Relaxation oscillator

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

Electric remote control transmitter

Abstract: An electronic remote control transmitter employs a two transistor cascade oscillator having positive and negative feedback loops. The oscillator voltage is supplied through a switch assembly containing a plurality of momentary contact switches to a pair of voltage dividers supplying signal voltages in predetermined ratios to a two branch circuit in the negative feedback loop. One branch contains an inductor and the second branch a capacitor. Closure of any switch completes the DC circuits for the transistors. Signal voltage is supplied to the branches to produce a minimum amplitude, zero phase shift condition which establishes oscillation at that predetermined frequency. The output of the oscillator is amplified by a third transistor and supplied to an ultrasonic transducer for generating acoustical control signals.

1-V low-noise 200 MHz relaxation oscillator

Abstract: This paper presents a high-frequency current-controlled relaxation oscillator designed for ultra-low voltage supply (0.9 V). The choosen relaxation oscillator topology provides both high frequency and low noise characteristic. Simulated results are verified by measurements on a full-custom integrated circuit. The tuning range extends from 1 to 180 MHz with supply current limited to 1.1 mA. At a 200 kHz off set from the oscillator frequency, the measured phase noise is-89 dBc/Hz.

Lumped, inductorless oscillators: how far can they go?

Abstract: The fundamental question of how much we can ultimately reduce the phase noise of a lumped, inductorless oscillator through careful design is addressed and it is shown that the fluctuation dissipation theorem of thermodynamics imposes a 1,ower limit on the phase noise. An analytical formulation of this limit is presented and it is shown that the phase noise of ring oscillators with long-channel MOS devices is closer to this limit compared to that of the relaxation oscillators or ring oscillators with short channel MOS devices.

Low-power acoustic injector drive circuit with enhanced turn-on

Abstract: An acoustic fuel injector system comprises a DC-to-DC converter (14) for supplying a regulated voltage to a frequency controlled oscillator (16) which drives the injector valve (18) or valves. The converter comprises a flyback oscillator (28) including a switching transistor (32) and a transformer (34, 36) for applying rectified current pulses of variable amplitude and occurrence rate to an output capacitor (42). A variable impedance device (50) in the input circuit to the flyback oscillator is controlled by a feedback signal (68) from the output circuit (30) to vary the cycle rate of the flyback oscillator to maintain output voltage at a desired value. The feedback signal is coupled to the oscillator control circuit input to effect a variable regulated output voltage which is relatively high upon injector turn-on but decays to a lower operating level thereafter.

A low-power referenceless clock and data recovery circuit with clock-edge modulation for biomedical sensor applications

Abstract: This paper proposes a low-power referenceless clock and data recovery (CDR) circuit for biomedical devices or sensor applications. Its power consumption is reduced by adopting clock-edge modulation technique and using a voltage-controlled oscillator (VCO) based on a relaxation oscillator. Clock-edge modulation eliminates the need for an external reference clock without introducing the possibility of harmonic locking. Our CDR supports input data-rates between 200kbps and 10Mbps at 0.7V, and operate up to 24 MHz at 1.0V. The circuit is designed in a 0.18μm CMOS technology and consumes 8μW at an input data-rate of 10Mbps.