Tue, 26 May 2015 08:00:00 EDTA circuit includes first and second transconductance stages that generate first and second currents, respectively, in response to an input signal. A current combiner circuit selectively couples the first current to a first output, selectively couples the second current to the first output, selectively couples the first current to a second output, and selectively couples the second current to the second output. In response to the first current being coupled to both the first and second outputs, the current combiner circuit couples the second current to both the first and second outputs. In response to the first current being decoupled from the second output, the current combiner circuit decouples the second current from both the first and second outputs. In response to the first current being decoupled from the first output, the current combiner circuit decouples the second current from both the first and second outputs.
Tue, 26 May 2015 08:00:00 EDTAn electronic oscillator circuit has a first oscillator, for supplying a first oscillation signal, a second oscillator, for supplying a second oscillation signal, a first controller for delivering the first control signal as a function of a phase difference between a first controller input and a second controller input of the first controller; a second controller for delivering the second control signal as a function of a phase difference between a first controller input of the second controller and a second controller input of the second controller; a resonator; at least a second resonance frequency, with a first phase shift dependent on the difference between the frequency of a second exciting signal and the second resonance frequency and processing means, for receiving the first oscillator signal and the second oscillator signal, determining their mutual proportion, looking up a frequency compensation factor in a prestored table and outputting a compensated oscillation signal.
Tue, 26 May 2015 08:00:00 EDTAn apparatus is disclosed that includes a first cross-coupled transistor pair, a second cross-coupled transistor pair, at least one capacitance unit, and an inductive unit. The first cross-coupled transistor pair and second cross-coupled transistor pair are coupled to a pair of first output nodes and a pair of second output nodes, respectively. The at least one capacitance unit is coupled to at least one of the pair of first output nodes and the pair of second output nodes. The inductive unit is coupled to the first cross-coupled transistor pair at the first output nodes and coupled to the second cross-coupled transistor pair at the second output nodes. The inductive unit generates mutual magnetic coupling between one of the first output nodes and one of the second output nodes and between the other of the first output nodes and the other of the second output nodes.
Tue, 26 May 2015 08:00:00 EDTA crystal controlled oscillator includes a crystal package and an IC chip board that includes an IC chip integrating an oscillator circuit. The crystal package includes a first container, a crystal resonator, a lid body, and an external terminal at an outer bottom surface of the first bottom wall layer of the first container. The IC chip integrates an oscillator circuit disposed at an outer bottom surface of the first bottom wall layer of the crystal package. The oscillator circuit connects to the lower side excitation electrode of the crystal resonator from the external terminal to an input side with high impedance. The oscillator circuit connects to the upper side excitation electrode to an output side with low impedance. The upper side excitation electrode is a shielding electrode of the crystal resonator.
Tue, 26 May 2015 08:00:00 EDTA method of controlling an integrated circuit chip including first and second clock sources, the first clock source being more thermally stable and having a higher power consumption, the integrated circuit chip being operable in a first mode in which the first clock source is inactive and the second clock source active and in a second mode in which the first and second clock sources are active, the method including operating the integrated circuit chip in the first mode; taking a measurement indicative of temperature; if the measurement indicates that the temperature is outside of a temperature band: activating the first clock source so as to operate the integrated circuit chip in the second mode; recalibrating the second clock source against the first clock source; and following the recalibration, deactivating the first clock source so as to return the integrated circuit chip to the first mode.
Tue, 26 May 2015 08:00:00 EDTA phase locked loop (PLL) includes a first loop, a second loop, and a lock detector. The first loop locks a feedback signal having a frequency equal to a fraction of a frequency of an output signal to a reference signal in phase. The first loop has a first bandwidth. The second loop locks the feedback signal to the reference signal in frequency and has a second bandwidth. The first bandwidth is higher than the second bandwidth. The lock detector is coupled to the second loop and increases the second bandwidth in response to detecting that the feedback signal is not locked to the reference signal.
Tue, 26 May 2015 08:00:00 EDTArrays of resonator sensors include an active wafer array comprising a plurality of active wafers, a first end cap array coupled to a first side of the active wafer array, and a second end cap array coupled to a second side of the active wafer array. Thickness shear mode resonator sensors may include an active wafer coupled to a first end cap and a second end cap. Methods of forming a plurality of resonator sensors include forming a plurality of active wafer locations and separating the active wafer locations to form a plurality of discrete resonator sensors. Thickness shear mode resonator sensors may be produced by such methods.
