Boolean Algebra – Introduction and Rules.

Boolean Algebra is a tool to reduce logical expressions. It is the mathematics of logical expressions, which was presented by George Boole in 1854.

What is a Binary Decoder?

The binary decoder is a device that accepts a digital input (in binary form) and it activates one of its outputs. This device has several outputs, and the one that is activated is chosen by the code applied to the inputs.

BCD Code In order to share information in digital format, it is common to use a binary or hexadecimal representations (BCD Code). There are other methods to represent this information and one of them is the BCD code. By using the BCD coding is easy to see the relationship between a decimal number (base 10) and the corresponding binary […]

Digital Logic Levels (hight, low, 0, 1)

In digital circuits is common to say that we have a “high or a “low” logic level at the input or output of a circuit. If we have a “high” level we say it is a “1” and if we have a “low” level we say that it is a “0”.

The logic NOT Gate The logic NOT gate or Inverter Gate is a logic gate that has only one input and one output. The output logic level is the opposite of the input logic level. The symbol and the truth table of the NOT gate are shown bellow. This gate is represented by the following Boolean function: X = A’. Look at the […]

Logic OR gate The logic Or gate is one of the simplest digital logic gates. The output of this gate is high, when one or all of its inputs are high. The OR gate is represented by the following Boolean function: X =A+B or X=B+A. (for a 2 input OR gate) Two Input logic OR gate The following picture shows […]

Logic AND gate The logic AND gate is one of the simplest gates in Digital Electronics. The symbols for a 2 and a 3 input AND gates are shown in the following pictures. The first one is the symbol of a 2 input AND gate and the second one is the symbol of a 3 input AND gate. […]

What is a logic Circuit?

A Logic circuit uses two logic levels to transfer the information. A hight logic level or “1” and a low logic level or “0”. The Logic circuits are made of digital elements such as the AND gate, the OR gate, the NOT gate and a combinations of them.