XRT7302IQ80 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT7302IQ80' PDF : 77 Pages View PDF
XRT7302 2 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. 1.1.0
.
FIGURE 17. ILLUSTRATION OF THE TYPICAL APPLICATION FOR THE SYSTEM INSTALLER
áç
Transmitting
Terminal
0 to 450 feet of
Cable
Digital Cross-Connect
System
DSX-3
or
STSX-1
Pulses that are
compliant to the
Isolated DSX-3 or
STSX-1 Pulse Template
Requirement
0 to 450 feet of Cable
Receiving
Terminal
3.2 THE RECEIVE EQUALIZER BLOCK
Design Considerations (for DS3 and STS-1 Appli-
cations)
When installing equipment into environments as de-
picted in Figure 17, we recommend that the user en-
able the Receive Equalizer, by setting the "REQEN1"
input pin (for Channel 1) or the "REQEN2" input pin
(for Channel 2) “high”, or the respective bit-fields to
"1". In fact, the only time that the user should disable
the Receive Equalizer is when an off-chip equalizer is
in the Receive path between the Digital Cross-Con-
nect system and the RTIP/RRing input pins, or in ap-
plications where the Receiver is monitoring the trans-
mit output signal directly.
Design Considerations (for E3 Applications or if
the Overall Cable Length is known)
Figure 17 indicates the following.
a. That the length of cable between the Transmitting
Terminal and the Digital Cross-Connect system can
range between 0 and 450 feet.
b. That the length of cable between the Digital Cross-
Connect system and the Receive Terminal can range
between 0 and 450 feet.
As a consequence, the overall cable length (between
the Transmitting Terminal and the Receiving Terminal)
can range between very short cable length (e.g., near
0 feet) up to 900 feet.
If, during System Installation, the overall cable length
is known, then (in order to optimize the performance
of the XRT7302 device, in terms of receive jitter per-
formance, etc.) the user should enable or disable the
Receive Equalizer, based upon the following recom-
mendations.
As a guideline, the Receive Equalizer should be
"turned ON", if the Receive Section (of a given chan-
nel) is going to receive a line signal with an overall ca-
ble length of 300 feet or greater. Conversely, the Re-
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