V23818-K305-B57 Infineon Technologies, V23818-K305-B57 Datasheet - Page 6

• Manufacturer Part Number: V23818-K305-B57
• Description: TXRX ETHRNET MULT-MODE 1.25GBIT
• Manufacturer: Infineon Technologies
• Series: -r

Specifications of V23818-K305-B57

• Data Rate: 1.25Gbps
• Wavelength: 850nm
• Applications: Ethernet
• Voltage - Supply: 3.1 V ~ 3.5 V
• Connector Type: LC Duplex
• Mounting Type: SFP
• Lead Free Status / Rohs Status: Contains lead / RoHS non-compliant
• Other names: V23818-K305-B57IN

APPLICATION NOTES
EMI-Recommendation
To avoid electromagnetic radiation exceeding the required limits
please take note of the following recommendations.
When Gigabit switching components are found on a PCB (multi-
plexers, clock recoveries etc.) any opening of the chassis may
produce radiation also at chassis slots other than that of the
device itself. Thus every mechanical opening or aperture should
be as small as possible.
On the board itself every data connection should be an imped-
ance matched line (e.g. strip line, coplanar strip line). Data,
Datanot should be routed symmetrically, vias should be
avoided. A terminating resistor of 100
end of each matched line. An alternative termination can be
provided with a 50
systems a thevenin equivalent 50
as follows: For 3.3 V: 125
82
sider whether there is an internal termination inside an IC or a
transceiver.
In certain cases signal GND is the most harmful source of radia-
tion. Connecting chassis GND and signal GND at the plate/
bezel/ chassis rear e.g. by means of a fiber optic transceiver
may result in a large amount of radiation. Even a capacitive cou-
pling between signal GND and chassis may be harmful if it is
too close to an opening or an aperture.
If a separation of signal GND and chassis GND is not possible,
it is strongly recommended to provide a proper contact
between signal GND and chassis GND at every location where
possible. This concept is designed to avoid hotspots. Hotspots
are places of highest radiation which could be generated if only
a few connections between signal and chassis GND exist.
Compensation currents would concentrate at these connec-
tions, causing radiation.
Fiber Optics
to V
CC
and 125
resistor at each (D, Dn). In DC coupled
to V
EE
to V
at Data and Datanot. Please con-
CC
and 82
resistance can be achieved
should be placed at the
to V
EE
, for 5 V:
6
By use of Gigabit switching components in a design, the return
path of the RF current must also be considered. Thus a split
GND plane of Tx and Rx portion may result in severe EMI prob-
lems.
The cutout should be sized so that all contact springs make
good contact with the face plate.
For the SFP transceiver a connection of the SFP cage pins to
chassis GND is recommended. If no separate chassis GND is
available on the users PCB the pins should be connected to sig-
nal GND. In this case take care of the notes above.
Please consider that the PCB may behave like a waveguide.
With an
PCB will be half of that in free space. In this scenario even the
smallest PCBs may have unexpected resonances.
The SFP transceiver can be assembled onto the host board
together with all cages and host board connectors complying
with the SFP multi source agreement.
Infineon Proposes
Cage:
Infineon Technologies
Part Number: V23818-S5-N1
V23818-K305-B57 , SFP MM 850nm 1.0625GBd Fibre Channel 1.25GBE Trx (LC™)
r
SFP
of 4, the wavelength of the harmonics inside the
Cage
Host board connector:
Tyco Electronics
Part Number: 1367073-1
Host board
connector