Infrared light, commonly referred to as “IR”, is a common, easy-to-use, low power and low-cost media to transmit information. Among the few “wireless” communication choices, IR has the significant advantage of compatibility with hundreds of millions of electronic devices with IR ports (i.e., laptop PCs, PDAs).

This document describes the fundamentals of the infrared physical layer, the IrDA standard and selecting the proper discrete emitter and photodiode components for circuit implementation.