INTEL LXT381BE

LXT381
Octal E1 Line Interface Unit
Datasheet
General Description
The LXT381 is an octal short haul analog Line Interface Unit for ITU G.703 2.048 Mbit/sec.
transmission systems. It incorporates eight independent receivers and eight independent
transmitters in a single LQFP-144 or PBGA-160 package.
The transmit output drivers provide low impedance, constant during marks and spaces and
constant pulse amplitudes independent of supply voltage variations.
The LXT381 may be configured for unbalanced 75Ω or for balanced 120Ω systems without
external component changes in the transmit section. The transmit return loss performance
exceeds latest ETSI return loss recommendations such as ETS 300166.
The LXT381 features a differential data receiver architecture with high noise interference
margin. The receivers use peak detection and a variable threshold for reliable data recovery
down to 500 mV or up to 12 dB of cable attenuation.
Each receiver incorporates an analog Loss Of Signal (LOS) processor that meets latest ITU
G.775 standard.
The fast power down mode of all transmitters allows the implementation of Hitless Protection
Switching (HPS) application without the use of relays.
Applications
■
Synchronous Digital Hierarchy (SDH) E1 tributary interfaces
■
Public switching trunk line interfaces
Digital Access Cross Connects (DACS)
Microwave transmission systems
■
■
Product Features
■
■
■
■
■
■
Octal E1 short haul line interface per ITU
G.703
Single rail supply voltage of 3.3V with 5V
I/O capability
Low power consumption of <100 mW per
channel (typ.)
75Ω/120Ω TX operation without
component changes
Transmit return loss complies with ETSI
ETS 300 166
Hitless Protection Switching (HPS)
■
■
■
■
■
■
■
Driver short circuit current limiter (<50 mA
RMS)
Differential receiver with 15dB of signal to
noise interference margin
Data recovery with no need for external
reference clock
Analog LOS detection per ITU G.775
Simple hardware control mode
JTAG Boundary Scan test port per IEEE
1149.4
Small footprint 144 pin LQFP or 160 pin
PBGA package
As of January 15, 2001, this document replaces the Level One document
known as Octal E1 Line Interface.
Order Number: 249005-001
January 2001
Information in this document is provided in connection with Intel® products. No license, express or implied, by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability
whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to
fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not
intended for use in medical, life saving, or life sustaining applications.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for
future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
The LXT381 may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current
characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800548-4725 or by visiting Intel’s website at http://www.intel.com.
Copyright © Intel Corporation, 2001
*Third-party brands and names are the property of their respective owners.
Datasheet
Octal E1 Line Interface Unit — LXT381
Contents
1.0
Pin Assignments and Signal Descriptions ...................................................... 5
2.0
Functional Description...........................................................................................13
2.1
2.2
2.3
2.4
2.5
2.6
3.0
Receiver ..............................................................................................................13
2.1.1 Loss Of Signal Detector .........................................................................13
Transmitter ..........................................................................................................13
2.2.1 Transmit Pulse Shaping .........................................................................14
Interfacing with 5V logic ......................................................................................14
Line Protection ....................................................................................................14
Loopbacks ...........................................................................................................14
2.5.1 Analog Loopback....................................................................................15
2.5.2 Remote Loopback ..................................................................................15
Hitless Protection Switching (HPS) .....................................................................15
JTAG Boundary Scan .............................................................................................18
3.1
3.2
3.3
Overview .............................................................................................................18
Architecture .........................................................................................................18
3.2.1 TAP Controller........................................................................................19
JTAG Register Description..................................................................................20
3.3.1 Boundary Scan Register (BSR)..............................................................21
3.3.2 Device Identification Register (IDR) .......................................................24
3.3.3 Bypass Register (BYR) ..........................................................................24
3.3.4 Analog Port Scan Register (ASR) ..........................................................24
3.3.5 Instruction Register (IR) .........................................................................25
4.0
Test Specifications ..................................................................................................27
5.0
Mechanical Specifications....................................................................................34
Datasheet
3
LXT381 — Octal E1 Line Interface Unit
Figures
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LXT381 144-Pin Low-Profile Quad Flat Package (LQFP) Pin Assignments and
Package Markings5
LXT381 160-Pin Plastic Ball Grid Array (PBGA) Pin Assignments ....................... 6
Analog Loopback ................................................................................................ 15
Remote Looback ................................................................................................. 15
External Transmit/Receive Line Circuitry ........................................................... 17
LXT381 JTAG Architecture ................................................................................. 18
JTAG State Diagram ........................................................................................... 20
Analog Test Port Application.............................................................................. 26
Transmit Clock Timing ........................................................................................ 30
Receive Timing Diagram..................................................................................... 31
JTAG Timing ....................................................................................................... 31
E1 Mask Templates ............................................................................................ 33
LXT381 144 Pin LQFP Package Dimensions ..................................................... 34
LXT381 160 Pin PBGA Package Dimensions..................................................... 35
1
2
3
4
5
6
7
8
9
11
10
12
13
14
15
16
17
18
LXT381 Pin Description ........................................................................................ 7
Operation Mode Summary .................................................................................. 16
TAP State Description......................................................................................... 19
Boundary Scan Register (BSR) .......................................................................... 21
Device Identification Register (IDR) .................................................................... 24
Analog Port Scan Register (ASR) ....................................................................... 24
Instruction Register (IR) ...................................................................................... 26
Absolute Maximum Ratings ................................................................................ 27
Recommended Operating Conditions ................................................................. 27
Transmit Transmission Characteristics ............................................................... 28
DC Characteristics .............................................................................................. 28
Receive Transmission Characteristics ................................................................ 29
Analog Test Port Characteristics......................................................................... 30
Transmit Timing Characteristics.......................................................................... 30
Receive Timing Characteristics........................................................................... 30
JTAG Timing Characteristics .............................................................................. 31
Transformer Specifications ................................................................................. 32
G.703 2.048 Mbit/s Pulse Mask Specifications ................................................... 32
Tables
4
Datasheet
Octal E1 Line Interface — LXT381
1.0
Pin Assignments and Signal Descriptions
144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
TNEG7
RCLK7
RPOS7
RNEG7
ALOS7
RTIP7
RRING7
TVCC7
TTIP7
TRING7
TGND7
RRING6
RTIP6
TGND6
TRING6
TTIP6
TVCC6
RTIP5
RRING5
TVCC5
TTIP5
TRING5
TGND5
RRING4
RTIP4
TGND4
TRING4
TTIP4
TVCC4
RPOL
OE
ALOS4
RNEG4
RPOS4
RCLK4
TNEG4
Figure 1. LXT381 144-Pin Low-Profile Quad Flat Package (LQFP) Pin Assignments and
Package Markings
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
Part #
LOT #
FPO #
LXT381LE XX
XXXXXX
XXXXXXXX
Rev #
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
TPOS4
TCLK4
ALOS5
RNEG5
RPOS5
RCLK5
TNEG5
TPOS5
TCLK5
TDI
TDO
TCK
TMS
TRST
AT1
AT2
VCCIO1
GNDIO1
VCC1
GND1
GND
GND
GND
GND
GND
NC
NC
TCLK2
TPOS2
TNEG2
RCLK2
RPOS2
RNEG2
ALOS2
TCLK3
TPOS3
TPOS0
TNEG0
RCLK0
RPOS0
RNEG0
ALOS0
GND
TVCC0
TTIP0
TRING0
TGND0
RTIP0
RRING0
TGND1
TRING1
TTIP1
TVCC1
RRING1
RTIP1
TVCC2
TTIP2
TRING2
TGND2
RTIP2
RRING2
TGND3
TRING3
TTIP3
TVCC3
RRING3
RTIP3
ALOS3
RNEG3
RPOS3
RCLK3
TNEG3
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
TPOS7
TCLK7
ALOS6
RNEG6
RPOS6
RCLK6
TNEG6
TPOS6
TCLK6
RPD
GND
GND
GND
GND
GND
GND
VCCIO0
GNDIO0
VCC0
GND0
LOOP0
LOOP1
LOOP2
LOOP3
LOOP4
LOOP5
LOOP6
LOOP7
TCLK1
TPOS1
TNEG1
RCLK1
RPOS1
RNEG1
ALOS1
TCLK0
Package Topside Markings
Marking
Definition
Part #
Unique identifier for this product family.
