XRT75L04 Datasheet, PDF (7/57 Pages) Exar Corporation – FOUR CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER

XRT75L04
REV. 1.0.4
FOUR CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
TRANSMIT INTERFACE
PIN #
SIGNAL NAME
TYPE
DESCRIPTION
45
TPOS_0
33
TPOS_1
176
TPOS_2
12
TPOS_3
I Transmit Positive Data Input - Channel 0:
Transmit Positive Data Input - Channel 1:
Transmit Positive Data Input - Channel 2:
Transmit Positive Data Input - Channel 3:
By default sampled on the falling edge of TxCLK
41
TTIP_0
29
TTIP_1
4
TTIP_2
16
TTIP_3
O Transmit TTIP Output - Channel 0:
Transmit TTIP Output - Channel 1:
Transmit TTIP Output - Channel 2:
Transmit TTIP Output - Channel 3:
These pins along with TRING transmit bipolar signals to the line using a 1:1
transformer.
39
TRING_0
27
TRING_1
6
TRING_2
18
TRING_3
O Transmit Ring Output - Channel 0:
Transmit Ring Output - Channel 1:
Transmit Ring Output - Channel 2:
Transmit Ring Output - Channel 3:
These pins along with TTIP transmit bipolar signals to the line using a 1:1 trans-
former.
50
TxLEV_0
47
TxLEV_1
171
TxLEV_2
174
TxLEV_3
I
Transmit Line Build-Out Enable/Disable Select - Channel 0:
Transmit Line Build-Out Enable/Disable Select - Channel 1:
Transmit Line Build-Out Enable/Disable Select - Channel 2:
Transmit Line Build-Out Enable/Disable Select - Channel 3:
These input pins are used to select the Transmit Line Build-Out circuit of Chan-
nel n.
Setting these pins to "High" disables the Line Build-Out circuit of Channel n. In
this mode, Channel n outputs partially-shaped pulses onto the line via the
TTIP_n and TRing_n output pins.
Setting these pins to "Low" enables the Line Build-Out circuit of Channel n. In
this mode, Channel n outputs shaped pulses onto the line via the TTIP_n and
TRing_n output pins.
To comply with the Isolated DSX-3/STSX-1 Pulse Template Requirements per
Bellcore GR-499-CORE or Bellcore GR-253-CORE:
1. Set these pins to "1" if the cable length between the Cross-Connect and the
transmit output of Channel is greater than 225 feet.
2. Set these pins to "0" if the cable length between the Cross-Connect and the
transmit output of Channel is less than 225 feet.
These pins are active only if the following two conditions are true:
a. The XRT75L04 is configured to operate in either the DS3 or SONET STS-1
Modes.
b. The XRT75L04 is configured to operate in the Hardware Mode.
NOTES:
1. These pins are internally pulled down.
2. If the XRT75L04 is configured in HOST mode, these pins should be
tied to GND.
5