Abstract:A smart temperature sensor is an integrated system consisting of a temperature sensor, its bias circuitry and an analog-to-digital converter (ADC). When manufactured in CMOS technology, such sensors have found widespread use due to their low cost, small size and ease of use. In this paper the basic operating principles of CMOS smart temperature sensors are explained and the stateof-the-art is reviewed. Two new figures of merit for smart temperature sensors are defined, which express the tradeoff between their energy/conversion and their resolution and inaccuracy, respectively. A survey of data published over the last 25 years shows that both these figures of merit usefully bound the performance of state-of-the-art smart temperature sensors.