HFBR-59L1AL Datasheet, PDF (4/16 Pages) Agilent(Hewlett-Packard) – Agilent HFBR-59L1AL 1.25 GBd Ethernet and 1.0625 GBd Fibre Channel 850 nm SFF Low Voltage (3.3 V) Optical Transceiver

Also, Agilent does not
recommend the use of cleaners
that use halogenated
hydrocarbons because of their
potential environmental harm.
Transmitter Section
The transmitter section includes
an 850 nm VCSEL (Vertical
Cavity Surface Emitting Laser)
light source and a transmitter
driver circuit. The driver circuit
maintains a constant optical
power level provided that the
data pattern is valid 8B/10B
code. Connection to the
transmitter is provided via an
LC optical connector.
TX Disable
The HFBR-59L1AL accepts a
LVTTL transmit disable control
signal input which shuts down
the transmitter. A high signal
implements this function while a
low signal allows normal laser
operation. In the event of a fault
(e.g., eye safety circuit
activated), cycling this control
signal resets the module. The
TX Disable control should be
actuated upon initialization of
the module. See Figure 5 for
product timing diagrams.
Eye Safety Circuit
For an optical transmitter
device to be eye-safe in the event
of a single fault failure, the
transmitter will either maintain
normal, eye-safe operation or be
disabled. In the event of an eye
safety fault, the VCSEL will be
disabled.
Receiver Section
Connection to the receiver is
provided via an LC optical
connector. The receiver circuit
also includes a Signal Detect
(SD) circuit which provides an
open collector logic low output
in the absence of a usable input
optical signal level.
3
Signal Detect
The Signal Detect (SD) output
indicates if the optical input
signal to the receiver does not
meet the minimum detectable
level for Fibre Channel
compliant signals. When SD is
low it indicates loss of signal.
When SD is high it indicates
normal operation. The Signal
Detect thresholds are set to
indicate a definite optical fault
has occurred (e.g., disconnected
or broken fiber connection to
receiver, failed transmitter).
Functional Data I/O
Agilent’s HFBR-59L1AL fiber-
optic transceiver is designed to
accept industry standard
differential signals. In order to
reduce the number of passive
components required on the
customer’s board, Agilent has
included the functionality of the
transmitter bias resistors and
coupling capacitors within the
fiber optic module. The
transceiver is compatible with
an “ac-coupled” configuration
and is internally terminated.
Figure 1 depicts the functional
diagram of the HFBR-59L1AL.
Caution should be taken to
account for the proper
interconnection between the
supporting Physical Layer
integrated circuits and the
HFBR-59L1AL. Figure 3
illustrates the recommended
interface circuit.
Reference Designs
Figure 3 depicts a typical
application configuration, while
Figure 4 depicts the
multisourced power supply filter
circuit design.
Regulatory Compliance
See Table 1 for transceiver
Regulatory Compliance
performance. The overall
equipment design will determine
the certification level. The
transceiver performance is
offered as a figure of merit to
assist the designer.
Electrostatic Discharge (ESD)
There are two conditions in
which immunity to ESD damage
is important. Table 1 documents
our immunity to both of these
conditions. The first condition
is during handling of the
transceiver prior to attachment
to the PCB. To protect the
transceiver, it is important to
use normal ESD handling
precautions. These precautions
include using grounded wrist
straps, work benches, and floor
mats in ESD controlled areas.
The ESD sensitivity of the
HFBR-59L1AL is compatible
with typical industry production
environments. The second
condition is static discharges to
the exterior of the host
equipment chassis after
installation. To the extent that
the duplex LC optical interface
is exposed to the outside of the
host equipment chassis, it may
be subject to system-level ESD
requirements. The ESD
performance of the HFBR-
59L1AL exceeds typical industry
standards.
Immunity
Equipment hosting the HFBR-
59L1AL modules will be
subjected to radio-frequency
electromagnetic fields in some
environments. The transceivers
have good immunity to such
fields due to their shielded
design.
Electromagnetic Interference (EMI)
Most equipment designs utilizing
these high-speed transceivers
from Agilent Technologies will
be required to meet the
requirements of FCC in the
United States, CENELEC
EN55022 (CISPR 22) in Europe
and VCCI in Japan. The metal
housing and shielded design of
the HFBR-59L1AL minimize the
EMI challenge facing the host
equipment designer.