ETC LXT336QE

LXT336
Quad T1/E1 Receiver
Datasheet
The LXT336 quad receiver is a fully-integrated, quadruple-PCM receiver for both T1 (1.544
Mbps) and E1 (2.048 Mbps) applications. It incorporates four independent receivers in a single
64-pin QFP package.
The LXT336 features a differential receiver architecture with high noise interference margin. It
uses peak detection with a variable threshold for reliable recovery of data as low as 500 mV and
up to 12 dB of cable attenuation.
The fully digital clock recovery system uses a low frequency master clock of 2.048 MHz or
1.544 MHz as its reference. In addition, each LXT336 receiver incorporates a Loss of Signal
(LOS) detection circuit. The LOS detector is compliant with both ITU-T G.775 and ANSI
T1.231 standards.
The LXT336 ports can be independently configured for either unipolar or bipolar output modes.
HDB3 and AMI decoding mechanisms are available in unipolar mode.
Applications
■
■
Test Equipment
DSX-1 and E1 Line Monitoring
■
High density T1/E1 line cards
■
Low frequency 1.544 or 2.048 MHz
reference clock
Programmable unipolar and bipolar PCM
interface
On-chip AMI and HDB3 decoders
Loss of Signal processors conform to ITU
G.775 and ANSI T1.231 recommendations
Small-footprint 64-pin QFP
Optional RZ Data recovery mode
Product Features
■
■
■
■
■
Fully integrated quad, receiver for E1 2.048
Mbps or T1 1.544 Mbps operation
Single rail supply voltage of 5 V (typical)
Low power consumption: 250 mW for E1;
200 mW for T1 (typical)
High-performance receivers recover data
with up to 12 dB cable attenuation
On-chip clock recovery function complies
with ITU G.823 and Bellcore GR-499CORE
■
■
■
■
■
As of January 15, 2001, this document replaces the Level One document
LXT336 — Quad T1/E1 Receiver.
Order Number: 249046-001
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 LXT336 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
Quad T1/E1 Receiver — LXT336
Contents
1.0
Pin Assignments & Signal Descriptions\ ......................................................... 6
2.0
Functional Description...........................................................................................10
2.1
3.0
Receiver Description ...........................................................................................10
2.1.1 Loss Of Signal Detector .........................................................................10
2.1.1.1 E1 LOS Detection......................................................................10
2.1.1.2 T1 LOS Detection......................................................................11
2.1.1.3 Data Recovery Mode LOS Detection ........................................11
2.1.1.4 In-Service Code Violation Monitoring ........................................11
Application Information .........................................................................................12
3.1
Monitoring Applications .......................................................................................12
3.1.1 Receive Line Interface Applications .......................................................13
4.0
Test Specifications ..................................................................................................16
5.0
Mechanical Specifications....................................................................................22
Figures
1
2
3
4
5
6
7
8
LXT336 Block Diagram ......................................................................................... 5
LXT336 Pin Assignments and Package Markings ................................................ 6
Typical Monitoring Application.............................................................................13
Typical Receive Line Interface Application..........................................................14
LXT336 Receive Timing Diagram .......................................................................19
E1 Jitter Tolerance—G.823.................................................................................20
T1 Jitter Tolerance—GR-499-CORE Category II ................................................21
Package Specifications .......................................................................................22
1
2
3
4
5
6
7
8
9
LXT336 Pin Descriptions....................................................................................... 7
Transformer Specifications..................................................................................15
Absolute Maximum Ratings.................................................................................16
Recommended Operating Conditions .................................................................16
DC Characteristics (Over Recommended Range) ..............................................16
E1 Receive Characteristics (Over Recommended Range) .................................17
T1 Receive Characteristics (Over Recommended Range) .................................18
Timing Characteristics (Over Recommended Range).........................................19
Relevant Recommendations ...............................................................................21
Tables
Datasheet
3
LXT336 — Quad T1/E1 Receiver
Revision History
Revision
4
Date
Description
Datasheet
Quad T1/E1 Receiver — LXT336
Figure 1. LXT336 Block Diagram
MODE
UBS
LOS
Detector
LOS
RPOS/
RDATA
RNEG/
BPV
RCLK
MCLK
AMI / HDB3
Unipolar
Decoder
Data
Recovery
Data
Slicers
Peak
Dectector
RTIP
RRING
Clock
Recovery
Port 0
Port 1
Port 2
Port 3
Datasheet
5
LXT336 — Quad T1/E1 Receiver
1.0
Pin Assignments & Signal Descriptions\
LXT336QE XX
XXXXXX
XXXXXXXX
Rev #
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
7
8
9 Part #
10 LOT #
11 FPO #
12
13
14
15
16
NC
CLKI3
GND
UBS3
CLKI2
GND
UBS2
VCC
NC
GND
VCC
NC
NC
GND
VCC
NC
GND
MODE
RRING0
RTIP0
LOS0
RRING1
RTIP1
LOS1
RRING2
RTIP2
LOS2
RRING3
RTIP3
LOS3
GND
CLKE
MCLK
CLKI0
GND
UBS0
CLKI1
GND
UBS1
GND
NC
GND
VCC
NC
NC
GND
VCC
NC
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
RCLK0
RPOS0 / RDATA0
RNEG0 /BPV0
RCLK1
RPOS1 / RDATA1
RNEG1 / BPV1
NC
NC
NC
NC
RCLK2
RPOS2 / RDATA2
RNEG2 / BPV2
RCLK3
RPOS3 / RDATA3
RNEG3 / BPV3
Figure 2. LXT336 Pin Assignments and Package Markings
Package Topside Markings
Marking
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 #
6
Definition
Identifies the Finish Process Order.
