Abstract: A capacitive transducer a first part containing a first set of capacitor plates and a second part relatively movable in a plane to the first part. The second part contains a second set of capacitor plates. Both sets of capacitor plates are built on a substrate, wherein the capacitor plates form a plurality of capacitors. The second part is relatively movable in all six degrees of freedom. One set of the plurality of capacitors measures displacements in a plane and a second set of the plurality capacitors measures displacements perpendicular to the plane.

Abstract: A microelectromechanical systems (MEMS) transducer (90) is adapted to sense acceleration in mutually orthogonal directions (92, 94, 96). The MEMS transducer (90) includes a proof mass (100) suspended above a substrate (98) by an anchor system (116). The anchor system (116) pivotally couples the proof mass (100) to the substrate (98) at a rotational axis (132) to enable the proof mass (100) to rotate about the rotational axis (132) in response to acceleration in a direction (96). The proof mass (100) has an opening (112) extending through it. Another proof mass (148) resides in the opening (112), and another anchor system (152) suspends the proof mass (148) above the surface (104) of the substrate (98). The anchor system (152) enables the proof mass (148) to move substantially parallel to the surface (104) of the substrate (98) in response to acceleration in at least another direction (92, 94).

Abstract: An acceleration sensor includes a mount section arranged to be fixed to an object, a flexible section coupled to the mount section, a weight coupled to the mount section via the flexible section, and first and second opposed electrode unit. The first opposed electrode unit includes a first electrode placed on the weight and a second electrode spaced away from and facing the first electrode, and provides a first capacitance. The second opposed electrode unit includes a third electrode placed on the weight and a fourth electrode spaced away from and facing the third electrode, and provides a second capacitance. The first and third electrodes are arranged along a first direction. The second and fourth electrodes are spaced away from and face the first and third electrodes along a second direction perpendicular to the first direction, respectively. A component of an acceleration along the first direction applied to the object is detected based on the first and second capacitances.

Abstract: An insulated accelerometer assembly is provided for attachment to a vibrated component. A base has a portion for engagement and connection with the vibrated component and to transmit vibration. An accelerometer senses vibration and is located at least partially within the base. A housing at least partially encloses the accelerometer and inhibits voltage discharge, corona damage, and voltage tracking on the accelerometer. The housing is made of an insulating material and has an interior for the accelerometer. The housing has a plurality of raised fins on the exterior. A mounting cap also inhibits voltage discharge, corona damage, and voltage tracking and secures the housing. The mounting cap is made of insulating material and has an exterior that includes a plurality of raised fins. A cable has an electrically conductive wire and has a shield to inhibit electrical noise.

Abstract: Microelectromechanical (MEMS) accelerometer and acceleration sensing methods. A MEMS accelerometer includes a proof mass, a planar coil on the proof mass, a magnet, a first pole piece positioned proximate a first side of the proof mass, and a second pole piece positioned proximate a second side of the proof mass. A magnetic flux field passes from the magnet, through the first pole piece, through the planar coil at an angle between approximately 30 degrees and approximately 60 degrees relative to the coil plane, and into the second pole piece. The first pole piece may extend into a first recessed area of a first housing layer and the second pole piece may extend into a second recessed area of a second housing layer. A method includes sensing a capacitance of a pickoff in the MEMS accelerometer and rebalancing the MEMS accelerometer by sending a current through the planar coil.

Abstract: Microelectromechanical (MEMS) accelerometer and acceleration sensing methods. A MEMS accelerometer includes a proof mass suspended by at least one hinge type flexure, at least one planar coil located on the proof mass, and at least one magnet positioned such that a magnetic flux field passes through the at least one planar coil at an angle between approximately 30 degrees and approximately 60 degrees relative to the coil plane. In an example embodiment, the angle is approximately 45 degrees. The at least one magnet may include a first annular magnet positioned on a first side of the poof mass and a second annular magnet positioned on a second side of the proof mass. A method includes sensing a capacitance of a pickoff in the MEMS accelerometer and rebalancing the MEMS accelerometer by sending a current through the planar coil.

