These are particulate matters with an ambient air diameter of 2.5 microns or less. They may suspend in the air for quite some time. The more of them appear in the air the worse the air pollution is. Comparing with coarser atmospheric particles, PM2.5 particles feature small size, large area, and strong activity as well as tend to attach toxic and harmful substances (including sulfates, nitrates, black carbon heavy metals, and microorganisms). Thanks to their long time floating in the atmosphere and long travel distance, they can go deep in the lungs and cardiovascular system and result in more severe damage to human health and atmospheric environmental quality. The annual average limit for PM2.5 set by WHO Guidelines is 10ug/m3.

PM2.5 module private market segments according to light source:
• Infrared dust sensor — for PM2.5 qualification test
• Laser dust sensor — for PM2.5 qualitative and quantitative test

PM2.5 module application：
• Air purifier, car air purifier, air conditioner, fresh air equipment, air quality monitoring, environmental monitoring, handheld air quality testing equipment, etc.

Nuvoton PM2.5 module solution：
• PM2.5 infrared module: main control by N76E003 MCU (1T enhanced 8051 18 KB Flash, Internal 12-bit ADC)

• • Infrared turbidity detection method：Featuring infrared LED light source, this device obtains hot air flow by thermal resistors at air inlet and outlet and output high level in PWM signal when there are particles passing through. Particles >1um: rough grading indicator. Applicable to mining site dust detection

• • Main control MCU: N76E003
    • 1T enhanced 8051 Flash MCU
    • 18 KB Flash ROM, 1 KB Data RAM
    • Internal 12-bit ADC
    • Built-in high-precision 16 MHz ±1% RC oscillator; room temperature tolerance: ±1%; full temperature full voltage tolerance: ±2%
    • Wide voltage working range: 2.4V ~ 5.5V; industrial grade working temperature: -40~105 °C
    • Excellent ESD & EFT immunity: EFT/4.4KV & ESD/HBM up to 7KV
    • Available package: TSSOP20/QFN20 (3mm x 3mm)

• PM2.5 laser module illustration：Laser scattering particle diameter detection

• • In air path formed by stable airflow system (fan or blower) the optical sensors measure data of particles including tangential and normal moving speed, diameter, and intensity of light reflection; use the last two items to determine dimension of passing particles. Meanwhile, calculate total particle quality and concentration based on number of particles passing through in unit time. Featuring multiple digital interface; particle size >0.3um, display readings. Suitable for home, car, handheld and other air detectors and purifiers

• • Main control MCU: M031
    • Arm® Cortex®-M0 48 MHz
    • 16 ~ 128 KB Flash ROM, 2 ~ 16 KB Data RAM
    • Internal 12-bit ADC, up to 2 Msps and 5 PDMA channel
    • 512 Byte SPROM for easy project management and encryption
    • Built-in high-precision RC 48 MHz oscillator; full temperature full voltage tolerance: ±2%
    • Voltage working range: 1.8V ~ 3.6V (with 5V support interface); industrial grade working temperature: -40~105 °C
    • ESD & EFT immunity: EFT/4.4 kV & ESD/HBM up to 7kV
    • Available package：TSSOP20/28, QFN33, LQFP48/64