XR-T5794
...the analog plus company
TM
Quad E-1 Line
Interface Unit
June 1997-3
FEATURES
D
Meets CCITT G.703 Pulse Mask Template for
2.048Mbps (E1) Rates
D
Transmitter and Receiver Interfaces Can Be:
– Single Ended, 75Ω Capacitive or Transformer
Coupled
– Balanced, 100 or 120Ω Transformer Coupled
D
Minimum Return Loss is 20dB (Receive) and 18dB
(Transmit), Exceeds G.703 and ETSI 300 166
Specifications
D
Bipolar Outputs can be Disabled Individually (High Z
Outputs)
D
System Interface is TTL Compatible on Digital Input
and TTL/CMOS Compatible On Digital Output Pins
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 in system power
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.
The slicing circuit in the receive path is able to tolerate a
maximum of 12dB of cable loss with a minimum input
ORDERING INFORMATION
D
Individual Channel Loss of Signal Detection, Local
and Remote Digital Loopback
D
Fifth Driver For Monitoring and Testing
D
Low Power, CMOS Technology
D
Over-temperature Protection
APPLICATIONS
D
Multi-Line E1 Interface Cards
D
E1 Network Equipment
– Multiplexers
– Cross Connects
– Switching Systems
D
Fault Tolerant Systems
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.
Part No.
XR-T5794IJ
XR-T5794IV
Package
68 Lead PLCC
80 Lead TQFP (14x14x1.4 mm)
Operating
Temperature Range
-40°C to +85°C
-40°C to +85°C
Rev. 2.02
E1994
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538
z
(510) 668-7000
z
(510) 668-7017
1
XR-T5794
BLOCK DIAGRAM
75Ω Unbalanced
(Without Transformer)
Impedance Selectable
Receivers. Return Loss
Exceeds G.703
TIP
0.47mF
75
Level
Detector
RXIN
100
or
120
E1/T1-
LOOPEN(1.4)
LPMOD(1.4)
Peak
Detector
Transceiver 1
Transceiver 2
Transceiver 3
Transceiver 4
LOS
Slicer
L
o
c
a
l
/
R
e
m
o
t
e
L
o
o
p
b
a
c
k
120Ω Balanced
TIP
(or 100Ω )
RX INPUT
RING
Impedance
Selectable
Tristate Drivers
Return Loss
Exceeds
ETSI 300 166
PE–65834
TTI 7148
RXPOS
RXNEG
Slice
Voltage
2
LOS Threshold Based on G.775
120Ω ,100Ω or 75Ω
balanced
TXOUT
R
OUT1
TXEN
TIP
TX OUTPUT
RING
PE–65839
TTI 7149
Driver
TXPOS
TXNEG
TXCLK
75Ω Unbalanced
(Without Transformer)
TIP
0.47µF
Channel 1
R
OUT1
Channel 2
Driver
Channel 3
Channel 4
MUX
MOUT
MSEL (0.2)
MONEM
Note
1
R
OUT
= 68Ω for 120Ω line impedance, R
OUT
= 62Ω for 100Ω line impedance, R
OUT
= 68Ω for 75Ω line impedance
Figure 1. Block Diagram
Rev. 2.01
2
XR-T5794
PIN CONFIGURATION
TXEN3
TXEN4
TXOUT4
TV
DD
TV
TXOUT3
AGND
TV
DD
MOUT
TV
AGND
TXOUT2
TV
TV
DD
TXOUT1