Tue, 19 May 2015 08:00:00 EDTA vibration element includes a piezoelectric substrate including a vibrating section and a thick section having a thickness larger than that of the vibrating section. The thick section includes a first thick section provided along a first outer edge of the vibrating section, a second thick section provided along a second outer edge, and a third thick section provided along another first outer edge. An inclined outer edge section that intersects with each of an X axis and a Z′ axis is provided in a tip section of the piezoelectric substrate.
Tue, 19 May 2015 08:00:00 EDTAn enhanced negative resistance voltage controlled oscillator (VCO) circuit is provided, in which a parallel connection of a capacitor and a resistor configured to provide frequency-dependent transconductance is present across source nodes of a first pair of field effect transistors in which gate nodes and drain nodes are cross-coupled. The source nodes of the first pair of field effect transistors are electrically shorted to drain nodes of a second pair of field effect transistors of which the gate nodes are electrically shorted to the gate nodes of the first pair of field effect transistors. The parallel connection of the capacitor and the resistor includes a parallel connection of a capacitor and a resistor such that the net transconductance of the first pair of field effect transistors is less at low frequencies where thermal noise and flicker noise are dominant part of the phase noise than at the operational frequency range.
Tue, 19 May 2015 08:00:00 EDTThe switching element is provided in a state of being electromagnetically coupled to the cavity resonator of the high frequency oscillator; the bias voltage applying terminal is connected to one electrode of the switching element; another electrode of the switching element is electrically connected to the cavity resonator (the anode shell in FIG. 1); the metal plate having a size enough for reflecting an electric wave to be transmitted before and after the switching element in a high-frequency manner is provided at any one end of the switching element; and by applying a bias voltage to the switching element and varying that, a reactance of the switching element is changed and a resonance frequency of the cavity resonator is varied. By this method, an oscillation frequency can be varied greatly relative to a small change in a bias voltage.
Tue, 19 May 2015 08:00:00 EDTA ring-oscillator-based on-chip sensor (OCS) includes a substrate having a semiconductor surface upon which the OCS is formed. The OCS includes an odd number of digital logic stages formed in and on the semiconductor surface including a first stage and a last stage each including at least one NOR gate including a first gate stack and/or a NAND gate including a second gate stack. A feedback connection is from an output of the last stage to an input of the first stage. At least one discharge path including at least a first p-channel metal-oxide semiconductor (PMOS) device is coupled between the first gate stack and a ground pad, and/or at least one charge path including at least a first n-channel metal-oxide semiconductor (NMOS) device is coupled between the second gate stack a power supply pad.
Tue, 19 May 2015 08:00:00 EDTAn integrated oscillator circuit comprises an oscillator configured to be switched between a first frequency and a second frequency. A switching circuit receives an input representing a target frequency and switches the oscillator between the first and second frequencies at intervals determined by the input, so as to cause the average output frequency of the oscillator to approximate the target frequency.
Tue, 12 May 2015 08:00:00 EDTA ring oscillator circuit causing a pulse signal to circulate around a circle to which an even number of inverting circuits are connected in a ring, wherein one of the inverting circuits is a first starting inverting circuit, which drives a first pulse signal according to a control signal, another of the inverting circuits is a second starting inverting circuit, which drives a second pulse signal based on a leading edge of the first pulse signal, still another is a third starting inverting circuit, which drives a third pulse signal based on the leading edge of the first pulse signal after the second pulse signal is driven, and the first to third starting inverting circuits are arranged within the circle of the inverting circuits in order of the third, second, and first pulse signals in traveling directions of the pulse signals.
Tue, 12 May 2015 08:00:00 EDTThis invention discloses a crystal oscillator, in which by appropriately designing the gain of an amplifier to achieve high trans-conductance and low power consumption. This crystal oscillator includes a first pad, coupled to a first node of a crystal, for receiving a crystal oscillating signal outputted from the crystal; an amplifier, coupled to the first pad, for amplifying the crystal oscillating signal to generate an amplifying signal; an inverter, coupled to the amplifier, for inverting the amplifying signal; and a second pad, coupled to a second node of the crystal, for outputting an oscillating signal to the crystal.
