ETC HFD3031-002

HFD3031
Schmitt Input, Inverting TTL Output Receiver
FEATURES
• Converts fiber optic input signals to TTL totem pole
outputs
•
Sensitivity is 1.5 µW peak (-28.2 dBm)
•
Single 5 V supply requirement
•
Schmitt circuitry gives 17 dB dynamic range and
low Pulse Width Distortion
•
Operates up to 200K bps NRZ
•
Plastic TO-18 style cap
•
Designed to operate with Honeywell 850 nm LEDs
and integrated transmitters
FIBER106.TIF
DESCRIPTION
The HFD3031 is a sensitive Schmitt optical receiver
designed for use in short distance, 850 nm fiber optic
systems. It uses a bipolar integrated receiver circuit with
internal voltage regulation and internal photodiode. The
TTL inverting output allows the HFD3031 to be directly
interfaced with standard digital TTL circuits. The plastic
package with a TO-18 collar can be mounted in several
types of fiber optic connectors.
APPLICATION
The HFD3031 fiber optic receiver converts the optical
signal in a point to point data communications fiber optic
link to a TTL output. It is designed to be mounted in a
fiber optic connector that aligns the optical axis of the
component to the axis of the optical fiber. Its photodiode
is mechanically centered within the TO-18 package.
Electrical isolation is important in obtaining the maximum
performance of this high sensitivity receiver. Shielding
can reduce coupled noise and obtain maximum
sensitivity. This can include the use of ground planes in
the PCB, shielding around the device, and shielding
around the leads. An internal voltage regulator allows
operation with a 5 volt supply. An external bypass
capacitor (0.1 µF) between VÙÙ (pin 1) and ground (pin 3)
is recommended for maximum power supply noise
rejection.
Honeywell also offers companion transmitters designed
to operate in conjunction with the HFD3031.
Honeywell reserves the right to make
changes in order to improve design and
supply the best products possible.
OUTLINE DIMENSIONS in inches (mm)
WINDOW
.047 (1.19) DIA.
CRUSH RING
.229 (5.82)
.220 (5.59)
.210 (5.33)
.081 (2.06)
.176 (4.47)
.165 (4.19)
.500 MIN
(12.7)
1
3
2
FIBER202.DIM
Pinout
1. VÙÙ
2. Output (TTL)
3. Case (ground)
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285
HFD3031
Schmitt Input, Inverting TTL Output Receiver
APPLICATION (continued)
Optical power (photons) from the fiber strikes the
photodiode and is converted to electrical current which
is then converted into voltage in the transimpedance
preamplifier. The comparator stage incorporates the
Schmitt trigger circuitry which ensures proper output
signals. The Schmitt detection circuit monitors the input
preamplifier, and triggers when its output exceeds
preset levels. These levels are established sufficiently
above the worst case RMS noise level to allow an
excellent BER (bit error rate), while low enought to give
enough sensitivity to permit operation over long links.
This circuitry recognizes the positive and negative going
input signals. When optical input goes from high to low,
electrical output changes to "1" (high). The output
changes to "0" (low) when optical input goes from low to
high. Limited bandwidth minimizes noise problems. The
Schmitt trigger detector stage output is designed to
ensure good pulse width distortion (PWD).
286
h
Honeywell reserves the right to make
changes in order to improve design and
supply the best products possible.
HFD3031
Schmitt Input, Inverting TTL Output Receiver
ELECTRO-OPTICAL CHARACTERISTICS (VÙÙ = 5 VDC unless otherwise stated)
PARAMETER
SYMBOL
Input Sensitivity [À]
MIN
PÛÜ
(peak)
High Level Logic Output Voltage
Low Level Logic Output Voltage
VÏÝ
VÏÚ
Rise Time
Fall Time
Supply Current
Pulse Width Distortion [À]
tß
t¸
IÙÙ
PWD
2.4
TYP
MAX
UNITS
TEST CONDITIONS
0.5
1.5
µW
3.3
0.3
0.4
V
V
æÎ = 850 nm into 100/140
micron fiber cable, Duty
cycle = 50%, square wave
PÛÜ – 0.1 µW, VÙÙ = 5.0 VDC
PÛÜ — 1.5 µW, VÙÙ = 5.0 VDC
IÏ – 16 mA
PÛÜ – 0.1 µW, VÏ = 0.4 to 2.4 V
PÛÜ — 1.5 µW, VÏ = 2.4 to 0.4 V
VÙÙ = 5 VDC
f = 20 kHz, Duty Cycle = 50%
PÛÜ = 1.5 µW
PÛÜ = 100 µW
PÛÜ —1.0µW, Duty Cycle = 50%
12
3
6
5
5
Bandwidth
Output Impedance
BW
IÞ
12
10
10
200
20
ns
ns
mA
%
kHz
í
Notes
1. TÙ = +25¡C
ABSOLUTE MAXIMUM RATINGS
(25¡C Free-Air Temperature unless otherwise noted)
Storage temperature
-40 to 85¡C
RECOMMENDED OPERATING CONDITIONS
Operating temperature
0 to +85¡C
(heat sinked)
Operating temperature
-40 to +85¡C
Supply voltage
+4.5 to +7 V
Lead solder temperature
260¡C, 10 s
Optical input power
1.5 to 100 µW
Junction temperature
150¡C
Optical signal pulse width
> 4 µs
Supply voltage
+7 V
Stresses greater than those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at these or
any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect
reliability.
Honeywell reserves the right to make
changes in order to improve design and
supply the best products possible.
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287
HFD3031
Schmitt Input, Inverting TTL Output Receiver
ORDER GUIDE
Description
Catalog Listing
Standard screening, plastic
package
HFD3031-002
This package is also available in special interface receptacles for
interfacing to standard fiber optic cables.
CAUTION
The inherent design of this component causes
it to be sensitive to electrostatic discharge
(ESD). To prevent ESD-induced damage
and/or degradation to equipment, take normal
ESD precautions when handling this product.
BLOCK DIAGRAM
FIBER INTERFACE
Honeywell detectors are designed to interface with
multimode fibers with sizes (core/cladding diameters)
ranging from 50/125 to 200/230 microns. Honeywell
performs final tests using 100/140 micron core fiber. The
fiber chosen by the end user will depend upon a number
of application issues (distance, link budget, cable
attenuation, splice attenuation, and safety margin). The
50/125 and 62.5/125 micron fibers have the advantages
of high bandwidth and low cost, making them ideal for
higher bandwidth installations. The use of 100/140 and
200/230 micron core fibers results in greater power being
coupled by the transmitter, making it easier to splice or
connect in bulkhead areas. Optical cables can be
purchased from a number of sources.
SWITCHING WAVEFORM
FIBER003.SCH
Fig. 1
Pulse Width Distortion vs Temperature
FIBER202.CIR
Fig. 2
Pulse Width Distortion vs Frequency
FIBER038.GRA
288
h
FIBER039.GR
Honeywell reserves the right to make
changes in order to improve design and
supply the best products possible.
HFD3031
Schmitt Input, Inverting TTL Output Receiver
Fig. 3
Pulse Width Distortion vs Optical Input
Power
Fig. 4
Propagation Delay vs Optical Input Power
FIBER041.GR
FIBER040.GRA
Honeywell reserves the right to make
changes in order to improve design and
supply the best products possible.
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