Evdokia Menelaou
Aug 8, 2012; 32:10925-10939
BehavioralSystemsCognitive

Hello, Currently i am designing a 96MHZ crystal oscillator using pierce topology and also I use for amplitude gain control circuit for regulation. The problem is when i run a PSS + Pnoise i get these warnings :

WARNING (CMI-2375): M2: Vgs has exceeded the oxide breakdown voltage of `vbox' = 6 V.
WARNING (CMI-2375): M4: Vgs has exceeded the oxide breakdown voltage of `vbox' = 6 V.
WARNING (CMI-2377): M4: Vgd has exceeded the oxide breakdown voltage of `vbox' = 6 V.
WARNING (CMI-2377): M3: Vgd has exceeded the oxide breakdown voltage of `vbox' = 6.6 V.

and also WARNING (CMI-2682): M5: The bulk-drain junction forward bias voltage (1.38154 V) exceeds VjdmFwd'=851.514mV ,The results are now incorrect because the junction current model has been linearized

Note : i am using Supply 1.2 V hence it is not possible to exceed the oxide breakdown. 

So i am asking why i am getting these warnings , it could be a convergence problem and the Results computed are not corrected.

Also when running DC and transient , i don't get these warnings.

Hi *,

I am simulating a 32kHz high Q crystal oscillator with a pulse shaping circuit. I set up a PSS analysis using the Shooting Newton engine. I set a beat frequency of 32k and used the crystal output and ground as reference nodes. After the initial transient the amplitude growth was already pretty much settled such that the shooting iterations could continue the job.

My problem is: In 5...10% of my PVT runs the simulator detects a frequency divider in the initial transient simulation. The output log says:

Frequency divided by 3 at node <xxx>

The Estimated oscillating frequency from Tstab Tran is = 11.0193 kHz .

However, the mentioned node is only part of the control logic and is always constant (but it has some ripples and glitches which are all less than 30uV). These glitches spoil my fundamental frequency (11kHz instead of 32kHz). Sometimes the simulator detects a frequency division by 2 or 3 and the mentioned node <xxx> is different depending on PVT - but the node is always a genuine high or low signal inside my control logic.

How can I tell the simulator that there is no frequency divider and it should only observe the given node pair in the PSS analysis setup to estimate the fundamental frequency? I have tried the following workarounds but none of them worked reliably:

- extended/reduced the initial transient simulation time

- decreased accuracy

- preset override with Euler integration method for the initial transient to damp glitches

- tried different initial conditions

- specified various oscillator nodes in the analysis setup form

By the way, I am using Spectre X (version 21.1.0.389.ISR8) with CX accuracy.

Thanks for your support and best regards

Stephan

Hello everybody,

As you can find in the attached image, I am trying to simulate a Colpitts oscillator. However, using pss analysis it shows a high output power. 

My question is where is the problem of my structure or simulation setup?

Best,

Hello everyone,

For my cross-coupled oscillator design, I have a problem with stability analysis. Based on my achieved results which are attached, where is my design problem?

Best,

https://ibb.co/bgKFP4N

https://ibb.co/3FGRLmV

https://ibb.co/pwSZDSF

This paper deals with an optimal control problem associated to the Kuramoto model describing the dynamical behavior of a network of coupled oscillators. Our aim is to design a suitable control function allowing us to steer the system to a synchronized configuration in which all the oscillators are aligned on the same phase. This control is computed via the minimization of a given cost functional associated with the dynamics considered. For this minimization, we propose a novel approach based on the combination of a standard Gradient Descent (GD) methodology with the recently-developed Random Batch Method (RBM) for the efficient numerical approximation of collective dynamics. Our simulations show that the employment of RBM improves the performances of the GD algorithm, reducing the computational complexity of the minimization process and allowing for a more efficient control calculation.

