Semiconductor integrated circuit including circuit for driving electrostatic actuator, micro-electro-mechanical systems, and driving method of electrostatic actuator

A semiconductor integrated circuit comprising:

• an electrostatic actuator having a top electrode, a bottom electrode, and an insulating film disposed between the top electrode and the bottom electrode;
• an estimation circuit which monitors a pull-out voltage to separate the top electrode and the bottom electrode from each other;
• and
• a bias circuit which determines the direction of an electric field applied to the insulating film by the top electrode and the bottom electrode when the electrostatic actuator is driven, based on the pull-out voltage monitored by the estimation circuit, and which applies one of a positive voltage and a ground voltage to the top electrode, and the other to the bottom electrode.

A semiconductor integrated circuit comprising:

• an electrostatic actuator having a top electrode, a bottom electrode, and an insulating film disposed between the top electrode and the bottom electrode;
• an estimation circuit which estimates whether the amount of a charge accumulated in the insulating film of the electrostatic actuator is within a predetermined range;
• and
• a bias circuit which applies one of a positive voltage and a ground voltage to the top electrode, and the other to the bottom electrode to inject or pull out a charge into or from the insulating film so that the charge amount falls within the predetermined range, when it is estimated that the amount of the charge accumulated in the insulating film is not within the predetermined range.