XRT5894
Four-Channel E1
Line Interface (3.3V or 5.0V)
March 2000-3
FEATURES
D Compliant with ITU G.703 Pulse Mask Template for
2.048Mbps (E1) Rates
D Four Independent CEPT Transceivers
D Logical Inputs Accept either 3.3V or 5.0V Levels
D Ultra-Low Power Dissipation
D +3.3V or 5.0V Supply Operations
D Supports Differential Transformer Coupled
Receivers and Transmitters
D On Chip Pulse Shaping for Both 75W and 120W Line
Drivers
D Compliant with ITU G.775 LOS Declaration/Clearing
Recommendation
D Optional User Selectable LOS Declaration/Clearing
Delay
D Individual Transmit Channel Over Temperature
Protection
APPLICATIONS
D SDH Multiplexer
D Digital Cross Connects
GENERAL DESCRIPTION
The XRT5894 is an optimized four channel 3.3V line
interface unit fabricated using low power CMOS
technology. The device contains four independent E1
channels. Each channel performs the driver and receiver
functions necessary to convert bipolar signals to logical
levels and vice versa. The device requires transformers
on both receiver and transmitter sides, and supports both
balanced and unbalanced interfaces.
The device offers two distinct modes of LOS detection.
The first method, which does not require an external
clock, provides an LOS output indication signal with
thresholds and delay that comply with the ITU G.775
requirements. In the second mode, the user provides an
external clock that increases the delay for LOS
declaration and clearing. This feature provides the user
with the flexibility to implement LOS specifications that
require a delay greater than the G.775 requirements.
ORDERING INFORMATION
Part No.
Package
Operating
Temperature Range
XRT5894IV
64 Lead TQFP (10 x 10 x 1.4mm)
-40°C to +85°C
Rev. 1.10
E2000
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 z (510) 668-7000 z FAX (510) 668-7017
XRT5894
BLOCK DIAGRAM
Transceiver 1
Transceiver 2
Transceiver 3
Tranceiver 4
RTIP4 (43)
RX Input
TIP
1:2
RXPOS4 (47)
R1
RING
R2
Signal
Peak
Detector
RRING4 (42)
Receive
Comparators
RXNEG4 (46)
VCC
LOS
Detect
LOSCNT (45)
Loss
Delay
Counter
1
Mux
O
LOS4 (48)
LOSSEL (25)
Transmit
Line
Drivers
TIP
TX OUTPUT
RING
2:1
R3
TTIP4 (53)
9.1
R4
Duty
Cycle
Adjust
Pulse
Shaping
TRING4 (55)
9.1
0
0
Mux
NRZ
To
RZ
TXCLK4 (51)
TXPOS4 (49)
TXNEG4 (50)
1
1
Figure 1. XRT5894 Block Diagram
Receiver Notes
D The same type 1:2CT ratio transformer may be
used at the receiver input and transmitter output.
D LOSCNT (pin 45) is unconnected when LOSSEL is
logic 1, or connected to an external clock when
LOSSEL is logic 0.
D R1 and R2 are both 150W for 75W operation, or
240W for 120W operation.
Transmitter Notes
D Return loss exceeds ITU G.703 specification with
these resistors and a 1:2CT ratio input transformer.
D Return loss exceeds ETSI 300 166 specification
with a 1:2 ratio transformer.
LOS (Loss of Signal) Notes
D R3 and R4 are always 9.1W for both 75W and 120W
applications.
D LOSSEL (pin 25) is connected to logic “1” for ITU
G.775 compliant LOS delay, or to logic 0 for user
programmable additional delay.
