Showing papers on "Relaxation oscillator published in 2017"
TL;DR: In this paper, a grounded memristor emulator circuit operating at high frequency was proposed, where two DC voltage sources are used for controlling the zero crossing of the frequency-dependent pinched hysteresis loop over a broad range of amplitude A m of the input signal.
Abstract: A grounded memristor emulator circuit operating from 16 Hz to 860 kHz is proposed. The emulator circuit is built around a plus-type second generation current conveyor, a four quadrant analog multiplier, a capacitor and a resistor. Two DC voltage sources are used for controlling the zero crossing of the frequency-dependent pinched hysteresis loop over a broad range of amplitude A m of the input signal, and principally when the memristor emulator circuit is operating at high-frequency. It describes in detail the derivation of the behavioral model of the proposed emulator circuit, including parasitic elements and showing that the charge-controlled memductance is a first-order function. Furthermore, a design guide to choose the numerical value of each discrete element in function of the operating frequency and A m is also given. The emulator circuit is built with off-the-shelf devices, and numerical results obtained by means of the behavioral model are compared with HSPICE simulations and experimental tests, showing good agreement among all them in a wide range of frequencies. This is against with some memristor emulator circuit available in the literature which present a good behavior at low-frequency and however, the zero crossing of the pinched hysteresis loop is deviated when the operating frequency increases. It is worth to stress that for the best knowledge of the authors, this is the first memristor emulator circuit that is operating to high-frequency. Moreover, the proposed emulator circuit can be configured as decremental or incremental memristor in order to be used in future applications such as cellular neural networks, modulators, sensors, chaotic systems, relaxation oscillators, nonvolatile memory devices and programmable analog circuits.
103 citations
TL;DR: In this article, a ferroelectric field effect transistor (FEFET)-based realization of non-linear, relaxation oscillators and their coupled networks is proposed to control oscillations, utilizing a unique physics of FEFETs: the dynamic voltage controllability of the location and width of the hysteresis loop.
Abstract: We propose ferroelectric field-effect transistor (FEFET)-based realization of non-linear, relaxation oscillators and their coupled networks. To control oscillations, we utilize a unique physics of FEFETs: the dynamic voltage controllabilityof the location and the width of the hysteresis loop. Such ferroelectric-basedcomplex, dynamical systems can lead to efficient physical platforms for alternative and neuromorphic computing paradigms.
49 citations
TL;DR: The coupling dynamics of capacitively coupled Nb/Nb2O5 relaxation oscillators are shown to exhibit rich collective behaviour depending on the negative differential resistance response of the individual devices, the operating voltage and the coupling capacitance.
Abstract: The coupling dynamics of capacitively coupled Nb/Nb2O5 relaxation oscillators are shown to exhibit rich collective behaviour depending on the negative differential resistance response of the individual devices, the operating voltage and the coupling capacitance. These coupled oscillators are shown to exhibit stable frequency and phase locking states at source voltages as low as 2.2 V, with frequency control in the range from 0.85 to 16.2 MHz and frequency tunability of ~8 MHz V–1. The experimental realisation of such compact, scalable and low power coupled-oscillator systems is of particular significance for the development and implementation of large oscillator networks in non-Boolean computing architectures.
35 citations
TL;DR: A novel readout circuit for interfacing single element resistive sensors is presented, based on a new relaxation oscillator (RO), which provides a digital output proportional to the resistance of the sensor.
Abstract: A novel readout circuit for interfacing single element resistive sensors is presented in this paper. The proposed scheme is based on a new relaxation oscillator (RO). The RO, along with a timer counter provides a digital output proportional to the resistance of the sensor. The output characteristic of most of the existing readout circuits for resistive sensors suffers from gain, offset, and nonlinearity errors. The sources of errors include various nonideal circuit parameters and their drift. The output of the proposed readout circuit has a special feature that it is not a function of the circuit parameters such as: 1) offset voltages of the opamps and comparators; 2) bias currents of the opamps and comparators; 3) gain of various units employed; 4) ON-resistance of the switches; 5) value or mismatch in the magnitudes of the reference voltages employed; 6) delay of the switches and comparator; 7) leakage current of the switch; and 8) slew rate of the opamp. Such a scheme will be useful for high accuracy measurements, even when the parameters 1)–8) may vary or drift, due to variation in the measurement environment. A prototype of the proposed readout scheme has been developed in the laboratory and the performance has been evaluated under various conditions. The output was found to be linear with a worst-case nonlinearity of 0.05%. Test results from a prototype developed show that the proposed scheme possesses all the features, described above, as expected.
