A Quick Start-Up Crystal Oscillator with Negative Resistance Boosting Technique and Automatic Amplitude Control

This paper presents a duty-cycled operation fast start-up crystal oscillator for Internet of Things (IoT) wireless communication system. Using Negative Resistance Boosting (NRB) method, the proposed crystal oscillator overcomes the conventional Pierce crystal oscillator’s long start-up time issue (which is in milliseconds range). The crystal oscillator is implemented in a 65-nm CMOS technology, achieving a fast start-up time around 502μs at 40-Mhz with 3.3 V supply voltage. An Automatic Amplitude Control (AAC) feedback method keeps monitoring of the output swing of the oscillator and decides boosting/steady mode of the oscillator. By implementing NRB and AAC techniques, the overall energy consumption is reduced effectively.