S-35390A Seiko Instruments, S-35390A Datasheet - Page 33

• Manufacturer Part Number: S-35390A
• Description: 2-Wire Real Time Clock
• Manufacturer: Seiko Instruments

Rev.1.2
1. Configuration of oscillator
Adjustment of Oscillation Frequency
Since crystal oscillation is sensitive to external noise (the clock accuracy is affected), the following
measures are essential for optimizing the oscillator configuration.
(1) Place the S-35390A, crystal oscillator, and external capacitor (C
(2) Increase the insulation resistance between pins and the substrate wiring patterns of XIN and
(3) Do not place any signal or power lines close to the oscillator.
_00
Crystal oscillator: 32,768 Hz
*1. When using the crystal oscillator with a C
possible.
XOUT.
Parasitic capacitance C
C
C
C
L
g
po
= 6 pF
= 0 to 9.1 pF
Parasitic
capacitance C
< 5 pF
C
g
*1
pi
oscillator
Crystal
XOUT
po
XIN
Figure 36 Connection Diagram 1
Figure 37 Connection Diagram 2
C
Seiko Instruments Inc.
g
C
d
L
value of 7 pF, externally connect C
1
2
3
4
R
R
d
f
XOUT
XIN
VSS
S-35390A
Oscillator internal constant
standard values:
R
R
C
2-WIRE REAL-TIME CLOCK
f
d
d
= 100 MΩ
= 100 kΩ
= 8 pF
8
7
6
5
d
g
.
) as close to each other as
S-35390A
S-35390A
33