Rev #
Identifies the particular silicon “stepping” — refer to the specification update for additional stepping
information.
Lot #
Identifies the batch.
FPO #
Datasheet
Identifies the Finish Process Order.
5
LXT381 — Octal E1 Line Interface
Figure 2. LXT381 160-Pin Plastic Ball Grid Array (PBGA) Pin Assignments
6
14
13
12
11
10
9
8
7
6
5
4
3
2
1
A
RCLK
4
RPOS
4
RNEG
4
TVCC
4
TRING
4
TGND
4
RTIP
4
RTIP
7
TGND
7
TRING
7
TVCC
7
RNEG
7
RPOS
7
RCLK
7
A
B
TCLK
4
TPOS
4
TNEG
4
TVCC
4
TTIP
4
TGND
4
RRING
4
RRING
7
TGND
7
TTIP
7
TVCC
7
TNEG
7
TPOS
7
TCLK
7
B
C
RCLK
5
RPOS
5
RNEG
5
TVCC
5
TRING
5
TGND
5
RTIP
5
RTIP
6
TGND
6
TRING
6
TVCC
6
RNEG
6
RPOS
6
RCLK
6
C
D
TCLK
5
TPOS
5
TNEG
5
TVCC
5
TTIP
5
TGND
5
RRING
RRING
5
6
TGND
6
TTIP
6
TVCC
6
TNEG
6
TPOS
6
TCLK
6
D
E
OE
RPOL
ALOS
5
ALOS
4
ALOS
7
ALOS
6
GND
RPD
E
F
TCK
TDO
TDI
TMS
GND
GND
GND
GND
F
G
VCCIO
1
AT
2
TRST
GNDIO
1
GND
LOOP
0
VCCIO
0
G
H
VCC
1
AT
1
GND
GND
1
GND
0
LOOP
1
LOOP
2
VCC
0
H
J
GND
GND
GND
GND
LOOP
3
LOOP
4
LOOP
5
LOOP
6
J
K
N/C
N/C
ALOS
2
ALOS
3
ALOS
0
ALOS
1
GND
LOOP
7
K
L
TCLK
2
TPOS
2
TNEG
2
TVCC
2
TTIP
2
TGND
2
RRING
RRING
2
1
TGND
1
TTIP
1
TVCC
1
TNEG
1
TPOS
1
TCLK
1
L
M
RCLK
2
RPOS
2
RNEG
2
TVCC
2
TRING
2
TGND
2
RTIP
2
RTIP
1
TGND
1
TRING
1
TVCC
1
RNEG
1
RPOS
1
RCLK
1
M
N
TCLK
3
TPOS
3
TNEG
3
TVCC
3
TTIP
3
TGND
3
RRING
RRING
3
0
TGND
0
TTIP
0
TVCC
0
TNEG
0
TPOS
0
TCLK
0
N
P
RCLK
3
RPOS
3
RNEG
3
TVCC
3
TRING
3
TGND
3
RTIP
3
RTIP
0
TGND
0
TRING
0
TVCC
0
RNEG
0
RPOS
0
RCLK
0
P
14
13
12
11
10
9
8
7
6
5
4
3
2
1
GNDIO
0
LXT381BE
(Bottom View)
Datasheet
Octal E1 Line Interface — LXT381
Table 1.
LXT381 Pin Description
Pin #
LQFP
Pin #
PBGA
Symbol
I/O1
1
B2
TPOS7
DI
Description
Transmit Positive Data Input.
Transmit Clock Input.
When TCLK is active, TPOS and TNEG work as NRZ inputs. TPOS and
TNEG are sampled on the falling edge of TCLK.
2
B1
TCLK7
DI
If TCLK is held High, TPOS and TNEG work as RZ inputs. In this mode,
pulse widths are determined by TPOS and TNEG duty cycles. An analog
timer is used to determine if TCLK is high for at least 12 µ seconds in order
to enable the above function.
If TCLK is held Low, the output drivers enter a low power high Z mode.
TCLK Operating Mode
Clocked NRZ
H
RZ
L
Driver Tri-State
3
E3
ALOS6
DO
Analog Loss of Signal Output. Please refer to the ALOS functional
description.
Receive Negative Data Output.
Receive Positive Data Output.
4
C3
RNEG6
DO
5
C2
RPOS6
DO
These pins act as RZ data receiver outputs. The output polarity is
selectable with RPOL The pins will be active High polarity when RPOL is
High and Active Low Polarity when RPOL is Low.
RPOS and RNEG will be active when the corresponding transceiver is in
LOS.
RPOS and RNEG will be in high impedance state if the RPD pin is Low.
6
C1
RCLK6
DO
Receive Clock Output. RPOS and RNEG are internally connected to an
EXOR that is fed to the RCLK output for external clock recovery
applications. RCLK will be in high impedance state if the RPD pin is Low.
Transmit Negative Data Input.
Transmit Positive Data Input.
When TCLK is active, TPOS/TNEG are active high NRZ inputs. TPOS
indicates the transmission of a positive pulse whereas TNEG indicates the
transmission of a negative pulse. TPOS and TNEG are sampled on the
falling edge of TCLK.
7
D3
TNEG6
DI
8
D2
TPOS6
DI
If TCLK is held High, TPOS and TNEG work as RZ inputs. In this mode,
pulse widths are determined by TPOS and TNEG duty cycles. An analog
timer is used to determine if TCLK is high for at least 12 µ seconds in order
to enable the above function.
TCLK TPOS/TNEG Operating Mode
Clocked NRZ
H
RZ
9
D1
TCLK6
DI
Transmit Clock Input.
10
E1
RPD
DI
Receiver Power Down Input. If RPD is Low, the complete receive path is
powered down and the output pins RCLK, RPOS and RNEG are switched
to Tri-state mode.
11
E2
GND
S
Ground. This pin must be connected to Ground.
12
F1
GND
S
Ground. This pin must be connected to Ground.
13
F2
GND
S
Ground. This pin must be connected to Ground.
1. DI: Digital Input; DO: Digital Output; DI/O: Digital Bidirectional Port; AI: Analog Input; AO: Analog Output S: Power Supply;
N.C.: Not
Connected.
Datasheet
7
LXT381 — Octal E1 Line Interface
Table 1.
LXT381 Pin Description (Continued)
Pin #
LQFP
Pin #
PBGA
Symbol
I/O1
14
F3
GND
S
Ground. This pin must be connected to Ground.
Description
15
F4
GND
S
Ground. This pin must be connected to Ground.
16
G3
GND
S
Ground. This pin must be connected to Ground.
17
G1
VCCIO0
S
Power (I/O).
18
G4
GNDIO0
S
Ground (I/O).
19
H1
VCC0
S
Power (Core).
20
H4
GND0
S
Ground (Core).
Loopback Mode Select/Parallel Databus Input & Output. These pins
are inputs that select the loopback mode for transceiver ports 0-7
respectively as follows:
Normal operation (no loopback) is selected when pin is left open
(unconnected).