Tue, 12 May 2015 08:00:00 EDTA current output control device is provided that includes: a current cell array section including plural current cell circuits that are each connected in parallel between a first terminal (power source) and a second terminal (ground) that connect between the first terminal and the second terminal in by operation ON so as to increase control current flowing between the first terminal and the second terminal; and a code conversion section (decoder) that generates signals (row codes, column codes) to ON/OFF control current cells so as to change the number of current cells that connect the first terminal and the second terminal according to change in an externally input code and that inputs the generated signals to the current cell array section.
Tue, 05 May 2015 08:00:00 EDTDisclosed are a phase locked loop (PLL) of a digital scheme and a method thereof. More specifically, disclosed are a digital phase locked loop having a time-to-digital converter (TDC), a digital loop filter (DLF), and a digitally controlled oscillator (DCO), and that is designed to have a constant jitter characteristic at all times even though an operating condition of a circuit varies according to a process, voltage, temperature (PVT) change, and a method thereof.
Tue, 05 May 2015 08:00:00 EDTVarious techniques for generating an output clock based on a reference clock. This disclosure relates to generating an output clock signal based on a reference clock signal. In one embodiment, a method includes generating, using information received from a control circuit, an output clock signal using both a first number of edges or an input clock signal and a second, different number of edges of the input clock signal. In this embodiment, the control circuit runs at a frequency that is less than a frequency of the input clock signal. The received information may indicate, for a pulse of the output clock signal, whether the pulse should be generated using the first number of edges or the second number of edges. In some cases, the second number of edges may be the first number of edges plus one. The first and second number of edges may be programmable quantities.
Tue, 05 May 2015 08:00:00 EDTEmbodiments of the present invention provide a temperature compensation method and a crystal oscillator, where the crystal oscillator includes a crystal oscillation circuit unit, a temperature sensor unit, an oscillation controlling unit, a relative temperature calculating unit, and a temperature compensating unit. The temperature sensor unit measures a measured temperature of the crystal oscillation circuit unit; the relative temperature calculating unit obtains a temperature difference between the measured temperature and a reference temperature; the temperature compensating unit obtains a temperature compensation value corresponding to the temperature difference from a temperature-frequency curve; and the oscillation controlling unit generates a frequency control signal, according to a frequency tracked by a communications AFC device and the temperature compensation value, thereby controlling a frequency of the crystal oscillation circuit unit to work on the tracked frequency.
Tue, 05 May 2015 08:00:00 EDTThe invention relates to a method for operating control equipment (1) of a resonance circuit (2), wherein the control equipment (1) comprises at least two circuit elements (8, 9) connected in series, in particular each comprising a recovery diode (13, 14) connected in parallel, between which a connection (6) of the resonance circuit (2) is connected. According to the invention, the circuit elements (8, 9) are actuated as a function of the voltage detected at the connection (6). The invention further relates to control equipment (1) of a resonance circuit (2).
Tue, 05 May 2015 08:00:00 EDTAn injection locking oscillator (ILO) comprising a tank circuit having a digitally controlled capacitor bank, a cross-coupled differential transistor pair coupled to the tank circuit, at least one signal injection node, and at least one output node configured to provide an injection locked output signal; a digitally controlled injection-ratio circuit having an injection output coupled to the at least one signal injection node, configured to accept an input signal and to generate an adjustable injection signal applied to the at least one injection node; and, an ILO controller connected to the capacitor bank and the injection-ratio circuit configured to apply a control signal to the capacitor bank to adjust a resonant frequency of the tank circuit and to apply a control signal to the injection-ratio circuit to adjust a signal injection ratio.
Tue, 05 May 2015 08:00:00 EDTAn oscillator includes: a piezoelectric material to vibrate; a first inverting amplifier; a second inverting amplifier; a first output electrode to apply an output signal of the first inverting amplifier to the piezoelectric material; a second output electrode to apply an output signal of the second inverting amplifier to the piezoelectric material; a first input electrode to receive a voltage signal generated by the piezoelectric material and output the voltage signal to the first inverting amplifier; and a second input electrode to receive the voltage signal and output the voltage signal to the second inverting amplifier, wherein the first and second output electrodes are coupled to the piezoelectric material so that faces of the piezoelectric material move in opposite directions, and the first and second input electrodes are coupled to the piezoelectric material so that the voltage signals are input to the first and second input electrodes.
Tue, 05 May 2015 08:00:00 EDTA system is disclosed for a voltage controlled oscillator (“VCO”) having a large frequency range and a low gain. Passive or active circuitry is introduced between at least one VCO cell in the voltage controlled oscillator and the voltage source for the VCO cell which reduces a gain value for the VCO to maintain stability of the system.
