Fiber Optics

V23826-C18-C63/C363, Single Mode 155 MBd ATM/SDH/SONET 1x9 Trx (DC/DC)

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—Cus-

tomer Installation Interfaces, Physical Media Dependent Speci-

fication, 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.

The 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, as well as wide area ATM switches.

This transceiver operates at 155.520 Mbit/s from a single power

supply (+5 Volt or 3.3 Volt). The differential data inputs and out-

puts 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

The transmitter converts electrical PECL compatible serial data

(TD and TDnot) into optical serial data.

This version contains an Input Signal Monitor (ISM), that

switches the optical power off if a continuously low level is

applied at Data Input.

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 out-

put 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 transmitter failures. A reset is only possible by turning

the power off, and then on again.

The transceiver contains a supervisory circuit to control the

power supply. This circuit generates an internal reset signal

whenever the supply voltage drops below the reset threshold.

It keeps the reset signal active for at least 15 milliseconds after

the voltage has risen above the reset threshold. During this

time the laser is inactive.

Note

transmitter input data is applied.

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

Signal Monitor and

Automatic Shut-Down

ISM