Novel time-domain CMOS temperature sensor for passive RFID Tag

This work presents a time-domain sensor in which the ratio between two temperature dependent signals is measured. This signals are generated within the sensor in order to increase its sensitivity when compared to traditional approaches in which one of them is temperature invariant and generated externally. In this way, the sensor is autonomous and can be integrated in any system, without the need of a reference.The resulting sensor was integrated with a RFID Tag in a 130 nm technology; the chip validation was performed for temperatures between 20 °C and 60 °C, yielding sensor linear response and a power consumption of 80 nW @ 60 °C and 10 samples per second.