Relaxation oscillator

About: Relaxation oscillator is a research topic. Over the lifetime, 1952 publications have been published within this topic receiving 22326 citations.

Synchronization of a forced relaxation oscillator

Abstract: The paper presents a method of synchronizing a relaxation oscillator to an external signal. The synchronization mechanism is linear and a detailed analysis is given. Very fast acquisition is shown to be possible. The oscillator synchronizes to the frequency of the forcing input or to a sub- or superharmonic. Possible applications include high-speed timing recovery systems where high acquisition speed is required

Pulse and square wave generator

Abstract: This invention relates to square wave generators and particularly to pulse and square wave generators utilizing a multivibrator circuit. A multivibrator is an oscillator comprising two thermionic tubes having their plates cross-connected by condensers to their grids. In other words, the plate...

Relaxation oscillator using spintronic device

Abstract: Disclosed herein is a relaxation oscillator using a spintronic device. The relaxation oscillator includes a power source unit, a spintronic device, and a capacitor. The power source unit applies power. The spintronic device is driven by the power applied by the power source unit, and has a variable voltage value depending on the intensity of a magnetic field. The capacitor is connected in parallel with the spintronic device, and is discharged when it assumes a minimum-voltage value in the threshold voltage range of the spintronic device and charged when it assumes a maximum voltage value in the threshold voltage range.

A low-power accelerometer IC with high sensitivity

Abstract: The objective of this project is to design a low-power, low-noise, highly-sensitive accelerometer ASIC interface using standard CMOS technology. The capacitive acceleration sensor is based on Micro-Electro-Mechanical Systems (MEMS) technology. For the targeted security applications, the bulk-micromachined accelerometer which has been developed by Temasek Laboratory@NTU, is employed as the sensing element to couple with the abovementioned ASIC readout circuit. The auto-zero time-multiplexed differential technique is able to tolerate a number of circuit non-idealities. These include operational amplifier (op-amp) offset, offset thermal drift and switch errors of switched-capacitor (SC) circuits. The unique single-ended circuit architecture avoids the stringent requirement for component matching and eliminates the common-mode problem in conventional fully differential interface circuitry. Ultimately, it improves S/N ratio and cancels the common-mode errors in the sensing system with low power consumption. For the implementation of the ASIC design to the intended accelerometer application, it involves several circuit building blocks. They are readout circuit, oscillator, differential-to-single-ended SC gain amplifier stage, passive RC filter and low-offset low-noise op-amp buffer. A novel Auto-Zero Time-multiplexed Capacitance-to-Voltage Converter (AZTMD-CVC) is proposed for the readout circuit in this project. The circuit architecture achieves differential output performance whilst using only single-ended CVC topology. This approach eliminates the use of bulky full Wheatstone bridge sensing element in the MEMS sensor as required in conventional fully differential sensor interface architecture, with additional benefit in reducing the fabrication cost of the MEMS sensor and readout circuit, as well as the power consumption. Besides, a low-power design strategy, pertaining to power versus noise in the readout circuit, is proposed. It permits the design to attain low noise without using excessive power consumption. This offers the optimal power-noise product in a form of figure-of-merit (FOM) on the AZTMD-CVC. Two new oscillator circuits have been presented in this work. Both the oscillator designs offer clock signals with good temperature and supply variation immunity. The first oscillator design is a compact low-power CMOS ring oscillator with temperature and supply compensation whereas the second oscillator design deals with the relaxation oscillator using the tracking current comparator. The second design is adopted in this AZTMD-CVC circuit together with the silicon implementation for prototype testing. The key feature of the second oscillator is that of the temperature compensation without resorting to any external resistor component. The tracking current comparator based oscillator provides a 172 kHz clock for the interface circuit. This clock signal displays a 0.17% variation within the supply range from ±1.6V to ±2V whereas the mean temperature compensated coefficient for 5 samples of this oscillator…

Excitation of a Langmuir wave by an ion sound wave and relaxation oscillation

Abstract: A detailed analysis of the plasma-maser effect is shown. Coupled equations for the Langmuir and ion sound waves are reduced to the Lotka-Volterra type. A relaxation oscillation around a steady state is analyzed. The finite-amplitude effect of the ion sound pump field on the excitation of the Langmuir wave is qualitatively discussed.