Integrated circuits are miniaturized electronic devices in which a number of active and passive circuit elements are located on or within a continuous body of material to perform the function of a complete circuit. Integrated circuits have a distinctive physical circuit layout, which is first produced in the form of a large-scale drawing and later reduced and reproduced in a solid medium by high-precision electrochemical processes. The term integrated circuit is often used interchangeably with such terms as microchip, silicon chip, semiconductor chip, and microelectronic device.

Overview

• ICs, often called chips, come in several shapes and sizes.
• Most common are 8-, 14-, or 16-pin dual in-line (dil) chips.
• ICs can be soldered directly into printed circuit boards, or may plug into sockets which have already been soldered into the board.
• When soldering, ensure that the IC (or the socket) is the correct way round and that no pins have been bent underneath the body.
• When fitting new ICs it is often necessary to bend the pins in slightly, in order to fit it into the board (or socket).
• Some ICs are damaged by the static electricity that most people carry on their bodies. They should be stored in conductive foam or wrapped in tin foil. When handling them, discharge yourself periodically by touching some metalwork which is earthed, such as a radiator.

FIGURE 3.25   Parts of a 16-pin chip.

Pin Numbering on a Typical IC

The value of the output voltage from simple power supplies is often not accurate enough for some electronic circuits.

The power supply voltage can also vary due to changes in the main supply, or variations in the current taken by the load.