction temperature vs Forward Voltage

• Temperature coefficient of Voltage
°
– -mV/°C

• As the Junction temperature increases the forward voltage
decreases.
Example: 10 LEDs in series
Vf @ Tj 25°C = 3.3V
Total voltage = 10 * 3.3 = 33V
After warm up Tj = 60 °C
Vf = 3.3 –(.004*35) = 3.16V
Total Voltage = 10*3.16 = 31.6
This example shows that using a constant current
driver is very important.

LED Junction temperature vs Wavelength/CCT

As the Junction temperature increases, wavelength
or CCT can shift

Color K
R e la t iv e I n t e n s it y

(nm/ºC)
2
Amber .09

Red .03
Amber
1
Blue .04

Green .04
0
570 580 590 600 610 620 630 Cyan .04
Wavelength [nm]


Heatsink Selection/Design

• Manage heat to maximize
performance
– Integrate heatsink into fixture
housing
– Used thermal pads, tapes … to
achieve best coupling between
PCB and heatsink
– Retrofits may not perform well
– Run thermal simulation to
determine heatsink Rth required
– Select proper PCB material, size,
shape to maximize heat transfer
to ambient (lowest Rth)


Typical Power LEDs with MCPCB

• MCPCB Advantages
– Low Thermal Resistance
– High reliability (rigid)
• But can be expensive

Cu top layer
35 – 70 µm

Dielectric layer
70 – 200 micron
σ = 0.3 – 3 W/mK

Metal Clad Substrate


XLamp Does Work with FR4 too

XLamp

+ -

Series
Isolated thermal path
(electrically neutral) LED
+ - Circuit

FR4

Copper Plane Copper Thermal Vias
(50-70 um)

• With its isolated thermal path, XLamp does not have any
problem with shorting through the thermal plane
• FR4 is easy for all manufacturers, can achieve low Rth


Electrical Losses

90

85
Efficiency (%)

80

75

70

65

60
0 20 40 60 80 100
Output Load (%)

Generally, 85% - 90% is a good estimate for LED drivers, except
for high ambient temps or long lifetime


LED Drivers

Why do XLamp LEDs need drivers?

• Light output is a function of current
– To supply constant current to the LEDs
• LEDs are low voltage devices
– To transform AC to LED low voltage DC
– High voltage DC to LED low voltage DC
• To protect the LEDs from being overdriven and
from transient voltages
• Provide accurate dimming control


LED Electrical Design

Goal: Control light output of LED system

• LED light output varies with current

250
Relative Intensity (%)

200

150

100

50

0
0 200 400 600 800 1000
Forward Current (mA)


Voltage Variation in High Power LEDs

1000

900

800

700

600 Datasheet

500 LED1
LED2
400
LED3
300 LED4
200 LED5

100

0
2.5 3.0 3.5 4.0
Forward Voltage (V)

Vf to achieve If = 350 mA: 3.2 V – 3.4 V

• Every LED lamp has a slightly different relationship between voltage
& current
• Very few parts perform exactly as shown on the datasheet


Voltage Variation in High Power LEDs

Why is constant current drive important?
1000

900

800

700

600 Datasheet

500 LED1
LED2
400
LED3
300 LED4
200 LED5

100

0
2.5 3.0 3.5 4.0
Forward Voltage (V)

If at Vf = 3.4 V: 350 mA – 675 mA

Result is relative LED brightness from 100% to 165%!
Constant voltage drive is NOT recommended

Series Array

Advantages Disadvantages
• All LEDs at same current and • Voltage increases linearly with
same relative luminous flux number of LEDs in string
• One LED failing to open circuit
will cause entire string to cease
light output

Note: If Xlamp LED does ever fail due to internal catastrophic or
thermal issue, it will usually fail as short circuit


Series Array (With Zener Diodes)

• All LEDs at same current and • Voltage increases linearly with
same relative luminous flux number of LEDs in string
• LED failing to open circuit will • Higher cost than Series Array
only affect one LED, not the
entire string


Parallel Array

• Many LEDs powered from just • Potential for current hogging
one voltage drop
• One LED failing to short circuit
• One LED failing open will not will cause the entire array to
affect any other LEDs cease light output


Series-Parallel Array

• Relationship between number • Resistors in each string waste
of LEDs and voltage is power as heat, affecting the
configurable thermal design of the entire
system
• One LED failing to open circuit
will only affect one LED string,
not all LEDs


