There are two types of light sensor chips: phototransistors and photodiodes. Photodiodes are solid-state light detectors with a radiation-sensitive. A light sensing sensor (also called a light sensor, photodetector, or ambient light sensor—ALS) converts light into an electrical signal. In practice it is built in two ways: a discrete analog chain or an all-in-one sensor IC. TI's optical light sensors with integrated photo sensor and passive filters offer excellent spectral matching, low power, and configurable conversion times.