CN218041775U

CN218041775U - MEMS audio transducer with electronic unit

Info

Publication number: CN218041775U
Application number: CN202221501701.XU
Authority: CN
Inventors: 安德里亚·韦斯高尼·克莱里西·贝尔特拉米; 费鲁乔·博托尼
Original assignee: USound GmbH
Current assignee: USound GmbH
Priority date: 2022-01-03
Filing date: 2022-06-15
Publication date: 2022-12-13
Anticipated expiration: 2032-06-15

Abstract

An audio converter arrangement (1) having: a MEMS audio transducer (2) for generating sound waves, having at least one transducer structure (73), in particular a piezoelectric transducer structure; an electronic unit (601) for controlling at least one transducer structure (73) of a MEMS audio transducer (2), comprising an electronic control device (602) and an energy source (603); the energy source (603) is electrically connected with the electronic control device (602) and provides a DC input signal (608) for the electronic control device (602); wherein the electronic control device (602) is configured to process an audio input signal (604) comprising an AC input signal (606) into an audio output signal (605) comprising an AC output signal (607) and a DC output signal (609), and to control the converter structure (73) with the audio output signal (605). According to the application, the electronic unit (601) is constructed such that the transducer structure (73) of the MEMS audio transducer (2) can be controlled with a DC output signal (609) of less than or equal to 3V.

Description

MEMS audio transducer with electronic unit

Technical Field

The utility model relates to an audio converter device, it has: a MEMS audio transducer for generating acoustic waves, said MEMS audio transducer having at least one transducer structure; an electronic unit for controlling the at least one transducer structure of the MEMS audio transducer, the electronic unit comprising an electronic control device and an energy source, wherein the energy source is electrically connected with the electronic control device and provides a DC input signal to the electronic control device, and wherein the electronic control device is constructed in such a way that an audio input signal comprising an AC input signal is processed into an audio output signal comprising an AC output signal and a DC output signal, and the transducer structure is controlled with the audio output signal.

MEMS audio transducers of this type are of extremely small size and are therefore embedded, for example, as loudspeakers and/or microphones in hearing aids, in-ear headphones, mobile telephones, tablets and other electronic devices which provide only a small installation space.

Background

The name MEMS stands for micro-electro-mechanical systems. DE 10 2012 220 819 A1, for example, discloses MEMS audio transducers and MEMS loudspeakers for sound production. Sound is emitted by an oscillatably supported diaphragm of the MEMS loudspeaker. Such audio transducers are customized to the sound requirements and other requirements of the respective application area and are composed of a plurality of different elements.

SUMMERY OF THE UTILITY MODEL

The object of the utility model is to improve the audio converter device that has MEMS audio converter.

The solution to achieve the above object is an audio transducer arrangement with a MEMS audio transducer for generating sound waves, the MEMS audio transducer having at least one transducer structure, in particular a piezoelectric transducer structure. The audio transducer arrangement comprises an electronic unit for controlling the at least one transducer structure of the MEMS audio transducer. The electronic unit comprises an electronic control device and an energy source. The energy source is electrically connected to the electronic control device and provides a DC input signal to the electronic control device. The electronic control device is constructed in such a way that an audio input signal is processed into an audio output signal. Wherein the audio input signal comprises an AC input signal and the audio output signal comprises an AC output signal and a DC output signal. The electronic control device is constructed in such a way that the converter structure is controlled with the audio output signal. The electronic unit is constructed in such a way that the converter structure of the MEMS audio converter can be controlled with a DC output signal of less than or equal to 3V. This reduces the load in the converter structure and thus extends the life of the converter structure.

Advantageously, the energy source has a voltage of 3V, such that the DC input signal is 3V.

It is also advantageous for the electronic control device to comprise a control unit, in particular an ASIC, which can be used to process an audio input signal into an audio output signal.

In an advantageous development of the invention, the electronic control device is designed in such a way that it keeps the DC input signal of the energy source constant, so that the DC output signal corresponds to the DC input signal.

Alternatively, the electronic control device is constructed in such a way that it attenuates the DC input signal of the energy source so that the DC output signal is smaller than the DC input signal. To this end, advantageously, the electronic control device comprises a resistor attenuating the DC input signal of the energy source, so that the DC output signal is smaller than the DC input signal.

Advantageously, the MEMS audio transducer for generating and/or detecting sound waves has a diaphragm carrier. The MEMS acoustic transducer preferably comprises a membrane which is connected in its edge region to a membrane carrier and can be oscillated along a lifting axis relative to the membrane carrier. The MEMS audio transducer preferably also has a MEMS element with a transducer structure which is deflectable at least along the lifting axis. For this purpose, the converter structure is preferably connected to the membrane.

Advantageously, the MEMS audio transducer further comprises a housing, the housing at least partially forming an acoustic cavity of the MEMS audio transducer. The acoustic cavity of the MEMS audio transducer is preferably constructed on one side, in particular the back side, of the membrane and is closed by a housing. To enable exchange of air between the cavity and the environment, the MEMS audio transducer preferably comprises a cavity opening built into the housing. The cavity opening is preferably closed by a gas-permeable porous protective element. This prevents dirt and/or moisture from the environment from entering the cavity. In order to improve the total harmonic distortion of the MEMS audio transducer, the porous protective element preferably has 48 to 52MKS Rayls, in particular 50MKS Rayls (or 5.0CGS acoustic ohm/1 cm) ² ) The acoustic impedance of (c). For this purpose, the porous protective element preferably has a pore size of 34 μm to 38 μm, in particular 36 μm, additionally or alternatively.

Advantageously, the porous protective element is a grid and/or is constructed as a grid element.

It is also advantageous if the porous protective element is made of a textile and/or is constructed as a fabric and/or a braid.

According to an advantageous development of the invention, the porous protective element has a volume of more than 2900L/m ² s @20mmWG, particularly in excess of 3000L/m ² s @ 20mmWG.

It is also advantageous for the porous protective element to have a thickness of 58 μm to 66 μm, in particular 62 μm, in the axial direction of the cavity opening.

Advantageously, said porous protection element has a density of 35g/m ² To 41g/m ² In particular 38g/m ² The weight of (c).

Also advantageously, the porous protection element has an elongation at break of more than 18%.

To ensure good air permeability, the porous protective element advantageously has an open pore area of 22% to 26%, in particular 24%.

In the case of a planar design of the porous protective element and/or a sandwich-like arrangement between two housing layers of the housing and/or bonding of these housing layers, the production costs of the MEMS audio transducer can be reduced.

Advantageously, the porous protective element is constructed to be semi-permeable, in particular air-permeable and water-impermeable. To this end, the porous protective element advantageously has a hydrophobic coating.

According to an advantageous development of the invention, the cavity opening is formed in a cavity wall or in a cavity bottom of the housing.

