Sensirion's digital humidity and temperature sensors, SHT2x sensors, are constructed of a high-performance sensor chip encapsulated in a DFN 3-0 package. The chip is completely over-moulded, except the humidity sensing area, which reduces the footprint to just 3x3x1.1mm. The over-moulding also protects against ageing and ambient impact, such as condensation and harsh environments, and thus yields outstanding long-term stability. The sensor is calibrated and has an I2C digital interface. Analogue output modes, such as PWM, are available on request. The digital communication mode enables low power consumption whereby a value in the range of 3μW at normal operation is achieved and may be lowered further by increasing the measurement interval. The typical sensor accuracy of the standard version SHT21 is ±2% RH over 20 to 80% RH and ±0.3°C over 5 to 60°C. The high-precision version, the SHT25 achieves a typical accuracy of 1.8% RH (at 25°C) for relative humidity and 0.2°C for temperature. Both versions have 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 to be read out by a simple command.
