Patent ID: 8487709

Claim:
An oscillator circuit comprising: a piezoelectric vibrator; an amplifier device connected to the piezoelectric vibrator and configured to amplify an oscillation output from the piezoelectric vibrator, the amplifier device including inverters connected in series to each other; and an inverter control device configured to control an operational state of the inverters, wherein: the inverters includes: a performance-variable inverter which is operational in both of an initial phase of oscillation startup and a post-startup phase where oscillation is stabilized and is configured to carry out a variable performance depending on whether the oscillator circuit is in the initial phase of oscillation startup or the post-startup phase; and an ON/OFF inverter which is operational in the initial phase of oscillation startup and disconnected in the post-startup phase, and the inverter control device includes: an amplitude detection circuit configured to detect an amplitude of a signal in any arbitrary section of the amplifier device; and a control signal output circuit configured to generate and output a control signal which triggers operational state switchover of the inverters when the amplitude detected by the amplitude detection unit equals to a given threshold value.