HFBR-5111 Agilent(Hewlett-Packard), HFBR-5111 Datasheet - Page 5

• Manufacturer Part Number: HFBR-5111
• Description: Low Cost/ Industry Standard FDDI MIC Transceivers
• Manufacturer: Agilent(Hewlett-Packard)

Figure 4. Optical Power Budget at
BOL vs. Fiber Optic Cable Length.
96
standing and design trade-offs
associated with this transceiver.
You can contact them through
your Hewlett-Packard sales
representative.
The following information is
provided to answer some of the
most common questions about
the use of these parts.
Transceiver Optical Power
Budget versus Link Length
The Optical Power Budget (OPB)
is the available optical power for
a fiber-optic link to accommodate
fiber cable losses plus losses due
to in-line connectors, splices,
optical switches, and to provide
margin for link aging and
unplanned losses due to cable
plant reconfiguration or repair.
Figure 4 illustrates the predicted
OPB associated with the trans-
ceivers specified in this data
sheet at the Beginning of Life
(BOL). This curve represents the
attenuation and chromatic plus
modal dispersion losses
associated with the 62.5/125 m
and 50/125 m fiber cables only.
The area under the curve
represents the remaining OPB at
any link length, which is available
for overcoming non-fiber cable
related losses.
14
12
10
8
6
4
2
0
0
FIBER OPTIC CABLE LENGTH – km
0.5
1.0
62.5/125 µm
1.5 2.0 2.5
50/125 µm
3.0
3.5
4.0
Hewlett-Packard LED technology
has produced 1300 nm LED
devices with lower aging charac-
teristics than normally associated
with these technologies in the
industry. The industry convention
is 1.5 dB aging for 1300 nm
LEDs, however HP 1300 nm
LEDs will experience less than 1
dB of aging over normal commer-
cial equipment mission life
periods. Contact your Hewlett-
Packard sales representative for
additional details.
Figure 4 was generated with a
Hewlett-Packard fiber-optic link
model containing the current
industry conventions for fiber
cable specifications and the FDDI
PMD optical parameters. These
parameters are reflected in the
guaranteed performance of the
transceiver specifications in this
data sheet. This same model has
been used extensively in the ANSI
and IEEE committees, including
the ANSI X3T9.5 committee, to
establish the optical performance
requirements for various fiber-
optic interface standards. The
cable parameters used come from
the ISO/IEC JTC1/SC 25/WG3
Generic Cabling for Customer
Premises per DIS 11801
document and the EIA/TIA-568-A
Commercial Building Telecom-
munications Cabling Standard per
SP-2840.
Transceiver Signaling
Operating Rate Range and
BER Performance
For purposes of definition, the
symbol rate (Baud), also called
signaling rate, is the reciprocal of
the symbol time. Data rate (bits/
sec) is the symbol rate divided by
the encoding factor used to
encode the data (symbols/bit).
When used in FDDI 100 Mbps
applications, the performance of
the 1300 nm transceivers is
guaranteed over the signaling
rate of 10 MBd to 125 MBd to the
full conditions listed in the
individual product specification
tables.
The transceivers may be used for
other applications at signaling
rates outside of the 10 MBd to
125 MBd range with some
penalty in the link optical power
budget primarily caused by a
reduction of receiver sensitivity.
Figure 5 gives an indication of
the typical performance of these
1300 nm products at different
rates.
These transceivers can also be
used for applications which
require different bit error rate
(BER) performance. Figure 6
illustrates the typical trade-off
between link BER and the
receiver’s input optical power
level.
Figure 5. Transceiver Relative
Optical Power Budget at Constant
BER vs. Signaling Rate.
CONDITIONS:
1. PRBS 2
2. DATA SAMPLED AT CENTER OF DATA SYMBOL.
3. BER = 10
4. T
5. V
6. INPUT OPTICAL RISE/FALL TIMES = 1.0/2.1 ns.
A
CC
3.0
2.5
2.0
1.5
1.0
0.5
= 25° C
0
= 5 V
0
7
-1
-6
dc
25
50
SIGNAL RATE (MBd)
75 100 125
150
175
200