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FEBRUARY 2002
XRT7300
E3/DS3/STS-1 LINE INTERFACE UNIT
REV. 1.1.1
GENERAL DESCRIPTION
The XRT7300 DS3/E3/STS-1 Line Interface Unit is
designed to be used in DS3, E3 or SONET STS-1 ap-
plications and consists of a line transmitter and re-
ceiver integrated on a single chip.
XRT7300 can be configured to support the E3
(34.368 Mbps), DS3 (44.736 Mbps) or the SONET
STS-1 (51.84 Mbps) rates.
In the transmit direction, the XRT7300 encodes input
data to either B3ZS (for DS3/STS-1 applications) or
HDB3 (for E3 applications) format and converts the
data into the appropriate pulse shapes for transmis-
sion over coaxial cable via a 1:1 transformer.
In the receive direction the XRT7300 performs equal-
ization on incoming signals, performs Clock Recov-
ery, decodes data from either B3ZS or HDB3 format,
converts the receive data into TTL/CMOS format,
checks for LOS or LOL conditions and detects and
declares the occurrence of line code violations.
The XRT7300 also contains a 4-Wire Microprocessor
Serial Interface for accessing the on-chip Command
registers.
F
IGURE
1. B
LOCK
D
IAGRAM OF THE
XRT7300
E3
STS-1/DS3
Host/(HW)
FEATURES
•
Meets E3/DS3/STS-1 Jitter Tolerance Require-
ments
•
Full Loop-Back Capability
•
Transmit and Receive Power Down Modes
•
Full Redundancy Support
•
Contains a 4-Wire Microprocessor Serial Interface
•
Uses Minimum External components
•
Requires Single +5V Power Supply
•
-40°C to +85°C Operating Temperature Range
•
Available in a 44 pin TQFP package
APPLICATIONS
•
Interfaces to E3, DS3 or SONET STS-1 Networks
•
CSU/DSU Equipment
•
PCM Test Equipment
•
Fiber Optic Terminals
•
Multiplexers
N
OTE
:
This Device is Protected by US Patent # 6,157,270
RLOL EXCLK
ICT
RCLK2INV
RTIP
RRING
REQDIS
AGC/
Equalizer
Peak
Detector
Slicer
Clock
Recovery
Data
Recovery
Invert
RCLK1
LCV/(RCLK2)
LOSTHR
SDI
SDO/(LCV)
SClk
CS
REGRESET
TTIP
Pulse
Shaping
TRING
MTIP
MRING
DMO
Tx
Control
Serial
Processor
Interface
LOS Detector
HDB3/
B3ZS
Decoder
RPOS
RNEG
DECODIS
RLOS
LLB
RLB
ENCODIS
TAOS
TPDATA
TNDATA
Loop MUX
HDB3/
B3ZS
Encoder
Transmit
Logic
Duty Cycle Adjust
TClk
TXLEV
TXOFF
Device
Monitor
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
EXAR [ EXAR CORPORATION ]
