A novel method for low-power, high-precision timekeeping based on MCXO

The watch crystal oscillator can achieve very-low-power time-keeping, even less than 1 muW, which best overall accuracy with temperature-compensation has remained at about 1 ppm. For comparison, the timing system using microprocessor compensated (AT or SC-cut) crystal oscillator is capable of providing at least 10- to 100-times improvement in time-keeping accuracy, milliseconds-per-day, with the penalty of requiring considerably more power, about tens of milliwatts. In this paper a novel method for time-keeping based on MCXO is described, which is to simultaneously meet the needs of very-low-power and high-precision timing.