Abstract: Microelectromechanical (MEMS) accelerometer and acceleration sensing methods. A MEMS accelerometer includes a housing, a proof mass suspended within the housing by at least one torsional flexure, and a torsional magnetic rebalancing component. In an example embodiment, the torsional magnetic rebalancing component includes at least one planar coil on the proof mass that extends on both sides of an axis of rotation of the proof mass about the at least one torsional flexure and at least one magnet oriented such that a north-south axis of the at least one magnet is oriented approximately orthogonal to the rotational axis of the proof mass. A method includes sensing a change in capacitance of a pickoff in the MEMS accelerometer and rebalancing the MEMS accelerometer by sending a current through the planar coil.

Abstract: A three-axis inertial sensor and a process for its fabrication using an silicon-on-oxide (SOI) wafer as a starting material. The SOI wafer has a first conductive layer separated from a second conductive layer by an insulative buried oxide (BOX) layer. The SOI wafer is fabricated to partially define in its first conductive layer at least portions of proof masses for z, x, and y-axis sensing devices of the sensor. After a conductive deposited layer is deposited and patterned to form a suspension spring for the proof mass of the z-axis sensing device, the SOI wafer is bonded to a substrate that preferably carries interface circuitry for the z, x, and y-axis devices, with the SOI wafer being oriented so that its first conductive layer faces the substrate. Portions of the BOX layer are then etched to fully release the proof masses.

Abstract: A microelectromechanical system (MEMS) includes a housing defining an enclosed cavity, stator tines extending from the housing into the cavity, a MEMS device located within the cavity, the MEMS device including a proof mass and rotor tines extending from the proof mass, each rotor tine being positioned at a capacitive distance from a corresponding stator tine. The rotor tines include a first section extending a first distance from an insulating layer of the rotor tines and a second section extending a second distance from the insulating layer in an opposite direction from the first section. The stator tines include a first section extending a first distance from an insulating layer of the stator tines and a second section extending a second distance from the insulating layer in an opposite direction from the first section, the stator tine first distance being greater than the rotor tine first distance.

Abstract: Substantially hemispherical concave first and second surfaces of substantially equal radius and surface area face each other about a proof mass supported for movement between the surfaces. The surfaces and proof mass have electrically conductive portions allowing assessment of differential capacitance for measurement of acceleration. Electrically conductive portions are connected to a conditioning circuit in an embodiment.

Abstract: The present invention generally relates to systems and methods for determining precision vehicle orientation information. The system includes an inertial measurement unit having a chassis with a first interior surface, an inertial sensor assembly disposed within the chassis and having a first exterior surface, and integrated suspension elements mounted to the first interior surface and the first exterior surface. The integrated suspension elements include a first sensor that senses a displacement measurement of the inertial sensor assembly with respect to the chassis. The displacement measurement is used to determine an angular deflection.

Abstract: A semiconductor mechanical sensor having a new structure in which a S/N ratio is improved. In the central portion of a silicon substrate 1, a recess portion 2 is formed which includes a beam structure. A weight is formed at the tip of the beam, and in the bottom surface of the weight in the bottom surface of the recess portion 2 facing the same, an electrode 5 is formed. An alternating current electric power is applied between the weight portion 4 and the electrode 5 so that static electricity is created and the weight is excited by the static electricity. In an axial direction which is perpendicular to the direction of the excitation of the weight, an electrode 6 is disposed to face one surface of the weight and a wall surface of the substrate which faces the same. A change in a capacitance between the facing electrodes is electrically detected, and therefore, a change in a physical force acting in the same direction is detected.

