Proposed Manufacturing Approach for Achieving Fast Startup of Crystal Oscillators

Crystal oscillators provide reliable, accurate, and stable reference signals. As such, they play the vital role of a clock for most integrated circuits. However, because the device’s initial startup condition is microscopic noise voltage, the time required to achieve the necessary clock signal is relatively long. Numerous proposals for reducing this latency by redesigning the device’s active circuit have been presented. In this article, a manufacturing approach is given that entails re-engineering the fundamental parameters of the crystal, i.e., the bandwidth and motional arm parameters modeled as an RLC circuit. Recent advances in manufacturing techniques, e.g., additive manufacturing and materials science, were the impetus for the approach. A model is developed that starts with an oscillator that is currently in commercial production and extrapolates to one having a much-improved startup time. In addition to timing, the model addresses the issues of maintaining the frequency variation of the signal and power dissipation of the oscillator within acceptable limits. Modeling predictions show how the startup time of a 32.768 kHz clock can be improved by a factor of 10. In addition, it is shown how to construct a device with a startup time of less than 5 μs.