Advantageously, the transducer structure comprises at least one piezoelectric layer. The piezoelectric layer preferably has a thickness exceeding 1 μm. Wherein the thickness is measured in a direction of the lifting axis. This enhances robustness to electrical faults. Thereby, it is possible to prevent the piezoelectric layer from breaking in case the MEMS audio transducer is subjected to a high mechanical load, for example in case the MEMS audio transducer is dropped on the ground.

Advantageously, the piezoelectric layer has a thickness of 1.1 μm to 2.5 μm.

Particularly advantageously, the piezoelectric layer has a thickness of 2 μm.

Advantageously, the converter structure is composed of a plurality of layers stacked in a sandwich.

It is also advantageous for the piezoelectric layer to be arranged between two electrode layers.

Furthermore, advantageously, the converter structure has two piezoelectric layers spaced apart from one another in the stacking direction.

Advantageously, the MEMS audio transducer comprises a coupling element capable of oscillating with the diaphragm along the lifting axis and indirectly connecting the diaphragm and the transducer structure together. Furthermore, advantageously, the membrane is flexible.

In order to reinforce the membrane in a region, in particular a central region, the MEMS acoustic transducer advantageously has a rigid reinforcing element, which is fastened to the membrane. By means of the enhancing element, the sound pressure power of the MEMS audio transducer can be increased. However, there is a disadvantage in that the weight of the diaphragm increases, so that the response characteristics of the diaphragm are deteriorated. The reinforcing element preferably has at least one groove. This can reduce the weight of the reinforcing member and improve the response characteristics. The reinforcing element simultaneously retains sufficient strength so that the membrane is further optimally reinforced.

Advantageously, the groove passes completely through the reinforcing element, so that the groove has one opening at each of its two ends.

Furthermore, the reinforcing element advantageously has outer grooves which, in a plan view of the reinforcing element, are arranged in edge sections of the reinforcing element.

It is also advantageous that the outer grooves are arranged side by side in such a way that they follow the outer contour of the reinforcing element.

Furthermore, the outer groove is advantageously designed as an elongated hole, in particular in a plan view. The elongated hole preferably has rounded ends.

It is also advantageous if the outer grooves each have a longitudinal axis. Also advantageously, the longitudinal axis of the outer groove intersects the centre of the reinforcing element.

Furthermore, the reinforcing element advantageously has inner grooves which, in a plan view of the reinforcing element, are arranged in the inner section of the reinforcing element.

Advantageously, the inner recesses are arranged next to one another and are each separated by a web.

Likewise advantageously, the inner groove is designed as a circular arc segment.

Also advantageously, the reinforcing element has a central groove in its centre.

Furthermore, the central recess is advantageously circular in top view.

Furthermore, it is advantageous if the reinforcing element has a central elevation in a side view, so that a shoulder is constructed between the edge section and the inner section in which the inner groove and/or the central groove is arranged.

It is also advantageous for the coupling element to be fastened on the end of the projection.

It is also advantageous if the membrane is fastened to the side of the reinforcing element facing away from the projection.

Also advantageously, the reinforcing element is circular in plan view.

The present invention provides a method of manufacturing a MEMS audio transducer in which the aforementioned features can be applied separately or combined arbitrarily. According to the manufacturing method, the reinforcing element is manufactured by etching an aluminum foil. Advantageously, the aluminum foil is subjected to double-sided etching.

To prevent damage to the membrane and/or the transducer structure, the MEMS audio transducer advantageously has a first stopper mechanism and/or a second stopper mechanism. The first stop mechanism is preferably arranged in the region of the coupling element in a cross-sectional view of the MEMS audio transducer in order to limit the oscillation of the coupling element along the lifting axis in at least one direction. In a cross-sectional view of the MEMS audio transducer, the second stop mechanism is preferably arranged in the region of the transducer structure so as to limit oscillation of the transducer structure along the lifting axis in at least one direction. Sensitive diaphragm and/or transducer structures are protected from damage by the stopper mechanism of the present invention, which damage results from excessive movement of the diaphragm based on excessive sound pressure or external vibration or shock.

Advantageously, the first stop mechanism has a coupling element stop which is arranged opposite the coupling element in the direction of the lifting axis, is spaced apart from this coupling element in the inactive position of the coupling element and strikes the coupling element with maximum deflection. In addition or alternatively, it is advantageous if the second stop mechanism has a switch structure stop which is arranged opposite the switch structure in the direction of the lifting axis and which, in the inactive position of the switch structure, is spaced apart from this switch structure and impinges on the switch structure with a maximum degree of deflection.

In an advantageous development of the invention, in a cross-sectional view of the MEMS audio transducer, the coupling element stop and/or the transducer structure stop have the same or different distances from the coupling element and/or the transducer structure in the direction of the lifting axis in the inactive position of the membrane.

It is also advantageous if the coupling element stop and/or the converter structure stop is/are formed on the printed circuit board and/or on the housing part.

Advantageously, the coupling element stop and/or the transducer structure stop are arranged in a cavity of the MEMS audio transducer. The term "cavity" refers to an acoustic cavity built on the back side of the diaphragm.

It is also advantageous if, in a cross-sectional view of the MEMS audio transducer, the coupling element stop and/or the transducer structure stop is arranged in the region of a cavity of the printed circuit board or a cavity of the housing part. Wherein the respective cavity may form at least part of a cavity of the MEMS audio transducer.

A structurally simple solution can be achieved by: advantageously, the coupling element stop and/or the converter structure stop are each formed on a free end of the projection. In this connection, it is advantageous if the at least one projection extends from the cavity bottom and/or the cavity wall of the cavity into the cavity and/or in the direction of the coupling element and/or the transducer structure.

Advantageously, the first stop mechanism comprises a first counter-stop which limits the oscillation of the coupling element along the lifting axis in a second direction opposite to the first direction. In this connection, it is also advantageous if, in a cross-sectional view of the MEMS audio transducer, the first mating stop is arranged opposite the coupling element stop.

Furthermore, advantageously, the second stopper mechanism has a second mating stop which is arranged opposite the transducer structure stop in a cross-sectional view of the MEMS audio transducer.

Advantageously, in a cross-sectional view of the MEMS audio transducer, the first and/or second mating stop is arranged in the region of the sound transmission channel.

Furthermore, it is advantageous if the MEMS audio transducer has a third stop mechanism which is embodied in a cross-sectional view of the MEMS audio transducer in the region of the membrane in order to limit the oscillation of the membrane in at least one direction along the lifting axis, and if the third stop mechanism has a first stop which is arranged opposite the membrane in the direction of the lifting axis, is spaced apart from this membrane in the inactive position of the membrane and impinges on the membrane with a maximum deflection.

