WJLXT385LE.B1 Cortina Systems Inc, WJLXT385LE.B1 Datasheet - Page 60

• Manufacturer Part Number: WJLXT385LE.B1
• Manufacturer: Cortina Systems Inc

Specifications of WJLXT385LE.B1

• Lead Free Status / RoHS Status: Supplier Unconfirmed

6.4.3
60
Intel
®
LXT385 Octal E1 S/H PCM Transceiver with JA
Note:
6.4.2.1
6.4.2.2
The output driver power supply (TVCC pins) can be either 3.3V or 5V nominal.
The Channel 4 (TVCC4) power supply pin sets 3.3V or 5.0V transmit operation. See
Seriesresistors in the transmit configuration improve the transmit return loss performance. Good
transmit return loss performance minimizes reflections in harsh cable environments. In addition,
series resistors provide protection against surges coupled to the device. The resistors should be
used in systems requiring protection switching without external relays. Refer
recommended external line circuitry.
For the LXT385 ransceiver, sequence TVCC first, then VCC second or at the same time as TVCC,
to prevent excessive current draw.
Transmitter Outputs
A transmitter transmits output signals as follows:
If TCLK is not supplied, the transmitter is in a powered-down state and the TTIP and TRING
outputs are held in a low-power high-impedance tristate.
1. Through a step-up transformer, a transmitter transmits an output signal, typically to either a
2. One polarity of the output signal (the positive pulse) is transmitted at TTIP, and the other
•
•
When TVCC=5V, theLXT385 ransceiver drives 75Ω/120Ω lines through a 1:2 transformer
and 11Ω/9.1Ω series resistors.
When TVCC=3.3V, the LXT385 ransceiver drives 75Ω/120Ω lines through a 1:2 transformer
and 11Ω series resistor.
twisted-pair or a coaxial cable. (For transformer specifications,
“Line-Interface-Unit Circuit
polarity (the negative pulse) is transmitted at TRING.
Output Driver Power Supply
Power Sequencing
Specifications”.)
seeFigure 6
toFigure 6
Revision Date: 19-Jan-2006
Document Number: 249252
and
Revision Number: 006
Chapter 12.0,
Table
for the
18.