Abstract: A sampled analog circuit is divided into at least two segments, each segment receiving sampled analog data and a respective subset of bits of a filter coefficient. The at least two segments can have digital-to-capacitance circuits with substantially identical ranges of capacitance values. One or more outputs from the segments can be scaled to reflect a position of the subset of bits in the bits of the filter coefficient, and thereafter added in the analog domain to produce a filtered output signal that may then be digitized. Alternatively, the outputs from the segments may be digitized before being scaled and/or added in the digital domain.

Abstract: Apparatus and methods for providing an ultra-low power voltage converter are provided. In an example, a method can include receiving an ultra-low power command at a voltage regulator circuit from a load, disabling charge transfer of a regulator of the regulator circuit during an ultra-low power mode of operation in response to a first state of the ultra-low power command, detecting a change in the low power command or in a timeout signal, receiving an indication that the output voltage of the regulator is below a low voltage threshold in response to the change, discharging the output voltage of the regulator for a reset interval in response to the indication, and enabling charge transfer of the regulator after discharging the output voltage.

Abstract: A passive wireless sensor system is disclosed that includes components fabricated from carbon nanotube (CNT) structures. In some situations, the passive wireless sensor system includes a CNT structure sensor and an antenna that communicates wirelessly by altering an impedance of the antenna. The passive wireless sensor system includes a non-battery-powered energy storage device that harvests energy from carrier signals received at the antenna. The antenna and the energy storage device can be formed from CNT structures.

Abstract: Apparatus and methods for fractional-N synthesizer phase-locked loops with multi-phase oscillators are provided. In certain configurations, a fractional-N PLL includes a time-to-digital converter (TDC), a digital loop filter, a multi-phase oscillator, and fractional division circuitry. The multi-phase oscillator includes multiple taps used to generate multiple clock signal phases that are provided to the fractional division circuitry to reduce the fractional-N PLL's quantization error. The fractional division circuitry includes a tap error correction circuit for compensating for errors in tap positions of the multi-phase oscillator. By including the tap error correction circuit, the phase noise and/or jitter performance of the fractional-N PLL can be enhanced.

Abstract: Apparatus and methods for electrostatic discharge (ESD) protection of radio frequency circuits are provided. In certain configurations, an integrated circuit includes a first pin, a second pin, a forward ESD protection circuit, and a reverse ESD protection circuit. The forward ESD protection circuit includes one or more P+/N-EPI diodes, one or more ESD protection devices, and one or more P-EPI/N+ diodes electrically connected in series between the first pin and the second pin. A first P+/N-EPI diode of the one or more P+/N-EPI diodes includes an anode electrically connected to the first pin. The reverse ESD protection circuit comprising one or more P+/N-EPI diodes, one or more ESD protection devices, and one or more P-EPI/N+ diodes electrically connected in series between the second pin and the first pin. A first P-EPI/N+ diode of the one or more P-EPI/N+ diodes includes a cathode electrically connected to the first pin.

Abstract: A substantially planar waveguide for dynamically controlling the out-of-plane angle at which a light beam exits the waveguide. Generally, liquid crystal materials may be disposed within a waveguide in a cladding proximate or adjacent to a core layer of the waveguide. In one example, the waveguide may contain one or more taper regions such that the light beam exits the waveguide and propagates out-of-the-plane of the waveguide into an out-coupling medium at a propagation angle. In one example, the waveguide may contain one or more electrodes onto which one or more voltages may be applied. The magnitude of the propagation angle may be electronically controlled by stored by controlling or altering the magnitude of the one or more applied voltages.

Abstract: Embodiments of the present disclosure provide code readers for reading codes provided as patterns imprinted on objects. Light interacts with a pattern by e.g. being reflected from or transmitted through the pattern, and at least some of the light that has interacted with the pattern is incident on photosensitive element(s) of one or more photodetectors of a code reader. The code reader employs centroid-measuring photodetector(s), i.e. photodetectors that detect light in such a manner that centroid of a pattern can be obtained directly from the photocurrents generated as a result of the photosensitive elements detecting light incident thereon. The code reader is then configured to process the detected light to determine a centroid of the pattern from the detected light and to decode data encoded in the pattern based on a position of the centroid. Such code readers are substantially less complex than camera-based devices and avoid mechanical scanning.

