The Si1102 is a high-performance (0–50 cm) active proximity detector.
Because it operates on an absolute reflectance threshold principle, it avoids
the ambiguity of motion-based proximity systems.
The Si1102 consists of a patented, high-EMI immunity, differential photodiode
and a signal-processing IC with LED driver and high-gain optical receiver.
Proximity detection is based on measurements of reflected light from a
strobed, optically-isolated LED. The standard package for the Si1102 is an 8-
pin ODFN.