Tdk Corporation

Epcos Ag

Matthias Winter

Christian Siegel

Wolfgang Pahl

Anton Leidl

Gregor Feiertag

Sebastian Walser

In a capacitively operating MEMS microphone, by varying the BIAS voltage, the pull-in point is determined and the present pull-in voltage and the corresponding pull-in capacitance between membrane and back electrode are ascertained. From the deviation of the present pull-in point from the values of a first pull-in point, these values being determined after an end test and stored in an internal memory of the MEMS microphone, and the likewise stored values at a first operating point a recalibrated BIAS voltage is determined and set in order thereby to bring the sensitivity closer again to that at the original first operating point.

MEMS microphone and method for self-calibration of the MEMS microphone

A microphone package wherein an MEMS microphone chip (MIC) is mounted on a substrate (SUB) and is sealed with a cover (ABD) with respect to the substrate. The membrane (MMB) of the microphone chip is connected to a sound entry opening (SEO) in the substrate via an acoustic channel. As a result of defined dimensioning of, in particular, the cross section and length of sound entry opening and channel, an acoustic low-pass filter is formed, the &#x2212;3 dB attenuation point of which is significantly below the natural resonance of microphone membrane and package.

MEMS microphone

Growing community of inventors

Grosskarolinenfeld, Germany

Matthias Winter