Hello,
The IR channel like all the other one are photodiodes (so light receptor). They do not emit any light.
The sensor is measuring with the light counts received and it is dependent on light intensity, light spectrum, light frequency, etc.
Basically on IR channel the sensor will return the quantity of the IR light received (from 750nm to 1000nm).
Into the driver, Lux are computed based on a CCT correlation matrix. It has been computed with data from Red, Green, Blue only because, they were no major improvement by adding IR channel into CCT and Lux matrix computation.
Now the driver is able to support up to 3x14 matrix, so it is possible to generate a 3x4 matrix using IR channel as 4th channel.
The CCT Application note available on st.com helps the customer to generate a new CCT matrix.
