EXAR XR-T7296IW

XR-T7296
...the analog plus company TM
DS3/STS–1, E3
Integrated Line Transmitter
June 1997-3
APPLICATIONS
FEATURES
Interface for SONET, DS-3 and E3 Network
Equipment
Fully Integrated Transmit Interface for
DS3/STS-1 or E3
Digital Cross-Connect Systems
Integrated Pulse Shaping Circuit
CSU/DSU Equipment
Compliance with Compatibility Bulletin 119
PCM Test Equipment
Compliance with CCITT Recommendations
G.703 & G.824
Fiber Optic Terminals
Compliance with Bellcore TR-NWT-000499
Compliance with ANSI T1.404
Built-in B3ZS/HDB3 Encoder and Decoder
Remote and Local Loopback Functions
Single 5V Power Supply
GENERAL DESCRIPTION
The XR-T7296 is a fully integrated PCM Line Driver IC
intended for DS3 (44.736Mbps) or E3 (34.368Mbps)
applications. It can also be used for transmitting SONET
STS-1 (51.84Mbps) signals over coaxial cable. The IC is
designed to complement either XR-T7295 DS3/SONET
STS-1 or XR-T7295E E3 Integrated Line Receivers. The
XR-T7296 converts input clock and dual-rail unipolar data
into AMI pulses according to AT&T Technical Advisory
No. 34 or CCITT G.703 recommendations.
disabled independently through external control pins. In
the receive direction, coding errors and bipolar violations
are detected and flagged at an output pin.
The device provides B3ZS (DS3) or HDB3 (E3) encoding
functions for data to be transmitted to the line. A
complimentary decoder circuit is also included in the chip
for decoding received signals from an external line
receiver. Both encoder and decoder functions can be
The XR-T7296 is manufactured using BiCMOS
technology and is packaged in a 28-pin PDIP or SOJ
packages. The device requires a single 5V power supply
and consumes a maximum power of 700mW. (Line
current feed + device dissipation).
On-chip pulse shaper circuitry eliminates normally
required external components for line equalization to
meet the cross-connect template. For system level
trouble-shooting and testing, both local and remote
loop-backs are possible with the built-in loop-back circuit.
ORDERING INFORMATION
Part No.
Package
Operating
Temperature Range
XR-T7296IP
28 Lead 600 Mil PDIP
-40°C to + 85°C
XR-T7296IW
28 J Lead 300 Mil JEDEC SOJ
-40°C to + 85°C
Rev. 2.01
1992
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 (510) 668-7000 FAX (510) 668-7017
1
XR-T7296
BLOCK DIAGRAM
TAOS
ENCODIS
TXLEV
11
25
5
TPDATA
AMP1
7
TNDATA
8
TCLK
9
B3ZS/HDB3
Encoder
Pulse
Shaper
27
RNDATA
28
RCLK
DS3, STS-1/E3
B3ZS/HDB3
Decoder
1
4
MRING
19
MTIP
20
Driver
Monitor
2
3
RLOOP LLOOP
6
10
21
2
24
VDDD GNDD GNDA VDDA
Figure 1. XR-T7296 Block Diagram
Rev. 2.01
TTIP
22
TRING
12
DECODIS
13
BPV
14
RNRZ
15
RNEG
16
RPOS
17
RCLKO
18
DMO
AMP2
Loop
Back
MUX
RPDATA
23
26
ICT
XR-T7296
PIN CONFIGURATION
RCLK
RLOOP
LLOOP
DS3,STS-1/E3
TAOS
VDDD
TPDATA
TNDATA
TCLK
GNDD
ENCODIS
RNDATA
RPDATA
ICT
TXLEV
VDDA
TTIP
TRING
GNDA
MTIP
MRING
DMO
1
28
2
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
DECODIS
BPV
12
17
13
16
RCLKO
RPOS
RNRZ
14
15
RNEG
RCLK
RLOOP
LLOOP
DS3,STS-1/E3
TAOS
VDDD
TPDATA
TNDATA
TCLK
GNDD
ENCODIS
DECODIS
BPV
RNRZ
28 Lead PDIP (0.600”)
1
28
2
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
12
17
13
16
14
15
RNDATA
RPDATA
ICT
TXLEV
VDDA
TTIP
TRING
GNDA
MTIP
MRING
DMO
RCLKO
RPOS
RNEG
28 Lead SOJ (Jedec, 0.300”)
PIN DESCRIPTION
Pin #
Symbol
Type
Description
1
CLK
I
Receive Clock Input. Input sampling clock for RPDATA and RNDATA.
