TP3403V/NOPB

Digital Adapter 28Pin PLCC Tube

The TP3401, TP3402 and TP3403 are complete monolithic transceivers for data transmission on twisted pair subscriber loops. They are built on National’s double poly microCMOS process, and require only a single a5 Volt supply. Alternate Mark Inversion AMI 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 radiation than other codes such as Bi- phase Manchester.

Full-duplex transmission at 144 kb/s 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 at least 1.8 km 6k ft.

System timing is based on a Master/Slave 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 2.048 MHz clock, which may be synchronized to the sys- tem clock, controls all transmission-related timing functions.

For the TP3401, this clock must be provided from an exter- nal source; the TP3402 includes an oscillator circuit requir- ing an external crystal. The TP3403 includes the functions of both the TP3401 and the TP3402.