Abstract: Various embodiments of switched amplifiers are disclosed herein. In some embodiments, a switched amplifier may include a first amplifier; a second amplifier; an input matching network common to both the first and second amplifiers; and at least one switch to couple an input of the switched amplifier, via the input matching network, to one of the first amplifier or the second amplifier. In some embodiments, a switched amplifier may include a first amplifier; a second amplifier; an input matching network common to both the first and second amplifiers or an output matching network common to both the first and second amplifiers; and a bias generation circuit to selectively (1) provide a first bias current to the first amplifier or (2) provide a second bias current to the second amplifier, wherein the second bias current is less than the first bias current.

Abstract: A substantially planar waveguide for dynamically controlling the out-of-plane angle at which a light beam exits the waveguide. Generally, liquid crystal materials may be disposed within a waveguide in a cladding proximate or adjacent to a core layer of the waveguide. In one example, the waveguide may contain one or more taper regions such that the light beam exits the waveguide and propagates out-of-the-plane of the waveguide into an out-coupling medium at a propagation angle. In one example, the waveguide may contain one or more electrodes onto which one or more voltages may be applied. The magnitude of the propagation angle may be electronically controlled by altered by controlling or altering the magnitude of the one or more applied voltages.

Abstract: Apparatus and techniques for controlling measurement of an electrical parameter of an energy source can be used to obtain information for use in enhancing a power transfer efficiency between the energy source and a load. For example, during a first measurement cycle, information indicative of the electrical parameter of the energy source can be obtained using a measurement circuit during a first sampling duration in which the load is decoupled from the energy source. The information indicative of the obtained electrical parameter can be compared to a threshold. In response to the comparing, a different second sampling duration can be determined for use in obtaining information indicative of the electrical parameter during a subsequent measurement cycle. The information indicative of the electrical parameter of the energy source includes information for use in enhancing the power transfer efficiency between the energy source and the load.

Abstract: Angular accelerometers are described, as are systems employing such accelerometers. The angular accelerometers may include a proof mass and rotational acceleration detection beams directed toward the center of the proof mass. The angular accelerometers may include sensing capabilities for angular acceleration about three orthogonal axes. The sensing regions for angular acceleration about one of the three axes may be positioned radially closer to the center of the proof mass than the sensing regions for angular acceleration about the other two axes. The proof mass may be connected to the substrate though one or more anchors.

Abstract: Disclosed herein are envelope detectors with high input impedance, and related methods and systems. In some embodiments, an envelope detector with high input impedance may include: a swinging stage including first, second, and third transistors, wherein the third transistor and an active transistor are arranged as a differential pair, the first transistor is the active transistor when an input to the envelope detector is positive, and the second transistor is the active transistor when the input to the envelope detector is negative; and a feedback circuit, coupled to the swinging stage, to provide an output signal representative of a rectification of the input.

Abstract: A method of manufacture of a sensor, the method comprising, in a first fabrication facility, forming one or more components of the sensor on a substrate; and in a second fabrication facility depositing a sensor layer, such as a magnetoresistive sensor, onto the substrate or over the one or more components. Otherwise contaminating effects of depositing magnetoresistive materials can thus be confined to the second fabrication facility, permitting more advanced fabrication equipment and techniques to be employed in the first fabrication facility.