2
RLOOP
I
Remote Loop Back. A high on this pin causes RPDATA and RNDATA to transmitted to the
line using RCLK. Setting RLOOP and LLOOP high simultaneously is not permitted.
3
LLOOP
I
Local Loop Back. A high on this pin causes TPDATA and TNDATA to pass through the encoder and output at RPOS and RNEG respectively. Setting LLOOP and RLOOP high simultaneously is not permitted.
4
DS3,STS-1/
E3
I
DS3, STS-1 or E3 Select Pin. A high on this pin selects DS3 or STS-1 operation and sets the
encoder and decoder in B3ZS mode. A low selects E3 and sets the encoder and decoder in
HDB3 mode.
5
TAOS
I
Transmit All Ones Select. A high on this pin causes a continuous AMI all 1’s pattern to be
transmitted to the line. The frequency is determined by TCLK.
6
VDDD
7
TPDATA
I
Transmit Positive Data. TPDATA is sampled on the falling edge of TCLK. Pin 7 and pin 8
can be tied together for binary input signals.
8
TNDATA
I
Transmit Negative Data. TNDATA is sampled on the falling edge of TCLK. Pin 7 and pin 8
can be tied together for binary input signals.
9
TCLK
I
Transmit Clock for TPDATA and TNDATA.
10
GNDD
11
ENCODIS
I
Encoder Disable. A high on this pin disables B3ZS or HDB3 encoding functions, unless overridden by TAOS request. This pin must be set high if TPDATA and TNDATA are already encoded.
12
DECODIS
I
Decoder Disable. A high on this pin disables B3ZS or HDB3 decoding functions.
5 V Digital Supply (5%) for all logic circuitry.
Digital Ground for all logic circuitry.
Rev. 2.01
3
XR-T7296
PIN DESCRIPTION (CONT’D)
Pin #
Symbol
Type
Description
13
BPV
O
Bipolar Violation Output. This pin goes high for one bit period when a bipolar violation not
corresponding to the appropriate coding rule or coding error is detected in the RPDATA/
RNDATA signals.
14
RNRZ
O
Receive Binary Data. Signal on this pin is the ORed-output of RPOS and RNEG.
15
RNEG
O
Receive Negative Data. This signal is the decoded version of RNDATA.1
16
RPOS
O
Receive Positive Data. This signal is the decoded version of RPDATA.1
17
RCLKO
O
Receive Clock Output. This signal is the inverted version of RCLK.
18
DMO
O
Driver Monitor Output. If no transmitted AMI signal is present on MTIP and MRING for
128 32 TCLK clock periods. DMO goes high until the next AMI signal is detected.
19
MRING
I
Monitor Ring Input. AMI signal from TRING can be connected to this pin for line driver failure detection. Internally pulled high.
20
MTIP
I
Monitor Tip Input. AMI signal from TTIP can be connected to this pin for line driver failure
detection. Internally pulled high.
21
GNDA
22
TRING
O
Transmit Ring Output. Transmit AMI signal is driven to the line via a 1:1 transformer from
this pin.
23
TTIP
O
Transmit Tip Output. Transmit AMI signal is driven to the line via a 1:1 transformer from this
pin.
24
VDDA
-
5V Analog Supply (5%) for analog circuitry.
25
TXLEV
I
Transmit Level Select. The output signal amplitude at TTIP and TRING can be varied by
setting this pin high or low. When the cable length is greater than 225 ft. TXLEV should be set
high. When it is below 225 ft, it should be set low. This pin is active only with pin 4 set to
DS3 or STS-1 mode.
26
ICT
I
In-circuit Testing. A low at this pin causes all digital and analog outputs to go into a high-impedance state to allow for in-circuit testing. Internally pulled high.