21
G2
LOOP0
DI
22
H3
LOOP1
DI
23
H2
LOOP2
DI
24
J4
LOOP3
DI
25
J3
LOOP4
DI
26
J2
LOOP5
DI
27
J1
LOOP6
DI
28
K1
LOOP7
DI
29
L1
TCLK1
DI
Transmit Clock Input.
30
L2
TPOS1
DI
Transmit Positive Data Input.
31
L3
TNEG1
DI
Transmit Negative Data Input.
32
M1
RCLK1
DO
Receive Clock Output.
33
M2
RPOS1
DO
Receive Positive Data Output.
34
M3
RNEG1
DO
Receive Negative Data Output.
35
K3
ALOS1
DO
Analog Loss of Signal Output.
36
N1
TCLK0
DI
Transmit Clock Input.
37
N2
TPOS0
DI
Transmit Positive Data Input.
38
N3
TNEG0
DI
Transmit Negative Data Input.
39
P1
RCLK0
DO
Receive Clock Output.
40
P2
RPOS0
DO
Receive Positive Data.
41
P3
RNEG0
DO
Receive Negative Data.
42
K4
ALOS0
DO
Analog Loss of Signal Output.
43
K2
GND
S
Ground. This pin must be connected to Ground.
44
N4, P4
TVCC0
S
Transmit Driver Power Supply. Power supply pin for the output driver.
Remote loopback mode is selected when pin is Low. In this mode, data on
TPOS and TNEG is ignored and data received on RTIP and RRING is
looped around and retransmitted on TTIP and TRING.
Analog local loopback mode is selected when pin is High. In this mode,
data received on RTIP and RRING is ignored and data transmitted on TTIP
and TRING is internally looped around and routed back to the receive
inputs.
Note: When these inputs are left open, they stay in a high impedance
state. Therefore, the layout design should not route signals with fast
transitions near the LOOP pins. This practice will minimize
capacitive coupling.
1. DI: Digital Input; DO: Digital Output; DI/O: Digital Bidirectional Port; AI: Analog Input; AO: Analog Output S: Power Supply;
N.C.: Not
Connected.
8
Datasheet
Octal E1 Line Interface — LXT381
Table 1.
Pin #
LQFP
LXT381 Pin Description (Continued)
Pin #
PBGA
Symbol
I/O1
Description
Transmit Tip Output.
Transmit Ring Output.
45
N5
TTIP0
AO
46
P5
TRING0
AO
47
N6, P6
TGND0
S
48
P7
RTIP0
AI
Receive Ring Input.
49
N7
RRING0
AI
These pins are the inputs to the differential line receiver. Data is recovered
and output on the RPOS/RNEG pins.
50
L6, M6
TGND1
S
Transmit Driver Ground.
51
M5
TRING1
AO
Transmit Ring Output.
52
L5
TTIP1
AO
Transmit Tip Output.
53
L4, M4
TVCC1
S
Transmit Driver Power Supply. Power supply pin for the output driver.
54
L7
RRING1
AI
Receive Ring Input.
55
M7
RTIP1
AI
Receive Tip Input.
56
L11, M11
TVCC2
S
Transmit Driver Power Supply.
These pins are differential line driver outputs designed to drive 75 Ω
unbalanced or 120 Ω balanced cables with a 1:2 transformer and two 11 Ω
series resistors. TRING and TTIP will be in high impedance state if the
TCLK pin is Low.
Transmit Driver Ground. Ground pin for the output driver.
Receive TIP Input.
57
L10
TTIP2
AO
Transmit Tip Output.
58
M10
TRING2
AO
Transmit Ring Output.
59
L9, M9
TGND2
S
Transmit Driver Ground.
60
M8
RTIP2
AI
Receive TIP Input.
61
L8
RRING2
AI
Receive Ring Input.
62
N9, P9
TGND3
S
Transmit Driver Ground. Ground pin for the output driver.
63
P10
TRING3
AO
Transmit Ring.
64
N10
TTIP3
AO
Transmit Tip Output.
65
N11, P11
TVCC3
S
Transmit Driver Power Supply. Power supply pin for the output driver.
66
N8
RRING3
AI
Receive Ring Input.
67
P8
RTIP3
AI
Receive Tip Input.
68
K11
ALOS3
DO
Analog Loss of Signal Output.
69
P12
RNEG3
DO
Receive Negative Data Output.
70
P13
RPOS3
DO
Receive Positive Data Output.
71
P14
RCLK3
DO
Receive Clock Output.
72
N12
TNEG3
DI
Transmit Negative Data Input.
73
N13
TPOS3
DI
Transmit Positive Data Input.
74
N14
TCLK3
DI
Transmit Clock Input.
75
K12
ALOS2
DO
Analog Loss of Signal Output.
76
M12
RNEG2
DO
Receive Negative Data Output.
77
M13
RPOS2
DO
Receive Positive Data Output.
1. DI: Digital Input; DO: Digital Output; DI/O: Digital Bidirectional Port; AI: Analog Input; AO: Analog Output S: Power Supply;
N.C.: Not
Connected.
Datasheet
9
LXT381 — Octal E1 Line Interface
Table 1.
LXT381 Pin Description (Continued)
Pin #
LQFP
Pin #
PBGA
Symbol
I/O1
78
M14
RCLK2
DO
Receive Clock Output.
79
L12
TNEG2
DI
Transmit Negative Data Input.
80
L13
TPOS2
DI
Transmit Positive Data Input.
81
L14
TCLK2
DI
Transmit Clock Input.
82
K13
NC
NC
Not Connected. This pin must be left open for normal operation.
83
K14
NC
NC
Not Connected. This pin must be left open for normal operation.
84
J11
GND
S
Ground. This pin must be connected to Ground.
85
J12
GND
S
Ground. This pin must be connected to Ground.
86
J13
GND
S
Ground. This pin must be connected to Ground.
87
J14
GND
S
Ground. This pin must be connected to Ground.
88
H12
GND
S
Ground. This pin must be connected to Ground.
89
H11
GND1
S
Ground (Core).
90
H14
VCC1
S
Power (Core).
91
G11
GNDIO1
S
Ground (I/O).
92
G14
VCCIO1
S
Power (I/O).
93
G13
AT2
AO
JTAG Analog Output Test Port 2.
94
H13
AT1
AI
JTAG Analog Input Test Port 1.
95
G12
TRST
DI
JTAG Controller Reset Input. Input is used to reset JTAG controller.
TRST is pulled up internally and may be left disconnected.
96
F11
TMS
DI
JTAG Test Mode Select Input. Used to control the test logic state
machine. Sampled on rising edge of TCK. TMS is pulled up internally and
may be left disconnected.
97
F14
TCK
DI
JTAG Clock Input. Clock input for JTAG. Connect to GND when not used.
98
F13
TDO
DO
JTAG Data Output. Test Data Output for JTAG. Used for reading all serial
configuration and test data from internal test logic. Updated on falling edge
of TCK.
99
F12
TDI
DI
JTAG Data Input. Test Data input for JTAG. Used for loading serial
instructions and data into internal test logic. Sampled on rising edge of
TCK. TDI is pulled up internally and may be left disconnected.
100
D14
TCLK5
DI
Transmit Clock Input.
101
D13
TPOS5
DI
Transmit Positive Data Input.
102
D12
TNEG5
DI
Transmit Negative Data Input.
103
C14
RCLK5
DO
Receive Clock Output.
104
C13
RPOS5
DO
Receive Positive Data Output.
105
C12
RNEG5
DO
Receive Negative Data Output.
106
E12
ALOS5
DO
Analog Loss of Signal Output.
107
B14
TCLK4
DI
Transmit Clock Input.
Description
1. DI: Digital Input; DO: Digital Output; DI/O: Digital Bidirectional Port; AI: Analog Input; AO: Analog Output S: Power Supply;
N.C.: Not
Connected.
