12
Electrical
These light bars are composed of two, four, or eight light
emitting diodes, with the light from each LED optically
scattered to form an evenly illuminated light emitting
surface.
The anode and cathode of each LED is brought out by
separate pins. This universal pinout arrangement allows
the LEDs to be connected in three possible congura-
tions: parallel, series, or series parallel. The typical for-
ward voltage values can be scaled from Figures 4 and
9. These values should be used to calculate the current
limiting resistor value and typical power consumption.
Expected maximum VF values for driver circuit design
and maximum power dissipation, may be calculated us-
ing the following VFMAX models:
AlGaAs Red HLCP-X100 series
VFMAX = 1.8 V + IPeak (20 Ω)
For: IPeak ≤ 20 mA
VFMAX = 2.0 V + IPeak (10 Ω)
For: 20 mA ≤ IPeak ≤ 45 mA
Optical
Size of Light
Emitting Area
Surface Area
Sq. Metres Sq. Feet
8.89 mm x 8.89 mm 67.74 x 10–6 729.16 x 10–6
8.89 mm x 3.81 mm 33.87 x 10–6 364.58 x 10–6
8.89 mm x 19.05 mm 135.48 x 10–6 1458.32 x 10–6
3.81 mm x 19.05 mm 72.85 x 10–6 781.25 x 10–6
The radiation pattern for these light bar devices is ap-
proximately Lambertian. The luminous sterance may be
calculated using one of the two following formulas:
HER (HLMP-2300/2600/2900), Yellow (HLMP-
2400/2700/2900) and Green (HLMP-2500/2800/2900)
series
VFMAX = 1.6 + IPeak (50 Ω)
For: 5 mA ≤ IPeak ≤ 20 mA
VFMAX = 1.8 + IPeak (40 Ω)
For: IPeak ≥ 20 mA
The maximum power dissipation can be calculated for
any pulsed or DC drive condition. For DC operation,
the maximum power dissipation is the product of the
maximum forward voltage and the maximum forward
current. For pulsed operation, the maximum power dis-
sipation is the product of the maximum forward voltage
at the peak forward current times the maximum average
forward current. Maximum allowable power dissipation
for any given ambient temperature and thermal resist-
ance (RqJ-A) can be deter mined by using Figure 2 or 7. The
solid line in Figure 2 or 7 (RqJ-A of 600/538 C/W) represents
a typical thermal resistance of a device socketed in a
printed circuit board. The dashed lines represent achiev-
able thermal resistances that can be obtained through
improved thermal design. Once the maximum allowable
power dissipation is determined, the maximum pulsed
or DC forward current can be calculated.
where:
ITEST = 3 mA
for AlGaAs Red (HLMP-X000 series) 20 mA
for HER, Yellow and Green (HLMP-2XXX series)
Example:
For HLMP-2735 series
hIPEAK = 1.18 at IPEAK = 48 mA
IAVG
Iv TIME AVG =
ITEST
12 mA
Iv TIME AVG =
20 mA
[ ]
[ ]
Iv (cd)
Lv (cd/m 2) =
A (m 2)
πIv (cd)
Lv (footlamberts) =
A (ft 2)
(ηIPEAK ) (I v Data Sheet)
(1.18) (35 mcd)
IAVG
Iv TIME AVG =
ITEST
12 mA
Iv TIME AVG =
20 mA
[ ]
[ ]
Iv (cd)
Lv (cd/m 2) =
A (m 2)
πIv (cd)
Lv (footlamberts) =
A (ft 2)
(ηIPEAK ) (I v Data Sheet)
Refresh rates of 1 kHz or faster provide the most ecient
operation resulting in the maxi mum possible time aver-
age luminous intensity.
The time average luminous intensity may be calculated
using the relative eciency character istic of Figure 3 or
8, hIPEAK, and adjusted for operating ambient tempera-
ture. The time average luminous intensity at TA = 25°C is
calculated as follows:
12 mA
Iv TIME AVG =
20 mA
[ ]
[ ]
Iv (cd)
Lv (cd/m 2) =
A (m 2)
πIv (cd)
Lv (footlamberts) =
A (ft 2)
(ηIPEAK ) (I v Data Sheet)
(1.18) (35 mcd)
= 25 mcd