Interface Code Implementation for the MAX9635 Ambient Light Sensor

By: Prashanth Holenarsipur

Abstract: This application note describes the proper use of interrupt output functionality in the MAX9635 ambient light sensor for LCD backlight management in portable devices like smartphones and tablets. The interrupt functionality allows adjustment of light threshold values for multiple illumination zones without the need to poll the light sensor repeatedly. When used properly, this function allows the system to remain in a low-power sleep mode or to dedicate other resources for other user-defined tasks. The interrupt functionality significantly improves energy efficiency, system performance, and the user's experience in different lighting conditions. This article also gives an example of I²C C pseudocode for programming the interrupt.