C-13-2500-FDFB-SLC4 Datasheet, PDF (7/10 Pages) Source Photonics, Inc. – 2.5 Gbps Single Mode SFF LC Transceiver

2.5 Gbps Single Mode SFF LC Transceiver
C-1X-2500(C)-FDFB-SLC4
Printed Circuit Board Layout Consideration
A fiber-optic receiver employs a very high gain, wide bandwidth transimpedance amplifier. This amplifier detects and amplifies signals that
are only tens of nA in amplitude when the receiver is operating near its limit. Any unwanted signal currents that couple into the receiver circuitry
causes a decrease in the receiver’s sensitivity and can also degrades the of the receiver’s signal detect (SD) circuit. To minimize the coupling of
unwanted noise into the receiver, careful attention must be given to the printed circuit board.
At a minimum, a double-sided printed circuit board (PCB) with a large component side ground plane beneath the transceiver must be used.
In applications that include many other high speed devices, a multi-layer PCB is highly recommended. This permits the placement of power and
ground on separate layers, which all them to be isolated from the signal lines. Multilayer construction also permits the routing of signal traces
away from high level, high speed signal lines. To minimize the possibility of coupling noise into the receiver section, high level, high speed signals
such as transmitter inputs and clock lines should be routed as far away as possible from the receiver pins.
Noise that couples into the receiver through the power supply pins can also degrade performance. It is recommended that a pi filter in
both the transmitter and receiver power supplies.
EMI and ESC Consideration
LuminentOIC transceivers offer a metalized plastic case and a special chassis grounding clip. As shown in the drawing, this clip connects the
module case to chassis ground then installed flush through the panel cutout. The grounding clip in this way brushes the edge of the cutout in
order to make a proper contact. The use of a grounding clip also provides increased electrostatic protection and helps reduce radiated emissions
from the module or the host circuit board through the chassis faceplate. The attaching posts are at case potential and may be connected to
chassis ground. They should not be connected to circuit ground.
Plastic optical subassemblies are used to further reduce the possibility of radiated emissions by eliminating the metal from the transmitter
and receiver diode housings, which extend into connector space. By providing a non-metal receptacle for the optical cable ferrule, the gigabit
speed RF electrical signal is isolated form the connector area thus preventing radiated energy leakage from these surfaces to the outside of the
panel.
Laser Safety
This single mode transceiver is a Class1 laser product. It complies with IEC 825 and FDA 21 CFR 1040.10 and 1040.11.The transceiver must
be operated within the specified temperature and voltage limits. The optical ports of the module shall determinate with an optical connector or
with a dust plug.
LUMINENTOIC.COM
20550 Nordhoff St. • Chatsworth, CA 91311 • tel: [phone] • fax: [phone]
9F, No 81, Shui Lee Rd. • Hsinchu, Taiwan, R.O.C. • tel: [phone] • fax: [phone]
7
LUMNDS814-Apr2605
rev. A.0