10
Datasheet
Octal E1 Line Interface — LXT381
Table 1.
LXT381 Pin Description (Continued)
Pin #
LQFP
Pin #
PBGA
108
109
Symbol
I/O1
B13
TPOS4
DI
Transmit Positive Data Input.
B12
TNEG4
DI
Transmit Negative Data Input.
Description
110
A14
RCLK4
DO
Receive Clock Output.
111
A13
RPOS4
DO
Receive Positive Data Output.
112
A12
RNEG4
DO
Receive Negative Data Output.
113
E11
ALOS4
DO
Analog Loss of Signal Output.
Output Driver Enable Input.
If this pin is asserted Low all analog driver outputs immediately enter a high
impedance mode to support redundancy applications without external
mechanical relays. All other internal circuitry stays active.
114
E14
OE
DI
115
E13
RPOL
DI
Receive Polarity Select Input. Determines RPOS/RNEG polarity.
RPOS/RNEG are active High output polarity when RPOL is High and
active Low polarity when RPOL is Low.
116
A11, B11
TVCC4
S
Transmit Driver Power Supply. Power supply pin for the output driver.
117
B10
TTIP4
AO
Transmit Tip Output.
118
A10
TRING4
AO
Transmit Ring Output.
119
A9, B9
TGND4
S
Transmit Driver Ground. Ground pin for the output driver.
120
A8
RTIP4
AI
Receive Tip Input.
121
B8
RRING4
AI
Receive Ring Input.
122
C9, D9
TGND5
S
Transmit Driver Ground. Ground pin for the output driver.
123
C10
TRING5
AO
Transmit Ring Output.
124
D10
TTIP5
AO
Transmit Tip Output.
125
C11, D11
TVCC5
S
Transmit Driver Power Supply. Power supply pin for the output driver.
126
D8
RRING5
AI
Receive Ring Input.
127
C8
RTIP5
AI
Receive Tip Input.
128
C4, D4
TVCC6
S
Transmit Driver Power Supply. Power supply pin for the output driver.
129
D5
TTIP6
AO
Transmit Tip Output.
130
C5
TRING6
AO
Transmit Ring Output.
131
C6, D6
TGND6
S
Transmit Driver Ground. Ground pin for the output driver.
132
D7
RRING6
AI
Receive Ring Input.
133
C7
RTIP6
AI
Receive Tip Input.
134
A6, B6
TGND7
S
Transmit Driver Ground. Ground pins for the output driver.
135
B5
TTIP7
AO
Transmit Tip Output.
136
A5
TRING7
AO
Transmit Ring Output.
137
A4, B4
TVCC7
S
Transmit Driver Power Supply. Power supply pin for the output driver.
138
B7
RRING7
AI
Receive Ring Input.
139
A7
RTIP7
AI
Receive Tip Input.
140
E4
ALOS7
DO
Analog Loss of Signal Output.
1. DI: Digital Input; DO: Digital Output; DI/O: Digital Bidirectional Port; AI: Analog Input; AO: Analog Output S: Power Supply;
N.C.: Not
Connected.
Datasheet
11
LXT381 — Octal E1 Line Interface
Table 1.
LXT381 Pin Description (Continued)
Pin #
LQFP
Pin #
PBGA
Symbol
I/O1
141
A3
RNEG7
DO
Receive Negative Data Output.
142
A2
RPOS7
DO
Receive Positive Data Output.
143
A1
RCLK7
DO
Receive Clock Output.
144
B3
TNEG7
DI
Transmit Negative Data Input.
Description
1. DI: Digital Input; DO: Digital Output; DI/O: Digital Bidirectional Port; AI: Analog Input; AO: Analog Output S: Power Supply;
N.C.: Not
Connected.
12
Datasheet
Octal E1 Line Interface — LXT381
2.0
Functional Description
The LXT381 is a fully integrated octal line interface unit designed for G.703 2.048 Mbps
applications. Each transceiver front end interfaces with four lines, one pair for transmit, one pair
for receive. These two lines comprise a digital data loop for full duplex transmission. The LXT381
is designed to operate as an analog front-end (line driver and data recovery) without any reference
clock.
2.1
Receiver
The eight receivers in the LXT381 are identical. The following paragraphs describe the operation
of a single receiver.
The receive signal is input to the LIU via a 1:1 transformer. See Figure 5. A peak detector samples
the received signal and determines its maximum value. A percentage of the peak value is provided
to the data slicers to ensure optimum signal-to-noise ratio.
The receiver is capable of accurately recovering signals with up to 12dB of attenuation (from 2.37
V nominal), corresponding to a received signal level of approximately 500 mV. Regardless of
received signal level, the peak detectors are held above a minimum level of 150 mV to provide
immunity from impulsive noise. After processing through the data slicers, the received signal is
routed to the data ports and to the receive monitor.
Recovered data is output at RPOS and RNEG. RPOS/RNEG polarity is determined by the RPOL
pin. In addition, RPOS and RNEG are internally connected to an EXOR that is fed to the RCLK
output for external clock recovery applications.
The receivers in the LXT381 can be powered down using the RPD pin. In this case, the receiver
outputs RCLK/RPOS/RNEG will be in a high impedance state.
2.1.1
Loss Of Signal Detector
The LXT381 includes an analog LOS detector (ALOS pins) compliant with ITU-G.775
recommendation. The LXT381 monitors the incoming signal amplitude. Any signal below 200mV
for more than 30µs (typ) will assert the corresponding ALOS pin. The LOS condition is cleared
when the signal amplitude rises above 250mV. The LXT381 requires more than 10 and less than
255 bit periods to declare a LOS condition in accordance to ITU G.775.
During the LOS condition, the receiver outputs (RPOS and RNEG) will be held high.
2.2
Transmitter
The eight low power transmitters of the LXT381 are identical.
The LXT381 transmitters can work either with NRZ or RZ formatted signals, depending on the
TCLK state. See Table 2. When TCLK is active, NRZ data applied to TPOS/TNEG is clocked
serially into the device. The TPOS/TNEG inputs are sampled on the falling edge of TCLK.
Datasheet
13
LXT381 — Octal E1 Line Interface
When TCLK is held high for at least 12 µs, TPOS and TNEG become RZ formatted inputs. In this
mode, TPOS and TNEG control the pulse width and polarity on TTIP and TRING.
If TCLK is held Low, the output drivers enter a low power, high impedance mode. The OE pin can also
be used to set all the output drivers to an high impedance mode. This feature is useful for
redundancy/protection applications.
Each output driver is supplied by a separate power supply (TVCC and TGND).
2.2.1
Transmit Pulse Shaping
In NRZ mode, the transmitted pulse shape is internally generated using a high speed D/A
converter. Shaped pulses are further applied to the line driver for transmission onto the line at TTIP
and TRING. The line driver provides a constant low output impedance regardless of whether it is
driving marks, spaces or if it is in transition. This well controlled dynamic impedance provides
excellent return loss when used with external precision resistors (± 1% accuracy) in series with the
transformer. See Figure 5.
The LXT381 produces 2.048 MHz pulses for both 75 Ω coaxial (2.37 V) or 120 Ω shielded
twisted-pair (3.0 V) lines through an output transformer with a 1:2 step up pulse transformer and 11
Ω series resistors. No transmit component changes are required in 75 or 120 Ω operation as the
output driver dynamically adjusts its output pulse amplitude.
2.3
Interfacing with 5V logic
The LXT381 can interface with 5V logic. In this case, the VCCIO pins should be connected to a
5V power supply. The VCCIO pins feed the digital I/O pads making the input/output voltage levels
consistent with 5V logic. See Table 10. The internal logic will still operate from the 3.3V supply
(VCC0 and VCC1) to minimize the power consumption.
