Abstract: Apparatus and methods for rotary traveling wave oscillators (RTWOs) are disclosed. In certain embodiments, an RTWO system include an RTWO ring that carries a traveling wave, a plurality of selectable capacitors distributed around the RTWO ring and each operable in a selected state and an unselected state, and a decoder system that controls selection of the plurality of selectable capacitors based on a frequency tuning code. The frequency tuning code includes a fine tuning code and a coarse tuning code, and the decoder system is operable to maintain a constant number of capacitors that toggle state for each value of the fine tuning code.

Abstract: Apparatus and methods for controlling voltage converter are provided. In an example, a switched-mode DC-DC voltage converter can include an inductor, at least four switches coupled to the inductor and configured to direct current through the inductor to provide a desired output voltage at an output voltage terminal of the voltage converter using an input voltage supply and a ground reference of the converter, and a controller circuit, configured to receive an indication of inductor current through the inductor and to use the slope of the inductor current to control a change between two operating modes of a group of operating modes that include a boost operating mode, a buck operating mode, and a buck-boost operating mode.

Abstract: An example current mirror arrangement includes a current mirror circuit, configured to receive an input current signal at an input transistor Q1 and output a mirrored signal at an output transistor Q2. The arrangement further includes a semi-cascoding circuit that includes transistors Q3, Q4, and a two-terminal passive network. The transistor Q3 is coupled to, and forms a cascode with, the output transistor Q2. The transistor Q4 is coupled to the transistor Q3. The base/gate of the transistor Q3 is coupled to a bias voltage Vref, and the base/gate of the transistor Q4 is coupled to a bias voltage Vref1 via the two-terminal passive network. Nonlinearity of the output current from such a current mirror arrangement may be reduced by selecting appropriate impedance of the two-terminal passive network and selecting appropriate bias voltages Vref and Vref1.

Abstract: According to some aspects, there is provided a microelectromechanical systems (MEMS) device wherein one or more components of the MEMS device exhibit attenuated motion relative to one or more other moving components. The MEMS device may comprise a substrate; a proof mass coupled to the substrate and configured to move along a resonator axis; and a first shuttle coupled to the proof mass and comprising one of a drive structure configured to drive the proof mass along the resonator axis or a sense structure configured to move along a second axis substantially perpendicular to the resonator axis in response to motion of the proof mass along the resonator axis, wherein displacement of at least a first portion of the proof mass is attenuated relative to displacement of the first shuttle and/or a second portion of the proof mass.

Abstract: Columnar multi-axis microelectromechanical systems (MEMS) devices (such as gyroscopes) balanced against undesired linear and angular vibration are described herein. In some embodiments, the columnar MEMS device may comprise at least two multiple-mass columns, each having at least three proof masses and being configured to sense rotation about a respective axis. The motion and mass of the proof masses may be controlled to achieve linear and rotational balancing of the MEMS device. The columnar MEMS device may further comprise one or more modular drive structures disposed alongside each multiple-mass column to facilitate displacement of the proof masses of a respective column. The MEMS devices described herein may be used to sense roll, yaw, and pitch angular rates.

Abstract: Described herein are techniques for a system to track usage of a software application on a remote device, without having connectivity to the remote device. The system transmits an activation token to a computing device different from the remote device to activate the software application, and receives a deactivation token generated by the remote device from the computing device when the software application is deactivated. The system uses transmission of an activation token and receipt of a deactivation token as indicators of start and end times of use of the software application. For example, the system uses the indicated start and end times to determine a billing period for use of the software application.

Abstract: A Multi-I/O SPI for precision converters supports a Dual/Quad/Octal SPI to support the speed requirements for digital transmission and also includes a special mode that can be enabled by hardware and/or software to remove the bit scrambling requirement dictated by the JEDEC standard. The special mode removes the scramble requirement and associates each of the bidirectional data lines to a specific channel. The special mode provides backward compatibility that permits the precision converter to be used with controllers that do not natively support the JEDEC standard. Also, the Multi-I/O SPI includes registers divided into a primary region that is accessed only in default mode at power-up for write and/or read operations, and a secondary region that is accessed by any mode enabled in the control register. By restricting access to the “control” register area to a pre-defined mode in the converter at power-up, the access mode can be controlled.

Abstract: Z-axis teeter-totter accelerometers with embedded movable structures are disclosed. The teeter-totter accelerometer may include an embedded mass which pivots or translates out-of-plane from the teeter-totter beam. The pivoting or translating embedded mass may be positioned to increase the sensitivity of the z-axis accelerometer by providing greater z-axis displacement than the teeter-totter beam itself exhibits.

Abstract: A cascaded configuration of regulator circuits can be co-integrated within a commonly-shared integrated circuit package (such as an integrated electronic module). Such co-integration can include placing a switched-mode regulator circuit in close proximity to a linear regulator circuit. Magnetic field coupling between the regulator circuits is generally a non-linear function of a separation between the circuits. The switched-mode regulator circuit can generate noise that may adversely impact the linear regulator output. Magnetic coupling between the regulator circuits within the module package can be suppressed or eliminated using a magnetic barrier. The barrier can be magnetically permeable and electrically non-conductive.

Abstract: Time of Flight (ToF) image processing systems and methods for proximity detection are disclosed. In particular, use of a separate proximity detector can be eliminated by using the time of flight image processing system as disclosed herein. In particular, the time of flight image processing system has two modes: a low resolution proximity detection mode and a high resolution imaging mode.

