S-35399A02 Datasheet, PDF (30/55 Pages) Seiko Instruments Inc – 2-WIRE REAL-TIME CLOCK

2-WIRE REAL-TIME CLOCK
S-35399A02
Rev.1.0_00
6. Operation of power-on detection circuit (only in the INT1 pin output mode)
When power is applied to the S-35399A02, the power-on detection operates to set “1” in the POC flag (B0 in the status
register 1). A 1 Hz clock pulse is output from the INT1 pin.
Status register 2 setting
• 32kE = 0, INT1AE = INT1ME = 0
Change by reset command
INT1FE
OFF
INT1 pin
0.5 s ^{0.5 s}
Figure 36 Output Timing of INT1 Pin during Operation of Power-on Detection Circuit
„ Function to Clock-Correction
The function to clock-correction is to correct advance/delay of the clock due to the deviation of oscillation frequency, in
order to make a high precise clock. For correction, the S-35399A02 adjusts the clock pulse by using a certain part of the
dividing circuit, not adjusting the frequency of the crystal oscillator. Correction is performed once every 20 seconds (or 60
seconds). The minimum resolution is approx. 3 ppm (or approx. 1 ppm) and the S-35399A02 corrects in the range of
−195.3 to +192.2 ppm (or of −65.1 to +64.1 ppm). (Refer to Table 14.) Users can set up this function by using the
clock-correction register. Regarding how to calculate the setting data, refer to “1. How to calculate”. When not using this
function, be sure to set “00h”.
Correction
Minimum resolution
Correction range
Table 14 Function to Clock-Correction
B0 = 0
Every 20 seconds
3.052 ppm
−195.3 to +192.2 ppm
B0 = 1
Every 60 seconds
1.017 ppm
−65.1 to +64.1 ppm
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Seiko Instruments Inc.