An OR gate is another essential digital logic gate that performs a logical OR operation on two or more binary inputs to generate a single binary output. The output of an OR gate is high (1) if at least one of its input signals is high (1). It produces a low (0) output only when all of its inputs are low (0).

The logic symbol for an OR gate is represented as follows:

   ----       ----
A |    |    B |    |
  | OR  |      |    |
---|    |    ---|    |
   ----       ----
     Output

In this symbol:

  • A and B represent the input signals.
  • The OR symbol in the middle represents the logical OR operation.
  • The output is the result of the OR operation.

The truth table for a 2-input OR gate is as follows:

ABOutput
000
011
101
111

The truth table shows the output for all possible combinations of input values. As per the truth table, the output is 1 when at least one input is 1.

OR gates have various applications in digital systems, including:

  • Combining multiple binary inputs to produce a control signal.
  • Logic circuits for decision-making and control.
  • Memory circuits for addressing and data retrieval.
  • Arithmetic circuits for binary addition and logical operations.
  • Communication systems for data encoding and signal processing.

When combined with other logic gates like AND and NOT gates, OR gates are used to design more complex logic functions and digital circuits to perform a wide range of tasks in various electronic devices and systems.