Rev. 1.10
2
XRT5894
LOS4
RXPOS4
RXNEG4
LOSCNT
GND
RTIP4
RRING4
GND
VCC
GND
TRING3
VCC
TTIP3
GND
RTIP3
RRING3
PIN CONFIGURATION
48
49
32
64
17
GND
TRING2
VCC
GND
VCC
16
RTIP1
RRING1
VCC
LOS1
RXPOS1
RXNEG1
VCC
1
TTIP2
GND
RTIP2
RRING2
TXPOS4
TXNEG4
TXCLK4
GND
TTIP4
VCC
TRING4
GND
GND
TRING1
VCC
TTIP1
GND
TXCLK1
TXNEG1
TXPOS1
33
64 LEAD THIN QUAD FLAT PACK
(10 x 10 x 1.4 mm, TQFP)
Rev. 1.10
3
TXCLK3
TXNEG3
TXPOS3
LOS3
RXPOS3
RXNEG3
GND
LOSSEL
NC
VCC
RXNEG2
RXPOS2
LOS2
TXPOS2
TXNEG2
TXCLK2
XRT5894
PIN DESCRIPTION
Pin #
Symbol
Type
Description
1
LOS1
O
Receiver 1 Loss of Signal. Asserted during LOS condition.
2
RXPOS1
O
Receiver 1 Positive Data Out. Positive RZ data output for channel 1.
3
RXNEG1
O
Receiver 1 Negative Data Out. Negative RZ data output for channel 1.
4
VCC
5
RTIP1
I
Receiver 1 Positive Bipolar Input.
6
RRING1
I
Receiver 1 Negative Bipolar Input.
7
VCC
Positive Supply (+3.3V or +5.0V + 5%). Analog circuitry.
8
GND
Analog Ground.
9
VCC
Positive Supply. (+3.3V or +5.0V + 5%). Analog circuitry.
10
GND
Analog Ground.
11
TRING2
12
VCC
13
TTIP2
Positive Supply (+3.3V or +5.0V + 5%). Digital circuitry.
O
Transmitter 2 Negative Bipolar Output.
Positive Supply (+3.3V or +5.0V + 5%). Transmitter channel 2.
O
Transmitter 2 Positive Bipolar Output.
14
GND
15
RTIP2
I
Analog Ground. Transmitter channel 2.
Receiver 2 Positive Bipolar Input.
16
RRING2
I
Receiver 2 Negative Bipolar Input.
17
TXCLK2
I
Transmitter 2 Clock Input. Use for clocked mode with NRZ data.1
18
TXNEG2
I
Transmitter 2 Negative Data Input. Negative NRZ or RZ data input.1
19
TXPOS2
I
Transmitter 2 Positive Data Input. Positive NRZ or RZ data input.1
20
LOS2
O
Receiver 2 Loss of Signal. Asserted during LOS condition.
21
RXPOS2
O
Receiver 2 Positive Data Out. Positive RZ data output for channel 2.
22
RXNEG2
O
Receiver 2 Negative Data Out. Negative RZ data output for channel 2.
23
VCC
Positive Supply (+3.3V or +5.0V + 5%). Digital circuitry.
24
NC
No Connect.
25
LOSSEL
26
GND
27
RXNEG3
O
Receiver 3 Negative Data Out. Negative RZ data output for channel 3.
28
RXPOS3
O
Receiver 3 Positive Data Out. Positive RZ data output for channel 3.
29
LOS3
O
Receiver 3 Loss of Signal. Asserted during LOS condition.
30
TXPOS3
I
Transmitter 3 Positive Data Input. Positive NRZ or RZ data input.1
31
TXNEG3
I
Transmitter 3 Negative Data Input. Negative NRZ or RZ data input.1
32
TXCLK3
I
Transmitter 3 Clock Input. Use for clocked mode with NRZ data.1
33
RRING3
I
Receiver 3 Negative Bipolar Input.
34
RTIP3
I
Receiver 3 Positive Bipolar Input.
I
Loss of Signal Delay Select. “Hi” selects G.775, “Lo” selects user programmable.1
Digital Ground.
Note:
1 Has internal pull-up 50KW resistor.
Rev. 1.10
4
XRT5894
PIN DESCRIPTION (CONT’D)
Pin #
Symbol
Type
Description
35
GND
36
TTIP3
37
VCC
38
TRING3
39
GND
Analog Ground. Transmitter channel 3.
40
VCC
Positive Supply (+3.3V or +5.0V + 5%). Analog circuitry.
41
GND
Analog Ground.
42
RRING4
I
Receiver 4 Negative Bipolar Input.