Datasheet
Quad T1/E1 Receiver — LXT336
Table 1.
Pin
#
LXT336 Pin Descriptions
Sym
I/O1
Description
1
MCLK
DI
Master Clock Input. An independent and free-running 2.048 or 1.544 MHz clock input
generates the internal reference clocks for all Receivers. On Loss of Signal (LOS), the
LXT336 derives RCLKx from this master clock. With MCLK asserted High, the LXT336
disables the PLL clock recovery circuits. The Receiver then feeds RPOSx and RNEGx to
an internal XOR gate that performs logically exclusive ORs for both data signals and
connects this output to RCLKx for external clock recovery. In this mode, the LXT336
operates as a data recovery circuit. With MCLK asserted Low, the LXT336 powers down
its clock and data recovery circuits and switches the output pins RCLKx, RPOSx and
RNEGx to tri-state mode.
MCLK Operating Mode
Clocked Data/Clock Recovery
L
Power Down
H
Data Recovery
2
CLKI0
DI
Clock Input - Port 0. All CLKIx pins are identical. Connect to MCLK for unipolar operation
mode (single rail plus clock). For bipolar operation mode (dual rail plus clock), CLK0
should be connected to ground.
3
GND
S
Ground.
Unipolar-Bipolar Select Input–Port 0. All UBSx pins are identical. If this pin is asserted
High for more than 16 CLKI cycles, the LXT336 switches to unipolar mode. HDB3 or AMI
decoder mode is selected by the MODE pin.
4
UBS0
DI
The device is set to bipolar mode when this pin is asserted Low.
UBSx Operating Mode
L
Bipolar Mode
H
Unipolar Mode
5
CLKI1
DI
Clock Input - Port 1. See CLKI0, pin 2.
6
GND
S
Ground.
7
UBS1
DI
Unipolar-Bipolar Select Input–Port 1. See UBS0, pin 4.
8
GND
S
Ground.
9
NC
-
Not Connected. Must be left open.
10
GND
S
Ground.
11
VCC
S
Positive Supply. +5 VDC power supply.
12
NC
-
Not Connected. Must be left open.
13
NC
-
Not Connected. Must be left open.
14
GND
S
Ground.
15
VCC
S
Positive Supply. +5 VDC power supply.
16
NC
-
Not Connected. Must be left open.
17
GND
S
Ground.
1. Entries in I/O column are: DI = digital input; DO = digital output; DI/O = digital input/output; AI = analog input; AO = analog
output; S = supply. Note: Do not leave digital inputs floating, with the exception of not connected (NC) pins.
Datasheet
7
LXT336 — Quad T1/E1 Receiver
Table 1.
Pin
#
18
LXT336 Pin Descriptions (Continued)
Sym
MODE
I/O1
DI
Description
Mode Select Input. In unipolar mode, if this pin is pulled Low, all transceivers operate in
E1 mode using AMI decoding. With this pin pulled High, all transceivers enter E1 mode
using HDB3 decoding. With this pin set to 2.5V, the LXT336 enters T1 mode with AMI
decoding.
MODE Operating Mode
L
E1 Mode with AMI Decoding
H
E1 Mode with HDB3 Decoding
2.5V
T1 Mode with AMI Decoding
The 2.5V reference is obtained with a resistive divider consisting of two 10 KΩ resistors
across VCC and GND.
19
RRING0
AI
20
RTIP0
AI
21
LOS0
DO
22
RRING1
AI
23
RTIP1
AI
Receive Ring Input–Port 1/Receive TIP Input–Port 1. See RRING0, pin 19; RTIP0, pin
20.
24
LOS1
DO
Loss of Signal Output–Port 1. See LOS0, pin 21.
