Fiber Optics
V23806-A84-C3, Single Mode 155 MBd ATM/SDH/SONET 1x9 Trx, Ext. Temp. Range
2
DESCRIPTION
The Infineon single mode ATM transceiver complies with the
ATM Forum
’
s
Network Compatible ATM for Local Network
Applications
document and ANSI
’
s
Broadband ISDN -
Customer Installation Interfaces,
Physical Media Dependent
Specification
, T1.646-1995, Bellcore-SONET OC-3/IR-1 and
ITU-T G.957 STM-1/S.1.1.
ATM was developed to facilitate solutions in multimedia appli-
cations and real time transmission. The data rate is scalable,
and the ATM protocol is the basis of the broadband public net-
works being standardized in the International Telecommunica-
tions Union (ITU), the former International Telegraph and
Telephone Consultative Committee (CCITT). ATM can also be
used in local private applications.
This Infineon single mode ATM transceiver is a single unit com-
prised of a transmitter, a receiver, and an SC receptacle. This
design frees the customer from many alignment and PC board
layout concerns. The module is designed for low cost WAN
applications. It can be used as the network end device interface
in workstations, servers, and storage devices, and in a broad
range of network devices such as bridges, routers, and intelli-
gent hubs, and wide area ATM switches.
This transceiver operates at 155.52 Mbit/s from a single power
supply (+5 V). The differential data inputs, data outputs and sig-
nal detect output are PECL compatible.
Functional Description
This transceiver is designed to transmit serial data via single
mode cable.
Functional Diagram
The receiver component converts the optical serial data into
PECL compatible electrical data (RD and RDnot). The Signal
Detect (SD, active high) shows whether optical data is
present
(1)
.
The transmitter converts electrical PECL compatible serial data
(TD and TDnot) into optical serial data. It 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.
This module is a Class 1 laser product, due to an integrated
automatic shutdown circuit that disables the laser when it
detects transmitter failures.
The transceiver contains a supervisory circuit to monitor the
power supply. This circuit makes an internal reset signal when-
ever 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.
Note
1. We recommend to switch off the transmitter supply (V
CC
-Tx) if no
transmitter input data is applied.
Automatic
Shut-Down
Laser
Driver
Power
Control
Receiver
o/e
o/e
Laser
e/o
RX Coupling Unit
TD
TD
RD
RD
SD
Laser Coupling Unit
Single Mode Fiber
LEN
Monitor