ABSTRACT
The 555 timer is one of the most versatile integrated circuit chips ever produced. Not only is it a neat mixture of analogue and digital circuitry, but its applications are virtually limitless in the world of timing and digital pulse generation. The device also makes an excellent case study for newcomers to electronics because it combines a number of important concepts and techniques. The standard 555 timer is housed in an eight-pin dual-in-line (DIL) package and operates from supply rail voltages of between 4.5 V and 15 V. This, of course, encompasses the normal range for transistor transistor logic (TTL) devices and thus the device is ideally suited for use with TTL circuitry. This device is a complementary metal oxide semiconductor (CMOS) version of the 555 timer that is both pin and function compatible with its standard counterpart. By virtue of its CMOS technology the device operates over a somewhat wider range of supply voltages and consumes minimal operating current.