25
RRING2
AI
26
RTIP2
AI
Receive Ring Input–Port 2/Receive TIP Input–Port 2. See RRING0, pin 19; RTIP0, pin
20.
27
LOS2
DO
Loss of Signal Output–Port 2. See LOS0, pin 21.
28
RRING3
AI
29
RTIP3
AI
Receive Ring Input–Port 3/Receive TIP Input–Port 3. See RRING0, pin 19; RTIP0, pin
20.
30
LOS3
DO
Loss of Signal Output–Port 3. See LOS0, pin 21.
31
GND
S
Ground.
32
CLKE
DI
Clock Edge Select Input.
CLKE Result
L
RPOS, RNEG valid on falling edge of RCLK
H
RPOS, RNEG valid on rising edge of RCLK
33
NC
-
Not Connected. Must be left open.
34
VCC
S
Positive Supply. +5 VDC power supply.
35
GND
S
Ground.
36
NC
-
Not Connected. Must be left open.
37
NC
-
Not Connected. Must be left open.
38
VCC
S
Positive Supply. +5 VDC power supply.
39
GND
S
Ground.
Receive Ring Input–Port 0/Receive TIP Input–Port 0. These pins are the inputs of the
fully differential line receiver.
Loss of Signal Output–Port 0. All LOSx pins are identical. This output is High when a
valid loss of signal condition is detected. See page 10 for more information. In data
recovery mode, LOSx is a pure analog energy detector.
40
NC
-
Not Connected. Must be left open.
41
VCC
S
Positive Supply. +5 VDC power supply
42
UBS2
DI
Unipolar-Bipolar Select Input–Port 2. See UBS0, pin 4.
43
GND
S
Ground.
44
CLKI2
DI
Clock Input - Port 2. See CLKI0, pin 2.
45
UBS3
DI
Unipolar-Bipolar Select Input–Port 3. See UBS0, pin 4.
1. Entries in I/O column are: DI = digital input; DO = digital output; DI/O = digital input/output; AI = analog input; AO = analog
output; S = supply. Note: Do not leave digital inputs floating, with the exception of not connected (NC) pins.
8
Datasheet
Quad T1/E1 Receiver — LXT336
Table 1.
LXT336 Pin Descriptions (Continued)
Pin
#
Sym
I/O1
46
GND
S
Ground.
47
CLKI3
DI
Clock Input - Port 3. See CLKI0, pin 2.
48
NC
-
49
RNEG3/ BPV3
DO
Description
Not Connected. Must be left open.
Receive Negative Data/Bipolar Violation Indication Output–Port 3. All RNEGx/BPVx
pins are identical. In bipolar mode these pins act as active High bipolar non-return-to-zero
(NRZ) receive signal outputs. A High signal on RNEGx corresponds to receipt of a
negative pulse on RTIPx/RRINGx. A High signal on RPOSx corresponds to receipt of a
positive pulse on RTIPx/RRINGx. Both signals are valid on the same edge of RCLKx, as
determined by the CLKE pin.
In unipolar mode, the LXT336 asserts the BPVx pin High any time it senses an In-Service
Line Code violation.
In data recovery mode, this pin is an active Low RZ output. See RPOS3/RDATA3, pin 50;
and Functional Description.
Receive Positive Data/Receive Data Output–Port 3. A High signal on RPOSx
corresponds to receipt of a positive pulse on RTIPx/RRINGx.
RPOS3/
RDATA3
50
DO
In unipolar mode, the LXT336 asserts RDATAx High when a mark has been received. This
signal is valid on the edge of RCLKx as determined by the CLKE pin. RDATAx is an NRZ
receive data output.
In Data Recovery mode, this pin is an active Low RZ output. See RNEG3/BPV3, pin 49.
51
RCLK3
DO
52
RNEG2/BPV2
DO
53
RPOS2/
RDATA2
DO
RCLK2
DO
54
Receive Clock Output–Port 3. All RCLKx pins are identical. This pin provides the
recovered clock from the signal received at RTIPx and RRINGx. In loss of signal
conditions the LXT336 connects MCLK to this pin through internal circuitry.
Asserting the MCLK pin High disables the clock recovery circuit and internally connects
RPOSx and RNEGx to an XOR that is fed to the RCLKx output for external clock recovery
applications.
Receive Negative Data/Violation Indication Output–Port 2. See RNEG3/BPV3, pin 49;
RPOS3/RDATA3, pin 50.
Receive Positive Data/Receive Data Output–Port 2. See RPOS3/RDATA3, pin 50;
RNEG3/BPV3, pin 49.
In Data Recovery Mode, this signal is active Low.
Receive Clock Output–Port 2. See RCLK3, pin 51.
55
NC
-
Not connected. Must be left open.
56
NC
-
Not connected. Must be left open.
