Würth Elektronik WSEN-HIDS MEMS humidity sensor capacitor

Würth Elektronik has launched a compact digital humidity sensor in the WSEN-HIDS series. The MEMS (micro-electro-mechanical system) sensor is designed to conduct measurements within a range of ±1.8% RH in the 20–80% relative humidity range. The DFN (Dual Flat No Leads) package for SMT assembly measures 1.5 x 1.5 x 0.5 mm. The sensor works with a current of 0.4 µA and can be operated with a power supply between 1.08 and 3.6 V. The sensor is suitable for distributed IoT sensor networks, such as those in smart farming applications.

The humidity sensor uses a dielectric polymer that interacts with water molecules to adjust the permeability of the capacitor structure depending on the relative humidity of the surroundings. A temperature sensor is also included. Using the integrated analog-digital converter, the momentary temperature as well as the humidity information can be transmitted as 16-bit measurement data directly to conventional microcontrollers via an I²C interface. The heater (also included) with three selectable heating levels can be switched on as required, to enable the sensor to work under demanding ambient conditions without falsifying measurements due to condensation.

The humidity sensor is suitable for a range of applications, from air-conditioning equipment to data loggers in the food industry, to smart buildings, vertical farming and other applications that require environmental control. To support rapid prototyping, the sensor is part of the FeatherWing sensor and the IoT Development Kit from Würth Elektronik.