This circuit is from the GLOLAB web page. The document referenced here includes an excellent design as well as an excellent tutorial on PIR devices. You've probably seen these ...

PIR LED Security Light Circuit Schematic Notes The PIR sensor requires an initial stabilization time of about 10 to 60 seconds in order to function properly. During this time, the sensor gets familiar ...

By making the sensor surface-mountable, the device now occupies 30% less in volume versus that required by traditional PIR sensors. Height was also reduced to approximately 60% that of its ...

The passive infrared (PIR) sensor market is experiencing significant growth as demand for efficient motion detection and ...

As an example, [Circuit Valley] has an IKEA Vallhorn motion sensor for a teardown, it’s as you might expect, a passive infrared sensor (PIR) sensor coupled with a Zigbee interface.