HD6413003RF Datasheet, PDF (524/715 Pages) Renesas Technology Corp – Microcontroller (MCU)

16.2 Oscillator Circuit
Clock pulses can be supplied by connecting a crystal resonator, or by input of an external clock
signal.
16.2.1 Connecting a Crystal Resonator
Circuit Configuration: A crystal resonator can be connected as in the example in figure 16-2.
The damping resistance Rd should be selected according to table 16-1. An AT-cut parallel-
resonance crystal should be used.
C _L1
EXTAL
XTAL
C _L2
C_L1 = C _L2 = 10 pF to 22 pF
Figure 16-2 Connection of Crystal Resonator (Example)
Table 16-1 Damping Resistance Value
Frequency (MHz)
Rd (Ω)
2
4
8
10
12
16
20
24
1k
500
200
70
0
0
0
0
Crystal Resonator: Figure 16-3 shows an equivalent circuit of the crystal resonator. The crystal
resonator should have the characteristics listed in table 16-2.
XTAL
C_L
L
Rs
EXTAL
C_O
AT-cut parallel-resonance type
Figure 16-3 Crystal Resonator Equivalent Circuit
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