2.4
Line Protection
In the receive side, the 1 kΩ series resistors protect the receiver against current surges coupled into
the device. Due to the high receiver impedance (70 kΩ typ.) the resistors do not affect the receiver
sensitivity. In the transmit side, the Schottky diodes D1-D4 protect the output driver.While not
mandatory for normal operation, these protection elements are strongly recommended to improve
the design robustness.
2.5
Loopbacks
The LXT381 offers two loopback modes for diagnostic purposes. The loopback mode is selected
with the LOOPn pins.
14
Datasheet
Octal E1 Line Interface — LXT381
2.5.1
Analog Loopback
When selected, the transmitter outputs (TTIP & TRING) are connected internally to the receiver
inputs (RTIP & RRING) as shown in Figure 3. Data and clock are output at RCLK, RPOS &
RNEG pins for the corresponding transceiver. Note: Signals on the RTIP & RRING pins are
ignored during analog loopback.
2.5.2
Remote Loopback
Figure 3. Analog Loopback
TCLK
TPOS
TNEG
Buffer/
Pulse
Shaper
RCLK
RPOS
RNEG
Data
Recovery
TTIP
TRING
RTIP
RRING
During remote loopback, the RCLK, RPOS & RNEG outputs routed to the transmit circuits and
output on the TTIP & TRING pins. Signals on the TCLK, TPOS & TNEG pins are ignored during
remote loopback. See Figure 4. Note: because in a remote loopback, the RPOS/RNEG outputs
determine the transmitter pulse width, the G.703 pulse template may not be met in this test mode.
Figure 4. Remote Looback
2.6
TCLK
TPOS
TNEG
Buffer/
Pulse
Shaper
RCLK
RPOS
RNEG
Data
Recovery
TTIP
TRING
RTIP
RRING
Hitless Protection Switching (HPS)
The LXT386 transceivers include an output driver tristatability feature for T1/E1 redundancy
applications. This feature greatly reduces the cost of implementing redundancy protection by
eliminating external relays. Please refer to Application Note 119 for guidelines for implementing
redundancy systems for both T1 and E1 operation using the LXT380/1/4/6.
Datasheet
15
LXT381 — Octal E1 Line Interface
Table 2.
Operation Mode Summary
RPD
TCLK
Receive Mode
Transmit Mode
L
Clocked
Power Down
NRZ
L
L
Power Down
Power Down1
L
H
Power Down
RZ
H
Clocked
Data Recovery
NRZ
H
L
Data Recovery
Power down1
H
H
Data Recovery
RZ
1. In Remote loopback the driver will not power down.
16
Datasheet
Octal E1 Line Interface — LXT381
Figure 5. External Transmit/Receive Line Circuitry
3.3V
68µF
3.3V
TVS1
1
0.1µF
TVCC
TGND
TVCC
3
1:2
RT
D4
TTIP
D3
3.3V
TVCC
0.1µF
Tx LINE
2
560pF
VCC
D2
GND
TRING
RT
D1
LXT381
(ONE CHANNEL)
3
1:1
1kΩ
RTIP
RR
Rx LINE
0.22µF
RR
RRING
1kΩ
APPLICATION
COMPONENT
75Ω COAX
RT
11 Ω ±1%
11 Ω ±1%
RR
37.5 Ω ±1%
60 Ω ±1%
D1 - D4
INTERNATIONAL RECTIFIER
11DQ04 or 10BQ060
MOTOROLA
TVS1
Datasheet
120Ω TWISTED PAIR
MBR0540T1
SGS-THOMSON
SMLVT 3V3 3.3V
1
Common decoupling capacitor for all TVCC and TGND pins.
2
Typical value. Adjust for actual board parasitics to obtain optimum return loss.
3
Transformer turns ratio tolerance is ± 2%. See Test Specifications Section for transformer specifications.
17
LXT381 — Octal E1 Line Interface
3.0
JTAG Boundary Scan
3.1
Overview
The LXT381 supports IEEE 1149.1 compliant JTAG boundary scan. Boundary scan allows easy
access to the interface pins for board testing purposes.
In addition to the traditional IEE1149.1 digital boundary scan capabilities, the LXT381 also
includes analog test port capabilities. This feature provides access to the TIP and RING signals in
each channel (transmit and receive.) This way, the signal path integrity across the primary winding
of each coupling transformer can be tested.
3.2
Architecture
Figure 6 represents the LXT381 basic JTAG architecture.
The LXT381 JTAG architecture includes a TAP Test Access Port Controller, data registers and an
instruction register. The following paragraphs describe these blocks in detail.
Figure 6. LXT381 JTAG Architecture
Boundry Scan Data Register
BSR
Analog Port Scan Register
ASR
TDI
Device Identification Register
IDR
MUX
TDO
Bypass Register
BYR
Instruction Register
IR
TCK
TMS
TAP
Controller
TRST
18
Datasheet
Octal E1 Line Interface — LXT381
3.2.1
TAP Controller
The TAP controller is a 16 state synchronous state machine controlled by the TMS input and
clocked by TCK. See Figure 7. The TAP controls whether the LXT381 is in reset mode, receiving
an instruction, receiving data, transmitting data or in an idle state. Table 3 describes in detail each
of the states represented in Figure 7.
Table 3.
TAP State Description
State
Description
Test logic reset
In this state the test logic is disabled. The device is set to normal operation mode. While in this state, the
instruction register is set to the ICODE instruction.
Run -test/idle
The TAP controller stays in this state as long as TMS is low. Used to perform tests.
Capture - DR
The Boundary Scan Data Register (BSR) is loaded with input pin data.
Shift - DR
Shifts the selected test data registers by one stage toward its serial output.
Update - DR
Data is latched into the parallel output of the BSR when selected.
Capture - IR
Used to load the instruction register with a fixed instruction.
Shift - IR
Shifts the instruction register by one stage.
Update - IR
Loads a new instruction into the instruction register.
Pause - IR
Pause - DR
Momentarily pauses shifting of data through the data/instruction registers.
Exit1 - IR
Exit1 - DR
Exit2 - IR
Exit2 - DR
Temporary states that can be used to terminate the scanning process.
Datasheet
19
LXT381 — Octal E1 Line Interface
Figure 7. JTAG State Diagram
1
TEST-LOGIC
RESET
0
0
RUN TEST/IDLE
1
SELECT-DR
1
SELECT-IR
0
1
0
1
CAPTURE-DR
CAPTURE-IR
0
0
0
0
SHIFT-DR
SHIFT-IR
1
1
EXIT1-DR
1
1
EXIT1-IR
0
0
0
0
PAUSE-DR
PAUSE-IR
1
0
1
EXIT2-DR
0
EXIT2-IR
1
0
UPDATE-DR
1
3.3
1
0
UPDATE-IR
1
0
JTAG Register Description
The following paragraphs describe each of the registers represented in Figure 6.
20
Datasheet
Octal E1 Line Interface — LXT381
3.3.1
Boundary Scan Register (BSR)
The BSR is a shift register that provides access to all the digital I/O pins. The BSR is used to apply
and read test patterns to/from the board. Each pin is associated with a scan cell in the BSR register.
Bidirectional pins or tristatable pins require more than one position in the register. Table 4 shows
the BSR scan cells and their functions. Data into the BSR is shifted in LSB first
.
Table 4.
