HTU21D – Proven Digital Humidity and Temperature Sensor for Versatile OEM Applications

The HTU21D is identical to the Sensirion SHT21, providing a compatible alternative for existing designs. Developers looking for a replacement for the SHT21 can use the HTU21D with minimal design changes.

Each sensor is individually calibrated, temperature-compensated, and tested. This ensures high measurement accuracy of typically ±2 %RH as well as precise temperature measurement over a range of -40 °C to 125 °C. The humidity measurement range covers 0 to 100 %RH.

The digital I²C interface enables easy integration into existing systems and allows further processing of measurement data with cost-effective microcontrollers. The resolution can be adjusted depending on the application, enabling an optimal trade-off between accuracy and conversion time.

Thanks to its very low power consumption of typically 2.7 µW, the HTU21D is particularly suitable for battery-powered applications. In addition, the sensor can provide information on battery status, making it ideal for mobile and energy-efficient systems.

Reliable data transmission is ensured by an integrated CRC check. In addition, an electronic identification code can be read via the I²C bus, enabling traceability of each sensor. The sensor is housed in a compact, reflow-solderable DFN package (3 x 3 x 0.9 mm³) and is optionally available with a PTFE filter membrane that provides additional protection against dust and moisture.
Typical applications of the HTU21D include HVAC systems, medical technology, and building automation, as well as household appliances and mobile devices such as smartphones and tablets.

Due to its compact design, simple digital interface, and high measurement stability, the HTU21D is ideal for fast and straightforward integration into existing designs. This reduces development effort and time-to-market, making the sensor a reliable solution for series production.

Key Features of the HTU21D:

• Humidity range: 0 to 100 %RH
• Temperature range: -40 to 125 °C
• Typical accuracy: ±2 %RH
• Digital I²C interface
• Very low power consumption
• Adjustable resolution
• Compact DFN package

Further information, datasheets, and application notes are available at www.amsys.de.