Hamamatsu L8957 Low cost led ideal for optical encoder 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
l Optical encoders
l Optical switches
Uses low cost lens
■ Absolute maximum ratings (Ta=25 °C, unless otherwise noted)
Parameter
Reverse voltage
Forward current
Forward current reduction rate
Pulse forward current
Pulse forward current reduction rate
Power dissipation
Operating temperature
Storage temperature
Symbol
VR
IF
IFP
Condition
Pulse width=10 µs
Duty ratio=1 %
P
Topr
Tstg
Value
5
80
0.67
Unit
V
mA
mA/°C
0.5
A
4.2
150
-30 to +85
-40 to +100
mA/°C
mW
°C
°C
■ Electrical and optical characteristics (Ta=25 °C)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Unit
Peak emission wavelength
IF=30 mA
840
870
900
nm
λp
Spectral half width
IF=30 mA
45
nm
∆λ
Optical output *1
Pe
IF=30 mA
1.5
2.1
mW
Forward voltage
VF
IF=30 mA
1.5
1.65
V
Reverse current
IR
VR=5 V
5
µA
Spot light size *2
Bw IF=30 mA
4.8 *3
5.4
mm
4
Cut-off frequency *
fc
IF=30 mA ± 4 mAp-p
25
40
MHz
*1: Measured with a photodiode (active area: φ8 mm) installed 10 mm away from LED stem undersurface.
*2: Full width at half maximum of beam spot measured with an image sensor installed 13 mm away from LED stem undersurface.
*3: Reference value
*4: Frequency at which the optical output drops by -3 dB from that at 100 kHz.
1
Infrared LED
■ Emission spectrum
(Typ. Ta=25 ˚C)
100
6
90
OPTICAL OUTPUT (mW)
60
40
20
FORWARD CURRENT (mA)
5
80
4
3
2
1
80
70
60
50
40
30
20
10
0
0
800
900
1000
0
20
40
60
KLEDB0218EA
■ Directivity
0˚
10˚
20˚
30˚
RELATIVE RADIANT OUTPUT (dB)
30˚
80
%
60 %
40˚
50˚
40˚
50˚
40 %
60˚
60˚
20
%
70˚
70˚
80˚
80˚
90˚
90˚
KLEDB0227EB
(Typ.)
0
-1
-2
-3
0
20
40
60
80
100
AMBIENT TEMPERATURE (˚C)
100
80
60
40
20
0
-40
-20
0
20
40
60
80
100
AMBIENT TEMPERATURE (˚C)
KLEDB0247EA
KLEDB0228EA
KLEDB0229EB
■ Dimensional outline (unit: mm)
■ Light intensity distribution
(Typ. Ta=25 ˚C)
10000
2.0
■ Allowable forward current vs. ambient
temperature
+1
RELATIVE RADIANT OUTPUT (%)
■ Allowable forward current vs.
duty ratio
1.5
(Typ. IF=50 mA)
+2
100 %
1.0
KLEDB0300EB
■ Radiant output vs. ambient
temperature
(Typ. Ta=25 ˚C)
10˚
0.5
FORWARD VOLTAGE (V)
FORWARD CURRENT (mA)
WAVELENGTH (nm)
20˚
0
100
80
RELATIVE ALLOWABLE FORWARD CURRENT (%)
0
700
5.4 ± 0.2
(Typ. Ta=25 ˚C)
100
4.65 ± 0.15
PULSE WIDTH=10 µs
100
10
0.01
PULSE WIDTH=100 µs
3.7 ± 0.2
(0.4)
1000
L=15 mm
L=25 mm
60
0.6 MAX.
PULSE WIDTH=1 µs
80
40
13.5 ± 1.0 4.7 ± 0.3
L=10 mm
RELATIVE RADIANT OUTPUT (%)
ALLOWABLE FORWARD CURRENT (mA)
■ Forward current vs. forward voltage
(Typ. Ta=25 ˚C)
(Typ. Ta=25 ˚C, IF=30 mA)
100
RELATIVE RADIANT OUTPUT (%)
■ Optical output vs. forward current
L8957
0.45
LEAD
20
IMAGE
SENSOR
LED
L
2.54 ± 0.2
0
0.1
1
10
100
DUTY RATIO (%)
-4
-3
-2
-1
0
1
2
3
4
POSITION ON IMAGE SENSOR (mm)
KLEDB0288EA
KLEDB0248EB
COMMON TO CASE
KLEDA0077EA
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. ©2007 Hamamatsu Photonics K.K.
HAMAMATSU PHOTONICS K.K., Solid State Division
1126-1 Ichino-cho, Higashi-ku, Hamamatsu City, 435-8558 Japan, Telephone: (81) 53-434-3311, Fax: (81) 53-434-5184, 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.: 19, 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
Cat. No. KLED1039E03
Aug. 2007 DN
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