Mumbai University > Information Technology > sem 3> Analog and Digital Circuits

Marks: 4M

Year: Dec15

Universal Gate:

A Logic Gate which can infer any of the gate among Logic Gates. OR a gate which can be use to create any Logic gate is called Universal Gate

We have following Logic Gates:

NOT

AND

OR

NAND

NOR

XOR

XNOR

NAND and NOR Gates are called Universal Gates because all the other gates can be created by using these gates

1. NAND gate to NOT Gate conversion

Refer the following diagram –

Here the same input is applied to the both inputs of a NAND Gate

According to NAND Gate – If A and B are two inputs than output equation will be (A.B)’

For this case :

= (X.X)’

= X’

2. NAND Gate to AND Gate Convertion

Refer following diagram for NAND to and Gate conversion –

For this case – x and y are the two inputs to a NAND gate and the output of the First NAND gate goes again to an another NAND gate’s inputs.

=> s1 = (X.Y)’

=> s2 = (s1.s1)’ = s1’

=> s2 = ((X.Y)’)’

=> X.Y

3. NAND Gate to OR Gate Conversion

Refer the following Diagram

According to diagram – s1 = (X.X)’ = X’ s2 = (Y.Y)’ = Y’ s3= (s1.s2)’ = (X’.Y’)’ => (X’)’ + (Y’)’ => X+Y

4. NAND Gate to NOR Gate Convertion

Refer the following Diagram

According to diagram –

s1 = (X.X)’ = X’

s2 = (Y.Y)’ = Y’

s3= (s1.s2)’ = (X’.Y’)’

=> (X’)’ + (Y’)’

=> X+Y

s4 = (s3.s3)’ = s3’

=> (X + Y)’