Invensense, Inc.

Panasonic Corporation

Omid Oliaei

Baris Cagdaser

Martin Lim

Julius Ming-Lin Tsai

Peter George Hartwell

Xiang Li

Adolfo Giambastiani

Behrad Aria

Aleksey Sergeyevich Khenkin

Fariborz Assaderaghi

Renata Melamud Berger

Stephen F Bart

Daniele Ottini

Aurelio Pellegrini

Mehran Ayat

A circuit for a feedback system incorporates a gating mechanism to reduce flicker noise (e.g., a source for bias instability within a MEMS device) at a digital output. The gating mechanism generates a gating pulse with a delay period (e.g., a common, or fixed, delay including symmetrical rising and falling edge delays) that overrides internal delays (e.g., asymmetrical rising and falling edge delays) of a phase generator to prevent propagation delay (e.g., delay affected by jitter) from reaching subsequent feedback components (e.g., a digital-to-analog converter (DAC)) and contributing to the generation of flicker noise within the system.

Clocking scheme for reduced noise in continuous-time sigma-delta adcs preliminary class

The present invention relates to an incremental analog to digital converter incorporating noise shaping and residual error quantization. In one embodiment, a circuit includes an incremental analog to digital converter, comprising a loop filter that filters an analog input signal in response to receiving a reset signal, resulting in a filtered analog input signal, and a successive approximation register (SAR) quantizer, coupled with the filtered analog input signal, that converts the filtered analog input signal to an intermediate digitized output of a first resolution based on a reference voltage, wherein the SAR quantizer comprises a feedback loop that shapes quantization noise generated by the SAR quantizer as a result of converting the filtered analog input signal; and a digital filter, coupled with the intermediate digitized output, that generates a digitized output signal of a second resolution, greater than the first resolution, by digitally filtering the intermediate digitized output.

Incremental analog to digital converter incorporating noise shaping and residual error quantization

A microelectromechanical (MEMS) sensor has a capacitance that varies based on a sensed force. A charge signal representing that capacitance is provide at an input node of an amplifier of a sense circuit. The sense circuit includes a filter and analog-to-digital converter. Feedback from the filter and the analog-to-digital converter is also received at the input node of the amplifier. The sense circuit outputs a digital signal that is representative of the sensed force.

Method and device for band-pass sensor data acquisition

Facilitating fault detection of a system using a test input including a linear combination of inputs of the system is presented herein. A test signal component generates, via a test procedure, a test input signal including a first linear combination of at least two input signals of the system, and applies the test input signal to the system during a phase of respective phases of the test procedure; and a fault detection component detects a fault of the system based on a test output signal corresponding to the test input signal and a second linear combination of respective output signals of the system corresponding to the at least two input signals.

Fault detection of a system using a test input comprising a linear combination of inputs of the system

A modulator system for converting a current-varying sensor output to a digital representation is disclosed. The modulator system includes a resonator with a first resonator input and a second resonator input. The first resonator input carries a constant reference current and the second resonator input carries a varying input current. In response to a digital output, the resonator generates a complementary voltage output based on a difference between the constant reference current and the varying input current during a conversion time. The resonator resonates near or at zero frequency. An accumulated digital output is based on the accumulation of the digital output generated at each sampling clock cycle of the conversion time and represents a digital word proportional to the varying input current.

Low-power high-precision sensing circuit

A fault detection system on a circuit can detect a fault on the same circuit without using a duplicate circuit. A test signal can be generated based on an input signal, and the input signal and test signal can be sent through the circuit and the resulting signals can be compared to determine if any fault is present. In an embodiment, a function can be applied to bits of the input signal and bits of the test signal such that when the signals are compared after passing through the processing block that is to be tested, if the variation between the signals is above a predetermined amount, it can be determined that a fault has occurred. In other embodiments, a first function can be applied to the input signal, and a second function can be applied to the test signal, and the resulting outputs can be compared.

