Abstract: A circuit for a micromechanical structure-borne sound sensor and a method for operating this sensor, a voltage generator being used to apply voltages to at least one micromechanical element for recording the structure-borne sound, so that a change in the micromechanical element occurs. In addition, an evaluation circuit is provided, which records the at least one electrically recordable parameter of micromechanical element at a sampling rate and analyzes the same. This at least one parameter changes in response to the change. A clock-pulse generator is also provided for generating the sampling rate and for generating the clock pulse. A frequency generator is used for generating the clock pulse at least intermittently for the test operation, the frequency generator producing the clock pulse as a multiple or as a submultiple of the sampling rate.

Abstract: With a sensor having a centrifugal mass in the form of a balancing rocker which is deflectable in the z-direction, to avoid asymmetrical clipping in the case of lever arms of the balancing rocker that are of different lengths, a limit-stop device, which shortens the possible deflection, is provided on the side of the shorter lever arm, or, in the case of lever arms of equal length, at least one additional mass disposed on the side on one lever arm is provided, so that the maximum mechanical deflection of the centrifugal mass is of equal magnitude on both sides of the asymmetrical balancing rocker.