PRELIMINARY
CYW43340
Figure 5. Recommended Circuit to Use with an External Dedicated TCXO
1000 pF
TCXO
WRF_XTAL_OP
WRF_XTAL_ON
WRF_TCXO_CK
WRF_TCXO_VDD
NC
Figure 6. Recommended Circuit to Use with an External Shared TCXO
To other devices
TCXO
WRF_TCXO_CK
WRF_TCXO_VDD
WRF_XTAL_OP
To always present 1.8V supply
WRF_XTAL_ON
NC
Table 3. Crystal Oscillator and External Clock – Requirements and Performance
Crystala
External Frequency
Referenceb,c
Typ
Parameter
Conditions/Notes
Min
Typ
Max
Min
Max
Units
pF
Frequency
–
–
–
Between 19.2 MHz and 52 MHzd,e
Crystal load capacitance
ESR
–
12
–
–
–
–
–
–
–
–
–
60
–
–
–
Ω
Drive level
External crystal requirement
Resistive
200f
30k
–
–
–
–
µW
Ω
Input impedance
(WRF_XTAL_OP)
100k
–
30k
–
100k
Capacitive
–
–
–
–
7.5
–
–
7.5
–
pF
Ω
Input impedance
(WRF_TCXO_IN)
Resistive
–
30k
–
100k
Capacitive
–
–
–
–
4
pF
V
WRF_XTAL_OP
Input low level
DC-coupled digital signal
–
–
0
0.2
WRF_XTAL_OP
Input high level
DC-coupled digital signal
–
–
–
–
–
–
–
–
–
1.0
–
–
–
1.26
1200
1980
V
WRF_XTAL_OP
input voltage
AC-coupled analog signal
(see Figure 5)
400
400
mVp-p
mVp-p
WRF_TCXO_IN
Input voltage
DC-coupled analog signal
(see Figure 6)
Document Number: 002-14943 Rev. *L
Page 12 of 96
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