humidity and temperature sensor HTU21P by AMSYS

humidity and temperature sensor HTU21P

 HTU21PF - humidity and temperature sensor with filter-membrane by AMSYS

humidity and temperature sensor HTU21PF
(mit PTFE Filtermembran)

HTU21P and HTU21P(F)

The HTU21P OEM sensor is a combination of capacitive humidity sensing element and temperature sensor. Each sensor is individually calibrated, compensated for and tested.

The basic frequency is a 120-Hz PWM signal which enables an analog DC output signal to be generated through a suitable lowpass filter.

The sensor has a wide measurement range for relative humidity of between 0 and 100% RH. The accuracy varies from ±2% between 20 and 80% RH (@ 25°C) to up to 5% in the extended range. Temperature is detected with an accuracy of ±0.3°C (@ 25°C) within a spectrum of -40 to +125°C. The resolution for relative humidity and for temperature is 10 and 12 bits respectively.

Following full saturation the HTU21P is again operational after approximately 10 seconds.

The sensor is supplied in a (reflow) solderable 3 x 3 x 0.9 mm³ DFN chip package (dual-flat no-lead), making it suitable for sensor systems with a small footprint.

Variants of the HTU21P

The HTU21P is also available as the optional HTU21P(F) with a PTFE filter membrane to protect it from dust, liquid and contamination.
Pre-assembled digital 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
  • Analog PWM output signal
  • Accuracy of ±2% RH
  • Supply voltage of 1.5 to 3.6 V
  • Short signal times
  • Fast recovery time after long saturation periods
  • 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

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