XR-T7295 Datasheet, PDF (1/20 Pages) Exar Corporation – DS3/Sonet STS-1 Integrated Line Receiver

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XR-T7295
DS3/Sonet STS-1
Integrated Line Receiver
FEATURES
D Fully Integrated Receive Interface for DS3 and
STS-1 Rate Signals
D Integrated Equalization (Optional) and Timing
Recovery
D Loss-of-Signal and Loss-of-Lock Alarms
D Variable Input Sensitivity Control
D 5V Power Supply
D Pin Compatible with XR-T7295E
D Companion Device to T7296 Transmitter
APPLICATIONS
D Interface to DS-3 Networks
D Digital Cross-Connect Systems
D CSU/DSU Equipment
D PCM Test Equipment
D Fiber Optic Terminals
June 1997-3
GENERAL DESCRIPTION
The XR-T7295 DS3/SONET STS-1 integrated line
receiver is a fully integrated receive interface that
terminates a bipolar DS3 (44.736Mbps) or Sonet STS-1
(51.84Mbps) signal transmitted over coaxial cable. (See
Figure 13).
The device also provides the functions of receive
equalization (optional), automatic-gain control (AGC),
clock-recovery and data retiming, loss-of-signal and
loss-of-frequency-lock detection. The digital system
interface is dual-rail, with received positive and negative
1s appearing as unipolar digital signals on separate
output leads. The on-chip equalizer is designed for cable
distances of 0 to 450ft. from the cross-connect frame to
the device. The receive input has a variable input
sensitivity control, providing three different sensitivity
settings, to adapt longer cables. High input sensitivity
allows for significant amounts of flat loss within the
system. Figure 1 shows the block diagram of the device.
The XR-T7295 device is manufactured using linear
CMOS technology. The XR-T7295 is available in either a
20-pin plastic DIP or 20-pin plastic SOJ package for
surface mounting.
Two versions of the chip are available, one is for either
DS3 or STS-1 operation (the XR-T7295, this data sheet),
and the other is for E3 operation (the XR-T7295E, refer to
the XR-T7295E data sheet). Both versions are pin
compatible.
For either DS3 or STS-1, an input reference clock at
44.736MHz or 51.84MHz provides the frequency
reference for the device.
ORDERING INFORMATION
Part No.
XR-T7295IP
XR-T7295IW
Package
20 Lead 300 Mil PDIP
20 Lead 300 Mil JEDEC SOJ
Operating
Temperature Range
-40°C to + 85°C
-40°C to + 85°C
Rev. 1.05
E1992
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 z [phone] z FAX [phone]
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