Datasheet

Section 5 Clock Pulse Generators
Rev. 1.50 Sep. 18, 2007 Page 86 of 584
REJ09B0240-0150
5.6 Subclock Generator
Figure 5.14 shows a block diagram of the subclock generator.
Note: Resistance is a reference value.
2
1
X
8 MΩ
X
Figure 5.14 Block Diagram of Subclock Generator
5.6.1 Connecting 32.768-kHz Crystal Resonator
Clock pulses can be supplied to the subclock divider by connecting a 32.768-kHz crystal
resonator, as shown in figure 5.15. Figure 5.16 shows the equivalent circuit of the 32.768-kHz
crystal resonator.
Capacitances are reference values.
C
1
C
2
X1
X2
C
1
= C
2
= 15 pF (typ.)
Figure 5.15 Typical Connection to 32.768-kHz Crystal Resonator
C
O
= 1.5 pF (typ.)
R
S
= 14 kΩ (typ.)
fW = 32.768 kHz
Note: Parameters are reference values.
C
S
C
O
R
S
L
S
X1 X2
Figure 5.16 Equivalent Circuit of 32.768-kHz Crystal Resonator