Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe

Understanding JK flip flop using CD4027

By Ashutosh Bhatt March 15, 2013

CD4027 is a common JK Flip flop based IC and if often used as data storing element. It contains two identical or symmetrical JK flip flop. Individual set of flip flop has provision of pin like set, reset, clock input, J, K and complementary outputs. JK flip flop can be used in applications like registers, counters or as control circuits.

[[wysiwyg_imageupload:7781:]]

Fig. 1: Prototype Of Jk Flip flop Circuit 


 

CD4027 is a master slave JK flip flop IC which works in toggle mode. Here, this IC can be used to change the state by signal applied to one or more control inputs and will have one or two outputs. In this output not only depends upon the current input. A flip flop is mostly used in computer for its memory circuit.

CD4027 has four inputs namely J, K, Set and Reset and it contain two output namely Q and Q bar(Q not) and in this both are opposite of each other. For example voltage on Q bar is zero means Q should be having higher voltage. Output at Q and Q bar depends upon how input is configured. The figure below shows the pin configuration of CD4027 IC:

Pin Diagram Of CD4027 IC

Fig. 2: Pin Diagram Of CD4027 IC

State of flip flop is controlled by the logic levels present at J and K inputs with some internal controls.  Change in state occurs at positive transition of clock pulse. In this, set and reset pin are independent of clock and they are initiated when a high signal is present on any of the input pin.

The circuit shown is triggered on the leading edge of the switch, so output changes when switch is once pressed. From the circuit you can see that both J and K are connected to high input means at every negative or positive transition the clock pulse  pin 3 toggle between high to low. This can be verified with the help of truth table described below and this stage of flip flop is known as forbidden state.

 

S

R

Q

State

0

0

Previous State

No change

0

1

0

Reset

1

0

1

Set

1

1

?

Forbidden

 

But when you press the switch a short pulse will pass into the clock input of IC which in turn makes the output pin 1 high. The output remains high till the clock input gets the second pulse. This activates the load or LED connected to output. And when this second pulse come on pin 3 the output of IC turn low and load or LED become off.

 This circuit works when you press the switch and if you want push to break circuit just interchange the position of switch and resistor.

Circuit Diagrams

Circuit-Diagram-JK-flip-flop-using-CD4027

Project Components

  • Capacitor
  • Diode 1N4148
  • LED
  • Resistor

Project Video


Filed Under: Electronic Projects
Tagged With: cd 4027, flip flop, ic, jk flip flop
 

Next Article

← Previous Article
Next Article →

Questions related to this article?
👉Ask and discuss on EDAboard.com and Electro-Tech-Online.com forums.



Tell Us What You Think!! Cancel reply

You must be logged in to post a comment.

EE TECH TOOLBOX

“ee
Tech Toolbox: 5G Technology
This Tech Toolbox covers the basics of 5G technology plus a story about how engineers designed and built a prototype DSL router mostly from old cellphone parts. Download this first 5G/wired/wireless communications Tech Toolbox to learn more!

EE Learning Center

EE Learning Center
“engineers
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EE professionals.

HAVE A QUESTION?

Have a technical question about an article or other engineering questions? Check out our engineering forums EDABoard.com and Electro-Tech-Online.com where you can get those questions asked and answered by your peers!


RSS EDABOARD.com Discussions

  • How to simulate a microstrip gap with such a reference plane
  • Phase Shift Full Bridge suffers spurious FET turn_ON
  • optimum spacing between feed and sub reflector
  • Equipment to see if household should buy battery/solar/inverter?
  • 'HERIC' pairs of IGBTs essential for Mains inverters

RSS Electro-Tech-Online.com Discussions

  • Adhesive Defibrillator Pad Cable
  • Epson crystal oscillators
  • Simple LED Analog Clock Idea
  • Fun with AI and swordfish basic
  • Microinverters and storeage batteries?

Featured – LoRa/LoRaWan Series

  • What is the LoRaWAN network and how does it work?
  • Understanding LoRa architecture: nodes, gateways, and servers
  • Revolutionizing RF: LoRa applications and advantages
  • How to build a LoRa gateway using Raspberry Pi
  • How LoRa enables long-range communication
  • How communication works between two LoRa end-node devices

Recent Articles

  • How to design a heart-rate pulse sensor BPM meter
  • Three-phase EMI filter with neutral provides >1 MOhm insulation resistance
  • Infineon adds 60 V and 150 V power MOSFETs with 30 krad(Si) TID and AEC-Q101 qualification
  • Microchip releases DSC families with 78 ps PWM resolution and 40 Msps ADCs
  • Silanna Semiconductor releases laser driver IC with 86% efficiency

EE ENGINEERING TRAINING DAYS

engineering

Submit a Guest Post

submit a guest post
Engineers Garage
  • Analog IC TIps
  • Connector Tips
  • Battery Power Tips
  • DesignFast
  • EDABoard Forums
  • EE World Online
  • Electro-Tech-Online Forums
  • EV Engineering
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • 5G Technology World
  • Subscribe to our newsletter
  • About Us
  • Contact Us
  • Advertise

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy

Search Engineers Garage

  • Electronic Projects & Tutorials
    • Electronic Projects
      • Arduino Projects
      • AVR
      • Raspberry pi
      • ESP8266
      • BeagleBone
      • 8051 Microcontroller
      • ARM
      • PIC Microcontroller
      • STM32
    • Tutorials
      • Audio Electronics
      • Battery Management
      • Brainwave
      • Electric Vehicles
      • EMI/EMC/RFI
      • Hardware Filters
      • IoT tutorials
      • Power Tutorials
      • Python
      • Sensors
      • USB
      • VHDL
    • Circuit Design
    • Project Videos
    • Components
  • Articles
    • Tech Articles
    • Insight
    • Invention Stories
    • How to
    • What Is
  • News
    • Electronic Product News
    • Business News
    • Company/Start-up News
    • DIY Reviews
    • Guest Post
  • Forums
    • EDABoard.com
    • Electro-Tech-Online
    • EG Forum Archive
  • DigiKey Store
    • Cables, Wires
    • Connectors, Interconnect
    • Discrete
    • Electromechanical
    • Embedded Computers
    • Enclosures, Hardware, Office
    • Integrated Circuits (ICs)
    • Isolators
    • LED/Optoelectronics
    • Passive
    • Power, Circuit Protection
    • Programmers
    • RF, Wireless
    • Semiconductors
    • Sensors, Transducers
    • Test Products
    • Tools
  • Learn
    • eBooks/Tech Tips
    • Design Guides
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • Digital Issues
    • EE Training Days
    • LEAP Awards
    • Podcasts
    • Webinars / Digital Events
    • White Papers
    • Engineering Diversity & Inclusion
    • DesignFast
  • Guest Post Guidelines
  • Advertise
  • Subscribe