s-35199a01 Seiko Instruments Inc., s-35199a01 Datasheet - Page 44

• Manufacturer Part Number: s-35199a01
• Description: 3-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

44
3-WIRE REAL-TIME CLOCK
S-35199A01
Crystal oscillator: 32.768 kHz
Caution
Adjustment of Oscillation Frequency
1. Configuration of oscillation
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 the crystal oscillator with a C
C
C
C
Place the S-35199A01, 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-35199A01.
Locate the GND layer in the layer
immediately below
L
g
pi
, C
= 6 pF
= 0 to 9.1 pF
2. Oscillation characteristics is subject to the variation of each component such as substrate parasitic
1. When using the crystal oscillator with a C
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 54 Connection Diagram 1
Figure 55 Connection Diagram 2
pi
L
Seiko Instruments Inc.
po
value of 7 pF, externally connect C
XIN
XOUT
L
C
exceeding the rated value (7 pF) (e.g : C
d
C
g
g
VSS
D1
XIN
XOUT
) as close to each other as possible.
S-35199A01
R
R
Top View
f
d
C2
D2
A2
B2
g
. When configurating oscillator, pay
d
if necessary.
Make all the wiring reverse
from the crystal oscillator
VDD
A3
B3
D3
Oscillation internal constant
standard values:
S-35199A01
L
value of 6 pF or 7 pF.
R
R
C
f
d
d
= 100 MΩ
= 100 kΩ
= 8 pF
Surface wiring
Rear surface
Rev.1.0
L
wiring
= 12.5 pF),
_00