Abstract: Apparatus and methods are disclosed related to managing characteristics of a mobile device based upon capacitive detection of materials proximate the mobile device, a capacitive gesture system that can allow the same gestures be used in arbitrary locations within range of a mobile device. One such method includes receiving a first capacitive sensor measurement with a first capacitive sensor of the mobile device. The method further includes determining a value indicative of a material adjacent to the mobile device based on a correspondence between the first capacitive sensor measurement and stored values corresponding to different materials. The method further includes sending instructions to adjust a characteristic of the mobile device based on the determined value indicative of the material adjacent to the mobile device. In certain examples, gesture sensing can be performed using capacitive measurements from the capacitive sensors.

Abstract: Systems and methods disclosed herein provide for enhancing the low frequency (DC) gain of an operational amplifier with multiple correlated level shifting capacitors. In an embodiment, the operational amplifier is level shifted with a first correlated level shifting capacitor in a first phase and, then, is level shifted again with at least a second correlated level shifting capacitor in at least a second, non-overlapping, consecutive phase. In an embodiment, the multiple correlated level capacitors are controlled by a switching circuit network.

Abstract: A temperature sensing system can include first and second temperature sensing circuits and a digitizing encoder. The first and second temperature sensing circuits can include respective devices with semiconductor junction areas. Temperature information can be determined from one or more characteristic signals measured from the temperature sensing circuits. A feedback circuit can be configured to provide one or more offset signals to the digitizing encoder. The one or more offset signals can correspond to components or characteristics of the first and second temperature sensing circuits. In an example, at least one of the first and second temperature sensing circuits can include an adjustable load circuit for use with the other of the first and second temperature sensing circuits.

Abstract: A comparator circuit's signal range can be enhanced using an input signal attenuation circuit. In an example, a comparator circuit receives an input signal and a reference signal. The input signal can be conditioned by one or both of the attenuation circuit and a conditioning circuit, and a resulting conditioned signal can be presented to a compare element. Under first operating conditions where the input signal is approximately equal to the reference signal, the attenuation circuit can be substantially bypassed and a first resulting conditioned signal can be presented to the compare element. Under second operating conditions where the input signal is substantially greater than the reference signal, the attenuation circuit receives a portion of the input signal and a different second resulting conditioned signal can be presented to the compare element.

Abstract: Embodiments of the present disclosure provide mechanisms that enable designing an FIR filter that would have a guaranteed globally optimal magnitude response in terms of the minimax optimality criterion given a desired weight on the error in the stopband versus the passband. Design of such a filter is based on a theorem (“characterization theorem”) that provides an approach for characterizing the global minimax optimality of a given FIR filter h[n], n=0, 1, . . . , N, where optimality is evaluated with respect to a magnitude response of this filter, |H(ej?)|, as compared to the desired filter response, D(?), which is unity in the passband and zero in the stopband. The characterization theorem enables characterizing optimality for both real-valued and complex-valued filter coefficients, and does not require any symmetry in the coefficients, thus being applicable to all non-linear phase FIR filters.

Abstract: Embodiments of the present disclosure are based on a recognition that some processors are configured with instructions to compute logarithms and exponents (i.e. some processors include log and exp circuits). Embodiments of the present disclosure are further based on an insight that the use of the existing log and exp circuits could be extended to compute certain other functions by using the existing log and exp circuits to transform from a Cartesian to a logarithmic domain and vice versa and performing the actual computations of the functions in the logarithmic domain, which may be computationally easier than performing the computations in the Cartesian domain.

Abstract: In safety-critical computer systems, fault tolerance is an important design requirement. Data buses for on-chip interconnection in these processor-based systems are exposed to risk arising from faults in the interconnect itself or in any of the connected peripherals. To provide sufficient fault tolerance, a safety node is inserted between an upstream master section and a downstream slave section of an on-chip bus hierarchy or network. The safety node provides a programmable timeout monitor for detecting a timeout condition for a transaction. If timeout has occurred, the safety node transmits a dummy response back to the master, assumes the role of a master, and waits for the slave device to respond. Furthermore, the safety node rejects any subsequent requests by any of the masters on the upstream section by transmitting a dummy response to those subsequent requests, thus enabling these masters to avoid deadlock or stall.