33 citations
TL;DR: The proposed oscillator employs an integrated error feedback and composite resistors to minimize its sensitivity to temperature variations and demonstrates a frequency variation less than ±0.13%, leading to an average frequency drift of 21.8 ppm/°C.
Abstract: A 51.3-MHz 18- $\mu\text{W}$ 21.8-ppm/°C relaxation oscillator is presented in 90-nm CMOS. The proposed oscillator employs an integrated error feedback and composite resistors to minimize its sensitivity to temperature variations. For a temperature range from −20 °C to 100 °C, the fabricated circuit demonstrates a frequency variation less than ±0.13%, leading to an average frequency drift of 21.8 ppm/°C. As the supply voltage changes from 0.8 to 1.2 V, the frequency variation is ±0.53%. The measured rms jitter and phase noise at 1-MHz offset are 89.27 ps and −83.29 dBc/Hz, respectively.
32 citations
TL;DR: In this article, an actuation method is proposed to set into mechanical resonance a microstructure without the need of any active electronics, with small power consumption and with the possibility to selectively excite specific flexural modes by tuning the value of the DC electrical bias in a range of few hundreds of millivolts.
Abstract: Relaxation oscillators consist of periodic variations of a physical quantity triggered by a static excitation. They are a typical consequence of nonlinear dynamics and can be observed in a variety of systems. VO2 is a correlated oxide with a solid-state phase transition above room temperature, where both electrical resistance and lattice parameters undergo a drastic change in a narrow temperature range. This strong nonlinear response allows to realize spontaneous electrical oscillations in the megahertz range under a DC voltage bias. These electrical oscillations are employed to set into mechanical resonance a microstructure without the need of any active electronics, with small power consumption and with the possibility to selectively excite specific flexural modes by tuning the value of the DC electrical bias in a range of few hundreds of millivolts. This actuation method is robust and flexible and can be implemented in a variety of autonomous DC-powered devices.
31 citations
01 Feb 2017
TL;DR: RC Relaxation Oscillators are attractive for integrated clock sources compared to LC and ring oscillators (RO), as LC oscillators pose integration challenges and RO designs have limited voltage and temperature (V-T) stability.
Abstract: RC Relaxation Oscillators (RxO) are attractive for integrated clock sources compared to LC and ring oscillators (RO), as LC oscillators pose integration challenges and RO designs have limited voltage and temperature (V-T) stability. RxOs generate a clock whose time period (T P ) depends only on the timing resistor (R) and capacitor (C). Ideally, T P is independent of V-T; however, most RxOs use a reference voltage (V REF ) against which the voltage of C (Vc) is compared. Generating a V-T-independent V REF is non-trivial and causes variations in RxO frequency. A common approach is the use of VDD-independent current sources or band-gap or device-V t -based V REF [1]. The former are generally high-power options [2] while the latter is subject to process and V-T variations. A correct-by-design approach was adopted in [3] demonstrating VDD-independent operation by cancelling variations through differential sampling of VDD. Further, the power overhead of a supply-independent V REF is overcome by exploiting differential-integrator virtual ground. However, 4V2/R power in the RC tank and high-power VCO increase the energy/cycle.
30 citations
07 Feb 2017
TL;DR: In this article, a swing-boosted differential scheme was proposed to reduce the effect of comparator noise by boosting the signal slope at the comparator input, demonstrating an FOM of over 160dBc/Hz.