Tue, 05 May 2015 08:00:00 EDTA crystal-less clock generator (CLCG) and an operation method thereof are provided. The CLCG includes a first oscillation circuit, a second oscillation circuit, and a control circuit. The first oscillation circuit is controlled by a control signal for generating an output clock signal of the CLCG. The second oscillation circuit generates a reference clock signal. The control circuit is coupled to the first oscillation circuit for receiving the output clock signal and coupled to the second oscillation circuit for receiving the reference clock signal. The control circuit is used to generate the control signal for the first oscillation circuit according to the relationship between the output clock signal and the reference clock signal.
Tue, 05 May 2015 08:00:00 EDTA method, an apparatus, and a computer program product are provided. The apparatus tunes a frequency provided by a VCO. The apparatus determines a relative capacitance change associated with a first frequency and a desired frequency from a look-up table. The apparatus adjusts a capacitor circuit in the VCO based on the determined relative capacitance change determined from the look-up table in order to tune from the first frequency to the desired frequency. The apparatus determines that the frequency provided by the VCO is a second frequency different than the desired frequency after adjusting the capacitor circuit. The apparatus performs an iterative search to further adjust the capacitor circuit when a difference between the second frequency and the desired frequency is greater than a threshold.
Tue, 28 Apr 2015 08:00:00 EDTThe present invention proposes a digital system and method of measuring (estimating) non-energy parameters of the signal (phase, frequency and frequency rate) received in additive mixture with Gaussian noise. The first embodiment of the measuring system consists of a PLL system tracking variable signal frequency, a block of NCO full phase computation (OFPC), a block of signal phase primary estimation (SPPE) and a first type adaptive filter filtering the signal from the output of SPPE. The second embodiment of the invention has no block SPPE, and NCO full phase is fed to the input of a second type adaptive filter. The present invention can be used in receivers of various navigation systems, such as GPS, GLONASS and GALILEO, which provide precise measurements of signal phase at different rates of frequency change, as well as systems using digital PLLs for speed measurements.
Tue, 28 Apr 2015 08:00:00 EDTA memristor-based emulator including a memristor circuit for use in digital modulation that includes a first current feedback operational amplifier (CFOA) having multiple terminals in communication with a capacitor Cd and in further communication with a resistor Ri. A second CFOA having multiple terminals is in communication with the first CFOA and is adapted to be in further communication with a voltage vM to provide an input current iM for integration by a capacitor Ci. A nonlinear resistor is in communication with the second CFOA. A third CFOA having multiple terminals is in communication with the nonlinear resistor and is in further communication with the first CFOA and a resistor Rd. The third CFOA and the resistor Rd act as an inverting amplifier associated with the nonlinear resistor to increase a current gain to increase a difference between ON and OFF values of a resistance of a realized memristor.
Tue, 28 Apr 2015 08:00:00 EDTSystems and methods for switching impedance are provided. In some aspects, a system includes first and second impedance elements and an impedance switch module, which includes a third impedance element coupled between the first and second impedance elements and a switch parallel to the third impedance element. The switch is coupled between the first and second impedance elements, and is configured to switch between an open configuration and a closed configuration. An electrical path is completed between the first impedance element and the second impedance element via the first switch in the closed configuration. The electrical path is not completed in the open configuration. A total impedance of the first impedance element, the second impedance element, and the impedance switch module is varied based on the switching between the open configuration and the closed configuration.
Tue, 28 Apr 2015 08:00:00 EDTAn integrated structure of compound semiconductor devices is disclosed. The integrated structure comprises from bottom to top a substrate, a first epitaxial layer, an etching-stop layer, a second epitaxial layer, a sub-collector layer, a collector layer, a base layer, and an emitter layer, in which the first epitaxial layer is a p-type doped layer, the second epitaxial layer is an n-type graded doping layer with a gradually increased or decreased doping concentration, and the sub-collector layer is an n-type doped layer. The integrated structure can be used to form an HBT, a varactor, or an MESFET.
Tue, 28 Apr 2015 08:00:00 EDTAn oscillation device is provided. The oscillation device includes: a main circuit portion, a heating unit, first and second crystal units, first and second oscillator circuits, a frequency difference detector, a first addition unit, an integration circuit unit, a circuit unit configured to control an electric power to be supplied to the heating unit, a compensation value obtaining unit, and a second addition unit. The compensation value obtaining unit is configured to obtain a frequency compensation value for compensating an output frequency of the main circuit portion based on an integrated value output from the integration circuit unit, and based on a change in the clock signal due to a difference between the temperature of the atmosphere and the temperature setting value of the heating unit. The second addition unit is configured to add the frequency compensation value to a frequency setting value.
