Nortel Networks 1000 - Manual (Page 813)

Functional description 813
System clock specification and characteristics
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. See
Table 338 "System clock
specification and characteristics" (page 813) .
Table 338
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 0 to 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.
Table 339
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 0 to 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.
Table 340
System clock specification and characteristics
Specifications CCITT EIA
Base Frequency 20.48 MHz 20.48 MHz
Accuracy ±3 ppm ±1 ppm
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 02.06 Standard
27 August 2008
Copyright © 2003-2008 Nortel Networks
.