Analogue integrated circuits
Electronics guide > Analogue integrated circuits

Well, the last chapter was pretty well jam-packed with information about transistors. If you remember, we saw that transistors are very important electronic components. They may be used in one of only two ways: in digital circuits, or in analogue circuits although many, many types of digital and analogue circuits exist.

In terms of importance, transistors are the tops. Theyre far more important than, say, resistors or capacitors, although in most circuits they rely on the other components to help them perform the desired functions. Theyre the first electronic components weve come across which are active: they actually control the flow of electrons through themselves, to perform their function resistors and capacitors havent got this facility, they are passive and current merely flows or doesnt flow through them.

Transistors, being active, can control current so that they can be turned into amplifiers or switches depending on the circuit. Theres nothing magical about this, mind you, were not gaining something for nothing! In order that, say, a transistor can amplify a small signal into a large one, energy has to be added in the form of electricity from a power supply. The transistor merely controls the energy available from this power supply, creating the amplification effect.

Theyre important for another reason, however. They are small! They can be made by mass-production techniques, almost as small as you can imagine, and certainly many times smaller than you could see with your bare eyes. This in itself is no big deal imagine trying to solder a transistor into a circuit which was so small you couldnt even see it! Transistors of the types weve seen so far are purposefully made as large as they are, just so we can handle them.

<< Using transistors