Tue, 28 Apr 2015 08:00:00 EDTAn oscillator module includes a first MOS transistor and a capacitor. The capacitor is coupled between a gate and source of the first MOS transistor. The drain of the first MOS transistor receives a first bias current and generates an oscillating output signal. A switching circuit operates in response to the oscillating output signal to selective charge and discharge the capacitor. A current sourcing circuit is configured to generate the bias current. The current sourcing circuit includes a second MOS transistor which has an identical layout to the first MOS transistor and receives a second bias current. A resistor is coupled between a gate and source of the second MOS transistor. The current sourcing circuit further includes a current mirror having an input configured to receive a reference current passing through the resistor and generate the first and second bias currents.
Tue, 28 Apr 2015 08:00:00 EDTAn oscillator configured to oscillate an electromagnetic wave, including: a negative resistance device; a microstrip resonator configured to determine an oscillation frequency of an electromagnetic wave excited by the negative resistance device; a resistance device and a capacitance device, which form a low-impedance circuit configured to suppress parasitic oscillation; and a strip conductor configured to connect the capacitance device of the low-impedance circuit and the microstrip resonator to each other, in which an inductance L of the strip conductor and a capacitance C of the microstrip resonator produce a resonance frequency of ½π√LC, and ¼ of an equivalent wavelength of the resonance frequency is larger than a distance between the negative resistance device and the resistance device of the low-impedance circuit via the strip conductor, is provided.
Tue, 28 Apr 2015 08:00:00 EDTAn atomic oscillator includes: a gas cell which includes two window portions having a light transmissive property and in which metal atoms are sealed; a light emitting portion that emits excitation light to excite the metal atoms in the gas cell; a light detecting portion that detects the excitation light transmitted through the gas cell; a heater that generates heat; and a connection member that thermally connects the heater and each window portion of the gas cell to each other.
Tue, 28 Apr 2015 08:00:00 EDTAn oscillator outputs a control signal to suppress an influence caused by temperature characteristic of f1 based on a differential signal corresponding to difference between an oscillation output f1 of a first oscillator circuit and an oscillation output f2 of a second oscillator circuit treated as a temperature detection value. A switching unit switches between a first state and a second state. The first state is a state where a first connecting end and a second connecting end are connected to a storage unit for access from an external computer to the storage unit. The second state is a state where the first connecting end and the second connecting end are connected to a first signal path and a second signal path such that the respective f1 and f2 are retrieved from the first connecting end and the second connecting end to an external frequency measuring unit.
Tue, 28 Apr 2015 08:00:00 EDTThe present invention discloses an Oven Controlled Crystal Oscillator and a manufacturing method thereof. The Oven Controlled Crystal Oscillator comprises a thermostatic bath, a heating device, a PCB and a signal generating element, where the signal generating element is used for generating a signal of a certain frequency, the heating device, the PCB and the signal generating element are mounted in the thermostatic bath, the signal generating element is mounted in a groove formed on one side of the PCB, while the heating device is mounted against the other side of the PCB that is opposite to the groove. The signal generating element may be a passive crystal resonator or an active crystal oscillator. The Oven Controlled Crystal Oscillator according to the invention is advantageous for a small volume and a high temperature control precision.
Tue, 28 Apr 2015 08:00:00 EDTEmbodiments provide a multi-phase voltage controlled oscillator (VCO) that produces a plurality of output signals having a common frequency and different phases. In one embodiment, the VCO may include a passive conductive structure having a first ring and a plurality of taps spaced around the first ring. The VCO may further include a capacitive load coupled to the passive conductive structure, one or more feedback structures coupled between a pair of opposing taps of the plurality of taps, and one or more current injection devices coupled between a pair of adjacent taps of the plurality of taps.
Tue, 28 Apr 2015 08:00:00 EDTA digitally-controlled oscillator includes a base frequency generator having an odd number of base inverters connected end-to-end to generate an output signal that oscillates at a predetermined frequency and a frequency-adjusting unit connected to the base frequency generator. The frequency-adjusting unit includes a first string of switchable inverters connected in series with each other, the switchable inverters having sizes that decrease from an input end of the first string to the output end of the first string.
