Temperature compensated crystal oscillator employing new shape GT cut quartz crystal resonator

The authors describe a temperature internally compensated crystal oscillator using the novel GT-cut quartz crystal resonator formed by an etching method. The object is to clarify if drain output resistance R_d and resistance R_qs connected in series to the resonator in elements constructing a CMOS oscillator circuit which suppress spurious vibrations, influence oscillation frequency and frequency-temperature behavior. First, a CMOS quartz crystal oscillator circuit is transformed into an equivalent circuit, and an equation which gives oscillation frequencies is derived from Kirchhoff´s law. Second, since the equation is given as a function of R_d and R_qs, it is theoretically predicted and experimentally shown that R_d and R _qs influence the oscillation frequency and the frequency-temperature behavior