A logic gate is the implementation of a Boolean function. It performs a logic operation on one or more binary input. By binary I mean that the input can either be 1 or 0, nothing else.
This guide is intended to be quick guide\reference, I will dive into more details about each gate on transistor\diode level in other posts.
The guide cover gates with 2 inputs, meaning that each truth table will have 4 cases (2^2 = 4)
AND Gate:
This guide is intended to be quick guide\reference, I will dive into more details about each gate on transistor\diode level in other posts.
The guide cover gates with 2 inputs, meaning that each truth table will have 4 cases (2^2 = 4)
AND Gate:
Boolean Logic Operator: Q = A • B
Input | Output | |
---|---|---|
A | B | Q |
0 | 0 | 0 |
0 | 1 | 0 |
1 | 0 | 0 |
1 | 1 | 1 |
Summary: in order to achieve 1 on the output, both inputs A AND B must be 1
Boolean Logic Operator: Q = A + B
Input | Output | |
---|---|---|
A | B | Q |
0 | 0 | 0 |
0 | 1 | 1 |
1 | 0 | 1 |
1 | 1 | 1 |
Summary: in order to achieve 1 on the output, input A OR input B must be 1
Boolean Logic Operator: Output will be A'
Input | Output | |
---|---|
A | A' |
0 | 1 |
1 | 0 |
Summary: whatever is on the input will be inverted on the output. HIGH (1) will become LOW (0) and vice versa.
Boolean Logic Operator: Output will be the same as Input
Input | Output | |
---|---|
A | A |
0 | 0 |
1 | 1 |
Summary: whatever is on the input, will be the same on output
NAND Gate:
Boolean Logic Operator: Q = (A • B)'
The NAND gate is pretty much AND with its output connected to a NOT gate like in the figure below:
Input | Output | |
---|---|---|
A | B | Q |
0 | 0 | 1 |
0 | 1 | 1 |
1 | 0 | 1 |
1 | 1 | 0 |
Summary: in order to achieve 0 on the output, both inputs must be 1