57
NC
-
Not connected. Must be left open.
58
NC
-
Not connected. Must be left open.
59
RNEG1/BPV1
DO
Receive Negative Data/Bipolar Violation Indication Output–Port 1. See RNEG3/
BPV3, pin 49; RPOS3/RDATA3, pin 50.
60
RPOS1/
RDATA1
DO
Receive Positive Data/Receive Data Output–Port 1. See RPOS3/RDATA3, pin 50;
RNEG3/BPV3, pin 49.
61
RCLK1
DO
Receive Clock Output–Port 1. See RCLK3, pin 51.
62
RNEG0/BPV0
DO
Receive Negative Data/Bipolar Violation Indication Output–Port 0. See RNEG3/
BPV3, pin 49; RPOS3/RDATA3, pin 50.
63
RPOS0/
RDATA0
DO
Receive Positive Data/Receive Data Output–Port 0. See RPOS3/RDATA3, pin 50;
RNEG3/BPV3, pin 49.
64
RCLK0
DO
Receive Clock Output–Port 0. See RCLK3, pin 51.
1. Entries in I/O column are: DI = digital input; DO = digital output; DI/O = digital input/output; AI = analog input; AO = analog
output; S = supply. Note: Do not leave digital inputs floating, with the exception of not connected (NC) pins.
Datasheet
9
LXT336 — Quad T1/E1 Receiver
2.0
Functional Description
The LXT336 quad receiver is a fully-integrated, PCM receiver for both 1.544 Mbps (DSX-1) and
2.048 Mbps (E1) applications. The MCLK frequency and the MODE pin input level set the mode
of operation. The LXT336 is a low-power CMOS device operating from a single +5 V power
supply. Refer to the LXT336 block diagram on page 1.
Each receiver interfaces with back-end processors through bipolar or unipolar data I/O channels
and allows control by hardwired pins for stand-alone operation.
2.1
Receiver Description
The four receivers in the LXT336 are identical. The following paragraphs describe the operation of
a single receiver.
The LXT336 receives the input signal at RTIP/RRING via a 1:1 or 1:2 coupling transformer. Data
slicers and a peak detector process the received signal. The peak detector samples the received
signal and determines its maximum value. A data-rate dependent percentage of peak value goes to
the data slicers as a threshold level to ensure an optimum signal-to-noise ratio.
The receiver accurately recovers signals with up to -12 dB of cable loss. The minimum receiver
sensitivity signal level is approximately 500 mV peak to peak. Regardless of the received signal
level, the LXT336 holds its peak detectors above a minimum level (0.225 V) to provide immunity
from impulse noise.
After the data slicers process the received signal, it is fed to the data and timing recovery section,
and to the receive monitor. The data and timing recovery circuits provide an input jitter tolerance
significantly better than required by ITU-T G.823 and GR-499-CORE Category II. Refer to the
Test Specifications section for details.
The recovered clock is output at RCLK in both bipolar and unipolar modes.
In bipolar mode, recovered data is active High and output at RPOS and RNEG; in unipolar mode
recovered data is active High and output at RDATA.
If CLKE is Low, RPOS and RNEG outputs are valid on the falling edge of RCLK. If CLKE is
High, RPOS and RNEG outputs are valid on the rising edge of RCLK.
Asserting MCLK High disables the clock recovery function and switches all receivers to data
recovery mode. In data recovery mode, the RPOS/RNEG outputs are active Low, return-to-zero
(RZ) outputs. Asserting MCLK Low powers all receivers down and holds RPOS/RNEG and
RCLK in a high impedance state.
2.1.1
Loss Of Signal Detector
2.1.1.1
E1 LOS Detection
During E1 operation, the ITU G.775 detection criterion is employed. The Loss of Signal (LOS)
detector uses a combination analog and digital detection scheme and complies with the ITU G.775
recommendation.
10
Datasheet
Quad T1/E1 Receiver — LXT336
The receiver monitor loads a digital counter at the RCLK frequency. The monitor increments the
counter with each received 0 (space), and resets it to 0 with each received 1 (mark). Any signal 21
dB below the nominal 0 dB signal for 32 consecutive pulse intervals generates a LOS condition.
The LXT336 sets the LOS flag, and replaces the recovered clock with MCLK at the RCLK output
in a smooth transition. (Normal operation requires MCLK.) LOS is cleared again when the signal
level rises above 21 dB (typical) below the minimum 0 dB level and the average 1s density reaches
12.5% (i.e. four marks in a 32-bit window). Another smooth transition replaces MCLK with the
recovered clock at RCLK. During LOS conditions, received data is output on RPOS/RNEG (or
RDATA in unipolar I/O mode).
