What is meant b…
7. The reliability of tcxo ppm
What is tcxo ppm?
- When frequency stability of 10 ppm or more is required for a system, temperature compensated crystal oscillators (tcxo) are employed as the frequency reference since a conventional XO (crystal oscillator) or VCXO often cannot meet this requirement (voltage controlled crystal oscillator). “Parts per million” (abbreviated as ppm) area unit of measurement used to indicate extremely low concentration levels.
- The term “temperature-compensated crystal oscillator,” or tcxo refers to a kind of extremely precise crystal oscillator used in situations where temperature stability is crucial. When a consistent frequency is needed yet the working environment is unpredictable enough to change a standard crystal oscillator’s oscillation frequency, tcxo is employed.
What is meant by a ppm?
Parts per million, or ppm, describe the accuracy of crystal clocks and provide a straightforward way to compare the accuracies of various crystal specifications. The ppm, which stands for “parts per million,” is a means of measuring signal error. The amount of inaccuracy in the frequency output of a tcxo (temperature-compensated crystal oscillator) is measured in ppm. The accuracy of the oscillator increases with decreasing ppm.
What are the purposes of tcxo ppm?
A temperature-compensated crystal oscillator, or tcxo ppm, is used when very high stability in a wide variety of temperature environments is required, i.e., when the oscillator’s frequency variation must be small over its whole operational temperature range. When a degree of temperature stability cannot be met by a normal XO (crystal oscillator) or VCXO, tcxo is required (voltage-controlled crystal oscillator). There are two ways to quantify temperature stability: a measurement of how much an oscillator’s frequency changes with temperature.
How effective is a tcxo?
- A rise/fall period of 10ns maximum, a typical duty cycle of 50% 5%, and output enables/disable function is further parameters. At 25 °C, the first calibration tolerance is less than two ppm. The temperature range for storage is -55 to +125°C. The most cost-effective way to establish a steady and accurate reference frequency is to use oscillators that use AT quartz crystal plates, sometimes known as “blanks.”
- However, the accuracy of their frequency depends on the surrounding temperature. Accuracy is greatest at 25°C, which is the ideal temperature. The frequency deviation will alter following a certain feature the farther the ambient temperature deviates from 25°C.
The Performance attributes of tcxo:
A typical tcxo ppm offers a wide range of performance characteristics. The following list of performance metrics includes some of the most popular ones:
- Performance ppm of the tcxo:
The temperature performance of the tcxo ppm is superior to that of a typical crystal oscillator. Figures of improvement between 10 and 40 times are frequently observed. Better than 1.5 ppm figures for the 0 to 70°C temperature range are challenging since they fall into the high precision area, where prices rise dramatically.
- Power dissipation:
Because a tcxo requires extra circuitry, its power consumption will be higher than that of a regular oscillator. In addition, the price is higher. Another thing to remember is that the oscillator won’t steady immediately after startup. Depending on the design, this might take on the order of 100 Ms or perhaps longer.
The tcxo packaging: Depending on how they have been developed and what the end user needs, tcxo can be given in several containers.
The most typical fabrication method is building the circuit on a little printed circuit board that can fit within a solid metal container. This is acceptable when mounted into the main circuit board of the entire piece of equipment. As the crystal is sealed, filling tcxo as the whole package is neither crucial nor even necessary for most applications.
- Output format and level:
The majority of compact oscillator packages produce what is known as a clipped sine wave since many tcxo are used to drive digital circuitry. This may be used to drive a logic circuit. However, passing it through a logic buffer is usually a good idea to ensure it’s suitably square. An open collector circuit is frequently the output. If a sine wave output is necessary, this must be decided upon up front and will restrict the options.
- Power needs:
Depending on the gadget, the actual power needs will vary. Many consume as low as two mA while operating off a 3 V supply; however, this may vary depending on the general type, the brand, and the specific device used.
Application of tcxo ppm:
- For tighter temperature stability that a normal XO or VCXO cannot provide, tcxo is commonly employed in telecommunications applications, GPS positioning, navigation, and timing systems.
- They link a VCXO and an OCXO, the latter of which can be more costly and power-hungry than a standard oscillator. With the emergence of personal portable devices, there was a significant increase in demand for tcxo due to their stability, size requirements, and battery operation.
- The best choice was tcxo ppm, and an excellent example of a gadget that experiences temperature fluctuations throughout its lifespan while being tied to a certain network and never having an impact on its data exchange performance is a mobile phone. To retain functionality, a specific smartphone device’s radio must withstand weather changes, shock and vibrations, and external interference.
It offers a very precise reference frequency that is stable, which may be used to calibrate other timekeeping devices. Another great application for the tcxo ppm is a local oscillator in radio. communications systems where a very steady signal is required. It is an innovative product designed by a team of engineers with years of experience in technology. It has been developed to provide users with a comfortable typing capability. We are dedicated to providing our clients with the highest value products at reasonable prices. All our products are made from high-quality materials and meet international standards. ChipSun is delighted to provide you with the latest and better items. The product you choose is worthwhile to purchase.