s-35392a Seiko Instruments Inc., s-35392a Datasheet - Page 38

• Manufacturer Part Number: s-35392a
• Description: 2-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

38
2-WIRE REAL-TIME CLOCK
S-35392A
2. Measurement of oscillation frequency
When the S-35392A is turned on, a signal of 32.768 kHz is output from the 32KO pin. Turn the power on and measure the
signal with a frequency counter following the circuit configuration shown in Figure 47.
Caution
Remark If the error range is ± 1 ppm in relation to 32.768 kHz, the time is shifted by approximately 2.6 seconds per
Open
or pull-up
1 kΩ
month (calculated using the following expression).
10
1. Use a high-accuracy frequency counter of 7 digits or more.
2. Measure the oscillation frequency under the usage conditions.
–6
(1 ppm) × 60 seconds × 60 minutes × 24 hours × 30 days = 2.592 seconds
1 kΩ
Figure 47 Configuration of Oscillation Frequency Measurement Circuit
SDA
SCL
INT2
S-35392A
Seiko Instruments Inc.
XOUT
32KO
VDD
VSS
XIN
C
g
10 kΩ
Frequency
counter
Rev.1.3
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