2.1.1.2
T1 LOS Detection
During T1 operation, the ANSI T1.231 detection criterion is employed. The LXT336 asserts LOS
if it receives 175 consecutive zeros, and de-asserts LOS when the signal reaches 12.5% ones
density (i.e. 16 marks in a 128-bit window with no more than 99 consecutive zeros).
2.1.1.3
Data Recovery Mode LOS Detection
In data recovery mode, the LOS detector uses an analog detection scheme compliant with ITU-T
G.775. Any signal 22 dB (typical) below the nominal 0 dB signal for more than approximately 16
µs generates a LOS condition. LOS is cleared when the signal level of the first 1 rises to more than
21 dB (typical) below the minimum 0 dB level. During LOS conditions, received data is output on
RPOS/RNEG.
2.1.1.4
In-Service Code Violation Monitoring
In unipolar AMI I/O Mode, the LXT336 reports bipolar violations using an active High output for
one RCLK cycle on the BPV output. A bipolar violation, in AMI encoding mode, is two
consecutive marks of the same polarity. With the HDB3 detector enabled (MODE pulled High),
the decoder will detect AMI code violations that are not part of a zero substitution code.
HDB3 code violations omit sequences of zeros that violate the coding rules. If an HDB3 code
violation occurs, the decoder asserts the BPV output for one RCLK cycle during the period of the
violating bit. In the event the decoder receives a sequence of four or more zeros, it asserts the BPV
output during the entire sequence of violating data bits.
Datasheet
11
LXT336 — Quad T1/E1 Receiver
3.0
Application Information
The LXT336 is well suited for both line interface equipment and monitoring applications. The
following paragraphs describe the recommended configuration for these applications.
3.1
Monitoring Applications
Figure 3 shows a typical configuration for monitoring applications. The 432Ω resistors are usually
included in the monitoring jack for DSX-1 applications. These resitors provide approximately
20dB of resistive attenuation when terminated into an 100Ω impedance. The 1:2 step up
transformer in the receive interface is used to boost-up the signal as seen by the LXT336. The two
resistors (Rx) determine the receive termination impedance and are selected according to the
nominal cable impedance as specified in the table at the bottom of Figure 3. The series 1k Ω
resistors provide protection against surges coupled to the device. Due to the high input impedance
of the LXT336, typically 40k Ω, these series resistors do not affect receiver sensitivity.
12
Datasheet
Quad T1/E1 Receiver — LXT336
Figure 3. Typical Monitoring Application
TP
TP
CROSS-CONNECT
Reference Point
TP
TP
TP
TP
TP
432
W
432
W
432
W
TP
432
W
LXT 336
1:2
Rx
1k Ω
Rx
0.22µF
RTIP1
RPOS1
RCLK1
RRING1
RNEG1
RTIP2
RPOS2
1k Ω
1:2
Rx
1k Ω
RCLK2
Rx
0.22µF
RRING2
RNEG2
RTIP3
RPOS3
1k Ω
1:2
Rx
Rx
1k Ω
RCLK3
0.22µF
RRING3
RNEG3
RTIP4
RPOS4
1k Ω
1:2
Rx
Rx
1k Ω
RCLK4
0.22µF
RRING4
RNEG4
1k Ω
+5V
es
VCC
33 µF
Cable Impedance
E1, 120 Ω
3.1.1
GND
0.1 µF
T1, 100 Ω
Receive Line Interface Applications
Figure 4 shows the typical LXT336 configuration for receive line interface applications. A 1:1
transformer is used in combination with the appropriate termination resistors Rx. These resistors
must be selected to match the line impedance as specified in the table at the bottom of Figure 4.
Datasheet
13
LXT336 — Quad T1/E1 Receiver
Figure 4. Typical Receive Line Interface Application
1K Ω
1:1
LXT 336
RTIP0
RPOS0
Rx
RCLK0
0.22uF
Rx
1K Ω
1:1
RRING0
RNEG0
RTIP1
RPOS1
Rx
RCLK1
0.22uF
Rx
1K Ω
1:1
RRING1
RTIP2
RNEG1
RPOS2
Rx
0.22uF
RCLK2
Rx
RRING2
RNEG2
1K Ω
1:1
RTIP3
RPOS3
Rx
0.22uF
RCLK3
Rx
RRING3
1K Ω
RNEG3
MCLK
+5V
VCC
1.544/2.048 MHz
GND
0.1 µF
33 µF
Rx Values
Cable Impedance
E1
75 Ω
E1
120 Ω
T1
100 Ω
37.5 Ω
60 Ω
50 Ω
Resistor values are ± 1%
14
Datasheet
Quad T1/E1 Receiver — LXT336
Table 2.
Transformer Specifications
Turns Ratio
Primary
Inductance
mH
(min.)
Leakage
Inductance
µH
(max.)
