XRT7302IV View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT7302IV' PDF : 62 Pages View PDF
XRT7302 2 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. 1.1.6
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PRELIMINARY
FIGURE 20. THE SIGNAL LEVELS AT WHICH THE XRT7302 DECLARES AND CLEARS LOS
0 dB
-12 dB
-15dB
LOS Signal Must be Cleared
Maximum Cable Loss for E3
-35dB
LOS Signal may be Cleared or Declared
LOS Signal Must be Declared
Timing Requirements associated with Declaring
and Clearing the LOS Indicator
The XRT7302 was designed to meet the ITU-T G.775
specification timing requirements for declaring and
clearing the LOS indicator. In particular, a channel of
the XRT7302 declares an LOS between 10 and 255
UI (or E3 bit-periods) after the actual time the LOS
condition occurred. The channel clears the LOS indi-
cator within 10 to 255 UI after restoration of the in-
coming line signal. Figure 21 illustrates the LOS Dec-
laration and Clearance behavior in response to the
Loss of Signal event and then the restoration of the
signal.
FIGURE 21. THE BEHAVIOR THE LOS OUTPUT INDICATOR IN RESPONSE TO THE LOSS OF SIGNAL AND THE RESTO-
RATION OF SIGNAL
RTIP/
RRing
Actual Occurrence
of LOS Condition
Line Signal
is Restored
10 UI
255 UI
Time Range for
LOS Declaration
10 UI
255 UI
RLOS Output Pin
0 UI
G.775
Compliance
0 UI
Time Range for
LOS Clearance
G.775
Compliance
38
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