L8957
Features
Applications
L E D
Infrared LED
l Low price
Uses low cost lens
l Optical encoders
l Optical switches
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.
1
1
I Absolute maximum ratings (Ta=25 C, unless otherwise noted)
Parameter
Symbol
Value
Unit
Reverse voltage
V
4
5
V
Forward current
I
.
80
mA
Forward current reduction rate
-
0.67
mA/C
Pulse forward current
I
.2
0.5
A
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
I Electrical and optical characteristics (Ta=25 C)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Unit
Peak emission wavelength
lp
I
.
=50 mA
840
870
900
nm
Spectral half width
Dl
I
.
=50 mA
-
45
-
nm
Radiant flux
fe
I
.
=50 mA
3.4
5.8
-
mW
Forward voltage
V
.
I
.
=50 mA
-
1.6
1.75
V
Reverse current
I
4
V
4
=5 V
-
-
5
A
Spot light size *
Bw
I
.
=30 mA
4.5
5.0
-
mm
Optical output *
Pe
I
.
=30 mA
1.0
2.0
-
mW
Cut-off frequency *
!
fc
I
.
=30 mA 4 mAp-p
25
40
-
MHz
*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.
Infrared LED
L8957
2
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: Smidesvgen 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
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.
Cat. No. KLED1039E01
Aug. 2002 DN
2
RELATIVE RADIANT OUTPUT (%)
(Typ. Ta=25 C)
80
%
40 %
60 %
20
%
20
10
0
10
20
90
80
50
40
30
70
60
90
80
50
40
30
70
60
100 %
0
20
40
60
80
100
-3
-2
0
-1
+1
+2
AMBIENT TEMPERATURE (C)
RELATIVE RADIANT OUTPUT (dB)
(Typ. I
F
=50 mA)
-40
-20
0
20
(Typ.)
40
60
80
100
0
40
60
80
100
AMBIENT TEMPERATURE (C)
RELATIVE ALLOWABLE FORWARD CURRENT (%)
20
0
-4
-3
-2
-1
0
2
3
1
POSITION ON IMAGE SENSOR (mm)
RELA
TIVE RADIANT OUTPUT (%)
4
20
40
60
80
100
L
LED
IMAGE
SENSOR
L=5 mm
(Typ. Ta=25 C)
L=8 mm
L=10 mm
KLEDA0077EA
KLEDB0248EA
I Dimensional outline (unit: mm)
I Light intensity distribution
I Allowable forward current vs. ambient temperature
I Directivity
I Forward current vs. forward voltage
I Radiant output vs. ambient temperature
0
0.5
1.0
1.5
2.0
40
20
60
80
100
FORWARD VOLTAGE (V)
FORWARD CURRENT (mA)
(Typ. Ta=25 C)
KLEDB0227EA
KLEDB0247EA
KLEDB0228EA
KLEDB0229EB
4.65 0.15
3.7 0.2
4.7 0.3
13.5 1.0
5.4 0.2
(0.4)
0.6 MAX.
2.54 0.2
0.45
LEAD
COMMON TO CASE
PDF 
ZIP