As a professional manufacturer in the field of gas sensors, Shanxi Tengxing Sensing Technology Co., Ltd. is deeply engaged in the research and development and production of sensor technology. Among them, pyroelectric infrared sensors (PIR) are widely used in security, smart home, automatic lighting and other fields due to their high sensitivity, low power consumption and stability. Today, we will deeply analyze its core structure and working principle to help you better understand this key device.

Core structure of pyroelectric infrared sensor

The structural design of pyroelectric infrared sensor directly affects its detection performance, mainly including the following key components:

Pyroelectric sensitive element

Material: Usually pyroelectric materials such as lithium tantalate (LiTaO₃) and triglycine sulfate (TGS) are used, which can generate charge due to temperature changes.

Features: Sensitive to infrared radiation. When infrared rays emitted by human body or objects irradiate the surface of the element, its temperature change triggers charge displacement and outputs electrical signals.

Infrared filter (window)

Function: Filter out visible light and other interfering wavelengths (such as sunlight and light), and only allow infrared rays of 8-14μm (human infrared characteristic band) to pass through, thereby improving the signal-to-noise ratio.

Field effect tube (FET) impedance converter

Function: Convert the high impedance charge signal generated by the pyroelectric element into a low impedance voltage signal for subsequent circuit processing.

Support structure and packaging

Metal shell/ceramic base: Protect internal components from environmental interference (such as humidity and dust) while optimizing heat conduction.

Fresnel lens (optional): An external lens can focus the infrared radiation to extend the detection range or form a specific sensing area.

Brief description of working principle

    When a moving heat source (such as a human body) enters the sensor detection area, the infrared radiation it emits is focused onto the pyroelectric element through the filter, causing the surface temperature of the element to change and generate charge; the charge is converted by FET and outputs a pulse signal to trigger subsequent control circuits (such as alarm or lighting).

Tensensor technical advantages

High signal-to-noise ratio: optimize the matching of filters and components to reduce false triggering.

Wide voltage adaptation: support 3V-5V power supply, compatible with a variety of circuit designs.

Long life packaging: moisture-proof and dust-proof design, adaptable to harsh environments.

Typical application scenarios

✅ Human body sensing lighting

✅ Smart home automation

✅ Security alarm system

✅ Energy-saving equipment control

GDA223-F Digital Pyroelectric Sensor

    Tensensor continues to innovate pyroelectric infrared sensor technology to provide customers with highly reliable and customized solutions. If you need product selection or technical support, please contact our engineering team!

Email: [email protected]

Tel/WhatsApp: +86 18335818384

Website: www.tensensor.com