Digital infrared sensor p926 series
Product model: p906b / p926s / p926m / p926b
Product No.: p906b / p926s / p926m / p926b
Product features: adjustable sensitivity, working illumination, delay time, output digital signal
Application: smart home, network camera, wireless communication induction products
Product Description: Tel: 021 65928117
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The digital intelligent pyroelectric sensor p906b uses a special analog-to-digital hybrid processing integrated circuit as a built-in processing chip. The integrated circuit combines the complete functions required by a single passive infrared pyroelectric moving detector.
The input with high input impedance is used to access the pyroelectric sensitive element. The pyroelectric signal is converted into a 16 bit digital signal and further processed by digital band-pass filtering. Then the moving detection signal is obtained by comparing with the adjustable threshold. The moving detection signal is output from a push-pull rel output. A digital input terminal allows rel output or forbids rel output In order to convert the illuminance control terminal, the sensitivity and delay time can be set with DC voltage at the corresponding input terminal. The voltage at the sensitivity setting terminal is converted into a digital value with 7-bit resolution, and the voltage at the delay time setting terminal is converted into a digital value with 4-bit resolution, which is divided into 16 delay time options. All the signal processing is done on the chip.
Product introduction product parameters
characteristic:
1. The pyroelectric signal is processed by digital signal processing technology.
2. Two channel differential high input impedance input is used as sensor sensitive element input.
3. A 16 bit high precision AD converter is used to convert the voltage signal generated by the sensitive element into digital signal.
4. A second-order Butterworth band-pass filter is used to filter the digital signal output from AD converter, which can effectively filter the low-frequency and high-frequency noise caused by various reasons.
5. Because the signal processing is completed in the shielded tube shell, it has a stronger ability to resist RF interference.
6. The sensitivity threshold and timing time can be adjusted by external voltage divider.
7. The input terminal of illuminance sensor can control the sensor to work when the ambient illumination is lower than the set illuminance.
8. Low voltage, low power consumption.
Internal schematic diagram:
Schematic circuit diagram:
Trigger event processing mode:
When the infrared signal received by the sensor exceeds the internal trigger threshold, a count pulse will be generated. When the signal is received again, it will be considered that it has received the second pulse. Once two pulses are received within 4 seconds, the rel pin of the sensor will output a high level to indicate that there is a signal. In addition, as long as the received signal amplitude is more than 5 times of the trigger threshold, only one pulse is needed to trigger the rel output high level. If the trigger signal is received continuously, the holding time of rel high level is delayed from the last effective trigger to the delay time determined by ontime terminal.
Sensitivity / threshold:
Relationship between voltage and internal threshold of sens
The voltage applied at the end of sens determines the internal threshold. If the sens is connected to zero and reaches the maximum sensitivity, the internal threshold value is 49uv. If the voltage applied by sens is greater than VDD / 4, the maximum internal threshold value is 462uv.
Characteristics of oen illuminance control enabling terminal:
Hysteresis level of oen pin
Delay time ontime:
The voltage applied on the ontime terminal determines the delay time of rel to maintain high-level output signal after the sensor is triggered. Each time the trigger signal is received, the delay time is calculated again. Due to the dispersion of internal oscillator frequency, the delay time will have a certain error range |
