2
DATA OUT
SINGLE-ENDED
SIGNAL
DETECT OUT
DATA IN
ELECTRICAL SUBASSEMBLY
QUANTIZER IC
DRIVER IC
TOP VIEW
PIN
PHOTODIODE
DUPLEX SC
RECEPTACLE
OPTICAL
SUBASSEMBLIES
LED
PREAMP
IC
DIFFERENTIAL
DIFFERENTIAL
Figure 1. Block Diagram.
These PlN/preamplifier combina-
tions are coupled to a custom
quantizer IC which provides the
final pulse shaping for the logic
output and Signal Detect
function. The data output is
differential. The signal detect
output is single-ended. Both data
and signal detect outputs are
PECL compatible, ECL
referenced (shifted) to a +5 Volt
power supply.
Package
The overall package concept for
the Agilent transceivers consists
of the following basic elements;
two optical subassemblies, an
electrical subassembly, and the
housing with integral duplex SC
connector receptacles. This is
illustrated in Figure 1.
The package outline and pinout
are shown in Figures 2 and 3.
The details of this package
outline and pinout are compliant
with the multisource definition of
the 1x9 SIP. The low profile of
the Agilent transceiver design
complies with the maximum
height allowed for the duplex SC
connector over the entire length
of the package.
The optical subassemblies utilize
a high volume process together
with low cost lens elements which
result in a cost effective
transceiver.
The electrical subassembly con-
sists of a high volume multi-layer
printed circuit board on which
the IC chips and various surface
mount passive circuit elements
are attached.
The package includes internal
shields for the electrical and
optical subassemblies to ensure
low EMI and high immunity to
electromagnetic fields.
The outer housing, including the
duplex SC connector receptacle,
is molded of filled non-conductive
plastic to provide mechanical
strength and electrical isolation.
The solder posts of the Agilent
design are isolated from the
circuit design of the transceiver
and do not require connection to
a ground plane on the circuit
board.
The transceiver is attached to a
printed circuit board with the
nine signal pins and the two
solder posts which exit the
bottom of the housing. The two
solder posts provide the primary
mechanical strength to withstand
the loads imposed on the duplex
or simplex SC connectored fiber
cables.
Application Information
The Application Engineering
group in the Agilent Optical
Communications Division is
available to assist you with the
technical understanding and
design trade-offs associated with
these transceivers. 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
Optical Power Budget (OPB) is
the available optical power for a
fiber optic link to accommodate
fiber cable losses plus losses due
to inline 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 two
transceivers specified in this data
sheet at the Beginning of Life
(BOL). These curves represent
the attenuation and chromatic
plus modal dispersion losses
associated with the 62.5/125
μ
m
and 50/125
μ
m fiber cables only.
The area under the curve repre-
sents the remaining OPB at any
link length, which is available for
overcoming non-fiber cable
related losses.
Agilent LED technology has
produced 800 nm LED and 1300
nm LED devices with lower aging
characteristics than normally