Table 19-24. Ethernet Reference Crystal
a
ConditionValueName
MHz25.00000Frequency
PPM±50Frequency tolerance
PPM/yr±2Aging
PPM±5Temperature stability (-40° to 85°)
PPM±5Temperature stability (-40° to 105°)
Parallel resonance, fundamental
mode
Oscillation mode
Parameters at 25° C ±2° C; Drive level = 0.5 mW
µW50-100Drive level (typ)
pF10Shunt capacitance (max)
fF10Motional capacitance (min)
Ω60Series resistance (max)
> 5 dB below main within 500 kHzSpurious response (max)
a. If the internal crystal oscillator is used, select a crystal that meets these specifications.
Figure 19-14. External XTLP Oscillator Characteristics
Table 19-25. External XTLP Oscillator Characteristics
UnitMaxNomMinSymbolParameter Name
-0.8--XTLN
ILV
XTLN Input Low Voltage
--25.0-XTLP
f
XTLP Frequency
a
--40-T
clkper
XTLP Period
b
%60
60
-40
40
XTLP
DC
XTLP Duty Cycle
ns4.0--T
r
, T
f
Rise/Fall Time
ns0.1--T
JITTER
Absolute Jitter
a. IEEE 802.3 frequency tolerance ±50 ppm.
b. IEEE 802.3 frequency tolerance ±50 ppm.
June 22, 2010498
Texas Instruments-Production Data
Electrical Characteristics