Table of Contents
Advertisement
4.2 System Clock Generator
Clock pulses can be supplied to the system clock divider either by connecting a crystal or ceramic
oscillator, or by providing external clock input.
1. Connecting a crystal oscillator
Figure 4-2 shows a typical method of connecting a crystal oscillator.
OSC
1
R
OSC
2
Figure 4-3 shows the equivalent circuit of a crystal oscillator. An oscillator having the
characteristics given in table 4-1 should be used.
OSC
1
Table 4-1 Crystal Oscillator Parameters
Frequency (MHz)
R
max (Ω)
S
C
(pF)
0
R = 1 M
C
f
1
f
Frequency
1.0 MHz
C
2
4.0 MHz
Figure 4-2 Typical Connection to Crystal Oscillator
L
S
Figure 4-3 Equivalent Circuit of Crystal Oscillator
1
40
3.5 pF max
Ω
±20%
Crystal
oscillator
NDK
NDK
C
S
C
0
4.193
100
16 pF
88
C
, C
1
2
Recommendation
value
Products Name
27 pF ±10%
NR-18 (NDK45)
12 pF ±20%
NR-18 (NDK03)
R
S
OSC
2
Advertisement
Table of Contents
