Abstract: A gas sensor includes a plurality of sensing resistors that vary in resistance based on ambient temperature and the presence of certain gases, such as CO2 and H2O. The responses of each of the sensing resistors vary based on a base temperature of each of the sensing resistors. The base temperatures for each of the sensing resistors and configurations of the sensing resistors are selected to emphasize a response to a gas of interest (e.g., CO2) while de-emphasizing or canceling contributions from ambient temperature and gases that are not of interest (e.g., H2O).

Abstract: A microelectromechanical system (MEMS) test structure includes a plurality of capacitors formed from sense electrodes and capacitive plates having a predetermined geometry and size associated with a related MEMS device such as a MEMS sensor. Based on the predetermined relationships between the capacitors of the test structure, and between the test structure and the MEMS devices, an effect of fringing fields on the sensed capacitances of the MEMS devices may be eliminated, and the capacitive gap of the MEMS device may be accurately measured.

Abstract: An alternate venting path can be employed in a sensor device for pressure equalization. A sensor component of the device can comprise a diaphragm component and/or backplate component disposed over an acoustic port of the device. The diaphragm component can be formed with no holes to prevent liquid or particles from entering a back cavity of the device, or gap between the diaphragm component and backplate component. A venting port can be formed in the device to create an alternate venting path to the back cavity for pressure equalization for the diaphragm component. A venting component, comprising a filter, membrane, and/or hydrophobic coating, can be associated with the venting port to inhibit liquid and particles from entering the back cavity via the venting port, without degrading performance of the device. The venting component can be designed to achieve a desired low frequency corner of the sensor frequency response.

Abstract: A robotic cleaning appliance includes a sonic transducer and a processor coupled with a housing. The sonic transducer transmits sonic signals toward a surface within its ringdown distance and receives corresponding returned signals. Following cessation of the sonic signals, the processor samples the ringdown signal generated by the sonic transducer during an early portion before the corresponding returned signals have reflected back to the sonic transducer, and during a later portion which includes the corresponding returned signals. The processor utilizes the sampled early portion to estimate a void ringdown signal of which represents performance of the sonic transducer in absence of returned signals being received. The processor compares the estimated void ringdown signal to the later portion of the ringdown signal and generates a metric based on the comparison. The processor utilizes the metric to determine a type of the surface, out of a plurality of surface types.

Abstract: In a method of automatic alignment of a transversal ultrasound array, a plurality of instances of an ultrasonic scanning operation directed towards a target using an array of ultrasonic transducers is performed, wherein each instance of the plurality of instances of the ultrasonic scanning operation comprises a different sub-array of ultrasonic transducers of the array of ultrasonic transducers, and wherein each instance of the ultrasonic scanning operation transmits an ultrasonic signal and receives at least one reflected ultrasonic signal. At least one property is determined for each of the at least one reflected ultrasonic signal of each instance of the ultrasonic scanning operation. An ultrasonic transducer of the array of ultrasonic transducers is selected as exhibiting alignment with the target based at least in part on the at least one property for each of the at least one reflected ultrasonic signal of each instance of the ultrasonic scanning operation.

Abstract: A wearable system for cardiovascular monitoring including an ultrasonic sensor module, a data storage unit, a processing unit, and a connection cable assembly for communicatively coupling the ultrasonic sensor module to the processing unit is described. The ultrasonic sensor module includes at least one array of ultrasonic transducers and at least one pre-amplification device coupled to the at least one array of ultrasonic transducers, the ultrasonic sensor module for placement on a human body proximate a blood vessel for performing cardiovascular monitoring.

Abstract: An ultrasonic sensing system including a plurality of ultrasonic transducers for placement on a human body proximate a blood vessel, a hardware controller for controlling operation of the plurality of ultrasonic transducers, and a digital processing module for processing the reflected ultrasonic signals. The plurality of ultrasonic transducers includes a first subset of ultrasonic transducers, wherein the ultrasonic transducers of the first subset are arranged linearly and a second subset of ultrasonic transducers, wherein the ultrasonic transducers of the second subset are arranged linearly, wherein the first subset of ultrasonic transducers is positioned parallel to the second subset of ultrasonic transducers at a fixed separation distance.

Abstract: In a method for operating a fingerprint sensor including a plurality of ultrasonic transducers, receiving a plurality of images corresponding to different subsets of the ultrasonic transducers of the fingerprint sensor are received, wherein the plurality of images are non-adjacent. For each image of the plurality of images, it is determined whether the image of the plurality of images is indicative of a fingerprint. Provided a number of images of the plurality of images that are indicative of a fingerprint satisfies a threshold, it is determined whether the images of the plurality of images that are indicative of a fingerprint are collectively indicative of a fingerprint. Provided the plurality of images are collectively indicative of a fingerprint, it is determined that the plurality of images include a fingerprint.

Abstract: 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.

Abstract: An audio activity detector device is disclosed. The audio activity detector device comprises a closed loop feedback regulating circuit that supplies an input signal representative of a time-varying voltage signal to a quantizer circuit, wherein the quantizer circuit, as a function of the input signal, converts the input signal to a quantizer discrete-time signal; a first circuit that, as a function of the discrete-time signal, determines a key quantizer statistic value for the quantizer discrete-time signal; and a second circuit that, as a function of the key quantizer statistic value, determines a signal statistic value for the input signal and a gain control value.

