GENERAL DESCRIPTION
The XRT59L91 is an optimized single-chip analog 3.3V E1 line interface unit (LIU) fabricated using low power CMOS technology. The LIU IC consists of both a Transmitter and a Receiver function. The Transmitter accepts a TTL or CMOS level signal from the Terminal Equipment; and outputs this data to the line via bipolar pulses that are compliant to the ITU-T G.703 pulse template for E1. The Receiver accepts an attenuated bipolar line signal (from the remote terminal equipment) and outputs this data to the (near-end) terminal equipment via CMOS level signals.
The receiver input can be transformer or capacitively coupled to the line. The receiver input is transformer coupled to the line, using the 2:1 step-down transformer. The transmitter is coupled to the line using a 1:2 step-up transformer. This same configuration is applicable for both balanced (120W ) and unbalanced (75W ) interfaces.

FEATURES
• Complete E1 (CEPT) line interface unit
   (Transmitter and Receiver)
• Generates transmit output pulses that are compliant with the ITU-T G.703 Pulse Template for 2.048Mbps (E1) rates
• On-Chip Pulse Shaping for both 75W and 120W Line Drivers
• Receiver can either be transformer or capacitively-coupled to the line
• Detects and Clears LOS (Loss of Signal) per ITU-T G.775
• Compliant with the ITU-T G.823 Jitter Tolerance Requirements
• Compliant with the ITU-T G.703 EOS Over voltage protection requirements
• Supports both Local- and Remote-Loop back Operations
• Logic Inputs accept either 3.3V or 5.0V levels
• Operates over the Industrial Temperature Range
• Ultra Low Power Dissipation
• +3.3V Supply Operation

APPLICATIONS
• PDH Multiplexers
• SDH Multiplexers
• Digital Cross-Connect Systems
• DECT (Digital European Cordless Telephone)
   Base Stations
• CSU/DSU Equipment.
• Test Equipment