The HTU21D is a compact, high-precision digital sensor that measures both humidity and temperature. It offers a humidity range of 0–100% RH with ±2% accuracy and a temperature range of -40°C to 125°C with ±0.3°C accuracy. Featuring a low-power design and I²C interface, it's ideal for battery-powered applications. Its small 3×3×0.9 mm DFN package makes it suitable for space-constrained environments like HVAC systems, medical devices, and IoT applications.