Abstract: A modification to rough polysilicon using ion implantation and silicide is provided herein. A method can comprise depositing a hard mask on a single crystal silicon, patterning the hard mask, and depositing metal on the single crystal silicon. The method also can comprise forming silicide based on causing the metal to react with exposed silicon of the single crystal silicon. Further, the method can comprise removing unreacted metal and stripping the hard mask from the single crystal silicon. Another method can comprise forming a MEMS layer based on fusion bonding a handle MEMS with a device layer. The method also can comprise implanting rough polysilicon on the device layer. Implanting the rough polysilicon can comprise performing ion implantation of the rough polysilicon. Further, the method can comprise performing high temperature annealing. The high temperature can comprise a temperature in a range between around 700 and 1100 degrees Celsius.

Abstract: Systems and methods are provided that provide a getter in a micromechanical system. In some embodiments, a microelectromechanical system (MEMS) is bonded to a substrate. The MEMS and the substrate have a first cavity and a second cavity therebetween. A first getter is provided on the substrate in the first cavity and integrated with an electrode. A second getter is provided in the first cavity over a passivation layer on the substrate. In some embodiments, the first cavity is a gyroscope cavity, and the second cavity is an accelerometer cavity.

Abstract: The teachings of the present disclosure enable the manufacture of one or more piezoelectric micromachined ultrasonic transducers (PMUTs) having a resonant frequency of a specific target value and/or substantially matched resonant frequencies. In accordance with the present disclosure, a flexible membrane of a PMUT is modified to impart a desired parameter profile for stiffness and/or mass to tune its resonant frequency to a target value. The desired parameter profile is achieved by locally removing or adding material to regions of one or more layers of the flexible membrane to alter its geometric dimensions and/or density. In some embodiments, material is added or removed non-uniformly across the structural layer to realize a material distribution that more strongly affects membrane stiffness than mass. In some embodiments, material having a specific residual stress is added to, and/or removed from, the membrane to define a desired modal stiffness for the membrane.

Abstract: The described technology is generally directed towards a sensor output digitizer. The sensor output digitizer can comprise a multiplexer stage, a multi-stage analog to digital converter, and a digital output combiner. The multiplexer stage can be configured to sequentially select sensor outputs from one or more sensors, resulting in a stream of selected sensor outputs. The multi-stage analog to digital converter can be coupled with the multiplexer stage, and can be configured to convert the stream of selected sensor outputs into a stream of digitized outputs. The digital output combiner can be configured to re-scale and sum intermediate outputs of the multi-stage analog to digital converter to produce a stream of digitized sensor outputs.

Abstract: A hardware-programmable digital signal path component for processing events from sensor mixed signal devices. A system includes a mixed signal component and a reconfigurable signal path component. The mixed signal component includes a group of sensor devices and generates one or more events from among the group of sensor devices. The signal path component receives the event(s), and includes a control unit component and a digital signal processor (DSP) component. The control unit component includes a programmable function enable mechanism, and distributes the received event(s) in combination with one or more functions among a set of predefined functions enabled by the programmable function enable mechanism. The DSP component is configured to perform one or more operations associated with the distributed event(s) in accordance with the enabled function(s).

Abstract: A method includes fusion bonding a handle wafer to a first side of a device wafer. The method further includes depositing a first mask on a second side of the device wafer, wherein the second side is planar. A plurality of dimple features is formed on an exposed portion on the second side of the device wafer. The first mask is removed from the second side of the device wafer. A second mask is deposited on the second side of the device wafer that corresponds to a standoff. An exposed portion on the second side of the device wafer is etched to form the standoff. The second mask is removed. A rough polysilicon layer is deposited on the second side of the device wafer. A eutectic bond layer is deposited on the standoff. In some embodiments, a micro-electro-mechanical system (MEMS) device pattern is etched into the device wafer.

Abstract: 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.

Abstract: An ultrasonic transducer device comprises a piezoelectric micromachined ultrasonic transducer (PMUT), a transmitter with first and second differential outputs, and a controller. The PMUT includes a membrane layer. A bottom electrode layer, comprising a first bottom electrode and a second bottom electrode, is disposed above the membrane layer. The piezoelectric layer is disposed above the bottom electrode layer. The top electrode layer is disposed above the piezoelectric layer and comprises a segmented center electrode disposed above a center of the membrane layer and a segmented outer electrode spaced apart from the segmented center electrode. The controller, responsive to the PMUT being placed in a transmit mode, is configured to couple the first and second segments of the bottom electrode layer with ground, couple the first output of the transmitter with the segments of the segmented center electrode, and couple the second output with the segments of the segmented outer electrode.

Abstract: A method includes tab dicing a region of a tab region disposed between a first die and a second die. The tab region structurally connects the first die to the second die each including a MEMS device eutecticly bonded to a CMOS device. The tab region includes a handle wafer layer disposed over a fusion bond oxide layer that is disposed on an ACT layer. The tab region is positioned above a CMOS tab region that with the first and second die form a cavity therein. The tab dicing cuts through the handle wafer layer and leaves a portion of the fusion bond oxide layer underneath the handle wafer layer to form an oxide tether within the tab region. The oxide tether maintains the tab region in place and above the CMOS tab region. Subsequent to the tab dicing the first region, the tab region is removed.

Abstract: Disclosed embodiments provide glitch prediction based on machine learning algorithms in mixed analog and digital systems, particularly directed to digital microelectromechanical (MEMS) multipath acoustic sensors or microphones, which allow seamless, low latency gain changes without audible artifacts or interruptions in the audio output signal.