Abstract: The invention relates to a digital acquisition device for an amplitude modulation signal of a carrier. The acquisition device digitally acquires a useful signal. The useful signal modulates the amplitude of a carrier HF1 which has a frequency and a phase that are known. A modulation of the amplitude of the carrier by the useful signals forms a signal to be processed. According to the invention, the device has a summing device for creating an aggregate signal from a sum of the signal to be processed and a neutralizing signal. The neutralizing signal is a product of the carrier HF1 and of a neutralizing coefficient that can evolve over time, produced by a controlled-gain amplifier device. A load amplifier device amplifies the aggregate signal and produces an amplified aggregate signal. A quadrant comparison device QC is provided for the signal of the amplified aggregate signal and the sign of the carrier which delivers a comparison signal. A sampling device produces a bitstream from the comparison signal.

Abstract: A multi-axis capacitive accelerometer is disclosed. A first mass is disposed and held by an anchor supported by a substrate, wherein the first mass is asymmetrically suspended on the anchor by means of two cantilevers, so that the first mass rotates about a rotation axis, for sensing the acceleration in a first direction perpendicular to the substrate. A second mass is disposed in the first mass and suspended on the first mass by means of a set of springs to sense the acceleration in a second direction parallel to the substrate. Furthermore, a third mass can be disposed in the second mass, wherein the third mass is suspended on the second mass by means of another set of springs to sense the acceleration in a third direction. The first direction, the second direction and the third direction are mutually orthogonal to each other.

Abstract: An acceleration sensor in accordance with an aspect of the present invention comprises a first substrate, a multilayer second substrate and a sensor portion. The multilayer second substrate is opposed to the first substrate. The multilayer second substrate is provided with an electrode drawing opening. Further, the multilayer second substrate consists of a plurality of layers. The sensor portion (a movable mass body and a fixed electrode) is provided in a sealed cavity portion which is formed between the first substrate and the multilayer second substrate which are opposed to each other.

Abstract: A conventional capacitive accelerometer has a limitation in reducing a distance between a sensing electrode and a reference electrode, and requires a complex process and a separate method of correcting a clearance difference caused by a process error. However, the capacitive accelerometer of the present invention has high sensitivity, can be simply manufactured by maintaining a very narrow distance between a reference electrode and a sensing electrode, and can make it unnecessary to individually correct each manufactured accelerometer by removing or drastically reducing a functional difference due to a process error.

Abstract: In a micromachined devices having a movable shuttle driven in oscillation, measuring the electrical charge accumulated on opposing drive capacitors to determine the displacement of the movable shuttle. Alternately, in such a micromachined device, measuring the electrical charge accumulated on a drive capacitor and comparing the measured electrical charge to a nominal electrical charge to determine the displacement of the movable shuttle.

Abstract: One inertial sensor detects an acceleration in a driving direction as well as an angular rate about one axis and an acceleration in a detecting direction at the same time. A driving-direction acceleration detecting unit is provided to members vibrating in mass members on the left and right via an elastic body. In this manner, when an acceleration is applied in the driving direction, the mass members on the left and right normally vibrated with a same amplitude and in opposite phases have displacement amounts in a same phase, and the driving-direction acceleration detecting unit detects the displacement amounts in the same phase as a capacitance change, thereby detecting the acceleration in the driving direction.

Abstract: A weight of an inertial sensor if formed from a plurality of divided weights, and the divided weights are connected to each other by elastically deformable beams. A movable range and a mass of each of the divided weights and a rigidity of each of the beams are adjusted and a plurality of deformation modes having different sensitivity ranges with respect to the acceleration are used in combination. By this means, it is possible to improve a detecting sensitivity of an acceleration and widen an acceleration response range.

Abstract: An acceleration sensor includes a substrate and a first mass element, which is connected to the substrate in such a way that the first mass element is rotatable about an axis, the first mass element being connected to a second mass element in such a way that the second mass element is movable along a first direction parallel to the axis, and the first mass element being connected to a third mass element in such a way that the third mass element is movable along a second direction perpendicular to the axis.

