The CD4017 is the one of the most popular 16 pin CMOS Decade Counter (Divided by 10 Counter). It takes clock signal from the clock input and turns on the 10 output in sequence, each time when it receives clock input pulses. It is a 5 Stage Divide by 10 Johnson Counter with 10 Decoded outputs. It has a wide supply voltage range from 3V to 15V and is compatible with TTL. It has a medium speed of operation, typically 5Mhz. A popular IC, CD4017 is extremely useful in various projects like Light Chaser, Matrix Die. It is also useful in many applications like Binary counter/decoder, frequency division, divide by N counting, industrial electronics, remote metering, automotive, medical electronics, instrumentation and alarm systems, etc.