The HTS221 is a compact relative humidity and temperature sensor. It includes a polymer dielectric planar capacitor structure sensing element and a mixed signal ASIC to provide the measurement information through digital serial interfaces.
HTS221 is available in a small top-holed cap land grid array (HLGA) package, guaranteed to operate over a temperature range from -40°C up to +120°C. It has many uses but some of the main uses include: Air conditioning, heating, ventilation, air humidifiers, refrigerators, wearable devices, smart home products, industrial automation, respiratory equipment and asset tracking. The HS221 also comes pre-calibrated straight from the factory.

Features –
• Tiny 2x2x0.9 mm design
• SPI and I²C interfaces
• 16-bit humidity and temperature data output
• Low power consumption: 2 μA @ 1 Hz ODR
• Selectable ODR from 1 Hz to 12.5 Hz
• High rH sensitivity: 0.004% rH/LSB
• Humidity accuracy: ± 3.5% rH, 20 to +80% rH
• Temperature accuracy: ± 0.5 °C 15 to +40 °C
• 0% to 100% relative humidity range with high sensitivity
• 1.7V to 3.6V supply voltage

Temperature & Humidity Sensors, STMicroelectronics