Abstract: With the emergence of wearable and implantable technologies, there has been growing demand on development of key enabling circuits for ultra-low-power sensor interface SoCs. As a reference-frequency generation block for clock management of the overall system, the relaxation oscillator has been widely adopted since it can provide a controllable and well-defined untrimmed frequency with low-cost circuits. In the past decade, the major goal in the design of the relaxation oscillators has been the improvement of phase-noise figure-of-merit (FOM) closer to the fundamental limit of 169dBc/Hz [1]. There have been feedback approaches to internally generate reference voltages for comparison, hence compensating the comparator circuit delay [2–4]. Since the delay compensation relies on the feedback operation, power consumption by analog circuits to meet the required bandwidth of the feedback loop eventually limits FOM. Recently, a swing-boosted differential scheme was proposed to reduce the effect of comparator noise by boosting the signal slope at the comparator input, demonstrating an FOM of over 160dBc/Hz [5]. However, the boosted voltage swing can increase stress on the input transistors of the comparator. In addition, a high-speed comparator is also needed to reduce the effect of the circuit delay on the output frequency. While most of previous works achieved good FOMs with MHz oscillators, implementation of low-frequency relaxation oscillators presents additional challenges since it requires excessive area for RC and power consumption by analog circuits with leakage not scaled down along with the output frequency.
27 citations
TL;DR: In this paper, the temperature dependence of current-controlled negative differential resistance (CC-NDR) in Pt/NbOx/TiN devices and its effect on the dynamics of associated Pearson-Anson relaxation oscillators was investigated.
Abstract: This study investigates the temperature dependence of current-controlled negative differential resistance (CC-NDR) in Pt/NbOx/TiN devices and its effect on the dynamics of associated Pearson-Anson relaxation oscillators. The voltage range over which CC-NDR is observed decreases with increasing temperature such that no NDR is observed for temperatures above ∼380 K. Up to this temperature, relaxation oscillators exhibit voltage and temperature dependent oscillation frequencies in the range of 1 to 13 MHz. Significantly, the sensitivity of the frequency to temperature changes was found to be voltage-dependent, ranging from 39.6 kHz/K at a source voltage of 2 V to 110 kHz/K at a source voltage of 3 V, in the temperature range of 296–328 K. Such a behaviour provides insights into temperature tolerance and tuning variability for environmentally sensitive neuromorphic computing.
21 citations
01 Sep 2017
TL;DR: A relaxation oscillator that utilizes a supply-stabilized pico-powered voltage and current reference (VCRG) to charge and reset a chopped pair of MIM capacitors at sub-nW power levels is presented.
Abstract: This paper presents a relaxation oscillator that utilizes a supply-stabilized pico-powered voltage and current reference (VCRG) to charge and reset a chopped pair of MIM capacitors at sub-nW power levels. Specifically, a temperature- and line-stabilized reference voltage is generated via a 4-transistor (4T) self-regulated structure, the output of which is used to bias a temperature-compensated gate-leakage transistor to generate a stabilized current reference. The reference current is then used to charge a swapping pair of MIM capacitors to compare to the voltage generated by the same VCRG in a relaxation topology. The design is fabricated in 65 nm CMOS, and 14 measured samples yield a reference voltage of 147.1 mV achieving a temperature coefficient of 364 ppm/°C and a line regulation of 0.21%/V, and a reference current of 10.2 pA achieving a temperature coefficient of 1077.3 ppm/°C and a line regulation of 1.79%/V (all numbers averaged across all samples). The proposed VCRG-based relaxation oscillator achieves an average temperature coefficient of 999.9 ppm/°C from −40 to 120° C and a line regulation of 1.6%/V from 0.6 to 1.1 V, all at a system power consumption of 124.2 pW at 20° C.
19 citations
TL;DR: In this article, a novel model of general purpose operational amplifiers is made to approximate, at best, the equivalent circuit for real model at high-frequency, and it appears that certain oscillators, usually studied under ideal considerations or using many existing real models of operational Amplifiers, have hidden subtle and attractive chaotic dynamics that have previously been unknown.
