V23818-K305-L57 Infineon Technologies, V23818-K305-L57 Datasheet - Page 5

• Manufacturer Part Number: V23818-K305-L57
• Description: TXRX ETHRNET MULT-MODE 1.25GBIT
• Manufacturer: Infineon Technologies

Specifications of V23818-K305-L57

• Data Rate: 1.25Gbps
• Wavelength: 850nm
• Applications: Ethernet
• Voltage - Supply: 3.1 V ~ 3.5 V
• Connector Type: LC Duplex
• Mounting Type: PCB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: V23818-K305-L57IN

APPLICATION NOTES
Small Form Factor Pinning Comparison
The drawing below gives you a comparison between the differ-
ent pinnings 2x5, 2x6, 2x10. Dimension for diameter and dis-
tance of additional pins is similar to the existing dimensions of
the other pins.
Pin Description
RS pin
The RS Rate Select: is not connected.
LF pin
The LF pin (Laser Fault) is a TTL output of the Laser Driver
Supervisor Circuit. A Logic “1” level can be measured in case
of a laser fault. It will not show a fault if the laser is being dis-
abled using the TxDis input, since this is not a fault condition.
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.
Fiber Optics
to V
CC
and 125
resistor at each (D, Dn). In DC coupled
RX VCC 2
RX VEE 1
RXD + 5
to V
RXD - 4
SD 3
EE
to V
at Data and Datanot. Please con-
CC
and 82
resistance can be achieved
RX VCC 3
RX VEE 2
RXD + 6
RXD - 5
should be placed at the
RS 1
SD 4
to V
EE
RX CLK + 5
RX CLK - 4
VCC PIN 1
, for 5 V:
RX VCC 7
RX VEE 2
RX VEE 3
RX VEE 6
RXD + 10
RXD - 9
SD 8
V23818-K305-L17/L57 , SFF , MM 850nm 1.0625GBd Fibre Channel, 1.25GBE 2x5 Trx (LC™)
RX
TOP VIEW
2 x 10
2 x 6
2 x 5
5
TX
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.
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.
A recommendation is to connect the housing leads to signal
GND. However, in certain applications it may improve EMI per-
formance by connecting them to chassis GND.
The cutout should be sized so that all contact springs make
good contact with the face plate.
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.
Transceiver Pitch
Dimensions in (mm) inches
20 P MON +
19 P MON -
18 BIAS MON +
17 BIAS MON -
16 TX VEE
15 TXD -
14 TXD +
13 TX DIS
12 TX VEE
11 TX VCC
r
of 4, the wavelength of the harmonics inside the
*) min. pitch between SFF transceiver according to MSA.
12 LASER FAULT
11 TXD -
10 TXD +
9 TX DIS
8 TX VEE
7 TX VCC
(13.97)
.550
10 TXD -
9 TXD +
8 TX DIS
7 TX VEE
6 TX VCC
*)