Microelectromechanical device having an oscillating mass and a forcing stage, and method of controlling a microelectromechanical device

1. A method of controlling a microelectromechanical device, comprising:

oscillating a movable mass with respect to a body according to a degree of freedom, the movable mass being elastically coupled to the body;

detecting a current oscillation frequency of the movable mass using a frequency detector; and

providing energy to the movable mass by a forcing stage capacitively coupled to the movable mass, the energy being provided through forcing signals having a forcing frequency equal to the current oscillation frequency detected by the frequency detector in a start-up procedure of the microelectromechanical device.

2. The method of claim 1 further comprising detecting a current oscillation phase of the movable mass, wherein providing energy comprises providing the forcing signals with a constant phase delay with respect to the detected current oscillation phase.

3. The method of claim 2 , wherein the constant phase delay is less than π/2.

4. The method of claim 3 , wherein the constant phase delay is zero.

5. The method according to claim 1 further comprising maintaining the movable mass in oscillation at a driving frequency in a steady operating condition using a driving device coupled to the movable mass so as to form a microelectromechanical loop.

6. The method of claim 5 , wherein detecting the current oscillation frequency of the movable mass comprises providing a main clock signal synchronous with oscillations of the microelectromechanical loop in the start-up procedure, and the forcing signals are generated on the basis of the main clock signal in the start-up procedure.

7. The method of claim 1 , wherein detecting the current oscillation frequency of the movable mass comprises using a PLL circuit.

8. The method of claim 1 further comprising providing a reference clock signal, independent of oscillations of the movable mass; wherein providing energy to the movable mass through forcing signals comprises generating the forcing signals on the basis of the reference clock signal in a transient operating condition.

9. The method of claim 8 , wherein the forcing signals include a maximum number of cycles in the transient operating condition, the maximum number of cycles selected so that a phase delay of the forcing signals with respect to oscillations of the movable mass does not exceed π/2.

10. The method of claim 1 further comprising terminating supply of the forcing signals based on a comparison between a current oscillation amplitude of the movable mass and a threshold oscillation amplitude.

11. The method of claim 1 , wherein the forcing signals comprise sequences of square-wave pulses.

12. A method of controlling a microelectromechanical device, comprising:

oscillating a movable mass with respect to a body according to a degree of freedom;

detecting a current oscillation frequency of the movable mass; and

providing energy to the movable mass through forcing signals having a forcing frequency equal to the detected current oscillation frequency in a first transient operating condition; and

wherein detecting a current oscillation frequency of the movable mass includes,

providing a main clock signal synchronous with oscillations of the microelectromechanical loop in the first transient operating condition; and

generating the forcing signals on the basis of the main clock signal in the first transient operating condition.

13. The method of claim 12 , comprising detecting a current oscillation phase of the movable mass, wherein providing energy comprises providing the forcing signals with a constant phase delay with respect to the detected current oscillation phase.

14. The method of claim 13 , wherein the constant phase delay is less than π/2.

15. The method of claim 14 , wherein the constant phase delay is zero.

16. The method of claim 12 , comprising maintaining the microelectromechanical loop in oscillation at a driving frequency in a steady operating condition using a driving device coupled to the movable mass so as to form a microelectromechanical loop.

17. The method of claim 12 further comprising locking the forcing signals and oscillations of the microelectromechanical loop in the first transient operating condition.

18. A method of controlling a microelectromechanical device, comprising:

oscillating a movable mass with respect to a body according to a degree of freedom;

detecting a current oscillation frequency of the movable mass;

providing energy to the movable mass through forcing signals having a forcing frequency equal to the detected current oscillation frequency in a first transient operating condition;

providing a reference clock signal independent of oscillations of the movable mass; and

generating the forcing signals on the basis of the reference clock signal in a second transient operating condition.

19. The method of claim 1 , wherein the forcing signals include a maximum number of cycles in the second transient operating condition, the maximum number of cycles selected so that a phase delay of the forcing signals with respect to oscillations of the movable mass does not exceed π/2.