Abstract: Micromachined inertial devices are presented having multiple linearly-moving masses coupled together by couplers that move in a linear fashion when the coupled masses exhibit anti-phase motion. The couplers move in opposite directions of each other, such that one coupler on one side of the movable masses moves in a first linear direction and another coupler on the opposite side of the movable masses moves in a second linear direction opposite the first linear direction. The couplers ensure proper anti-phase motion of the masses.

Abstract: Micromachined inertial devices are presented having multiple linearly-moving masses coupled together by couplers that move in a linear fashion when the coupled masses exhibit linear anti-phase motion. Some of the described couplers are flexural and provide two degrees of freedom of motion of the coupled masses. Some such couplers are positioned between the coupled masses. Using multiple couplers which are arranged to move in linearly opposite directions during linear anti-phase motion of the coupled masses provides momentum-balanced operation.

Abstract: Micromachined inertial devices are presented having multiple linearly-moving masses coupled together by couplers that move in a linear fashion when the coupled masses exhibit anti-phase motion. The couplers move in opposite directions of each other, such that one coupler on one side of the movable masses moves in a first linear direction and another coupler on the opposite side of the movable masses moves in a second linear direction opposite the first linear direction. The couplers ensure proper anti-phase motion of the masses.

Abstract: A microfluidic ion detector for detecting heavy metal ions in liquid and particulate matter from gas samples is described. The microfluidic ion detector includes a sample extraction structure for extracting sample ions from a sample liquid or extracting sample ions from the particulate matter of a gas sample, a separation structure for separating sample ions of different types once extracted, and a detection structure for detecting the sample ions. The microfluidic ion detector also includes a reference reservoir providing a reference ion against which the sample may be calibrated based on the operation of the separation structure. A portable, self-calibrating ion detector may be realized by including the described components on a single substrate.

Abstract: A power converter circuit can be operated in a constant-current mode when a monitored output current exceeds a specified over-current threshold. A value representing an output voltage of the power converter circuit can be compared to a soft-start voltage reference value. The soft-start voltage reference value can be set (or reset) to a value representing the output voltage of the power converter when the difference between the soft-start voltage reference value and the value representing the output voltage of the power converter is greater than a specified threshold. The output voltage of the power converter can be regulated using the soft-start voltage reference value as a target voltage including ramping the soft-start voltage reference value at specified rate to maintain the soft-start voltage reference value within a specified range of a specified regulated output voltage value, such as to constrain a slew rate of the regulated output voltage.

Abstract: A voltage regulator is provided comprising: a pass transistor that includes a first node coupled to receive an input voltage and a second node coupled to provide a regulated voltage and a control node; an amplifier circuit coupled to produce a control voltage on a control line that is coupled to control a voltage at the control node of the pass transistor, based at least in part upon a reference voltage and the regulated voltage; a switch configured to transition between a first switch state in which the switch couples the control line to a turn-off voltage having a value to turn off the pass transistor and a second switch state in which the switch decouples the control line from the turn-off voltage; and a switch control circuit configured to maintain the switch in the first switch state during a first time interval while the input voltage ramps up and to transition the switch to the second switch state after the first time interval.

Abstract: A device authentication system for use with an authenticatable device having a physically-unclonable function and constructed to, in response to input, of challenge C, internally generate an output O characteristic to the PUF and the challenge C, and configured to: i) upon receiving challenge C, generate a corresponding commitment value that depends upon a private value r, and ii) upon receiving an authentication query that includes the challenge C and a nonce, return a zero knowledge proof authentication value that corresponds to the commitment value.

Abstract: An isolator system has an isolator that generates differential isolator signals and a receiver that generates digital data representative of signals received from the isolator. The system also may include an RC filter coupled between the isolator and the receiver. During operation, the filter may distribute transient signals across various circuit paths in the isolator, only some of which are coupled to the receiver inputs. Over time, the filter may attenuate transient contributions at the receiver inputs. In this manner, the filter may limit effects of these common mode transients.

Abstract: A method for testing a DAC comprising controlling the DAC digitally to cause it to produce a known desired analog output, for example a fixed amplitude sine wave; determining the duration of fixed voltage segments of the actual output of the DAC and using the duration of the fixed voltage segments to assess or determine performance of the DAC.

Abstract: A resilient device authentication system for use with one or more managed devices each including a physical unclonable function (PUF), comprises: one or more verification authorities (VA) each including a processor and a memory loaded with a complete verification set (CVS) that includes hardware part-specific data associated with the managed devices' PUFs and metadata, the processor configured to create a limited verification set (LVS) through one-way algorithmic transformation of hardware part-specific data together with metadata from the loaded CVS so as to create a LVS representing both metadata and hardware part-specific data adequate to redundantly verify all of the hardware parts associated with the LVS; and one or more provisioning entities (PE) each connectable to a VA and including a processor and a memory loaded with a LVS, and configured to select a subset of the LVS so as to create an application limited verification set (ALVS).

