STS21 Digital Temperature Sensors Sensirion STS21 Digital Temperature Sensor offers superior performance and a space saving footprint. Embedded in a reflow solderable DFN package of 3 x 3mm footprint and 1.1mm height, it provides calibrated, linearized signals in digital, I2C format. Using CMOSens® technology, Sensirion STS21 offers superior performance and reliability. The ±0.2°C temperature specification allows for implementation of the STS21 in applications with high demands on temperature accuracy. The resolution of STS21 can be changed by command (11-bit up to 14-bit), low battery can be detected, and a checksum helps to improve communication reliability.