dp83630sqx National Semiconductor Corporation, dp83630sqx Datasheet - Page 38

• Manufacturer Part Number: dp83630sqx
• Description: Precision Phyter - Ieee 1588 Precision Time Protocol Transceiver
• Manufacturer: National Semiconductor Corporation

www.national.com
maximum of 500 µW. If a crystal is specified for a lower drive
level, a current limiting resistor should be placed in series be-
tween X2 and the crystal.
As a starting point for evaluating an oscillator circuit, if the
requirements for the crystal are not known, C
should be set at 33 pF, and R
Specification for 25 MHz crystal are listed in
Note 2: This limit is provided as a guideline for component selection and not guaranteed by production testing. Refer to AN-1548, “PHYTER 100 Base-TX
Reference Clock Jitter Tolerance,” for details on jitter performance.
Note 3: This limit is provided as a guideline for component selection and not guaranteed by production testing. Refer to AN-1548, “PHYTER 100 Base-TX
Reference Clock Jitter Tolerance,” for details on jitter performance.
Frequency Tolerance
Frequency Tolerance
Frequency Tolerance
Frequency Stability
Frequency Stability
Frequency Stability
Shunt Capacitance
Rise / Fall Time
Rise / Fall Time
Parameter
Parameter
Parameter
Frequency
Frequency
Frequency
Symmetry
Symmetry
Jitter
Jitter
Jitter
Jitter
1
should be set at 0 Ω.
40%
Min
40%
Min
Min
25
TABLE 10. 50 MHz Oscillator Specification
TABLE 9. 25 MHz Oscillator Specification
TABLE 11. 25 MHz Crystal Specification
Table
L1
11.
Typ
Typ
Typ
and C
25
50
25
L2
800
800
800
800
38
Max
Max
60%
60%
±50
±50
(Note
(Note
±50
±50
(Note
(Note
±50
±50
Max
40
6
6
2)
2)
3)
3)
Units
Units
FIGURE 11. Crystal Oscillator Circuit
nsec
psec
psec
nsec
psec
psec
Units
MHz
ppm
ppm
MHz
MHz
ppm
ppm
ppm
ppm
pF
Operational Temperature
Operational Temperature
Operational Temperature
Operational Temperature
Range of C
1 year aging
1 year aging
Condition
Condition
20% - 80%
Duty Cycle
20% - 80%
Duty Cycle
Short term
Short term
Condition
Long term
Long term
L1
and C
30136213
L2