5200 St. Patrick St., Montreal
The Old Railway, Princes Street
Que., H4E 4N9, Canada
Ulverston, Cumbria, LA12 7NQ, UK
Tel: 514-768-8000
Tel: 01 229 581 551
Fax: 514-768-8889
Fax: 01 229 581 554
QF-84
STS-8857
Transmissive Switch Assembly
Features
·
Non contact switching
·
Three wires for electrical connection
·
Fast switching speed
Description
The STS-8857 consists of an infrared emitting diode
and an NPN silicon phototransistor mounted on
opposite sides of a 3.8 mm wide slot. Phototransistor
switching takes place whenever an opaque object
passes through the slot. The polysulfone housing (2)
reduces interference from ambient light and provides
dirt and dust protection. The 40 cm minimum length
wires simplify the connection to the PC board.
Absolute Maximum Ratings
Operating & Storage Temperature
-40
°
C to +85
°
C
Input Diode
Reverse Voltage
3 V
Continuous Forward Current
50 mA
Peak Forward Current (1
µ
s pulse)
3 A
Power Dissipation (1)
100 mW
Phototransistor
Collector-Emitter Voltage
30 V
Emitter-Collector Voltage
5 V
Power Dissipation (1)
100 mW
Dimensions in mm. (-/+ 0.12)
Wires are omitted
for clarity
15.5
3.8
18.3
18.3
3.3
9.0
11.7
Optical center-line
3.4
Wire
7.6
3.8
14.5
6.3
Red
Brown
Black
Schematic
Notes:
(1) Derate linearly 1.33 mW/
°
C above 25
°
C.
(2) Plastic housing is soluble in chlorinated
hydrocarbons and ketones. Recommended
cleaning agents are methanol or isopropanol.
Electrical Characteristics
(T
A
=25
°
C unless otherwise noted)
Symbol
Parameter
Min Typ Max
Units
Test Conditions
Input Diode
V
F
Forward Voltage
1.2
1.7
V
I
F
= 20 mA
I
R
Reverse Current
10
µ
A
V
R
= 3 V
Output Phototransistor
I
CEO
Collector Dark Current
100
nA
V
CE
=10V, Ee=0
BV
CEO
Collector-Emitter Breakdown Voltage
30
V
I
C
=100
µ
A, Ee=0
BV
ECO
Emitter-Collector Breakdown Voltage
5
V
I
C
=100
µ
A, Ee=0
Coupled
V
CE(SAT)
Collector Emitter Saturation Voltage
0.4
V
I
C
=100
µ
A, I
F
= 20 mA
I
C(ON)
On-State Collector Current
1.5
mA
V
CE
=10V, I
F
= 20 mA
Specifications subject to change without notice
103057 REV 1
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