Single circuit fault detection

Acoustic ambient temperature and humidity sensing based on determination of sound velocity is described, in addition to sensors, algorithms, devices, systems, and methods therefor. An exemplary embodiment employs sound velocity in the determination of ambient temperature and humidity. Provided implementations include determinations of sound velocity based on time of flight of a coded acoustic signal and/or based on resonance frequency of a Helmholtz resonator.

Acoustic ambient temperature and humidity sensing

Multi-path signal processing for microelectromechanical systems (MEMS) sensors is described. An exemplary MEMS sensor apparatus can comprise a single MEMS sensor element and an associated integrated circuit (IC) that facilitates generating multiple output signals having different output signal electrical characteristics required by a host system. Provided implementations can minimize cost and IC die area of associated MEMS sensor apparatuses and systems by employing one or more signal multiplexers (MUXs) on a single common signal path from the single MEMS sensor element. In addition, various methods of generating multiple output signals having different output signal electrical characteristics from a single MEMS sensor element are described.

Multi-path signal processing for microelectromechanical systems (MEMS) sensors

Detection of audible and ultrasonic signals is provided by a microelectromechanical microphone. The detection range of ultrasonic signals can be configurable. In certain embodiments, the microelectromechanical microphone can include a band-pass sigma-delta modulator that can generate a digital signal representative of an ultrasonic signal. In addition or in other embodiments, the microelectromechanical microphone can include an event detector device that can determine that an ultrasonic event has occurred and, in response, can send a control signal to an external device. Detection of ultrasonic signals can be utilized in vehicular applications and/or gesture recognition.

Ultrasonic operation of a digital microphone

Providing security features in an audio sensor is presented herein. A micro-electro-mechanical system (MEMS) microphone can include an acoustic membrane that converts an acoustic signal into an electrical signal; an electronic amplifier that increases an amplitude of the electrical signal to generate an amplified signal; and switch(es) configured to prevent propagation of a direct current (DC) voltage source to the MEMS microphone; prevent propagation of the DC voltage source to the electronic amplifier; prevent propagation of the electrical signal to the electronic amplifier; and/or prevent propagation of the amplified signal to an external device.

Secure audio sensor

Microelectromechanical systems (MEMS) acoustic sensors are implemented with dedicated preamplifiers. Provided implementations can comprise an array of MEMS acoustic sensor elements each having a dedicated preamplifier. A summation node can add outputs of each preamplifier and an analog to digital converter (ADC) can receive the summed outputs. Other implementations can comprise an array of MEMS acoustic sensors each having dedicated preamplifiers. Some of the preamplifiers receive an invert signal and an ADC can subtract inverted signals from non-inverted signals.

Microelectromechanical systems (MEMS) microphone array with dedicated amplifiers

Systems and techniques for detecting blockage associated with a microelectromechanical systems (MEMS) microphone of a device are presented. The device includes a MEMS acoustic sensor and a processor. The MEMS acoustic sensor is contained in a cavity within the device. The processor is configured to detect a blockage condition associated with an opening of the cavity that contains the MEMS acoustic sensor.

Blockage detection for a microelectromechanical systems sensor

A programmable acoustic sensor is disclosed. The programmable acoustic sensor includes a MEMS transducer and a programmable circuitry coupled to the MEMS transducer. The programmable circuitry includes a power pin and a ground pin. The programmable acoustic sensor also includes a communication channel enabling data exchange between the programmable circuitry and a host system. One of the power pin and the ground pin can be utilized for data exchange.

Multi-function pins for a programmable acoustic sensor

A microphone device comprising a microelectromechanical systems (MEMS) acoustic sensors, an automatic gain compensation (AGC) component, and a direct current (DC) offset cancellation component is described. An microphone device can be configured for AGC of an analog gain stage or a digital gain stage associated with the MEMS acoustic sensor. Provided implementations can also be configured to compensate DC offset resulting from adjustment of the analog provided by the AGC component. Additional embodiments of the subject disclosure can provide digital frequency equalization and/or linearization.

Growing community of inventors

Sunnyvale, CA, United States of America

Omid Oliaei