Abstract: Systems and methods sense out-of-plane linear accelerations. In an exemplary embodiment, the out-of plane linear accelerometer is accelerated in an out-of-plane direction, wherein the acceleration generates a rotational torque to an unbalanced proof mass. A rebalancing force is applied to at least one plurality of interleaved rotor comb tines and stator comb tines, wherein the rebalancing force opposes the rotational torque, wherein the rotor comb tines are disposed at an end of the unbalanced proof mass, and wherein the stator comb tines are disposed on a stator adjacent to the end of the unbalanced proof mass. An amount of acceleration is then determined based upon the applied rebalancing force.

Abstract: A micromechanical z-sensor includes a sensitivity, a torsion spring, and a seismic additional mass, the torsion spring having a spring width, and the seismic additional mass including webs having a web width. The web width is selected smaller than the spring width.

Abstract: A micromechanical sensor element includes: a substrate; a first seismic mass suspended from the substrate, which is deflectable from a first rest position by an acceleration acting perpendicularly to a main plane of extension; and a second seismic mass, which is deflectable from a second rest position by the acceleration. At least a partial overlap is provided between the first seismic mass and the second seismic mass perpendicular to the main plane of extension.

Abstract: Provided is an acceleration sensor that has high detection sensitivity and that can enhance production efficiency. The acceleration sensor (50) has: a ceramic substrate (1) made of Al2O3; a ferroelectric layer (2) formed in a predetermined area on the ceramic substrate (1) by screen printing, the ferroelectric layer (2) being made of BaTiO3; a proof mass (4) disposed so as to face the ferroelectric layer (2), the proof mass (4) being formed at a predetermined distance d from the ferroelectric layer (2); and a first electrode (7) and a second electrode (8) that are formed on that side of the proof mass (4) which faces the ferroelectric layer (2), so as to be fixed thereto. The first electrode (7) and the second electrode (8) are each formed in the shape of comb teeth, and comb tooth portions (7a) and (8a) thereof are arranged in an alternating manner.

Abstract: A sensor apparatus includes a sensor circuit and a nonlinear signal processing circuit. The sensor circuit detects a physical quantity and outputs a detection signal indicative of the detected physical quantity. The signal processing circuit includes a logarithmic converter, an analog-to-digital converter, and an antilogarithmic converter. The logarithmic converter produces a logarithm signal corresponding to a logarithm of the detection signal. The analog-to-digital converter digitalizes the logarithm signal. The antilogarithmic converter produces an antilogarithmic signal corresponding to an antilogarithm of the digitalized logarithm signal.

Abstract: A capacitive physical quantity sensor includes a sensor element and a detecting element. The sensor element includes first and second fixed electrodes facing a movable electrode. A first voltage is applied to the first fixed electrode and a second voltage is applied to the second fixed electrode. The detecting circuit includes a capacitance-voltage conversion circuit, in which an operational amplifier, a capacitor and a switch including a P-channel MOS transistor and a N-channel MOS transistor are disposed. The transistors have a back gate potential, which is approximately equal to an average voltage of the first voltage and the second voltage.

Abstract: Provided is a micro-electromechanical-system (MEMS) device including a substrate; at least one semiconductor layer provided on the substrate; a circuit region including at least one chip containing drive/sense circuitry, the circuit region provided on the at least one semiconductor layer; a support structure attached to the substrate; at least one elastic device attached to the support structure; a proof-mass suspended by the at least one elastic device and free to move in at least one of the x-, y-, and z-directions; at least one top electrode provided on the at least one elastic device; and at least one bottom electrode located beneath the at least one elastic device such that an initial capacitance is generated between the at least one top and bottom electrodes, wherein the drive/sense circuitry, proof-mass, supporting structure, and the at least one top and bottom electrodes are fabricated on the at least one semiconductor layer.

Abstract: A micromechanical capacitive acceleration sensor having at least one seismic mass that is connected to a substrate so as to be capable of deflection, at least one electrode connected fixedly to the substrate, and at least one electrode connected to the seismic mass, the at least one electrode connected fixedly to the substrate and the at least one electrode connected to the seismic mass being realized as comb-shaped electrodes having lamellae that run parallel to the direction of deflection of the seismic mass, the lamellae of the two comb-shaped electrodes overlapping partially in the resting state.

