Abstract: Microelectromechanical system (MEMS) inertial sensors exhibiting reduced parasitic capacitance are described. The reduction in the parasitic capacitance may be achieved by forming localized regions of thick dielectric material. These localized regions may be formed inside trenches. Formation of trenches enables an increase in the vertical separation between a sense capacitor and the substrate, thereby reducing the parasitic capacitance in this region. The stationary electrode of the sense capacitor may be placed between the proof mass and the trench. The trench may be filled with a dielectric material. Part of the trench may be filled with air, in some circumstances, thereby further reducing the parasitic capacitance. These MEMS inertial sensors may serve, among other types of inertial sensors, as accelerometers and/or gyroscopes. Fabrication of these trenches may involve lateral oxidation, whereby columns of semiconductor material are oxidized.

Abstract: There is disclosed in one example an audio processor, including: an audio crossover to separate a first frequency band from a second frequency band, the first frequency band having a lower frequency band than the second frequency band; an excursion estimator to estimate from information of the first frequency band a predicted excursion of a low-frequency driver; an interpolator to interpolate an adjustment to the second frequency band to compensate for the estimated excursion; and circuitry to drive the adjusted second frequency to a receiver.

Abstract: Herein disclosed are approaches for protecting sensitive information within a fingerprint authentication system that can be snooped and utilized to access the device, secured information, or a secured application. The approaches can utilize encryption keys and hash functions that are unique to the device in which the fingerprint authentication is being performed to protect the sensitive information that can be snooped.

Abstract: Relaxation oscillators with delay compensation are provided herein. In certain embodiments, a relaxation oscillator includes a capacitor, a current source that outputs a charging current, and control circuitry that operates to selectively charge the capacitor with the charging current. The control circuitry includes a primary or main comparator operable to compare a charging voltage of the capacitor to a threshold voltage. The relaxation oscillator further includes delay compensation circuitry coupled to the capacitor and operable to adjust the threshold voltage to provide compensation for a delay of the control circuitry.

Abstract: Disclosed herein are systems and techniques for general purpose input/output (GPIO)-to-GPIO communication in a multi-node, daisy-chained network. In some embodiments, a transceiver may support GPIO between multiple nodes, without host intervention after initial programming. In some such embodiments, the host may be required only for initial setup of the virtual ports. In some embodiments, GPIO pins can be inputs (which may change virtual ports) or outputs (which may reflect virtual ports). In some embodiments, multiple virtual ports may be mapped to one GPIO output pin (with the values OR'ed together, for example). In some embodiments, multiple GPIO input pins may be mapped to one virtual port. For example, multiple GPIO input pin values may be OR'ed together, even if they come from multiple nodes.

Abstract: An electronic circuit comprises an input voltage circuit, an analog-to-digital converter (ADC) circuit, and logic circuitry. The input voltage circuit is configured to generate multiple input voltages. The ADC circuit is configured to convert the multiple input voltages to first digital values using the first longer ADC acquisition time and convert the multiple input voltages to second digital values using the second shorter ADC acquisition time. The logic circuitry is configured to determine calibration information for the ADC circuit using the first digital values and the second digital values, and scale analog-to-digital (A/D) conversion results of the ADC circuit using the calibration information.

Abstract: Improved track and hold (T/H) circuits can help analog-to-digital converters (ADCs) achieve higher performance and lower power consumption. The improved T/H circuits can drive high speed and interleaved ADCs, and the design of the circuits enable additive and multiplicative pseudo-random dither signals to be injected in the T/H circuits. The dither signals can be used to calibrate (e.g., linearize) the T/H circuits and the ADC(s). In addition, the dither signal can be used to dither any remaining non-linearity, and to calibrate offset/gain mismatches in interleaved ADCs. The T/H circuit design also can integrate an amplifier in the T/H circuit, which can be used to improve the signal-to-noise ratio (SNR) of the ADC or to act as a variable gain amplifier (VGA) in front of the ADC.

Abstract: Various examples are directed to configuring a configurable hardware module to perform a measurement of a physical quantity. A configuration manager may receive an indication of the physical quantity and performance factor data describing the measurement of the physical quantity. The configuration manager may generate a hardware configuration of the hardware based at least in part on the indication of the physical quantity and the performance factor data. The hardware configuration may comprise instruction data to configure the hardware module to execute a dynamic measurement of the physical quantity. The configuration manager may also generate configuration data describing the hardware configuration, wherein the configuration data comprises simulation data comprising input parameters for a simulation of the hardware configuration and hardware configuration data for configuring a hardware module to implement at least a portion of the hardware configuration.

Abstract: A voltage converter circuit comprises a charge pump circuit, a switching converter circuit, and a control circuit. The charge pump circuit includes multiple switch circuits connected in series. The switching converter circuit includes a first inductor coupled to an output node of the voltage converter circuit, and a second inductor coupled to a series connection of the multiple switch circuits. The control circuit is configured to control activation of the multiple switch circuits to generate a regulated voltage at the output node, and to activate each of the multiple switch circuits when a drain to source voltage of the switch circuit is zero volts.

