The SHT21 from Sensirion AG, Staefa, Switzerland, is a 3 by 3 by 1.1 mm device that packages a digital humidity and temperature sensor into an overmolded DFN 3-0 package, leaving only the humidity sensing area exposed. This protects against aging and ambient impact. Sensor accuracy is ±2% RH typ. over 20%–80% RH and ±0.3°C over 25°C–42°C. Current draw is 3 µW at normal operation. The fully calibrated device offers an I2C interface; analog output modes are available on request. The sensor is AEC-Q100 qualified.