Tue, 28 Apr 2015 08:00:00 EDTThe invention concerns an oscillator generating a wave composed of a frequency of on the order of terahertz from a beat of two optical waves generated by a dual-frequency optical source. The oscillator includes a modulator the transfer function of which is non-linear for generating harmonics with a frequency of less than one terahertz for each of the optical waves generated by the dual-frequency optical source, an optical detector able to detect at least one harmonic for each of the optical waves generated by the dual-frequency optical source and transforming the harmonics detected into an electrical signal, a phase comparator for comparing the electrical signal with a reference electrical signal, and a module for controlling at least one element of the dual-frequency optical source with a signal obtained from the signal resulting from the comparison.
Tue, 28 Apr 2015 08:00:00 EDTAn integrated circuit (10) has an internal RC-oscillator (20) for providing an internal clock signal (CLI) having an adjustable oscillator frequency. The integrated circuit (10) further comprises terminals (101, 102) for connecting an external LC tank (30) having a resonance frequency and a calibration circuit (40) which is configured to adjust the oscillator frequency based on the resonance frequency of the LC tank (30) connected during operation of the integrated circuit (10). An internal auxiliary oscillator (46) is connected to the terminals (101, 102) in a switchable fashion and is configured to generate an auxiliary clock signal (CLA) based on the resonance frequency. The calibration circuit (40) comprises a frequency comparator (47) which is configured to determine a trimming word (TRW) based on a frequency comparison of the internal clock signal (CLI) and the auxiliary clock signal (CLA). The LC tank (30) to be connected is an antenna for receiving a radio signal.
Tue, 28 Apr 2015 08:00:00 EDTA digitally controlled oscillator has a high-order ΔΣ modulator configured to be of at least an order higher than a first order and configured to input a digital control signal and output a pseudorandom digital output signal, a first-order ΔΣ modulator configured to input the pseudorandom digital output signal and generate a control pulse signal including a pulse width corresponding to the pseudorandom digital output signal, a low pass filter configured to pass a low frequency component of the control pulse signal, and an oscillator configured to generate a high-frequency output signal whose frequency is controlled based on the control pulse signal outputted by the low pass filter so as to be a frequency corresponding to the digital control signal.
Tue, 28 Apr 2015 08:00:00 EDTThere are provided an accumulator-type fractional N-PLL synthesizer for suppressing the fractional spurious caused by periodically switching a frequency division number of a fractional frequency divider, and a control method thereof. In an accumulator-type fractional N-PLL synthesizer (100), a pulse signal proportional to a fractional phase error occurring between a reference signal and an output signal of a fractional divider (112) for feeding back an output of a VCO (115) of an output stage to a preceding stage is generated using an error signal from an accumulator (120). Through the use of the pulse signal, pulse widths of a UP signal and a DN signal output from a phase detector (140) are controlled so as to reduce a fractional phase error occurring between the UP signal and the DN signal. Thus, the fractional spurious caused by periodically switching the frequency division number of the fractional divider (112) is suppressed.
Tue, 28 Apr 2015 08:00:00 EDTA self-feedback random generator comprises a digital-to-analog converter, a digital oscillator, a frequency-modulating unit and a first D-type flip-flop. The digital-to-analog converter receives a digital random-code signal and the digital random-code signal is converted to corresponding analog random signal. The frequency-modulating unit modulates frequency of first digital oscillating signal so as to increase random of frequency of first digital oscillating signal according to voltage value of the analog random signal, and accordingly outputs a second digital oscillating signal. The first D-type flip-flop receives the second digital oscillating signal and a clock signal, and reads the second digital oscillating signal through utilizing the clock signal so as to outputs the digital random-code signal, wherein frequency of the clock signal is smaller than frequency of the first digital oscillating signal, and random of frequency of the second digital oscillating signal corresponds to random of the digital random-code signal.
Tue, 28 Apr 2015 08:00:00 EDTA phase locked loop includes a voltage controlled oscillator and a frequency divider or frequency multiplier. The voltage controlled oscillator and the frequency divider/multiplier are coupled together in a stacked configuration. A drive current is supplied to the voltage controlled oscillator. The drive current passes from the voltage controlled oscillator to the frequency divider/multiplier, thereby driving the frequency divider/multiplier with the same drive current that was supplied to the voltage controlled oscillator.
