CD4017BE CMOS Decade Counter IC

Prototyping and Engineering Tips from Robogears

• The "Floating" Input Trap: CRITICAL: CMOS inputs are extremely sensitive. Never leave the Reset (Pin 15) or Clock Inhibit (Pin 13) pins floating. If they are not being used, tie them to Ground (GND). A floating Reset pin will cause the counter to randomly reset or stay stuck at zero.

• Clock Debouncing: If you are using a mechanical push-button as a clock source, the IC will "see" dozens of pulses due to contact bounce, making the count skip unpredictably. Always use a Schmidt Trigger or a 555 Timer in monostable mode to provide a clean clock signal.

• Resetting Early: You can make the IC count to a number less than 10 (e.g., a 1-to-4 chaser). Simply connect the next sequential output (e.g., Pin 10 for Output 4) to the Reset (Pin 15). The moment the count reaches 4, it will instantly reset to 0.

• Cascading Tip: To count higher than 10, connect the Carry Out (Pin 12) of the first CD4017 to the Clock (Pin 14) of the second IC. The second IC will increment once for every full rotation of the first.

• LED Protection: When driving LEDs directly from the outputs, use a current-limiting resistor (typically 220Ω to 1kΩ). While the CD4017 can drive small LEDs, for high-power loads, use a transistor like the S8050 as a switch.

Package Includes

• 1 x CD4017BE CMOS Decade Counter IC (DIP-16)

Disclaimer: Product images are shown for illustrative purposes only. The exact color of the knobs or the branding placement on the chassis may vary slightly between manufacturing batches, but all technical specifications and the performance standards remain as described. This disclaimer also applies to any included accessories such as nozzles and stands.

Safety Warning: Ensure your power supply does not exceed 18V, as CMOS structures are susceptible to over-voltage failure. Use a 0.1µF decoupling capacitor between VDD and VSS to prevent logic glitches caused by power supply noise. Always check the orientation notch to identify Pin 1 before insertion.