XRT73L03 Datasheet, PDF (9/62 Pages) Exar Corporation – 3 CHANNEL E3/DS3/STS-1 LINE INTERFCE UNIT

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PRELIMINARY
PIN DESCRIPTION
PIN #
34
SIGNAL NAME
TxClk1
35
TxLEV1
36
TAOS1
37
TxAVDD1
38
DMO1
39
TxAGND1
40
AGND1
3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT XRT73L03
REV. P1.0.13
TYPE
I
I
I
****
O
****
****
DESCRIPTION
Transmit Clock Input for TPData and TNData - Channel 1:
This input pin must be driven at 34.368 MHz for E3 applications, 44.736 MHz
for DS3 applications or 51.84 MHz for SONET STS-1 applications. The
XRT73L03 uses this signal to sample the TPData1 and TNData1 input pins.
By default, the XRT73L03 is configured to sample these two pins on the falling
edge of this signal.
If operating in the HOST Mode, the XRT73L03 can be configured to sample
the TPData1 and TNData1 input pins on either the rising or falling edge of
TxClk1.
Transmit Line Build-Out Enable/Disable Select - Channel 1:
This input pin is used to enable or disable the Transmit Line Build-Out circuit of
Channel 1.
Setting this pin to "High" disables the Line Build-Out circuit of Channel 1. In
this mode, Channel 1 outputs partially-shaped pulses onto the line via the
TTIP1 and TRing1 output pins.
Setting this pin to "Low" enables the Line Build-Out circuit of Channel 1. In this
mode, Channel 1 outputs shaped pulses onto the line via the TTIP1 and
TRing1 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 this input pin to "1" if the cable length between the Cross-Connect and
the transmit output of Channel 1 is greater than 225 feet.
2. Set this input pin to "0" if the cable length between the Cross-Connect and
the transmit output of Channel 1 is less than 225 feet.
This pin is active only if the following two conditions are true:
a. The XRT73L03 is configured to operate in either the DS3 or SONET STS-1
Modes.
b. The XRT73L03 is configured to operate in the Hardware Mode.
NOTE: If the XRT73L03 is going to be operating in the HOST Mode, this pin
should be tied to GND.
Transmit All Ones Select - Channel 1:
A “High" on this pin causes the Transmit Section of Channel 1 to generate and
transmit a continuous AMI all “1’s" pattern onto the line. The frequency of this
"1’s" pattern is determined by TxClk1.
NOTES:
1. This input pin is ignored if the XRT73L03 is operating in the HOST
Mode.
2. if the XRT73L03 is going to be operating in the HOST Mode, this pin
should tie tied to GND..
Transmitter Analog 3.3V+ 5% VDD - Transmitter 1
Drive Monitor Output - Channel 1:
If no transmitted AMI signal is present on MTIP1 and MRing1 input pins for
128±32 TxClk periods, then DMO1 toggles and remains "High" until the next
AMI signal is detected.
Transmitter Analog GND - Transmitter 1
Analog GND (Substrate Connection) - Channel 1:
6