S-35192A-I8T1G SII [Seiko Instruments Inc], S-35192A-I8T1G Datasheet - Page 31

• Manufacturer Part Number: S-35192A-I8T1G
• Description: 3-WIRE REAL-TIME CLOCK
• Manufacturer: SII [Seiko Instruments Inc]

Rev.1.2
Caution
Adjustment of Oscillation Frequency
1. Configuration of oscillation
Crystal oscillator: 32.768 kHz
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 setting the value for the crystal oscillator’s C
*2. Design the board so that the parasitic capacitance is 5 pF.
*3. The oscillator operates unless C
advances.
Place the S-35192A, 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-35192A.
_00
C
C
1. When using the crystal oscillator with a C
2. Oscillation characteristics are subject to the variation of each component such as substrate parasitic
L
g
= 6 pF
= None
oscillation operation may become unstable. Use a crystal oscillator with a C
capacitance, parasitic resistance, crystal oscillator, and C
sufficient attention for them.
*1
*2
to 9.1 pF
Parasitic capacitance
Crystal oscillator
C
g
Parasitic
capacitance
g
Figure 35 Connection Diagram 1
Figure 36 Connection Diagram 2
is not connected. Note that the oscillation frequency is in the direction that
*3
Seiko Instruments Inc.
C
*3
g
L
as 7 pF, connect C
XIN
XOUT
L
1
2
3
4
Locate the GND layer in the
layer immediately below
exceeding the rated value (7 pF) (e.g : C
C
XIN
VSS
XOUT
d
S-35192A
g
) as close to each other as possible.
d
R
R
externally if necessary.
f
d
3-WIRE REAL-TIME CLOCK
g
. When configuring oscillator, pay
8
7
6
5
Oscillation internal constant
standard values:
L
S-35192A
value of 6 pF or 7 pF.
R
R
C
f
d
d
= 100 MΩ
= 100 kΩ
= 8 pF
S-35192A
L
= 12.5 pF),
31