TP3404 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Quad Digital Adapter for Subscriber Loops (QDASL)

PRELIMINARY
July 1994
TP3404
Quad Digital Adapter for Subscriber Loops (QDASL)
General Description
The TP3404 is a combination 4-line transceiver for voice
and data transmission on twisted pair subscriber loops typi-
cally in PBX line card applications It is a companion device
to the TP3401 2 3 DASL single-channel transceivers In
addition to 4 independent transceivers a time-slot assign-
ment circuit is included to support interfacing to the system
backplane
Each QDASL line operates as an ISDN ‘‘U’’ Interface for
short loop applications typically in a PBX environment pro-
viding transmission for 2 B channels and 1 D channel
Full-duplex transmission at 144 kb s is achieved on single
twisted wire pairs using a burst-mode technique (Time Com-
pression Multiplexed) All timing sequences necessary for
loop activation and de-activation are generated on-chip
Alternate Mark Inversion (AMI) line coding is used to ensure
low error rates in the presence of noise with lower emi radia-
tion than other codes such as Biphase (Manchester) On
24 AWG cable the range is at least 1 8 km (6k ft)
Features
4 COMPLETE ISDN PBX 2-WIRE DATA TRANSCEIVERS
INCLUDING
Y _{Quad 2 B plus D channel interface for PBX ‘‘U’’}
interface
Y _{144 kb s full-duplex on 1 twisted pair using Burst Mode}
Transmission Technique
Y _{Loop range up to 6 kft ( 24AWG)}
Y _{Alternate Mark Inversion coding with transmit Pulse}
Shaping DAC Smoothing Filter and scrambler for low
emi radiation
Y _{Adaptive line equalizer}
Y _{On-chip timing recovery no external components}
Y _{Programmable Time-Slot Assignment TDM interface for}
B channels
Y _{Separate interface for D channel with Programmable}
Sub-Slot Assignment
Y _{4 096 MHz master clock}
Y _{4 loop-back test modes}
Y _MICROWIRETM _{compatible serial control interface}
Y _{5V operation}
Y _{28-pin PLCC package}
Block Diagram
TRI-STATE is a registered trademark of National Semiconductor Corporation
MICROWIRETM is a trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation TL H 11924
TL H 11924 – 1
RRD-B30M115 Printed in U S A