Invensense, Inc.

Advanced Micro Devices Corporation

National Semiconductor Corporation

Vadim M Tsinker

Matthew Julian Thompson

Jongwoo Shin

Houri Johari-Galle

Sarah Nitzan

Logeeswaran Veerayah Jayaraman

David deKoninck

Varun Subramaniam Kumar

Le Jin

Sriraman Dakshinamurthy

Ilya Gurin

Stanley Bo-Ting Wang

Du Chen

Federico Mazzarella

Simon M Bikulcius

Ali Shirvani

Frederico Mazzarella

In a microelectromechanical system (MEMS) sensor, movement of a component such as a proof mass due to a force of interest is sensed capacitively. A capacitance-to-voltage (C2V) converter receives a capacitance signal from the sensor and outputs a signal that includes an offset in addition to a signal of interest. The output signal is analyzed to identify the offset portion of the output signal and to modify values one or more variable capacitors coupled to the C2V input reduce the offset portion of the output signal.

Dynamic capacitance-to-volvage offset cancellation

A round robin sensor device for processing sensor data is provided herein. The sensor device includes a multiplexer stage configured to sequentially select sensor outputs from one or more sensors continuously. Continuously and sequentially selecting sensor outputs results in a stream of selected sensor outputs. The sensor device also includes a charge-to-voltage converter operatively coupled to the multiplexer stage and configured to convert a charge from a first sensor of the one or more sensors to a voltage. Further, the sensor device includes a resettable integrator operatively coupled to the charge-to-voltage converter and configured to demodulate and integrate the voltage, resulting in an integrated voltage. Also included in the sensor device is an analog-to-digital converter operatively coupled to the resettable integrator and configured to digitize the integrated voltage to a digital code.

Round robin sensor device for processing sensor data

An exemplary microelectromechanical device includes a MEMS layer, portions of which respond to an external force in order to measure the external force. A substrate layer is located below the MEMS layer and an anchor couples the substrate layer and MEMS layer to each other. A plurality of temperature sensors are located within the substrate layer to identify a temperature gradient being experienced by the MEMS device. Compensation is performed or operations of the MEMS device are modified based on temperature gradient.

Systems and methods for operating a mems device based on sensed temperature gradients

Systems and methods for operating a MEMS device based on sensed temperature gradients

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.

High performance accelerometer

A method of measuring noise of an accelerometer can comprise exposing the accelerometer comprising a micro-electro-mechanical system (MEMS) component coupled to an application specific integrated circuit component (ASIC), to an external environmental input, with the MEMS component being configured to provide a first output to the ASIC based on the external environmental input. The method can further comprise estimating a first noise generated by operation of the MEMS component, and replacing the first output provided to the ASIC from the MEMS component, with a second output generated by a MEMS emulator component, with the second output comprising the first noise. Further, the method can include generating an output of the accelerometer based on the second output processed by the ASIC.

Measuring a noise level of an accelerometer

A microelectromechanical (MEMS) device may be coupled to a dielectric material at an upper planar surface or lower planar surface of the MEMS device. One or more temperature sensors may be attached to the dielectric material layer. Signals from the one or more temperature sensors may be used to determine a thermal gradient along on axis that is normal to the upper planar surface and the lower planar surface. The thermal gradient may be used to compensate for values measured by the MEMS device.

Package level thermal gradient sensing

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.

Vertical thermal gradient compensation in a z-axis MEMS accelerometer

Facilitating a reduction in sensor system latency, circuit size, and current draw utilizing a group of continuous-time Nyquist rate analog-to-digital converters (ADCs) in a round-robin manner is presented herein. A sensor system can comprise a group of sensors that generate respective sensor output signals based on an external excitation of the sensor system; a multiplexer that facilitates a selection, based on a sensor selection input, of a sensor output signal of the respective sensor output signals corresponding to a sensor of the group of sensors; a sense amplifier comprising a charge or voltage sensing circuit that converts the sensor output signal to an analog output signal; and a continuous-time Nyquist rate analog-to-digital converter of the group of continuous-time Nyquist rate ADCs that converts the analog output signal to a digital output signal representing at least a portion of the external excitation of the sensor system.

Sensing an external stimulus using a group of continuous-time Nyquist rate analog-to-digital converters in a round-robin manner

A system includes a sensor device, a circuit driving he sensor device at a drive frequency, a receiver, and a low pass filter. The sensor device is configured to change its electrical characteristics in response to external stimuli. The sensor device generates a modulated signal proportional to the external stimuli. The receiver is configured to receive the modulated signal and further configured to demodulate the modulated signal to generate a demodulated signal. The demodulation signal has a guard band. The receiver consumes power responsive to receiving the modulated signal. The low pass filter is configured to receive the demodulated signal and further configured to generate a sensor output.

Continuous-time sensing apparatus

Reducing noise from drive tone and sense resonance peaks of a micro-electro-mechanical system (MEMS) gyroscope output using a notch filter is presented herein. The MEMS gyroscope can include a drive oscillation component configured to vibrate a sensor mass at a drive resonance frequency; a sense circuit configured to detect a deflection of the sensor mass, and generate, based on the deflection and the drive resonance frequency, a demodulated output; and a signal processing component configured to receive a set of frequencies comprising a first value representing the drive resonance frequency and a second value corresponding to a sense resonance frequency associated with the sense circuit, and apply, based on the first value and the second value, a notch filter to the demodulated output to obtain a filtered output.

Reducing resonance peaks and drive tones from a micro-electro-mechanical system gyroscope response

A MEMS device and method for amplitude regulation of a MEMS device are disclosed. In a first aspect, the MEMS device comprises a MEMS resonator, a limiter coupled to the MEMS resonator, and a regulator coupled to the limiter. The MEMS device includes an amplitude control circuit coupled to the MEMS resonator. The amplitude control circuit controls a supply of the limiter via the regulator to regulate oscillation loop amplitude of the MEMS device. In a second aspect, the method includes coupling a regulator to the limiter, coupling an amplitude control circuit to the MEMS resonator, and controlling a supply of the limiter via the regulator to regulate oscillation loop amplitude of the MEMS device.

MEMS device oscillator loop with amplitude control

A testing device for testing a high-speed serial transmitter or other device includes an input stage having a first comparator, a second comparator, and a digital-to-analog converter. The first comparator compares first differential signals from a device under test. The second comparator compares the first differential signals and second differential signals from the digital-to-analog converter. An analysis unit identifies first beats based on an output of the first comparator and second beats based on an output of the second comparator. The analysis unit identifies one or more characteristics of the device under test (such as jitter, differential signal swing, and transition time) based on the first and second beats. A clock unit provides an adjustable clock signal to the comparators. The clock signal may have a frequency shift with respect to a frequency of the device under test.

Apparatus and method for testing high-speed serial transmitters and other devices

An integrated circuit in accordance with one embodiment of the invention includes an oscillator circuit and a source circuit. The source circuit outputs a reference voltage and a bias current, wherein the reference voltage changes by substantially the same proportion as the bias current. The oscillator circuit is coupled to receive the reference voltage and the bias current from the source circuit. The oscillator circuit outputs an oscillating electrical signal.

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Belmont, CA, United States of America

Vadim M Tsinker