80
Connecting a Crystal Oscillator: Figure 4.2 shows a typical method of connecting a crystal
oscillator.
1
2
C
1
C
2
OSC
OSC
R = 1 M
±
20%
C = C = 12 pF
±
20%
f
1
2
Ω
R
f
Figure 4.2 Typical Connection to Crystal Oscillator
Figure 4.3 shows the equivalent circuit of a crystal oscillator. An oscillator having the
characteristics given in table 4.1 should be used.
C
S
C
0
R
S
OSC
1
OSC
2
L
S
Figure 4.3 Equivalent Circuit of Crystal Oscillator
Table 4.1
Crystal Oscillator Parameters
Frequency
2 MHz
4 MHz
8 MHz
10 MHz
R
S
(max)
500
Ω
100
Ω
50
Ω
30
Ω
C
0
(max)
7 pF
7 pF
7 pF
7 pF