Patent ID: 6509804
Filing Date: 2003-01-21
Classification: H03B,H03H,H03K

Abstract:
A low frequency oscillator device including a quartz resonator and an electronic maintenance circuit for maintaining the vibrations of said quartz resonator, wherein:said quartz resonator has a single cutting angle defined by a rotation at a determined angle about the crystallographic axis X of said quartz, so that said resonator includes at least one fundamental flexural vibrating mode at a first frequency and a fundamental torsional vibrating mode at a second frequency higher than said first frequency; and said electronic maintenance circuit for maintaining the vibrations of the resonator is an inverting amplifier circuit whose transconductance value is determined such that said device cannot oscillate according to said fundamental flexural vibrating mode but according to said fundamental torsional vibrating mode of said resonator said inverting amplifier circuit including an input at which is connected a first load capacitor and an output at which is connected a second load capacitor, said quartz resonator being connected in the feedback path of said inverting amplifier, said electronic maintenance circuit also including a feedback resistor connected across the input and the output of said inverting amplifier, the value of said feedback resistor being determined so as to substantially reduce the maximum transconductance value relative to the fundamental flexural vibrating mode of the resonator.