Capacitive MEMS sensor device

An electronic circuit for a capacitive Micro Electro Mechanical System (MEMS) sensor device that senses a mechanical quantity, the capacitive MEMS sensor device comprising a capacitive MEMS sensing element having two plates arranged in parallel at a distance that varies in response to said mechanical quantity and converting the sensed mechanical quantity into an electrical quantity, the electronic circuit comprising:

• a first bias voltage unit that supplies a first bias voltage to a first plate of said capacitive MEMS sensing element;
• a second bias voltage unit that supplies a second bias voltage to a second plate of said capacitive MEMS sensing element;
• a signal processing unit that processes said electrical quantity into an output signal;
• a comparator unit that compares said output signal to a reference signal to detect an overload condition of said capacitive MEMS sensing element and outputs a comparator signal;
• and
• a control unit that controls the discharge of said capacitive MEMS sensing element based upon said comparator signal by connecting, after detection of the overload condition, said first plate to a discharge terminal during a first time interval and said second plate to the discharge terminal during a second time interval, wherein the first bias voltage and the second bias voltage are separately controlled.

A method of operating a capacitive Micro Electro Mechanical System (MEMS) sensor device that senses a mechanical quantity, the capacitive MEMS sensor comprising a capacitive MEMS sensing element having two plates arranged in parallel at a distance that varies in response to said mechanical quantity and converting the sensed mechanical quantity into an electrical quantity, the method comprising:

• supplying a first bias voltage to a first plate of said capacitive MEMS sensing element;
• supplying a second bias voltage to the second plate of said capacitive MEMS sensing element;
• processing said electrical quantity into an output signal;
• comparing said output signal to a reference signal to detect an overload condition of said capacitive MEMS sensing element;
• outputting a comparator signal based upon the comparison;
• and
• controlling the discharge of said capacitive MEMS sensing element based upon said comparator signal by connecting, after detection of the overload condition, said first plate to a discharge terminal during a first time interval and said second plate to the discharge terminal during a second time interval, wherein the first bias voltage and the second bias voltage are separately controlled.