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XTAL
Table 18-3 Crystal Resonator Characteristics
Frequency (MHz)
max (Ω Ω Ω Ω )
R
S
C
max (pF)
0
Notes on Board Design: When a crystal resonator is connected, the following points should be
noted:
Other signal lines should be routed away from the oscillator circuit to prevent induction from
interfering with correct oscillation. See figure 18-4.
When designing the board, place the crystal resonator and its load capacitors as close as possible
to the XTAL and EXTAL pins.
Avoid
C
L
C
Figure 18-3 Crystal Resonator Equivalent Circuit
2
4
500
120
7
7
Signal A Signal B
C
L2
C
L1
Figure 18-4 Example of Incorrect Board Design
L
R
s
EXTAL
AT-cut parallel-resonance type
0
8
12
80
60
7
7
Chip
XTAL
EXTAL
Rev. 5.00, 12/03, page 773 of 1088
16
20
25
50
40
40
7
7
7
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