TXEN1
TXEN2
SS
SS
SS
2 1 68
MONEN
AV
DD
TCLK4
TXPOS4
TXNEG4
TXCLK3
TXPOS3
TXNEG3
LOOPEN4
LOOPEN3
GND
V
DD
RXPOS3
RXNEG3
RXPOS4
RXNEG4
RV
DD
10
60
26
27
LPMOD4
LPMOD3
RXIN4
LOS4
LOS3
RXIN3
MSEL0
MSEL1
RGND
RGND
MSEL2
RXIN2
LOS1
LOS2
44
43
RXIN1
LPMOD2
LPMOD1
LOSLVS
AV
SS
TXCLK2
TXPOS2
TXNEG2
TXCLK1
TXPOS1
TXNEG1
LOOPEN2
LOOPEN1
E1/T1-
V
SS
RXPOS2
RXNEG2
RXPOS1
RXNEG1
RV
SS
68 Lead PLCC
LOSLVS
AV
SS
AV
SS
AV
SS
TXCLK2
TXPOS2
TXNEG2
TXCLK1
TXPOS1
TXNEG1
LOOPEN2
LOOPEN1
E1/T1-
V
SS
RXPOS2
RXNEG2
RXPOS1
RXNEG1
RV
SS
RV
SS
60
NC
NC
TXEN2
TXEN1
TXOUT1
TV
DD
TV
SS
TXOUT2
AGND
TV
SS
MOUT
TV
DD
AGND
TXOUT3
TV
SS
TV
DD
TXOUT4
TXEN4
TXEN3
NC
61
41
40
NC
NC
LPMOD1
LPMOD2
RXIN1
LOS2
LOS1
RXIN2
MSEL2
RGND
RGND
RGND
MSEL1
MSEL0
RXIN3
LOS3
LOS4
RXIN4
LPMOD3
LPMOD4
80
1
20
21
80 Lead TQFP (14 x 14 x 1.4 mm)
Rev. 2.01
3
NC
MONEN
AV
DD
AV
DD
TXCLK4
TXPOS4
TXNEG4
TXCLK3
TXPOS3
TXNEG3
LOOPEN4
LOOPEN3
GND
V
DD
RXPOS3
RXNEG3
RXPOS4
RXNEG4
RV
DD
RV
DD
XR-T5794
PIN DESCRIPTION
PLCC
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
SQFP
Pin #
71
72
73
74
75
76
77
78
79
2
3,4
5
6
7
8
9
10
11
12
13
14
15
16
17
Symbol
MOUT
TV
DD
AGND
TXOUT3
TV
SS
TV
DD
TXOUT4
TXEN4
TXEN3
MONEN
AV
DD
TXCLK4
TXPOS4
TXNEG4
TXCLK3
TXPOS3
TXNEG3
LOOPEN4
LOOPEN3
GND
V
DD
RXPOS3
RXNEG3
RXPOS4
Type
O
V
DD
GND
O
V
SS
V
DD
O
I
I
I
V
DD
I
I
I
I
I
I
I
I
GND
V
DD
O
O
O
Description
Signal Monitor Output.
If MONEN=1, this output tracks the selected signal.
Hi-Z otherwise. The channel selection is done using MONSEL[2..0] inputs.
Transmit V
DD.
)5V
($5%).
Analog Ground.
Transmitter 3 Output.
Transmitter 3 bipolar output connected to coupling
capacitor or pulse transformer by a resistor.
Transmit V
SS.
-5V ($5%).
Transmit V
DD.
+5V ($5%).
Transmitter 4 Output.
Transmitter 4 bipolar output connected to coupling
capacitor or pulse transformer by a resistor.
Transmitter 4 Output Enable.
If driven high the transmitter 4 output drivers
are enabled. Hi-Z otherwise.
Transmitter 3 Output Enable.
If driven high the transmitter 3 output drivers
are enabled. Hi-Z otherwise.
Monitor/Test Output Enable.
If driven high the output driver of the MOUT
output is enabled. Hi-Z otherwise.
Analog V
DD.
Transmitter 4 Clock Input.
Apply logic one when RZ signals are supplied to
data inputs.
Transmitter 4 Positive Data In.
Positive data input in NRZ or RZ format for
transmitter 4.
Transmitter 4 Negative Data In.
Negative data input in NRZ or RZ format for
transmitter 4.
Transmitter 3 Clock Input.
