Logic Gates

Introduction

• Logic gates are basic building blocks of digital systems.
• Comprise electronic circuits with one or more inputs and one output.
• Inputs and outputs can have two values: Logic 1 (high) or Logic 0 (low).
  • High = 5V, Low = 0V.
• Logic gates make logical decisions based on input values.

Types of Logic Gates

Basic Logic Gates

1. AND Gate

   • Symbol: Two inputs (A, B) and output (Y)
   • Function: Output is high (1) only when both inputs are high.
   • Truth Table:
     • (0, 0) -> 0
     • (0, 1) -> 0
     • (1, 0) -> 0
     • (1, 1) -> 1
   • Boolean Expression: Y = AB

2. OR Gate

   • Symbol: Two inputs (A, B) and output (Y)
   • Function: Output is low (0) only when both inputs are low.
   • Truth Table:
     • (0, 0) -> 0
     • (0, 1) -> 1
     • (1, 0) -> 1
     • (1, 1) -> 1
   • Boolean Expression: Y = A + B

3. NOT Gate (Inverter)

   • Symbol: Input (A) and output (Y)
   • Function: Output is the complement of the input.
   • Truth Table:
     • (0) -> 1
     • (1) -> 0
   • Boolean Expression: Y = A'

Universal Gates

1. NAND Gate

   • Symbol: Two-input NAND gate (similar to AND with a bubble on output)
   • Function: Output is the complement of the AND gate.
   • Truth Table:
     • (0, 0) -> 1
     • (0, 1) -> 1
     • (1, 0) -> 1
     • (1, 1) -> 0
   • Boolean Expression: Y = (AB)'

2. NOR Gate

   • Symbol: Two-input NOR gate (similar to OR with a bubble on output)
   • Function: Output is the complement of the OR gate.
   • Truth Table:
     • (0, 0) -> 1
     • (0, 1) -> 0
     • (1, 0) -> 0
     • (1, 1) -> 0
   • Boolean Expression: Y = (A + B)'

Additional Gates

• XOR Gate: Exclusive OR
• XNOR Gate: Exclusive NOR
• These gates will be discussed in the next video.

Conclusion

• Understanding of logic gates and their functions.
• Encouragement to reach out with questions or suggestions.
• Reminder to like and subscribe for more content.