Low-power frequency-conversion based temperature sensor for long-range passive RFID sensor applications.

A low-power frequency-conversion based temperature sensor interface optimized for passive UHF RFID applications have been designed and implemented. The interface is based on a reference capacitor that is charged by a temperature dependent current and discharged by a hysteresis loop. The circuit has been implemented in a standard CMOS 180nm process. The post-layout simulations show that the presented architecture is able to compensate for variations on the bandgap reference and cover a wide temperature range (140oC) with minimum active area (0:019mm2), reduced power consumption (-= 6:5gammaW), and reduced effect of PVT variations, accomplishing the design objectives