27
RPDATA
I
Receive Positive Data. NRZ input data to the decoder block. Sampled on the falling edge of
RCLK.
28
RNDATA
I
Receive Negative Data. NRZ input data of the decoder block. Sampled on
falling edge of RCLK.
Analog Ground for analog circuitry.
Note
1 If a bipolar violation occurs, RPOS and RNEG can correspond to the decoded versions of RNDATA and RPDATA respectively. If
DECODIS is high, RPOS and RNEG always track RPDATA and RNDATA respectively.
Rev. 2.01
4
XR-T7296
ELECTRICAL CHARACTERISTICS (See Figure 8 )
Test Conditions: VDD = 5V 5%, TA = -40°C to +85°C, unless otherwise specified. All timing characteristics
are measured with 10pF loading.
Symbol
Parameter
Min.
Typ.
Max.
Units
TCLK Clock Duty Cycle (DS3 / STS-1)
45
50
55
%
TCLK Clock Duty Cycle (E3)
47
50
53
%
AC Electrical Characteristics
tR
TCLK Clock Rise Time (10% to 90%)
4.0
ns
tF
TCLK Clock Fall Time (10% to 90%)
4.0
ns
tTSU
TPDATA/TNDATA to TCLK Falling Set Up Time
4.0
ns
tTHO
TPDATA/TNDATA to TCLK Falling Hold Time
5.0
ns
tTDY
TTIP/TRING to TCLK Rising Propagation Delay 1
0.6
RCLK Clock Duty Cycle
45
50
14
ns
55
%
tR
RCLK Clock Rise Time (10% to 90%)
4.0
ns
tF
RCLK Clock Fall Time (10% to 90%)
4.0
ns
tRSU
RPDATA/RNDATA to RCLK Falling Set Up Time
4.0
ns
tRHO
RPDATA/RNDATA to RCLK Falling Hold Time
5.0
ns
tR
RCLKO Clock Rise Time (10% to 90%)
4.0
ns
tF
RCLKO Clock Fall Time (10% to 90%)
4.0
ns
RPOS/RNEG/RNRZ to RCLKO Rising Propagation
Delay 2
4.0
ns
5.25
V
133
mA
tRDY
DC Electrical Characteristics
VDDD,
VDDA
DC Supply Voltage
4.75
Supply Current 3
5
VIL
Input Low Voltage
0
0.5
V
VIH
Input High Voltage
VDD* 0.7
VDDD
V
VOL
Output Low Voltage IOUT=-4.0mA
GNDD
0.4
V
VOH
Output High Voltage IOUT=3.0mA
VDDD - 0.5
VDDD
V
10
µA
-150
µA
IL
Input Leakage Current 4
Pin 19/20/26 (Input=0V)
-50
CI
Input Capacitance
10
pF
CL
Load Capacitance
10
pF
Notes:
1 When the encoder is enabled, a handling delay of four and a half TCLK clock cycles for B3ZS and five and half clock cycles for HDB3
always exists between TPDATA/TNDATA and TTIP/TRING. The handling delay is reduced to two clock cycles when the encoder
is disabled.
2 When the decoder is enabled, a handling delay of six and a half RCLK clock cycles will always exist between RPDATA/RNDATA
and RPOS/RNEG/RNRZ. The handling delay is reduced to one and half RCLK clock cycles when the decoder is disabled.
