MICROCHIPS

A microchip is an electronic device built as a single unit from many miniature components—mainly transistors. It is plugged in to a socket on a printed circuit board to connect it to other components.

WHAT DO MICROCHIPS DO?

Each kind of microchip performs a different task, and is identified by a code number. Some microchips work with analog signals (a microchip with code 741 is an analog amplifier). Others work with digital signals—to act as LOGIC GATES, or to get digital sound from a CD.

HOW ARE MICROCHIPS MADE?

Microchips are made by building up electronic circuits in a tiny wafer (slice) or pure silicon in a complicated layer-by-layer process. The different circuit components are produced by doping (treating) areas of the silicon with different chemicals.

WHAT IS BINARY CODE?

Digital microchips send and receive digital electronic signals in binary code. All information is represented by on/off signals. These signals are processed by the transistors on microchips. When a switch is on, it is the digit 1; when it is off, it is the digit 0. The binary code for the letter “a” on a keyboard is 01100001.

LOGIC GATES

A logic gate is a digital circuit that makes a simple decision. Logic gates include AND, OR, NOT, NOR, and NAND gates. Logic gate circuits can be made with individual transistors, or formed on microchips.

HOW ARE LOGIC GATES USED?

You can link logic gates to make complex decisions, or perform difficult calculations. For example, a washing machine can be designed to start only when a program has been selected AND the door is closed AND the water supply is on.

FIND OUT MORE

Computers
Electronics

Copyright © 2007 Dorling Kindersley