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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17 Jul 2001TL;DR: In this article, the presence or absence of oscillation or a failure of the varactor diode or oscillation device is detected by a detection signal, for example, from the variable reactance element (VRE) as monitored by a voltage monitor, and/or from the oscillation devices, as monitoring by a current sensing device.
Abstract: A voltage controlled oscillator, a voltage controlled oscillator device, and a radar device provided therewith which can detect when the oscillation frequency becomes uncontrollable. According to one embodiment, a Gunn or other oscillation device is connected to a main line and a varactor diode which is a variable reactance element is connected between the main line and a sub line to constitute a voltage controlled oscillator. A control voltage is applied to the varactor diode via a switching circuit, and the presence or absence of oscillation or a failure of the varactor diode or oscillation device is detected by a detection signal, for example, from the varactor diode as monitored by a voltage monitor, and/or from the oscillation device, as monitored by a current sensing device.
7 citations
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TL;DR: A new Switched Capacitor (SC) Capacitance-to-Digital Converter (CDC) is presented in this paper, which exhibits a high-level of insensitivity to interference, by virtue of the conversion mechanism itself.
Abstract: A new Switched Capacitor (SC) Capacitance-to-Digital Converter (CDC) is presented in this paper. Its output exhibits a high-level of insensitivity to interference, by virtue of the conversion mechanism itself. The proposed scheme is a combination of an SC relaxation oscillator and an integrating type analog-to-digital converter (ADC). Its conversion time is independent of the measurand and hence can be set, such that it is an integral multiple of the interference period, unlike in a dual-slope ADC where the de-integration time is a function of the measurand. The final output is proportional to the number of transitions in the oscillator output, which is directly proportional to the value of the sensor capacitance and has negligible sensitivity to the presence of the interference signal. The proposed scheme has been realized and tested as a hardware prototype unit. The non-linearity of the scheme was found to be 0.4%, and the resolution, in terms of the effective number of bits (ENOB), was 11.13, when tested, with sensor capacitance varied from 10 to 32.5 pF. The studies conducted to evaluate the effect of capacitively coupled interference to the sensitive node on the CDC showed that it is negligible for a wide range of magnitude.
7 citations
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21 Oct 1986TL;DR: In this paper, a noncontact electronic switching arrangement is provided with an oscillator which can be damped by external objects, such as a reference voltage comparator at the output of the oscillator, delivering at a Schmitt trigger output, pulse signals to a retriggerable time delay stage, or a shift register, which are connected to an exclusive-OR stage.
Abstract: A noncontact electronic switching arrangement is provided with an oscillator which can be damped by external objects. In accordance with the invention, the oscillator can be excited externally and is coupled to an evaluation circuit and an amplifier. A frequency control, which may consist of a phase-locked loop module, is connected to the externally excited resonant circuit of the oscillator. A reference voltage comparator at the output of the oscillator delivers at a Schmitt trigger output, pulse signals to a retriggerable time delay stage, or a shift register, which are connected to an exclusive-OR stage. The functioning of the exclusive-OR stage can be programmed. The arrangement is particularly useful as a limit or end switch for machine tools.
7 citations
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01 Aug 1997
TL;DR: In this article, an ultrasonic generator circuit is described which comprises a resonant LC power oscillator circuit for driving a transducer, with feedback provided via a feedback transformer whose primary is connected in the resonant circuit, the secondary of the feedback transformer being connected to a feedback signal converter which, in dependence upon feedback current induced in the secondary, applied a feedback voltage to the input of the voltage controlled switching element.
Abstract: An ultrasonic generator circuit is described which comprises a resonant LC power oscillator circuit for driving an ultrasonic transducer, the resonant circuit comprising a voltage controlled switching element (an integrated gate bipolar transistor is preferred), and feedback being provided via a feedback transformer whose primary is connected in the resonant circuit, the secondary of the feedback transformer being connected to a feedback signal converter which, in dependence upon feedback current induced in the secondary of the feedback transformer, applied a feedback voltage to the input of the voltage controlled switching element (Fig. 6).
7 citations
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12 Nov 2012TL;DR: The design of an area-efficient CMOS relaxation oscillator for low power applications is described, which includes a temperature compensation scheme based on the matching of bias current circuit and oscillator inverters threshold voltages that provides a clock frequency stable over the entire temperature range.
Abstract: The design of an area-efficient CMOS relaxation oscillator for low power applications is described. Its architecture includes a temperature compensation scheme based on the matching of bias current circuit and oscillator inverters threshold voltages that provides a clock frequency stable over the entire temperature range (−40µ C∼ 125µ C). The circuit is the auto-wakeup IP core of a microcontroller family for consumer applications, occupies an area of 0.03mm2 in a 0.5µm CMOS process, operates from 1.5V to 5.5V, and consumes 800nA.
7 citations