Flip flop: Different Types Of flip flop

The flip flop is the smallest unit of memory. It has only a bit. Numerous of the flip-flop creates a memory. The flip flop is also called a latch. Flip-flop or latch is a circuit that has two stable states and can be used to store state information.

A flip-flop is a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic. Different Types Of flip flop

NAND latch


Figure: NAND latch and Truth table

S R Q
0 0 No Change
0 1 0  (Reset)
1 0 1 (Set)
1 1 Invalid

Different Types Of flip flop

1.S-R flip flop

2.J-K flip flop

3.D-type flip flop

4.T-type flip flop

1.S-R flip flop:

SR flip flop operates with only positive clock transitions or negative clock transitions. Whereas, SR latch operates with enable signal. The circuit diagram of SR flip flop is shown in the following electronics design.

S-R flip-flop
S-R flip flop

This circuit has two inputs S & R and two outputs Q & Q’. The operation of SR flip flop is similar to SR Latch. But, this flip flop affects the outputs only when a positive transition of the clock signal (E) is applied instead of active enable.

The following table shows the state table of SR flip flop:

Calk(E) S R Q
  != up 0 0 Q
  !=up 0 1 0
  !=up 1 0 1
  !=up 1 1 ID

2. JK flip flop:

JK flip-flop is the modified version of SR flip flop. It operates with only positive clock transitions or negative clock transitions. The circuit diagram of JK flip flop is shown in the following electronics design.

JK flip-flop circuit diagram
JK flip flop circuit diagram

This circuit has two inputs J & K and two outputs Q & Q’. The operation of JK flip flop is similar to SR flip flop. SR flip-flop for 4 combinations of inputs.

The following table shows the state table of JK flip flop:

Calk(E) J K Q
  !=up 0 0 Q
  !=up 0 1 0
!=up 1 0 1
  !=up 1 1 Toggle

3.D flip flop:

D flip-flop operates with only positive clock transitions or negative clock transitions. Whereas, D latch operates with enable signal.

That means the output of D flip flop is insensitive to the changes in the input, D except for active transition of the clock signal. The circuit diagram of the D flip flop is shown in the following figure.

D flip-flop
D flip-flop

           This circuit has single input D and two outputs Q(t)& Q(t)’. The operation of the D flip-flop is similar to D Latch. But, this flip flop affects the outputs only when a positive transition of the clock signal is applied instead of active enable.

Clk D Q(t) Mood
!=up 0 0 Storage
!=up 1 1 Toggle

Different Types Of flip flop and it’s difference.There Difference between JK and Sr flip-flop:

SR Flip Flop JK Flip Flop
SR flip flop is single stage flip flop JK flip flop is multistage flip flop
It has 2 input It has 3 input
No default Application Default Application
It has an invalid mood It has a toggle mood

Leave a Reply

Your email address will not be published. Required fields are marked *

Shares