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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Patent•
05 Jun 2020
TL;DR: In this article, a relaxation oscillator is configured to switch between a first clock signal having a negative value as a first-order temperature coefficient of an oscillation period, and a second clock signal with a positive value as firstorder temperature coefficients of a first order temperature coefficient, based on a signal from the counter.
Abstract: Provided is a relaxation oscillator that is very small in temperature deviation of an oscillation period The relaxation oscillator includes an oscillation circuit, a variable frequency divider, and acounter The oscillation circuit is configured to switch between a first clock signal having a negative value as a first-order temperature coefficient of an oscillation period, and a second clock signal having a positive value as a first-order temperature coefficient of an oscillation period, based on a signal from the counter, and to output the switched-to clock signal as a third clock signal The variable frequency divider is configured to divide the frequency of the third clock signal that is output from the oscillation circuit, and to output the frequency-divided third clock signal as a clock signal The counter is reset by the clock signal
TL;DR: In this article , a temperature sensor based on temperature-frequency conversion using 180 nm CMOS technology is proposed, which consists of a proportional-to-absolute temperature (PTAT) current generating circuit, a relaxation oscillator with oscillation frequency proportional to temperature (OSC-PTAT), and a relaxation OSC-CON, and a divider circuit cascaded with D flip-flops.
Abstract: This paper proposes a temperature sensor based on temperature-frequency conversion using 180 nm CMOS technology. The temperature sensor consists of a proportional-to-absolute temperature (PTAT) current generating circuit, a relaxation oscillator with oscillation frequency proportional to temperature (OSC-PTAT), a relaxation oscillator with oscillation frequency independent of temperature (OSC-CON), and a divider circuit cascaded with D flip-flops. Using BJT as the temperature sensing module, the sensor has the advantages of high accuracy and high resolution. An oscillator that uses PTAT current to charge and discharge capacitors to achieve oscillation, and utilizes voltage average feedback (VAF) to enhance the frequency stability of the oscillator is tested. Through the dual temperature sensing process with the same structure, the influence of variables such as power supply voltage, device, and process deviation can be reduced to a certain extent. The temperature sensor in this paper was implemented and tested with a temperature measurement range of 0–100 °C, an inaccuracy of +0.65 °C/−0.49 °C after two-point calibration, a resolution of 0.003 °C, a resolution Figure of Merit (FOM) of 6.7 pJ/K2, an area of 0.059 mm2, and a power consumption of 32.9 μW.
24 Apr 2022
TL;DR: In this article , a method to measure the relaxation rates in Rubidium (Rb) Pulsed Optically Pumped (POP) vapor cell frequency standards is described. But the method is not suitable for the case of high temperature.
Abstract: SummaryWe describe a method to measure the relaxation rates in Rubidium (Rb) Pulsed Optically Pumped (POP) vapor cell frequency standards. By means of repeated spectroscopy measurements with varying Ramsey time, we show how to extract multiple estimations of the population and coherence relaxation rates of interest, which yields satisfying statistical error. The method can be applied using standard clock spectroscopy methods and equipment.
01 Oct 2017
TL;DR: In this paper, a 27.6 MHz 297 μW relaxation oscillator is presented by using an 180-nm CMOS technology, which employs an adjustable temperature compensation feedforward scheme, in which the charging current can be set steady by a four-bit digital trimming signal.
Abstract: A 27.6 MHz 297 μW relaxation oscillator is presented in this paper by using an 180-nm CMOS technology. The proposed oscillator employs an adjustable temperature compensation feedforward scheme, in which the charging current can be set steady by a four-bit digital trimming signal. We have demonstrated a frequency variation lower than 33.5 ppm/°C which could be close to 0 ppm/°C in theory if the precision is high enough. In practical production, it is effective to calibrate the mismatching and deviation of fabrication because of the novel adjustable temperature compensation scheme.
Patent•
02 Jun 1998
TL;DR: In this paper, the authors derived a constant voltage charge packets for the size (and / or phase) indicates the size of the lamp AC voltage from the AC voltage lamp, and passed these charge packets to a frequency-determining capacitor of the relaxation oscillator, designed as an oscillator.
Abstract: Ein elektronisches, fremdgesteuertes Vorschaltgerat (1) weist einen Steueroszillator (18) auf, der uber eine Wechselrichterbrucke (5) und einen Resonanzkreis eine Leuchtstofflampe (2) speist. An electronic, externally controlled ballast (1) has a control oscillator (18) via an inverter bridge (5) and a resonant circuit supplies a fluorescent lamp (2). Zur Konstanthaltung der Spannung werden aus der Lampenwechselspannung Ladungspakete abgeleitet deren Grose (und/oder Phasenlage) die Grose der Lampenwechselspannung kennzeichnet. To maintain a constant voltage charge packets are derived for the size (and / or phase) indicates the size of the lamp AC voltage from the AC voltage lamp. Die Ladungspakete werden auf einen frequenzbestimmenden Kondensator (22) des als Kipposzillator ausgelegten Oszillators (18) geleitet, womit eine Spannungsregelung erzielt wird. The charge packets are passed to a frequency-determining capacitor (22) of the relaxation oscillator, designed as an oscillator (18), whereby a voltage regulation is obtained. Diese ist robust, einfach, vermeidet unerwunschte Regelschwingungen und ergibt eine gute Spannungskonstanz. This is robust, simple, avoids unwanted vibrations and usually results in a good voltage stability.