Relaxation oscillator

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

A magnetic feedback modulator for improved FM carrier recording

Abstract: Magnetic multivibrators are often used as voltage-controlled oscillators in FM carrier recording systems. These oscillators generally consist of two switching transistors connected to a center tapped coil on a square loop magnetic core. The transistors operate alternately in saturation, driving the core between its positive and negative saturation limits. Frequency then depends upon saturation flux and applied voltage. In the Magnetic Feedback Modulator, stability and linearity improvement of an order of magnitude is possible with a new method of applying negative feedback to a square-loop core magnetic multivibrator. In addition, circuit complexity is reduced considerably over previous methods using conventional frequency detectors to derive feedback voltage. Based on Faraday's Law, a voltage which is a function of frequency and flux change is derived from the magnetic circuit. This voltage is then used as negative feedback to the dc differential amplifier to drive the magnetic multivibrator. Since the magnetic circuit is included in the negative feedback loop, frequency errors occurring in the modulator cause corresponding changes in the magnetic feedback voltage. The errors are then reduced in magnitude by the negative feedback.

Simple Capacitance-to-Time Converter

Abstract: A method for implementing of a capacitive sensor interfacing circuit is proposed in this paper The time period generated from a simple relaxation oscillator is utilized to determine the time period obtained from the capacitive sensor The output parameter of the proposed converter is in the form of the time period The capacitance of the sensor can then be calculated using ratio metric operation The proposed converter can linearly convert the capacitance from the sensor to the time period The purpose of the proposed converter plays an attention in terms of simple configuration and low cost Performance of the proposed scheme is demonstrated by experimentally implementation The resulting confirmed that the performance of the proposed converter is in good agreement with the expected value

19.5 A 90µW 12MHz Relaxation Oscillator with a -162dB FOM

Abstract: University of Twente, Enschede, NetherlandsBoth ring oscillators and relaxation oscillators are subsets of RCoscillators featuring large tuning ranges and small areas Figure1951 shows a typical relaxation oscillator with a capacitor andtwo switched current sources Such relaxation oscillators havetwo advantages with respect to ring oscillators: 1) they have aconstant frequency tuning gain; and 2) their phase can be readout continuously due to their triangular (or sawtooth) waveformA major disadvantage of practical relaxation oscillators is theirpoor phase-noise compared to ring oscillators [1,2,4]The 1/

Relaxation oscillator and method

Abstract: A relaxation oscillator and a method of controlling the relaxation oscillator are disclosed. The relaxation oscillator includes a reference voltage generating circuit configured to generate a reference voltage based on a transistor-based resistor, a variable voltage generating circuit configured to generate a variable voltage based on the reference voltage and a control switch, a threshold voltage generating circuit configured to generate a threshold voltage using a switched-capacitor resistor circuit, and a switch control circuit configured to output a control signal to control the control switch based on the variable voltage and the threshold voltage.