Advantageously, the membrane has a reinforcing element which is fastened on a side of the membrane facing towards or away from the MEMS unit.

It is also advantageous if the diaphragm, in particular the reinforcing element, is designed in correspondence with the first, second and/or third stop means and/or impinges on the first counter stop, the second counter stop and/or the second stop when deflected in the second direction.

Furthermore, it is advantageous if the coupling element stop, the transducer structure stop and/or the first stop are formed at least partially on the MEMS unit, the housing part and/or the printed circuit board.

Advantageously, the end face of the carrier substrate facing the membrane is designed as a first stop.

Furthermore, it is advantageous if the diaphragm, in particular the reinforcing element, has a stop surface corresponding to the first counter stop, the second counter stop and/or the first stop.

Advantageously, the diaphragm, in particular the reinforcing element, has a coupling surface in the region of which the diaphragm is indirectly connected to the converter structure via a coupling element.

Advantageously, the stopper mechanism has a reinforcing element arranged on one side of the membrane. Furthermore, it is advantageous if the stopper mechanism comprises a first stop arranged opposite the reinforcing element, which is spaced from this diaphragm in the inactive position of the diaphragm and against which the reinforcing element impinges with maximum deflection.

Advantageously, the MEMS element is a MEMS actuator and/or a MEMS sensor. It is also advantageous that the MEMS element co-acts with the membrane to convert the electrical signal into an acoustic wave that can be heard. Of course, acoustic waves that can be heard can also be converted into electrical signals.

Also advantageously, the MEMS element comprises a carrier substrate. The converter structure is preferably fastened to the carrier substrate. The transducer structure is preferably constructed as at least one cantilever. The at least one cantilever preferably comprises a first end connected to the carrier substrate and a free end facing away from this carrier substrate. The free end can be pivoted along the lifting axis and is connected to the coupling element, in particular by means of at least one spring element. The carrier substrate is preferably made of silicon.

Advantageously, the first stop is at least partially formed on the MEMS element, in particular on a carrier substrate of the MEMS element, in particular of the MEMS actuator or MEMS sensor. Additionally or alternatively, the first stop can be formed at least partially on the housing part and/or on the printed circuit board. Thus, advantageously, no additional components are required to form the first stop. Alternatively or additionally, the reinforcement element is fastened to the membrane on the side facing the MEMS unit. In the event of an impact on the first stop, the membrane is thus protected by the reinforcing element.

Advantageously, the end face of the carrier substrate of the MEMS element, in particular of the MEMS actuator and/or MEMS sensor, which faces the membrane is designed as a first stop. In addition or alternatively, it is advantageous if the MEMS unit has a transducer structure, in particular an actuator structure and/or a sensor structure, in particular on a side of the carrier substrate facing away from the membrane. The transducer structure is preferably formed by a piezoelectric layer.

In an advantageous development of the invention, the edge region of the membrane is fastened in a fastening region of the membrane carrier, which fastening region is preferably spaced apart from the MEMS unit, in particular from the carrier substrate, in the x, y and z directions. By separating the diaphragm suspension from the carrier substrate, the acoustically active surface of the diaphragm is constructed larger than the carrier substrate.

In a further advantageous embodiment of the invention, the at least one housing part and/or the printed circuit board forms a membrane carrier, wherein the membrane is preferably fastened between two of these components.

Advantageously, the membrane has an outer elastic region, in particular designed as a bulge. This area is preferably arranged adjacent to the edge area. Alternatively or additionally, the membrane has an inner reinforcing region in which reinforcing elements are arranged. The elastic region enables the membrane to oscillate relative to the membrane carrier. In this way, the inner reinforcing region of the membrane with the reinforcing element can oscillate relative to the outer edge region of the membrane and/or its fastening region.

It is also advantageous if the reinforcing region and/or the reinforcing element is in particular directly adjacent to the elastic region.

In an advantageous development of the invention, the reinforcing element can be formed from plastic, metal and/or fiber composite material. It is also advantageous for the reinforcing element to be plate-shaped, which is bonded to the membrane, in particular made of silicon, and/or to extend over the entire reinforcing area. The membrane has a greater strength in its stiffening region or due to the stiffening element and thus has improved acoustic properties, in particular with regard to the achievable sound volume, frequency range and/or signal fidelity.

In a further advantageous embodiment of the invention, the reinforcing element has a third stop surface corresponding to the first stop. The third stop surface is preferably designed as a closed frame.

Preferably, the reinforcing element has a coupling surface, which is preferably arranged within the frame-like third stop surface and/or in the region of the coupling surface, the reinforcing element being connected to the converter structure, in particular indirectly, by means of a coupling element.

Furthermore, it is advantageous if the third stop surface and the coupling surface are spaced apart from one another in the direction of the lifting axis or in the z-direction and/or are connected by an intermediate region of the reinforcing element, which is in particular funnel-shaped. The total area of the diaphragm is advantageously increased without increasing the diameter of the diaphragm, thereby saving structural space and material while improving the acoustic properties of the diaphragm.

According to a further preferred embodiment of the invention, the carrier substrate and the coupling element are made of the same substrate, in particular a silicon substrate, and have in particular the same thickness.

In an advantageous development of the invention, the third stop mechanism comprises a second stop which limits the oscillation of the diaphragm along the lifting axis in a second direction opposite to the first direction, wherein the second stop is preferably arranged in the sound transmission channel formed by the housing part. The membrane is better protected against damage by a second stop acting in the opposite direction to the first stop.

Preferably, the first and second stops are arranged opposite each other and/or the reinforcing element is arranged between and spaced apart from the two stops.

Advantageously, the MEMS audio transducer comprises a printed circuit board with a completely embedded ASIC and/or a recess through the printed circuit board, wherein preferably a MEMS unit is arranged on a first opening of the recess and/or a housing part is arranged on a second opening of the recess to form a closed cavity.

Drawings

Further advantages of the invention are described with reference to the following description of the embodiments. Wherein:

figure 1 is a perspective cross-sectional view of a MEMS audio transducer,

figure 2 is a schematic side cross-sectional view of the MEMS audio transducer of figure 1,

fig. 3 is a schematic side cross-sectional view of a first embodiment of a MEMS audio transducer, having a diaphragm oscillating outwardly in a first direction,

fig. 4 is a schematic side cross-sectional view of a first embodiment of a MEMS audio transducer, having a diaphragm oscillating outwardly in a second direction,

figure 5 is a perspective cross-sectional view of another MEMS audio transducer,

figure 6 is a schematic side cross-sectional view of the MEMS audio transducer of figure 5,

figure 7 is a schematic side cross-sectional view of a second embodiment of a MEMS audio transducer,

figure 8 is a perspective view of a stiffening element for stiffening a membrane of a MEMS audio transducer particularly in the previous embodiments,

figure 9 is a top view of the reinforcing element on the side for securing the coupling element,

figure 10 is a side view of the reinforcing element,

FIG. 11 is a partial cross-section of a MEMS element of a MEMS audio transducer, an

Fig. 12 is a schematic diagram of the signal processing of the audio transducer arrangement.

