TP3404

4 COMPLETE ISDN PBX 2-WIRE DATA TRANSCEIVERS INCLUDING:
`Quad 2 B plus D channel interface for PBX ``U'' interface
`144 kb/s full-duplex on 1 twisted pair using Burst Mode Transmission Technique
`Loop range up to 6 kft (24AWG)
`Alternate Mark Inversion coding with transmit Pulse Shaping DAC, Smoothing Filter, and scrambler for low emi radiation
`Adaptive line equalizer
`On-chip timing recovery, no external components
`Programmable Time-Slot Assignment TDM interface for B channels
`Separate interface for D channel with Programmable Sub-Slot Assignment
`4.096 MHz master clock
`4 loop-back test modes
`MICROWIRE<sup>TM</sup> compatible serial control interface
`5V operation
`28-pin PLCC package

The TP3404 is a combination 4-line transceiver for voice and data transmission on twisted pair subscriber loops, typically in PBX line card applications. TP3404 is a companion device to the TP3401/2/3 DASL single-channel transceivers. In addition to 4 independent transceivers, a time-slot assignment circuit is included to support interfacing to the system backplane.

Each QDASL line of TP3404 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.Full-duplex transmission at 144 kb/s is achieved on single twisted wire pairs using a burst-mode technique (Time Compression Multiplexed). All timing sequences necessary for loop activation and de-activation are generated on-chip.

Alternate Mark Inversion (AMI) line coding of TP3404 is used to ensure low error rates in the presence of noise with lower emi radiation than other codes such as Biphase (Manchester). On 24 AWG cable the range is at least 1.8 km (6k ft).