Following the successful launch of the world’s smallest digital humidity and temperature sensor in 2010, the fully calibrated sensors of the SHT2x family have already won design slots in many applications. Now Sensirion has again significantly improved the temperature specifications of the standard SHT21 version.
The temperature range for the tightest typical accuracy of ±0.3°C, originally specified as 25 to 42°C, has been enlarged to the range of 5 to 60°C. In addition, accuracy at the limits of the measuring range has been distinctly improved.
This enables customers to benefit from significant product improvements with unchanged pricing. Along with outstanding longterm stability and low power consumption, very high precision can now be achieved over a temperature range that is significant for many applications. According to product manager Vincent Hess, “this makes the SHT21 specifically suitable for applications with very stringent temperature accuracy requirements.”
SHT21 consists of a newly designed, sophisticated sensor chip encapsulated in a DFN 3-0 package. With this encapsulation the chip is completely over-molded, except the humidity sensing area. In this way, the components size is reduced to a 3x3- mm footprint with 1.1-mm height. Additionally, over-molding provides excellent protection against aging and ambient impact, such as condensation and harsh environments, and thus yields outstanding long-term stability. The SHT21 is fully calibrated and provides an I2C digital interface. Analog output modes (such as PWM) are available on request. The digital communication mode enables superb low power consumption: A value in the range of 3ìW at normal operation is well achieved. Provided on tape & reel, the reflow solderable SHT21 is suitable for high volume applications.
Furthermore, the sensor is qualified in accordance with automotive standard AEC-Q100 and an extended quality assurance program guarantees low PPM values. Free samples of the SHT21 humidity and temperature sensor can be ordered at www.sensirion.com/mysht21.