xrt83l30 Exar Corporation, xrt83l30 Datasheet - Page 14

• Manufacturer Part Number: xrt83l30
• Description: Xrt83l30 -single-channel T1/e1/j1 Long-haul, Short-haul Line Interface Unit
• Manufacturer: Exar Corporation

REDUNDANCY SUPPORT
TERMINATIONS
XRT83L30
SINGLE-CHANNEL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
S
S
IGNAL
IGNAL
RXTSEL
TXTSEL
GAUGE
TRATIO
DMO
N
N
AME
AME
P
P
11
49
26
44
45
IN
IN
#
#
T
T
YPE
YPE
O
I
I
I
I
Driver Failure Monitor
This pin transitions "High" if a short circuit condition is detected in the trans-
mit driver, or no transmit output pulse is detected for more than 128 TCLK
cycles.
Twisted Pair Cable Wire Gauge Select
In Hardware mode, connect this pin "High" to select 26 Gauge wire. Connect
this pin “Low” to select 22 and 24 gauge wire.
N
Transmitter Transformer Ratio Select
In external termination mode, setting this pin "High" selects a transformer
ratio of 1:2 for the transmitter. A "Low" on this pin sets the transmitter trans-
former ratio to 1:2.45. In the internal termination mode the transmitter trans-
former ratio is permanently set to 1:2 and the state of this pin is ignored.
N
Receiver Termination Select
In Hardware mode when this pin is “Low” the receive line termination is
determined only by the external resistor. When “High”, the receive termina-
tion is realized by internal resistors or the combination of internal and exter-
nal resistors according to RXRES[1:0]. These conditions are described in the
following table:
N
Transmit Termination Select
In Hardware mode when this pin is “Low” the transmit line termination is
determined only by external resistor. When “High”, the transmit termination is
realized only by an internal resistor. These conditions are summarized in the
following table:
N
OTE
OTE
OTE
OTE
: Internally pulled “Low” with a 50kΩ resistor.
: Internally pulled "Low" with a 50kΩ resistor.
: This pin is internally pulled "Low" with a 50kΩ resistor.
: This pin is internally pulled "Low" with a 50kΩ resistor.
11
RXTSEL
TXTSEL
0
1
0
1
D
D
ESCRIPTION
ESCRIPTION
RX Termination
TX Termination
External
External
Internal
Internal
REV. 1.0.1