
Data Sheet
100604B
March 23, 2000
Advance Information
This document contains information on a product under development. The parametric information 
contains target parameters that are subject to change.
CN8331/CN8332/CN8333
Single/Dual/Triple E3/DS3/STS-1 Line Interface Unit
The CN8333 is a three-channel, E3/DS3/STS-1 fully-integrated Line Interface Unit (LIU). 
It is configured via external pins and does not need a microprocessor interface. 
Eachchannel has an independent equalizer on the receive side requiring no user 
configuration. Also, each channel has a programmable transmit pulse shaper that can 
be set to ensure that the cross-connect pulse mask requirement is met for transmit 
cable length up to 450 feet. The CN8332 is a dual-channel, and the CN8331 is a 
single-channel LIU with performance identical to the CN8333.
The CN8333 gives the user new economies of scale in concentrator applications 
where three DS3 or STS-1 channels are concentrated into a single STS-3 channel. By 
including three independent transceivers on a chip, significant external components are 
eliminated, with the exception of 1:1 coupling transformers, termination resistors, and 
supply bypass capacitors.
NOTE:
 In this document "x" is used to represent the number of channels: 
x=1 (CN8331), x = 2 (CN8332), and x = 3 (CN8333).
Functional Block Diagram (only one Channel is shown)
TPOS
TNEG
TCLK
ENCODER
TAIS
Pulse
Shaper
E3MODE
LINE
DRIVER
PDB
DATA
MUX
RLOOP
LLOOP
E
LBO
XOE
TLINEP
TLINEM
DECODER
RPOS
RNEG
RCLK
RLOS
TCLK
Clock/
Data
Recovery
PDATA
NDATA
DATCLK
P
N
Receiver
ALOS
RLINEP
RLINEM
REFCLK
REQH
Distinguishing Features
Can be used as a data transceiver 
over a maximum of 900 feet of Type 
734/728 coaxial cable or equivalent 
in an on-premise environment
Programmable pulse filtering to meet 
cross-connect pulse masks (
ANSI 
T1.102-1993
)
Meets jitter specifications of 
Bellcore 
GR499 
and GR253
Large input dynamic range
Alarms for coding violation and loss 
of signal
Full diagnostic loopback capability
Uses a minimum of external 
components
Compatible with 
ITU-T G.703, G.823
Independent power down mode per 
channel
Easily interfaced to the DS3/E3 
Framer IC (CN8342/3/4/6/8 and 
CN8330)
Selectable B3ZS/HDB3 
encoding/decoding
Superior input receiver sensitivity 
(<25mV)
Physical Characteristics
80-pin ETQFP package
Single 3.3 V power supply
1 W maximum power dissipation 
(CN8333)
–
40 
°
C to +85 
°
C temperature range
5 V-tolerant pins
TTL digital pins
Applications
Digital Cross Connect Systems
Routers
ATM Switches
Channelized Line Aggregation Units
Test Equipment
Channel Service Units
Multiplexers
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