Author: M Abo Bakar Aslam

NOR Gate

The NOR gate is the inverse of the OR gate and produces HIGH only when all inputs are LOW. It is a universal gate used to build any digital circuit.

Click here if you want to know how this gate will act as universal gate.

1. Properties

Minimum two inputs
It inverts output of OR Gate. It is a combination of OR followed by NOT.

NOR Gate is Combination of AND and NOT Gate — Figure 1: NOR Gate is Combination of OR and NOT Gate

2. Symbol - 2 Inputs NOR Gate

NOR Gate with 2 Inputs — Figure 2: NOR Gate with 2 Inputs

3. Boolean Expression - 2 inputs NOR Gate

Y = (A + B)'

4. Truth Table - 2 Inputs NOR Gate

Total Number of Rows = 2^(number of inputs) = 2^2 = 4

Total Numbers: 0, 1, 2, 3

A	B	A+B	Y
0	0	0	1
0	1	1	0
1	0	1	0
1	1	1	0

5. NOR Gate with Multiple Inputs

NOR Gate with 3 Inputs — Figure 3: NOR Gate with 3 Inputs

NOR Gate with 4 Inputs — Figure 4: NOR Gate with 4 Inputs

NOR Gate with 1 Inputs — Figure 5: NOR Gate with 1 Inputs