Abstract
Due to the rapid growth of electronic information technology, the need for the higher stability of crystal oscillators has increased. The temperature-compensated X’tal (crystal) oscillator (TCXO), a type of crystal oscillator with high frequency stability, has been widely used in communications, sensor networks, automotive electronics, industrial control, measuring devices, and other equipment. The traditional TCXO only performs frequency compensation based on the current temperature, without considering the error caused by thermal hysteresis. As the frequency stability of the TCXO improves, the thermal hysteresis of the crystal oscillator has a negligible influence on the frequency stability of the crystal oscillator. This study measured different compensation tables for hysteresis curves at different temperatures and used a microprocessor to store the historical information of crystal temperature changes. Furthermore, corresponding algorithms were designed to select the correct values, according to the temperature change history, to compensate for the thermal hysteresis of the crystal oscillator error. Experiments show that this method can reduce the hysteresis error of the crystal oscillator from 700 to 150 ppb (−40 to 80 °C).
Highlights
Clock signals are critical in numerous electronic systems, wireless sensor networks and wireless Internet of Things devices that contain multiple sensors [1,2,3,4]
The authors in [25] show that, through strict process control, the hysteresis error of the SC-cut crystal oscillator can be reduced to several ppb, which can further improve the frequency stability of the temperature-compensated X’tal (crystal) oscillator (TCXO)
This jitter is the frequency instability mentioned in the TCXO that occurs when the effect of thermal hysteresis is not taken into consideration
Summary
Clock signals are critical in numerous electronic systems, wireless sensor networks and wireless Internet of Things devices that contain multiple sensors [1,2,3,4]. Because of the use of low-temperature vacuum packaging technology, a hysteresis error of −17 to 70 ◦ C was reduced to 66 ppb, which in turn increased the stability of the TCXO to ±190 ppb. The authors in [25] show that, through strict process control, the hysteresis error of the SC-cut crystal oscillator can be reduced to several ppb, which can further improve the frequency stability of the TCXO. The use of a cheaper AT-cut crystal to achieve higher frequency stability while reducing hysteresis error would be highly significant. A specially designed TCXO is implemented that reduces the compensated hysteresis error of −40 to 80 ◦ C from about 700 ppb to about 150 ppb
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
