Filter
Top Products
Evaluation Board for Octal E1 Applications — LXD381
Developer Manual 9
2.9 Line Interface Connection
Access to the line interface is provided through the green and white banana jacks. The TIP signal is
routed to the white jacks for both transmit and receive directions. The RING signal is routed to the
green jacks for both directions.
2.10 Line Interface Circuit
Two octal transformers are used for channels 0 to 3 and 4 to 7. Transformers, resistors and
capacitors for channels 0 and 4 are socketed for easy swapping (see the LXT381 data sheet for line
interface information). Jumper blocks are provided to configure the receive transformer operation
for 1:1 or 1:2 turns ratio (see “Evaluation Board Schematics” on page 10). Factory installed
jumpers configure the transformers for a 1:1 ratio.
2.11 Board Protection
The evaluation board provides line surge protection for both the power supply and the line. Two
transient voltage suppressors (TVS) are included for power supply protection. The E1 line interface
transmitters are protected with Schottky diodes and the receivers are protected by series input
resistors. This protection is sufficient for G.703 Annex B compliance.
Figure 3. Typical Back-End Connector
12
34
56
78
GND
RCLK 0
RPOS 0
RNEG 0
TCLK 0
TCLK 0
TPOS 0
TNEG 0
JP1
9
10
GNDLOS 0