IC advances the state of the art in RH sensing

IC advances the state of the art in RH sensing

The Si7005 digital relative humidity (RH) and temperature “sensor-on-a-chip” solution combines a mixed-signal IC manufactured on standard CMOS with a proven technique of measuring humidity using a polymer dielectric film. The sensor is ideal for applications that monitor or control humidity and temperature including automotive climate control and defogging, HVAC, refrigeration, weather stations, food processing, printers, asset tracking, and medical instruments such as nebulizers, oxygen concentrators and respiratory therapy equipment.

Traditional approaches to RH sensing use discrete resistive and capacitive sensors, hybrids and MCMs. These legacy approaches suffer from high BOM cost and component count, large footprints, manufacturing challenges and the need for labor-intensive customer calibration. In contrast, the single-chip Si7005 humidity sensor is smaller, more reliable, and much easier to design in and use than traditional discrete/module solutions.

This monolithic CMOS IC integrates temperature and humidity sensor elements, an I2C interface, on-chip signal conditioning and calibration onto a rugged and reliable single compact 4 x 4 mm QFN package. Features include a relative humidity accuracy of ±3% typical and ±4.5% max, a temperature accuracy of ±0.5 °C typical and ±1 °C max, and a low power consumption of 240 μA during relative humidity conversion.

This humidity sensor is a “plug-and-play,” factory-calibrated RH and temperature sensing solution. The device’s digital output and factory calibration frees the developer from having to calibrate the sensor and also makes Si7005 sensors completely interchangeable. No software/firmware update or recalibration effort is required to change from one sensing unit to another.($3.64 ea/10,000 — available now)

By Christina Nickolas

Silicon Laboratories , Austin , TX
Information 512-416-8500
www.silabs.com