Abstract: A MEMS device that has a sensitivity to a stimulus in at least one sensing direction includes a substrate, a movable mass with corner portions suspended in proximity to the substrate, at least one suspension structure coupled approximately to the corner portions of the movable mass for performing a mechanical spring function, and at least one anchor for coupling the substrate to the at least one suspension structure. The at least one anchor is positioned approximately on a center line in the at least one sensing direction.

Abstract: A micromechanical acceleration sensor having a substrate, a suspension, a seismic mass, and stationary capacitive electrodes, in which the seismic mass is suspended over the substrate with the help of the suspension, the seismic mass has a mass center of gravity, the suspension has at least two anchors on the substrate, the two anchors are situated on opposite sides of the mass center of gravity, the distance between the two anchors being small compared to a horizontal extension of the seismic mass, the two anchors determine a central axis, the seismic mass have recesses which are situated on opposite sides of the central axis and are laterally open outward on the sides facing away from the central axis, and the stationary electrodes at least engage in the recesses of the seismic mass.

Abstract: Provided is a vertical acceleration measuring apparatus including a substrate; a plumb that is separated from the substrate to operate; a plurality of movable electrode plates that are formed at an upper end of the plumb in a predetermined direction; a movable electrode plate supporting portion that is formed at the upper end of the plumb and supports the movable electrode plates; a fixed body that is formed at an upper end of the substrate; a fixed electrode plate supporting portion that is coupled to the fixed body adjacent to the upper end of the plumb; a plurality of fixed electrode plates that are supported by the fixed electrode plate supporting portion and arranged to face the movable electrode plates in parallel; and a connection spring that connects the fixed body and the movable electrode plate supporting portion.

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.

Abstract: A MEMS device includes a substrate; a movable mass suspended in proximity to the substrate; and at least one suspension structure coupled to the movable mass for performing a mechanical spring function. The at least one suspension structure has portions that move in tandem when the MEMS device is subject to at least one stimulus in a sensing direction, and further includes at least one link between the portions that move in tandem.

Abstract: A physical quantity sensor includes: a substrate; a movable element; two fixed elements; a carrier wave application element for applying two carrier waves to the fixed elements; a signal application element for applying a middle voltage to the movable element; and a detection circuit for detecting a physical quantity. The detection circuit executes a first self diagnosis process when the signal application element further applies a first self diagnosis signal to the movable element. The first self diagnosis signal has a first frequency for obtaining a resonant magnification equal to or larger than 1.1 times with respect to a resonant frequency of the movable element, so that the movable element is resonated and almost contacts or press contacts one fixed element. The detection circuit determines whether a sticking phenomenon occurs when the signal application element applies the first self diagnosis signal.

Abstract: A microelectromechanical systems (MEMS) sensor (52) includes a substrate (62) a movable element (58) spaced apart from the substrate (62), suspension anchors (66, 68, 70, 72) formed on the substrate (62), and compliant members (74) interconnecting the movable element (58) with the suspension anchors. The MEMS sensor (52) further includes fixed fingers (76) and fixed finger anchors (78) attaching the fixed fingers (76) to the substrate (62). The movable element (58) includes openings (64). At least one of the suspension anchors resides in at least one of the multiple openings (64) and pairs (94) of the fixed fingers (76) reside in other multiple openings (64). The MEMS sensor (52) is symmetrically formed, and a location of the fixed finger anchors (78) defines an anchor region (103) within which the suspension anchors (66, 68, 70, 72) are positioned.

Abstract: A microelectromechanical systems (MEMS) capacitive sensor (52) includes a movable element (56) pivotable about a rotational axis (68) offset between ends (80, 84) thereof. A static conductive layer (58) is spaced away from the movable element (56) and includes electrode elements (62, 64). The movable element (56) includes a section (74) between the rotational axis (68) and one end (80) that exhibits a length (78). The movable element (56) further includes a section (76) between the rotational axis (68) and the other end (84) that exhibits a length (82) that is less than the length (78) of the section (74). The section (74) includes slots (88) extending through movable element (56) from the end (80) toward the rotational axis (68). The slots (88) provide stress relief in section (74) that compensates for package stress to improve sensor performance.

