IC 4017/CD4017 Datasheet | Pinout | 15 example circuits

When we build the 10 LEDs running light for a hobby. Often use CD4017 CMOS-IC.

Why we use it?

The CD4017 is one of the most versatile counters.

Imagine It can count up to 10 and has 10 separate outputs. And will show a single output pin for each count from 0 to 9.

CD4017 Datasheet, pinout

Because this chip contains the counter and the decoder section, too. It is so good.

Do not just look at it.

You should learn by doing many circuits using 4017.


CD4017 CMOS-Decade counter/divider

And also use to build all kinds of the timer, LED sequencers and controllers circuits.

Look at the Figure below is a block diagram of inside IC 4017 / HCF4017 .

This counts with 5 D-type flip-flops.

Decoding and control are by 16 inverters and 15 gates.


Figure 1 block diagram inside CD4017 Pinout

The importance Pins look at the table below.


LM4017 Pinout

See the CD4017 pinout and function of each pin.

CD4017 pinout
CD4017 Photo

Thanks: Photo CD4017 Buy now

1.) Pin 16 is a positive power supply and pin 8 is a ground.

The power supply range of 3 volts to 16 volts. And Maximum power supply voltage does not more than 18 volts.

Power supply pins of CD4017

2.) Pin 13 has Clock enabled pins to controls the clock.
When it is “0” logic, the clock is enabled and the counter advances one count for each clock pulse.

When it is “0” logic, the clock is enabled and the counter advances one count for each clock pulse.

When “1” logic, the clock input is stopped, and the counter does nothing even when a clock pulse arrives.

3.) Pin 14 is the clock triggers one count.

The clock pulse must be “clean”.

If they are “noisy” the counter may advance two or more times during each clock pulse.

The counter will count on the positive-going clock signal.

4.) Pin 15 is the reset pin. Normally, it is “0”.

When made “1”, the counter is reset to “0”.

5.) Pins 1-7 and 9-11 are the decoded output pins.

The active count pin goes high and all others remain low.

In the first LED1 is the first out and is labeled “0” as you will see later when the IC is used as a counter.

Also, In the 10 output are normally LOW and go HIGH in sequence one LED will light at a time.

6.) Pin 12 is Carry output, for the clock input of an additional counter or an external circuit that the count is complete.

How it works

I want to see you improve in Electronics learning, can use CD4017 well. Here is step by step a process that I think simple for you.

Meet basic frequency divider

If we feed a frequency of 10Hz to the input pin 14. Then, it is equally divided between the 10 outputs.

So, the first output or any other outputs will turn ON and OFF once per second.

We see that this chip can divide the frequency by 10. Often people call CD4017 a decade counter/divider.

If you want a real using this function, other frequency dividers. You should read below.

Output Buffer

Each output of a CD4017 has a buffer. It can drive an LED. This buffer gate inside the IC. It does not involve external circuits. And this falling waveform is also internal.

The Cycle on its input indicates it receives a low during quiescent conditions. And, changes to this low state on the falling edge of the waveform.

Each output buffer of CD4017

Control Pins

Look at Figure And learn with me.

Reset-clock inhibit-pin-4017

The counter circuit has 2 other important pins:

  • Reset
  • Clock ENABLE (Clock inhibit)

They are the control pins. So, we must connect them to either high or low. We cannot leave floating them. This applies to the reset & clock inhibit pins.

Reset Pin
First, when the reset pin connects to a low voltage(Vss). This IC will count the full 10 outputs.

Then, we try to feed a voltage above 2/3 VDD( such as If VDD is 9V, it is 6V) Or a pulse of short duration into the reset pin.

It will reset the IC to the first status. It is the output (pin number 3).

And if we keep the reset pin is high, the counter will still at pin 3.

Clock ENABLE pin
Second, when we connect the clock enable (clock inhibit) pin to Low status. The IC will count the full 10 outputs. As shown above.

In contrast, we connect it to a high status. The counter will freeze on or restrain the output in operation.

In short, we often connect pin 13 to ground.

Make stability control pins

Resistor make stability control pins

We should add R1 and R2 the 100K to 1M resistors to keep spikes from entering the control pins.

While at the same time gives the pin a high impedance path to any control voltages.

Even we use R1, R2 is 1 M resistors the two pins will look like connected to VSS or ground. Because no current is flowing. And, so no voltage is across the resistors.

Do N frequency divider

What is more? We back to learn how the CD4017 will divide by 9 or 8 or 6 or 5 or 4 or 3 or 2. See below

Divide-by-9 Circuit

Divide by 9 circuit CD4017

Are you get ideas? See next…

We connect the output number 10 to the reset pin.

This will make the counter count to 9 then reset.

Divide-by-six Circuit

Divide by 6 circuit CD4017

Then, we connect 7th output to the pin 15 (reset).

Also, it will the counter count to 6 then reset.


A divide-by-N. circuit for the CD4017 requires the N + 1 Output to be connected to the reset pin.

This circuit is helpful for add divisions or for a circuit requiring easy alteration.

For standard division, a number of cheaper and better IC’s are available.

Read also, you will get more ideas

Do you love it? Read next…

How to Cascade the 4017 counter

We can cascade two (or more) 4017 counters to produce a counter. See the circuit diagram, we use two 4017.

How to Cascade the 4017 counter

Ideally, it can be a pre-set counter in which the outputs are diode gated to a signaling device such as a lamp or bell.

We arranged the circuit to create a forward reading display and any number of chips. And we can add to increase the range.

Then, the carry-out pin 12 connects to the clock in the next counter. And, the reset and clock inhibit pins must connect to ground (Vss).