43
RTIP4
I
Receiver 4 Positive Bipolar Input.
44
GND
45
LOSCNT
I
Loss of Signal Timing Clock Input. For user--programmable LOS delay.1
46
RXNEG4
O
Receiver 4 Negative Data Out. Negative RZ data output for channel 4.
47
RXPOS4
O
Receiver 4 Positive Data Out. Positive RZ data output for channel 4.
48
LOS4
O
Receiver 4 Loss of Signal. Asserted during LOS condition.
49
TXPOS4
I
Transmitter 4 Positive Data Input. Positive NRZ or RZ data input.1
50
TXNEG4
I
Transmitter 4 Negative Data Input. Negative NRZ or RZ data input.1
51
TXCLK4
I
Transmitter 4 Clock Input. Use for clocked mode with NRZ data.1
Analog Ground.
O
Transmitter 3 Positive Bipolar Output.
Positive Supply (+3.3V or +5.0V + 5%). Transmitter channel 3.
O
Transmitter 3 Negative Bipolar Output.
Analog Ground.
52
GND
53
TTIP4
Analog Ground. Transmitter channel 4.
54
VCC
55
TRING4
56
GND
Digital Ground.
57
GND
Analog Ground.
58
TRING1
O
Transmitter 4 Positive Bipolar Output.
Positive Supply (+3.3V or +5.0V + 5%). Transmitter channel 4.
O
O
Transmitter 4 Negative Bipolar Output.
Transmitter 1 Negative Bipolar Output.
59
VCC
60
TTIP1
Positive Supply (+3.3V or +5.0V + 5%). Transmitter channel 1.
61
GND
62
TXCLK1
I
Transmitter 1 Clock Input. Use for clocked mode with NRZ data.1
63
TXNEG1
I
Transmitter 1 Negative Data Input. Negative NRZ or RZ data input.1
64
TXPOS1
I
Transmitter 1 Positive Data Input. Positive NRZ or RZ data input.1
O
Transmitter 1 Positive Bipolar Output.
Analog Ground. Transmitter channel 1.
Note:
1 Has internal pull-up 50KW resistor.
Rev. 1.10
5
XRT5894
ELECTRICAL CHARACTERISTICS
Test Conditions: VCC = 3.3V or 5.0V + 5%, TA = -40 to 25 to 85°C, Unless Otherwise Specified
Symbol
Parameter
Min.
Typ.
Max.
Unit
Conditions
DC Electrical Characteristics
Parameters
VCC
Voltage Supply
3.135
3.3
3.465
V
3.3V Operation
VCC
Voltage Supply
4.75
5.0
5.25
V
5V Operation
VIH
Input High Level
2.0
5.0
V
VIL
Input Low Level
0.8
V
Inputs
Outputs
VOH
Output High Level
VOL
Output Low Level
2.4
V
IOH = -4mA
0.4
V
IOL = 4mA
12
dB
Cable loss at 1.024MHz (Relative
to 0dB = 2.37Vp measured from
RTIP or RRING to ground).
dB
With 6dB cable loss
Receiver Specifications
RXCL
Allowable Cable Loss
0
10
RXIM
Interference Margin
-15
-12
RXXI
Receiver Slicing Threshold
45
50
55
%
% of peak input voltage at -3dB
cable loss
15
32
dB
Relative to 0dB = 2.37Vp
Measured from RTIP or RRING to
ground.
dB
Relative to 0dB = 2.37Vp
measured from RTIP or RRING to
ground.
RXLOSSET
LOS Must Be Set If RX Sig.
Atten. ² 32dB (For Any Valid
Data Pattern)
RXLOSCLR
LOS Must Be Cleared If RX Sig.
Atten. < 9dB
9
RXLOSHYST
Hysteresis on Input Data
1
dB
For LOS output state change
Input Impedance
5
kW
Up to 3.072MHz (Measured from
RTIP or RRING to ground).