Abstract: A novel model of general purpose operational amplifiers is made to approximate, at best, the equivalent circuit for real model at high-frequency. With this new model, it appears that certain oscillators, usually studied under ideal considerations or using many existing real models of operational amplifiers, have hidden subtle and attractive chaotic dynamics that have previously been unknown. These can now be revealed. With the new considerations, a “two-component” circuit, consisting simply of a capacitor in parallel with a nonmodified (and usually presented as a linear, negative) resistance, tends to exhibit chaotic signals. P-Spice and laboratory experimental results are in good agreement with the theoretical predictions.
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17 Apr 2017TL;DR: In this article, a phase comparator that performs phase comparison between an input signal based on an oscillation signal and a reference signal, a processor that performs a signal process, and an OSS generator circuit that generates the OSS signal having an oscillated frequency which is set on the basis of frequency control data from the processor.
Abstract: A circuit device includes a phase comparator that performs phase comparison between an input signal based on an oscillation signal and a reference signal, a processor that performs a signal process, and an oscillation signal generation circuit that generates the oscillation signal having an oscillation frequency which is set on the basis of frequency control data from the processor. The circuit device also includes at least one of a first register that stores phase comparison result data, a second register in which one of offset adjustment data for GPS and offset adjustment data for UTC is set, and a third register in which offset adjustment data for adjusting a phase difference is set.
01 May 2017
TL;DR: Simulated results demonstrated that the proposed ROSC generates 32.5-kHz clock frequency and achieves ultra-low power dissipation of 271 nW and Monte Carlo statistical simulations showed that the mean, standard deviation, and the coefficient of variation are 32.3 kHz, 0.6 kHz, and 1.9%, respectively.
Abstract: In this paper, we propose a fully integrated and area-efficient resistor-less relaxation oscillator (ROSC) for ultra-low power real-time clock (RTC) applications. The proposed ROSC is based on a conventional ROSC and modified to be area-efficient circuit configuration, without using resistors. The proposed ROSC consists of a bias current source, proportional to absolute temperature (PTAT) voltage source, current mode ROSC, shunt regulator, and output logic circuit. The PTAT voltage source and shut regulator are used to compensate for the temperature characteristics of the ROSC. By implementing our proposed ROSC in a 65-nm CMOS process, the area was 0.022 mm2. Simulated results demonstrated that our proposed ROSC generates 32.5-kHz clock frequency and achieves ultra-low power dissipation of 271 nW. The temperature and voltage dependences of the oscillation frequency were 138ppm/°C and 13.9ppm/mV, respectively. Monte Carlo statistical simulations showed that the mean, standard deviation, and the coefficient of variation are 32.3 kHz, 0.6 kHz, and 1.9%, respectively.
04 Jun 2017
TL;DR: In this paper, a 140MHz relaxation oscillator with robust-against-process-variation temperature compensation scheme is presented for the first time, which achieves 28 ppm/°C frequency stability over the automotive temperature range from −40 to 175°C.
Abstract: The need for high-frequency, low-power, wide temperature range, precision on-chip reference clock generation makes relaxation oscillator topology an attractive solution for various automotive applications. This paper presents for the first time a 140MHz relaxation oscillator with robust-against-process-variation temperature compensation scheme. The high-frequency relaxation oscillator achieves 28 ppm/°C frequency stability over the automotive temperature range from −40 to 175°C. The circuit is fabricated in 40nm CMOS technology, occupies 0.009 mm2 and consumes 294µW from 1.2V supply.
TL;DR: In this article, a 16-bit frequency detector with a digital output has been proposed to detect the frequency difference between two oscillators based on healthy blood and Leukaemic blood.
Abstract: This paper proposes a technique to detect Leukaemia (blood cancer) based on the frequency modulation of a relaxation oscillator by changes in the dielectric constant of blood cells. A novel 16-bit frequency detector with a digital output has been proposed to detect the frequency difference between two oscillators based on healthy blood and Leukaemic blood. A circuit has been designed, to operate on a 1.2 V supply, post layout simulations shows 0.35 mA current consumption. The chip Area including pads ~0.6 mm × 0.45 mm.
TL;DR: A new inverter-based architecture that implements an asynchronous delta–sigma modulator that features an input transconductor that promotes a differential and high input impedance that makes it easier to interface with sensors and other front ends is presented.
