XR-T5794
Quad E-1 Line
Interface Unit
...the analog plus company
TM
Rev. 2.02
1994
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 (510) 668-7000 (510) 668-7017
1
June 1997-3
FEATURES
Meets CCITT G.703 Pulse Mask Template for
2.048Mbps (E1) Rates
Transmitter and Receiver Interfaces Can Be:
– Single Ended, 75
Capacitive or Transformer
Coupled
– Balanced, 100 or 120
Transformer Coupled
Minimum Return Loss is 20dB (Receive) and 18dB
(Transmit), Exceeds G.703 and ETSI 300 166
Specifications
Bipolar Outputs can be Disabled Individually (High Z
Outputs)
System Interface is TTL Compatible on Digital Input
and TTL/CMOS Compatible On Digital Output Pins
Individual Channel Loss of Signal Detection, Local
and Remote Digital Loopback
Fifth Driver For Monitoring and Testing
Low Power, CMOS Technology
Over-temperature Protection
APPLICATIONS
Multi-Line E1 Interface Cards
E1 Network Equipment
– Multiplexers
– Cross Connects
– Switching Systems
Fault Tolerant Systems
GENERAL DESCRIPTION
The XR-T5794 is an optimized line interface unit, built
using low power CMOS technology. The device contains
four independent E1 channels for primary rate, PCM
applications up to 2.048Mbps. Each channel performs
the driver and receiver functions necessary to convert
bipolar signals to TTL/CMOS compatible logic levels and
vice versa. The device supports single ended or
balanced line interfaces on each channel, thereby
providing the user an option of reducing system cost and
board space by replacing the transformer with a
capacitor.
Each of the four drivers can be independently disabled,
allowing
maximum
flexibility
management. Output pulses are fully CCITT G.703
compliant. Moreover, the return loss is at least 18dB over
a frequency range of 51kHz to 3.072MHz.
in
system
power
The slicing circuit in the receive path is able to tolerate a
maximum of 12dB of cable loss with a minimum input
sensitivity of 600mV over the operating temperature
range. Return loss on the receive interfaces is minimum
20dB from 51kHz to 3.072MHz.
Local and remote loopbacks can be performed on any of
the four channels. A separate loss of signal (LOS)
detection circuitry and a LOS pin is provided for each
input. A fifth transmitter has been provided to support
dedicated monitoring and testing purposes on any of the
eight bipolar paths. For designers not requiring the fifth
(monitor) driver, EXAR offers the XR-T5793, a pin
compatible version of the XR-T5794.
The XR-T5794 is targeted for multi-line E1 line card
applications where real estate, low power consumption
and back-up redundancy are critical. Also, the device
may be used in T1 applications (1.544Mbps) which do not
require meeting the DSX-1 cross connect pulse template.
ORDERING INFORMATION
Part No.
XR-T5794IJ
Package
68 Lead PLCC
Operating
Temperature Range
-40
°
C to +85
°
C
-40
°
C to +85
°
C
XR-T5794IV
80 Lead TQFP (14x14x1.4 mm)