ST STHS34PF80 Sensor: Advanced Detection
On July 31, 2023, STMicroelectronics (ST), a renowned semiconductor company, introduced an advanced human presence and motion detection chip. This cutting-edge chip greatly improves the monitoring performance of security surveillance systems, home automation devices, and IoT devices that rely on passive infrared (PIR) sensing technology.
The new STHS34PF80 sensor from STMicroelectronics stands out from conventional PIR sensors because it can detect not only moving objects but also stationary ones, thanks to its embedded thermistor. Moreover, while traditional PIR sensors use Fresnel lenses to detect movement, ST's innovative detector employs a simpler lensless structure.
Simone Ferri, General Manager of STMicroelectronics' AMS MEMS Division, emphasized the importance of precise human presence detection capabilities in today's smart homes, intelligent buildings, and IoT applications. The STHS34PF80 sensor offers an economical and ultra-low-power solution, ensuring seamless operation of building automation systems even when occupants are stationary, without any disturbances. This product also integrates CMOS chip manufacturing processes, silicon micromachining technology, and low-voltage circuit design in a groundbreaking manner.
The STHS34PF80 sensor comes equipped with intelligent algorithms for human presence and motion detection, making it ideal for various applications such as alarm security systems, home automation, smart lighting, IoT devices, intelligent storage lockers, and smart intercom systems. Its lensless design enables a detection range of up to four meters and an 80° field of view in front of the sensor. With a current consumption of only 10µA, it outperforms traditional PIR sensors in terms of power efficiency. Its compact 3.2mm x 4.2mm x 1.455mm surface-mount package allows for high-speed assembly on automated production lines. Additionally, the sensor exhibits strong resistance to direct light and electromagnetic interference (EMI).
To facilitate the testing and development process of the STHS34PF80, ST offers the STEVAL-MKI231KA sensor evaluation board. Developers can easily integrate this board with the X-NUCLEO-IKS01A3 or STEVAL-MKI109V3 mainboard and configure the infrared sensor using STMicroelectronics' user-friendly Unico-GUI graphical interface software, streamlining the measurement process. The STHS34PF80 driver is available on GitHub. Furthermore, the X-CUBE-MEMS1 software package provides a ready-to-use software library for compensation and presence detection of people or objects. This allows users to quickly set up simple applications, measure using the STHS34PF80, analyze test results, and develop new applications.
The STHS34PF80 leverages STMicroelectronics' mature and reliable Silicon on Insulator (SOI) CMOS technology. It efficiently integrates a thermally sensitive MOSFET (TMOS) transistor and digital readout circuitry on a single chip. TMOS thermistor devices demonstrate high sensitivity to the infrared radiation heating the transistor's gate. The SOI architecture, based on ST's mature MEMS (Micro-Electro-Mechanical Systems) process, simplifies the micromachining process, thermally isolates the TMOS transistor, and ensures precise temperature sensing.
Operating in a sub-threshold mode, the TMOS transistor's power consumption is significantly low, resulting in extended battery life for sensors using the STHS34PF80 and reducing the need for frequent charging or battery replacements. Additionally, the use of standard CMOS manufacturing technology ensures cost-effectiveness and high yields on wafers, while sub-micron transistors reduce the sensor's size. Unlike PIR sensors, where sensitivity may vary with thermal pixel size, the STHS34PF80's integrated digital interface enables direct connectivity to the host without requiring external analog front-end circuits, making it an attractive option for electronic components integration.