Tue, 21 Apr 2015 08:00:00 EDTAn oscillating device includes a temperature compensated oscillator that compensates a frequency temperature characteristic in a temperature compensation range including apart of a first temperature range, and a temperature control circuit that includes a heater and controls a temperature of a quartz crystal resonator of the temperature compensated oscillator into a second temperature range included in the temperature compensation range. Further, the temperature compensation range of the temperature compensated oscillator may include a part of the first temperature range in which compensation can be performed by first-order approximation.
Tue, 21 Apr 2015 08:00:00 EDTA resonator element includes a substrate vibrating in a thickness-shear vibration mode, a first excitation electrode disposed on one principal surface of the substrate, and has a shape obtained by cutting out four corners of a quadrangle, and a second excitation electrode disposed on the other principal surface of the substrate, and a ratio (S2/S1) between the area S1 of the quadrangle and the area S2 of the first excitation electrode fulfills 87.7%≦(S2/S1)
Tue, 21 Apr 2015 08:00:00 EDTA resonator element includes a substrate including a first principal surface and a second principal surface respectively forming an obverse surface and a reverse surface of the substrate, and vibrating in a thickness-shear vibration mode, a first excitation electrode disposed on the first principal surface, and a second excitation electrode disposed on the second principal surface, and being larger than the first excitation electrode in a plan view, the first excitation electrode is disposed so as to fit into an outer edge of the second excitation electrode in the plan view, and the energy trap confficient M fulfills 15.5≦M≦36.7.
Tue, 21 Apr 2015 08:00:00 EDTThe present disclosure relates to nanoresonator oscillators or NEMS (nanoelectromechanical system) oscillators. A circuit for measuring the oscillation frequency of a resonator is provided, comprising a first phase-locked feedback loop locking the frequency of a controlled oscillator at the resonant frequency of the resonator, this first loop comprising a first phase comparator. Furthermore, a second feedback loop is provided which searches for and stores the loop phase shift introduced by the resonator and its amplification circuit when they are locked at resonance by the first loop. The first and the second loops operate during a calibration phase. A third self-oscillation loop is set up during an operation phase. It directly links the output of the controllable phase shifter to the input of the resonator. The phase shifter receives the phase-shift control stored by the second loop.
Tue, 21 Apr 2015 08:00:00 EDTA method in a circuit comprises providing a first clock by a resistor-capacitor (RC) oscillator; demodulating a plurality of input signals to form a plurality of demodulated input signals; discriminating frequency ranges of the plurality of demodulated input signals according to the first clock; determining whether a first predetermined number of consecutive demodulated input signals among the plurality of demodulated input signals fall into a first predetermined frequency range; triggering a crystal oscillator to provide a second clock to calibrate the first clock if the first predetermined number of consecutive input signals fall into the first predetermined frequency range.
Tue, 14 Apr 2015 08:00:00 EDTA circuit for a single differential-inductor oscillator with common-mode resonance may include a tank circuit formed by coupling a first inductor with a pair of first capacitors; a cross-coupled transistor pair coupled to the tank circuit; and one or more second capacitors coupled to the tank circuit and the cross-coupled transistors. The single differential-inductor oscillator may be configured such that a common mode (CM) resonance frequency (FCM) associated with the single differential-inductor oscillator is at twice a differential resonance frequency (FD) associated with the single differential-inductor oscillator.
Tue, 14 Apr 2015 08:00:00 EDTThe present invention provides a digitally controlled, current starved, pulse width modulator (PWM). In the PWM of the present invention, the amount of current from the voltage source to the ring oscillator is controlled by the proposed header circuit. By changing the header current, the pulse width of the switching signal generated at the output of the ring oscillator is dynamically controlled, where the duty cycle can vary between 50% and 90%. A duty cycle to voltage converter is used to ensure the accuracy of the system under process, voltage, and temperature (PVT) variations. The proposed pulse width modulator is appropriate for dynamic voltage scaling systems due to the small on-chip area and high accuracy under process, voltage, and temperature variations.
Tue, 14 Apr 2015 08:00:00 EDTAccording to one embodiment, a first oscillator has an oscillation frequency that is changed depending on a temperature. A second oscillator has different temperature characteristics from the first oscillator. An on-chip heater heats the first oscillator and the second oscillator. A counter counts a first oscillation signal of the first oscillator. An ADPLL generates a third oscillation signal on the basis of a second oscillation signal of the second oscillator and corrects the frequency of the third oscillation signal on the basis of a count value of the counter.