Detailed Description

In the following description of the drawings, to define the relationship between various elements, relative terms such as above, below, up, down, over, under, left, right, vertical, and horizontal are used with reference to the corresponding orientation of the object as illustrated in the drawings. Of course, these terms may change as one moves away from the illustrated orientation of the device and/or element. Thus, for example, in an inverted orientation of the device and/or elements relative to the drawings, features described above in the following description of the drawings are now below. Accordingly, the relative terms used are only used to simplify the description of the relative relationships between the various devices and/or elements described below.

Fig. 1 to 2 show different views of an audio transducer arrangement 1 with a MEMS audio transducer 2. The MEMS audio transducer 2 is adapted to generate and/or detect sound waves in an audible wavelength spectrum. For this purpose, the audio transducer has a diaphragm 30 and a diaphragm carrier 40. The diaphragm 30 is connected in its edge region 37 to the diaphragm carrier 40 and can be oscillated along a lifting axis 50, in particular the z axis, relative to the diaphragm carrier 40. The lift shaft 50 is generally perpendicular to the diaphragm 30. The MEMS audio transducer 2 further comprises a housing 501, which housing 501 at least partly forms the acoustic cavity 90 of the MEMS audio transducer 2. The acoustic cavity 90 of the MEMS audio transducer 2 is constructed on one side, in particular the back side, of the membrane 30 and is closed by a housing 501. The housing 501 may be constructed in multiple components.

The MEMS audio transducer 2 has a stiffening element 31 for stiffening the flexible membrane 30.

The MEMS audio transducer 2 further has a third stop mechanism 60 adapted to limit oscillation of the diaphragm 30 in at least one direction 51. To this end, the third stopper mechanism 60 includes the reinforcing member 31. This reinforcing element 31 is arranged on one side of the membrane 30, preferably on the bottom side of the membrane 30. Wherein the reinforcing element 31 may be constructed according to the embodiments shown in fig. 8, 9 and 10. On the other hand, the third stop mechanism 60 has a stop 61 arranged opposite the reinforcement element 31, which stop is spaced apart from the diaphragm 30 in the inactive position of the diaphragm 30 as shown in fig. 1 and 2 and against which the reinforcement element 31 strikes in the event of a maximum deflection of the diaphragm 30 in the direction 51 as shown in fig. 3.

In this example, the third stopper mechanism 60 also has a second stop 62 that limits oscillation of the diaphragm 30 along the lift shaft 50 in a second direction 52 opposite the first direction 51. The second stop 62 is likewise spaced apart from the diaphragm 30 in the inactive position of the diaphragm 30, as shown in fig. 1 and 2, wherein the reinforcing element 31, as shown in fig. 4, strikes the second stop 62 with maximum deflection of the diaphragm 30 in the direction 52. In this case, the membrane 30 is arranged between the second stop 62 and the reinforcing element 31.

Thus, as shown in fig. 3, the diaphragm 30 oscillates or deflects downward to the extent that the reinforcing member 31 impinges on the first stop 61, whereas as shown in fig. 4, the diaphragm 30 oscillates or deflects upward to the extent that the reinforcing member 31 impinges on the second stop 62 of the third stopper mechanism 60.

As can be seen in particular also from fig. 1 to 4, the two stops 61, 62 are arranged opposite one another, with the reinforcing element 31 being arranged between them and spaced apart from them. The second stop 62 is arranged on the upper housing part 81 above the diaphragm 30, and in particular in a sound channel 92 formed by the upper housing part 81.

While the first stop 61 is arranged on a carrier substrate 71 of the MEMS unit 70, in particular of the MEMS actuator and/or MEMS sensor, or is formed by one side of the carrier substrate 71. The MEMS unit 70 is arranged below the membrane 30 and/or substantially parallel to this membrane. The MEMS element 70 works in conjunction with the diaphragm 30 to convert electrical signals into acoustic waves that can be heard, or vice versa. For this purpose, the MEMS unit 70 comprises a transducer structure 73, in particular an actuator structure and/or a sensor structure. This structure is preferably a piezoelectric structure. Furthermore, the transducer structure 73 is arranged on a side of the carrier substrate 71 facing away from the membrane 30. In this example, an end side 72 of the carrier substrate 71 of the MEMS element 70, in particular of the MEMS actuator and/or MEMS sensor, facing the membrane 30 is designed as a stop 61. However, unlike the case shown here, the first stop 61 can also be formed on a housing part, such as the intermediate housing part 83, and/or on a printed circuit board, such as the printed circuit board 84. The reinforcing element 31 is fastened to the membrane 30 on the side facing the MEMS unit 70. In addition or as an alternative, the reinforcing element 31 or an additional reinforcing element can in principle also be fastened to the membrane 30 on the side facing away from the MEMS unit 70. The reinforcing element 31 has in particular a third stop face 33 corresponding to the

stops

61, 62.

In addition to the membrane 30, the membrane carrier 40, the MEMS unit 70 and the two

housing parts

81, 83 of the MEMS audio transducer 2, the audio transducer device 1 comprises a printed circuit board 84 and a lower housing part 89. The ASIC85 is fully embedded in the printed circuit board 84. In addition to the ASIC, other passive components, such as resistors and/or E/a contacts, may also be embedded in and/or arranged on the printed circuit board.

The printed circuit board 84 has a recess 86 which passes completely through the printed circuit board and has two openings 87, 88. At the first opening 87 of the recess 86, the MEMS unit 70 is arranged. A lower housing portion 89 is disposed at a second opening 88 of the recess 86 to form a closed cavity 90. Thus, the printed circuit board 84 is disposed between the MEMS unit 70 and the lower housing portion 89.

The MEMS audio transducer 2 and in particular the MEMS unit 70 are connected with an ASIC85 with electrical contacts not shown in detail in the figure. The MEMS audio transducer 2 can thus be controlled or operated by the ASIC 85. In the case of MEMS audio transducer 2 being used as a loudspeaker, for example, the loudspeaker can be excited by ASIC85, so that diaphragm 30 is caused to oscillate relative to diaphragm carrier 40 by MEMS element 70 to generate acoustic energy. The term "cavity" 90 refers to a cavity that may be used to enhance the acoustic pressure of the MEMS audio transducer 2. A part of the cavity 90 is already formed by the recess 86 of the printed circuit board 84, so that the audio transducer device 1 or the MEMS audio transducer 2 can be provided with a relatively large and acoustically effective cavity volume in an extremely compact manner, since the cavity provided by the lower housing part 89 for forming the cavity 90 can now be smaller.