Interwinding
Capacitance
pF
(max.)
1:2 or 1:1
1.2
0.60
30
DCR
Ω
(max.)
1.00 pri
1.20 sec
Dielectric
Breakdown Voltage
V1
(min.)
1500 Vrms
1. This parameter is application dependent.
Datasheet
15
LXT336 — Quad T1/E1 Receiver
4.0
Test Specifications
Note:
Table 3.
The minimum and maximum values in Table 3 through Table 9 and Figure 5 through Figure 7
represent the performance specifications of the LXT336 and are guaranteed by test except, where
noted, by design or other correlation methods.
Absolute Maximum Ratings
Parameter
Sym
DC supply voltage
Unit
-0.3
6.0
V
VIN
GND -0.3
RVCC + 0.3
V
VIN
-6
RVCC + 0.3
V
IIN
–
100
mA
IIN
-10
10
mA
IIN
–
±20
mA
TSTOR
-65
+150
°C
–
–
1
W
Input voltage on RTIP/RRING
Input current on any digital pin
Max
RVCC, RGND
Input voltage on any pin1
Transient latchup current on any pin
Min
2
3
DC input current on RTIP, RRING3
Storage temperature
Total package power dissipation
Caution: Exceeding these values may cause permanent damage to the device. Operation is not guaranteed under these
conditions. Exposure to absolute maximum rating conditions for extended periods may adversely affect device
reliability.
1. Referenced to ground.
2. Exceeding these values will cause SCR latch-up.
3. Constant input current.
Table 4.
Recommended Operating Conditions
Parameter
Sym
Min
Typ
Max
Unit
DC supply voltage
V+
4.75
5.0
5.25
V
Ambient operating temperature
TA
-40
25
+85
°C
Table 5.
DC Characteristics (Over Recommended Range)
Parameter
Typ1
Sym
Min
High level input voltage
VIH
2.0
–
–
V
Low level input voltage
VIL
—
–
0.8
V
VOH
3.5
–
–
V
IOUT= -400µA
VOL
—
–
0.4
V
IOUT= 1.6 mA
Input leakage current (digital input pins)
IIL
-10
–
+10
µA
Tristate leakage current
IHZ
-10
+10
µA
Digital I/O pins
High level output voltage2
Low level output voltage
2
Max
Unit
Test Condition
pins 49 - 54, 59 - 64
1. Typical figures are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Output Drivers will output CMOS logic levels into CMOS loads.
3. Digital outputs driving a 50 pF load; all channels receiving line signal.
16
Datasheet
Quad T1/E1 Receiver — LXT336
Table 5.
DC Characteristics (Over Recommended Range) (Continued)
Parameter
MODE input pin
Total power
dissipation3
Sym
Min
Typ1
Max
Unit
Low level input voltage
VINL
–
–
1.5
V
High level input voltage
VINH
3.5
–
–
V
Midrange input voltage
VINM
2.3
2.5
2.7
V
Low level input current
IINL
–
–
50
µA
pin 18
High level input current
IINH
–
–
50
µA
E1 operation
PD
–
250
340
mW
T1 operation
PD
–
200
290
mW
ICCO
–
–
10
mA
Power down current
Test Condition
1. Typical figures are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Output Drivers will output CMOS logic levels into CMOS loads.
3. Digital outputs driving a 50 pF load; all channels receiving line signal.
Table 6.
E1 Receive Characteristics (Over Recommended Range)
Parameter
Sym
Permissible cable attenuation2
Min
Typ1
Max
Unit
Test Condition
–
–
–
12
dB
Receiver dynamic range
DR
0.5
–
4.2
Vp
Signal to noise interference margin 2, 6
S/I
-15
–
–
dB
Per G.703, O.151, 6 dB
of cable.
Signal to single tone interference margin2
S/X
-14
–
–
dB
O.151, 6 dB of cable
Data decision threshold
SRE
43
50
57
%
Relative to peak input
voltage.
–
–
2255
–
mV
dB
Analog loss of signal threshold
Loss of signal threshold hysteresis
–
–
2.5
–
Consecutive zeros before loss of signal
–
–
32
–
6
G.775 recommendation
1.2E-5 Hz to 20 Hz
–
36
–
–
U.I.
Low limit input jitter
tolerance 3
20 Hz to 2.4 kHz
–
1.5
–
–
U.I.
8 kHz to 100 kHz
–
0.2
–
–
U.I.
RCLK output jitter4, 6
0 Hz to100 kHz
–
–
0.01
–
U.I.
