V23818-K15-B57 Datasheet, PDF (5/18 Pages) Infineon Technologies AG – SFP - Small Form-factor Pluggable Single Mode 1300 nm 1.0625 Gbit/s Fibre Channel 1.25 Gigabit Ethernet Transceiver with LC™ Connector

V23818-K15-B57
Description
Functional Description of SFP Transceiver
This transceiver is designed to transmit serial data via single mode cable.
Tx Fault
TxDis
TD−
TD+
Automatic
Shut-Down
LEN
Laser
Driver
Tx Coupling Unit
e/o
Laser
RD−
RD+
LOS
MOD-DEF
Power
Control
Monitor
Receiver
EEPROM
o/e
Single Mode Fiber
Rx Coupling Unit
o/e
File: 1353
Figure 2 Functional Diagram
The receiver component converts the optical serial data into LVPECL compatible
electrical data (RD+ and RD–). The Loss Of Signal (LOS) shows whether an optical
signal is not present (lost).
The transmitter converts LVPECL compatible electrical serial data (TD+ and TD–) into
optical serial data. Data lines are differentially 100 Ω terminated.
The transmitter contains a laser driver circuit that drives the modulation and bias current
of the laser diode. The currents are controlled by a power control circuit to guarantee
constant output power of the laser over temperature and aging. The power control uses
the output of the monitor PIN diode (mechanically built into the laser coupling unit) as a
controlling signal, to prevent the laser power from exceeding the operating limits.
Single fault condition is ensured by means of an integrated automatic shutdown circuit
that disables the laser when it detects laser fault to guarantee the laser Eye Safety.
The transceiver contains a supervisory circuit to control the power supply. This circuit
makes an internal reset signal whenever the supply voltage drops below the reset
threshold. It keeps the reset signal active for at least 140 milliseconds after the voltage
has risen above the reset threshold. During this time the laser is inactive.
Data Sheet
5
2003-04-25