The advantage of including the 100K resistors allows a simple push-to-make switch. To control in the circuit for “reset” or “freeze”

Thanks: Photos Buy CD4017 HERE

For example, 15 basic circuits using CD4017

10 LED Flashing using IC-4017

This the circuit diagram of light LED flashing with a show of 10 LED.

By using integrated number circuit CD4017 perform be Decade Counter/Divider with 10 Decoded Outputs.

10 LED flashing using CD4017

Which, it is an integrated digital circuit CMOS. Then, use the 9V power supply.

For a signal input continue the circuit can produce general frequency may use IC NE555 all right.

LED Chaser circuit using 555 and 4017

LED Chaser circuits using IC 4017 + IC 555

If you would like to learn basic digital. But it is difficult and boring.

Let’s try to create an LED chaser circuit. It used in computer games and in many scientific and mathematics applications.

So it is best for a beginner or for kids to learn digital.

Also, my son loves them. Continue Reading

Two way 12 LED running lights using 4017


If you want a new style or beautiful lighting. The project may be good choice of yours. This is a two ways of LED running lighting.

Which it is one of the 4017 project that uses 12 LED lamps, arranged in 2 rows, each row of 6 LEDs. A green one and a red one, alternatively. You can use a different color for this.

Continue Reading To Look at more detail.

0-99 counter using 2x LM4017 IC

When you want the counter circuit from 0 to arrive at 99. I think this circuit may on the same wavelength you certainly.

It uses an LM4017 decade counter/divider as a circuit diagram below.

When we feed a signal clock at 14 pins. It causes the position logic at a pin output. From 0 to 99.

For switch, S1 perform choose RUN or Reset.


Please see the circuit picture will understand increasingly.

Almost forget integrated number this circuit, requires low voltage 3V to 15V power supply. Because it is IC digital CMOS.

10 Key Code Lock Switch Circuit

Key Code Lock Switch Circuit Using IC-4017

Simple Keycode lock switch circuit using IC-4017 digital uses 10 switch bottom to control output by Relay. No microcontroller is so easier and cheaper! Continue Reading

1 Hz Timebase circuit using IC-4017

1 Hz Timebase circuit using IC-4017

When we need a standard digital clock 1 Hz. but we have the input signal is square waveform 10 Hz so need to reduct it lower with digital frequency divider circuit 10 times
I suggest that IC 4017 (Decade Counter / Divider with 10 Decoded)

Bicycle distance meter circuit using 4N26, CD4017

With this circuit, you can measure the distance by using a bicycle wheel.

It includes a few parts, normal electronic circuits. And, has the important parts are reed switch detect a magnetic force to CD4017.

Bicycle distance meter circuit using 4N26,CD4017

It is a Decade counter with 10 decoded outputs IC.

Then connected to Optocoupler 4N26, and display to a frequency counter.

2 Coin toss Game circuits diagram

Coin toss electronics using IC NE555-CD4017

Press Switch-S1 you will see LED blink alternately. When release S1 LED will stop show Coin or Toss.

Automatic Day Indicator Circuit

The Automatically Day indicator circuit

This is the Automatic day indicator circuit, by LED display each day one by one LED.

Which uses the principal of light-activated in a day with sun. To set an LDR-sensor and CD4017 acts as drive LED of 7 pcs for 7 days there.

Electronic dice circuit using CD4017

Electronic dice circuit using CD4017

Which looks like real dice. We use only the press switch being thrown. With 6 LED Display.

10 LED roulette circuits using TC4011-LM4017

The 10 LED roulette circuit using IC-4017 and IC-4011

They use the principles of digital ICs. Create an integrated LED flashing to the rhythm. And then stopped at one of the LEDs.

Enjoy creating a game. And knowledge From digital ICs.

Love Test Game Circuit using 8 LEDs

Love Test Game Circuit using 8 LEDs

555 Sound effect generator circuit

This circuit would be a good starting point to composed music for 1000 tracks.

We will use an IC-555 timer and IC-4017 Decade Counter Divider with 10 Decoded.

Simple sound effect generator circuit using IC-555 and IC-4017

And has the sound effect generator with adjusting tone music with a tempo slow-fast as you want it to VR11.

And VR1-VR10 to adjust the tone according to need more than 1000 tone.

LED Dancing light circuit with Music

The main features are running light by changing the voice of the tiny microphone.

Led light movement the audio signal with LM358- IC 4017

In the circuit, we use 4017 to drive 10 LED display. And, LM358 is a preamplifier and signal converter. With a few general devices.

Besides 4017 on my website. You can also see more.

10 step LEDs charser using ic 4017 only without PCB board

Amazing 4017 IC led chaser

Which is better? Which circuit do you like to build?

Have fun with the IC-4017.

Related Posts


I always try to make Electronics Learning Easy.


  1. Rich Man

    For the 10 LED Flashing Circuit Using IC 4017, there are three connections at the bottom right of the schematic, from right to left numbered 8 and 13. The next one is not numbered. What pin is it connected to?

  2. Richard Lowery

    The connections for the LED’s are shown to start at pin #0. My IC doesn’t have a ‘zero’ pin. The pins start with #1 at the upper left of the 4017, with the first pin being #1, then going down the side to pin #8, and continuing up the other side to pin #16. The connection I question is for D10 and is shown as connection 3. What is pin zero?

  3. Name

    Please replacement 10th output name to pin 11. 
    3 pics have mistake.
    Thank you..

    • Hello Name,
      Thanks for your feedback. You are a great man.
      You are a very observant electronicist. Thanks for the advice.
      I have already fixed it.
      If there are any other suggestions I was very pleased.

      Thanks again,

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