RV-3029 Datasheet, PDF (41/67 Pages) MICORO CRYSTAL SWITZERLAND – DTCXO Temperature Compensated Real Time Clock

Micro Crystal
DTCXO Temperature Compensated Real Time Clock / Calendar Module
RV-3029
5.3. METHOD OF COMPENSATING THE FREQUENCY DEVIATION
The Frequency Compensation Unit (FCU) calculates every 32 seconds the compensation factor needed to obtain
accurate time information. The compensation is made by adding or subtracting correction clocks to the 32.768 kHz
reference frequency at the first stage of the frequency divider chain, thereby changing the period of a single
second.
Extra clocks are added for to speed-up the timing, subtracting clocks to slow-down the timing.
If 32.768 kHz Clock too fast: then 32.768kHz clocks are suppressed to obtain a compensated and
accurate RTC timing.
If 32.768 kHz Clock too slow: then extra correction clocks are added to obtain a compensated and
accurate RTC time.
Each compensation period takes 32 seconds. Correction clocks are periodically applied during one complete
compensation period. Within a compensation period of 32 seconds, one correction clock will compensate the time
information by ±1 ppm.
Time compensation cycle 32 seconds: within a time compensation cycle of 32 seconds, the required
numbers of 32.768kHz clocks are periodically suppressed (or added) to compensate the anticipated
deviation of 32.768kHz reference clock.
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