The logic NAND function is a combination of the two separate logical functions, the AND function and the NOT function (NOT-AND) in series. The logic NAND function can be expressed by the Boolean expression of, A.B
The Logic NAND Function will not produce an output when “ALL” of its inputs are present and in Boolean Algebra terms the output will be FALSE only when all of its inputs are TRUE.
Switch Representation
The truth table for the NAND function is the opposite of that for the previous AND function because the NAND gate performs the reverse operation of the AND gate. In other words, the NAND gate is the complement of the basic AND gate.
NAND Function Truth Table
Switch A |
Switch B |
Output |
Description |
0 |
0 |
1 |
A and B are both open, lamp ON |
0 |
1 |
1 |
A is open and B is closed, lamp ON |
1 |
0 |
1 |
A is closed and B is open, lamp ON |
1 |
1 |
0 |
A is closed and B is closed, lamp OFF |
Boolean Expression (A AND B) |
A . B |
The NAND Function is sometimes known as the Sheffer Stroke Function and is denoted by a vertical bar or upwards arrow operator, for example, A NAND B = A|B or A↑B.
The logic NAND function is the opposite and complement of the AND function with its name being an abbreviation of “NOT-AND”. The NAND function is classed as a universal function since it can implement any other Boolean function without need to use other logical function types.
Logic NAND gates are used as the basic “building blocks” to construct other logic gate functions and are available in standard i.c. packages such as the very common TTL 74LS00 Quadruple 2-input NAND Gates, the TTL 74LS10 Triple 3-input NAND Gates or the 74LS20 Dual 4-input NAND Gates. There is even a single chip 74LS30 8-input NAND Gate.
its good
It’s so great to know how logic things functions
The illustrated table here shows that the output state is the negation of AND output result.
Can you tell me in the diagram “Switch Representation of the NAND Function” why does the light not light when the switches are closed? Wouldn’t electricity flow down every path?
Thanks so much as there is something I am missing here.
With switch “A” open, or switch “B” open, or both switches open together, the lamp will alight. With switch “A” closed AND switch “B” closed, the lamp is shorted by the switches so will not be alight as represented by the truth table
Hi, i would like to know why does no current flow into the lamp.
What is NAND Gate
Please make an effort to read the tutorial or visit NAND Gate Tutorial
NYC one there
How to solve complicated circuit when question ask find combination of circuit?
Nice
If it explains the full circuit diagram then it is so good and clearly understand
yes pleas esplain more. please
What circuit diagram, please explain more.
Sorry, but isn’t the circuit representation above for NOR gate? It only produces an output of 0 when both of the inputs are 1…..
How specify nand gate in sr latch
I need a to be helped about NAND GATE just to draw the circuit….
Please read the Nand Gate tutorial
Sorry, English only.
very nice…………………..
very nice
thanks i have cleared my doubt