MC145572 Datasheet, PDF (207/264 Pages) Freescale Semiconductor, Inc – ISDN U-INTERFACE TRANSCEIVER

B.3.1
Freescale Semiconductor, Inc.
Pullable Crystal Specification for ISDN and Network Applications
1. Operating frequency:
2. Crystal shunt capacitance:
3. Uncertainty at rated CL:
4. Equivalent series resistance:
5. Crystal pull range:
a. ± 5 ppm signal
b. ± 32 ppm signal
c. ± 50 ppm signal
6. Calibration load capacitance:
20.48 MHz
Co = 7.0 pF
± 50 ppm over temperature, calibration, and 10–year aging
RS ≤ 20 ohms @ 1 mW drive
200 ppm minimum pullability over a CL range of 15 to 45 pF
260 ppm minimum pullability over a CL range of 15 to 45 pF
300 ppm minimum pullability over a CL range of 15 to 45 pF
24 pF
NOTES:
1. – 40 to + 85°C required for transmission applications.
2. For room temperature, use 0 to 70°C.
3. Explanation of item 5, crystal pull range. Crystal pullability must be specified to allow the MC145572 to lock to either a re-
ceived signal when operating in NT mode or lock to the 8 kHz FREQREF when operating in LT mode. The appropriate crystal
pullability specification is dependent of the maximum expected signal or FREQREF tolerance in ppm. This will vary depend-
ing on national network and application requirements. For example in North America, receive signals from the network are
expected to have a tolerance of less than 5 ppm. Hence, a crystal with either 200 or 260 ppm total pullability may be used.
The ultimate choice is up to the equipment designer.
B.4
CRYSTAL SOURCES
Table B–3 lists sourcing information for the crystals used in the MC145572.
Table B–3. Crystal Vendors
Manufacturer
Contact Phone No.
ECLIPTEK
(714) 433–1200
Hy–Q International
(606) 283–5000
SaRonix
(415) 856–6900
Connor–Winfield
(708) 851–4722
Precision Devices
(608) 831–4445
NOTE: See Caution note on page B–1.
Contact Fax No.
(714) 433–1234
(606) 283–0883
(415) 856–4732
(708) 851–5040
(608) 831–3343
MOTOROLA
For More InforMmCa1t4io55n7O2 n This Product,
B–3
Go to: www.freescale.com