Abstract: This paper presents a new inverter-based architecture that implements an asynchronous delta–sigma modulator. Different from the classical architecture, it features an input transconductor that promotes a differential and high input impedance that makes it easier to interface with sensors and other front ends. Furthermore, an inverter-based relaxation oscillator accomplishes the required hysteresis through a charge redistribution process, which exhibits lower time delay than hysteretic comparators, besides saving power from quiescent biasing. The circuit has been implemented in 130-nm CMOS digital process using halo-implanted transistors. In addition, transistors are biased in weak inversion and are implemented using distributed layout to reduce power consumption besides mitigating halo-implants undesired effects. Supplied with 0.25 V, the proposed architecture consumes 20 nW with just −55 dB of third harmonic distortion, making it suitable for wearable biomedical applications where energy consumption, low bandwidth, and moderate resolution are required.
TL;DR: In this paper, a fully-integrated 12 kHz relaxation oscillator for energy harvesting application is presented, where a conventional comparator has been replaced by a pseudo-inverter chain to avoid comparator offset effect.
Abstract: A fully-integrated 12 kHz relaxation oscillator for energy harvesting application is presented. The oscillator has no comparator and no reference voltage. A conventional comparator has been replaced by a pseudo-inverter chain to avoid comparator offset effect. Moreover, inverter threshold variation has no impact on the frequency. The circuit has been designed with 0.18 μm standard CMOS process. The oscillator operates in subthreshold region and consumes an ultra-low power of 120 nW. A temperature coefficient of 31 ppm/°C has been achieved over -40 to 90°C.
23 Mar 2017
TL;DR: In this article, the authors proposed an innovative low voltage, 70 MHz frequency oscillator circuit, designed for sub micrometer technologies, based on constant threshold inverters, featuring low supply voltage influence on the output frequency.
Abstract: The present work proposes an innovative low voltage, 70 MHz frequency oscillator circuit, designed for sub micrometer technologies, based on constant threshold inverters. The circuit comes as a direct replacement for the current starved ring oscillator topology, featuring low supply voltage influence on the output frequency. The designed supply voltage range is between 1.6V and 2V.
TL;DR: In this article, a modified relaxation oscillator circuit that can simultaneously determine the capacitance and drive the rotator is presented, which can achieve arbitrary polarization rotation from nematic liquid crystals.
Abstract: We report a capacitance tracking method for achieving arbitrary polarization rotation from nematic liquid crystals. By locking to the unique capacitance associated with the molecular orientation, any polarization rotation can be achieved with improved accuracy over a wide temperature range. A modified relaxation oscillator circuit that can simultaneously determine the capacitance and drive the rotator is presented.
01 May 2017
TL;DR: A novel relaxation oscillator (ROSC) with a merged window comparator, an optimized parallel/series composite resistor and a reference generator on the basis of threshold monitoring circuit is presented, which achieves offset cancellation by adopting the mergedwindow comparator.
Abstract: A novel relaxation oscillator (ROSC) with a merged window comparator, an optimized parallel/series composite resistor and a reference generator on the basis of threshold monitoring circuit is presented The ROSC achieves offset cancellation by adopting the merged window comparator The optimized composite resistor is employed to reduce the output frequency temperature coefficient (TC) even in the presence of process variation The oscillator is realized in 65nm CMOS process At a supply voltage of 12V, the current consumption is 747μΑ The simulated frequency TC is 1469ppm/°C over the temperature range of −20∼120°C and the line sensitivity is 0188%/V over the supply voltage range of 12∼23V
01 Mar 2017
TL;DR: A highly linear voltage to time converter that can be used as a brick in the architecture of time-domain analog-to-digital converter based on injection locked oscillators as phase shifter is presented.
Abstract: In this paper, a highly linear voltage to time converter is presented. It can be used as a brick in the architecture of time-domain analog-to-digital converter. It is based on injection locked oscillators as phase shifter. The injection locked oscillator is implemented using a relaxation oscillator that has been chosen for its high linearity compared to other conventional architectures. The analog-to-time domain converter is designed using 0.18μm Partially Depleted Silicon On Insulator technology. It converts the analog information into time-domain information as a phase shift and it has a linearity range of 180°.