3 Supply current is measured with transmitter sending all ones AMI signal and with Transmit Level (TXLEV) set to high.
4 All inputs except pin 19, 20 and pin 26.
Specifications are subject to change without notice
Rev. 2.01
5
XR-T7296
ABSOLUTE MAXIMUM RATINGS
Power Supply . . . . . . . . . . . . . . . . . . . . . . . -0.5 to +6.5V
Power Dissipation DIP Pkg. . . . . . . . . . . . . . . . . . . . 1W
Storage Temperature . . . . . . . . . . . . . . -65°C to 150°C
Input Voltage (Any Pin) . . . . . . . . -0.5V to VDD + 0.5V
Voltage At Any Pin . . . . . . . . . . . . -0.5V to VDD +0.5V
Input Current (Any Pin) . . . . . . . . . . . . . . . . . . . . . 10mA
Power Dissipation SOJ Pkg. . . . . . . . . . . . . . . 725mW
SYSTEM DESCRIPTION
B3ZS/HDB3 ENCODER
LOCAL LOOPBACK
Data to be transmitted is input to the encoder block to be
encoded either in B3ZS or HDB3 as determined by the
state of the DS3,STS-1/E3 pin. Input data format can be
unipolar or binary. For binary signals, TPDATA and
TNDATA need to be connected together externally. The
line code used for DS3 is B3ZS. In this mode, each block
of three consecutive zeros is removed and replaced by
one of two codes which contain bipolar violation. These
replacement codes are B0V and 00V; where B indicates a
pulse conforming with the bipolar rule and V represents a
pulse violating the rule. The choice of these codes is
made such that an odd number of B pulses will be
transmitted between consecutive bipolar violation (V)
pulses. For E3 format, the line code is HDB3. The
encoding rule of HDB3 is similar to B3ZS except the
number of consecutive zeros is increased to four before a
code replacement can take place. The replacement
codes in this case are 000V and B00V.
Setting LLOOP high causes TPDATA and TNDATA to go
through both the encoder and the decoder. In this mode,
the transmit signal RCLKO, RPOS and RNEG
corresponds to TCLK, TPDATA and TNDATA
respectively. Unless overriden by TAOS request,
TPDATA and TNDATA will still be transmitted to the line.
Setting RLOOP and LLOOP high simultaneously is not
permitted.
B3ZS/HDB3 DECODER
The decoder block is included to perform B3ZS or HDB3
decoding as determined by the state of the DS3,
STS-1/E3 pin. In the B3ZS format, the decoder detects
both B0V and 00V pulses and replaces them with 000
data. If HDB3 decoding is selected by setting the DS3,
STS-1/E3 pin low, B00V and 000V pulses will be detected
and replaced with 0000 code. In both cases, bipolar
violation and coding errors which do not conform to the
coding scheme are detected and indicated at the BPV
output pin.
STS-1 operation is achieved by placing the part in the
DS3 mode and using 51.84 MHz clocks. Logic operation
for STS-1 is the same for DS3.
DECODER DISABLE
TRANSMIT ALL ONE SELECT
For testing purposes and in applications where the
decoder needs to be bypassed, the decoder can be
disabled by setting DECODIS high. In this mode all
bipolar violation pulses are indicated at the BPV pin.
Setting TAOS high causes continuous AMI encoded 1s to
be transmitted to the line. In this mode, input TPDATA and
TNDATA are ignored. If remote loop back (RLOOP) is set
high, any TAOS request is ignored.
BIPOLAR VIOLATION
REMOTE LOOP-BACK
The BPV pin will go high for one bit period when a bipolar
violation not corresponding to the appropriate coding rule
or a code error is detected on the RPDATA/RNDATA. The
violation pulse is always removed from the decoder
output RPOS / RNEG when DECODIS is set low.
Setting RLOOP high causes receive RPDATA and
RNDATA to be transmitted to the line through TTIP and
TRING. The data rate is determined by RCLK. In this
mode, TPDATA and TNDATA are ignored.
Rev. 2.01
6
XR-T7296
PULSE SHAPER
TTIP
The pulse shaper circuit uses a combination of filters and
slew rate control techniques to pre-shape the pulse going
out to the line. The amplitude of the transmit pulse can be
adjusted using the TXLEV (Transmit Level) pin. When the
distance to the cross-connect exceeds 225 ft, TXLEV
should be set high. When the distance is less than 225 ft.
TXLEV should be set low. Setting TXLEV high enables
the transmitter to send out a nominal voltage of 1.0V
peak, and 850mV peak when low. The state of TXLEV pin
has no effect on E3 operation.
365%
1:1
755%
TRING
365%
1
3
Note
1 Transformer = Pulse Engineering PE 65966, PE 65967
Surface Mount, Same Transformer for DS3, STS-1 and
E3.
Figure 2. Transmit Pulse Amplitude Test Circuit
DRIVER MONITOR
Using TTIP and TRING as input, the driver monitor
detects driver failure by monitoring the activities at MTIP
and MRING. If no signal is detected on these pins for 128
TCLK cycles 32 cycles, DMO will be set high until the
next AMI signal is detected.
