This part is a kind of semiconductor called HTU21D.

Function of this product has Digital Relative Humidity sensor.

Manufacturers : Measurement

Image and pinout :

Some of the text within the PDF file :

HTU21D(F) Sensor Digital Relative Humidity sensor with Temperature output       DFN type package Relative Humidity and Temperature Digital Output, I²C interface Fully calibrated Lead free sensor, reflow solderable Low power consumption Fast response time DESCRIPTION The HTU21D(F) is a new digital humidity sensor with temperature output by MEAS. Setting new standards in terms of size and intelligence, it is embedded in a reflow solderable Dual Flat No leads (DFN) package with a small 3 x 3 x 0.9 mm footprint. This sensor provides calibrated, linearized signals in digital, I²C format. HTU21D(F) digital humidity sensors are dedicated humidity and temperature plug and play transducers for OEM applications where reliable and accurate measurements are needed. Direct interf [ ... ]

HTU21D PDF Datasheet Download