Abstract: First and second detection frames are supported by a substrate to be rotatable about first and second torsion axes. A first link beam is connected to the first detection frame on an axis located at a position moved from a position of the first torsion axis in a first direction crossing the first torsion axis and directed to one end side of the first detection frame. A second link beam is connected to the second detection frame on an axis located at a position shifted from a position of the second torsion axis in a second direction opposite to the first direction. An inertia mass body is displaceable in a thickness direction of the substrate by being linked with the first and second detection frames by the first and second link beams, respectively. This constitution makes it possible to obtain a highly precise acceleration sensor hardly influenced by disturbances.

Abstract: When the mode is switched to a motion detection mode, using a changeover switch, the mode is switched to the motion detection mode by pressing the changeover switch. In this mode, motion detection is performed by moving a hand in an area to be operated. When the mode is switched from the motion detection mode to a normal mode, the hand is moved away from the area to be operated, or the changeover switch is again pressed. Moreover, when the hand is distant from a capacitive sensor, it is determined that a motion input operation is being performed. When the hand is close to the capacitive sensor, it is determined that no motion input operation is being performed, and thus the motion detection mode is changed.

Abstract: A micromechanical acceleration sensor has a substrate, a suspension, a seismic mass, and stationary capacitive electrodes, which seismic mass is suspended over the substrate with the aid of the suspension. The seismic mass has a mass center of gravity, and the suspension has at least two anchors on the substrate, the at least two anchors being situated next to the mass center of gravity at a distance which is small compared to a horizontal extension of the seismic mass. The stationary capacitive electrodes are provided in recesses of the seismic mass. The seismic mass directly surrounds the suspension.

Abstract: An accelerometer is fabricated as a MEMS device and includes an array of capacitive electrode plates mechanically coupled to a common proof mass. The proof mass is constrained to move or vibrate in the plane parallel to the first array of plates. The capacitance between the first array of plates is measured with respect to additional arrays of capacitive plates inter-digitated in a comb like pattern.

Abstract: According to the present invention, an in-plane sensor comprises: a fixed structure including a fixed finger and a fixed column connected to each other, the fixed finger having a supported end supported by the fixed column and a suspended end which is unsupported; and a movable structure including at least one mass body and an extending finger connected to each other; wherein the supported end of the fixed finger is closer to the mass body than the suspended end is.

Abstract: System and method for mitigating errors in electrostatic force balanced instrument is provided. The system and method mitigate errors in measurement readings caused by charge buildup in force balanced instruments that employ charge pulses to generate an electrostatic force to null an inertial proof mass disposed between opposing electrodes. The system and method mitigate charge buildup by applying charge pulses to each opposing electrode of a sensing element for a given charge cycle time period in a normal polarity configuration followed by charge pulses to each opposing electrode of the sensing element for a second given charge cycle time period in a reverse polarity configuration.

Abstract: A differential capacitive sensor (50) includes a movable element (56) pivotable about a rotational axis (60). The movable element (56) includes first and second sections (94, 96). The first section (94) has an extended portion (98) distal from the rotational axis (60). A static layer (52) is spaced away from a first surface (104) of the moveable element (56), and includes a first actuation electrode (74), a first sensing electrode (64), and a third sensing electrode (66). A static layer (62) is spaced away from a second surface (106) of the moveable element (56) and includes a second actuation electrode (74), a second sensing electrode (70), and a fourth sensing electrode (72). The first and second electrodes (64, 70) oppose the first section (94), the third and fourth electrodes (66, 72) oppose the second section (96), and the first and second electrodes (68, 74) oppose the extended portion (98).

