XRT7300 Datasheet, PDF (1/55 Pages) Exar Corporation – E3/DS3/STS-1 LINE INTERFACE UNIT

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XRT7300
FEBRUARY 2002
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.
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
NOTE: This Device is Protected by US Patent # 6,157,270
FIGURE 1. BLOCK DIAGRAM OF THE XRT7300
E3
STS-1/DS3
Host/(HW)
RLOL EXCLK
ICT
RCLK2INV
RTIP
RRING
REQDIS
LOSTHR
SDI
SDO/(LCV)
SClk
CS
REGRESET
TTIP
TRING
MTIP
MRING
DMO
AGC/
Equalizer
Peak
Detector
Slicer
Clock
Recovery
LOS Detector
Serial
Processor
Interface
Loop MUX
Data
Recovery
Invert
HDB3/
B3ZS
Decoder
Device
Monitor
Pulse
Shaping
Tx
Control
HDB3/
B3ZS
Encoder
Transmit
Logic
Duty Cycle Adjust
RCLK1
LCV/(RCLK2)
RPOS
RNEG
DECODIS
RLOS
LLB
RLB
ENCODIS
TAOS
TPDATA
TNDATA
TClk
TXLEV
TXOFF
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com