
HD404344R Series/HD404394 Series
40
Table 16
Oscillator Circuit Examples
Circuit Configuration
Circuit Constants
External clock operation
External
oscillator
OSC
Open
1
OSC
2
Ceramic oscillator
(OSC
1
, OSC
2
)
OSC
2
C
1
2
C
OSC
1
R
f
Ceramic
oscillator
GND
Ceramic oscillator : CSA4.00MG (Murata)
R
f
= 1 M
±
20%
C
1
= C
2
= 30 pF
±
20%
Ceramic oscillator: KBR-4.0MSA (Kyocera)
R
f
= 1 M
±
20%
C
1
= C
2
= 33 pF
±
20%
CR oscillation
(OSC
, OSC
)
HD404344R series
OSC
2
OSC
1
R
f
R
f
= 20 k
±
1%
Notes: 1. Since the circuit constants change depending on the ceramic oscillator and stray capacitance of
the board, the user should consult with the ceramic oscillator manufacturer to determine the
circuit parameters.
2. Wiring among OSC
, OSC
2
, and elements should be as short as possible, and must not cross
other wiring (see figure 18).