Product brief

XENSIV™ PAS CO2 Sensor
Measure what matters
Infineon has leveraged its state-of-the-art capabilities in sensors and MEMS to develop adisruptive carbon dioxide (CO2) sensor. Measuring CO2, a key indicator of indoor air quality, allows us to optimize what really matters: health, comfort, and energy efficiency.
By leveraging photoacoustic spectroscopy (PAS), XENSIV™ PAS CO2 overcomes the size,performance and assembly challenges of existing CO2 sensor solutions. The sensor comesin an exceptionally miniaturized module (14 x 13.8 x 7.5 mm3) that is four times smaller
and three times lighter than its NDIR counterparts. This enables more than 75 percent
space-saving in customer systems. In addition to its compact design, XENSIV™ PAS CO2
delivers high data quality thanks to its superior accuracy (±30 ppm ±3% of reading). This
makes XENSIV™ PAS CO2 the smallest real CO2 sensor in the world that achieves this levelof accuracy.
All major components of XENSIV™ PAS CO2 are developed in-house according toInfineon’s high-quality standards. This includes a dedicated microcontroller, which runs
advanced compensation algorithms to deliver direct and reliable ppm readouts of real
CO2 levels. The available configuration options make the sensor one of the most versatileplug-and-play CO2 sensors on the market. These options include: dedicated ABOC
(Automatic Baseline Offset Calibration), pressure compensation, signal alarm, sample
rate and early measurement notification, which are mainly useful for power consumption
management. The SMD package, delivered in tape and reel, facilitates ease of assembly,
even in high-speed, high-volume manufacturing.
This ease of integration makes XENSIV™ PAS CO2 the right fit for a variety of applications
in building automation, smart home and air quality monitoring. In HVAC (heating, ventilation and air conditioning) systems, the sensor ensures that optimal levels of indoor air
quality are achieved. Furthermore, by facilitating DCV (demand-controlled ventilation),
CO2 sensing leads to an increase in the energy efficiency of these systems as well as significant savings on energy bills. With its small footprint, XENSIV™ PAS CO2 is also ideal for
smart home appliances and IoT devices such as air purifiers, thermostats, smart lighting
systems, air quality monitors, and smart speakers.
A complete suite of boards (Sensor2Go Kit, Mini Evaluation Board, Arduino-based
Shield2Go, Adafruit-based Wing Board), libraries and application notes will be available tosupport customers in accelerating their design-to-market.

www.infineon.com/CO2

Key features...

› Small form factor (14 x 13.8 x 7.5 mm )› High accuracy (±30 ppm ±3% of3reading) and robust performance› SMD package delivered in tape and reel
› Advanced compensation andself-calibration algorithms› Three interface options: UART, I2C, PWM› Various configuration options... result in key benefits› Space savings in customers’ endproducts› High data quality› Smooth high-volume assembly› Plug-and-play solution› Customer flexibility thanks to variety
of interface & configuration options

Key applications› HVAC (heating, ventilation and airconditioning) systems› Smart home & building appliances
like air purifiers and IoT devices› Air quality monitors

Product brief

Photoacoustic principle: How does it work?
Pulses of light from an infrared source pass through an opticalfilter tuned specifically to the CO2 absorption wavelength (λ = 4.2µm). The CO2 molecules inside the measurement chamber absorb
the filtered light, causing the molecules to shake and generate apressure wave with each pulse. This is called the photoacoustic effect. The sound is then detected by an 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 isacoustically isolated from external noise.

Block diagram
The XENSIV™ PAS CO2 sensor module PCB integrates a PAS
transducer, a microcontroller, and a MOSFET. The PAS transducer
includes a proprietary infrared emitter with blackbody radiation
which is periodically chopped by the MOSFET, a narrow-band
optical filter tuned to the CO2 wavelength and Infineon’s MEMS
microphone, which acts as a pressure sensor and is optimized for
low frequency operation.

XENSIV™ PAS CO2 measurement cell
Microphone

MEMS IRemitter

Gas inlet

VDD3.3

VDD12RxPWM

SCLPSEL
INTTx/SDAPWM_DIS

Microcontroller
and memory

Light source
driverGND

Powermeasurement
circuit

Pin configuration
PinSymbol

Type

Description

1

VDD3.3

Power supply (3.3 V)

3.3 V digital power supply

2

RxInput

UART receiver pin

3

SCL

Input/Output

I2C clock pin (3.3 V domain)

4

Tx/SDA

Input/Output

UART transmitter pin (3.3 V domain)/
I2C data pin (3.3 V domain)

5

PWM_DISInput

PWM disable input pin (3.3 V domain)

6

GND

GroundGround7

INTOutput

Interrupt output pin (3.3 V domain)

8

PSEL

InputCommunication interface
select input pin (3.3 V domain)

9PWM

OutputPWM output pin (3.3 V domain)

10VDD12Power supply (12 V)

12 V power supply for the IR emitter

www.infineon.com
Published byInfineon Technologies AG
Am Campeon 1-15, 85579 Neubiberg
Germany© 2023 Infineon Technologies AGAll rights reserved.
Document number: B132-I0858-V5-7600-EU-EC-P
Date: 01 / 2023

VDD12PWM
PSEL
INTGND

10192

8

3746

5

Please note!
This Document is for information purposes only and any
information given herein shall in no event be regarded as awarranty, guarantee or description of any functionality,conditions and/or quality of our products or any suitability for aparticular purpose. With regard to the technical specifications ofour products, we kindly ask you to refer to the relevant productdata sheets provided by us. Our customers and their technicaldepartments are required to evaluate the suitability of ourproducts for the intended application.
We reserve the right to change this document and/or theinformation given herein at any time.
Additional information
For further information on technologies, our products, theapplication of our products, delivery terms and conditions
and/or prices, please contact your nearest Infineon Technologies
office (www.infineon.com).

VDD3.3Rx
SCL
Tx/SDAPWM_DIS

Warnings
Due to technical requirements, our products may containdangerous substances. For information on the types in question,please contact your nearest Infineon Technologies office.
Except as otherwise explicitly approved by us in a written
document signed by authorized representatives of Infineon
Technologies, our products may not be used in any life-­
endangering applications, including but not limited to medical,nuclear, military, life-critical or any other applications where afailure of the product or any consequences of the use thereof
can result in personal injury.