Boundary Scan Register (BSR)
Bit #
Pin
Signal
I/O
Type
Bit
Symbol
0
LOOP0
I/O
PDO0
1
LOOP0
I/O
PADD0
2
LOOP1
I/O
PDO1
3
LOOP1
I/O
PADI1
4
LOOP2
I/O
PDO2
5
LOOP2
I/O
PADI2
6
LOOP3
I/O
PDO3
7
LOOP3
I/O
PADI3
8
LOOP4
I/O
PDO4
9
LOOP4
I/O
PADI4
10
LOOP5
I/O
PDO5
11
LOOP5
I/O
PADI5
12
LOOP6
I/O
PDO6
13
LOOP6
I/O
PADI6
14
LOOP7
I/O
PDO7
15
LOOP7
I/O
PADI7
16
Comments
PDOEN controls the LOOP0 through LOOP7 pins.
N/A
-
PDOEN
Setting PDOEN to “1” configures the pins as outputs. The output value to
the pin is set in PDO[0..7].
Setting PDOEN to “0” tristates all the pins. The input value to the pins can
be read in PADD[0.7].
17
TCLK1
I
TCLK1
18
TPOS1
I
TPOS1
19
TNEG1
I
TNEG1
20
RCLK1
O
RCLK1
21
RPOS1
O
RPOS1
22
RNEG1
O
RNEG1
N/A
-
HIZB1
24
LOS1
O
LOS1
25
TCLK0
I
TCLK0
26
TPOS0
I
TPOS0
27
TNEG0
I
TNEG0
23
Datasheet
HIZB1 controls the RPOS1, RNEG1 and RCLK1 pins. Setting HIZB1 to
“1” enables output on the pins. Setting HIZB1 to “0” tristates the pins.
21
LXT381 — Octal E1 Line Interface
Table 4.
Boundary Scan Register (BSR) (Continued)
Bit #
Pin
Signal
I/O
Type
Bit
Symbol
28
RCLK0
O
RCLK0
29
RPOS0
O
RPOS0
30
RNEG0
O
RNEG0
N/A
-
HIZB0
32
LOS0
O
LOS0
33
-
-
RESERVED1
34
LOS3
O
LOS3
35
RNEG3
O
RNEG3
36
RPOS3
O
RPOS3
N/A
-
HIZB3
38
RCLK3
O
RCLK3
39
TNEG3
I
TNEG3
40
TPOS3
I
TPOS3
41
TCLK3
I
TCLK3
42
LOS2
O
LOS2
43
RNEG2
O
RNEG2
44
RPOS2
O
RPOS2
N/A
-
HIZB2
46
RCLK2
O
RCLK2
47
TNEG2
I
TNEG2
48
TPOS2
I
TPOS2
49
TCLK2
I
TCLK2
50
-
-
RESERVED2
51
-
-
RESERVED3
52
-
-
RESERVED4
53
-
-
RESERVED5
54
-
-
RESERVED6
55
-
-
RESERVED7
56
-
-
RESERVED8
57
-
-
RESERVED9
58
TCLK5
I
TCLK5
59
TPOS5
I
TPOS5
60
TNEG5
I
TNEG5
61
RCLK5
O
RCLK5
62
RPOS5
O
RPOS5
31
37
45
22
Comments
HIZB0 controls the RPOS0, RNEG0 and RCLK0 pins. Setting HIZB0 to
“1” enables output on the pins. Setting HIZB0 to “0” tristates the pins.
HIZB3 controls the RPOS3, RNEG3 and RCLK3 pins. Setting HIZB3 to
“1” enables output on the pins. Setting HIZB3 to “0” tristates the pins.
HIZB2 controls the RPOS2, RNEG2 and RCLK2 pins. Setting HIZB2 to
“1” enables output on the pins. Setting HIZB2 to “0” tristates the pins.
Datasheet
Octal E1 Line Interface — LXT381
Table 4.
Boundary Scan Register (BSR) (Continued)
Bit #
Pin
Signal
I/O
Type
Bit
Symbol
63
RNEG5
O
RNEG5
N/A
-
HIZB5
65
LOS5
O
LOS5
66
TCLK4
I
TCLK4
67
TPOS4
I
TPOS4
68
TNEG4
I
TNEG4
69
RCLK4
O
RCLK4
70
RPOS4
O
RPOS4
71
RNEG4
O
RNEG4
N/A
-
HIZB4
LOS4
O
LOS4
64
72
73
74
OE
I
OE
75
RPOL
I
RPOL
76
LOS7
O
LOS7
77
RNEG7
O
RNEG7
78
RPOS7
O
RPOS7
N/A
-
HIZB7
80
RCLK7
O
RCLK7
81
TNEG7
I
TNEG7
82
TPOS7
I
TPOS7
83
TCLK7
I
TCLK7
84
LOS6
O
LOS6
85
RNEG6
O
RNEG6
86
RPOS6
O
RPOS6
N/A
-
HIZB6
88
RCLK6
O
RCLK6
89
TNEG6
I
TNEG6
90
TPOS6
I
TPOS6
91
TCLK6
I
TCLK6
92
-
-
RESERVED10
93
-
-
RESERVED11
94
-
-
RESERVED12
95
-
-
RESERVED13
79
87
Datasheet
Comments
HIZB5 controls the RPOS5, RNEG5 and RCLK5 pins. Setting HIZB5 to
“1” enables output on the pins. Setting HIZB5 to “0” tristates the pins.
HIZB4 controls the RPOS4, RNEG4 and RCLK4 pins. Setting HIZB4 to
“1” enables output on the pins. Setting HIZB4 to “0” tristates the pins.
HIZB7 controls the RPOS7, RNEG7 and RCLK7 pins. Setting HIZB7 to
“1” enables output on the pins. Setting HIZB7 to “0” tristates the pins.
HIZB6 controls the RPOS6, RNEG6 and RCLK6 pins. Setting HIZB6 to
“1” enables output on the pins. Setting HIZB6 to “0” tristates the pins.
23
LXT381 — Octal E1 Line Interface
Table 4.
Boundary Scan Register (BSR) (Continued)
Bit #
Pin
Signal
I/O
Type
Bit
Symbol
96
-
-
RESERVED14
97
-
-
RESERVED15
98
-
-
RESERVED16
3.3.2
Comments
Device Identification Register (IDR)
The IDR register provides access to the manufacturer number, part number and the LXT381
revision. The register is arranged per IEEE 1149.1 and is represented in Table 5. Data into the IDR
is shifted in LSB first
.
Table 5.
3.3.3
Device Identification Register (IDR)
Bit #
Comments
31 - 28
Revision Number
27 - 12
Part Number
11 - 1
Manufacturer Number
0
Set to ‘1’
Bypass Register (BYR)
The Bypass Register is a 1 bit register that allows direct connection between the TDI input and the
TDO output.
3.3.4
Analog Port Scan Register (ASR)
The ASR is a 5 bit shift register used to control the analog test port at pins AT1, AT2. When the
INTEST_ANALOG instruction is selected, TDI connects to the ASR input and TDO connects to
the ASR output. After 5 TCK rising edges, a 5 bit control code is loaded into the ASR. Data into
the ASR is shifted in LSB first.
Table 6 shows the 16 possible control codes and the corresponding operation on the analog port.
The Analog Test Port can be used to verify continuity across the coupling transformers primary
winding
.
Table 6.
24
Analog Port Scan Register (ASR)
ASR Control Code
AT1 Forces Voltage To:
AT2 Senses Voltage From:
11111
TTIP0
TRING0
11110
TTIP1
TRING1
11101
TTIP2
TRING2
11100
TTIP3
TRING3
11011
TTIP4
TRING4
11010
TTIP5
TRING5
Datasheet
Octal E1 Line Interface — LXT381
Table 6.
