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Relaxation oscillator

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


Papers
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Proceedings ArticleDOI
31 Oct 2005
TL;DR: An interface circuit for grounded capacitive sensors has been designed using a simple relaxation-oscillator topology and has been implemented in a 0.7mum CMOS process.
Abstract: An interface circuit for grounded capacitive sensors has been designed. The circuit is designed using a simple relaxation-oscillator topology and has been implemented in a 0.7-mum CMOS process. The output signal is a period-modulated square-wave signal, which can directly be processed with a microcontroller. The period time of the output signal is proportional to the measured capacitance. By using the "three-signal" autocalibration methodology, obvious disadvantages from simple relaxation oscillators, such as offset, long-term drift, etc., have been overcome. The paper shows even with a very simple circuit a rather good performance for the measurement of grounded capacitances can be achieved. An active-guard amplifier has been applied to reduce the influence of parasitic capacitances. For the active-guard amplifier, an opamp as well as an operational transconductance amplifier (OTA) have been used. Their performances, regarding to their high-frequency stability and accuracy for large capacitive loads at the working frequency, have been compared. For the measurement range of 100 pF up to 2 muF the nonlinearity is found to be better than 0.5% and the standard deviation less than 20 ppm for a measurement time of 100 ms

15 citations

Patent
07 Dec 1970
TL;DR: In this paper, a temperature stable integrated oscillator has a control loop including a flip-flop, a series resistor-capacitor timing circuit, reference voltage means and a comparator.
Abstract: A temperature stable integrated oscillator has a control loop including a flip-flop, a series resistor-capacitor timing circuit, reference voltage means and a comparator. The comparator compares the reference voltages to the voltage swing across the capacitor to actuate the flip-flop and thereby provide the oscillator output frequency. Temperature stability is provided by making both the voltage swing across the flip-flop and the reference voltage proportional to the difference between the power supply voltage and the base emitter drop of associated integrated transistors.

15 citations

Patent
27 Jul 1970
TL;DR: In this article, a system for sensing levels of electricallyconductive liquid by utilizing the liquid as a switch in cooperation with electrical probes is disclosed, where the destructive effects of liquid conduction on the probe are avoided by the use of pulse techniques.
Abstract: A system is disclosed for sensing levels of electricallyconductive liquid by utilizing the liquid as a switch in cooperation with electrical probes. The destructive effects of liquid conduction on the probe are avoided by the use of pulse techniques. A pulse generator operates when the liquid under observation attains a probe-contact level to complete an electrical circuit. The pulse generator is disclosed in the form of a relaxation oscillator which pulses a trigger circuit, the output of which is integrated to provide a control signal. A plural-probe system is also disclosed. The pulses provided from the pulse generator have an interval of not more than one fifth of the interval therebetween.

15 citations

Proceedings ArticleDOI
Bo Zhou1, Rui He1, Jian Qiao1, Jinghui Liu1, Woogeun Rhee1, Zhihua Wang1 
01 Nov 2010
TL;DR: In this article, the authors describe the architecture and circuit design of a low data rate FM-UWB transmitter with a Δ-Σ fractional-N PLL with a multi-phase relaxation oscillator to enable sub-carrier modulation with reduced quantization noise.
Abstract: This paper describes the architecture and circuit design of a low data rate FM-UWB transmitter. A Δ-Σ fractional-N PLL with a multi-phase relaxation oscillator is designed to enable sub-carrier modulation with reduced quantization noise. The triangular waveform output of the relaxation oscillator directly modulates an LC VCO to have the UWB-compliant spectrum. The center frequency of the LC VCO is quasi-continuously tuned by a Δ-Σ DAC based frequency-locked loop with the power consumption of 1.1mW. The 3.43–4.03GHz FM-UWB transmitter implemented in 0.18μm CMOS consumes the total power of 9.6mW.

15 citations

Journal ArticleDOI
TL;DR: In this paper, it was demonstrated experimentally that the intrinsic modulation response of injection lasers can be modified by reducing mirror reflectivities, which leads to suppression of relaxation oscillation resonance and a reduction of nonlinear distortions up to multi-GHz frequencies.
Abstract: It is demonstrated experimentally that the intrinsic modulation response of injection lasers can be modified by reducing mirror reflectivities, which leads to suppression of relaxation oscillation resonance and a reduction of nonlinear distortions up to multi-GHz frequencies. A totally flat response with a 3-dB bandwidth of 5 GHz was obtained using antireflection coated buried heterostructure lasers fabricated on a semi-insulating substrate. Harmonic distortions were below 40 dB within the entire 3-dB bandwidth. These results are in accord with theoretical predictions based on an analysis which include the effects of superluminescence in the laser cavity.

15 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202322
202242
202128
202044
201962
201855