Datasheet

Symbols and Units
The following terms and their typical units are used in the application notes and datasheets of the
ACULED. Please note that not all of these are used in this particular note.
A [m²] area, surface
A
rad
[mm²] radiating surface
Cn [ - ] chip pad number n in the ACULED
C
PD
[pF] capacitance of PD
c
R
[k Ω ] coefficient used for NTC calculation
c
T
[°C] coefficient used for NTC calculation
d
PWM
[%] duty cycle PWM
E
e
[W/m²] irradiance
E
V
[lx] illuminance [lux]
f
PWM
[Hz] frequency of PWM pulses
Φ
e
[mW] radiant flux
Φ
V
[lm] luminous flux [lumen]
I
D
[nA] dark current of PD
I
e
[W/sr] radiant intensity
I
F
[mA] forward current
I
F PWM
[mA] forward current used with PWM
I
F sum
[mA] summary forward current of parallel connected LED chips
I
FM
[mA] surge current
I
Ph
[µA] photo current of PD
I
R
[µA] reverse current
I
V
[cd] luminous intensity [candela]
L
e
[W/(m²·sr)] radiance
L
V
[cd/m²] luminance
∆λ [nm] spectral half bandwidth (usually FWHM)
λ
dom
[nm] dominant wavelength
λ
peak
[nm] peak wavelength
η [%] efficiency
η
opt
[lm/W] optical (luminous) efficacy
P
Cn
[W] power consumption of chip placed on pad n of the ACULED
P
opt
[mW] output power (optical)
P
tot
[W] power consumption (electrical) [Watt]
R [ Ω ] (electric) resistance
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