Hex Inverting NOT Gate



To study and verify the truth table of Hex Inverting NOT Gate.

Learning Objectives

  1. To understand the behavior and demonstrate the operation of Hex Inverting NOT Gate.
  2. To apply knowledge of the fundamental gates to create truth tables.
  3. To develop digital circuit building and troubleshooting skills.
  4. To understand key elements of TTL logic specification or datasheets.

IC Used

For Hex Inverting NOT Gate:
IC NumberIC Name
74LS04Hex Inverting Gates

Circuit Tutorials:


  1. Place the IC on IC Trainer Kit.
  2. Connect VCC and ground to respective pins of IC Trainer Kit.
  3. Implement the circuit as shown in the circuit diagram.
  4. Connect the inputs to the input switches provided in the IC Trainer Kit.
  5. Connect the outputs to the switches of O/P LEDs
  6. Apply various combinations of inputs according to the truth table and observe the condition of LEDs.
  7. Note down the corresponding output readings for various combinations of inputs.
  8. Power Off Trainer Kit, disconnect all the wire connections and remove IC's from IC-Base.


NOT GATE - It is a digital circuit that has a single input and single output. The output of NOT gate is the logical inversion of input. Hence, the NOT gate is also called an inverter.

Logic NOT Gates are available using digital circuits to produce the desired logical function. The standard NOT gate is given a symbol whose shape is of a triangle pointing to the right with a circle at its end. This circle is known as an "inversion bubble". Logic NOT gates provide the complement of their input signal and are so called because when their input signal is "HIGH" their output state will NOT be "HIGH". Likewise, when their input signal is "LOW" their output state will NOT be "LOW". As they are single-input devices, logic NOT gates are not normally classed as "decision" making devices

Boolean Expression Y = A'

"If A is true, then Y is false"

This NOT gate produces an output Y, which is the complement of input, A.

Block Diagram


  1. Make the connections according to the IC pin diagram.
  2. The connections should be tight on trainer kit.
  3. The Vcc and ground should be applied carefully at the specified pin only.


We have learned the Hex Inverting NOT Gate IC according to the IC pin diagram.