We construct semiglobal singular spacetimes for the Einstein equations coupled to a massless scalar field. Consistent with the heuristic analysis of Belinskii, Khalatnikov, Lifshitz or BKL for this system, there are no oscillations due to the scalar field. (This is much simpler than the oscillatory BKL heuristics for the Einstein vacuum equations.) Prior results are due to Andersson and Rendall in the real analytic case, and Rodnianski and Speck in the smooth near-spatially-flat-FLRW case. Similar to Andersson and Rendall we give asymptotic data at the singularity, which we refer to as final data, but our construction is not limited to real analytic solutions. This paper is a test application of tools (a graded Lie algebra formulation of the Einstein equations and a filtration) intended for the more subtle vacuum case. We use homological algebra tools to construct a formal series solution, then symmetric hyperbolic energy estimates to construct a true solution well-approximated by truncations of the formal one. We conjecture that the image of the map from final data to initial data is an open set of anisotropic initial data.

The characterization of phase dynamics in coupled oscillators offers insights into fundamental phenomena in complex systems. To describe the collective dynamics in the oscillatory system, order parameters are often used but are insufficient for identifying more specific behaviors. We therefore propose a topological approach that constructs quantitative features describing the phase evolution of oscillators. Here, the phase data are mapped into a high-dimensional space at each time point, and topological features describing the shape of the data are subsequently extracted from the mapped points. We extend these features to time-variant topological features by considering the evolution time, which serves as an additional dimension in the topological-feature space. The resulting time-variant features provide crucial insights into the time evolution of phase dynamics. We combine these features with the machine learning kernel method to characterize the multicluster synchronized dynamics at a very early stage of the evolution. Furthermore, we demonstrate the usefulness of our method for qualitatively explaining chimera states, which are states of stably coexisting coherent and incoherent groups in systems of identical phase oscillators. The experimental results show that our method is generally better than those using order parameters, especially if only data on the early-stage dynamics are available.

A wristwatch, which comprises an atomic oscillator comprising a system for detecting the beat frequencies obtained by the Raman effect.

A method and system for synchronizing the output signal phase of a plurality of frequency divider circuits in a local-oscillator (LO) or clock signal path is disclosed. The LO path includes a plurality of frequency divider circuits and a LO buffer for receiving a LO signal coupled to the plurality of frequency divider circuits. The method and system comprise adding offset voltage and setting predetermined state to each of the frequency divider circuits; and enabling the frequency divider circuits. The method and system includes enabling the LO buffer to provide the LO signal to the frequency divider circuits after they have been enabled. When the LO signal drives each of the frequency divider circuits, each of the frequency divider circuits starts an operation. Finally the method and system comprise removing the offset voltage from each of the frequency divider circuits to allow them to effectively drive other circuits.

A 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.

A 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.

An 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.

The 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.

A 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.

Embodiments 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.

The 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.

An 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.

An 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.

An 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.

A 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.

A 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.

An 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.

An 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.

Embodiments 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.

Various 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.

A 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.

This 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.

A 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.

An 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.

The 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.

An 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.

A 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.

A 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.

An 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.

Provided is an oscillator including: a MEMS resonator for mechanically vibrating; an output oscillator circuit for oscillating at a resonance frequency of the MEMS resonator to output an oscillation signal; and a MEMS capacitor for changing a capacitance thereof caused by a change in a distance between an anode electrode and a cathode beam according to an environmental temperature.

A surface acoustic wave (SAW) resonator and a SAW oscillator and an electronic apparatus including the resonator are to be provided. A SAW resonator includes: an IDT exciting a SAW using a quartz crystal substrate of Euler angles (−1.5°≦φ≦1.5°, 117°≦θ≦142°, 42.79°≦|ψ|≦49.57°); one pair of reflection units arranged so as allow the IDT to be disposed therebetween; and grooves acquired by depressing the quartz crystal substrate located between electrode fingers. When a wavelength of the SAW is λ, and a depth of the grooves is G, “0.01λ≦G” is satisfied.

