Electronics/Basic gates

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Basic Gates[edit]

There are 5 basic gates used in performing logic operations in Digital Electronic namely BUFFER gate, NOT gate, AND gate, OR gate, XOR gate . Each Logic Gate has A Symbol for easy to identify , a Mathematical Expression to identify mathmatic logic operation and a Truth Table to completely describe operation of the Logic Gate

Five Basic Logic Gates[edit]

Digital gates Symbol Logic Operation Mathematic Expression
BUFFER Cổng Tiếp (Buffer Gate) Y = BUFFER A Y = A
NOT NOT ANSI Labelled.svg Y = NOT A Y = \bar {A}
AND AND ANSI Labelled.svg Y = A AND B Y = A . B
OR Logic-gate-or-us.png Y = A OR B Y = A + B
XOR XOR ANSI Labelled.svg Y = A XOR B Y = {A \oplus B}

The Truth Table of the five basic logic gates above

A B Q = A Q = NOT A Q = A AND B Q = A OR B Q = A XOR B
0 0 0 1 0 0 0
0 1 0 1 0 1 1
1 0 1 0 0 1 1
1 1 1 0 1 1 0

Complement of Basic Logic gates[edit]

Basic Gates Combination Gates Symbol Mathematical Expression
BUFFER Logic-gate-inv-us.png Cổng NOT (NOT Gate) Buffer ANSI Labelled.svg Q = is NOT NOT A
Y = A
NOT Buffer ANSI Labelled.svg Cổng NOT (NOT Gate) Cổng NOT (NOT Gate) Y = is NOT A
NAND Logic-gate-and-us.png Cổng NOT (NOT Gate) NAND ANSI Labelled.svg Q = NOT A AND B
NOR Logic-gate-or-us.png Cổng NOT (NOT Gate) Logic-gate-nor-us.png Y = NOT A OR B
XNOR XOR ANSI Labelled.svg Logic-gate-inv-us.png XNOR ANSI Labelled.svg Q = NOT A XOR B

The Truth table of the combination gates above

A B Q = A Q = NOT A Q = A NAND B Q = A NOR B Q = A XNOR B
0 0 0 1 1 1 1
0 1 0 1 1 0 0
1 0 1 0 1 0 0
1 1 1 0 0 0 1

Summary[edit]

Gates Function Symbol
ANSI IEC
Buffer Q=A Buffer ANSI Labelled.svg Buffer IEC Labelled.svg
NOT gate (Inverter) Q=\overline{A} NOT ANSI Labelled.svg NOT IEC Labelled.svg
AND gate Q = A \cdot B AND ANSI Labelled.svg AND IEC Labelled.svg
NAND gate (NOT−AND) Q = \overline{A \cdot B} NAND ANSI Labelled.svg NAND IEC Labelled.svg
OR gate Q = A + B OR ANSI Labelled.svg OR IEC Labelled.svg
NOR gate (NOT−OR) Q = \overline{A + B} NOR ANSI Labelled.svg NOR IEC Labelled.svg
XOR gate (Exclusive-OR) Q = A \oplus B XOR ANSI Labelled.svg XOR IEC Labelled.svg
XNOR gate (NOT−exclusive−OR) Q = \overline{A \oplus B} XNOR ANSI Labelled.svg XNOR IEC Labelled.svg
A B Q = A Q = NOT A Q = A AND B Q = A OR B Q = A XOR B Q = A NAND B Q = A NOR B Q = A XNOR B
0 0 0 1 0 0 0 1 1 1
0 1 0 1 0 1 1 1 0 0
1 0 1 0 0 1 1 1 0 0
1 1 1 0 1 1 0 0 0 1