HAMAMATSU L8957 Datasheet
LED
Infrared LED
L8957
Low cost LED ideal for optical encoders
L8957 is an infrared LED using a low-cost lens and available at a lower price than other products up to now.
Features Applications
l
Low price
Uses low cost lens
l
Optical encoders
l
Optical switches
■ Absolute maximum ratings (Ta=25 °C, unless otherwise noted)
Parameter Symbol Value Unit
Reverse voltage V
Forward current I
Forward current reduction rate - 0.67 mA/°C
Pulse forward current I
Pulse forward current reduction rate - 7 mA/°C
Power dissipation P 150 mW
Operating temperature Topr -30 to +85 °C
Storage temperature Tstg -40 to +100 °C
4
.
.2
5V
80 mA
0.5 A
■ Electrical and optical characteristics (Ta=25 °C)
Parameter Symbol Condition Min. Typ. Max. Unit
Peak emission wavelength
Spectral half width
Radiant flux feI.=50 mA 3.4 5.8 - mW
Forward voltage V.I.=50 mA - 1.6 1.75 V
Reverse current I
Spot light size *
Optical output *
Cut-off frequency *
*1: Full width at half maximum, measurement distance (from the image sensor to the bottom surface of L8957s base)=10 mm
*2: Measurement distance [from the photodiode (active area: f8 mm) to the bottom surface of L8957s base]=10 mm
*3: Frequency at which the optical output drops by -3 dB from that at 100 kHz.
!
pI.=50 mA 840 870 900 nm
l
I.=50 mA - 45 - nm
Dl
V4=5 V - - 5 µA
4
Bw I.=30 mA 4.5 5.0 - mm
Pe I.=30 mA 1.0 2.0 - mW
fc I.=30 mA ± 4 mAp-p 25 40 - MHz
1
1
Infrared LED
4.65 ± 0.15
3.7 ± 0.2
4.7 ± 0.313.5 ± 1.0
5.4 ± 0.2
(0.4)0.6 MAX.
2.54 ± 0.2
0.45
LEAD
COMMON TO CASE
L8957
■ Directivity ■ Forward current vs. forward voltage
20˚ 10˚ 0˚ 10˚ 20˚
30˚
40˚
50˚
60˚
70˚
80˚
90˚
RELATIVE RADIANT OUTPUT (%)
100 %
80
%
60 %
40 %
20
%
■ Radiant output vs. ambient temperature
+2
+1
0
(Typ. Ta=25 ˚C)
(Typ. IF=50 mA)
30˚
40˚
50˚
60˚
70˚
80˚
90˚
KLEDB0247EA
100
80
60
40
20
FORWARD CURRENT (mA)
0 0.5 1.0 1.5 2.0
(Typ. Ta=25 ˚C)
FORWARD VOLTAGE (V)
■ Allowable forward current vs. ambient temperature
100
80
60
KLEDB0227EA
(Typ.)
-1
-2
40
20
RELATIVE RADIANT OUTPUT (dB)
-3
0 20 40 60 80 100
AMBIENT TEMPERATURE (˚C)
KLEDB0228EA
0
RELATIVE ALLOWABLE FORWARD CURRENT (%)
-40 -20 0 20
40 60 80 100
AMBIENT TEMPERATURE (˚C)
■ Dimensional outline (unit: mm)■ Light intensity distribution
100
L=5 mm
80
60
40
20
RELATIVE RADIANT OUTPUT (%)
0
-4 -3 -2 -1 0 2 31
POSITION ON IMAGE SENSOR (mm)
LED
L
HAMAMATSU PHOTONICS K.K., Solid State Division
1126-1 Ichino-cho, Hamamatsu City, 435-8558 Japan, Telephone: (81) 053-434-3311, Fax: (81) 053-434-5184, http://www.hamamatsu.com
U.S.A.: Hamamatsu Corporation: 360 Foothill Road, P.O.Box 6910, Bridgewater, N.J. 08807-0910, U.S.A., Telephone: (1) 908-231-0960, Fax: (1) 908-231-1218
Germany: Hamamatsu Photonics Deutschland GmbH: Arzbergerstr. 10, D-82211 Herrsching am Ammersee, Germany, Telephone: (49) 08152-3750, Fax: (49) 08152-2658
France: Hamamatsu Photonics France S.A.R.L.: 8, Rue du Saule Trapu, Parc du Moulin de Massy, 91882 Massy Cedex, France, Telephone: 33-(1) 69 53 71 00, Fax: 33-(1) 69 53 71 10
United Kingdom: Hamamatsu Photonics UK Limited: 2 Howard Court, 10 Tewin Road, Welwyn Garden City, Hertfordshire AL7 1BW, United Kingdom, Telephone: (44) 1707-294888, Fax: (44) 1707-325777
North Europe: Hamamatsu Photonics Norden AB: Smidesvägen 12, SE-171 41 Solna, Sweden, Telephone: (46) 8-509-031-00, Fax: (46) 8-509-031-01
Italy: Hamamatsu Photonics Italia S.R.L.: Strada della Moia, 1/E, 20020 Arese, (Milano), Italy, Telephone: (39) 02-935-81-733, Fax: (39) 02-935-81-741
2
2
(Typ. Ta=25 ˚C)
L=8 mm
L=10 mm
IMAGE
SENSOR
4
Information furnished by HAMAMATSU is believed to be reliable. However, no responsibility is assumed for possible inaccuracies or omissions.
Specifications are subject to change without notice. No patent rights are granted to any of the circuits described herein. ©2002 Hamamatsu Photonics K.K.
KLEDB0229EB
KLEDA0077EAKLEDB0248EA
Cat. No. KLED1039E01
Aug. 2002 DN
Loading...