Single-chip relative humidity sensor

Traditional approaches to RH sensing use discrete resistive and capacitive sensors, hybrids and multi-chip modules (MCMs). These legacy approaches suffer from high bill of materials (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. The entire BOM for the Si7005 RH sensor solution is just two bypass capacitors versus the dozens of components often required to implement the same functionality with a discrete solution. The Si7005 device integrates sensing elements, an analog-to-digital converter (ADC), signal processing, non-volatile memory for calibration data and an I2C interface in a monolithic CMOS IC. This high level of single-chip integration makes the sensor rugged and reliable, reduces cost and development time, and simplifies board design. "The Si7005 humidity sensor offers an unmatched combination of ease-of-use, reliability, small size, low power and compatibility with standard manufacturing flows," said Mark Thompson, vice president and general manager of Silicon Labs' Access, Power and Sensor products. "The Si7005 is the only single-chip digital humidity/temperature sensor available from a diversified semiconductor supplier. Silicon Labs offers a broad portfolio of complementary mixed-signal IC products, from low-power microcontrollers to wireless transceivers, to enable comprehensive solutions for wireless sensor nodes and other applications for the Internet of Things." Pricing and Availability Volume production quantities of Silicon Labs' Si7005 humidity and temperature sensor are available now in a 4 mm x 4 mm QFN package. Product pricing for the Si7005 sensor in 10,000-unit quantities begins at $3.64 (USD). The Si7005USB-DONGLE USB-based evaluation board, priced at $49, simplifies Si7005 sensor evaluation. The Si7005-EVB daughter card, priced at $29, includes a flex-cable that enables developers to evaluate the Si7005 in a temperature or humidity chamber. The Si7005EVB-UDP plug-in card for Silicon Labs' Unified Development Platform is priced at $49. The Si7005EVB-UDP-F960 development kit, priced at $149, combines an ultra-low-power C8051F960 MCU development kit with a UDP daughter card into a portable demonstration platform (no PC required) that includes data logger demonstration code. Software drivers are available for Linux and Android platforms. (All board prices are in USD MSRP.)