S-35199A01 Datasheet, PDF (45/54 Pages) Seiko Instruments Inc – 3-WIRE REAL-TIME CLOCK

Rev.1.0_00
3-WIRE REAL-TIME CLOCK
S-35199A01
2. Measurement of oscillation frequency
When the S-35199A01 is turned on, the internal power-on detector operates and a signal of 1 Hz is output from the INT
pin to select the crystal oscillator and optimize the C_g value. Turn the power on and measure the signal with a frequency
counter following the circuit configuration shown in Figure 56.
If 1 Hz signal is not output, the power-on detector does not operate normally. Turn off the power and then turn it on
again. For how to apply power, refer to “„ Power-on Detector and Register Status”.
Remark If the error range is ±1 ppm in relation to 1 Hz, 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
10 kΩ 10 kΩ
Open
Open
Open
Open
VDD
VDDL
SIO
SCK
CTRL
F32K
FOUT
CS
S-35199A01
XIN
XOUT
INT
VSS
Cg 10 kΩ
Frequency
counter
Figure 56 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 condition.
3. Since the 1 Hz signal continues to be output, initialization must be executed during normal
operation.
Seiko Instruments Inc.
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