Abstract: A capacitive sensor includes a fixed electrode and a movable electrode that is movably supported by an anchor portion through a beam portion. The fixed electrode and the movable electrode are opposed to each other with a gap interposed therebetween, thereby constituting a detecting unit. A capacitance suitable for a size of the gap is detected to detect a predetermined physical value. At least one of an end of the beam portion connected to the anchor portion and an end of the beam portion connected to the movable electrode is provided with a stress moderating unit that moderates a stress.

Abstract: The invention relates to accelerometer structures micro-machined according to micro-electronics technologies. The accelerometer according to the invention comprises a substrate, an elastically deformable thin-layer membrane suspended above the substrate and secured to the substrate at its periphery, a proof mass suspended above the membrane and linked to the latter by a central stud, and capacitive interdigitated combs distributed about the mass, having movable plates secured to the mass and fixed plates secured to the substrate. The fixed plates and movable plates of the various combs are of differentiated heights to help in the discrimination of the upward and downward vertical accelerations.

Abstract: The acceleration sensor package comprises an acceleration sensor chip having a pad forming surface formed with a plurality of pads at at least one edge portion, a control chip having a terminal forming surface formed with connecting terminals, and a case body having a storage concave section for accommodating the acceleration sensor chip and the control chip therein and bottom face terminals respectively disposed at positions corresponding to the pads at a bottom face of the storage concave section. The pads of the acceleration sensor chip are respectively electrically connected to the bottom face terminals of the case body. A back surface located on the side opposite to the terminal forming surface, of the control chip is mated with its corresponding back surface located on the side of the pad forming surface, of the acceleration sensor chip.

Abstract: Micromachined accelerometer and method in which a proof mass is suspended above a substrate for movement in response to acceleration, electrodes form capacitors which change in capacitance in response to movement of the proof mass, processing circuitry responsive to the changes in capacitance provides an output signal corresponding to movement of the proof mass, a test signal is applied to the electrodes during use of the accelerometer to produce additional movement of the proof mass and a corresponding test signal component in the output signal, and the output signal is monitored to determine whether the accelerometer is operating normally by the presence of the test signal component in the output signal.

Abstract: A MEMS piezoelectric sensor comprises a plurality of capacitors some of which may be used for sensing and others used for feedback. The capacitors may be switched to connect or disconnect selected capacitors from the sensor. Embodiments convert a two port sensor into a four port sensor without significant changes in hardware design and improve SNR and correct for offset and out-of-axis errors due to process mismatch and variations.

Abstract: A single crystal silicon substrate (1) is bonded through an SiO2 film (9) to a single crystal silicon substrate (8), and the single crystal silicon substrate (1) is made into a thin film. A cantilever (13) is formed on the single crystal silicon substrate (1), and the thickness of the cantilever (13) in a direction parallel to the surface of the single crystal silicon substrate (1) is made smaller than the thickness of the cantilever in the direction of the depth of the single crystal silicon substrate (1), and movable in a direction parallel to the substrate surface. In addition, the surface of the cantilever (13) and the part of the single crystal silicon substrate (1), opposing the cantilever (13), are, respectively, coated with an SiO2 film (5), so that an electrode short circuit is prevented in a capacity-type sensor. In addition, a signal-processing circuit (10) is formed on the single crystal silicon substrate (1), so that signal processing is performed as the cantilever (13) moves.

Abstract: A single crystal silicon substrate (1) is bonded through an SiO2 film (9) to a single crystal silicon substrate (8), and the single crystal silicon substrate (1) is made into a thin film. A cantilever (13) is formed on the single crystal silicon substrate (1), and the thickness of the cantilever (13) in a direction parallel to the surface of the single crystal silicon substrate (1) is made smaller than the thickness of the cantilever in the direction of the depth of the single crystal silicon substrate (1), and movable in a direction parallel to the substrate surface. In addition, the surface of the cantilever (13) and the part of the single crystal silicon substrate (1), opposing the cantilever (13), are, respectively, coated with an SiO2 film (5), so that an electrode short circuit is prevented in a capacity-type sensor. In addition, a signal-processing circuit (10) is formed on the single crystal silicon substrate (1), so that signal processing is performed as the cantilever (13) moves.