Vishay's VCNT2020 is a reflective sensor in a miniature SMD package. It has a compact construction where the emitter and detector are arranged in the same plane. The current output of the sensor is triggered when the emitted infrared light reflects off a nearby object. The operating infrared wavelength is 940 nm. The detector consists of a silicon phototransistor. The sensor has a built-in daylight blocking filter, which greatly suppresses disturbing ambient light and thereby increases signal to noise ratio.