CD4017 is a Decade Counter based on CMOS IC used to as a counter intergrated into counting applications. It is capable of counting from 0-10, thats why it is called decade counter and most common used IC in pulse counting applications. CD4017 is based on Johnson 10 Stage Counter.
The CD4017 is a Johnson decade digital IC capable of outputing 10 digital output, making it sourcing 10 individual output pins. Anytime only one pin is HIGH at one time and we can change it by inputing positing positive voltage at clock pin of the IC. We will discuss this process in later in this article. While functioning only one pin has voltage HIGH or “1” and other remains LOW or “0”. So it is capable of producing lighting effect sequentially with 10 pins one by one, with the speed depends on clock in pulse.
- Pin from 1 to 7 and 9 to 11 are the output pins, output pin used to read HIGH signal. When we apply pulse to the Pin 14 which is a clock pin and rising edge of the pin will start shifting the HIGH voltage to next pin, will discuss later in this article.
- Pin12 is the cascading pin when we need to add more than one CD4017 IC then this pin is used to connect. There is a limit with this method, we can not connect more than 20 IC with this. This is useful when we want to integrate more IC for further processing circuits, Every CD4017IC will enhance and increase the count range of 10. But it is always recommendation, not to connect more than 3 CD4017 in cascading mode.k.
- PIn 13 plays an important role to disable or enable the CD4017IC, normally it is active low. We need to connect it with the negative logic LOW voltage to make it active. If we supply HIGH logic to this pin it will disable the functioning of the processing.
- Pin 14 is a clock input pulse pin, plays very vital role in the IC. This is a clock pin used to receive pulses from the external circuitry. When we apply pulse to this pin then the IC will start counting and from 1 to 10 Pins, The rising edge of the pulse will increase the count and the control will come to the next count pin, it will be HIGH.
- Pin 15: is the reset input pin,used to reset the IC CD4017 from its normaly operation, It should be LOW for its operation, When need to reset the IC then apply High voltage to this pin
- Pin 16 is input voltage and accepts voltage from the range of 3V to 15V for its operations.
- Pin 8 is negative voltage supply, used to connect negative supply to the IC for functioning.