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Infineon XENSIV™ Photoacoustic Spectroscopy (PAS) CO2 Sensor

Measure what matters the most

The Infineon XENSIV™ Photoacoustic Spectroscopy (PAS) CO2 Sensor provides superior accuracy level in an exceptionally small form factor making it the ideal solution for indoor air-quality monitoring stations, HVAC systems and IoT applications. To track the environment you are in - for improved health, productivity and overall well-being, the PAS CO2 sensor provides real-time, accurate measurements, while being more affordable and compact, overcoming the challenges of size and performance in existing CO2 sensor solutions.

Infineon's MEMS microphone, which is optimized for low-frequency operation, detects the pressure change generated by CO2 molecules within the sensor cavity. CO2 concentration is then delivered in the form of a direct ppm readout thanks to the integrated microcontroller. Highly accurate CO2 readings are guaranteed since the absorption chamber is acoustically isolated from external noise.

The XENSIV™ PAS CO2 sensor is a real carbon dioxide (CO2) sensor in an unprecedented small form factor. Designed on the basis of the photoacoustic spectroscopy (PAS) concept, the sensor saves more than 75 percent space compared to existing commercial real CO2 sensors. Its direct ppm readings, tape & reel packing, SMD capability and simple design allow for a quicker and easier integration into customers’ systems in low and high-volume applications alike.

Features & Benefits
  • Unprecedented small form factor (14 x 13.8 x 7.5 mm3)
  • Accurate and robust performance at ppm level (±30 ppm ±3% of reading)
  • SMD package delivered in tape and reel
  • Advanced compensation and self-calibration algorithms
  • Customer flexibility thanks to a variety of configuration options and interfaces
  • Space savings in customers’ end products
  • High-quality data and compliance with smart building standards
  • Cost-effective high-volume assembly and easy system integration
  • Plug & play for fast design-to-market
  • Building automation: demand-controlled ventilation, air handler units, air exchangers
  • Home appliances: air purifiers, air conditioners
  • Smart home IoT devices: thermostats, speakers, baby monitors, personal assistants, indoor air quality monitors, smart lighting
  • Agriculture: greenhouses, indoor/ vertical farming
  • City management / CO2 emissions control: outdoor lighting, bus stop stations, advertising billboards
  • In-cabin air quality monitoring


Successful Evaluation of the Sensor

XENSIV™ PAS CO2 Sensor2Go Evaluation Kit

To ensure efficient and quick evaluation, discover the Infineon XENSIVTM PAS CO2 Sensor2Go Evaluation kit. It enables communication to a PC GUI via its micro-USB as a power management unit ensuring stable 12 V for the light source.


Infineon – XENSIV™ PAS CO2 Sensor2Go Evaluation Kit
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The Sensor2Go evaluation kit includes:

  • XENSIV™ PAS CO2 evaluation motherboard
  • XENSIV™ PAS CO2 mini-evaluation board
  • micro-USB cable


XENSIV™ PAS CO2 Mini-Board

The XENSIV™ PAS CO2 mini-board enables easy connection to the application board with a standard 2.54 mm pin header, and without the need to go through a reflow process during the evaluation phase.


Infineon – XENSIV PAS CO2 mini-board
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The Mini-Board comes with the following features:

  • Access to all signals and functions of the product
  • Compatible with a combined PCB layout, supporting reflow assembly for later use
  • Compatible with XENSIV™ PAS CO2 Sensor2Go kit for easy lab evaluation


How does the photoacoustic principle work?

Pulses of light from an infrared source pass through an optical filter tuned specifically to the CO2 absorption wavelength (λ = 4.2 µm). The CO2 molecules inside the measurement chamber absorb the filtered light, causing the molecules to shake and generate a pressure wave with each pulse. This is called the photoacoustic effect. The pressure change is then detected by a MEMS acoustic detector optimized for low frequency operation, and the microcontroller converts the output into a CO2 concentration reading. In order to provide accurate CO2 sensing information, the absorption chamber is acoustically isolated from external noise.

Infineon – XENSIV™ Photoacoustic Spectroscopy (PAS) CO2 Sensor Block Diagram

Block Diagram: Infineon XENSIV™ Photoacoustic Spectroscopy (PAS) CO2 Sensor


Infineon – XENSIV PAS CO2


WATCH: How To Monitor Indoor Air Quality, Featuring Infineon’s CO2 Sensor