Low frequency quartz oscillator device with improved thermal characteristics
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jan 21, 2003
Grant Date -
Jun 21, 2001
app pub date -
Dec 11, 2000
filing date -
Dec 21, 1999
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
The present invention concerns a low frequency oscillator device including a quartz resonator (1) and an electronic maintenance circuit for maintaining the vibrations of said quartz resonator. According to the present invention, the quartz resonator is arranged to vibrate according to a torsional mode and therefore has a single cutting angle defined by a rotation at a determined angle (.theta.) about the crystallographic axis X of the quartz crystal. This resonator includes in particular at least one undesired fundamental flexural vibrating mode at a first frequency and a desired fundamental torsional vibrating mode at a second frequency higher than said first frequency. Moreover, the electronic maintenance circuit is an inverter circuit (2) whose transconductance value (g.sub.m) is determined such that said device cannot oscillate according to the undesired fundamental flexural vibrating mode but according to the desired fundamental torsional vibrating mode of said resonator. The oscillator device according to the present invention thus has substantially improved thermal characteristics with respect to known oscillator devices using flexural vibrating resonators.
First Claim
Other Claims data not available