Analog Port Scan Register (ASR) (Continued)
ASR Control Code
AT1 Forces Voltage To:
AT2 Senses Voltage From:
11001
TTIP6
TRING6
11000
RTIP7
RRING7
10111
RTIP0
RRING0
10110
RTIP1
RRING1
10101
RTIP2
RRING2
10100
RTIP3
RRING3
10011
RTIP4
RRING4
10010
RTIP5
RRING5
10001
RTIP6
RRING6
10000
RTIP7
RRING7
The Analog Test Port can be used to verify continuity across the coupling transformer’s primary
winding. By applying a stimulus to the AT1 input, a known voltage will appear at AT2 for a given
load. This, in effect, tests the continuity of a receive or transmit interface. See Figure 8.
3.3.5
Instruction Register (IR)
The IR is a 3 bit shift register that loads the instruction to be performed. The instructions are shifted
LSB first. Table 7 shows the valid instruction codes and the corresponding instruction description.
Datasheet
25
LXT381 — Octal E1 Line Interface
Figure 8. Analog Test Port Application
JTAG Port
ASR Register
RTIP7
Transceiver 7
RRING7
TTIP7
TRING7
TTIP6
TRING6
1K
Analog Mux
RTIP6
RRING6
Transceiver 6
RTIP0
RRING0
Transceiver 0
1K
AT2
AT1
Table 7.
26
Instruction Register (IR)
Instruction
Code #
Comments
EXTEST
000
Connects the BSR to TDI and TDO. Input pins values are loaded into the BSR.
Output pins values are loaded from the BSR.
INTEST_ANALOG
010
Connects the ASR to TDI and TDO. Allows voltage forcing/sensing through AT1 and
AT2. Refer to Table 6.
SAMPLE / PRELOAD
100
Connects the BSR to TDI and TDO. The normal path between the LXT381 logic and
the I/O pins is maintained. The BSR is loaded with the signals in the I/O pins.
IDCODE
110
Connects the IDR to the TDO pin.
BYPASS
111
Serial data from the TDI input is passed to the TDO output through the 1 bit Bypass
Register.
Datasheet
Octal E1 Line Interface — LXT381
4.0
Test Specifications
Note:
Table 8.
Table 8 through Table 18 and Figure 9 through Figure 12 represent the performance specifications
of the LXT381 and are guaranteed by test except, where noted, by design. The minimum and
maximum values listed in Table 10 through Table 18 are guaranteed over the recommended
operating conditions specified in Table 9.
Absolute Maximum Ratings
Parameter
Symbol
Min
Max
Unit
DC supply voltage
Vcc0, Vcc1, Tvcc 07
-0.5
4.0
V
DC supply voltage
Vccio0, Vccio1,
-0.5
7.0
V
GND-0.5
VCCIO0 + 0.5
V
GND-0.5
VCCIO1 + 0.5
V
Input voltage on any digital pin
Vin
Input voltage on RTIP, RRING1
Vin
GND-0.5
VCC0 + 0.5
VCC1 + 0.5
V
ESD voltage on any Pin 2
Vin
2000
-
V
Transient latch-up current on any pin
Iin
-
100
mA
Input current on any digital pin 3
Iin
-10
10
mA
DC input current on TTIP, TRING 3
Iin
-
±100
mA
3
Iin
-
±100
mA
Tstor
-65
+150
°C
850
mW
Thermal resistance, junction to ambient,
144 pin LQFP package
28
°C/W
Thermal resistance, junction to ambient,
160 pin PBGA package
28
°C/W
DC input current on RTIP, RRING
Storage temperature
Maximum package power dissipation
PP
Caution: Exceeding these values may cause permanent damage.
Caution: Functional operation under these conditions is not implied.
Caution: Exposure to maximum rating conditions for extended periods may affect device reliability.
1. Referenced to ground.
2. Human body model.
3. Constant input current.
Table 9.
Recommended Operating Conditions
Parameter
Sym
Min.
Typ.
Max.
Unit
DC supply voltage
Vcc
3.135
3.3
3.465
V
Digital I/O DC supply voltage
Vcc
3.135
3.3
5.25
V
Ta
-40
25
+85
°C
Ambient operating temperature
Test Condition
3.3V ± 5%
1. Current consumption over the full operating temperature and power supply voltage range.
2. Digital inputs are within 10% of the supply rails and digital outputs are driving a 50pF load.
Datasheet
27
LXT381 — Octal E1 Line Interface
Table 9.
Recommended Operating Conditions (Continued)
Parameter
Average
transmitter
power supply
current 1
Sym
Min.
Typ.
Max.
Unit
75 Ω, coax cable
-
265
mA
100% 1’s density
120 Ω, TWP cable
-
210
mA
100% 1’s density
125
-
mA
50% 1’s density
100
-
mA
50% 1’s density
80
100
mA
18
25
mA
-
-
Ω
ITVCC
75 Ω, coax cable
-
120 Ω, TWP cable
Average core power supply current 1
IVCC
Average I/O power supply current 1, 2
IVCCIO
Output load at TTIP and TRING
-
Rl
40
Test Condition
1. Current consumption over the full operating temperature and power supply voltage range.
2. Digital inputs are within 10% of the supply rails and digital outputs are driving a 50pF load.
Table 10. DC Characteristics
Parameter
High level input voltage
Low level input voltage
High level output voltage
1
Min.
Typ.
Max.
Unit
VIH
2
-
-
V
VIL
-
-
0.8
V
VOH
2.4
VCCIO
V
IOUT= 400µA
IOUT= 1.6mA
VOL
-
-
0.4
V
Low level input voltage
VINL
–
–
1/3VCC-0.2
V
Midrange level input
voltage
VINM
1/3VCC+0.2
1/2VCC
2/3VCC-0.2
V
High level input voltage
VINH
2/3VCC+0.2
-
-
V
Low level input current
IINL
–
–
50
µA
High level input current
Low level output voltage
LOOP 0-7
1
Sym
IINH
–
–
50
µA
Input leakage current
IIL
-10
–
+10
µA
Tri state leakage current
IHZ
-10
–
+10
µA
Tri state output current
IHZ
-
-
1
µA
Line short circuit current
-
-
-
50
Input leakage:
TMS TDI TRST
-
-
-
50
Test Condition
The VCC
supply refers to
VCCIO0 or
VCCIO1 only.
TTIP, TRING
mA
RMS
2 x 11 Ω series
resistors and
1:2 transformer
µA
1. Output drivers will output CMOS logic levels into CMOS loads.
Table 11. Transmit Transmission Characteristics
Parameter
Sym
75 Ω
Output pulse
amplitude
120 Ω
Peak voltage of a
space
120 Ω
75 Ω
Transmit amplitude variation with supply
-
Min.
Typ.
Max.
Unit
2.14
2.37
2.60
V
2.7
3.0
3.3
V
0.237
V
0.3
V
+1
%
-0.237
-0.3
-1
-
Test Condition
Tested at the line side
1. Guaranteed by design and other correlation methods.
28
Datasheet
Octal E1 Line Interface — LXT381
Table 11. Transmit Transmission Characteristics (Continued)
Parameter
Sym
Min.
Typ.
Max.
Unit
Difference between pulse sequences
-
-
-
200
mV
For 17 consecutive
pulses
Pulse width ratio of the positive and negative pulses
-
0.95
-
1.05
-
At the nominal half
amplitude
Transmit transformer turns ratio for 75/120 Ω
characteristic impedance
-
-
1:2
-
-
15
17
15
18
15
17
15
18
15
19
15
18
-
0.030
51kHz to 102 kHz
Transmit return loss
75 Ω coaxial 1
Transmit return loss,
120 Ω twisted pair
cable 1
102 kHz to 2.048 MHz
-
2.048 MHz to 3.072 MHz
51kHz to 102 kHz
102 kHz to 2.048 MHz
-
2.048 MHz to 3.072 MHz
Transmit intrinsic jitter; 20Hz to 100kHz
-
Rt = 11 Ω ± 1%
dB
-
Using components in the
LXD381 evaluation
board
dB
dB
dB
-
Using components in the
LXD381 evaluation
board
dB
dB
0.050
Test Condition
U.I.
