Nortel Networks 311 - page 913

Functional description 913
Table373
System clock specification and characteristics
Specifications CCITT EIA
Base Frequency 20.48 MHz 20.48 MHz
Accuracy ±3 ppm ±1 ppm
Operating Temperature 0 to 70 C ±1 ppm 0to 70 C ±1 ppm
Drift Rate (Aging) ±1 ppm per year ±4 ppm in 20 years
±60 ppm min. ±10 ppm min.Tuning Range (minimum)
±90 ppm max. ±15 ppm max.
Input Voltage Range 0 to 10 volts, 5V center 0 to 10 volts, 5V center
Since the accuracy requirements for CCITT and EIA Stratum 3ND are so
different, it is necessary to have two TCVCXO which feature different values
of frequency tuning sensitivity.
Table374
System clock specification and characteristics
Specifications CCITT EIA
Base Frequency 20.48 MHz 20.48 MHz
Accuracy ±3 ppm ±1 ppm
Operating Temperature 0 to 70 C ±1 ppm 0to 70 C ±1 ppm
Drift Rate (Aging) ±1 ppm per year ±4 ppm in 20 years
±60 ppm min. ±10 ppm min.Tuning Range (minimum)
±90 ppm max. ±15 ppm max.
Input Voltage Range 0 to 10 volts, 5V center 0 to 10 volts, 5V center
Since the accuracy requirements for CCITT and EIA Stratum 3 are different,
it is necessary to have two TCVCXOs which feature different values of
frequency tuning sensitivity.
Table375
System clock specification and characteristics
Specifications CCITT EIA
Base Frequency 20.48 MHz 20.48 MHz
Accuracy ±3 ppm ±1 ppm
Operating Temperature 0 to 70 C ±1 ppm 0to 70 C ±1 ppm
Drift Rate (Aging) ±1 ppm per year ±4 ppm in 20 years
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23May 2008
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