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Build Your Own Arduino Board from Scratch
Published in Anudeep Juluru, Shriram K. Vasudevan, T. S. Murugesh, fied!, 2023
Anudeep Juluru, Shriram K. Vasudevan, T. S. Murugesh
An electronic oscillator is nothing but an electronic circuit that produces a periodic, oscillating electronic signal. Some of the commonly used electronic oscillators are RC oscillator and LC oscillator. These oscillators can be used to generate both low and high frequencies, but the main problem with these oscillators is that their oscillation frequency varies with temperature, power supply voltage or even with a slight change in component values. So, crystal oscillators are used in applications where high accuracy and stability are required. These are used in clocks, microcontrollers and in most of the ICs. These oscillators can generate frequencies from a few kilo Hz to 100s of mega Hz. A crystal oscillator is also an electronic oscillator that uses a vibrating crystal of piezoelectric material for generating an electrical signal with constant frequency. There are many naturally occurring crystals with the piezoelectric property like Rochelle salt, Quartz, Tourmaline, etc. Among them Quartz is the most commonly used crystal because of its easy availability, low cost, mechanical strength and piezoelectricity compared to other crystals. Crystal oscillators work on the principle of inverse piezoelectric effect, a property in which the shape of the material slightly changes under an electric field. The Arduino Uno board uses a 16âMHz crystal oscillator as shown in Figure 21.3 for providing clock signals to the microcontroller.
Introduction to Customized Board with 8051 Microcontroller and NuttyFi/ESP8266
Published in Anita Gehlot, Rajesh Singh, Praveen Kumar Malik, Lovi Raj Gupta, Bhupendra Singh, Internet of Things with 8051 and ESP8266, 2020
Anita Gehlot, Rajesh Singh, Praveen Kumar Malik, Lovi Raj Gupta, Bhupendra Singh
A crystal oscillator is an electronic oscillator circuit, which is used for the mechanical resonance of a vibrating crystal of piezoelectric material. It will create an electrical signal with a given frequency. This frequency is commonly used to keep track of time for example: wrist watches are used in digital integrated circuits to provide a stable clock signal and also used to stabilize frequencies for radio transmitters and receivers. Quartz crystal is mainly used in radio-frequency (RF) oscillators. Quartz crystal is the most common type of piezoelectric resonator; in oscillator circuits we are using them so it became known as crystal oscillators. Crystal oscillators must be designed to provide a load capacitance, as shown in Figure 4.6.
A Cost-Effective TAF-DPS Syntonization Scheme of Improving Clock Frequency Accuracy and Long-Term Frequency Stability for Universal Applications
Published in Fei Yuan, Krzysztof Iniewski, Low-Power Circuits for Emerging Applications in Communications, Computing, and Sensing, 2018
Liming Xiu, Pao-Lung Chen, Yong Han
A crystal oscillator is the dominant frequency source used in commercial systems, primarily due to its low cost and good short-term frequency stability. Its output frequency, however, is temperature dependent, which can vary more than 100 ppm in low and high temperature extremes. A solution to this problem is temperature compensation by employing a temperature sensor in the system. A BJT-based sensor is known to achieve the best combination of accuracy and energy efficiency. It can be integrated in a system to provide temperature readings and subsequently to direct the frequency correction. An example is presented in [18]. A thermistor-based sensor can achieve higher temperature resolution. A Wien-Bridge-based thermistor temperature sensor is presented in [28]. A time-domain temperature sensor (TDTS) could be implemented in digital fashion and is thus low cost, low power, and more robust against process variation [29â32]. It has also been used to compensate crystal oscillators [33]. These temperature-sensing techniques can be readily used with our TAF-DPS scheme to counteract temperature-induced frequency variation, as depicted in Figure 5.19.
Simulation and evaluation of pulse-coupled oscillators in wireless sensor networks
Published in Systems Science & Control Engineering, 2018
Yan Zong, Xuewu Dai, Zhiwei Gao, Richard Binns, Krishna Busawon
The clock of a sensor node usually is constructed from hardware and software components. To be specified, the clock module of a WSNs node consists of (i) a crystal oscillator ticks at a specified frequency; (ii) a counter (or a chain of counters), counts the number of ticks generated by the crystal oscillator. Physically, the output of a crystal oscillator is periodic sinusoidal or square waves, while, this output can be converted to a count value plus one per clock cycle through the process the counter which is digital timing circuit (Zong, Dai, & Gao, 2017), and this count value can be used to indicate the time by comparing and converting to the count value. The output of a crystal oscillator is generally called the physical clock, while, the cumulative count value of the counter register is called the software clock. To avoid the physical clock discontinuity, it is recommended to apply the time synchronization algorithms to software clock, rather than the physical clock (Bojic & Nymoen, 2015), and the time synchronization algorithms in this paper are therefore to adjust the software clock.