Relaxation oscillator

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

Control circuit for phase controlled oscillator - with pull-in range increased by positive and negative feedback with diode switching

Abstract: The range of this control loop circuit for a phase controlled oscillator is increased by employing a combination of positive and negative feedback to an amplifier which produces a sawtooth waveform output for tuning the oscillator until it locks to a predetermined frequency. This circuit maintains a constant feedback current and eliminates the need for critical or frequency dependent feed back. The output voltage of an amplifier (3) is fed back to its inverting and its non-inverting inputs (12,11) via a capacitor (5) in a positive sense (5,6) and a negative sense (5,7,8) respectively. The negative feedback via diodes (7,8) comes into effect when these diodes conduct at a predetermined threshold voltage.

Analysis of a kind of diode over-current oscillation mechanism

Abstract: Under certain conditions, semiconductor diodes will produce the phenomenon of current periodic change in DC circuit. We designed a experiment due to some certain silicon epitaxial planar diode, and the test results showed that when the current flowing the diode overruns rated value, current regular relaxation oscillation appears, and the oscillation period is in several seconds. As long as the voltage remains the same, this kind of relaxation oscillation can last a few minutes, even longer. This phenomenon is different from Gunn oscillation, because oscillation frequency of the latter is much more than that of the former. Studying this kind of phenomenon has potential application prospect in the area developing new-type oscillators, helps to look into working performance of semiconductor diode, and further overcomes the deficiency of manufacturing process.

Memristor-Based Relaxation Oscillator Circuits

Abstract: This chapter discusses the analysis and design of memristor-based oscillators which is considered one of the nonlinear analog block required for many applications such as chaotic memristor oscillators and artificial neuron network. The realizations of memristor-based oscillators have been discussed via replacing capacitors with memristors to construct relaxation reactance-less oscillators. The advantages of such oscillators are related to low frequency, nanoscale, and simple designs and can be used in neuromorphic systems. Different topologies of memristor-based relaxation oscillators have been discussed and either symmetric or asymmetric types with analytical formulas of oscillation frequency and condition for oscillations are derived. The analyses of these oscillators are introduced with their numerical simulations, and verified using PSPICE circuit simulations showing a great matching. Moreover, many fundamentals are also discussed such as the effect of boundary dynamics, series and parallel connections as well as power analysis in memristor-based circuits.

Control of Resonant Switched-Capacitor Converters

Abstract: A dynamic model for the nonlinear mixed-signal control loop of switch conductance regulation (SwCR) is proposed. The model allows to analyze the stability for this class of ReSC converters and, accordingly, to optimize the design of the control loop. An analytic stability criterion is derived based on a harmonic balance approach (also called describing function analysis) together with the dual locus method. The model is verified by measurements of the proposed resonant SC converter that operates up to a resonance frequency of 47 MHz. The presented modeling methodology can be applied to other areas, such as digital LDO, slope shaping, or digitally assisted analog.