Abstract: An amplitude limiter circuit includes an inductor and a shunt circuit. The inductor has a first terminal connected to an input node. The shunt circuit is connected to a second terminal of the inductor and also is connected to a low impedance node. If an overvoltage condition forms on the input node, the shunt circuit forms an overvoltage current path from the input node, through the inductor, through the shunt circuit and to low impedance node.

Abstract: A multi-phase power converter includes a plurality of power channels arranged in parallel to drive an output of the power converter, and a channel selection circuit. Each of the power channels includes a driver, a feedback control circuit coupled to an output of the driver, and a comparator coupled to the feedback control circuit. The channel selection circuit is coupled to the feedback control circuit of each of the power channels. The channel control circuit is configured to: select a different specific one of the power channels to activate in each of a plurality of phases, and introduce an offset voltage into each of the feedback control circuits, except the feedback control circuit of the specific one of the power channels. The feedback control circuit is configured to apply the offset to bias driver output feedback voltage away from a threshold voltage at which the power channel is activated.

Abstract: A vehicle tire monitoring methodology is based on embedding into a tire at least one tire inductor coil with multiple circumferential windings. A tire condition that causes deformation of the tire, causes deformation of the tire inductor coil. A tire condition (such as pressure, speed, damage or deterioration) can be monitored by acquiring tire coil response measurements corresponding to an inductive response to the tire condition that causes deformation of the tire, and thereby deformation of the tire inductor coil, and then converting the tire coil response into data representing the tire condition. Multiple circumferential tire inductor coils can be embedded (such as into the tread and/or sidewalls), so that tire monitoring can involve acquiring respective tire coil responses corresponding to a tire condition that causes differential tire coil responses (such as steering direction), which can be converted into data representing the tire condition.

Abstract: Methods and apparatus for operating a DC-to-DC voltage converter that has a power stage that includes at least one switching transistor. The output voltage of the DC-to-DC voltage converter is monitored. If the output voltage drops below a lower output voltage threshold, a series of drive pulses is provided to the at least one switching transistor to commence switching of the at least one switching transistor. If the output voltage rises above an upper output voltage threshold, a random number of additional drive pulses is provided to the at least one switching transistor and then the provision of drive pulses to the at least one switching transistor is ceased.

Abstract: A tire pressure sensor has an RFID (radio frequency identification) device having a parallel resonant circuit including an inductor and a first capacitor for generating a first radio frequency (RF) signal for transmission to a reader circuit, and a second capacitor coupled across the parallel resonant circuit by a first switch in a first position and generating a second RF signal for transmission to the reader circuit. A capacitive pressure sensor is coupled across the parallel resonant circuit by the first switch in a second position for generating a third frequency RF signal for transmission to the reader, wherein a difference in frequency between the first and third RF signals is indicative of a pressure of a tire.

Abstract: In described examples, an apparatus includes: a counter configured to receive a reference clock signal and having a next state input and a current state output; a multiplexer coupled to the next state input of the counter, configured to output one of an incremented next state value and a corrected next state count value responsive to a count correction select control signal; a seconds reference circuit coupled to the current state output of the counter, configured to output a seconds reference signal; an incrementer coupled to the current state output of the counter, configured to output the incremented next state value; and a calibration compensation circuit coupled to a compensate up down input signal and to the current state output of the counter, configured to output the corrected next state count value and the count correction select control signal.

Abstract: A circuit, system, and method for tracking energy use in a electronic circuit. A circuit includes a DC-DC converter and a comparator. The DC-DC converter is configured to maintain a desired output voltage by switching energy to an energy storage device based on an output voltage of the energy storage device. The DC-DC converter includes an output driver configured to source current to the energy storage device. The comparator is coupled to the DC-DC converter. The comparator is configured to identify a drive state of the output driver, and to generate a signal indicative of amount of energy transferred from the DC-DC converter to a load circuit. The signal corresponds to the identified drive state.

Abstract: Methods and apparatus for a low energy accelerator processor architecture with short parallel instruction word. An integrated circuit includes a system bus having a data width N, where N is a positive integer; a central processor unit coupled to the system bus and configured to execute instructions retrieved from a memory coupled to the system bus; and a low energy accelerator processor coupled to the system bus and configured to execute instruction words retrieved from a low energy accelerator code memory, the low energy accelerator processor having a plurality of execution units including a load store unit, a load coefficient unit, a multiply unit, and a butterfly/adder ALU unit, each of the execution units configured to perform operations responsive to op-codes decoded from the retrieved instruction words, wherein the width of the instruction words is equal to the data width N. Additional methods and apparatus are disclosed.

Abstract: An RF or other high frequency transceiver including a loopback reference channel for measurement of an absolute power level. A transmit channel in the transceiver includes a programmable power amplifier that can be controlled to operate at a selected power level, and a receive channel including a receive amplifier, mixers, filters, and analog-to-digital converters. The loopback reference channel includes a self-biased amplifier, followed by a series of buffers that generate a square wave from the received signal, and an attenuator applying an attenuation gain to the square wave. The transmit power at a programmed power level can be calculated from ratios of a measured power level of a transmitted signal as received by the receive channel to the measured power level of the transmitted signal using the loopback reference channel.

