HD6475328-CP10 Datasheet, PDF (153/459 Pages) Hitachi Semiconductor – original Hitachi CMOS microcomputer unit (MCU)

EXTAL
XTAL
CL1
CL2
CL1 =CL2 =10 to 22pF
Figure 8-2 Connection of Crystal Oscillator (Example)
(2) Crystal Oscillator: The external crystal should have the characteristics listed in table 8-1.
XTAL
CL
L
RS
EXTAL
C0
AT-cut parallel resonating crystal
Figure 8-3 Crystal Oscillator Equivalent Circuit
Table 8-1 External Crystal Parameters
Frequency (MHz) 2
4
8
12
16
20
Rs max (Ω)
500 120 60
40
30
20
C0 (pF)
7pF max
(3) Note on Board Design: When an external crystal is connected, other signal lines should be
kept away from the crystal circuit to prevent induction from interfering with correct
oscillation. See figure 8-4.
When the board is designed, the crystal and its load capacitors should be placed as close as
possible to the XTAL and EXTAL pins.
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