Topic
Relaxation oscillator
About: Relaxation oscillator is a research topic. Over the lifetime, 1952 publications have been published within this topic receiving 22326 citations.
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01 Dec 1982
TL;DR: In this article, the frequency and damping time of relaxation oscillations allowing for both gain and total spontaneous emission rate to have arbitrary dependences on carrier concentration were investigated. And the exchange of power between dominant longitudinal modes, which occurs as a result of the peak gain shift with oscillating carrier concentration, was shown to occur on a time scale controlled by the damping times.
Abstract: Multimode rate equations have been used to investigate the response to a step current pulse of a semiconductor laser with built-in lateral waveguide. General expressions are given for the frequency and damping time of relaxation oscillations allowing for both gain and total spontaneous emission rate to have arbitrary dependences on carrier concentration. The exchange of power between dominant longitudinal modes, which occurs as a result of the peak gain shift with oscillating carrier concentration, is shown to occur on a time scale controlled by the damping time. The power exchange and the eventual domination by one or other mode are extremely sensitive to one key parameter – the wavelength displacement between peak gain and the adjacent Fabry-Perot mode.
24 citations
Patent•
03 Mar 1994
TL;DR: In this paper, a R-C relaxation oscillator having two comparators and a silicon controlled rectifier dissipates very low average power without resulting in frequency instabilities due to circuit propagation delays.
Abstract: An R-C relaxation oscillator having two comparators and a silicon controlled rectifier dissipates very low average power without resulting in frequency instabilities due to circuit propagation delays. A timing capacitor CT is charged through a timing resistor RT. The first comparator compares the voltage across the timing capacitor with an upper threshold voltage VTH. When the voltage across the timing capacitor crosses the upper threshold voltage, the comparator turns on the silicon controlled rectifier, which causes the capacitor to discharge the voltage that it has stored. The second comparator turns off the silicon controlled rectifier when the voltage across the timing capacitor falls below a lower threshold voltage VTL. The silicon controlled rectifier also provides boosted comparator bias current during the discharge phase, enabling the second comparator to respond quickly to the lower threshold voltage crossing and allowing fast capacitor discharge (therefore narrow clock pulses) and increasing frequency stability.
24 citations
Patent•
12 Apr 1937
TL;DR: In this paper, a relaxation oscillator of the blocking type is described. But this is not a generator of the kind known as relaxation oscillators of the block type, which is a kind of electric oscillation generators.
Abstract: This invention relates to electric oscillation generators and more particularly but not exclusively to generators of the kind known as relaxation oscillators. The invention is also more ' particularly concerned with relaxation oscillators of the blocking type. A blocking oscillator usually...
24 citations
Patent•
10 Oct 2003
TL;DR: In this article, a system and method for designing an integrated relaxation oscillator that exhibits reduced change in the frequency of oscillation caused by process variation is presented. But, the system is not suitable for the use of the Central Limit Theorem (CLT) for statistically uncorrelated events.
Abstract: A system and method for designing an integrated relaxation oscillator that exhibits reduced change in the frequency of oscillation caused by process variation. Improved sensitivity to component variation due to process shift is achieved through using more than one structure type when implementing the resistors affecting the RC time constant and threshold (trip point) voltages of the oscillator. Structure types are related to the fabrication process and for a CMOS process include, but are not limited to n-diffusion, p-diffusion, n-well, p-well, pinched n-well, pinched p-well, poly-silicon and metal. Each structure type exhibits statistically independent process variations, allowing for application of Lyapunov's extension of the Central Limit Theorem for statistically uncorrelated events to desensitize the effect from different possible causes. Thus, improvement in the performance of the oscillator may be achieved with a reduced trim requirement and without using external precision resistors.
24 citations
01 Jul 1955
TL;DR: In this article, a circuit was developed with which microwave oscillators may be phase-locked to weak but stable reference signals, and the power spectrum of the stabilized microwave source was calculated.
Abstract: A circuit has been developed with which microwave oscillators may be phase-locked to weak but stable reference signals. The circuit was operated with S-band oscillators (707B klystron; 2C37 triode oscillator) and a 2K50 K-band klystron. It is possible to lock a microwave oscillator directly or through a cascade of such circuits to a quartz-stabilized oscillator. The statistical theory of random noise is used to obtain an analysis of the stabilizing effect of the circuit, and the power spectrum of the stabilized microwave source is calculated. The scheme can also be applied in divider operation. Modifications are discussed. A modified circuit that uses carrier-suppressed modulation of the reference signal has also been realized. In another circuit, the oscillator frequency is converted by means of a stable reference, and compared with a second reference that can be of low frequency and tunable. These latter circuits allow elimination of the excess noise introduced by crystal diodes. In the original straight dc circuit this noise cannot be eliminated, but calculation shows that its influence on the output power spectrum is very small.
24 citations