See integrated circuit; see chip. An integrated circuit (IC) is a complete, very compact circuit made up from tiny resistors, diodes, transistors and capacitors. Each IC can contain hundreds, thousands or even millions of these components, and the circuits themselves are very complicated. However, we do not need to know the exact details, just what the IC needs as inputs and what we can expect as outputs. If you look in an electronics catalogue, you will usually only be told what voltage the IC was designed for and how each pin of the IC must be connected if it is to work properly.