XRT83VSH28IB-F View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT83VSH28IB-F' PDF : 74 Pages View PDF
XRT83VSH28
PRELIMINARY
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
REV. P1.0.0
The driver monitor circuit is used to detect transmit driver failures by monitoring the activities at TTIP/TRING
outputs. Driver failure may be caused by a short circuit in the primary transformer or system problems at the
transmit inputs. If the transmitter of a channel has no output for more than 128 clock cycles, DMO goes "High"
until a valid transmit pulse is detected. If the DMO interrupt is enabled, the change in status of DMO will cause
the interrupt pin to go "Low". Once the status register is read, the interrupt pin will return "High" and the status
register will be reset (RUR).
3.7 Line Termination (TTIP/TRING)
The output stage of the transmit path generates standard return-to-zero (RZ) signals to the line interface for E1
twisted pair or E1 coaxial cable. The physical interface is optimized by placing the terminating impedance
inside the LIU. This allows one bill of materials for all modes of operation reducing the number of external
components necessary in system design. The transmitter outputs only require one DC blocking capacitor of
0.68µF. For redundancy applications (or simply to tri-state the transmitters), set TxTSEL to a "1" in the
appropriate channel register. A typical transmit interface is shown in Figure 19.
FIGURE 19. TYPICAL CONNECTION DIAGRAM USING INTERNAL TERMINATION
XRT83VSH28 LIU
TTIP
Transmitter
Output
TRING
Internal Impedance
1:2
C=0.68uF
Line Interface E1
One Bill of Materials
31
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