Housing portions

81, 83 and in particular lower housing portion 89 preferably have a different material than printed circuit board 84. Alternatively, however, at least one of the housing parts 81 may also be a component of the printed circuit board 84.

The audio transducer device 1 or MEMS audio transducer 2 has a substantially rectangular basic shape and is therefore easy and inexpensive to manufacture and suitable for a variety of uses. Furthermore, the audio transducer device 1 is constructed in a sandwich type, that is, the lower housing portion 89, the printed circuit board 84 and the MEMS audio transducer 2 are arranged in a stacked manner with each other. The MEMS audio transducer 2, the printed circuit board 84, and the lower housing portion 89 have the same outer diameter. Alternatively, however, the audio transducer device 1 may also have another basic shape, in particular a circular shape.

In particular, the membrane 30 made of silicon is fastened in its edge region 37 in a fastening region 41 of the membrane carrier 40, wherein the fastening region 41 is preferably spaced apart from the MEMS unit 70 and its carrier substrate 71 in the x, y and z directions. The diaphragm carrier 40 is formed here by an upper housing part 81 and a middle housing part 83, wherein the fastening area is between the two

housing parts

81, 83, and thus the diaphragm is fastened between the two housing parts. The membrane carrier 40 is frame-shaped and surrounds the membrane 30. However, unlike the case shown here, the film carrier 40 can also be formed at least partially from a printed circuit board, such as the printed circuit board 84.

The membrane 30 has, adjacent to its edge region 37, an outer elastic region 38 and an inner reinforcing region 32, the elastic region 38 being designed here in particular as a bulge 39, in which reinforcing region 32 a reinforcing element 31 is arranged. Wherein the reinforcing area 32 or the reinforcing element 31 is immediately adjacent to the elastic area 38. Elastic region 38 enables diaphragm 30 to oscillate relative to diaphragm carrier 40, and in particular enables inner reinforced region 32 to oscillate relative to outer edge region 37. The reinforcing element 31 is formed from metal and/or is plate-shaped, wherein the reinforcing element 31 extends here preferably over the entire reinforcing region 32 and is bonded to the membrane 30. The third stop surface 33, which is provided by the reinforcing element 31 and corresponds to the

stops

61, 62, is here frame-shaped and is arranged next to the likewise frame-shaped spring region 38.

In this example, the first stop 61 and the second stop 62 are likewise frame-shaped in correspondence with the third stop surface 33. The carrier substrate 71, which is provided with the first stop 61 on the end side 72, surrounds the transducer structure 73 in the form of a frame, while the upper housing part 81 has a projection 82, which projection 82 surrounds the sound inlet/outlet opening 93 of the sound channel 92 in the form of a frame and provides the second stop 62.

Inside the frame-like third stop surface 33, the reinforcing element 31 of the membrane 30 has a coupling surface 35. The third stop surface 33 and the coupling surface 35 are spaced apart from one another in the z-direction and are connected by an intermediate region 34 of the reinforcing element 31, which is here funnel-shaped. The reinforcing element 31 is glued to the membrane 30, so that the membrane 30 is also funnel-shaped. In the region of the coupling surface 35, the reinforcing element 31 is connected to the MEMS unit 70, in particular to the transducer structure 73 of the MEMS actuator and/or MEMS sensor, via a coupling element 74. The carrier substrate 71 and the coupling element 74 are made of the same substrate, in particular a silicon substrate. Thus, the carrier substrate 71 is the same thickness as the coupling element 74. However, unlike the case shown here, an adapter element can be used instead of or in addition to the coupling element 74 for connection to the converter structure 73.

Fig. 3 and 4 show an embodiment of the MEMS audio transducer 2. This audio transducer has the features of the MEMS audio transducer shown in fig. 1 and 2, wherein these features may also be present individually or in any combination. Like features have been given like reference numerals and will not be described in detail below if they have been described above. In this case, the reinforcing element 31 is constructed in particular according to the embodiment shown in fig. 8, 9 and 10.

MEMS audio transducer 2 shown in fig. 3 and 4 for generating and/or detecting sound waves in the audible wavelength spectrum comprises a membrane carrier 40 and a membrane 30, which membrane 30 is connected in its edge region to membrane carrier 40 and can oscillate along a lifting axis, in particular a z axis, relative to membrane carrier 40. Furthermore, the MEMS audio transducer 2 has a MEMS unit 70, which MEMS unit 70 has at least one transducer structure 73 which is deflectable along the lifting axis. The MEMS audio transducer 2 further comprises a coupling element 74, which coupling element 74 is capable of oscillating together with the diaphragm 30 along the lifting axis and indirectly connects the diaphragm 30 and the transducer structure 73 together. To prevent damage to the diaphragm 30 and/or the transducer structure 73, the mems audio transducer 2 further comprises a first stopper mechanism 100 and/or a second stopper mechanism 200. The first stopper mechanism 100 is arranged in the area of the coupling element 74 in the cross-sectional view of the MEMS audio transducer 2, so as to limit the oscillation of the coupling element 74 along the lifting axis in at least one direction. In a cross-sectional view of the MEMS audio transducer 2, the second stopper mechanism 200 is arranged in the region of the transducer structure 73 so as to limit the oscillation of the transducer structure 73 along the lifting axis in at least one direction.

The first stop mechanism 100 has a coupling element stop 101, which is arranged opposite the coupling element 74 in the direction of the lifting axis, is spaced apart from this coupling element 74 in the inactive position of the coupling element 74 and strikes the coupling element 74 with maximum deflection. Furthermore, the second stop mechanism 200 has a switch structure stop 201 which is arranged opposite the switch structure 73 in the direction of the lifting axis, is spaced apart from this switch structure 73 in the inactive position of the switch structure 73 and strikes the switch structure 73 with a maximum deflection.

In a cross-sectional view of the MEMS audio transducer 2, the coupling element stop 101 and/or the transducer structure stop 201 are at different distances from the coupling element 74 and/or the transducer structure 73 in the lifting axis direction in the inactive position of the diaphragm 30. Coupling element stop 101 and/or transducer structure stop 201 are formed on housing portion 89.

The coupling element stop 101 and/or the transducer structure stop 201 are arranged in the cavity 90 of the MEMS audio transducer 2. The term "cavity" refers to an acoustic cavity that is built on the backside of the diaphragm 30. In the cross-sectional view of the MEMS audio transducer 2, the coupling element stop 101 and/or the transducer structure stop 201 are arranged in the region of the cavity of the printed circuit board 84. Wherein the cavity forms part of the cavity 90 of the MEMS audio transducer 2.