01 Oct 2017
TL;DR: In this paper, a compensation technique has been proposed to reduce the oscillation frequency error observed in the output waveform of an op-amp-based relaxation oscillator for capacitance and resistance measurements.
Abstract: Relaxation oscillator based capacitance and resistance measurements are investigated with a compensation technique. Output oscillation frequency of op-amp based relaxation oscillator changes over a range of capacitance variation. The range of capacitance variation considered for measurement is between 57.1 and 206.4 pF. The output oscillation frequency deviates from the theoretical value due to non-idealities of opamp. A compensation technique has been proposed to reduce the oscillation frequency error observed in output waveform. The performance of the op-amp is evaluated again post compensation. The experimental results are compared with an integrator based relaxation oscillator and comparator configuration. Further, the concept of utilizing the compensated relaxation oscillator for resistance measurement has been experimented. The compensated relaxation oscillator provide the improved performance in oscillation frequency of the waveform. Thus, the compensated relaxation oscillator could be employed for both resistive and capacitive sensing for two different measurements such as temperature and moisture measurements.
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26 Sep 2017
TL;DR: In this article, a high-precision and self-adapting relaxation oscillator is proposed to offset time delay produced by a charge-discharge control circuit arranged in an oscillating circuit according to a capacitor precharging principle.
Abstract: The invention provides a high-precision and self-adapting relaxation oscillator. The high-precision and self-adapting relaxation oscillator offsets time delay produced by a charge-discharge control circuit arranged in an oscillating circuit according to a capacitor precharging principle, and comprises the oscillating circuit, a first capacitor precharging circuit and a second capacitor precharging circuit, wherein the capacitor precharging circuits are used for precharging a charge-discharge capacitor of the oscillator, the oscillating circuit performs charging and discharging on the basis of precharging level of the capacitor precharging circuits, error time delay produced by the capacitor during two times of charging is offset, so that the oscillator works at preset frequency, and frequency-control current linearity is remarkably improved. The time delay is not reduced by directly increasing speed of a comparator or an RS trigger, the time delay produced by the control circuit and influence of imbalance with external environment change are offset through two times of charging processes, the precision of the oscillator is obviously improved, and the oscillator has quite high temperature stability and power supply rejection, namely, adaptability.
28 Aug 2017
TL;DR: A model of the oscillator with inductive coupling of the gates operating at ultralow voltage is presented and experimentally verified and the circuit, which behaves as astable multivibrator, could work with a power supply as low as 50 mV using the starting block.
Abstract: In this work a model of the oscillator with inductive coupling of the gates operating at ultralow voltage is presented and experimentally verified. The topology needs a bias voltage at the gates, and we propose a circuit called starting block to generate this voltage from the supply. Theoretical behavior is compared with experimental results, showing good agreement. The circuit, which behaves as astable multivibrator, could work with a power supply as low as 50 mV using the starting block and deliver 560 gW from a supply of 100 mV. The oscillator is able to be used in the energy harvesting process from low voltage sources for autonomous systems like medical implants and sensor networks.
Patent•
06 Jan 2017
TL;DR: In this paper, a relaxation oscillator circuit is proposed to provide current from the current source based on the output clock signal, with a Schmitt trigger configured to be current starved by a first starved current of the plurality of starved currents.
Abstract: A relaxation oscillator circuit includes a current mirror configured to receive the input current from the and generate a plurality of starved currents, a Schmitt trigger configured to be current starved by a first starved current of the plurality of starved currents and a plurality of inverters configured to receive a Schmitt trigger output signal and generate an output clock signal, the inverters including a plurality of current starved inverters that are current starved by a second starved current of the plurality of starved currents, the plurality of current starved inverters receiving the Schmitt trigger output signal and generating a first inverter output signal, upon which an output clock signal is based. The relaxation includes a capacitor configured to charge or discharge in response to the output clock signal and a switching module configured to provide current from the current source based on the output clock signal.
