This disclosure is related to devices, systems, and techniques for determining, using an electro-opto-mechanical accelerometer system, a frequency value in order to determine an acceleration value. For example, an accelerometer system includes a light-emitting device configured to emit an optical signal and a circuit. The circuit is configured to determine a frequency value corresponding to the optical signal and determine an acceleration value based on the frequency value. Additionally, the accelerometer system includes a housing that encloses the light-emitting device, the circuit, and Helium gas, where the Helium gas defines a partial pressure within a range between 0.1 torr and 760 torr.

A method for closed loop operation of a capacitive accelerometer uses a single current source (62) and a single current sink (64) to apply an in-phase drive signal V.sub.1 to a first set of fixed capacitive electrode fingers and a corresponding anti-phase drive signal V.sub.2 to a second set of fixed capacitive electrode fingers. This provides a net electrostatic restoring force on the proof mass for balancing the inertial force of the applied acceleration and maintains the proof mass at a null position.

A method for closed loop operation of a capacitive accelerometer uses a single current source (62) and a single current sink (64) to apply an in-phase drive signal V.sub.1 to a first set of fixed capacitive electrode fingers and a corresponding anti-phase drive signal V.sub.2 to a second set of fixed capacitive electrode fingers. This provides a net electrostatic restoring force on the proof mass for balancing the inertial force of the applied acceleration and maintains the proof mass at a null position.

Provided is a sensor apparatus including: a normal operation unit including a first sensor and a storage device; an external environment detection unit including a second sensor; a power supply switch unit configured to control supply of electric power to the normal operation unit; and a power supply configured to supply the electric power to the normal operation unit via the power supply switch unit. In the sensor apparatus, in an operational mode, the normal operation unit records data measured by the first sensor into the storage device, and, in a non-operational mode, when a measured value obtained by the second sensor satisfies a predetermined condition, the external environment detection unit controls the power supply switch unit so that the power supply switch unit supplies the electric power to the normal operation unit, and the normal operation unit records the data measured by the first sensor into the storage device.

A microelectromechanical system (MEMS) sensor includes a MEMS layer that includes fixed and movable electrodes. In response to an in-plane linear acceleration, the movable electrodes move with respect to the fixed electrodes, and acceleration is determined based on the resulting change in capacitance. A plurality of auxiliary electrodes are located on a substrate of the MEMS sensor and below the MEMS layer, such that a capacitance between the MEMS layer and the auxiliary loads changes in response to an out-of-plane movement of the MEMS layer or a portion thereof. The MEMS sensor compensates for the acceleration value based on the capacitance sensed by the auxiliary electrodes.

A physical quantity sensor includes a substrate, an element portion disposed so as to overlap the substrate, a conductor pattern disposed on the substrate so as to face the element portion, and a protection film covering at least a part of an exposed portion of the conductor pattern exposed from element portion in a plan view from a direction in which the substrate and the element portion overlap.

A MEMS accelerometer includes a suspended spring-mass system that has a frequency response to accelerations experienced over a range of frequencies. The components of the suspended spring-mass system such as the proof masses respond to acceleration in a substantially uniform manner at frequencies that fall within a designed bandwidth for the MEMS accelerometer. Digital compensation circuitry compensates for motion of the proof masses outside of the designed bandwidth, such that the functional bandwidth of the MEMS accelerometer is significantly greater than the designed bandwidth.

A MEMS accelerometer includes a suspended spring-mass system that has a frequency response to accelerations experienced over a range of frequencies. The components of the suspended spring-mass system such as the proof masses respond to acceleration in a substantially uniform manner at frequencies that fall within a designed bandwidth for the MEMS accelerometer. Digital compensation circuitry compensates for motion of the proof masses outside of the designed bandwidth, such that the functional bandwidth of the MEMS accelerometer is significantly greater than the designed bandwidth.

A gyroscope includes an atomic beam source to generate an atomic beam in which individual atoms are in the same state, a moving standing light wave generator to generate M moving standing light waves, an interference device to obtain an atomic beam resulting from the interaction between the atomic beam and the M moving standing light waves, a monitor to detect angular velocity by monitoring the atomic beam from the interference device and an accelerometer. The accelerometer acquires information on acceleration applied to the gyroscope and the moving standing light wave generator adjusts the drift velocity of at least M1 moving standing light waves among the M moving standing light waves in response to the acceleration information.

A gyroscope includes an atomic beam source to generate an atomic beam in which individual atoms are in the same state, a moving standing light wave generator to generate M moving standing light waves, an interference device to obtain an atomic beam resulting from the interaction between the atomic beam and the M moving standing light waves, a monitor to detect angular velocity by monitoring the atomic beam from the interference device and an accelerometer. The accelerometer acquires information on acceleration applied to the gyroscope and the moving standing light wave generator adjusts the drift velocity of at least M1 moving standing light waves among the M moving standing light waves in response to the acceleration information.