T1/E1 Short Haul Transceiver with Crystal-less Jitter Attenuation — LXT350
4.0
Application Information
4.1
Transmit Return Loss
Table 17 shows the specification for transmit return loss in E1 applications. The G.703/CH PTT
specification is a Swiss Telecommunications Ministry specification.
Table 18 and Table 19 show the transmit return loss values for E1 and T1 applications.
4.2
4.3
4.4
Transformer Data
Specifications for transformers are listed in Table 20. A list of transformers recommended for use
with the LXT350 are specified in Table 21.
Application Circuits
Figure 12 and Figure 13 show typical LXT350 applications for Hardware and Host modes of
operation.
Line Protection
On the receive side, 1 kΩ series resistors protect the receiver against current surges coupled into
the device. Due to the high receiver impedance (40 kΩ typical) the resistors do not affect the
receiver sensitivity. On the transmit side, Schottky diodes D1-D4 protect the output driver. While
not mandatory for normal operation, these protection elements are strongly recommended to
improve the design robustness.
Table 17. E1 Transmit Return Loss Requirements
Return Loss
Frequency Band
ETS 300 166
G.703/CH PTT
51-102 kHz
102-2048 kHz
2048 - 3072 kHz
6 dB
8 dB
8 dB
8 dB
14 dB
10 dB
Datasheet
33
ETC [ ETC ]
