There are two devices currently for IR proximity detection: the Si1102 and the Si1120. The features for each are listed in the table. The key difference is that the Si1120 provides ambient light detection and provides a PWM output directly proportional to the reflected energy. The Si1102 does not include an ALS photodiode and is used as a standalone device to provide simple binary logic detection without ambient light detection. The Si1120 ALS photodiode helps identify the background ambient light characteristics for an improved infrared result. Each of these sensors can be used in a wide variety of applications as shown in the figure.