An Introduction

1. Flip Flop Introduction and RS Latch
Special Slides for BSIT 3rd Morning And Evening
Made by:Israr Ahmed
BSIT 5th Evening
University of Education Lahore Okara campus (Renala Khurd)
Ask Your Queries at..
Rusaria65@mail.com

2. Flip Flop
• In electronics, a flip-flop or latch is a circuit that has
two stable states and can be used to store state
information. (Wikipedia)

3. Types of Flip Flop
Flip Flop
(Known as Latch ) (Known as F/F)
Asynchronous Synchronous
RS Latch Clock RS F/F
JK Flip Flop

4. Difference Between Synchronous & Asynchronous
Asynchronous:
• Output change immediately when input changes.
• Its event driven.
.
Synchronous:
• Output change but according to clock pulse not Immediately in
many times.
• Its clock pulse driven.

5. RS Latch
• It’s a block diagram of RS Latch.

6. Logical Diagram for RS Latch
• Active Low Latch (Using Nand Gates)

7. Truth Table for RS Latch
• It’s a truth table for RS Latch using Nand Gates.

8. Description about RS Latch
• It has two Inputs S and R
• Input S means set & input R means reset
• It has two outputs Q and Q’
• No clock pulse are used in a latch
• It can store 1 bit of data (either 1 or 0)
• It has two states whether set or reset
• In set condition it store 1 bit
• And in reset condition it store 0 bit

9. Description about RS Latch (Cont..)
• Its asynchronous device
• Inputs change output immediately when input changes.
• When S=1 and R=0 0n input then it will reset (store 0 bit)
• When S=0 and R=1 on input then it will set (store 1 bit)

10. 3rd Semester Should Say Thanks to