PIR Motion Sensor PaPIRs Design Concept

The integrated amplifier /comparator circuit inside a TO-5 metal can (digital type) prevents interferences caused by electromagnetic fields, such as those generated by cell phones and wireless devices. A special differential circuit design is introduced for the EKMB 6μA type for applications where a high noise resistance is required (up to GHz range).

Thanks to the special design of the small pyroelectric elements, it is possible to use a smaller lens size while keeping the same detection area and distance compared to conventional sensors.

The sensitivity has been significantly improved thanks to a unique slit design of the pyroelectric elements. The separated sensing areas prevent thermal crosstalk between the single sensing elements. Therefore, reliable detection is possible even if the temperature difference between the background (e.g. floor /wall) and the target object (human) is small. (e.g.△T＝４°C)

Improved signal-to-noise ratio thanks to a special I/V circuit which is used for converting a current signal from the pyroelectric element to voltage.
Panasonic PIR motion sensors perform by the feedback capacitor and the operational amplifier, different from the conventional FET-type, thereby decreasing the probability of false alarms due to temperature fluctuation.

A ferroelectric Lithiumtantalate (LiTaO3) single lead-free crystal is used as the pyroelectric element for Panasonic PIR motion sensors. Conventional PIR motion sensors normally use a ceramic base material (e.g. PZT) for the pyroelectric element, which contains lead in many cases.

PaPIRs: High signal-to-noise ratio   Threshold   Analog output diagram Threshold   Conventional types: Low signal-to-noise ratio   Threshold   Analog output diagram Threshold

Reduction of current consumption (1, 2 or 6μA) thanks to the special circuit design technology allows battery life to be extended for battery-driven products.