s-35399a02 Seiko Instruments Inc., s-35399a02 Datasheet - Page 45

• Manufacturer Part Number: s-35399a02
• Description: 2-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

Crystal oscillator: 32.768 kHz
Rev.1.0
Caution
Adjustment of Oscillation Frequency
1. Configuration of oscillator
Since crystal oscillation is sensitive to external noise (the clock accuracy is affected), the following measures are
essential for optimizing the oscillation configuration.
(1)
(2)
(3)
(4)
(5)
*1. When using a crystal oscillator with a C
C
C
C
Place the S-35399A02, crystal oscillator, and external capacitor (C
Increase the insulation resistance between pins and the substrate wiring patterns of XIN and XOUT.
Do not place any signal or power lines close to the oscillator.
Locating the GND layer immediately below the oscillator is recommended.
Locate the bypass capacitor adjacent to the power supply pin of the S-35399A02.
Locate the GND layer in the layer
immediately below
L
g
pi
_00
, C
= 6 pF
= 0 to 9.1 pF
1. When using the crystal oscillator with a C
2. Oscillation characteristics is subject to the variation of each component such as substrate parasitic
po
oscillation operation may become unstable. Use a crystal oscillator with a C
capacitance, parasitic resistance, crystal oscillator, and C
sufficient attention for them.
< 5 pF
*1
Parasitic capacitance C
Parasitic capacitance C
Crystal oscillator
C
g
Figure 60 Connection Diagram 1
Figure 61 Connection Diagram 2
pi
L
value of 7 pF, externally connect C
Seiko Instruments Inc.
po
L
XOUT
XIN
exceeding the rated value (7 pF) (e.g : C
C
C
g
d
g
VSS
D1
XIN
XOUT
) as close to each other as possible.
S-35399A02
Top View
g
R
R
C2
D2
A2
B2
. When configuring an oscillator, pay
d
2-WIRE REAL-TIME CLOCK
f
d
if necessary.
Make all the wiring reverse
from the crystal oscillator
VDD
A3
B3
D3
Oscillator internal constant
standard values:
L
value of 6 pF or 7 pF.
S-35399A02
S-35399A02
R
R
C
Surface wiring
Rear surface
f
d
d
= 100 MΩ
= 100 kΩ
= 8 pF
L
wiring
= 12.5 pF),
45