GA412 Pyroelectric Infrared Sensor

Features

* Digital signal processing techniques are used to process pyroelectric signals.

* The differential high-input impedance input of Channel 2 serves as the sensor’s sensitive element input, offering enhanced anti-interference capability.

* Built-in digital bandpass filter effectively eliminates interference from other spurious frequencies.

* All signal processing is performed within a metal housing, providing enhanced resistance to electromagnetic interference.

* The timing can be externally adjusted.

* Low operating voltage, low power consumption, and fast response time.

Application

* Smart security protection against infrared motion intrusions and more

* IoT Infrared Motion Detection

* Automatic lighting control for stairwell lights, indoor lights, corridors, etc.

* Solar-powered automatic sensor light

* Smart home appliance sector, including refrigerators, air conditioners, televisions, and more

* Occupancy detection

Scope of Use

This document is used for digital intelligent pyroelectric infrared sensor output devices.

Sensor output format

Digital TTL output

Product name and product number

Product Name

Smart Digital Pyroelectric Infrared Sensor

Item number

GA412

Appearance and dimensions

Appearance

The surface is smooth, free of scratches, stains, rust, and other such defects.

Appearance and dimensions

TO-5: For detailed dimensions, please refer to the attached drawing.

Electrical Performance Parameters

Larger rated parameters

Any electrical stress exceeding the parameters listed in the table below could potentially damage the device. Operating under these higher-rated conditions may affect the device’s reliability.

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Working conditions ( Ambient temperature 25 Celsius )

Internal block diagram

Output REL trigger mode

When the sensor receives a valid signal—after it has been processed by a digital filter—that exceeds the internal trigger threshold, an internal counting pulse is generated. If the sensor receives another such signal, a second pulse is generated internally. If two pulses are received within 4 seconds, the REL pin will output a high-level signal. If the amplitude of the received signal exceeds the trigger threshold by more than five times, only one pulse is needed to trigger the REL pin to output a high-level signal. The delay time for the REL output starts timing from the moment of the most recent valid pulse.

Delay time adjustment

The voltage applied to the ONTIME pin determines the duration for which the REL output remains activated after the last alarm. If multiple alarm conditions are detected during the output period, the timer will be reset and restarted each time an alarm condition is detected.

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Table of REL Output Duration Corresponding to ONTIME Pin Voltage

Optical Performance Parameters

Window material transmittance spectrum

Spectral characteristics of the filter

External dimensions

Pin definitions

Reference circuit

Precautions

1. A pyroelectric infrared sensor detects changes in infrared energy and outputs a signal accordingly. However, it will also generate a signal in response to changes in infrared energy from non-human sources—for example, small animals, direct sunlight or other intense light sources, or conditions where air conditioners cause rapid temperature fluctuations. If the heat source is stationary or moving at high speed, or if the ambient temperature is close to human body temperature, the infrared signal emitted by the human body may not produce sufficient fluctuations; in such cases, the sensor will not output a signal.

2. By properly installing the sensor’s optical window in conjunction with a Fresnel lens, an ideal detection distance and angle can be achieved. When designing, it is important to select an appropriate lens and avoid exposing the sensor’s metal housing directly to the external flowing air.

3. During use, try to avoid excessive vibration. The optical window must be kept clean and free from friction by hard objects or other debris, as such friction could lead to performance failure or instability.

4. During the sensor soldering process, try to avoid excessively high temperatures and prolonged soldering times. It is recommended to keep the temperature below 290℃ and limit the soldering time to less than 3 seconds.

Packaging and Quantity

Component Packaging Drawing (Unit: mm)

100 sensors per pack / in cardboard box

Outer carton packaging drawing (unit: mm)

Small packaging box: 390*260*145; packaging sensors: 30*100 = 3,000 units.

Large packaging box: 630*440*310. Packaging sensors: 4*30*100 = 12,000 units.