Microelectromechanical gyroscope with calibrated synchronization of actuation and method for actuating a microelectromechanical gyroscope

A system, comprising:

• a control unit;
• and
• a microelectromechanical gyroscope coupled to the control unit and including:
• a body;
• a driving mass movable with respect to the body with a first degree of freedom according to a driving axis;
• a sensing mass mechanically coupled to the driving mass so as to be drawn in motion according to the driving axis and movable with respect to the driving mass with a second degree of freedom according to a sensing axis, in response to rotations of the body;
• a driving device, forming a microelectromechanical control loop with the body and the driving mass and configured to maintain the driving mass in oscillation according to the driving axis with a driving frequency, the driving device including:
• a frequency detector coupled to a control node of the microelectromechanical control loop and configured to provide a first clock signal with a frequency substantially equal to a current oscillation frequency of the driving mass;
• a synchronization stage coupled to the frequency detector and configured to apply, in a first operation mode, a calibrated phase shift to the first clock signal to compensate for a phase shift arising between the driving mass and the control node, wherein:
• the synchronization stage is configured to provide a second clock signal that, in the first operation mode, has the same frequency as the first clock signal and a phase shift equal to the calibrated phase shift;
• the driving device includes a timing generator coupled to the synchronization stage and configured to provide a plurality of timing signals based on the second clock signal;
• and
• the driving device includes an oscillator configured to provide to the synchronization stage a third clock signal having an auxiliary frequency close to the driving frequency.

A method for actuating a microelectromechanical gyroscope that includes a body, a driving mass movable with respect to the body with a first degree of freedom according to a driving axis, and a sensing mass mechanically coupled to the driving mass so as to be drawn in motion according to the driving axis and movable with respect to the driving mass with a second degree of freedom according to a sensing axis, in response to rotations of the body, the method comprising:

• maintaining the driving mass in oscillation according to the driving axis with a driving frequency through a microelectromechanical control loop including the body and the driving mass;
• detecting a current oscillation frequency of the driving mass at a control node of the microelectromechanical control loop;
• applying, in a first operation mode, to a first clock signal a calibrated phase shift calibrated to compensate for a phase shift caused by components of the microelectromechanical control loop arranged between the driving mass and the control node;
• producing a second clock signal that, in the first operation mode, has the same frequency as the first clock signal and a phase shift equal to the calibrated phase shift;
• producing a third clock signal having a frequency close to the driving frequency;
• comparing the frequency of the first clock signal with the frequency of the third clock signal;
• providing, in a second operation mode, the second clock signal with a frequency equal to the frequency of the third clock signal;
• switching from the first operation mode to the second operation mode when a difference between the frequency of the first clock signal and the frequency of the third clock signal exceeds a threshold stage;
• and
• switching from the second operation mode to the first operation mode when the difference between the frequency of the first clock signal and the auxiliary frequency of the third clock signal falls below the threshold.