WJLXT384LE.B1-868635 Cortina Systems Inc, WJLXT384LE.B1-868635 Datasheet - Page 54

• Manufacturer Part Number: WJLXT384LE.B1-868635
• Manufacturer: Cortina Systems Inc

Specifications of WJLXT384LE.B1-868635

• Screening Level: Industrial
• Mounting: Surface Mount
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Lead Free Status / RoHS Status: Compliant

LXT384 Transceiver
Datasheet
248994, Revision 6.0
30 January 2008
Cortina Systems
For some power-up operations, on rare occasions there is no activity for several seconds on
all of the following transmit-side pins: TPOS, TNEG, TCLK, and MCLK. If this lack of activity
occurs for a period of several seconds, then it can cause transmitter outputs to remain in
their last-known logic state. If the transmitter outputs are in static mode. As a result, then the
transformer output appears as a short circuit to this static DC voltage.
In the worst case of inactivity, one of the transmitter outputs is high while other transmitter
outputs are low. In this case, outputs TTIP and TRING would draw excessive current
through the transformer primary windings and the LXT384 Transceiver can overheat. To
manage this type of power-up operation, do only one of the following:
®
• Set OE low until normal operations return.
• Set TCLK low until normal operations return.
• Set TNEG low until normal operations return.
• Set TPOS low until normal operations return.
• Provide MCLK with a frequency from 10 kHz to 10 MHz until normal operations return.
• Provide TCLK with a frequency from 100 kHz to 10 MHz until normal operations return.
• Toggle TNEG with a clock from 100 kHz to 10 MHz until normal operations return.
• Toggle TPOS with a clock from 100 kHz to 10 MHz until normal operations return.
• As shown in
LXT384 Octal T1/E1/J1 Short-Haul PCM Transceiver with Jitter Attenuation (JA)
resistors.
Figure
6, add a single 0.47 μF capacitor in series with one of the R
TM
TM
6.5 Line-Interface Protection
T
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output