A frequency modulator includes a digitally-controlled oscillator (DCO) arranged for producing a frequency deviation in response to a modulation tuning word and a phase-locked loop (PLL) tuning word. In addition, another frequency modulator includes a DCO and a DCO interface circuit. The DCO is arranged for producing a frequency deviation in response to an integer tuning word and a fractional tuning word. The DCO interface circuit is arranged for generating the integer tuning word and the fractional tuning word to the DCO, wherein the fractional tuning word is obtained through asynchronous sampling of a fixed-point tuning word.

Systems and methods for operating with oscillators configured to produce an oscillating signal having an arbitrary frequency are described. The frequency of the oscillating signal may be shifted to remove its arbitrary nature by application of multiple tuning signals or values to the oscillator. Alternatively, the arbitrary frequency may be accommodated by adjusting operation one or more components of a circuit receiving the oscillating signal.

A charge pump regulator circuit includes a voltage controlled oscillator and a plurality of charge pumps. The voltage controlled oscillator has a plurality of inverter stages connected in series in a ring. A plurality of oscillating signals is generated from outputs of the inverter stages. Each oscillating signal has a frequency or amplitude or both that are variable dependent on a variable drive voltage. Each oscillating signal is phase shifted from a preceding oscillating signal. Each charge pump is connected to a corresponding one of the inverter stages to receive the oscillating signal produced by that inverter stage. Each charge pump outputs a voltage and current. The output of each charge pump is phase shifted from the outputs of other charge pumps. A combination of the currents thus produced is provided at about a voltage level to the load.

Disclosed is an apparatus and method for generating energy through oscillatory motion requiring little input. Oscillatory motion is generated using a substantially circular trough containing a liquid, inflatable bags positioned below the trough and a movable weight. The trough is pivotally connected to a central point about which it oscillates. Sustained oscillatory motion is encouraged by inflating and deflating the bags in coordination with the movable weight within the trough and a biased member upon which the bags reside. The oscillatory motion may be captured and transferred to rotary motion which may be used to drive a generator.

An electrical circuit includes: at least one inductor, at least one varactor, and at least two transistors, all of which electrically arranged to form a voltage controlled oscillator (VCO) having an oscillation frequency; wherein the at least two transistors includes a first transistor and a second transistor; wherein the first transistor has a first bulk terminal and a first parasitic diode disposed between the first bulk terminal and the first transistor; wherein the second transistor has a second bulk terminal and a second parasitic diode disposed between the second bulk terminal and the second transistor; wherein application of a first control voltage to the first bulk terminal, application of a second control voltage to the second bulk terminal, or application of first and second control voltages to the first and second bulk terminals, respectively, is effective to change the oscillation frequency of the VCO.

A loop filter with an active discrete-level loop filter capacitor can be used in a VCO (such as for CDR). A loop filter capacitor function is simulated by sensing input loop filter current (such as with a current mirror and source follower in the input leg), and forcing back a loop filter (VCO) control voltage. Loop filter voltage control is provided using a VDAC with a discrete-level VDAC feedback voltage, incremented/decremented based on the sensed loop filter current. In one embodiment, the VDAC voltage is provided as the non-inverting input to an amplifier, with the inverting input providing the control voltage, forced to the VDAC feedback voltage. The VDAC feedback voltage can be provided by increment/decrement comparators based on a voltage deviation on a C2 capacitor (from a reference voltage) that receives the sensed loop filter current (effectively multiplying the C2 capacitance to provide a simulated loop filter capacitance).

Various embodiments mitigate the risk of frequency-lock in systems having multiple resonators by dynamically changing the frequency at which at least one of the resonators is driven. More particularly, the drive frequency of at least one of the resonators is changed often enough that the multiple resonators do not have time to achieve frequency lock. Changes in the oscillation of the resonators may be analyzed to determine, for example, acceleration of such systems. Some embodiments implement self-test by assessing expected performance of a system with toggling drive frequencies. More particularly, some embodiments implement self-test by artificially inducing displacement of a movable member of a system.

195?

Jozsef Csicsvari
Jan 1, 1999; 19:274-287
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