The coupling element stop 101 and/or the converter structure stop 201 are formed on a free end of the

projections

102, 202, respectively. Wherein the

protrusions

102, 202 extend into the cavity 90 from the cavity bottom 94 of the cavity 90. Alternatively, the

respective protrusions

102, 202 may also extend from the cavity wall 95 into the cavity 90.

The first stop mechanism 100 includes a first mating stop 103 that limits oscillation of the coupling element 74 along the lift axis in the second direction 52 opposite the first direction 51. In a cross-sectional view of the MEMS audio transducer 2, the first counterpart stop 103 is arranged opposite the coupling element stop 101.

The second stopper mechanism 200 has a second counterpart stop 203 arranged opposite to the transducer structure stop 201 in the cross-sectional view of the MEMS audio transducer 2. In a cross-sectional view of the MEMS audio transducer 2, the first and/or

second mating stop

103, 203 is arranged in the region of the sound transmission channel 92.

The MEMS audio transducer 2 has a third stop mechanism 60, which has already been described in fig. 1 and 2, which is built into the area of the membrane 30 in the cross-sectional view of the MEMS audio transducer 2, so that the oscillation of the membrane 30 along the lifting axis is limited. Furthermore, the third stop mechanism 60 has a first stop 61, which is arranged opposite the membrane 30 in the direction of the lifting axis, is spaced apart from this membrane 30 in the inactive position of the membrane 30 and strikes the membrane 30 with maximum deflection.

The membrane 30 has a reinforcing element 31, which reinforcing element 31 is fastened on the side of the membrane 30 facing the MEMS unit 70. Alternatively, the reinforcing element 31 can also be fastened to the side of the membrane 30 facing away from the MEMS unit 70. The membrane 30, in particular the reinforcing element 31, is constructed in correspondence with the first, second and/or

third stopper mechanism

100, 200, 60. Furthermore, the diaphragm, when deflected in the second direction 52, impinges on the first mating stop 103, the second mating stop 203 and/or the second stop 62. The diaphragm 30, in particular the reinforcing element 31, has a stop surface corresponding to the first mating stop 103, the second mating stop 203 and/or the first stop 61. The diaphragm 30, in particular the reinforcing element 31, has a coupling surface 35, in the region of which the diaphragm 30 is indirectly connected to the converter structure 73 via a coupling element 74.

Fig. 5 or 6 show a further embodiment of the audio transducer device 1 and the MEMS audio transducer 2, wherein mainly the differences with respect to the described embodiments are concerned. Therefore, in fig. 5 to 7 and the following description of the further embodiments, the same reference numerals are used for features of the same and/or at least similar technical solutions and/or operating principles as in the first embodiment shown in fig. 1 to 4. If these features are not explained in detail again, the technical solution and the working principle are equivalent to the features already described above. The following differences may be combined with features of the embodiments described hereinbefore or hereinafter.

Fig. 5 and 6 show different views of another embodiment of the audio transducer device 1 and the MEMS audio transducer 2. The reinforcing element 31 is preferably constructed according to the embodiment shown in fig. 8, 9 and 10. The main difference between this embodiment and the embodiment shown in fig. 1 to 4 is the upper housing part 81. The upper housing part 81 forms a sound transmission channel 92 with an inlet/outlet opening 93, which inlet/outlet opening 93 is arranged laterally outside the MEMS audio transducer 2 or the audio transducer device 1. Housing part 81 provides additional protection, in particular for membrane 30, since it covers this membrane from the surrounding environment.

However, in this exemplary embodiment, no second stop is provided, i.e., no stop for the reinforcing element 31 of the membrane 30 is provided on the upper housing part 81. In addition, the upper housing part 81 is not an integral part of the diaphragm carrier 40. The diaphragm carrier is formed only by the intermediate housing part 83, so that the diaphragm 30 is fastened only on the intermediate housing part 83. The upper and

lower housing portions

81, 89 have an outer diameter larger than that of the foregoing embodiment, and therefore, the base surface of the audio transducer device 1 is enlarged. Furthermore, in this exemplary embodiment, the upper housing part 81 is not arranged on the middle housing part 83, but rather on the lower housing part 89 and is connected thereto, so that the two housing parts together form a housing which protectively encloses the remaining components of the audio transducer device 1 or of the MEMS audio transducer 2.

Fig. 7 shows a further embodiment of the audio transducer device 1 and the MEMS audio transducer 2. Wherein the reinforcing element 31 may be constructed according to the embodiments shown in fig. 8, 9 and 10. In this embodiment, the upper housing part 81 has a projection 82 in the sound transmission channel 92, which projection 82 is arranged above the diaphragm 30 and forms the second stop 62 of the reinforcing element 31 of the diaphragm 30.

In addition, the embodiment shown in fig. 7 includes a first stop mechanism 100, which is constructed in accordance with the embodiment shown and described with respect to fig. 3 and 4. This embodiment also includes a second stopper mechanism 200, which is constructed in accordance with the embodiment shown in fig. 3 and 4.

Fig. 8, 9 and 10 show one embodiment of the reinforcing element 31. This enhancement element may be applied to each of the aforementioned embodiments of the MEMS audio transducer 2. The reinforcing element 31 is rigid. Furthermore, the reinforcing element is circular in this embodiment. The stiffening element 31 is adapted to be fastened to the membrane 30 of the MEMS audio transducer 2. The reinforcing element 31 has at least one groove 301. The weight of the reinforcing member 31 can be reduced and the response characteristics can be improved by the groove 301. The reinforcing element 31 simultaneously retains sufficient strength so that the membrane 30 is further optimally reinforced. The groove 301 passes completely through the reinforcing element 31, so that the groove 301 has an opening 302 at each of its two ends.

According to this embodiment, the reinforcing element 31 has a special groove 301, i.e. a plurality of outer grooves 303. As shown in fig. 8 and 9, these outer grooves are arranged in the edge section 304 of the reinforcing element 31. The outer grooves 303 are arranged side by side in such a way that they follow the outer contour 305 of the reinforcing element 31. In the present exemplary embodiment, the outer contour 305 of the reinforcing element 31 is designed as a rounded circle. Thus, the outer grooves 303 are also arranged in a circle along the circumference of the reinforcing element 31.

The outer groove 303 is configured here as an elongated hole. Furthermore, the elongated holes each have a longitudinal axis, wherein the outer grooves 303 are oriented such that their longitudinal axes intersect at the center 306 of the reinforcing element 31.

As shown in fig. 8 and 9, the reinforcing element 31 also has an inner groove 307. In the top view shown in fig. 9, these inner grooves 307 are arranged in the inner section 308 of the reinforcing element 31. The inner grooves 307 are arranged side by side. Furthermore, the inner grooves 307 are each separated by a spacer 309. The inner groove 307 is constructed as a circular arc segment.