Tx path TCLK is jitter
free
1. Guaranteed by design and other correlation methods.
Table 12. Receive Transmission Characteristics
Parameter
Sym
Min.
Typ.
Max.
Unit
-
-
-
12
dB
Receiver dynamic range
DR
0.5
-
-
Vp
Signal to noise interference margin
S/I
-15
-
-
dB
Per G.703, O.151 @ 6 dB
cable attenuation
SRE
43
50
57
%
Rel. to peak input voltage
Data receiver squelch level
-
-
150
-
mV
Loss of signal threshold
-
-
200
-
mV
LOS hysteresis
-
-
50
-
mV
Receiver input impedance
-
-
70
-
kΩ
Input termination resistor tolerance
-
-
±1
%
Permissible cable attenuation
Data decision threshold
51 kHz - 102 kHz
Input return
loss1
102 - 2048 kHz
20
-
2048kHz - 3072 kHz
20
Test Condition
@1024 kHz
@ 1.024 MHz
dB
-
-
20
dB
Measured against nominal
impedance
dB
LOS delay time
-
-
30
-
µs
LOS reset
-
10
-
255
marks
1. Guaranteed by design and other correlation methods.
Datasheet
29
LXT381 — Octal E1 Line Interface
Table 13. Analog Test Port Characteristics
Parameter
3 dB Bandwidth
Sym
Min.
Typ.
Max.
Unit
at13db
-
5
-
MHz
V
V
Input voltage range
at1iv
0
-
VCC0
VCC1
Output voltage range
at2ov
0
-
VCC0
VCC1
Test Condition
Table 14. Transmit Timing Characteristics
Parameter
Output pulse width
Sym
Min.
Typ.
Max.
Unit
Test Condition
TW
219
244
269
ns
Transmit clock frequency
TCLK
-
2.048
-
MHz
Transmit clock tolerance
TCLKT
-50
-
+50
ppm
Transmit clock duty cycle
tDC
10
-
90
%
NRZ mode
TPOS/TNEG pulse width (RZ mode)
tMPW
236
-
252
ns
RZ mode (TCLK = H for
>16 clock cycles)
TPOS/TNEG to TCLK setup time
TSUT
20
-
-
ns
TCLK to TPOS/TNEG hold time
THT
20
-
-
ns
Delay time OE Low to driver Hi-Z
TOEZ
-
-
1
µS
Delay time TCLK Low to driver Hi-Z
TTZ
8
-
15
µS
Figure 9. Transmit Clock Timing
TCLK
tHT
tSUT
TPOS
TNEG
Table 15. Receive Timing Characteristics
Parameter
Sym
Min.
Typ.
Max.
Unit
Tr
20
-
-
ns
RPOS/RNEG pulse width
Tpwl
200
244
300
ns
Receiver throughput delay
Trxd
-
85
-
ns
-
-
-
5
ns
Rise/fall time 1
Delay time between RPOS/RNEG and RCLK
Test Condition
@ CL=15 pF
1. For all digital outputs.
30
Datasheet
Octal E1 Line Interface — LXT381
Figure 10. Receive Timing Diagram
RTIP
RRING
tRXD
tMPW
RPOS
tRXD
tPWL
RNEG
RPOL=L
Table 16. JTAG Timing Characteristics
Parameter
Sym
Min
Typ
Max
Unit
Cycle time
tCYC
200
-
-
ns
J-TMS/J-TDI to J-TCK rising edge time
tSUT
50
-
-
ns
tHT
50
-
-
ns
tDOD
-
-
50
ns
J-CLK rising to J-TMS/L-TDI hold time
J-TCLK falling to J-TDO valid
Test Conditions
Figure 11. JTAG Timing
tCYC
TCK
tSUR
tHT
TMS
TDI
tDOD
TDO
Datasheet
31
LXT381 — Octal E1 Line Interface
Table 17. Transformer Specifications
Leakage
Inductance
µH
(max.)
Interwinding
Capacitance
pF
(max.)
Tx/Rx
Turns Ratio
Primary
Inductance
mH
(min.)
TX
1:2
1.2
0.60
60
RX
1:1
1.2
0.60
60
DCR
Ω
(max.)
Dielectric Breakdown
Voltage V1
(min.)
0.70 pri
1500 Vrms
1.20 sec
1.10 pri
1500 Vrms
1.10 sec
1. This parameter is application dependent.
Table 18. G.703 2.048 Mbit/s Pulse Mask Specifications
Cable
Parameter
Unit
TWP
Coax
Test load impedance
120
75
Ω
Nominal peak mark voltage
3.0
2.37
V
Nominal peak space voltage
0 ±0.30
0 ±0.237
V
244
244
ns
Ratio of positive and negative pulse amplitudes at center of pulse
95-105
95-105
%
Ratio of positive and negative pulse amplitudes at nominal half amplitude
95-105
95-105
%
Nominal pulse width
32
Datasheet
Octal E1 Line Interface — LXT381
Figure 12. E1 Mask Templates
20%
20%
V = 100%
10% 10%
269 ns
(244+25)
194 ns
(244- 50)
NOMINAL PULSE
50%
244 ns
20%
10% 10%
0%
10% 10%
219 ns
(244-25)
488 ns
(244+244)
Datasheet
33
LXT381 — Octal E1 Line Interface
5.0
Mechanical Specifications
Figure 13. LXT381 144 Pin LQFP Package Dimensions
144-Pin Low-Profile Quad Flat Package
• Part Number LXT381LE
• Extended Temperature Range (-40 °C to 85
D
NOTE: All dimensions in millimeters.
D/2
b
e
E/2
E1/2
e/2
E1
E
M
0 DEG. MIN.
A2
0.08 / 0.20 R.
D1/2
A1
D1
0.08 R. MIN.
A
0.25
L
1.00
REF.
0 - 7 DEG.
Millimeters
Dimension1
Minimum
Nominal
Maximum
A
-
-
1.60
A1
0.05
0.10
0.15
A2
1.35
1.40
1.45
b
0.17
0.22
0.27
D
22.00 B.S.C.
D1
20.00 B.S.C.
E
22.00 B.S.C.
E1
20.00 B.S.C.
e
0.50 B.S.C.
L
0.45
0.60
0.75
M
0.14
-
-
1. See JEDEC Publication for additional specifications.
34
Datasheet
Octal E1 Line Interface — LXT381
Figure 14. LXT381 160 Pin PBGA Package Dimensions
160-Pin Plastic Ball Grid Array
• Part Number LXT381BE
• Extended Temperature Range (-40 °C to 85 °C)
15.00
1.00 REF
13.00 ±0.20
PIN #A1
CORNER
4.72 ±0.10
13.00
1.00
A
0.50 B
±0.10 C
PIN #A1 ID
D
4.72 ±0.10
1.00
E
F
13.00
15.00
±0.20
G
13.0
H
J
K
L
M
N
P
Ø1.00
(3 plcs)
14 13 12 11 10 9
TOP VIEW
8
7 6
5 4
3
2 1
1.00 R
BOTTOM VIEW
0.85
1.61
± 0.19
NOTE:
1. ALL DIMENSIONS IN MILLIMETERS.
SEATING PLANE
SIDE VIEW
Datasheet
0.36
±0.04
0.40
± 0.10
2. ALL DIMENSIONS AND TOLERANCES
CONFORM TO ASME Y 14.5M-1994.
3. TOLERANCE = ± 0.05 UNLESS
SPECIFIED OTHERWISE.
35