Abstract: Bias networks for amplifiers are disclosed. An example bias network includes an adaptive bias circuit, configured to generate a bias signal for an amplifier, and further includes a coupling circuit, configured to couple the adaptive bias circuit to the amplifier. The coupling circuit is made adaptive in that its' impedance depends on a power level of an input signal to be amplified by the amplifier. By configuring the coupling circuit to have a variable impedance that depends on the power level of the input signal, the coupling circuit may adapt to the input power level and, thereby, may modify the bias signal to reduce/optimize at least some of the nonlinearity that may be introduced to the bias signal by the adaptive bias circuit.

Abstract: Systems and methods described herein relate to fingerprint-on-display recognition. In particular, the systems and methods described herein may recognize a fingerprint when a finger of a user is placed on a display and authenticate the user based on the recognized fingerprint. Further, the embodiments described herein may utilize multiple colors and/or secondary factors to reduce erroneous authentications of the user. The approaches may improve the accuracy of fingerprint authentication by using the multiple colors and/or secondary factors.

Abstract: A high-voltage level shifter circuit that is capable of level shifting a signal from a low-voltage rail to a high-voltage rail for effective gate driving of a top power switch, with a short propagation delay and a high common-mode transient immunity (CMTI). The high CMTI high-voltage level shifter circuit can include a differential input and isolation stage, a high dv/dt sensor and cancellation stage, at least one differential and common-mode gain stage, and an output buffer stage.

Abstract: Techniques to reduce the on-time of a multi-stage ADC circuit by combining the settling time of a signal conditioning circuit, e.g., buffer circuit, and the setting time of a residue amplifier when cancelling the offset of the signal conditioning circuit. The techniques can allow the signal conditioning circuit and the residue amplifier to settle together.

Abstract: System and apparatus for portable gas detection. Specifically, this disclosure describes apparatuses and systems for optical gas detection in a compact package. There is a need for a very compact, low-power, gas detection system for gases such as CO2, NOx, water vapor, methane etc. This disclosure provides an ultra-compact and highly efficient optical measurement system based on principals of optical absorption spectroscopy. It reduces the size of the instrument as well its power consumption by more than an order of magnitude making it possible to deploy it widely. There is an identified need for large number of distributed gas sensors to improve human health, environment, and save energy usage.

Abstract: A PoE system includes a PSE connected via a shielded twisted wire pair to a PD, where differential data is transmitted over only the wire pair, and where DC power is transmitted via the wires in the wire pair conducting a DC voltage in parallel while using the shield conductor as ground. A low power handshaking routine is performed by a PSE controller and a PD controller by conducting a source current through the wires in parallel and a return current through the shield conductor. Center tap auto-transformers are used to connect the two wires to the PSE and PD controllers and to a DC voltage source in the PSE. After a successful handshaking routine, the PSE couples the DC voltage source between the wire pair and the shield conductor by closing a first power switch. The PD controller then closes a second power switch to power a load.

Abstract: Techniques that can prevent the low dropout (LDO) output voltage degradation that occurs with conventional LDO regulators, even with large LDO supply variations. An LDO regulator circuit can include another loop that is much slower than the main LDO regulator loop, concentrates the load regulation, and fixes the voltage regulation runaway problem due to the large supply variation with large frequency content. The LDO regulator circuit can include a negative feedback correction loop that corrects the LDO output by, in some examples, adding sink current to the main voltage regulation loop via a programmable current sink element.

Abstract: Device for improving an optical detecting smoke apparatus and implementing thereof. Apparatus and methods for detecting the presence of smoke in a small, long-lasting smoke detector are disclosed. Specifically, the present disclosure shows how to build one or more optimized blocking members in a smoke detector to augment signal to noise ratio. This is performed while keeping the reflections from the housing structure to a very low value while satisfying all the other peripheral needs of fast response to smoke and preventing ambient light. This allows very small measurements of light scattering of the smoke particles to be reliable in a device resistant to the negative effects of dust. In particular, geometrical optical elements, e.g., cap and optical defection elements, are disclosed.

Abstract: The present disclosure provides an improved Rogowski-type current sensor. The current measurement coil, and the compensation coil are provided on the same board. The measurement coil and the compensation coil are arranged such that they at least partially overlap by virtue of each repeatedly changing side of the board. This arrangement makes the current sensor far better at rejecting interference than certain other PCB Rogowski type coil arrangements.

Abstract: Techniques are described that can be used to extract an offset and a gain of a signal chain, which can be used for digital correction of an analog-to-digital converter (ADC) output to help achieve a life time and temperature stable ADC output. For example, using various techniques, a value for a voltage reference VREF and a value for ground (GND) (or other reference voltage) can be converted, which can then be used to determine gain and offset, respectively, of the signal chain.

Abstract: Techniques for improving noise performance while processing signals received from an electrochemical sensor are provided. In an example, an interface circuit can include a first amplifier configured to provide a voltage to a counter electrode of an electrochemical sensor, a second amplifier configured to receive sensor information from a working electrode of the electrochemical sensor and to provide concentration information using the sensor information. In certain examples, an input of the first amplifier can be directly coupled to an input of the second amplifier to attenuate noise, of either the first amplifier or the second amplifier, within the concentration information provided by the second amplifier.