Microelectromechanical-based oscillators having adjustable gain amplifiers therein that support Q-factor control

A microelectromechanical-based oscillator circuit, comprising:

• a microelectromechanical resonator having first and second terminals;
• a variable impedance circuit having a first terminal electrically coupled to the first terminal of said microelectromechanical resonator;
• an adjustable gain amplifier electrically coupled to said variable impedance circuit;
• and
• a Q-factor control circuit electrically coupled to said variable impedance circuit and said adjustable gain amplifier, said Q-factor control circuit configured to drive said variable impedance circuit and said adjustable gain amplifier with first and second control signals, respectively, that cause a gain of said adjustable gain amplifier to be relatively high during a start-up time interval and relatively low during a post start-up time interval.

A microelectromechanical-based oscillator circuit, comprising:

• a microelectromechanical resonator, a variable impedance device and an adjustable gain amplifier configured in a loop so that the adjustable gain amplifier provides a feedback signal to said microelectromechanical resonator;
• and
• a Q-factor control circuit configured to:
• drive the adjustable gain amplifier with a first control signal that causes a gain of said adjustable gain amplifier to be relatively high during a start-up time interval when a Q-factor of the oscillator circuit is relatively low and relatively low during a post start-up time interval when the Q-factor of the oscillator circuit is relatively high;
• and
• drive the variable impedance device with a second control signal that causes an impedance of the variable impedance circuit to be relatively high (low) during the start-up time interval and relatively low (high) during the post start-up time interval, which follows the start-up time interval.