Furthermore, as shown in fig. 8 and 9, the reinforcing element 31 has a central groove 310 in its center 306. The central recess 310 is circular in plan view. The central recess 310 is preferably designed as a blind hole. Thus, the central groove 310 does not pass completely through the reinforcing element 31.

As shown in fig. 10, the reinforcing element 31 has a central projection 311 in a side view. By means of this projection 311, a shoulder 312 is constructed between the edge section 304 and the inner section 308. An inner groove 307 and a central groove 310 are arranged in the inner section 308.

As shown in fig. 10, the projection 311 has a free end 313. The coupling element 74 is fastened to this free end 313. The membrane 30 is fastened to the side of the reinforcement element 31 facing away from the bulge 311.

Fig. 11 shows a partial cross section of a MEMS element 70 of the MEMS audio transducer 2. The MEMS unit 70 comprises a carrier substrate 71, in particular made of silicon. MEMS unit 70 also includes a transducer structure 73. The transducer structure 73 is arranged on the carrier substrate 71. Furthermore, the transducer structure 73 is connected to the membrane 30 by means of a coupling element 74. The transducer structure 73 comprises at least one

piezoelectric layer

401, 402. The

piezoelectric layers

401, 402 have a thickness exceeding 1 μm. This enhances robustness to electrical faults. Thereby, the

piezoelectric layers

401, 402 can be prevented from breaking when the MEMS audio transducer 2 is subjected to a high mechanical load, for example in case the MEMS audio transducer 2 is dropped on the ground. Advantageously, the

piezoelectric layers

401, 402 have a thickness of 1.1 μm to 2.5 μm. Particularly advantageously, the

piezoelectric layers

401, 402 have a thickness of 2 μm.

As shown in fig. 11, the converter structure 73 is made up of a plurality of layers stacked in a sandwich. The

piezoelectric layers

401, 402 are arranged between two

electrode layers

403, 404.

According to the present embodiment, the transducer structure 73 comprises two

piezoelectric layers

401, 402. The piezoelectric layers are spaced apart from each other in the stacking direction. An intermediate layer 405 is arranged between the two

piezoelectric layers

401, 402. Optionally, the transducer structure may have at least one carrier layer 406.

As previously mentioned, the aforementioned embodiment of the MEMS audio transducer 2 comprises a housing 501, which housing 501 at least partly forms the acoustic cavity 90 of the MEMS audio transducer 2. The acoustic cavity 90 of the MEMS audio transducer 2 is built on one side, in particular the back side, of the membrane 30 and is closed by a housing 501. To enable exchange of air between the cavity 90 and the environment, the MEMS audio transducer 2 comprises a cavity opening 502 built into the housing 501 according to the embodiments shown in fig. 1-2, 3-4, 5-6 and 7. The cavity opening 502 is formed in the cavity bottom 94 of the housing 501. Alternatively, the cavity opening 502 may also be built into the cavity wall 95 of the housing 501.

The cavity opening 502 is closed by a gas-permeable porous protective element 503. This prevents environmental contaminants and/or moisture from entering the cavity 90. In order to improve the total harmonic distortion of the MEMS audio converter 2, the porous protection element 503 has 48MKS Rayls to 52MKS Rayls, in particular 50MKS Rayls (or 5.0CGS acoustic ohm/1 cm) ² ) The acoustic impedance of (c). To this end, the porous protective element 503 has, additionally or alternatively, a pore diameter of 34 μm to 38 μm, in particular 36 μm. The porous protection element 503 is here constructed as a grid. Furthermore, the porous protection element 503 is made of textile and/or is constructed as a fabric and/or a braid. The porous protection element 503 has a capacitance in excess of 2900L/m ² s @20mmWG, particularly in excess of 3000L/m ² s @ 20mmWG. The porous protective element 503 has a thickness of 58 μm to 66 μm, in particular 62 μm, in the axial direction of the cavity opening 502. The porous protective member 503 also has 35g/m ² To 41g/m ² In particular 38g/m ² The weight of (c). The porous protective element 503 also has an elongation at break of more than 18%. To ensure good air permeability, the porous protective element 503 has an open area of 22% to 26%, in particular 24%.

In the case of a planar design of the perforated protective element 503 and/or a sandwich-type arrangement between and/or with the two

housing layers

504, 505 of the housing 501, in particular of the cavity bottom 94, the production costs of the MEMS audio transducer 2 can be reduced.

Advantageously, the protective element 503 is constructed to be semi-permeable, in particular air-permeable and water-impermeable. For this purpose, the porous protective element advantageously has a hydrophobic coating, not shown here.

Fig. 12 shows a schematic diagram of the signal processing of the previously described embodiment of the audio transducer device 1. As has already been explained in detail in the above description, the audio transducer arrangement 1 comprises a MEMS audio transducer 2 for generating sound waves, which has at least one transducer structure 73, in particular a piezoelectric transducer structure (see fig. 1 to 7). The transducer structure 73 of the MEMS audio transducer is not shown in detail in fig. 12. The MEMS audio transducer 2 of fig. 12 may be constructed in accordance with the description hereinbefore, and the features mentioned therein may be applied individually or in any combination.

The audio transducer arrangement 1 further comprises an electronic unit 601 for controlling the at least one transducer structure 73 of the MEMS audio transducer 2. The electronic unit 601 comprises an electronic control device 602 and an energy source 603. The energy source 603 is electrically connected to the electronic control device 602 and provides a DC input signal 608 to this electronic control device 602. The electronic control device 602 is designed to process an audio input signal 604 of an audio source, not shown here, into an audio output signal 605. Wherein the audio input signal 604 comprises an AC input signal 606. An AC output signal 607 of the audio output signal 605 is generated from this AC input signal 606. The audio output signal 605 also contains a DC output signal 609. This DC output signal 609 is formed by a DC input signal 608 of the energy source 603.

The electronic control device 602 is constructed in such a way that the converter structure 73 is controlled by an audio output signal 605, which audio output signal 605 comprises an AC output signal 607 and a DC output signal 609. Where the AC output signal 607 is used to sound. The DC output signal 609 is used to stabilize the converter structure 73.

The electronic unit 601 is constructed in such a way that the converter structure 73 of the MEMS audio converter 2 is controlled with a DC output signal 609 of less than or equal to 3V. This reduces the load on the converter structure 73 when stabilized by the DC output signal 609. Thereby, the lifetime of the converter structure 73 may be extended. For this purpose, the energy source 603 may already have a voltage of 3V, so that the DC input signal 608 is 3V.

According to fig. 12, the electronic control device 602 comprises a control unit 610, in particular an ASIC, which can be used to process the audio input signal 604 into an audio output signal 605. For this purpose, the AC input signal 606 of the audio input signal 604 and the DC input signal 608 of the energy source 603 are mainly coordinated to an audio output signal 605.

