Data Sheet
1241/1243/1245-Type Uncooled Laser Transmitter
September 1999
Connector Options
Functional Overview (continued)
The standard optical fiber pigtail is 8 µm core single-
mode fiber having a 0.036 in. (914 µm) diameter tight-
buffered outer-jacket. The standard length is 39 in. ±
4 in. (1 m ± 10 cm) and can be terminated with either
an SC or FC-PC optical connector. Other connector
options may be available on special order. Contact your
Agere Account Manager for ordering information.
Since most applications operate at very high data
rates, high-frequency design techniques need to be
used to ensure optimum performance from the trans-
mitter and interfacing circuitry. Input signal paths
should be kept as short and as straight as possible; dif-
ferential signal lines should be equal in length, and
controlled-impedance stripline or microstrip construc-
tion should always be used when laying out the printed-
wiring board traces for the data lines. The Recom-
mended User Interfaces section of this data sheet
shows several methods of interfacing to the transmitter.
Handling Precautions
CAUTION: This device is susceptible to damage as
a result of electrostatic discharge (ESD).
Take proper precautions during both
handling and testing. Follow guidelines
such as JEDEC Publication No. 108-A
(Dec. 1988).
Power Supplies
The transmitter is configured for operation from either a
single +5 V power supply or a single –5 V power sup-
ply. For positive power supply operation, connect Vcc to
the +5 V power supply and connect VEE to ground or
circuit common. For operation from a –5 V power sup-
ply, connect VCC to ground and connect VEE to the –5 V
power supply. Whichever option is chosen, the VCC or
VEE connection to the transmitter should be well filtered
to prevent power supply noise from interfering with
transmitter operation.
Although protection circuitry is designed into the
device, take proper precautions to avoid exposure to
ESD. Agere employs a human-body model (HBM) for
ESD-susceptibility testing and protection-design evalu-
ation. ESD voltage thresholds are dependent on the
critical parameters used to define the model. A stan-
dard HBM (resistance = 1.5 kΩ, capacitance = 100 pF)
is widely used and, therefore, can be used for compari-
son purposes. The HBM ESD withstand voltage estab-
lished for the 1241-/1243-TypeTransmitter is ±1000V.
Transmitter Specifications
Optical Output Power
Transmitter Processing
During manufacture, the optical output power of every
transmitter is tuned to the typical value specified in the
data sheet for that particular transmitter code. The tun-
ing is performed at room ambient and a power supply
voltage of 5 V. The minimum and maximum values
listed in the data sheet for each code group reflect the
worst-case limits that the transmitter is expected to
operate within over its lifetime and over the allowed
power supply and the operating temperature range.
The transmitter can withstand normal wave-soldering
processes. The complete transmitter module is not her-
metically sealed; therefore, it should not be immersed
in or sprayed with any cleaning solution or solvents.
The process cap and fiber pigtail jacket deformation
temperature is 85 °C. Transmitter pins can be wave-
soldered at maximum temperature of 250 °C for
10 seconds.
Every transmitter shipped receives a final test, which
includes a SONET eye-mask test at either the OC-3
(STM-1) data rate of 155.52 Mbits/s, the OC-12 (STM4)
data rate of 622.08 Mbits/s, or the fibre channel FC-0
data rate of 1062.5 Mbits/s. The eye-mask test is
meant to examine the performance of the transmitter's
output optical waveform relative to a minimum data pat-
tern eye opening.
Installation Considerations
Although the transmitter features a robust design, care
should be used during handling. The optical connector
should be kept free from dust, and the process cap
should be kept in place as a dust cover when the
device is not connected to a cable. If contamination is
present on the optical connector, canned air with an
extension tube can be used to remove any debris.
Other cleaning procedures are identified in the techni-
cal note, Cleaning Fiber-Optic Assemblies (TN95-
010LWP).
4
Agere Systems Inc.
AGERE [ AGERE SYSTEMS ]
