The STS21 from Sensirion AG, Staefa, Switzerland, is a digital temperature sensor based on the same chip as the company's SHT2x family of humidity and temperature sensors. The 3 by 3 mm sensor has a temperature measurement range of –40°C to 120°C, with ±0.2°C accuracy over the 5°C–60°C range. Power consumption is 300 µA typ. while measuring and 0.15 µA during sleep mode. The fully calibrated sensor has an I2C interface and provides a digital output.