lxt6155 Intel Corporation, lxt6155 Datasheet - Page 33

• Manufacturer Part Number: lxt6155
• Description: 155 Mbps Sdh/sonet/atm Transceiver
• Manufacturer: Intel Corporation

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4.1
4.2
Datasheet
Application Information
The following provides application examples of interfacing the LXT6155 to the line side and the
overhead terminator side. Line side encoding schemes can be one of two types: LVPECL NRZ
encoded for a fiber optic module, or CMI encoded for a 75 coax cable. On the systems side, serial
differential or parallel eight-bit modes can be used. All signals are TTL level compatible, except
serial interface signals (TPOS, TNEG, TSICLKP, TSICLKN, RSOCLKP, RSOCLKN, RPOS, and
RNEG) which are 3.3V LVPECL compatible.
Fiber Optic Module Interface
The LXT6155 is designed to directly drive a 3.3V LVPECL fiber optic transceiver. The LVPECL
drivers require the proper transmission line impedance to correctly drive the fiber module. Signal
traces should be 50
Please refer to Figure 16 for the proper interface.
To interface the LXT6155 LVPECL signals to a 5V PECL fiber optic module, please refer to the
LXT6155 application note AN141.
Coax Interface
As shown in 17 on page 35, the LXT6155 directly drives a transformer connected to a 75
cable, up to12.7dB cable loss at 78MHz. This is approximately 110m of RG59U. Please refer to
manufacturers specifications for maximum cable lengths. Output CMI waveform conform to the
ITU G.703 specifications. Rise and fall times are less than 2.0 ns.
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controlled impedance lines and should be biased to the appropriate level.
155 Mbps SDH/SONET/ATM Transceiver — LXT6155
coaxial
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