Clock recovery PLL 3 dB bandwidth
–
–
10
–
kHz
7
–
–
–
0
dB
Receiver input impedance
–
–
40
–
kΩ
PLL peaking
@1024 kHz
G.823 recommendation
peak to peak
@1024 kHz RTIP to
RRING
1. Typical figures are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Line interface application. No errors shall occur when the combined signal attenuated by the maximum specified
interconnecting cable loss is applied to the input port. See ITU O.151 recommendation for further details.
3. Sine wave jitter and wander with a peak to peak amplitude that corresponds at least to what is specified in Figure 6 shall not
cause either a bit error or loss of frame alignment. As test signal an HDB3-coded digital signal with an electrical characteristic
that complies with what is set forth in ITU G.703 shall be used. Test sequence is pseudo-random 215-1. See also ITU O.151.
4. If the LXT336 is configured as data receiver only and if a jitter free signal is applied to RTIP and RRING the added jitter must
not exceed the specified value.
5. Equal to 22 dB below the nominal 0 dB level in 120 Ω systems.
6. Guaranteed by design and other correlation methods.
7. Guaranteed by design and other correlation methods. There will be no jitter gain within the specified operating range.
Datasheet
17
LXT336 — Quad T1/E1 Receiver
Table 6.
E1 Receive Characteristics (Over Recommended Range) (Continued)
Parameter
Receiver return loss6
Sym
Min
Typ1
Max
Unit
51 kHz–102 kHz
–
20
–
–
dB
102–2048 kHz
–
20
–
–
dB
2048 kHz–3072
kHz
–
20
–
–
dB
Test Condition
See Application
Information section.
1. Typical figures are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Line interface application. No errors shall occur when the combined signal attenuated by the maximum specified
interconnecting cable loss is applied to the input port. See ITU O.151 recommendation for further details.
3. Sine wave jitter and wander with a peak to peak amplitude that corresponds at least to what is specified in Figure 6 shall not
cause either a bit error or loss of frame alignment. As test signal an HDB3-coded digital signal with an electrical characteristic
that complies with what is set forth in ITU G.703 shall be used. Test sequence is pseudo-random 215-1. See also ITU O.151.
4. If the LXT336 is configured as data receiver only and if a jitter free signal is applied to RTIP and RRING the added jitter must
not exceed the specified value.
5. Equal to 22 dB below the nominal 0 dB level in 120 Ω systems.
6. Guaranteed by design and other correlation methods.
7. Guaranteed by design and other correlation methods. There will be no jitter gain within the specified operating range.
Table 7.
T1 Receive Characteristics (Over Recommended Range)
Sym
Min
Typ1
Max
Unit
–
–
–
12
dB
Receiver dynamic range
DR
0.5
–
4.2
Vp
Undershoot
US
–
–
62
%
Data decision threshold
SRT
63
70
77
%
Loss of signal threshold
–
–
0.225
–
V
–
–
175
–
–
10
–
–
Parameter
Permissible cable attenuation
Allowable consecutive 0s before LOS
Low limit input jitter
tolerance 3
2
10 Hz to 192.9 Hz
6.43KHz to 40KHz
Clock recovery PLL 3 dB bandwidth
0.3
U.I.
U.I.
–
–
10
–
kHz
–
–
–
0
dB
Receiver input impedance
–
–
40
–
kΩ
Input return loss2
@772 kHz, Line interface
application
Relative to peak input voltage.
T1.231
4
PLL peaking
Test Condition
51 kHz–102 kHz
–
20
–
–
dB
102–2048 kHz
–
20
–
–
dB
2048 kHz–3072 kHz
–
20
–
–
dB
GR-499-CORE Category II
equipment
RTIP to RRING @ 772 kHz
See Application Information
section.
1. Typical figures are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. Guaranteed by design and other correlation methods.
3. Sinewave jitter with a peak-to-peak amplitude that corresponds, at minimum, with Figure 7, shall not cause bit errors or loss
of frame alignment.
4. Guaranteed by design and other correlation methods. There will be no jitter gain within the specified operating range.
18
Datasheet
Quad T1/E1 Receiver — LXT336
Table 8.
Timing Characteristics (Over Recommended Range)
Parameter
E1
Sym
Min
Typ1
Max
Unit
MCLK
–
2.048
–
MHz
Test
Condition
Master clock frequency
T1
Master clock tolerance
Master clock duty cycle
Receive clock capture range
Receive clock duty cycle
5
2
Receive clock pulse width 2
Receive clock pulse
width low time
Receive clock pulse
width high time
RPOS/RNEG data low time (MCLK=High)