Parameter
Value
Turn Ratio
1:1
Primary Inductance
40µH
Isolation Voltage
1500Vrms
Leakage Inductance
0.6µH
Table 1. Transmit Transformer Characteristics
Rev. 2.01
7
XR-T7296
DS3 SIGNAL REQUIREMENTS AT THE DSX
For DS3 operation, pulse characteristics are specified at
the DSX-3, which is an interconnection and test point
referred to as the crossconnect. The crossconnect exists
at the point where the transmitted signal reaches the
distribution frame jack.
The DSX-3 interconnection
specification tables list the signal requirements (Table 1).
The XR-T7296 can transmit through 450 feet of 782A
cable to the DSX-3 in DS3 mode.
Currently, two isolated pulse template requirements exist:
the ANSI T1.404 pulse template (See Table 3 and Figure
3) and the Bellcore TR-NWT-000499 pulse template. The
pulse transmitted by the XR-T7296 meets these
templates.
Parameter
Specification
Line Rate
44.736Mbps $20 ppm
Line Code
Bipolar with three-0 substitution (B3ZS)
Test Load
75 Ω 5%
Pulse Shape
An isolated pulse must fit the template in Figure 3 or Figure 4.1 The pulse amplitude may
be scaled by a constant factor to fit the template. The pulse amplitude must be between 0.36Vpk and 0.85Vpk, measured at the center of the pulse.
Power Levels
For an all 1s transmitted pattern, the power at 22.368 $ 0.002MHz must be -1.8 to
+5.7dBm, and the power at 44.736 $.002MHz must be -21.8dBm to -14.3dBm.2, 3
Notes
1
The pulse template proposed by G.703 standards is shown in Figure 4 and specified in Table 4 The proposed G.703 standards
further state that the voltage in a time slot containing a 0 must not exceed 5% of the peak pulse amplitude, except for the residue
of preceding pulses.
2 The power levels specified by the proposed G.703 standards are identical except that the power is to be measured in 3kHz bands.
3 The all 1s pattern must be a pure all 1s signal, without framing or other control bits.
Table 2. DSX–3 Interconnection Specification
Lower Curve
Time
T -0.36
-0.36 T +0.36
0.5 [1 +
Upper Curve
Equation
Time
-0.03
T -0.68
sinπ/2
+0.36 T
-0.68 T + 0.36
[1 +T/0.18 ]]-0.03
-0.03
+0.36
Equation
+0.03
0.5[ 1 +
sinπ/2
[1 +T/0.34]]+0.03
0.05+0.407e-1.84(T-0.36)
Table 3. DSX-3 Pulse Template Boundaries for ANSI T1.404 Standards (See Figure 3. )
Lower Curve
Time
-0.85 T -0.36
-0.36 T +0.36
+0.36 T +1.4
0.5 [1 +
Upper Curve
Equation
Time
-0.03
-0.85 T -0.68
sinπ/2
-0.68 T + 0.36
[1 + T/0.18]] -0.03
-0.68 T 0.36
-0.03
Equation
+0.03
0.5[ 1 +
sinπ/2
[1 +T/0.34]] +0.03
0.08+0.407e-1.84(T-0.36)
Table 4. DSX-3 Pulse Template Boundaries for Bellcore TR-NWT-000499 Standards (See Figure 4)
Rev. 2.01
8
XR-T7296
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
Normalized Amplitudes
Normalized Amplitudes
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.5
-01
0
0.5
1.0
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
1.2
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-1.0
1.5
-0.5
0
0.5
1.0
1.5
Time Slots-Normalized to Peak Location
Time Slots-Normalized to Peak Location
Figure 4. DSX-3 Isolated Pulse Template for
Bellcore TR-NWT-000499
Figure 3. DSX-3 Isolated Pulse Template for
ANSI T1.404 Standards
Parameter
Specification
STS-1 SIGNAL REQUIREMENTS
Line Rate
51.84Mbps
For STS-1 operation, the cross-connect is referred at the
STSX-1. Table 5 lists the signal requirements at the
STSX-1. Instead of the DS3 isolated pulse template, an
eye diagram mask is specified for STS-1 operation
(TA-TSY-000253). (See Figure 5).
