The BS612 is a pyroelectric infrared sensor module that integrates the digital intelligent control circuit and the human body detection sensitive element in the electromagnetic shielding cover. The human body detection sensor couples the sensed human body movement signal to the sensor through a very high impedance differential input circuit.On the digital intelligent integrated circuit chip, the digital intelligent integrated circuit converts the signal into ADC digital signal, there is a timed REL level output when the PIR signal exceeds the selected digital threshold. The OEN enable terminal enables the REL output or automatic control by the light sensor. Sensitivity and time parameters The number is set by a voltage divider resistor. All signal processing is done on-chip.
Features

Digital signal processing
Low voltage, low power consumption, and short warm-up time.
High power rejection ratio, anti-RF interference (mobile phone, WiFi, etc.)
Special built-in second-order Butterworth bandpass filter of an infrared sensor to shield input interference of other frequencies
With sensitivity, timing, light sensor Schmitt REL output
Timing simulation is continuously adjustable
Good stability, effectively suppressing repeated misoperations
The application circuit is simple

Resources
Datasheet