The present disclosure is directed to micro-electromechanical system (MEMS) accelerometers that are configured for a user interface mode and a true wireless stereo (TWS) mode of an audio device. The accelerometers are fabricated with specific electromechanical parameters, such as mass, stiffness, active capacitance, and bonding pressure. As a result of the specific electromechanical parameters, the accelerometers have a resonance frequency, quality factor, sensitivity, and Brownian noise density that are suitable for both the user interface mode and the TWS mode.

According to one embodiment, a sensor includes a first detection element, and a processing part. The first detection element includes a base body, a first supporter fixed to the base body, a first movable part, first and second counter conductive parts. The first movable part is supported by the first supporter and separated from the base body. The first movable part includes a first movable base part supported by the first supporter, a second movable base part connected with the first movable base part, a first movable beam including a first beam, and a second movable beam including a second beam. The first beam includes a first end portion and a first other end portion. The second beam includes a second end portion and a second other end portion. The first counter conductive part faces the first movable beam. The second counter conductive part faces the second movable beam.

The present disclosure related to a micro-electromechanical system (MEMS) device and a method of forming the same. The MEMS device includes a substrate, a cavity, an interconnection structure and a proof mass. The substrate includes a first surface and a second surface opposite to the first surface. The cavity is disposed in the substrate to extend between the first surface and the second surface. The interconnection structure is disposed on the first surface of the substrate, over the cavity. The proof mass is disposed on the interconnection structure, wherein the proof mass is partially suspended over the interconnection structure.

The present disclosure relates to a micro-electromechanical system (MEMS) device and a method of forming the same. The MEMS device includes a substrate, a cavity, an interconnection structure and a proof mass. The substrate includes a first surface and a second surface opposite to the first surface. The cavity is disposed in the substrate, extending between the first surface and the second surface. The interconnection structure is disposed on the first surface of the substrate, over the cavity. The proof mass is disposed in the cavity, connected to the interconnection structure, the proof mass having a thickness which is smaller than a thickness of the substrate.

The disclosure describes a magnetic circuit assembly that includes a magnet assembly and an excitation ring. The magnet assembly defines a central axis and includes a pole piece and a magnet underlying the pole piece. The excitation ring includes a base and an outer ring positioned around the magnet assembly. The base includes a platform layer underlying the magnet, an upper base layer underlying the platform layer, and a lower base layer underlying the upper base layer. The outer ring overlies the upper base layer and is configured to couple to an outer radial portion of a proof mass assembly. The platform layer and lower base layer are made from high coefficient of thermal expansion (CTE) materials, while the upper base layer and outer ring are made from low CTE materials. Each relatively high CTE material has a higher CTE than each relatively low CTE material.

According to one embodiment, a sensor includes a first detection element, and a controller. The first detection element includes a base body, a first support portion, a first movable member, a first detection electrode, and a first counter detection electrode. The first support portion is fixed to the base body. The first movable member is supported by the first support portion. The first detection electrode and the first counter detection electrodes are fixed to the base body. The first movable member includes a first movable portion. The first movable portion includes a first beam, a first conductive extending portion, and a first connecting portion. The first conductive extending portion includes a first extending portion, a first extending other portion, and a first extending intermediate. The first extending portion is between the first detection electrode and the first counter detection electrodes. The controller includes a first differential circuit.

The disclosure describes techniques to damp the proof mass motion of an accelerometer while achieving an underdamped resonator. In an example of an in-plane micro-electromechanical systems (MEMS) VBA, the proof mass may contain one or more damping combs that include one or more banks of rotor comb fingers attached to the proof mass. The rotor comb fingers may be interdigitated with stator comb fingers that are attached to fixed geometry. These damping comb fingers may provide air damping for the proof mass when the MEMS die is placed into a package containing a pressure above a vacuum. The geometry of the damping combs with a reduced air gap and large overlap area between the rotor comb fingers and stator comb fingers. The geometry of resonator of the VBA of this disclosure may be configured to avoid air damping.

The disclosure describes techniques to adjust the geometry of a pendulous proof mass VBA to operate with sufficient signal-to-noise performance while avoiding nonlinear mechanical coupling at specified frequencies. The techniques of this disclosure include adding anchor support flexures to a resonator connection structure, adjusting shape, thickness, and the material of VBA components and of the VBA support structure to both control the frequency of any mechanical resonant modes and to adjust the mechanical mode frequencies away from desired operating frequencies and, in some examples, away from harmonics of desired operating frequencies.

The accelerometric sensor has a suspended region, mobile with respect to a supporting structure, and a sensing assembly coupled to the suspended region and configured to detect a movement of the suspended region with respect to the supporting structure. The suspended region has a geometry variable between at least two configurations associated with respective centroids, different from each other. The suspended region is formed by a first region rotatably anchored to the supporting structure and by a second region coupled to the first region through elastic connection elements configured to allow a relative movement of the second region with respect to the first region. A driving assembly is coupled to the second region so as to control the relative movement of the latter with respect to the first region.

According to one embodiment, a sensor includes a first detection element. The first detection element includes a base body, a first support member fixed to the base body, a conductive first movable member, and a first conductive part fixed to the base body. The first movable member includes first, second, third, fourth and fifth movable parts. In a second direction crossing a first direction from the base body toward the first movable member, the third movable part is between the first and second movable parts. In the second direction, the fourth movable part is between the first and third movable parts. In the second direction, the fifth movable part is between the third and second movable parts. The first movable part is supported by the first support member. The second, third, fourth and fifth movable parts are separated from the base body.