Fast & Energy Efficient Start-Up of Crystal Oscillators by Self-Timed Energy Injection

• Published in: IEEE journal of solid-state circuits Vol. 54; no. 11; pp. 3107 - 3117
• Main Authors: Lechevallier, Joeri B., Van Der Zee, Ronan A. R., Nauta, Bram
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-11-2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitance; Crystal oscillators; Crystals; Current measurement; duty cycling; Energy consumption; energy injection; Internet of Things; Internet of Things (IoT); low power; Oscillators; Power consumption; Resistance; start-up energy; start-up time
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2019.2933143

Crystal oscillators take a long time and, more importantly, a significant amount of energy to start-up. This article presents a self-timed energy injection technique to quickly start-up a crystal oscillator, for very low energy consumption. This is achieved without a power-hungry oscillator to provide the injection signal. The design considerations are discussed, and a prototype crystal oscillator using the proposed technique is integrated into a 22-nm fully depleted silicon-on-insulator (FD-SOI) technology. Connected to a 50-MHz crystal, the manufactured IC achieves a start-up time of 6 μs, for an energy consumption of just 3.7 nJ.