XRT75L04

The XRT75L04 is a Four-Channel fully integrated Line Interface Unit (LIU) and Jitter Attenuator for E3/DS3/STS-1 applications. It incorporates four independent Receivers, Transmitters and Jitter Attenuators in a single 176 pin TQFP package.

Each channel of the XRT75L04 can be independently configured to operate in E3 (34.368 MHz), DS3 (44.736 MHz) or STS-1 (51.84 MHz) rates. Each transmitter can be turned off and tri-stated for redundancy support and power conservation. The XRT75L04’s differential receivers provide high noise interference margin and are able to receive the data over 1000 feet of cable, or with cable attenuation of up to 12 dB.

The XRT75L04 incorporates an advanced crystal-less jitter attenuator per channel that can be selected either in the transmit or receive path. The jitter attenuator performance meets the ETSI TBR-24 and Bellcore GR-499 specifications. The XRT75L04 provides both Serial Microprocessor Interface as well as a Hardware mode for programming and control.

The XRT75L04 supports local, remote and digital loop-backs. The XRT75L04 also contains an on-board Pseudo Random Binary Sequence (PRBS) generator and detector with the ability to insert and detect single bit error.

Receiver:

• On chip Clock and Data Recovery circuit for high input jitter tolerance
• Meets E3/DS3/STS-1 Jitter Tolerance Requirements
• Detects and Clears LOS as per G.775
• Receiver Monitor mode handles up to 20 dB flat loss with 6 dB cable attenuation
• On chip B3ZS/HDB3 encoder and decoder that can be either enabled or disabled
• On-chip Clock Synthesizer generates the appropriate rate clock from a single frequency Crystal
• Provides low jitter clock outputs for either E3, DS3 or STS-1 rates
• Meets Jitter Tolerance Requirements, as specified in ITU-T G.823_1993 for E3 Applications
• Meets Jitter Tolerance Requirements, as specified in Bellcore GR-499-CORE for DS3 Applications

• Compliant with Bellcore GR-499, GR-253 and ANSI T1.102 Specification for transmit pulse
• Tri-state Transmit output capability for redundancy applications
• Transmitter can be turned on or off Jitter Attenuator:
• On chip advanced crystal-less Jitter Attenuator
• Jitter Attenuators can be selected in Receive or Transmit paths
• Compliant with jitter transfer template outlined in ITU G.751, G.752, G.755, GR-253 and GR-499-CORE,1995 standards
• Meets ETSI TBR 24 Jitter Transfer Requirements
• 16 or 32 bits selectable FIFO size
• Meets the Jitter and Wander specifications described in ANSI T1.105.03b
• Jitter Attenuators can be disabled

• 5 wire Serial Microprocessor Interface for control and configuration
• Supports optional internal Transmit Driver Monitoring
• PRBS Error Counter Register to accumulate errors
• Hardware Mode for control and configuration
• Supports Local, Remote and Digital Loop-backs
• Single 3.3 V ± 5% power supply
• 5 V Tolerant I/O
• Available in 176 pin TQFP
• -40°C to 85°C Industrial Temperature Range
• Pb-Free, RoHS Compliant Versions Offered

• E3/DS3 Access Equipment
• STS1-SPE to DS3 Mapper
• DSLAMs
• Digital Cross Connect Systems
• CSU/DSU Equipment
• Routers
• Fiber Optic Terminals