CMT2157AW
Rev 0.8 | Page 7/31
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1.4 Crystal Oscillator
Table 5. Crystal Oscillator Specifications
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Crystal Frequency
[1]
F
XTAL
26
26
26
MHz
Crystal Tolerance
[2]
±20
ppm
Load Capacitance
[3]
C
LOAD
12
20
pF
Crystal ESR
Rm
60
Ω
XTAL Startup Time
[4]
t
XTAL
400
us
Notes:
[1]. The CMT2157AW can directly work with external 26 MHz reference clock input to XTAL pin (a coupling capacitor is
required) with amplitude 0.3 to 0.7 Vpp.
[2]. This is the total tolerance including (1) initial tolerance, (2) crystal loading, (3) aging, and (4) temperature dependence.
The acceptable crystal tolerance depends on RF frequency and channel spacing/bandwidth.
[3]. The required crystal load capacitance is integrated on-chip to minimize the number of external components.
[4]. This parameter is to a large degree crystal dependent.
