The MC145421 has been discontinued. Suggested replacement: MC145423.
The MC145421 and MC145425 UDLTs are high-speed data transceivers
capable of providing 160 kbps full-duplex data communication over 26
AWG and larger twisted-pair cable up to 1 km in length. These devices
are primarily used in digital subscriber voice and data telephone
systems. In addition, the devices meet and exceed the CCITT
recommendations for data transfer rates of ISDNs on a single twisted
pair. The devices utilize a 512 kbaud MDPSK burst modulation
technique to supply the 160 kbps full-duplex data transfer rates. The
160 kbps rate is provided through four channels. There are two B
channels, which are 64 kbps each. In addition, there are two D
channels which are 16 kbps each.
The MC145421 and MC145425 UDLTs are designed for upward
compatibility with the existing MC145422 and MC145426 80 kbps UDLTs,
as well as compatibility with existing and evolving telephone
switching hardware and software architectures.
The MC145421 (Master) UDLT is designed for use at the telephone
switch line card while the MC145425 (Slave) UDLT is designed for use
at the remote digital telset or data terminal.