Datasheet

V
R
[V] reverse voltage
V
RL
[V] voltage at current limiting resistor
V
S
[V] voltage of (constant voltage) source or battery
V
Z
[V] Zener or break through voltage of Z-diode
x n°
[ - ] x coordinate in CIE color space for n-degree observer (usually n = 2
is used with light sources like LEDs: x
2°
)
y n°
[ - ] y coordinate in CIE color space for n-degree observer (usually n = 2
is used with light sources like LEDs: y
2°
)
2 ψ [°] viewing angle (usually at half of maximum intensity)
Abbreviations
The following abbreviations are used in the application notes. Please note that not all of these
abbreviations are used in this particular note.
ACULED
®
The trademarked name for Excelitas’ range of All Color Ultrabright LEDs.
BOM Bill of Material
ccw counter clockwise
CCT Correlated Color Temperature
CIE Commission Internationale de l'Eclairage = International Commission on
Illumination
COB Chip-on-Board
CRI Color Rendering Index, value to measure the quality of light used for illumination
purposes.
DMX Digital Multiplex, serial light communication protocol (DMX-512)
DYO
TM
Design-Your-Own, indicates an ACULED with customized chip configuration
DUT Device Under Test
ESD Electro Static Discharge, Electro Static Damage, Electro Static Sensitive Device
FR4 Flame resistant 4, low cost PCB material made from epoxy resin and fiberglass
mat
FWHM Full Width at Half Maximum
IMS Insulated Metal Substrate, PCB substrate made from aluminum or copper to
provide excellent heat management
IR Infra Red, radiation above 700 nm within the scope of this application note
LED Light Emitting Diode
NTC Negative Temperature Coefficient, used as acronym for an NTC resistant.
Thermistor to control (LED-) temperature
PCB Printed Circuit Board
PD Photo Diode
www.excelitas.com Driving the ACULED® VHL™ 27