GENERAL DESCRIPTION
The XRT83SL28 is a fully integrated 8-channel E1 short-haul LIU which optimizes system cost and performance by offering key design features. The XRT83SL28 operates from a single 3.3V power supply. The LIU features are programmed through a standard serial microprocessor interface or hardware control. EXAR’s LIU has patented high impedance circuits that allow the transmitter outputs and receiver inputs to be high impedance when experiencing a power failure or when the LIU is powered off. Key design features within the LIU optimize 1:1 or 1+1 redundancy and non-intrusive monitoring applications to ensure reliability without using relays.
Additional features include TAOS for transmit and receive, RLOS, LCV, AIS, DMO, and diagnostic loopback modes.

FEATURES
• Fully integrated 8-Channel short haul transceivers for E1 (2.048MHz) applications.
• Internal Impedance matching on both receive and transmit for 75Ω (E1) or 120Ω (E1) applications.
• Tri-State on a per channel basis for the transmit selection.
• On-Chip transmit short-circuit protection and limiting protects line drivers from damage on a per channel basis.
• Independent Crystal-Less digital jitter attenuators (JA) with 32-Bit or 64-Bit FIFO for the receive or transmit paths
• Driver failure monitor output (DMO) alerts of possible system or external component problems.
• Transmit outputs and receive inputs may be "High" impedance for protection or redundancy applications on a per channel basis.
• Support for automatic protection switching.
• 1:1 and 1+1 protection without relays.
• RLOS/AIS according to ITU-T G.775 or ETSI-300-233.
• On-Chip HDB3 encoder/decoder for each channel.
• On-Chip digital clock recovery circuit for high input jitter tolerance.
• Line code error and bipolar violation detection.
• Transmit all ones (TAOS) for the Transmit and Receive Outputs.
• Supports local analog, remote, and digital loopback modes.
• Supports gapped clocks for mapper/multiplexer applications.
• Low Power dissipation
• Single 3.3V supply operation (3V to 5V I/O tolerant).
• 144-Pin TQFP package
• -40°C to +85°C Temperature Range

APPLICATIONS
• ISDN Primary Rate Interface
• CSU/DSU E1 Interface
• E1 LAN/WAN Routers
• Public Switching Systems and PBX Interfaces
• E1 Multiplexer and Channel Banks
• Integrated Multi-Service Access Platforms (IMAPs)
• Integrated Access Devices (IADs)
• Inverse Multiplexing for ATM (IMA) Wireless Base Stations