Line Code
Bipolar with three-0 substitution (B3ZS)
Test Load
75 Ω 5%
Power Levels
A wide-band power level measurement
at the STSX-1 interface using a lowpass filter with a 3dB cutoff frequency
of at least 200MHz is within -2.7dBm
and 4.7dBm.
Table 5. STSX-1 Interconnection Specification
Figure 5. STSX-1 Isolated Pulse Template for Bellcore TA-TSY-000253
Rev. 2.01
9
1.28
1.07
0.86
0.65
0.45
-0.2
–1.01
0
0.24
0.2
0.03
0.4
–0.18
0.6
–0.38
0.3
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎ
–0.59
1
–0.80
Normalized Amplitude
1.2
XR-T7296
E3 SIGNAL REQUIREMENTS
The T7296 is designed to transmit pulses that conform to
CCITT recommendation G.703. Figure 6 shows the E3
pulse mask requirement recommended in G.703, and
Table 6 shows the pulse specifications.
17ns
(14.55 + 2.45)
V
0.2
0.1
1.0
0.1
0.2
8.65ns
(14.55 - 5.90)
Nominal pulse
14.55ns
0.5
12.1ns
(14.55 - 2.45)
0.1
0
24.5ns
(14.55 + 9.95)
0.1
0.1
0.1
0.2
29.1ns
(14.55 + 14.55)
CCITT-32581
Figure 6. CCITT G.703 Pulse Mark at the 34,368-kbit/s Interface
Parameter
Value
Pulse Shape (Nominally Rectangular)
All marks of a valid signal must conform with the mask (see Figure 6),
irrespective of the sign
Pair(s) In Each Direction
One coaxial pair
Test Load Impedance
75Ω resistive
Nominal Peak Voltage of a Mark (Pulse)
1.0V
Peak Voltage of a Space (No Pulse)
0V 0.1V
Nominal Pulse Width
14.55ns
Ratio of the Amplitudes of Positive and Negative Pulses at the Center of a Pulse
Interval
0.95 to 1.05
Ratio of the Widths of Positive and Negative Pulses at the Nominal Half Amplitude
0.95 to 1.05
Table 6. E3 Pulse Specifications
Rev. 2.01
10
XR-T7296
tR
tF
TCLK
tTHO
tTSU
TPDATA
OR
TNDATA
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
tTDY
TTIP
OR
TRING
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ
tR
tF
RCLK
tRHO
tRSU
RPDATA
OR
RNDATA
tF
tR
RCLKO
tRDY
RPOS/RNEG
OR
RNRZ
Figure 7. Timing Diagrams for System Interface
Rev. 2.01
11
XR-T7296
0
1
0
0
V
1
0
V
0
1
1
0
0
0
0
1
0
1
1
0
0
0
0
1
RPDATA
RNDATA
V
RPOS
RNEG
RNRZ
0
1
0
0
0
1
0
1
BPV
BPV
Corresponding
To Coding Rule
BPV Not
Corresponding
To Coding Rule
Coding
Error
Note
The delay from RPDATA/RNDATA to RPOS/RNEG/RNRZ is not shown here.