Constant Current LED Driver

Buck Regulator
AC-DC or DC-DC

• Excellent current regulation • Higher relative cost
• High efficiency • More complex circuit design
• High power density • Possibly higher EMI
• Precise dimming capability • Less common than constant-
voltage


Dimming/Strobing LEDs

Pulse Width Modulation (PWM)
• Drive LED lamps at same peak current but at low duty cycle
• Eliminates matching problems from driving at low currents
• PWM frequency of at least 200 Hz
– < 70 Hz produces visible flicker,
– < 100 Hz: strobe effects of moving LED
– > 1000 Hz: possible EMC problems
• Best method for brightness control (dimming)
• Applications
– EVL Flashing, Beacon Strobing, Color Changing/Mixing

Duty Factor (%) = ton/(ton+toff)*100

If DF=50% ton toff

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 time(ms)


Constant Current Driver Selection

Modular vs. IC-based
Power Modules IC power solutions

Main
ready-to-use, fully tested smaller, more cost effective
Advantage

customers with no
Best dimming, flashing, and
Allows electronics knowledge to
color controlling
work with the LEDs
Dimming, UL & IP rated,
Wide VAC (120-277V) &
other wide VAC (120-277V) &
VDCin, >90% efficiency (DC
Features VDCin, high PF, up to 90%
solutions), high PF
efficiency

Prototyping, low volume LED high volume production or if
Ideal for
applications custom drive is required


Driver Examples

AC-DC Module

DC-DC IC design


Other Driver Considerations

• Will drivers last for life of LEDs
– 50000 hours usable life
– Identify components at risk of early failure and
substitute with longer life (cost, size, …)
– De-rate component specs accordingly for extreme
operation conditions; improve reliability
• Does system require sealed driver (IP ratings)?
• Is isolation required (for safety approvals)


Review of Subsystem Efficiencies

Subsystem Efficiency Type
Optical 90% Light
Thermal 85% Light
Electrical 87% Power

Only optical & thermal losses will affect the # of LEDs needed to
meet the design goals

Electrical efficiency only affects the total “wall-plug” efficiency
of the luminaire


4) Determine Number of LEDs

? How do I calculate how many LEDs are needed?

• Calculate based on optical and thermal losses

OR for an easier method

• Use Cree Product Characterization Tool
Register @ pct.cree.com/Register.asp


General Layout


Define the Desired Parameters


Select LED Type, Flux Bin and Temperature

• Be careful to select the
bins that exist FOR THE
CCT you are seeking (e.g.
E7 kit, or 7B Bin, etc)
• Tj or Ts is usually an
„Engineering Estimate“


Select Target Lumens and Efficiencies


Comparing the Calculations

• How does
the XP-G
compare
to the XP-
E when
run at
500mA?
• Second-
highest
bin
selected.


Our Downlight Example Characterization


… Comparison to conventional sources

WARM WHITE

Incand
Delivered Efficacy
x Fixture Efficiency
= 10 lm/W
“17 lm/W” 58%

CFL
Delivered Efficacy
x Fixture Efficiency = 35 lm/W
“60 lm/W” 58%

CA
Title 24
LED
Optical Efficiency 85%
Delivered Efficacy
x = 70 lm/W
“80 lm/W” x Driver Efficiency 85%

x Thermal Equilibrium 88%*


What Drive Current to Use?

Operating Current Pros Cons

• Higher efficacy (lm/W)
• Less flux per LED (more
Lower • Longer LED lifetime
LEDs in system)
• Better lumen maintenance

• Reduced efficacy (lm/W)
• More flux per LED (fewer • Reduced maximum
Higher LEDs in system) ambient temperature
OR
Decreased lifetime

Decision on operating current should be driven by
the design goals

Example down light = low drive current (350 mA)


LED Lifetime Is Irrelevant

System Design is What Creates Value, Quality
Heat Sink: Linchpin of the entire system.
If this is poorly designed, all the other
components can be compromised

Driver: Currently the weakest
point of the system, but the big
companies are working on this
LED Lamps: Practically never
fail; depreciate very slowly in a
well-designed system

Optical Components: Can
(rarely) yellow over time and
lose light; system design choice