Abstract: An apparatus includes: a voltage regulator that outputs a voltage responsive to an enable signal; a power managed domain coupled to the voltage regulator and including a clock generator configured to output a clock signal from the clock generator; and an always on domain. The always on domain receives the clock signal. The always on domain includes a finite state machine coupled to receive the clock signal and receiving a shutdown request signal. The finite state machine is configured to output a signal to control power to the power managed domain and to disable the clock generator, responsive to the shutdown request signal. The finite state machine receives an asynchronous wake signal, and circuitry in the always on domain is coupled to enable power to the power managed domain and to the clock generator, responsive to the asynchronous wake input signal.

Abstract: Disclosed examples include an RF transponder circuit with signal input nodes, a rectifier circuit with a power transistor and a current mirror circuit to generate a rectifier mirror current signal, a limiter circuit with a limiter transistor and a current mirror circuit to generate a limiter mirror current signal, and a demodulator circuit to demodulate an amplitude shift keying (ASK) RF signal received at the signal input nodes according to the rectifier and limiter mirror current signal to generate a binary demodulator data signal representing the presence or absence of a threshold amount of energy in the RF signal.

Abstract: In a switched mode inductive DCDC converter having a first mode that conducts a first current path through an inductor and through a first switch, and a second mode that conducts a second current path through the inductor and through a second switch, a detecting component detects a parameter. The detecting component outputs a biasing signal extend the turn OFF time of one of the switches in order to decrease a voltage build up on the other switch.

Abstract: Described examples include DC to DC converters and systems with switching circuitry formed by four series-connected switches, inductors connected between the ends of the switching circuitry and corresponding output nodes, and with a flying capacitor coupled across interior switches of the switching circuitry and a second capacitor coupled across the ends of the switching circuitry. A control circuit operates the switching circuit to control a voltage signal across the output nodes using a first clock signal and a phase shifted second clock signal to reduce output ripple current and enhance converter efficiency using valley current control. The output inductors are wound on a common core in certain examples.

Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: Circuitry includes: a resonant circuit for receiving a radio frequency signal; a rectifier outputting a first rectified signal matching a portion of the radio frequency signal and a second rectified signal having portion that matches the radio frequency signal and is out of phase with the first rectified signal; a clock regenerator circuit outputting a clock waveform corresponding to the first and second rectified signals; an oscillator timing circuit forming a first sloped waveform having a linear slope and a second sloped waveform having a linear slope, and comparators to compare the first sloped waveform and the second sloped waveform. The oscillator timing circuit outputs a master clock signal having transitions when the first and the second sloped waveform have equal magnitudes. A pluck pulse generator forms a pulse of a predetermined length when the master clock signal transitions.

Abstract: An integrated circuit contains three thin film resistors over a dielectric layer. The first resistor body includes only a bottom thin film layer and the first resistor heads include the bottom thin film layer, a middle thin film layer and a top thin film layer. The second resistor body and heads include all three thin film layers. The third resistor body does not include the middle thin film layer. The three resistors are formed using two etch masks.

Abstract: An RFID transponder having an analog front end receiver having an attenuator coupled to receive an RF-signal from an antenna and to attenuate the RF-signal, an amplifier having a fixed amplifier gain and being coupled to receive and to amplify the attenuated RF-signal and a control unit coupled to control a gain of the attenuator, wherein the control unit is configured to control the attenuator gain in response to a level of the amplified RF-signal, the control unit is configured to have a plurality of predetermined states causing the attenuator to increase (step-up) or to decrease (step-down), its gain by a predefined step size, wherein the step size of a step-up is equal to or smaller than the step size of a step-down and wherein the control unit is further configured to switch, upon reaching or exceeding a predefined threshold value, from a first to a second state having a smaller step size and causing the attenuator to change the gain such that the slope of the RF signal inverts and to switch, upon reachi

Abstract: A self-calibrating shared-component dual synthesizer includes, for example, two frequency synthesizers that are adapted to operate (respectively) in transmit (TX) and receive (RX) modes. Each synthesizer can be selectively arranged to vary and optimize the phase noise in accordance with the TX and RX requirements associated with each mode as well as independently optimized for flexible low area floorplan to achieve low power, spectral fidelity and reduced test time, low cost built in self-calibration. The two frequency synthesizers are also adapted to provide a built-in self-test signals used for intermodulation testing and calibration.

Abstract: A level shifter circuit has a plurality of channels for providing signals to a capacitive load and has circuits for sharing charge stored in the capacitive load between the channels. A first pair of channel clock generating circuits are coupled respectively to a first pair of channels. A second pair of channel clock generating circuits are coupled respectively to a second pair of channels. A pair of switches couple the first pair of channels together and the second pair of channels together, respectively, for sharing charge between the channels. A single resistor is coupled in circuit with all of the channels for controlling a slope of charge sharing between channels.

Abstract: A start-up circuit for a reference circuit such as a bandgap reference circuit. The start-up circuit includes a diode-connected metal-oxide-semiconductor (MOS) transistor connected between a power supply node and a start-up node that is connected in turn to the gate of a current control MOS transistor in the reference circuit. The diode-connected MOS transistor and the current control MOS transistor are matched with one another. To start up the reference circuit, current is conducted through the diode-connected MOS transistor to set the gate voltage of the current control transistor at a threshold voltage below the power supply voltage. Current conducted by the current control transistor initiates operation of the bandgap reference circuit, and disables the start-up circuit.