MCLK
–
1.544
–
MHz
MCLKt
–
±50
–
ppm
–
40
60
%
–
–
–
ppm
±80
RLCKd
40
50
60
%
E1
tPW
447
488
529
ns
T1
tPW
594
648
702
ns
E1
tPWL
203
244
285
ns
T1
tPWL
270
324
378
ns
E1
tPWH
–
244
–
ns
T1
tPWH
–
324
–
ns
tPWD1
200
244
300
ns
3, 4
RPOS/RNEG to RCLK
E1
tSUR
50
203
–
ns
rising setup time
T1
tSUR
50
270
–
ns
RCLK rising to RPOS/RNEG
E1
tHR
50
203
–
ns
hold time
T1
tHR
50
270
–
ns
–
–
5
–
ns
Delay time between RPOS/RNEG and RCLK
From nominal
MCLK = High
1. Typical figures are at 25 °C and are for design aid only; not guaranteed and not subject to production testing.
2. RCLK duty cycle will vary depending on extent of received pulse jitter displacement. Maximum and minimum RCLK duty
cycles are for worst case jitter conditions (0.2 U.I. displacement for E1 and 0.4 U.I. for T1 operation).
3. This mode disables clock recovery.
4. If MCLK is High, the PLL clock recovery circuits are disabled. RPOSx and RNEGx are fed to an internal XOR gate that
connects this output to RCLKx for external clock recovery.
5. Assuming a ±50 ppm Master Clock (MCLK).
Figure 5. LXT336 Receive Timing Diagram
tPW
RCLK
tPWH
tPWL
tSUR
tHR
RPOS
(CLKE=L)
RNEG
tSUR
tHR
RPOS
(CLKE=H)
RNEG
Datasheet
19
LXT336 — Quad T1/E1 Receiver
Figure 6. E1 Jitter Tolerance—G.823
1000 UI
Jitter
100 UI
LXT336 Jitter
Tolerance (typical)
18 UI
@ 1.7 Hz
10 UI
3.0 UI @ 2 kHz
ITU G.823, Mar 1993 (E1)
1 UI
.1 UI
1 Hz
0.8 UI
1.5 UI
@ 2.4 kHz
1.5 UI
@ 20 Hz
0.4 UI
0.2 UI
@ 18 kHz
10 Hz
100 Hz
1 kHz
10 kHz
100 kHz
Frequency
20
Datasheet
Quad T1/E1 Receiver — LXT336
Figure 7. T1 Jitter Tolerance—GR-499-CORE Category II
1000
Jitter Tolerance (UI)
100
LXT336 Jitter
Tolerance
(typical)
GR-499-CORE Category II
10
10 UI
@ 192.9 Hz
10 UI
@ 10 Hz
1
0.3 UI
@ 6.43 KHz
0.1
1
10
100
1000
10000
100000
Jitter Frequency (Hz)
Table 9.
Relevant Recommendations
Recommendation
Description
ITU
G.703
Physical/electrical characteristics of hierarchical digital interfaces
G.704
Functional characteristics of interfaces associated with network nodes
G.735
Characteristics of Primary PCM multiple equipment operating at 2048 kbit/s and offering
digital access at 384 kbit/s and/or synchronous digital access at 64 kbit/s
G.736
Characteristics of a synchronous digital multiplex equipment operating at 2048 kbit/s
G.775
Loss of signal (LOS) and alarm indication (AIS) defect detection and clearance criteria
G.823
The control of jitter and wander within digital networks which are based on the 2048 kbit/s
hierarchy
O.151
Specification of instruments to measure error performance in digital systems
ANSI
T1.102
Digital Hierarchy Electrical Interface
T1.231
Digital Hierarchy Layer 1 In-Service Digital Transmission Performance Monitoring
Bellcore
GR-499-CORE
Datasheet
Transport Systems Generic Requirements
21
LXT336 — Quad T1/E1 Receiver
5.0
Mechanical Specifications
Figure 8. Package Specifications
Quad Flat Pack
• Part Number: LXT336QE
• 64-pin QFP
• Extended Temperature Range -40°C - +85°C
D
D1
e
/2
for sides with even
number of pins
D3
θ3
E1
E3
L1
E
A2
A
θ
1
A1
θ3
B
L
Inches
Millimeters
Dim
Min
Max
Min
Max
A
–
0.130
–
3.30
A1
0.000
0.010
0.00
0.25
A2
0.100
0.120
2.55
3.05
b
0.012
0.018
0.30
0.45
D
0.695
0.715
17.65
18.15
D1
0.549
0.553
13.95
14.05
D3
0.472 REF.
12.00 REF.
E
0.695
0.715
17.65
18.15
E1
0.549
0.553
13.95
14.05
E3
e
L
L1
0.472 REF.
12.00 REF.
1
0.80 BSC1
0.031 BSC
0.029
0.041
0.73
0.077 REF.
1.03
1.95 REF.
q3
5°
16 °
5°
16 °
q
0°
7°
0°
7°
1. BSC: Basic Spacing between Centers.
22
Datasheet