Sensiron claims it has created the smallest digital humidity and temperature sensor with its SHT21. It measures 3x3x1mm. It consists a sensor chip encapsulated in a DFN 3-0 package. The package is over-moulded except for the humidity sensing area. Over-moulding also protects against aging and ambient impact, such as condensation and harsh environments, and thus yields outstanding long-term stability. The sensor is calibrated and has a true I²C digital interface. Analogue output modes, such as PWM, are available on request. The digital communication mode enables low power consumption: A value in the range of 3μW at normal operation is achieved and may be lowered further by increasing the measurement interval. Typical sensor accuracy is ±2% RH over 20 to 80% RH and ±0.3°C over 25 to 42°C. The sensor has been qualified in accordance with automotive standard AEC-Q100. An extended quality assurance programme guarantees low PPM values. A scan path routine enables detailed sensor quality checking, while individual detailed tracking information on the chip can be read out by a simple command. The sensor is reflow solderable without any degradation of sensor performance. Packaging is tape and reel.