01 Nov 2017
TL;DR: According to the extensive simulation results, the variation of the proposed RO's output frequency is reduced to ±0.18% with the working temperature ranged from −55° C to 125° C, outperforming the other state of art RO designs.
Abstract: In this paper, we present a novel on-chip relaxation oscillator (RO) with high temperature stability. By employing delay compensation circuit (DCC) in the delay loop, the transmission delay, which is highly sensitive to the temperature variation, is well-suppressed, leading to significantly elevated temperature stability of the RO's period. In addition, the proposed RO implementation features a low power consumption of 0.11μW at 25° C, using 65nm 1.2V standard CMOS process. Moreover, according to our extensive simulation results, the variation of our proposed RO's output frequency is reduced to ±0.18% with the working temperature ranged from −55° C to 125° C, outperforming the other state of art RO designs.
TL;DR: This letter presents a new pseudo-random pattern generator using a memristor and relaxation oscillator based on an operational amplifier, and from the simulation results, it is shown that the pulse width time is 7.6 μs, and the random pulse sequence is 2048 bits.
Abstract: This letter presents a new pseudo-random pattern generator using a memristor and relaxation oscillator based on an operational amplifier. The pulse width of the proposed generator is determined by the resistance storage property of the memristor, and the random pulse sequence depends on the RC time constant of the relaxation oscillator. From the simulation results, we show that the pulse width time is 7.6 μs, and the random pulse sequence is 2048 bits. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
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11 Jan 2017
TL;DR: In this article, a height-adjustable table lamp with adjustable adjustable adjustable variable resistor and a light resistor was presented, which can be used as a trigger tube of the adjustable table lamp.
Abstract: The invention discloses a height-adjustable table lamp. The adjustable table lamp comprises a thyristor VS, a lamp HL, a photo resistor R3, a bridge rectification circuit, a relaxation oscillator, a voltage divider and a photo resistor RG, wherein the lamp HL is connected with the bridge rectification circuit, the bridge rectification circuit is connected with a resistor R1 and the thyristor VS respectively, the thyristor VS is connected with the relaxation oscillator, the relaxation oscillator is connected with a diode VD5 and the voltage divider respectively, the voltage divider is connected with the light resistor RG, the bridge rectification circuit comprises a diode VD1, a diode VD2, a diode VD3 and a diode VD4, the thyristor VS and the bridge rectification circuit form a full-wave phase control circuit, an neon tube N is used as a trigger tube of the thyristor VS, and the relaxation oscillator comprise an adjustable variable resistor RP, a capacitor C and the neon tube N. The device is simple in structure, the circuit system is high in controllability and low in cost, and can be widely accepted by consumers.
TL;DR: In this article, the effects that limit the performance of practical implementations of RC relaxation oscillators are investigated, and the insights gained are used to suggest a topology for high-frequency quadrature relaxation oscillator with closer-to-optimal performance.
Abstract: In this paper, the effects that limit the performance of practical implementations of RC relaxation oscillators are investigated. The insights gained are used to suggest a topology for high-frequency quadrature relaxation oscillators with closer-to-optimal performance. The proposed oscillator uses a modified latch to improve the switching speed without increasing the power consumption. Moreover, the new topology avoids static current sources, maximizes the voltage swing and has an active coupling structure without static power consumption that reduces the circuit phase-noise. Experimental results show that the oscillator operates in relaxation mode at 2.4 GHz and achieves a FoM of $$\mathrm {-162\,dBc/Hz}$$-162dBc/Hz, which is, as far as the authors know, the best FoM for relaxation oscillators operating in the GHz range.
TL;DR: A modified relaxation oscillator circuit that can simultaneously determine the capacitance and drive the rotator is presented, and any polarization rotation can be achieved with improved accuracy over a wide temperature range.
Abstract: We report a capacitance tracking method for achieving arbitrary polarization rotation from nematic liquid crystals. By locking to the unique capacitance associated with the molecular orientation, any polarization rotation can be achieved with improved accuracy over a wide temperature range. A modified relaxation oscillator circuit that can simultaneously determine the capacitance and drive the rotator is presented.