RXIN
12
Power Specifications VCC = 3.3V
PD
Power Dissipation
460
590
mW
All 1’s Transmit and Receive 75W
PD
PC
Power Dissipation
117
155
mW
All Drivers Power Down
Power Consumption 75W
770
900
mW
All 1’s Transmit and Receive
PC
Power Consumption 75W
555
675
mW
50% data density, Transmit and Receive
PC
Power Consumption 120W
635
780
mW
All 1’s Transmit and Receive
PC
Power Consumption 120W
475
605
mW
50% data density, Transmit and Receive
Power Specifications VCC = 5.0V
PD
Power Dissipation
945
1240
mW
All 1’s Transmit and Receive 75W
PD
Power Dissipation
235
290
mW
All Drivers Power Down
PC
Power Consumption 75W
1250
1555
mW
All 1’s Transmit and Receive
Note:
Bold face parameters are covered by production test and guaranteed over operating temperature range.
Rev. 1.10
6
XRT5894
ELECTRICAL CHARACTERISTICS (CONT’D)
Test Conditions: VCC = 3.3V or 5.0V + 5%, TA = -40 to 25 to 85°C, Unless Otherwise Specified
Symbol
Parameter
Min.
Typ.
Max.
Unit
Conditions
Power Specifications VCC =5.0V (Cont’d)
PC
Power Consumption 120W
1075
1345
mW
All 1’s Transmit and Receive
PC
Power Consumption 75W
1025
1300
mW
50% data density, Transmit and Receive
PC
Power Consumption 120W
940
1220
mW
50% data density, Transmit and Receive
AC Electrical Characteristics
VTXOUT
Output Pulse Amplitude
(RL = 75W)
2.13
2.37
2.60
V
Trans. = 1:2 ratio, 9.1W in series
with each end of primary
VTXOUT
Output Pulse Amplitude
(RL = 120W)
2.70
3.0
3.30
V
Trans. = 1:2 ratio, 9.1W in series
with each end of primary
TXPW
Output Pulse Width
224
244
264
ns
PNIMP
Pos/Neg Pulse Unbalanced
5
%
488
ns
T1
TXCLK Clock Period (E1)
T2
TXCLK Duty Cycle
30
TSU
Data Set-up Time, TDATA to
TXCLK
75
ns
50% TXCLK Duty Cycle
THO
Data Hold Time, TDATA to
TXCLK
30
ns
50% TXCLK Duty Cycle
50
70
%
TR
TXCLK Rise Time (10% to 90%)
40
ns
TF
TXCLK Fall Time (10% to 90%)
40
ns
Data Prop. Delay No-Clock
Mode
35
Data Prop. Delay Clock Mode
470
T3-noclk
T3-clk
50
ns
50% TXCLK Duty Cycle
T4
Receive Data High
269
ns
0dB Cable Loss
T5
RX Data Prop. Delay
40
ns
15pF Load
T6
Receive Rise Time
40
ns
15pF Load
T7
Receive Rise Time
40
ns
15pF Load
219
244
ns
Note:
Bold face parameters are covered by production test and guaranteed over operating temperature range.
ABSOLUTE MAXIMUM RATINGS
Storage Temperature . . . . . . . . . . . . -65°C to +150°C
Operating Temperature . . . . . . . . . . -40°C to +85°C
Supply Voltage . . . . . . . . . . . . . . . . . . . -0.3V to +6.0V
ESD Protection . . . . . . . . . . . . . . . . . . >1000V (HBM)
Rev. 1.10
7
XRT5894
Disabling Output Drivers
Output drivers may be individually disabled (hi-z output) by either of the following methods.
1. Either connect the transmit data inputs TXPOS
and TXNEG for the channel to be disabled to a logic 1 source (VCC), or allow them to float (inputs
have internal pull--up resistors).
2. Connect TXCLK for the channel to be disabled to
logic 0 source (Ground), and also apply data to the
TXPOS and TXNEG inputs of that channel.
TRANSFORMER REQUIREMENTS
Turns Ratio
Line Impedance
Turns Ratio
Line Impedance
1:2 CT
75W or 120W
1:2
75W or 120W
Table 1. Input Transformer Requirements
Table 2. Output Transformer Requirements
Note:
The same type 1:2 CT ratio device may be used at both receiver input and transmitter output.
