COMSATS UNIVERSITY
ISLAMABAD
WAH CAMPUS
DEPARTMENT OF
COMPUTER ENGINEERING
EDC PROJECT REPORT
FLIP FLOP
Submitted By:
Shamza Malik (FA23-BCE-016)
Talia Jabeen (FA23-BCE-057)
Submitted To:
Sir Adnan Mughal
PROJECT TITLE: FLIP FLOP
Introduction
A flip-flop is a fundamental building block in digital electronics used to store binary
information. It is a type of bistable multivibrator, meaning it has two stable states and can switch
between them based on input signals. Flip-flops are essential for memory storage, data
synchronization, and timing applications in digital systems. This lab report focuses on the design,
operation, and application of flip-flop circuits, specifically SR (Set-Reset) and D (Data) flip-
flops, to demonstrate their role in sequential logic.
Objective
The main objectives of this lab are:
1. To understand the working principles of different types of flip-flops.
2. To design and build SR and D flip-flop circuits.
3. To analyze the input-output behavior of flip-flops in terms of timing and state changes.
4. To study how flip-flops are used in applications like memory storage and data latching in digital
systems.
Components Required
Transistor (BC547)
Breadboard and jumper wires
9V DC power supply
2x Resistors(470 ohm & 10kohm)
LEDs (for output display)
Working:
In this simple flip-flop circuit, a single NPN transistor is used to create a bistable state. The
transistor acts as a switch that can be toggled between two states:
1. State 1 (Q = 1): When the transistor is ON, current flows from the collector to the
emitter. This turns the output ON (LED lights up) and sets Q = 1.
2. State 0 (Q = 0): When the transistor is OFF, no current flows, and the output is OFF
(LED is off), setting Q = 0.
The circuit remains in its current state until a signal or input changes the state of the transistor.
The capacitor holds the charge at the base of the transistor, ensuring that the state remains stable
until a change is triggered.
This simple flip-flop acts as a basic memory element, retaining a bit of data (either 0 or 1) until
an input changes the state.
Circuit Diagram:
Applications of flip flop:
Used to store a single bit of data in memory circuits, like registers.
Flip-flops are used in counters to track events or time in digital circuits. Used to divide the
frequency of signals in applications like clocks.
Used to hold or "latch" data in digital circuits, ensuring stable outputs.
Flip-flops are used in timing applications for generating precise timing signals or delays.
Used to divide the frequency of signals in applications like clocks.
Advantages of flip flop:
It can store a single bit of data (0 or 1) and maintain that state until changed.
It uses minimal components (e.g., a single transistor), making it energy-efficient.
The circuit is easy to design and build with basic electronic components like a transistor,
resistor, and capacitor.
It has two stable states, making it reliable for basic memory storage and data latching.
Simple flip-flops can be used in timing circuits, clock generation, and frequency division.
Disadvantages of flip flop:
It can only store one bit of data (0 or 1), so it's not suitable for larger data storage.
It needs an external signal to change its state, which makes it less flexible.
It may lose its stored data if there's a power failure or if the charge isn't held properly.
It may not work well in high-speed applications because it can be affected by noise and
instability.
Conclusion:
The simple flip-flop circuit demonstrates how a bistable circuit can store a bit of data. By using a
single NPN transistor and basic components like resistors and a capacitor, we can create a basic
memory element that holds a value until triggered to change. This circuit shows the core concept
of flip-flops, which are essential in memory storage, counters, and other sequential logic
systems.