Quality Matters – Optical Design & Poor LEDs

Need Lighting-class LEDs


Quality Matters – Poor LED Selection
16.5” Lowes
Time zero 1000 hours

LED Puck
84.1% Drop

16.5” Linear
97.8% Drop

22” Linear
96.9% Drop


Quality Matters – Driver & Thermal Problems

• Driver/circuit board
failure

• Color Shift Due to poor
thermal design


Coping With Rapid Change in LED Performance

Modular Approach to MH Source Replacement

Driver Generic LED Strip
Circuit
(optional)

Fixed Number of LEDs
Generation 1 Generation 2 Generation 3

A modular design approach can yield constant photometric output while
facilitating ongoing cost reductions each time LED brightness is improved



Aim Ahead of the Duck…

LF Distribution

0.8*$X $X 1.2*$X

0.8*$X $X 1.2*$X

Prototyping with the highest performance LEDs currently available is more expensive, but
can yield a more competitive and longer life product over the long term



Plan for BOM savings

Generation 1 Generation 2

25% brighter LEDs can also mean 25% fewer LEDs. Need to plan flexibility
in your driver design to accomplish this


Design & Specification Strategies
Strategy #1 Strategy #2

• Insist on the tightest bin • Understand light, binning,
available and your application needs
• Pay the highest price • Do the mixing yourself in
possible your fixture if the
• NOT a good approach application will allow it
• Save money

LED Roadmaps


DOE Roadmap

200
Efficacy (lm/W)

150

Cree cool white production
100 Cree warm white production
Laboratory Projection - Cool White
Commercial Product Projection - Cool White
Commercial Product Projection - Warm White
50 Laboratory - Cool White
Commercial Product - Cool White
Commercial Product - Warm White
Maximum Efficacy - Warm White
Maximum Efficacy - Cool White
0
2004 2006 2008 2010 2012 2014 2016 2018 2020
Year
US Department of Energy 2009 Multi-Year Plan for SSL

How the Roadmap Really Works: Chip Improvement

150
LF @ 350mA (lumens)

Next Generation

100
Current Generation

50
Last Generation

Time

• Major leaps forward on LF depends on major chip
improvements
• Incremental chip improvements, phosphor efficiency, and
learning curve historically improves 1-2 LF bins as well


LED Performance vs. Traditional Light Sources
Light Source Efficiency Trends
180 187
R&D Best
160 LED
140
Current LED
120
Lumens/watt

HID
100
Linear Fluorescent
80
3 Years ago LED
60 CFL
40
20 Incandescent

0
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012


Brightness/Efficacy Roadmap (XP-E Cool White)
Lumens / LPW*

139 (R5) / 128

130 (R4) / 120

122 (R3) / 112

Oct 2009 114 (R2) / 105

107 (Q5) / 99

2008 2009 2010

* Mid-Point in Production


Real LED Levels of Performance (2012)

6000K 4100K 3500K 2700K
Data Sheet LPW 165 136 136 107
*
Typical Thermal Loss 10% 10% 10% 10%
*
Typical Optical Loss 10% 10% 10% 10%
*
Typical Driver Loss 15% 15% 15% 15%
*
Achievable LPW 107 88 88 70

CRI ~75 ~80 ~82 ~83

* Typical with average/good design practices

• LEDs will be the most efficient mainstream
source available
– >100 delivered LPW roadway light possible
– Indoor fixtures >80LPW (wall-plug)


Cree Support and
Partnerships


Cree Support

South America Services Provided
GDE, Led do Brasil • Cree XLamp expertise
• LED Design consulting
• Customized design
• LED engines
Contact: Paulo Taminato • Turnkey solutions
Cree Lighting Agent • Sub-assembly


Cree XLamp Solutions Partners

Secondary Optics Drivers
BrightView Technologies Allegro
Carclo Austria microsystems
Fraen Infinilux
G&L Intersil
Genius Magtech
ideaLED Maxim
Khatod Microchip
LEDiL National Semiconductor
LedLink Optics NXP
LTI Optics ON Semiconductor
Luminit ROHM Semiconductor
Polymer Optics Zetex Semiconductors
RPC Photonics

Lists on Cree Website
Secondary Optics http://www.cree.com/products/xlamp_part.asp
Drivers http://www.cree.com/products/xlamp_drivers.asp


Cree Products Summary

Single Die White Multiple Die White
XLamp
XR-C XR-E XP-C XP-E XP-G MC-E MX-6

XLamp
XR-C XR-E XP-E MC-E


Ssl Training December 2009 [Compatibility Mode]

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