The following transformers have been tested with the
XRT5894:
HALO type TG26-1205(package contains two 1 CT:2 CT ratio transformers)
Pulse type PE-65535 (1:2 CT ratio)
Transpower Technologies type TTI 7154-R (1:2 CT ratio)
Magnetic Supplier Information:
HALO Electronics, Inc.
P.O. Box 5826
Redwood City, CA 94063
Tel. (415) 568-5800
Fax. (415)568-6161
Pulse
Telecom Product Group
P.O. Box 12235
San Diego, CA 92112
Tel. (619) 674-8100
Fax. (619) 674-8262
Transpower Technologies, Inc.
24 Highway 28, Suite 202
Crystal Bay, NV 89402--0187
Tel. (702) 831--0140
Fax. (702) 831--3521
Rev. 1.10
8
XRT5894
TSU
THO
TXPOS (n)
TSU
TXNEG (n)
T2
T1
TR
TXCLK (n)
THO
TF
TXPW
T3
T3
VTXOUT
TXOUT (n)
VTXOUT
TXPW
Figure 2. Transmit Timing Diagram
RXIN (n)
T5
T4
T6
T7
RPOS (n)
T5
T4
RXNEG (n)
Figure 3. Receive Timing Diagram
Rev. 1.10
9
T6
T7
XRT5894
RETURN LOSS SPECIFICATIONS
The following transmitter and receiver return loss specifications are based on a typical 1:2CT ratio transformer.
75W
120W
Frequency Range
Min.
Typ.
Min.
Typ.
Unit
51kHz to 102kHz
16
22
10
15
dB
102kHz to 2.048MHz
16
22
10
15
dB
2.048MHz to 3.072MHz
11
18
10
14
dB
Table 3. Transmitter Return Loss Specification
Transmit Return Loss Notes
D Output transformer ratio is 1:2 (return loss exceeds
ETSI 300 166 with this transformer).
D For both 75W and 120W applications, 9.1W, 1% resistors are connected between each end of the
transformer primary and the XRT5894 TTIP and
TRING pins.
75W
120W
Frequency Range
Min.
Typ.
Min.
Typ.
Unit
51kHz to 102kHz
16
28
15
18
dB
102kHz to 2.048MHz
22
34
22
25
dB
2.048MHz to 3.072MHz
18
26
20
30
dB
Table 4. Receiver Return Loss Specification
Receiver Return Loss Notes
D Input transformer ratio is 1:2 CT.
D Each half of transformer secondary is terminated
with 150W for 75W operation, or 240W for 120W operation (resistors are 1% tolerance).
D Transformer center tap is grounded.
Rev. 1.10
10
XRT5894
SYSTEM DESCRIPTION
This device is a four channel E1 transceiver that provides
an electrical interface for 2.048Mbps applications. Its
unique architecture includes four receiver circuits that
convert ITU G.703 compliant bipolar signals to TTL
compatible logic levels. Each receiver includes a LOS
(Loss of Signal) detection circuit that may be configured
for either a fixed or a user-programmable LOS response
time delay. Similarly, in the transmit direction, four
transmitters convert TTL compatible logic levels to G.703
compatible bipolar signals. Each transmitter may be
operated either with RZ, or NRZ data types. In NRZ mode
a transmit clock is required as well. The following
description applies to any of the four receivers or
transmitters contained in the XRT5894. Therefore, the
suffix numbers for a particular channel are deleted for
simplicity. i.e. “RTIP” applies to RTIP1 through RTIP4.
specified in the ITU G.775. This is done by providing a
user-supplied clock to LOSCNT (pin 45). The “user
programmable mode” is provisioned to allow systems
designers to comply with older versions of LOS
specifications in legacy systems. It needs to be stressed
that the delay for declaration and clearing of the LOS
condition will never be less than the range specified in the
G.775 specification (10-255 pulse intervals).
The LOS detection/clearing circuitry of the XRT5894 in
“automatic” mode will detect LOS when the incoming
signal has “no transitions” i.e. when the signal level is less
than or equal to a signal level AD dB below nominal signal
level, for N consecutive pulse intervals, where 10
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