As mentioned before, the energy source 603 may already have a voltage of 3V, so that the DC input signal 608 is 3V. In this case, the electronic control device 602 is advantageously constructed in such a way that it keeps the DC input signal 608 of the energy source 603 constant, so that the DC output signal 609 corresponds to the DC input signal 608.

The electronic control device 602 may also be constructed in such a way that it attenuates the DC input signal 608 of the energy source 603 so that the DC output signal 609 is smaller than the DC input signal 608. To this end, the electronic control device 602 advantageously comprises a resistor 611 attenuating the DC input signal 608 of the energy source 603, so that the DC output signal 609 is smaller than the DC input signal 608. Wherein the resistor 611 is arranged between the energy source 603 and the control unit 610. Thus, advantageously, the voltage of the DC output signal 609 may be reduced to 0V.

The present invention is not limited to the embodiments shown and described. Variations may be employed which are within the scope of the claims, and features may be combined, even if the features are disclosed and described in different embodiments.

List of reference numerals

1. Audio converter device

2 MEMS audio transducer

30. Diaphragm

31. Reinforcing element

32. Enhanced region

33. Third stop face

34. Middle area

35. Coupling surface

37. Edge region

38. Elastic region

39. Projection

40. Membrane carrier

41. Fastening area

50. Lifting shaft

51. A first direction

52. The second direction

60. Third stopper mechanism

61. First backstop

62. Second stop

70 MEMS unit

71. Carrier substrate

72. End side

73. Converter structure

74. Coupling element

81. Casing body

82. Projection part

83. Casing body

84. Printed circuit board

85 ASIC

86. Groove

87. A first opening

88. Second opening

89. Casing body

90. Cavity body

92. Sound transmission channel

93. Sound inlet/outlet

94. Bottom of the cavity

95. Wall of the cavity

100. First stopper mechanism

101. Coupling element stop

102. First protrusion

103. First mating stop

104. First stop surface

200. Second stopper mechanism

201. Converter structure stop

202. Second protrusion

203. Second mating stop

204. Second stop surface

301. Groove

302. Opening of the container

303. Outer groove

304. Edge section

305. Outer contour

306. Center (C)

307. Inner groove

308. Inner segment

309. Spacer

310. Central groove

311. Projection

312. Shoulder part

313. End of the projection

401. First piezoelectric layer

402. A second piezoelectric layer

403. A first electrode layer

404. A second electrode layer

405. Intermediate layer

406. Support layer

501. Shell body

502. Opening of cavity

503. Protective element

504. First shell layer

505. Second shell layer

601. Electronic unit

602. Electronic control apparatus

603. Energy source

604. Audio input signal

605. Audio output signal

606 AC input signal

607 AC output signal

608 DC input signal

609 DC output signal

610. Control unit

611. A resistor.

Claims

1. An audio transducer device (1),

having a MEMS audio transducer (2) for generating acoustic waves, the MEMS audio transducer (2) having at least one piezoelectric transducer structure (73), and

an electronic unit (601) having the at least one transducer structure (73) for controlling the MEMS audio transducer (2),

the electronic unit (601) comprises an electronic control device (602) and

an energy source (603);

wherein the energy source (603) is electrically connected to the electronic control device (602) and provides a DC input signal (608) to the electronic control device (602);

wherein the electronic control device (602) is configured to process an audio input signal (604) comprising an AC input signal (606) into an audio output signal (605) comprising an AC output signal (607) and a DC output signal (609) and to control the converter structure (73) with the audio output signal (605),

it is characterized in that the preparation method is characterized in that,

the electronic unit (601) is designed in such a way that the converter structure (73) of the MEMS audio converter (2) can be controlled with a DC output signal (609) of less than or equal to 3V.

2. Audio converter device according to claim 1, characterized in that the energy source (603) has a voltage of 3V, such that the DC input signal (608) is 3V.

3. Audio converter device according to claim 1, characterized in that the electronic control device (602) comprises a control unit (610) which is operable to process the audio input signal (604) into the audio output signal (605).

4. Audio converter device according to claim 3, characterized in that the control unit (610) is an ASIC.

5. The audio converter device according to claim 1, characterized in that the electronic control device (602) is constructed to: -keeping a DC input signal (608) of the energy source (603) constant such that the DC output signal (609) corresponds to the DC input signal (608), or

-attenuating a DC input signal (608) of the energy source (603) such that the DC output signal (609) is smaller than the DC input signal (608).

6. Audio converter device according to claim 1, characterized in that the electronic control device (602) comprises a resistor (611) attenuating a DC input signal (608) of the energy source (603), such that the DC output signal (609) is smaller than the DC input signal (608).

7. Audio transducer arrangement according to claim 1, characterized in that the MEMS audio transducer (2) has: a membrane carrier (40) for supporting a membrane,

a membrane (30) which is connected in its edge region (37) to the membrane carrier (40) and can be oscillated along a lifting axis (50) relative to the membrane carrier (40),

and a MEMS unit (70), said MEMS unit (70) comprising at least one transducer structure (73) deflectable along said lifting axis (50) and connected to said membrane (30).

8. Audio converter arrangement according to claim 7, characterized in that the MEMS audio converter (2) comprises a housing (501) and an acoustic cavity (90), wherein the acoustic cavity (90) is built on one side of the membrane (30) and is closed by the housing (501).

9. Audio converter device according to claim 8, characterized in that the acoustic cavity (90) has a cavity opening (502) built into the housing (501) through which air can be exchanged between the acoustic cavity (90) and the environment,

wherein the cavity opening (502) is closed by a gas-permeable porous protective element (503), the porous protective element (503) having an acoustic impedance of 48MKS Rays to 52MKS Rays, and/or a pore size of 34 μm to 38 μm.

10. Audio converter device according to claim 9, characterized in that the porous protective element (503) has an acoustic impedance of 50MKS Rayls.

11. Audio transducer arrangement according to claim 9, characterized in that the porous protective element (503) has a pore size of 36 μm.

12. Audio transducer arrangement according to claim 1, characterized in that the transducer structure (73) comprises at least one piezoelectric layer having a thickness exceeding 1 μm.

13. Audio transducer arrangement according to claim 12, characterized in that the piezoelectric layer has a thickness exceeding 2 μm.

14. Audio transducer arrangement according to claim 7, characterized in that the MEMS audio transducer (2) comprises a coupling element (74), which coupling element (74) is oscillatable together with the membrane (30) along the lifting axis (50) and indirectly connects the membrane (30) with the transducer structure (73).

15. Audio converter device according to claim 7, characterized in that the membrane (30) is flexible and the MEMS audio converter (2) comprises a rigid reinforcement element (31), the reinforcement element (31) being fastened to the membrane (30) and having at least one recess (301).