Abstract: A control circuit eliminates the Zeno phenomenon in a power supply controller while transferring control from a primary side controller to a secondary side controller. The primary side controller generates a feedback voltage (e.g., threshold voltage) that is input to a comparator. An output node voltage of the control circuit is fed back to the linear amplifier to be compared with the threshold voltage. While the output node voltage is less than the threshold voltage, a charge pump is coupled to the output node of the control circuit. After the output node voltage has toggled around the threshold voltage a number of times, the comparator output node is coupled to the output node of the control circuit and the charge pump is decoupled from the output node. When the output node voltage has discharged to be equal to the threshold voltage, control is handed off from the primary side controller to the secondary side controller.

Abstract: In a cascaded integrator comb (CIC) filter, a time-varying gain is added before the last integrating stage transforming its sub optimal boxcar impulse response into an FIR filter of arbitrary length. Make the coefficients sparse and taking them from a set of small integers leads to an efficient hardware implementation that does not compromise any of the essential CIC filter characteristics especially the overflow handling. The proposed sparse CIC structure can improve the worst case stop band attenuation by as much as 10 dB while occupying 77% of the chip area and consuming 30% less power compared to a standard a 5th order CIC filter, and reducing the overall bit growth of the filter and the amount of high rate operations. Design examples are given illustrating the advantages and flexibility of the proposed structure.

Abstract: Systems and methods for synchronous demodulation using passive sampled analog filtering are disclosed. A system for synchronous demodulation includes an input channel for accepting an input signal, a first passive sampled analog filter for filtering the input signal, a mixer for mixing the filtered input signal and outputting a mixed signal, a second passive sampled analog filter for filtering the mixed signal, and an output channel for outputting the filtered mixed signal.

Abstract: An optical coupler can be provided for coupling a light beam into a waveguide. The optical coupler can include a stepped structure, such as to reduce difficulties during manufacture, reduce expenses associated with manufacture, and additionally, to provide an increased acceptance angle of the optical coupler. The waveguide can include a guiding region where a cladding thickness can be increased relative to a coupling region, such as to reduce losses due to evanescent outcoupling in the guiding region.

Abstract: Present disclosure describes an improved scaling mechanism for a multi-stage fixed-point FFT algorithm used to process signals received by radar or sonar systems. Proposed scaling includes scaling an output of every pair of consecutive butterfly stages of the FFT algorithm by a scaling factor equal to two times of the inverse of a growth factor for the pair of consecutive butterfly stages for the FFT algorithm for a purely complex exponential input signal. Besides this scaling, input signals are allowed to overflow by saturation. Such mechanism yields adequate performance of radar and sonar receivers implementing fixed-point FFTs for any types of input signals, from random to substantially complex exponential or sinusoidal signals. Proposed scaling achieves a balance between having signal to noise ratio (SNR) that is possible to obtain for a particular input signal and SNR that is needed to successfully process that signal for radar and sonar applications.

Abstract: Apparatus and methods for phase synchronization of phase-locked loops (PLLs) are provided. In certain configurations, an RF communication system includes a PLL that generates one or more output clock signals and a phase synchronization circuit that synchronizes a phase of the PLL. The phase synchronization circuit includes a sampling circuit that generates samples by sampling the one or more output clock signals based on timing of a reference clock signal. Additionally, the phase synchronization circuit includes a phase difference calculation circuit that generates a phase difference signal based on the samples and a tracking digital phase signal representing the phase of the PLL. The phase synchronization circuit further includes a phase adjustment control circuit that provides a phase adjustment to the PLL based on the phase difference signal so as to synchronize the PLL.

Abstract: Isolators for providing electrical isolation between two circuits operating at different voltages are described, in which multiple semiconductor dies including the isolator components and the components of the two circuits are stacked on top of each other to provide a laterally-compact arrangement. An isolation barrier electrically separates the two circuits, and the isolator may provide a communication channel for transfer of information and/or power between the two circuits. The isolator may be included in an integrated device having a stacked die configuration where a first semiconductor die includes the isolator and components of the first of the two circuits, and a second semiconductor die positioned over the first semiconductor die includes components of the second of the two circuits. Two components of the isolator may be formed in separate layers of the first semiconductor die.

Abstract: Mechanical resonators including doped piezoelectric active layers are described. The piezoelectric active layer(s) of the mechanical resonator may be doped with a dopant type and concentration suitable to increase the electromechanical coupling coefficient of the active layer. The increase in electromechanical coupling coefficient may all for improved performance and smaller size mechanical resonators than feasible without using the doping.

Abstract: Capped microelectromechanical systems (MEMS) devices are described. In at least some situations, the MEMS device includes one or more masses which move. The cap may include a stopper which damps motion of the one or more movable masses. In at least some situations, the stopper damps motion of one of the masses but not another mass.

Abstract: Various examples are directed to crosspoint switches and methods of use thereof. An example cross point switch comprises a first row buffer, a second row buffer, a first column buffer, and a second column buffer. The crosspoint switch may also comprise a first switch that, when closed, electrically couples the second row buffer to the first column buffer, and a correction controller. The correction controller may be configured to send a first correction signal to the first row buffer; send a second correction signal to the second row buffer; receive an indication that the first switch is closed; send a third correction signal to the first column buffer; and send a fourth correction signal to the second column buffer.