Abstract: Herein disclosed are multiple embodiments of a signal-processing circuit that may be utilized in various circuits, including conversion circuitry. The signal-processing circuit may receive an input and produce charges on multiple different capacitors during different phases of operation based on the input. The charges stored on two or more of the multiple different capacitors may be utilized for producing an output of the signal-processing circuit, such as by combing the charges stored on two or more of the multiple different capacitors. Utilizing the charges on the multiple different capacitors may provide for a high level of accuracy and robustness to variations of environmental factors, and/or a low noise level and power consumption when producing the output.

Abstract: Aspects of the present disclosure provide miniaturized isolator modules capable of transferring power and/or data signals across an isolation barrier by way of a transformer while maintaining intrinsic safety (IS) compliance. For example, the isolator modules may provide power from a non-IS side to an IS side of the isolation barrier while protecting the IS side in the event of an overvoltage and/or overcurrent event on the non-IS side. In some aspects, an isolator module includes one or more silicon protection devices, which facilitate the miniaturization of the isolator module while maintaining protection against overvoltage and/or overcurrent events in accordance with IS standards. In some aspects, an isolator module includes a transformer adapted for IS compliance. For example, coils of the transformer may be disposed on opposing sides of an isolation barrier having a thickness of at least 200 microns.

Abstract: Amplifiers with wide input range and low input capacitance are provided. In certain embodiments, an amplifier input stage includes a pair of input terminals, a pair of n-type input transistors, a first pair of isolation switches connected between the input terminals and the n-type input transistors, a pair of p-type input transistors, and a second pair of isolation switches connected between the input terminals and the p-type input transistors. The amplifier input stage further includes a control circuit that determines whether to use the n-type input transistors and/or the p-type input transistors for amplification based on a detected common-mode voltage of the input terminals. The control circuit opens the first pair of isolation switches to decouple the input terminals from the n-type input transistors when unused, and opens the second pair of isolation switches to decouple the input terminals from the p-type input transistors when unused.

Abstract: Aspects of this disclosure relate to a magnetic sensor system for measuring any desired combination of measuring torque, rotation angle, and turn count of a shaft. The shaft may include two portions connected by a torsion element. The system can measure rotation angle using a magnetic target coupled to the shaft that produces a magnetic field that varies as a function of rotation angle. The system can measure torque applied to the shaft by measuring the difference in rotation angles between the two portions of the shaft and factoring in a torsion coefficient. The system can track a turn count of the shaft using a multi-turn sensor. The magnetic sensor system may be part of an electric power assisted steering (EPAS) system.

Abstract: A wide bandwidth ADC circuit that combines a resistive-input continuous-time sigma-delta ADC circuit with a second ADC circuit having a switched capacitor input. The combination of these two ADC circuits can achieve an easy-to-drive, alias free, wide bandwidth ADC that has excellent DC precision.

Abstract: Systems and method for improving stability and performance in class-D modulators. In particular, a multi-cycle feedback network is positioned around a quantizer of a digital class-D amplifier. The multi-cycle feedback network allows the main class-D feedback loop to have multiple clock cycles of delay.

Abstract: Systems and methods for improving the efficiency of a rotational dynamic element matching (DEM) for Delta Sigma converters. In some implementations, the systems and methods are provided a for reducing intersymbol interference (ISI) of a Delta Sigma converter. A delta sigma converter architecture can include multiple I-DACs, and the output from each I-DAC can vary from the other I-DACs. Techniques are disclosed for decreasing mismatch among multiple I-DACs while improving efficiency of rotational dynamic element matching.

Abstract: Systems and methods for a power-efficient 3-level digital-to-analog converter. A converter cell using a current starving technique keeps a portion of the converter cell turned on in a low power mode, as opposed to completely turning off current in selected modes. A conversion system keeps a first set of converters active while allowing a second set of converters to be powered down. Systems and methods presented save power and allow for efficient reactivation of converters.

Abstract: A passive wireless sensor may be wirelessly coupled with an interrogator. The sensor uses multiple antennas to receive an interrogation signal from the interrogator and compares a path length difference between the signal received at each antenna. The path length difference changes based on the relative position of the sensor and interrogator. Using the path length difference, the sensor transmits a response signal to the interrogator. The interrogator analyzes the response signal to determine sensor position. The interrogator compares the determined sensor position to a previous known sensor position to determine if an attack has occurred, such as a replay, counterfeit, or tampering attack. The sensor may include cryptographic circuitry that scrambles the response signal, thwarting an attack such as a sniffing attack. The interrogator may include multiple antennas and determine a position of the sensor by calculating an angle-of-arrival that enhances a signal from the sensor, via beamforming.

Abstract: Mechanisms for reducing or eliminating a quantization error caused by a quantizer of a continuous-time (CT) residue generation system are disclosed. In particular, systems and methods described herein are based on using a dither generation and injection circuit that can perform a high-pass filtering of the additive dither signal (i.e., a high-pass shaped dither signal). Using high-pass shaped dither signals is expected to improve quantizer linearity without significantly reducing the available error correction range. The applied dither may be particularly effective at minimizing signal-dependent distortion in ADC output spectrum caused by the quantizer when the quantization error cancellation accuracy may be insufficient.