humidity and temperature sensor HTU21D by AMSYS

humidity / temperature sensor HTU21D

humidity and temperature sensor HTU21DF by AMSYS

humidity / temperature sensor HTU21DF
(with PTFE filter membrane)

HTU21D and HTU21D(F)

The digital HTU21D OEM sensor is a combination of capacitive humidity sensing element and temperature sensor. Each sensor is individually calibrated, compensated for and tested.

The humidity can be measured within a range of 0 to 100% RH. The temperature sensor is designed for a range of -40 to 125°C.

The outputs for humidity and temperature in I²C format are suitable for further data processing using simple, inexpensive microcontrollers. The resolution of the HTU21D can be programmed (8/12 bits to 12/14 bits RH/T).

As the sensor has a low power consumption it is suitable for battery operation, with information on the current battery level provided.

Secure data transmission is ensured by a CLC or cyclic redundancy check. Humidity and temperature signal response times and the recovery time (following full saturation) are within a range of a few seconds.

The HTU21D’s semiconductor components are mounted in a (reflow) solderable 3 x 3 x 0.9 mm3 DFN chip package (dual-flat no-lead).

Variants of the HTU21D

The HTU21D is also available as the optional HTU21D(F) with a PTFE filter membrane to protect it from dust, liquid and contamination.
Pre-assembled sensors on circuit boards in the HTU21D series – the PHTU21D – are also available which can be used as development modules for the OEM humidity sensors.
Analog humidity sensor HTU(F)353X  or the digital HTU(F)383X version are also provided as ready-to-use humidity sensor modules based on the HTU.


  • Humidity range of 0 to 100% RH
  • Temperature range of -40 to +125°C
  • Digital I²C interface
  • Accuracy of ±2% RH
  • Supply voltage of 1.5 to 3.6 V
  • Short signal times
  • Settable resolution
  • Fast recovery time after saturation
  • Electrical ID code
  • Low power dissipation of 2.7 μW
  • Small DFN package
  • RoHS and REACH compliant


  • Car cabins
  • Household appliances
  • Medical equipment
  • Electrical devices
  • Humidifiers/dehydrators and driers
  • Air conditioning systems
  • Weather stations
  • Security systems
  • Multimedia devices (smartphones, tablets)


For information on prices and delivery times or if you have any technical questions, please contact