Datasheet

R
a
[ - ] CRI (average value of testing colors R
1
to R
8
)
R
LED
[ Ω ] (internal) LED resistance
R
NTC
[ Ω ] NTC resistance (function of T)
R
PD
[ Ω ] series resistance of PD
R
RL
[ Ω ] current limiting resistance
R
th
[K/W] thermal resistance (general) [Kelvin per Watt]
R
th BA
[K/W] thermal resistance from base (B) backside to ambient surrounding
(A)
R
th JA
[K/W] thermal resistance from junction (J) to ambient air or surrounding (A)
R
th JB
[K/W] thermal resistance from junction (J) to base (B) backside
RH [%] relative humidity
T [°C] or [K] temperature (general)
t [s] time
T
A
[°C] ambient temperature
T
B
[°C] base temperature on back side of package (substrate)
T
CT
[K] (correlated) color temperature
T
J
[°C] junction temperature
t
Life
[h] life time of LED chip or module
T
NTC
[°C] temperature inside NTC chip
T
op
[°C] operating temperature
t
P
[s] on-time at PWM pulse representing the pulse width
T
sold
[°C] soldering temperature (at backside of the ACULED VHL)
T
st
[°C] storage temperature
∆ T
BA
[K] difference between base and ambient temperature
∆ T
JB
[K] difference between junction and base temperature [Kelvin]
∆ T
JA
[K] difference between junction and ambient temperature
TC
Φ
e
[mW/K] temperature coefficient of radiant flux
TC
Φ
V
[mlm/K] temperature coefficient of luminous flux
TC
λ
dom
[nm/K] temperature coefficient of dominant wavelength
TC
λ
peak
[nm/K] temperature coefficient of peak wavelength
TC
VF
[mV/K] temperature coefficient of forward voltage
V
BR
[V] breakdown voltage
V
F
[V] forward voltage
V
F sum
[V] summary forward voltage of serially connected LED chips
V
OC
[mV] open circuit voltage of PD
V
Out
[V] output voltage
www.excelitas.com Driving the ACULED® VHL™ 26