The Si7005 Temperature/Relative Humidity (RH) Sensor advances the state of the art in sensors by combining a mixed-signal integrated circuit based on standard CMOS with the proven technique of measuring humidity using a polymer dielectric. It relies on the well-known behavior of certain polyimides that change their electrical properties (permittivity) with changes in moisture content. The Si7005 integrates a capacitor with a polymer dielectric layer; changes in moisture (RH) are sensed as a capacitance change. It is completely monolithic, making it rugged and reliable. The monolithic construction also facilitates its small size, 4 mm x 4 mm square and less than 1 mm high. It is one of the lowest power devices of its kind, making it ideal for battery-powered applications. It consumes only 2 µA on average at 1 measurement/second. In the case of discrete sensors, the user is required to calibrate each completed sensor circuit themselves. Each Si7005 is factory calibrated and interchangeable. Many RH sensors are rather delicate and not completely compatible with typical PCB assembly flows (tape-and-reel, pick-and-place, solder reflow, etc.) The Si7005 works with typical SMT manufacturing flows. Since the sensor element must be exposed to the environment (air), RH sensors are subject to damage and contamination, especially during PCB assembly. Silicon Labs offers an optional, factory-installed protective cover that protects the sensor over the product's entire lifetime.