Application of crystal oscillator in "smart three meters"
1. Intelligence and trend of "civil three meters"
"Civil three meters" usually refer to water meters, electricity meters and gas meters used in households. These three meters play an important role in daily life, involving the use and measurement of water, electricity and gas in households. Water meters are used to measure household water consumption; electricity meters are used to measure household electricity consumption; gas meters are used to measure household gas consumption.
The accuracy of "civil three meters" is directly related to the economic interests and safety of the family. With the development of science and technology, everything is moving towards intelligence, and meters are no exception. Compared with the traditional "civil three meters", "smart three meters" (smart water meters, smart electricity meters, smart gas meters) have more diverse functions, making the management of water, electricity and gas more convenient and efficient, bringing better economic benefits and safety guarantees to families and society.
With the acceleration of my country's urbanization process, the development of rural water affairs and the accelerated advancement of urban water affairs informationization transformation, the policy environment of the smart water meter industry has become increasingly favorable, which has promoted the rapid growth of the market. It is expected that by 2027, the market size of my country's smart water meter industry will increase significantly. At the same time, due to the country's requirement for regular rotation of meters, it has recently entered an intensive replacement period. It is expected that the market for smart metering instruments may reach tens of billions in the next few years.
2. The role of crystal oscillator in "smart three meters"
Crystal oscillator (crystal oscillator) can send stable and accurate clock signals, and plays an important role in the circuit design of "smart three meters" (MCU, analog-to-digital conversion module, transmission module, etc.), ensuring the accuracy of data and the synchronization of communication. For example, the real-time clock RTC module must be equipped with a 32.768KHz crystal oscillator; the MCU main control module is generally equipped with 24MHz, 24.576MHz crystal oscillators, etc.
Schematic diagram of the modules of smart meters
The specific functions of the crystal oscillator in the "smart three meters" include:
The circuit design of the "smart three meters" requires the clock signal sent by the crystal oscillator for synchronization. If the accuracy or stability of the clock signal is insufficient, it may cause remote data transmission loss or inaccurate data measurement, which will have a great impact on the economic interests and safety of residents. Therefore, the "smart three meters" have high requirements for crystal oscillators. Conventional designs require crystal oscillator accuracy ≤ ±10PPM, and some applications even require crystal oscillator accuracy ≤ ±5PPM; at the same time, there are certain performance requirements for the operating temperature, reliability, aging rate, etc. of the crystal oscillator to ensure that the metering equipment can operate stably in various environments.
As a key component in the "smart three meters", the crystal oscillator provides a stable working environment for it, ensuring the accuracy of measurement and the reliability of data communication. The combination of these technologies has promoted the development of traditional meters towards intelligence and digitization, and is an important part of smart city construction.
3. YXC recommends "smart three meters" solution
Common frequencies of "smart three meters": 32.768K, 8M, 12M, 16M, 24M, 24.576M, 25M, 38.4M, etc.
Based on the requirements of "smart three meters" for clock equipment, the following YXC crystal oscillator solutions are recommended:
· 32.768KHz resonator
Currently, the mainstream of "smart three meters" solution adopts 32.768KHz resonator with 3.2*1.5 patch type or 2.0*6.0 plug-in type. In response to the actual application needs of smart meters, YXC also provides 32.768KHz patch product YST311S with 3.2*1.5 package, which reduces production costs while maintaining high performance parameters and has higher cost performance.
YST311S product diagram
· MHz resonator
In the "smart three-meter" application, the MHz resonator mainly adopts 3225 size, and some have miniaturization requirements of 2016 and 2520
· CMOS oscillator
The "smart three-meter" with higher intelligence requirements has higher requirements for clock frequency equipment, and needs to have high precision and high stability. The design requirements can be met by fixed frequency or pre-programmed oscillators.
For applications with high precision requirements such as billing meters, YXC provides the RTC product YSN8025, which is a high-precision RTC (accuracy of ±3.4ppm) and has a built-in 32.768KHz crystal oscillator, providing solutions for high-precision metering application scenarios.
YSN8025 product diagram