s-35399a02 Seiko Instruments Inc., s-35399a02 Datasheet - Page 46

• Manufacturer Part Number: s-35399a02
• Description: 2-wire Real-time Clock
• Manufacturer: Seiko Instruments Inc.

46
2-WIRE REAL-TIME CLOCK
S-35399A02
2. Measurement of oscillation frequency
When the S-35399A02 is turned on, the internal power-on detector operates and a signal of 1 Hz is output from the
pin to select the crystal oscillator and optimize the C
counter following the circuit configuration shown in Figure 62 .
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” .
Caution
Remark If the error range is ± 1 ppm in relation to 1 Hz, the time is shifted by approximately 2.6 seconds per month
1 kΩ
Open
Open
Open
Open
or pull-up
(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 use operation conditions.
3. Since the 1 Hz signal continues to be output, initialization must be executed during normal
–6
(1 ppm) × 60 seconds × 60 minutes × 24 hours × 30 days = 2.592 seconds
operation.
1 kΩ
Figure 62 Configuration of Oscillation Frequency Measurement Circuit
SDA
SCL
CTRL
F32K
FOUT
INT2
S-35399A02
Seiko Instruments Inc.
g
VDDL
value. Turn the power on and measure the signal with a frequency
XOUT
INT1
VDD
VSS
XIN
C
g
10 kΩ
Frequency
counter
Rev.1.0
_00
INT
1