Description
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2.4.5.1.1 6.4 MHz pilot reference
This function carries out the following:
• the generation of the 6.4 MHz reference signal,
• the selection of the internal or external reference clock according to the master or slave
configuration.
2.4.5.1.2 Clocks and synchros
This function provides the generation, from the 6.4 MHz reference frequency, of the
following clocks for the 3G PA-TRX module:
• 20 ms synchronisation clock (HS),
• 64 kHz transmission clock (HT).
2.4.5.1.3 TTL / V11 conversion
This function converts the TTL type clock and synchronisation signals into V11 electrical
signals.
2.4.5.1.4 3V3L and 3V3 power supplies and alarms
This function carries out the following:
• the 3V3L voltage intended to power the synchronisation board's logical circuits,
• the 3V3 voltage, specific voltage for the TCXO, carried out from a linear series regulator
to have no background noise that may disrupt the TCXO,
• the fan and convertor module power supply alarm interface.
2.4.5.1.5 Fan management interface
This function carries out the following:
• fan power supply (48 V),
• the slaving of the fan rotation speed according to the rack's internal temperature,
• the tachymetric interface and the minimum rotation detection to generate the fan alarm.
