TP3420A

TP3420A ISDN S/T Interface Device PRELIMINARY July 1994 TP3420A ISDN S/T Interface Device General Description The TP3420A is an enhanced version of the TP3420, with a number of upgraded features for compliance with the new release of ANSI T1.605-1991 and CCITT I-430. At initial power-up the device is fully backwards compatible with the TP3420 device, and modifications to the firmware are only required to take advantage of the new features. The TP3420A S Interface Device (SID™) is a complete monolithic transceiver for data transmission on twisted pair subscriber loops. It is built on National’s advanced 1.0 micron double-metal CMOS process, and requires only a single +5V supply. All functions specified in CCITT recommendation I.430 (1991) and ANSI T1.605 (1991) for ISDN basic access at the “S” and “T” interfaces are provided, and the device can be configured to operate either in a TE (Terminal Equipment), in an NT-1 or NT-2 (Network Termination) or as a PABX line-card or trunk-card device. As specified in I.430, full-duplex transmission at 192 kb/s is provided on separate transmit and receive twisted wire pairs using inverted Alternate Mark Inversion (AMI) line coding. 2 “B” channels, each of 64 kb/s, and 1 “D” channel at 16 kb/s are available for users’ data. In addition, the TP3420A provides the 800 b/s “S1”, “S2” & “Q” multiframe channels for Layer 1 maintenance. All I.430 wiring configurations are supported by the TP3420A SID, including the “passive bus” for up to 8 TE’s...