Figure 8. Bipolar Violation Example for B3ZS Mode
Rev. 2.01
12
XR-T7296
VCC
OUTPUTS
RECEIVER
MONITOR
RLOS
R I
E C
Q T
B
5 6 7 8
S1
SW DIP-4
RLOL
4 3 2 1
L
O
S
T
H
R
VCC
2 1 3 4 5 6 7 8
1 3 5 7
TP
TP
U1
XR-T7295
INPUT
SIGNAL
8
B1
C2
7
2
RIN
R2
U2
XR-T7296
2 4 6 8
LOSTHR
REQB
ICT/
RCLK
RNDATA
RPDATA
RLOL
RLOS
R22
22K
R21
22K
19
18
17
14
15
16
LLOOP
R7
R8
R10
39
39
39
1
28
27
RCLK
RNDATA
RPDATA
0.01µF
P2
75
EXTERNAL
CLOCK
B2
TMC1
3
1 1 1 1 1 1 1 9
5 64 3 2 1 0
R1
50
R5
50
RLOOP
DS3,STS-1/E3/
TAOS
ICT/
TXLEV
ENCODIS
DECODIS
4
R6
GNDA
LPF1
75
GNDC
C3
0.1µF
9
TCLK
BT1
RNRZ
V
D
D
D
1 1
2 1
8
TRING
B3
C6
7
TPDATA
TTIP
0.1µF
MRING
MTIP
GNDD
DMO
BPV
VCC RX
C7
RNEG
RECEIVER
OUTPUTS
14
RNRZ
+ E1
22µF
18
13
GNDA
DMO
R3
23
R15
270
36
B6
T1
20
R16
270
36
10
21
TRANSFORMER # PULSE ENGINEERING
PE 65966
PE 65967 IN SURFACE MOUNT
V
D
D
D
BT2
6
C8
0.1µF
P3
VCC TX
C9
FERRITE BEAD # FAIR RITE 2643000101
FERRITE BEAD
0.1µF
Figure 9. Evaluation System Schematic
Rev. 2.01
13
TTIP
TRING
PE65966
19
BPV
V
D
D
A
24
TRANSMITER
MONITOR
OUTPUTS
R4
22
TPDATA
P1
0.1µF
RPOS
15
TNDATA
FERRITE BEAD
C4
0.1µF
RCLKO
16
B4
TNDATA
20
TCLK
10
LPF2
V
D
D
C
RPOS
RNEG
GNDD
V
D
D
A
9
LLOOP
RLOOP
T3/E3
TAOS
TXLEV
ICT
ENCODIS
DECODIS
17
B5
9
5
7
8
RCLKO
1
16
15
14
13
12
11
10
SW DIP-8
6
EXCLK
S2
1
2
3
4
5
6
GND
TMC2
13
3
2
4
5
26
25
11
12
+E2
22µF
C5
0.1µF
XR-T7296
28 LEAD PLASTIC DUAL-IN-LINE
(600 MIL PDIP)
Rev. 1.00
28
15
E1
1
14
E
D
Seating
Plane
A2
A
L
A1
α
C
B
B1
e
INCHES
SYMBOL
eA
eB
MILLIMETERS
MIN
MAX
MIN
A
0.160
0.250
4.06
6.35
A1
0.015
0.070
0.38
1.78
A2
0.125
0.195
3.18
4.95
B
0.014
0.024
0.36
0.56
B1
0.030
0.070
0.76
1.78
C
0.008
0.014
0.20
0.38
D
1.380
1.565
35.05
39.75
E
0.600
0.625
15.24
15.88
E1
0.485
0.580
12.32
14.73
e
eA
0.100 BSC
0.600 BSC
MAX
2.54 BSC
15.24 BSC
eB
0.600
0.700
15.24
17.78
L
0.115
0.200
2.92
5.08
α
0°
15°
0°
Note: The control dimension is the inch column
15°
Rev. 2.01
14
XR-T7296
28 LEAD SMALL OUTLINE J LEAD
(300 MIL JEDEC SOJ)
Rev. 1.00
D
28
15
E
H
1
14
A2
A
Seating
Plane
C
B
e
R
A1
E1
INCHES
SYMBOL
MILLIMETERS
MIN
MAX
MIN
A
0.145
0.200
3.60
5.08
A1
0.025
–––
0.64
–––
A2
0.120
0.140
3.05
3.56
B
0.014
0.020
0.36
0.51
C
0.008
0.013
0.20
0.30
D
0.697
0.712
17.70
18.08
E
0.292
0.300
7.42
7.62
E1
0.262
0.272
6.65
6.91
e
0.050 BSC
MAX
1.27 BSC
H
0.335
0.347
8.51
8.81
R
0.030
0.040
0.76
1.02
Note: The control dimension is the inch column
Rev. 2.01
15
XR-T7296
NOTICE
EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are
free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary
depending upon a user’s specific application. While the information in this publication has been carefully checked;
no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or
malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly
affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation
receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the
user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances.
Copyright 1992 EXAR Corporation
Datasheet June 1997
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
Rev. 2.01
16