A microelectromechanical (MEMS) accelerometer has a proof mass and a fixed electrode. The fixed electrode is located relative to the proof mass such that a capacitance formed by the fixed electrode and the proof mass changes in response to a linear acceleration along a sense axis of the accelerometer. The MEMS accelerometer is exposed to heat sources that produce a z-axis thermal gradient in MEMS accelerometer and an in-plane thermal gradient in the X-Y plane of the MEMS accelerometer. The z-axis thermal gradient is sensed with a plurality of thermistors located relative to anchoring regions of a CMOS layer of the MEMS accelerometer. The configuration of the thermistors within the CMOS layer measures the z-axis thermal gradient while rejecting other lateral thermal gradients. Compensation is performed at the accelerometer based on the z-axis thermal gradient.

A circuit for monitoring an output voltage of a hall sensor includes an input port electrically connected to a first hall-sensor output terminal; an output port to output a monitoring voltage; a holder electrically connected to the input port to save the voltage of the input port; a first buffer including a first output terminal and first input terminal having an input impedance higher than an output impedance, having a voltage corresponding to a voltage of the first output terminal, and electrically connected to the holder; a second buffer including a second output terminal and second input terminal having an input impedance higher than an output impedance, having a voltage corresponding to a voltage of the second output terminal, and electrically connected to the input port; and an amplifier producing the monitoring voltage by amplifying a difference in voltages between the first output terminal and the second output terminal.

An apparatus for measuring gravity acceleration of a drilling tool comprises sensors and a measurement circuit. The sensor comprises a three-axis gravity accelerometer, a reference measurement sensor and a temperature sensor. The three-axis gravity accelerometer measures acceleration component signals in three mutually orthogonal directions, and the reference measurement sensor generates a signal that varies with rotation and is not affected by vibration or shock to serve as a reference signal. The temperature sensor measures the temperature in the apparatus to compensate the temperature effect of the gravity accelerometers. The measurement circuit acquires output signals of the sensors and performs cross-correlation processing on the accelerometer components using the reference signal to extract gravity acceleration signals so as to eliminate centrifugal acceleration, vibration, shock and other interferences generated by rotation. The non-interference gravity acceleration signals is used for calculating an inclination angle and a toolface angle of a drilling tool in the rotating state.

An electronic measuring device for measuring a physical parameter includes a differential analogue sensor formed from two capacitances—an excitation circuit of the differential analogue sensor providing to the sensor two electrical excitation signals which are inverted—a measuring circuit which generates an analogue electrical voltage which is a function determined from the value of the sensor, and a circuit for compensating for a possible offset of the sensor, which is formed from a compensation capacitance, which is excited by its own electrical excitation signal. The excitation circuit is arranged in order to be able to provide to an additional capacitance of the compensation circuit its own electrical excitation signal having a linear dependence on the absolute temperature with a determined proportionality factor in order to compensate for a drift in temperature of an electrical assembly of the measuring device comprising at least the compensation capacitance.

A physical quantity sensor device includes a physical quantity sensor and a storage. The storage stores a first constant used as a constant of each term in an approximate polynomial to obtain a first secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a first temperature region less than the first boundary temperature, and a second constant used as a constant of each term in the approximate polynomial to obtain a second secondary frequency temperature characteristic approximated to the actual frequency temperature characteristic, in a second temperature region equal to or greater than the first boundary temperature.

The inertial sensor includes a first substrate provided with an inertial sensor element, and a second substrate. The first substrate includes, in a plan view, a first area to be bonded to the second substrate, a second area which is located outside the first area, and is not bonded to the second substrate, and a third area which is located outside the second area, and is not bonded to the second substrate. The first substrate in the second area has a part thinner than a thickness of the first substrate in the third area.

A microelectromechanical (MEMS) accelerometer has a proof mass and a fixed electrode. The fixed electrode is located relative to the proof mass such that a capacitance formed by the fixed electrode and the proof mass changes in response to a linear acceleration along a sense axis of the accelerometer. The MEMS accelerometer is exposed to heat sources that produce a z-axis thermal gradient in MEMS accelerometer and an in-plane thermal gradient in the X-Y plane of the MEMS accelerometer. The z-axis thermal gradient is sensed with a plurality of thermistors located relative to anchoring regions of a CMOS layer of the MEMS accelerometer. The configuration of the thermistors within the CMOS layer measures the z-axis thermal gradient while rejecting other lateral thermal gradients. Compensation is performed at the accelerometer based on the z-axis thermal gradient.

An inertial measurement unit includes an angular velocity sensor and an acceleration sensor that output inertial information, a storage portion that stores a plurality of correction parameters related to a range of values of the inertial information, a parameter control portion that selects a selection correction parameter from the plurality of correction parameters, and a correction calculation portion that corrects the inertial information using the selection correction parameter.

The present invention relates to microelectromechanical systems (MEMS), and more specifically to an anchor structure for anchoring MEMS components within a MEMS device. The anchor points for rotor and stator components of the device are arranged such that the anchor points are arranged along and overlap a common axis.

A micromechanical sensor. The sensor includes a substrate, a cap element situated on the substrate, at least one seismic mass that is deflectable orthogonal to the cap element, an internal pressure that is lower by a defined amount relative to the surrounding environment prevailing inside a cavity, and a compensating element designed to provide a homogenization of a temperature gradient field in the cavity during operation of the micromechanical sensor.