The Design And Implementation Of Wireless Sensing System-on-Chip Based On Near Field Communication

Sensing technology is the important way to obtain information in modern society. The demand for sensing system is also increasing as the modern science and technology continue to develop, especially the appearance of the wireless sensing technology. With the advantages of high efficiency, reliability, stability, long lifecycle in poor working conditions, wireless and passive sensing has been applied in various fields including environment monitoring, automatic operation and so on, attracting many domestic and foreign research institutions.In this paper, a pair of integrated circuits for wireless monitoring of diverse analog quantities, such as temperature, pressure, humidity, etc., is designed and fabricated in low-cost CMOS process. Up to three switch quantity ports are simultaneously integrated, enabling the chipset to monitor the change of static binary voltages, and provide additional control functions. With one reader and one sensor chips, the chipset works on the principle of near field communication (NFC) which is similar to traditional NFC-based radio frequency identification (RFID) systems. The difference is that the integrated phase lock loop (PLL)'s operating frequency range is significantly extended from 8 to 12 MHz, providing a robust self-adaptive stability in impedance-varying environments. Besides, a built-in 12-bit, self-calibrated analog to digital convertor (ADC) improves the precision significantly.The fabricated chipset has been successfully characterized and applied to contactless temperature measurement and switch's on-off detection in a mass-produced household appliance product, showing great potential in various industrial and instrumental applications.