The new XENSIV™ PAS CO2 5V sensor for higher energy efficiency and improved air quality in buildings

In order to further drive decarbonization, improving the energy efficiency of buildings is crucial, as they contribute significantly to global energy consumption and carbon emissions.

Innovative solutions are needed to optimize energy consumption while ensuring a healthy indoor environment. Infineon Technologies AG is addressing this need with the introduction of the new XENSIV™ PAS CO2 5V sensor. It is based on the Photoacoustic Spectroscopy (PAS) technology and improves energy efficiency by adapting ventilation to actual occupancy, thereby reducing the carbon footprint of buildings. This makes the device suitable for applications such as heating, ventilation, and air conditioning (HVAC) systems as well as room controller and thermostat units in commercial and residential buildings. It can also be used for IoT and consumer devices such as smart lighting, air purifiers, conferencing systems, and smart speakers, as well as emerging applications such as smart horticulture and smart refrigerators.

“Environmental sensing is an important pillar of Infineon's sensor portfolio,” said Andreas Kopetz, VP Ambient Sensing at Infineon. “CO2 sensors play an increasingly important role in smart homes and buildings by continuously monitoring indoor air quality and adjusting ventilation systems accordingly. Our XENSIV PAS CO2 5V is a sensor solution that ensures a healthier living environment for occupants and enables significant energy savings for greater sustainability.”

The XENSIV PAS CO2 5V provides accurate air quality data in real time. Its miniaturized form factor of 14x13.8x7.5 mm³ is identical to the size of the XENSIV PAS CO2 12V sensor and allows seamless integration into a wide range of applications. This makes it easy to adopt dual designs or maintain the same design strategy for both product variants. Compared to the 12V sensor, the 5V version comes with a 5V power supply which further simplifies installation. Moreover, it offers a significantly faster response time of 55 seconds, down from 90 seconds (12 V). This improvement enhances efficiency across various applications, allowing for quicker data acquisition and more responsive performance in dynamic environments. The sensor's design is dust-proof in accordance with ISO 20653:2013-02, which extends the lifetime of the device in dusty environments and minimizes maintenance requirements. In addition, the UART, I²C and PWM interfaces enable seamless integration with microcontrollers and other digital systems, simplifying the design and development process. Ultimately, with its robust performance, the sensor meets the performance criteria of the internationally recognized WELL™ Green Building Standard, enhancing both environmental sustainability and property value.

All major components of the XENSIV PAS CO2 5V sensor are developed in-house according to Infineon’s high-quality standards. Among others, this includes a dedicated microcontroller that runs advanced compensation algorithms to provide direct and reliable ppm readouts of real CO2 levels. The available configuration options make the sensor one of the most versatile plug-and-play CO2 sensors on the market. They include a dedicated ABOC (Automatic Baseline Offset Calibration), pressure compensation, signal alarm, sample rate and early measurement notification, which are especially useful for power consumption management. The SMD package, delivered in tape and reel, allows for easy assembly, even in high-speed, high-volume manufacturing.

The Photoacoustic Spectroscopy (PAS) Principle

The PAS principle works as follows. 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 highly sensitive MEMS acoustic detector detects the pressure change generated by CO₂ molecules within the sensor cavity, and the microcontroller converts the output into a CO₂ concentration reading. In order to achieve a ppm reading as accurate as possible, the acoustic detector is optimized for low frequency operation, and the absorption chamber is acoustically isolated from external noise.

Further information is available at www.infineon.com/co2.

www.infineon.com