TLH11725

November 1992

TP3406

DASL Digital Adapter for Subscriber Loops

General Description

The TP3406 is a complete monolithic transceiver for data

transmission on twisted pair subscriber loops It is built on

National’s double poly microCMOS process and requires

line coding in which binary ‘1’s are alternately transmitted

as a positive pulse then a negative pulse is used to ensure

low error rates in the presence of noise with lower emi radia-

tion than other codes such as Bi-phase (Manchester)

Full-duplex transmission at 144 kbs is achieved on a single

twisted wire pair using a burst-mode technique (Time Com-

pression Multiplexed) Thus the device operates as an ISDN

‘U’ Interface for short loop applications typically in a PBX

environment providing transmission for 2 B channels and 1

D channel On

24 cable the range is up to 800 meters

System timing is based on a MasterSlave configuration

with the line card end being the Master which controls loop

timing and synchronisation All timing sequences necessary

for loop activation and de-activation are generated on-chip

Selection of Master and Slave mode operation is pro-

grammed via the Microwire Control Interface

A 2048 MHz clock which may be synchronized to the sys-

tem clock controls all transmission-related timing functions

Features

Complete ISDN PBX 2-Wire Data Transceiver including

Y

2 B plus D channel interface for PBX U Interface

Y

144 kbs full-duplex on 1 twisted pair using Burst Mode

Y

Loop range up to 800 meters ( 24AWG)

Y

Alternate Mark Inversion coding with transmit filter and

scrambler for low emi radiation

Y

Adaptive line equalizer

Y

On-chip timing recovery no external components

Y

Standard TDM interface for B channels

Y

Separate interface for D channel

Y

2048 MHz master clock

Y

Driver for line transformer

Y

4 loop-back test modes

Y

Y

Y

Applications in

PBX Line Cards

Terminals

Regenerators

Y

Available in 28-pin PLCC Package

Block Diagram

TLH11725 – 1

TRI-STATE

is a registered trademark of National Semiconductor Corporation

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A