XRT75R03IVTR-F Exar Corporation, XRT75R03IVTR-F Datasheet - Page 32

• Manufacturer Part Number: XRT75R03IVTR-F
• Description: IC LIU E3/DS3/STS-1 3CH 128LQFP
• Manufacturer: Exar Corporation

Specifications of XRT75R03IVTR-F

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XRT75R03
REV. 1.0.8
Redundancy is used to introduce reliability and protection into network card design. The redundant card in
many cases is an exact replicate of the primary card, such that when a failure occurs the network processor
can automatically switch to the backup card. EXAR’s R
for 1:1 and 1+1 redundancy applications. Without relays and one Bill of Materials, EXAR offers multi-port,
integrated LIU solutions to assist high density agregate applications and framing requirements with reliability.
The following section can be used as a reference for implementing R
line interface units.
A common network design that supports 1:1 or 1+1 redundancy consists of N primary cards along with N
backup cards that connect into a mid-plane or back-plane architecture without transformers installed on the
network cards. In addition to the network cards, the design has a line interface card with one source of
transformers, connectors, and protection components that are common to both network cards. Wtih this
design, the bill of materials is reduced to the fewest amount of components. See Figure 3 for a simplified block
diagram of a typical redundancy design.
F
EXAR’s "High" impedance circuits protect the LIU and preserve the line impedance characteristics when a
power failure occurs.
automatically switched to "High" impedance. This effectively removes the LIU, preventing a line impedance
mismatch or system degradation. Power failures or network card hot swapping change the network circuit. It
is critical that under these circumstances, that the primary card still behaves according to network standards.
The three sensitive specifications are pulse mask conformance, receive sensitivity and return loss. Each must
be carefully characterized to ensure network integrity and reliability.
The implementation of R
the use of the TxON hardware pin available within the LIU. To use software to tri-state the transmitters, first
the TxON pin must be pulled "High". Once the pin is pulled "High", the individual register bits can be used to
control the output activity of the transmit path. To use the TxON pin, the individual register bits can be set
"High", and the control of the transmitters is handled by setting the state of the TxON pin.
1.0 R
1.1
1.2
1.3
IGURE
3
3. N
Network Architecture
Power Failure Protection
Software vs Hardware Automatic Protection Switching
TECHNOLOGY (RECONFIGURABLE, RELAYLESS REDUNDANCY)
ETWORK
Primary Line Card
Redundant Line Card
Framer/
Mapper
Framer/
Mapper
THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
R
EDUNDANCY
As the power supply decreases to a pre-determined voltage, the I/O pads are
3
LIU
LIU
Rx
Tx
Rx
Tx
technology can be controlled through programming the internal registers or through
0.01 F
0.01 F
0.01 F
0.01 F
A
31.6
31.6
31.6
31.6
RCHITECTURE
Plane
Plane
Back
Mid
or
29
3
technology has re-defined E3/DS-3/STS-1 LIU design
GND
3
Technology with EXAR’s world leading
1:1
1:1
Line Interface Card
xr
xr
xr
xr