Practical Electronics/555

The 555 timer IC is a very versatile and useful component and can be used for many things, from giving clock pulses to switch debouncing and as an output transducer. The basic 555 IC is housed in an 8-pin carrier, and these come in DIL and SOIC formats. They run from 3-15V, and are generally quite hardy devices. The name "555" originated from a design feature, as there are three 5 kilo ohm resistors present in the input voltage divider network of the device.

Pinout
The 555 has 8 pins. The layout of these pins is shown to the right and the function of these pins in given in the table below.