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2.0 Functional Description
2.1 Overview
CX28333 is a triple E3/DS3/STS-1 Line Interface Unit (LIU). It is the physical
layer interface between the data framer (or other terminal-side equipment) and the
electrical cable used for data transmission.
The CX28333 LIU consists of three independent data transceivers that can
operate over type 734/728 coaxial cable at the rates of 34.368 Mbps (E3), 44.736
Mbps (DS3), and 51.84 Mbps (STS-1). The transmit side takes an NRZ or
already-encoded dual rail input and encodes it into AMI B3ZS (for DS3/STS-1)
or HDB3 (for E3) analog waveforms to be transmitted over the coaxial cable. The
receiver side takes in the attenuated and distorted analog receive signal and
equalizes, slices, and resynchronizes the signal before decoding it to the NRZ
output or sending out a non-decoded dual rail.
CX28331 and CX28332 are single- and dual-E3/DS3/STS-1 LIUs,
respectively. In all respects, their performance and features are identical to the
CX28333.
The architecture of the CX2833i includes the following internal functions for
each channel:
Transmitter:
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AMI B3ZS/HDB3 encoder
pulse shaper
line driver
Alarm Indication Signal (AIS) insertion
transmit monitor
Receiver:
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receive sensitivity
Automatic Gain Control (AGC)
receive equalizer
Clock Recovery circuit
Loss Of Signal (LOS) detector
B3ZS/HDB3 decoder with bipolar violation detector
data squelching
100985A
Conexant
2-1
CONEXANT [ CONEXANT SYSTEMS, INC ]
