Hex Inverter 74LS04: Datasheet, Specifications, and Pinout

     74LS04 Hex Inverter is a member of the 74XXYY IC series. The 74-series are digital logic integrated circuits, It includes six independent inverse HEX gates. Each gate consists of an input and an output. The reverse-phase is one of its main functions. The 74LS04 IC has a wide range of working voltage, a wide range of working conditions, and directly interfaces with CMOS, NMOS, and TTL.

• Supply voltage range: +4.75V to +5.25V

• Maximum supply voltage: +7V

• Maximum current allowed to draw through each gate output: 8mA

• Totally lead-free

• TTL outputs

• Maximum Rise Time: 15ns

• Maximum Fall Time: 15ns

• Operating temperature:0°C  to 70 °C

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There are many applications for this device. It has very important in inversion circuits. A few of its applications are explained here and discussed.

• It is a Universal use logic instrument used in the different logic circuit.

• It is used on different servers.

• It is used in different storage modules to store data.

• This module is also used in different personal computers and notebooks as a storing device.

• It is also used in different digital reluctance circuits and instruments.

• This module is used in different networking systems.

• It is also used in different Digital instruments and networks.

CD7404, 74LS14, A single transistor can be configured to form a NOT gate.

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Here are a few cases where 74LS04 is used.

1. The chip is basically used where a logic inverter is needed. Inverter Gates in this chip provides an output that is negated logic input. The chip has six gates that do NOT operate.

2. When you want TTL outputs. The gates in this chip provide TTL logic outputs which are a must in some applications.

3. 74LS04 is a low-cost chip available in the market and so it is used when application cost is low.

As mentioned earlier 74LS04 has six INVERTING GATES which can be used individually. The internal connection of gates can be given as below.

Now let us take a single gate of the six and connect it as shown in the circuit diagram.

For understanding the working of NOT gate, let’s redraw it in a more simplified version.

As shown in the diagram, we have a transistor forming a NOT gate. Input here is 1A which is connected to the button. Output 1Y is connected to LED through a resistor. The LED is connected to know the output status.

In the circuit,

When the button is not pressed:

The current through the base of the transistor will be zero. Because the base current is zero the transistor will be in an OFF state. Under the OFF state, the total supply voltage appears across the transistor. Under such a case, the output 1Y here will be HIGH, since the output is nothing but voltage across the transistor. Hence when a button is not pressed INPUT 1A = LOW and OUTPUT 1Y = HIGH.

When a button is pressed:

Voltage appears at the base of the transistor and current flows through it. Because the base current is present the transistor will turn ON. Under the ON state, the total supply voltage appears across the resistor and the voltage across the transistor will be zero. Under such a case, the output 1Y here will also be LOW since the output is nothing but voltage across the transistor. Hence when a button is pressed INPUT 1A = HIGH and OUTPUT 1Y = LOW.

If we draw a truth table based on the above cases, we will have.

By truth table, you can understand that OUTPUT for NOT gate is negation or inversion of INPUT. We can write the output function as, Y = A.

We have six of these gates in the 74LS04 chip. We can use one or all six of these gates depending on the requirement.

                            74LS04 Pinout                                             74HC04 Pinout   

74LS04 contains six independent gates each of which performs the logic INVERT function. The output signals of the six inverters are opposite to the input signals. The inverter can reverse the phase of the input signal by 180 degrees. This circuit is used in analog circuits, such as audio amplifiers, clock oscillators, etc.

74HC04 is a hex inverter of a CMOS circuit, and the working voltage is 2V-6V. Both 74LS04 and 74HC04 are inverters, but LS stands for low-power Schottky and HC is high-speed COMS. LS is slightly faster than HC. LS adopts TTL level. HC is CMOS level. 74HC04 is easy to understand. Input low level, output high level. Input high level, output low level.