Apply logic one when RZ signals are supplied to
data inputs.
Transmitter 3 Positive Data In.
Positive data input in NRZ or RZ format for
transmitter 3.
Transmitter 3 Negative Data In.
Negative data input in NRZ or RZ format for
transmitter 3.
Loop Enable 4.
If driven high the specified loop type will be enabled for chan-
nel 4. Otherwise normal operation will continue.
Loop Enable 3.
If driven high the specified loop type will be enabled for chan-
nel 3. Otherwise normal operation will continue.
Digital Ground.
Digital V
DD.
+5V ($5%).
Receiver 3 Positive Data Out.
Positive data output in NRZ or RZ format for
receiver 3.
Receiver 3 Negative Data Out.
Negative data output in NRZ or RZ format for
receiver 3.
Receiver 4 Positive Data Out.
Positive data output in NRZ or RZ format for
receiver 4.
Rev. 2.01
4
XR-T5794
PIN DESCRIPTION (CONT’D)
PLCC
Pin #
25
26
27
SQFP
Pin #
18
19, 20
21
Symbol
RXNEG4
RV
DD
LPMOD4
Type
O
V
DD
I
Description
Receiver 4 Negative Data Out.
Negative data output in NRZ or RZ format for
receiver 4.
Receive V
DD.
+5V ($5%).
Loop Mode 4.
If driven high the loopback mode of channel 4 will be set to re-
mote loop. Otherwise theloopback mode will remain at local loop. The
actual loopback will be activated when the LOOPEN4 is asserted.
Loop Mode 3.
If driven high the loopback mode of channel 3 will be set to re-
mote loop. Otherwise the loopback mode will remain at local loop. The
actual loopback will be activated when the LOOPEN3 is asserted.
Receiver 4 Input.
Receiver 4 bipolar input connected to coupling capacitor or
pulse transformer.
Receiver 4 Loss Of Signal.
Asserted during LOS condition. Clear otherwise.
Receiver 3 Loss Of Signal.
Asserted during LOS condition. Clear otherwise.
Receiver 3 Input.
Receiver 3 bipolar input connected to coupling capacitor or
pulse transformer.
Monitor Channel Select 0.
Select line, used to select a channel for monitoring
using the MOUT pin based on the following assignment:
MSEL2
0
0
0
0
1
1
1
1
MSEL1
0
0
1
1
0
0
1
1
MSEL0
0
1
0
1
0
1
0
1
SELECTS
Line 1 Receive
Line 2 Receive
Line 3 Receive
Line 4 Receive
Line 1 Transmit
Line 2 Transmit
Line 3 Transmit
Line 4 Transmit
28
22
LPMOD3
I
29
30
31
32
33
23
24
25
26
27
RXIN4
LOS4
LOS3
RXIN3
MSEL0
I
O
O
I
I
Note
The monitoring is only done on the NRZ data output signals from the receiver or from the
transmitter line side.
34
35
36
37
38
39
40
41
42
28
29, 30
31
32
33
34
35
36
37
MSEL1
RGND
RGND
MSEL2
RXIN2
LOS1
LOS2
RXIN1
LPMOD2
I
GND
GND
I
I
O
O
I
I
Monitor Channel Select 1.
See table above.
Receive Ground.
Receive Ground.
Monitor Channel Select 2.
See table above.
Receiver 2 Input.
Receiver 2 bipolar input connected to coupling capacitor or
pulse transformer.
Receiver 1 Loss Of Signal.
Asserted during LOS condition. Clear otherwise.
Receiver 2 Loss Of Signal.
Asserted during LOS condition. Clear otherwise.
Receiver 1 Input.
Receiver 1 bipolar input connected to coupling capacitor or
pulse transformer.
Loop Mode 2.
If driven high the loopback mode of channel 2 will be set to re-
mote loop. Otherwise the loopback mode will remain at local loop. The
actual loopback will be activated when the LOOPEN2 is asserted.
Rev. 2.01
5
