S-35392A Datasheet, PDF (38/47 Pages) Seiko Instruments Inc – 2-WIRE REAL-TIME CLOCK

2-WIRE REAL-TIME CLOCK
S-35392A
Rev.1.3_00
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.
Remark If the error range is ±1 ppm in relation to 32.768 kHz, the time is shifted by approximately 2.6 seconds per
month (calculated using the following expression).
10^–6 (1 ppm) × 60 seconds × 60 minutes × 24 hours × 30 days = 2.592 seconds
1 kΩ
1 kΩ
SDA
SCL
Open
or pull-up
INT2
VDD
XIN
S-35392A
XOUT
32KO
VSS
Cg 10 kΩ
Frequency
counter
Figure 47 Configuration of Oscillation Frequency Measurement Circuit
Caution 1. Use a high-accuracy frequency counter of 7 digits or more.
2. Measure the oscillation frequency under the usage conditions.
38
Seiko Instruments Inc.