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HTU21D Digital Humidity/Temperature Sensor


The new digital sensor HTU21D is a fully self contained capacitive humidity sensor combined with a bandgap temperature sensor. Every product is individually calibrated, compensated and finally tested. The HTU21D sensors are dedicated humidity and temperature plug and play sensors for OEM applications where reliable and accurate measurements are needed. HTU21D sensors are characterized by a 0 – 100% RH-range and by an extended temperature range. The humidity and tempera­ture digital outputs are in an I²C format and suitable for all micro-controllers. The resolution of HTU21D sensor can be changed by command (8/12bit up to 12/14bit for RH/T), whereby the measurement time and the current consumption can be modified. With the very low power consumption the sensors are dedicated for battery powered applications. Furthermore, low battery can be detected and a checksum improves communication reliability.

Humidity and temperature response time as well as the recovering time (from condensing humidity) are in the range of a few seconds.

Lot identification is printed on the sensor and an electronic identification code is stored on the chip – which can be read out by command.

Embedded in a reflow solderable Dual Flat No leads (DFN) package of 3 x 3mm foot print with 0.9mm height the combined humidity and temperature sensor is designed for high volume and cost sensitive applications with tight space constraints. With made improvements and the miniaturization of the sensor the performance-to-price ratio has been improved.

Optional PTFE filter/membrane (F) protects the HTU21D against dust, water immersion as well as against contamination by particles.

AMSYS also offers the HTU21D mounted on a PCB with pins for prototyping and batch production (PHTU21) to faciliate the manual mounting of the sensor.

  • Wide humidity range 0-100%RH
  • Wide temperature range -40-125°C
  • Digital I²C- interface
  • Humidity accuracy ±2%RH typical
  • 1.5 - 3.6Volt operation
  • Low power dissipation typ. 2.7μW
  • Instantaneous desaturation after long periods in saturation phase
  • Compatible with automatized assembly (reflow) processes,
  • Electronical identification code
  • Small dimensions (DFN-package)
  • Adjustable resolution
  • RoHS suitable and Pb free
  • Automotive (passenger compartment)
  • Home Appliances
  • Medical Equipment
  • Printers and copiers
  • Humidifiers and HVAC systems
  • Building Automation
  • Weather monitoring
  • Security systems
  • Multi media - smart phone, tablet


For information according to prices, delivery dates and sample ordering or for technical questions please contact

Amsys reserves the right for changes concerning dimensions, technical data and other details without previous announcement.