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

Abstract

The watch crystal oscillator can achieve very-lowpower time-keeping, even less than 1μW, 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.I.