STMicroelectronics – Combined humidity and temperature sensor in small, thin package


The HTS221 is a compact sensor which measures relative humidity and temperature.

It includes a MEMS sensing element and a mixed-signal ASIC, which converts the sensor’s measurements to digital values provided via an I2C or serial peripheral interface. It has a user-configurable output data rate of 1Hz, 7Hz or 12.5Hz. At an output data rate of 1Hz, the device draws just 2μA.

The HTS221’s relative-humidity measurements are accurate to ±3.5% over the range of relative humidity between 20% and 80%. Sensitive to very small changes in relative humidity, the HTS221’s sensing element consists of a polymer dielectric planar capacitor structure manufactured using a dedicated ST process.

Guaranteed to operate over a temperature range from -40°C to 120°C, the HTS221 is available in a 2mm x 2mm x 0.9mm land-grid array package with a hole in the top to expose the sensing element to external humidity.


  • Relative-humidity measurement range: 0% to 100%
  • Factory calibrated
  • ±1°C temperature accuracy between 0°C and 60°C
  • Supply-voltage range: 1.7V to 3.6V


  • Air conditioning, heating and ventilation equipment
  • Air humidifiers
  • Refrigerators
  • Wearable devices
  • Smart home automation
  • Industrial automation
  • Respiratory equipment
  • Asset and goods tracking

The X-NUCLEO-IKS01A1 is a MEMS motion and environmental sensor evaluation system. It features the LSM6DS0 three-axis accelerometer/gyroscope, the LIS3MDL three-axis magnetometer, the HTS221 humidity and temperature sensor and the LPS25HB pressure sensor.

Orderable Part Number: X-NUCLEO-IKS01A1