Oscillator; Connecting A Crystal Resonator; Figure 19.2 Connection Of Crystal Resonator (Example); Figure 19.3 Crystal Resonator Equivalent Circuit - Renesas H8S Series Hardware Manual

Section 19 Clock Pulse Generator
19.2

Oscillator

Clock pulses can be supplied by connecting a crystal resonator, or by input of an external clock. In
either case, the input clock should not exceed 20 MHz.
19.2.1

Connecting a Crystal Resonator

Circuit Configuration: A crystal resonator can be connected as shown in the example in figure
19.2. Select the damping resistance R
crystal should be used.
EXTAL
XTAL

Figure 19.2 Connection of Crystal Resonator (Example)

Table 19.1 Damping Resistance Value

Frequency (MHz)
R (Ω)
d
Figure 19.3 shows the equivalent circuit of the crystal resonator. Use a crystal resonator that has
the characteristics shown in table 19.2.
XTAL
Rev. 6.00 Mar 15, 2006 page 484 of 570
REJ09B0211-0600
according to table 19.1. An AT-cut parallel-resonance
d
C
L1
R C
d L2
4 8
500 200
C
L
L
C
0

Figure 19.3 Crystal Resonator Equivalent Circuit

C = C = 10 to 22 pF
L1 L2
10 12
0 0
R
s
EXTAL
AT-cut parallel-resonance type
16 20
0 0