IR sensor detects up to four meters

Developed as an alternative to passive infrared (PIR) sensors, STMicroelectronics has launched its ultra-low-power STHS34PF80 IR sensor for human-presence and motion detection in alarm and security systems, home-automation equipment and IoT devices. They can detect the presence of a human up to four meters without an optical lens.

STHS34PF80 IR sensor (Source: STMicroelectronics)

The STHS34PF80 embeds a smart algorithm for presence and motion detection, and its lens-free range of four meters and 80° field of view cover a large area in front of the sensor.

The STHS34PF80 sensor contains micromachined “thermal transistors that can detect stationary objects, unlike conventional PIR detectors that require the detected object to be moving to produce a measurable response from the sensor,” ST said. In addition, the novel detector enables simpler and lens-free construction, compared to PIRs that need a Fresnel lens to sense moving objects, added the company.

The new IR sensor features an operating current of 10 µA, offering lower power consumption than a conventional PIR. It offers high resistance to unwanted effects of direct lighting and high immunity to electromagnetic interference (EMI).

The STHS34PF80, housed in a 3.2 × 4.2 × 1.455-mm surface-mount 10-lead LGA package, is priced from $2.60 for orders of 1,000 pieces.

An evaluation kit, the STEVAL-MKI231KA, also is available, along with the X-NUCLEO-IKS01A3 or the STEVAL-MKI109V3 boards, which allow developers to use ST’s Unico-GUI graphical interface to configure the IR sensor and take measurements in a simplified workflow. Drivers for the STHS34PF80 are available on GitHub and a ready-to-use library for compensating and detecting presence of people or objects is available in the X-CUBE-MEMS1 software package.