Low power oscillator having fast start-up times

摘要

A low power oscillator having fast start-up times. The low power fast starting oscillator uses an oscillator circuit having an input and an output for generating a signal of a desired frequency. A start-up detect circuit is coupled to the output of the oscillator circuit for detecting when the oscillator circuit has reached steady state operation and for generating a start-up circuit output signal which adjusts the gain of the oscillator circuit when steady state operation has been reached by the oscillator circuit. A noise generator is coupled to the input of the oscillator circuit and to the start-up detect circuit for inputting a noise pulse into the oscillator circuit. The noise pulse is used for biasing the input of the oscillator circuit to approximately an optimal bias voltage level. The noise generator is further used for sending an enable start-up detect signal to the start-up detect circuit to activate the start-up detect circuit. A prestress circuit is coupled to the input and to the output of the oscillator circuit for prestressing a piezoelectric resonator of the oscillator circuit to shorten start-up times of the oscillator circuit. The prestress circuit is further used for sending an enable noise generator signal to the noise generator to activate the noise generator.