Evaluation Board for Quad T1/E1 Applications — LXD386
Figure 5. Jumper Block JP 31
3.13LED Indicators
Loss of Signal (LOS) status for each channel is indicated by four LEDs, labeled D3 through D6. If the board is being used in the Software mode, the state of these LEDs will also be displayed on the registers display screen.
3.14Line Interface
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.
An octal transformer is used for channels 1 to 3 (one transformer port is unused). Transformers in channel 0 and line resistors /capacitors for channels 0 to 3 are socketed for easy swapping. Jumpers JP7 to JP14 can be used to bypass the transmit series resistors for T1 applications with TVCC=3.3V. See the LXT386 Data Sheet for details on transmit interface options.
3.15Board Protection
The LXD386 evaluation board is equipped with both power supply and line surge protection. Two Transient Voltage Suppressors (TVS) are included for power supply protection (5V/3.3V). For the T1/E1 line interface, the transmitters are protected with Schottky diodes and the receivers are protected by series 1KΩ input resistors. This protection is sufficient for G.703 Annex B compliance.
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