TWO CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
The XRT73L02M is a two-channel fully integrated
Line Interface Unit (LIU) for E3/DS3/STS-1 applica-
tions. It incorporates independent Receivers, Trans-
mitters in a single 100 pin TQFP package.
The XRT73L02M can be configured to operate in ei-
ther E3 (34.368 MHz), DS3 (44.736 MHz) or STS-1
(51.84 MHz) modes.The transmitter can be turned off
or tri-stated for redundancy support and for conserv-
The XRT73L02M’s differential receiver provides high
noise interference margin and is able to receive the
data over 1000 feet of cable or with up to 12 dB of ca-
The XRT73L02M provides both Serial Microproces-
sor Interface as well as Hardware mode for program-
ming and control.
The XRT73L02M supports local,remote and digital
loop-backs. The XRT73L02M also contains an on-
board Pseudo Random Binary Sequence (PRBS)
generator and detector with the ability to insert and
detect single bit error.
• On chip Clock and Data Recovery circuit for high
input jitter tolerance.
• Meets the jitter tolerance requirements as specified
in ITU-T G.823_1993 for E3 and Telcordia GR-499-
CORE for DS3 applications.
• 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
either be enabled or disabled.
• On-chip clock synthesizer generates the appropri-
ate rate clock from a single frequency XTAL.
• Provides low jitter clock outputs for either DS3,E3
or STS-1 rates.
• On-chip clock synthesizer provides the appropriate
rate clock from a single 12.288 MHz Clock.
• Provides low jitter output clock.
• Compliant with Bellcore GR-499, GR-253 and ANSI
T1.102 Specification for transmit pulse
• Tri-state Transmit output capability for redundancy
• Transmitter can be turned on or off.
CONTROL AND DIAGNOSTICS:
• 5 wire Serial Microprocessor Interface for control
• Supports optional internal Transmit Driver Monitor-
• 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 100 pin TQFP.
• -40°C to 85°C Industrial Temperature Range.
• E3/DS3 Access Equipment.
• STS1-SPE to DS3 Mapper.
• Digital Cross Connect Systems.
• CSU/DSU Equipment.
• Fiber Optic Terminals.
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com