V23818-C18-L47 Datasheet, PDF (6/17 Pages) Infineon Technologies AG – Small Form Factor Single Mode 1300 nm Multirate up to 155 Mbit/s Transceiver 2x5 Pinning with LC™ Connector

V23818-C18-Lxx/L4xx
Description
Functional Description of SFF 2x5 Pin Row Transceiver
This transceiver is designed to transmit serial data via single mode fiber.
TDis
TD−
TD+
RD−
RD+
SD
Automatic
Shut-Down
Laser
Driver
Power
Control
Limiting
Amp
Tx
Coupling Unit
e/o
Laser
o/e
Monitor
Rx
Coupling Unit
o/e
TIA
Single
Mode
Fiber
File: 1351
Figure 2 Functional Diagram
The receiver component converts the optical serial data into LVPECL compatible
electrical data (RD+ and RD–). The Signal Detect (SD, active high) shows whether an
optical signal is present.
The transmitter converts LVPECL compatible electrical serial data (TD+ and TD–) into
optical serial data.
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 (V_CCt) drops below the reset
threshold (V_TH). 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.
A high signal on TDis enables the transmitter. If TDis is low or not connected the
transmitter is not affected.
Data Sheet
6
2003-06-06