XRT59L921

• Twenty-One (21) Independent E1 (CEPT) Line Interface Units (Transmitter, Receiver, and Recovery)
• Transmit Output Pulses that are Compliant with the ITU-T G.703 Pulse Template Requirement for 2.048Mbps (E1) Rates
• On-Chip Pulse Shaping for both 75 and 120 line drivers
• Detects and Clears LOS (Loss of Signal) Per ITU-T G.775
• Operates over the Industrial Temperature Range
• Ultra Low power consumption
• 3.3V operation with 5V Tolerant Input

The XRT59L921 is an optimized twenty-one channel, E1, line interface unit, fabricated using low power CMOS technology. The device contains twenty-one independent E1 channels. It is primarily targeted towards the SDH multiplexers that accommodate TU12 Tributary Unit Frames. Line cards in these units multiplex 21 E1 channels into higher SDH rates. Devices with 21 E1 interfaces such as the XRT59L921 provide the most efficient method of implementing 63-channel line cards. Each channel performs the driver and receiver functions necessary to convert bipolar signals to logical levels and vice versa.

The receiver input accepts transformer coupled 1:1 signals, while the transmitter is coupled to the line using a 1:2 transformer. The same transformer configuration can be used for both balanced and unbalanced interfaces. The device offers Loss of Signal (LOS) detection, that provides an LOS output indication signal with thresholds and delay that comply with the ITU G.775 requirements.