STMicro Launches a Tiny Low-Power Thermal Sensor as an Alternative to the Classic Passive Infrared
Drawing just 10µA and with a 13-foot range, this lensless sensor aims to replace PIRs for presence and activity detection.
STMicroelectronics is hoping to temp engineers away from the tried-and-tested passive infrared (PIR) motion sensor with a new low-power lensless thermal sensor, the STHS34PF80 — offering embedded presence and motion detection capabilities.
"Today’s smart homes, smart buildings, and IoT [Internet of Things] applications need accurate presence detection to improve control of systems such as lighting, heating, security, and safety monitoring for a sustainable future," claims STMicro's Simone Ferri in support of the launch. "Our new STHS34PF80 is an economical, ultra-low-power sensor that lets building automation operate consistently whether detected occupants are moving or not. It’s made using an innovative combination of CMOS chip fabrication, silicon micro-machining, and low-voltage circuit design capabilities."
Designed for use in place of a PIR motion sensor, the STHS34PF80 is the latest in STMicro's growing family of sensor devices with embedded smarts — running presence and motion detection directly on the sensor in order to reduce load on the host processor, or even allow it to enter a low-power sleep mode until woken. The sensor itself boasts a low power draw, too, claimed at 10µA operating current — less, STMicro points out, than an equivalent PIR sensor.
The sensor itself is built using thermal MOSFETs (TMOS), which pick up infrared radiation from nearby warm-blooded creatures — humans, primarily. The company is positioning the part as ideal for alarms and other security systems, smart lighting, and home automation, with promises a lens-free range of four meters (around 13 feet) and an 80 degree field of view (FOV) in a tiny 3.2×2.4mm (around 0.13×0.09") surface-mount package.
In addition to the device itself, STMicro has announced the launch of an evaluation board which connects the sensor to the company's X-NUCLEO-IKS01A3 or STEVAL-MKI109V3 development boards. A ready-to-use library for people and object detection, meanwhile, is available in the X-CUBE-MEMS1 software package.
The evaluation kit is now available to order from STMicro directly, priced at $35; the bare sensor can be ordered for $2.60 per unit in tray quantities of 1,000 units. More information is available on the official product page.