S918-H Digital Intelligent Pyroelectric Infrared Sensor

Short Description:

 1.Overview S918-H is a pyroelectric infrared sensor that integrates a digital intelligent control circuit and a human detection sensitive element in an electromagnetic shielding cover. The human detection sensitivity element couples the sensed human movement signal to the digital intelligent integrated circuit chip through the very high impedance differential input circuit. The digital intelligent integrated circuit converts the signal into a 15-bit ADC digital signal when the PIR signal ex...


  • FOB Price: US $0.5 - 9,999 / Piece
  • Min.Order Quantity: 100 Piece/Pieces
  • Supply Ability: 10000 Piece/Pieces per Month
  • Port: Shenzhen
  • Payment Terms: L/C,D/A,D/P,T/T
  • Product Detail

    Product Tags

     1.Overview

    S918-H is a pyroelectric infrared sensor that integrates a digital intelligent control circuit and a human detection sensitive element in an electromagnetic shielding cover. The human detection sensitivity element couples the sensed human movement signal to the digital intelligent integrated circuit chip through the very high impedance differential input circuit. The digital intelligent integrated circuit converts the signal into a 15-bit ADC digital signal when the PIR signal exceeds the selected digital valve. When there is a value, there will be a regular REL level output. The OEN enable enables the REL output or automatic control through the light sensor. Sensitivity and time parameters are set by resistors and correspond to corresponding values, and their voltage is converted into a digital threshold with 7-bit resolution. All signal processing is done on the chip.

     

    2.Characteristic
    ①Digital signal processing
    ②Enable power regulation for more energy savings
    ③Two-way differential very high impedance sensor input
    ④A second-order Butterworth band-pass filter with built-in infrared sensors shields input interference from other frequencies
    ⑤High power supply rejection ratio, anti-radio frequency interference
    ⑥Sensitivity, timing, light sensor Schmitt REL output
    ⑦LED sensor dynamic output port
    ⑧Low voltage, low power consumption, instant work after startup
    3.Application
    Ⅰ toy
    Ⅱ IoT sensor
    Ⅲ Digital Frame
    Ⅳ Sensor light
    Ⅴ TV, fridge, air conditioning
    Ⅵ Web video camera
    Ⅶ USB alarm
    Ⅷ PIR motion detection
    Ⅸ Intrusion detection
    Ⅹ Occupancy detection
    Ⅺ Interior lights, corridors, buildings, private alarms
    Ⅻ LAN Monitor
    ⅰ Car theft
    4. Performance parameters
    ①Maximum rated value
    Any electrical stress exceeding the parameters in the table below may cause permanent damage to the device. Working under these maximum rated conditions may affect the reliability of the device.

    Characteristics Symbol Min.Value Max.Value Unit Remarks
    Supply Voltage VDD -0.3 3.6 V  
    Working Temperature TST -20 85  
    Current into any pin Into -100 100 mA  
    Storage Temperature TST -40 125  

    ②Working conditions (T=25°C, VDD=3V, unless otherwise specified)

    Characteristics Symbol Min Type Max Unit Remarks
    Supply Voltage VDD 2.7 3 3.3 V  
    Working Current IDD 12 15 20  μA  
    Sensitivity Threshold Value Vsens   120   μV Non-adjustable
    Output REL
    Output Low Current IOL 10 120   mA VOL<1V
    Output High Current IOH     -10 mA VOH>(VDD-1V)
    REL Low Level OutputBlockade Time TOL   2.3   s Non-adjustable
    REL High Level OutputDelay Time TOH   2.3   s  
    Oscillator & Filter
    Low pass filter cut-off       7 hz  
    High pass filter cut-off
    frequency
          0.44 Hz  
    Oscillator frequency onChip FCLK     64 kHz  

    Interior Block Diagram

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    3.Internal schematic

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    4. output trigger mode

    When the pyroelectric infrared signal received by the probe exceeds the trigger threshold inside the probe, a count pulse will be generated internally. When the probe receives this signal again, it will think that it has received the second pulse. Once it receives 2 pulses within 4 seconds, the probe will generate an alarm signal and the REL pin will trigger high. . In addition, as long as the amplitude of the received signal exceeds more than 5 times the trigger threshold, only one pulse is needed to trigger the REL output. The following figure shows an example of a trigger logic diagram. For multiple triggers, the output REL is held from the last valid pulse.

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    5. Extended time ONTIME

    The voltage applied at the ONTIME terminal determines the delay time for the REL to maintain the high output signal after the sensor is triggered. Each time the trigger signal is received, the delay time starts counting again, due to the dispersion of the internal oscillator frequency, the delay time. There will be a certain range of error.

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    6. Sensitivity setting

    The voltage at the SENS input sets the sensitivity threshold, which is used to detect the strength of the PIR signal at the PIRIN and NPIRIN inputs. When grounded, it is the minimum voltage threshold and the sensitivity is the highest. Any voltage exceeding VDD/2 will select the maximum threshold, which is the lowest sensitive setting for PIR signal detection, that is, the sensing distance may be minimum. It should be pointed out that the infrared sensor sensing distance and

    SENS input voltage is not a linear relationship, its distance and the sensor’s own signal to noise ratio, Fresnel lens imaging object distance, moving body’s background temperature, ambient temperature, environmental humidity, electromagnetic interference and other factors form a complex and multiple relationship, that is, can not The output result is judged by a single index, and the actual debugging results shall prevail. The lower the SENS pin voltage is, the higher the sensitivity is, and the farther the sensing distance is. The S918-H has a total of 32 sensing distances, and the nearest sensing distance can reach centimeters. In actual use, the sensitivity can be adjusted by using a resistor divider.

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    5.Transmission spectrum of window material

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    Probe angle

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    6.Dimensions

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    7.Typical application circuit

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    Note: This circuit is a reference circuit for the S918-H digital intelligent pyroelectric infrared sensor.

     8.Precautions

    ❶ S918-H is a pyroelectric infrared sensor that detects infrared changes. Detection of a heat source other than the human body or a change in the temperature and movement of the heat source may not be possible. Need to pay attention to the following general matters. Please be sure to check the performance and reliability with the actual usage status.

    1) When detecting heat sources other than the human body

    (1) When a small animal enters the detection range

    (2) Far-infrared direct-irradiation sensors such as sunlight, car headlights, and incandescent lamps

    (3) When the temperature in the detection range changes drastically due to the warm air of the cold-greenhouse equipment, cold air, and water vapor of the humidifier, etc.

    2) When it is difficult to detect the heat source

    (1) When there is a material such as glass or acrylic that is difficult to transmit far-infrared rays between the sensor and the detection object

    (2) The heat source in the detection range is hardly actuated or moves at a high speed.

    ❷When the inspection area is enlarged

    When the ambient temperature and the human body temperature are relatively large (approximately 20°C or more), even in the specified detection range

    In addition, there are sometimes broad detection areas.

    ❸About other uses

    1) If there is a stain on the window, it will affect the detection performance, so please pay attention.

    2) The lens is made of soft material (polyethylene). If a load or impact is applied to the lens, it will cause malfunction and deterioration of performance due to deformation and damage. Therefore, avoid the above situation.

    3) Damage may be caused when static electricity of ±200V or more is applied. Therefore, pay close attention to the operation and avoid touching the terminals with your hands.

    4) In the case of soldering of the wire, solder the soldering iron to a temperature of 350°C or lower within 3 seconds. Soldering through solder baths may cause deterioration of performance, so please avoid them.

    5) Please avoid cleaning the sensor. Otherwise, the cleaning solution intrudes into the lens and may cause deterioration of performance.


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