2022 Volume 19 Issue 13 Pages 20220223
This paper presents a low-cost digital temperature sensor for radio frequency identification (RFID). The proposed sensor utilizes the leakage channel current ratio of different transistors with exponential temperature dependence, which results in ultra-low-power consumption and compact size. Thanks to a dual-differential scheme, it can operate without any extra assistance from a voltage regulator or accurate clock generator. The sensor is fabricated in a standard 55nm CMOS process, and measurement results show that the proposed design achieves an inaccuracy of +0.8/-0.75°C between -20 and 80°C while occupying a silicon area of only 5700µm2. Beneficial from the low total capacitance, the power consumption is 280nW, and the conversion time is 37ms.