The SHT1x series of surface mount digital humidity & temperature sensors are CMOSens® based with a tiny footprint. Both the humidity and temperature sensors contained are coupled to a 14-bit ADC and a serial interface circuit. Humidity is measured by a capacitive sensor whilst temperature is measured by a band-gap sensor.
The SHT1x sensors also contain a version 4 silicon chip with an amplifier, A/D converter, OTP memory and a digital interface.

CMOSens® based technology
2-wire serial interface
Fully calibrated
Digital output
Low power
Long term stability
Great signal quality
Not sensitive to extraneous interruption

Temperature & Humidity Sensors, Sensirion