The 555 timer IC is an integrated circuit which is used in variety of timer, pulse generations and oscillators applications. The IC 555 timer got its name by three 5kΩ resistor in series used in the internal circuit of the IC. IC 555 is one of the most widely used IC in electronics for its strong and stable properties. The 555 IC can be used to provide time delays as an oscillator and as a flip flop elements. The 555 timer IC comes as 8 pin dual in package (DIP) device. It works as square wave form generator with duty cycle varying from 50% to 100%, oscillator and can also provide time delay in circuits. There are a lot of applications of this IC, mostly used as vibrators like, astable multivibrator, monostable multivibrator, and bistable multivibrator. It is basically a monolithic timing circuit that produces accurate and highly stable time delays or oscillation. When compared to the applications of an op-amp in the same areas, the 555 IC is also equally reliable and is cheap in cost.