| 摘要 |
<p>Within an integrated device for capacitive measuring of nanometer distances above a well formed in a substrate, one below the other, there are situated electrically conductive and electrically insulated plates, namely, a movable plate connected to the substrate, a sensing plate connected to an input of a follower amplifier, and a plate building up the electric field and being electrically insulated from the well and connected to a pulsing generator. The well is connected to the output of the follower amplifier and projects from below the sensing plate to the extent that the capacitance of the sensing plate with respect to the substrate is reduced to a minimum. At the drain of an input transistor within the follower amplifier a potential is maintained, which potential is changing in the same way as a potential at the output of the follower amplifier. The device of the invention makes possible an absolute measurement of distances. By an appropriate topology of the plates of the micromechanical sensor the parasitic capacitance of this sensor is eliminated, by means of an active circuit. The effect of parasitic capacitances in the pertaining electronic circuit is also eliminated.</p> |
