Subclock Generator - Hitachi HD6473867 Hardware Manual

4.3 Subclock Generator

1. Connecting a 32.768-kHz/38.4 kHz crystal oscillator
Clock pulses can be supplied to the subclock divider by connecting a 32.768-kHz/38.4 kHz crystal
oscillator, as shown in figure 4-7. Follow the same precautions as noted under 3. notes on board
design for the system clock in 4.2.
X
1
X
2
Figure 4-7 Typical Connection to 32.768-kHz/38.4 kHz Crystal Oscillator (Subclock)
Figure 4-8 shows the equivalent circuit of the 32.768-kHz/38.4 kHz crystal oscillator.
X
1
Figure 4-8 Equivalent Circuit of 32.768-kHz/38.4 kHz Crystal Oscillator
C
1
C = C
Frequency
32.768 kHz
C
2
38.4 kHz
C
S
L
S
C
0
= 15 pF (typ.)
1 2
Crystal oscillator
NDK
Seiko Instrument Inc.
R
S
C = 1.5 pF typ
0
Ω
R = 14 k typ
S
f = 32.768 kHz/38.4kHz
W
91
Products Name
MX73P
VTC-200
X
2