845
XTAL
C
L
AT-cut parallel-resonance type
EXTAL
C
0
L
R
s
Figure 23-3 Crystal Resonator Equivalent Circuit
Table 23-3 Crystal Resonator Parameters
Frequency (MHz) 2
4
8
12
16
20
25
R
S
max (
Ω
)
500
120
80
60
50
40
40
C
0
max (pF)
7
7
7
7
7
7
7
Note 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 23-4.
When designing the board, place the crystal resonator and its load capacitors as close as possible
to the XTAL and EXTAL pins.
C
L2
Signal A Signal B
C
L1
H8S/2633 Series
XTAL
EXTAL
Avoid
Figure 23-4 Example of Incorrect Board Design